Patent Publication Number: US-8109949-B2

Title: Systems for forming an anastomosis

Description:
RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 09/737,200, entitled Compression Plate Anastomosis Apparatus and Related Systems, filed Dec. 14, 2000; U.S. application Ser. No. 09/737,200 is a continuation-in-part of U.S. application Ser. No. 09/460,740, entitled Compression Plate Anastomosis Apparatus, filed Dec. 14, 1999, now U.S. Pat. No. 6,569,173, and is also a continuation-in-part of U.S. application Ser. No. 09/293,617, entitled Anastomosis Apparatus For Use in Intraluminally Directed Vascular Anastomosis, filed Apr. 16, 1999, now U.S. Pat. No. 6,248,117. Each of the foregoing applications is incorporated herein by specific reference. 
    
    
     BACKGROUND 
     1. The Field of the Invention 
     The present invention is directed generally to anastomosis methods, systems and devices. More specifically the present invention is directed to compression plate vascular anastomosis methods, systems and devices with the use of a vascular anvil. 
     2. Relevant Technology 
     Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings. 
     Endoscopic applications are generally used in intracavity procedures such as intrathoracic and intraabdominal procedures. Peripheral techniques are usually employed in other body regions, such as arms and legs. It is desirable to be able to provide by active endoscopic or peripheral procedures a variety of medical services that are currently provided by techniques that are more invasive and more demanding in time and in medical resources and skills. This goal is justified by the efficiency, effectiveness, safety, low cost, and preventive accomplishments of active endoscopic or peripheral procedures. In particular, this invention provides new methods, devices and systems for performing vascular anastomoses by intraluminally directed active endoscopic or peripheral procedures. The intraluminally directed or intravascular part of the procedures of this invention is based on an examination performed by, for example, fluoroscopy, and extraluminal manipulation is performed endoscopically or according to a peripheral technique. 
     One aspect of this invention encompasses the quasi-simultaneity of the exploration, diagnosis and corrective tasks that can be achieved in vascular anastomoses performed by the active endoscopic or peripheral procedures of this invention. Another aspect of this invention includes the minimally invasive character of the vascular anastomoses that are performed by the active endoscopic or peripheral procedures of this invention. These procedures are also characterized by comparatively reduced requirements of medical facilities and skill. To more effectively describe and enable the present invention, a review of some basic terminology and related technology is offered in the immediately following subsections. 
     2.1. Terminology 
     An anastomosis is an operative union of two hollow or tubular structures. Anastomotic structures can be part of a variety of systems, such as the vascular system, the digestive system or the genitourinary system. For example, blood is shunted from an artery to a vein in an arteriovenous anastomosis, and from the right pulmonary artery to the superior vena cava in a cavopulmonary anastomosis. In other examples, afferent and efferent loops of jejunum are joined in a Braun&#39;s anastomosis after gastroenteroscopy; the ureter and the Fallopian tube are joined in a ureterotubal anastomosis, and the ureter and a segment of the sigmoid colon are joined in a ureterosigmoid anastomosis. In microvascular anastomosis, very small blood vessels are anastomosed usually under surgical microscope. 
     An anastomosis is termed end-to-end when the terminal portions of tubular structures are anastomosed, and it is termed end-to-side when the terminal portion of a tubular structure is anastomosed to a lateral portion of another tubular or hollow structure. In an end-to-side anastomosis, we often refer to the structure whose end is anastomosed as the “graft vessel” while the structure whose side wall is anastomosed is referred to as the “receiving structure”. 
     Anastomotic material typically includes autologous material, but it can also include heterologous material or synthetic material. An autologous graft is a graft in which the donor and recipient areas are in the same individual. Heterologous material is derived from an animal of a different species. The graft can be made of a synthetic material such as expanded polytetrafluoroethylene (“ePTFE”). Wolf Dieter Brittinger, Gottfried Walker, Wolf-Dieter Twittenhoff, and Norbert Konrad, Vascular Access for Hemodialysis in Children, Pediatric Nephrology, Vol. 11 (1997) pp. 87-95. 
     A nonocclusive anastomosis is typically an end-to-side anastomosis in which the flow of matter through the vessel that is anastomosed in its side is not interrupted while the anastomosis is performed. Most conventional techniques for vascular anastomosis require the interruption of blood flow through the receiving vessel while the anastomosis is performed. 
     Although the parts of a blood vessel are designated by well-known terms in the art, a few of these parts are briefly characterized here for introducing basic terminology. A blood vessel is in essence a tubular structure. In general, the region comprised within tubular walls, such as those defining a blood vessel or the walls defining the tubular member of an endoscope, is termed the lumen or the intraluminal space. A lumen that is not occluded is a patent lumen and the higher the patency of a blood vessel, the less disrupted the blood flow through such vessel is. A reduction of a blood vessel&#39;s patency can be caused by a stenosis, which is generally a stricture or narrowing of the blood vessel&#39;s lumen. A hyperplasia, or tissue growth, can also reduce a blood vessel&#39;s patency. Reduction of blood vessel patency, and in general a disruption in a vessel&#39;s blood flow, can lead to ischemia, which is a local lack of oxygen in tissue due to a mechanical obstruction of the blood supply. 
     A stent is a device that can be used within the lumen of tubular structures to assure patency of an intact but contracted lumen. Placement of a stent within an occluded blood vessel is one way of performing an angioplasty, which is an operation for enlarging a narrowed vascular lumen. Angioplasty and bypass are different ways for reestablishing blood supply, an operation that is called revascularization. 
     A blood vessel is composed of three distinct layers. From inside to outside, these layers include the intima, the media and the adventitia. The intima is a single layer of flat cells that collectively line the lumen. The media is a thick middle layer composed of smooth muscle cells. The adventitia is an outer layer that comprises fibrous covering. 
     Angiography is a technique for performing a radiograph of vessels after the injection of a radio-opaque contrast material. This technique usually requires percutaneous injection of a radio-opaque catheter and positioning under fluoroscopic control. An angiogram is a radiograph obtained by angiography. Fluoroscopy is an examination technique with an apparatus, the fluoroscope, that renders visible the patterns of X-rays which have passed through a body under examination. 
     2.2 Related Technology 
     The operative union of two hollow or tubular structures requires that the anastomosis be tight with respect to the flow of matter through such structures and also that the anastomosed structures remain patent for allowing an uninterrupted flow of matter therethrough. For example, anastomosed blood vessels should not leak at the anastomosis site, the anastomotic devices should not significantly disrupt the flow of blood, and the anastomosis itself should not cause a biological reaction that could lead to an obstruction of the anastomosed blood vessels. In particular, anastomosed blood vessels should remain patent and they should ideally not develop hyperplasia, thrombosis, spasms or arteriosclerosis. 
     Because anastomosed structures are composed of tissues that are susceptible to damage, the anastomosis should furthermore not be significantly detrimental to the integrity of these tissues. For example, injury to endothelial tissue and exposure of subintimal connective tissue should be minimized or even eliminated in vascular anastomosis. 
     Because structures to be anastomosed are internal, an anastomosis requires a degree of invasion. The invasive character of an anastomosis, however, should be minimized subject to the reliable performance of a satisfactory anastomosis. Accordingly, there has been a noticeable trend during the last quarter of this century towards less invasive surgical intervention, a surgical style that is termed minimally invasive surgery. This style is characterized by pursuing a maximal treatment effect with minimal damage to surrounding and overlying normal structures. In addition, successful minimally invasive procedures should procure patency and they should minimize damage to the tissues of the anastomosed structures themselves. 
     A plurality of factors provide a propitious environment for this trend towards minimally invasive surgery. These factors include the development of high-technology diagnostic devices, the innate characteristics of human psychology and economic imperatives. 
     High-technology diagnostic devices such as flexible fiber-optic endoscopes and intravascular catheters have considerably enhanced our ability for performing a reliable spacio-temporal location of disease. More specifically, these devices permit the early and accurate determination of disease processes and their loci. Furthermore, it is known that the earlier a tumor or growth can be identified, the more responsive it is to therapy by a minimally invasive technique. See Rodney Perkins, Lasers in Medicine in Lasers—invention to Application, edited by John R. Whinnery, Jesse H. Ausubel, and H. Dale Langford, p. 104, National Academy of Engineering, National Academy Press, Washington, D.C. 1987. (This article will hereinafter be referred to as “Lasers—Invention to Application”). See also Edward R. Stephenson, Sachin Sankholkar, Christopher T. Ducko, and Ralph J. Damiano, Robotically Assisted Microsurgery for Endoscopic Coronary Artery Bypass Grafting, Annals of Thoracic Surgery, Vol. 66 (1998) p. 1064. (This article will hereinafter be referred to as “Endoscopic Coronary Artery Bypass Grafting”). 
     Human psychology also contributes to the growing trend towards minimally invasive techniques. This is attributed to the accepted prevailing preference of a minimally invasive technique with respect to a more invasive surgical technique whenever the outcomes of these two techniques are equivalent. 
     Finally, minimally invasive techniques are generally cost effective to insurers and to society in general because they are performed on an outpatient basis or else they require comparatively shorter hospitalization time. Furthermore, the less tissue is invasively effected in a procedure, the more likely it is that the patient will recover in a comparatively shorter period of time with lower cost hospitalization. Therefore, economic factors also favor the development of minimally invasive techniques because they can be performed with lower morbidity risk and they satisfy economic imperatives such as reduced cost and reduced loss of productive time. See Rodney Perkins in Lasers—Invention to Application, p. 104; Endoscopic Coronary Artery Bypass Grafting, pp. 1064, 1067. 
     Particularly in the field of vascular anastomosis, it is acknowledged that there is an increasing demand for an easier, quicker, less damaging, but reliable procedure to create vascular anastomosis. This demand is further revitalized by the movement of vascular procedures towards minimally invasive procedures. See Paul M. N. Werker and Moshe Kon, Review of Facilitated Approaches to Vascular Anastomosis Surgery, Annals of Thoracic Surgery, Vol. 63 (1997) pp. S122-S127. (This work will hereinafter be referred to as “Review of Facilitated Approaches to Vascular Anastomosis”). 
     Conventional exploration and anastomosis techniques are not always implemented in such a way as to satisfy the demand for an easier, quicker, less damaging, but reliable vascular anastomosis. The following overview of conventional exploration and anastomosis techniques closes this background section on related technology. 
     Exploration of a blood vessel typically provides necessary information for locating and diagnosing vascular abnormalities such as those that reduce vascular patency. This exploration can rely on examination techniques such as angiography and endoscopy. Vascular abnormalities are usually detected fluoroscopically according to an angiography procedure. When it is concluded that the appropriate corrective action requires an anastomosis, conventional procedures ordinarily follow a sequence in which the anastomosis is not performed at the time when the initial exploration and diagnostic are performed, but at a later time and in a typically different clinical setup. Accordingly, the time and resources that are spent during the exploration and diagnostic phases are not directly employed in the performance of an appropriate corrective action, such as an anastomosis. 
     By performing an anastomosis considerably after the initial exploration has taken place and in a different location and clinical environment, these conventional procedures also waste a significant part of the information acquired at the exploration phase. Images obtained during an angiographic procedure are typically recorded on film or digital medium. In current clinical practice, these recorded images are reviewed in a subsequent clinical setting and based upon a knowledge of external anatomy, the lesion location and optimal site for anastomosis are estimated. This process sacrifices potentially useful information. Fluoroscopic visualization is no longer available without repeating the angiogram procedure, and in conventional practice external anatomic localization is used in correlation with previously recorded images. In addition to this external inspection, conventional procedures could rely on imaging for determining the optimal anastomosis site when corrective action is taken. However, having to reacquire information leads to a waste of resources, it significantly increases the period of time from exploration to corrective action, it is an additional burden on the patient, and it enhances the invasive character of the treatment that is administered to the patient. Furthermore, reacquisition of information might have to be done in an environment that demands higher skills and more resources than they would have been otherwise needed. For example, the opening of a body cavity to expose the anatomical region around a potential anastomosis site, the determination of the optimal anastomosis site by external inspection, and the surgical performance of the anastomosis are part of a treatment that is more complex, requires practitioners with more training, and may be more time and resource consuming than the treatment provided by the methods, systems and apparatuses of the present invention. 
     Vascular anastomosis techniques can be classified in a plurality of groups. Although with various degrees of success, all these techniques generally intend to provide leak-proof joints that are not susceptible to mechanical failure, and they also intend to minimize damage and reduce the undesirable effects of certain operational features that may lead to post-anastomosis complications. Damage to be minimized and operational features whose undesirable effects should be reduced include endothelial coverage injury, exposure of subintimal connective tissue, exposure of an intraluminal foreign component, blood flow interruption, irregularities at the junction, adventitial tissue stripping, intimal injury, installment of a foreign rigid body, use of materials that may have toxic effects, damage to surrounding tissue, extensive vessel eversion, and tissue plane malalignment. Post-anastomosis complications include intimal hyperplasia, atherosclerosis, thrombosis, stenosis, tissue necrosis, vascular wall thinning, and aneurism formation. In addition, vascular anastomosis techniques are characterized by varying abilities to successfully cope with the dilating character of the structures to be anastomosed, their diversity in size, and the possibility that at least one structure may grow after the anastomosis has been performed. Other variables that partially determine the suitability of a specific anastomosis technique include the nature of the material to be anastomosed (for example, autologous, heterologous, or synthetic), the desired reduction in operative time, the skill requirements, and the healing time. 
     Each one of the techniques discussed hereinbelow for joining anastomosed structures presents a compromise for reducing undesirable effects in the practice of vascular anastomosis. High standards in one or a few aspects of the anastomosis can sometimes be achieved only at the expense of sacrificing what otherwise would have been the benefits of other aspects of the anastomosis. 
     Since early in the 20th century when vessel anastomoses were performed with an acceptable degree of reliability, the standard for creation of a vascular anastomosis has been manual suturing. Review of Facilitated Approaches to Vascular Anastomosis, p. S122. Suturing devices and methods are still being developed with the aim at performing less invasive surgical procedures within a body cavity. See, for example, U.S. Pat. No. 5,860,992 disclosing devices and methods for suture placement while performing less invasive procedures. 
     Regarding the application of sutures in vascular anastomoses, it has been generally reported that “the insertion of transmural stitches, even in experienced hands that employ a traumatic techniques and fine sutures, causes significant damage to the vessel wall. As the result of this the subendothelial matrix becomes exposed to the bloodstream and initiates the formation of a thrombus. The same process takes place at the actual site of the anastomosis in the case of intima-intima apposition. These processes are multifactorial but can cause obstruction of the complete anastomosis, especially in small vessels.” Review of Facilitated Approaches to Vascular Anastomosis, p. S122. In addition to proximal occlusion, needle-and-suture-mediated intimal penetration is believed to represent a source of platelet emboli, which can cause distal embolization and thus a hazard in brain revascularization and myocardial circulation. Patrick Nataf, Wolff Kirsch, Arthur C. Hill, Toomas Anton, Yong Hua Zhu, Ramzi Ramadan, Leonardo Lima, Alain Pavie, Christian Cabrol, and Iradj Gandjbahch, Nonpenetrating Clips for Coronary Anastomosis, Annals of Thoracic Surgery, Vol. 63 (1997) p. S137. (This article will hereinafter be referred to as “Nonpenetrating Clips for Coronary Anastomosis”). Furthermore, it is considered that “suture anastomosis of small vessels is time-consuming and tedious and demands a long and continuous training if high patency rates are to be regularly achieved.” Willy D. Boeckx, Oliskevigius Darius, Bert van den hof, and Carlo van Holder, Scanning Electron Microscopic Analysis of the Stapled Microvascular Anastomosis in the Rabbit, Annals of Thoracic Surgery, Vol. 63 (1997) p. S128. (This work will hereinafter be referred to as “Microscopic Analysis of Stapled Microvascular Anastomosis”). In contrast, in all specialties that employ vascular surgery, “there is an increasing demand for a simple, time-saving, but reliable automated, semiautomated, or at least facilitated method to replace the process of manually sutured anastomosis. The most important reason for this demand is the movement of cardiac bypass surgery toward a minimally invasive and possibly even an endoscopic procedure.” Review of Facilitated Approaches to Vascular Anastomosis, p. S122. In this respect, improvement “may come from techniques that do not lead to exposure of [a] damaged vessel wall to the bloodstream” Id., p. S122. 
     Besides the group that includes techniques which rely on suturing, vascular anastomosis techniques can generally be classified in four groups depending on how the tissue is joined and on the type of device or material used for joining the tissue of the anastomosed vessels. These groups are: Stapling and clipping techniques, coupling techniques, pasting techniques, and laser techniques. Id., pp. S122-S127. 
     2.2.1. Stapling and Clipping Techniques 
     Although some staplers have been reported as providing leaky joints, a variety of staplers have been developed for end-to-end and for end-to-side anastomosis. U.S. Pat. No. 5,366,462 discloses a method of end-to-side vascular anastomosis. According to this method, the end of the graft blood vessel that is to be anastomosed is everted by 180.degree.; one end of the staple pierces both vessels with punctures exposed to the blood flow and the other end of the staple pierces the outside of the receiving vessel. U.S. Pat. No. 5,732,872 discloses a surgical stapling instrument that comprises an expandable anvil for aiding in the stapling of a 180.degree. everted end of a graft vessel to a receiving vessel. This patent also discloses a stapling instrument for joining the 180.degree. everted second end of a graft vessel whose opposite end has already been anastomosed. To anastomose this second end, this technique requires clearance around the area in which the anastomosis is performed, exposure of the receiving blood vessel, external anatomic identification, and significant external manipulation in the open area around the anastomosis site. U.S. Pat. No. 4,930,674 discloses methods of end-to-end and end-to-side anastomosis and a surgical stapler that comprises a vessel gripping structure for joining the 180.degree. everted end of a graft vessel to another vessel. U.S. Pat. No. 5,695,504 discloses methods and a system for performing an end-to-side vascular anastomosis, where the system is applicable for performing an anastomosis between a vascular graft and the ascending aorta in coronary artery bypass surgery, particularly in port-access coronary artery bypass graft surgery. This system includes a staple with a configuration that combines the functions of an anchor member and a coupling member into a one-piece anastomosis staple. U.S. Pat. No. 5,861,005 discloses an arterial stapling method and device for stapling an opening in an anatomical structure, whether the opening is deliberately formed or accidentally caused. This device employs a balloon catheter that helps positioning the stapling mechanism properly on the organ to be stapled. 
     Some stapling devices rely on access to the anastomosis area through an opening that might be as big as or comparable to typical openings that are required in surgical procedures. Furthermore, the 180.degree. eversion of vessel ends is viewed as an operation that can be difficult, particularly in sclerotic vessels. Review of Facilitated Approaches to Vascular Anastomosis, p. S123. 
     In general, clipping techniques rely on arcuate legged clips for achieving a flanged, nonpenetrated, intimal approximation of the anastomosed structures. Reportedly, the use of s clips leads to a biologically and technically superior anastomosis as compared to the penetrating microsuture. Review of Facilitated Approaches to Vascular Anastomosis, p. S123. By approximating the everted walls of the two vessels to be anastomosed, a clipping technique avoids stitching and reportedly the subsequent risk of intimal hyperplasia. Gianfranco Lisi, Louis P. Perrault, Philippe Menasche, Alain Bel, Michel Wassef, Jean-Paul Vilaine, and Paul M. Vanhoutte, Nonpenetrating Stapling: A Valuable Alternative to Coronary Anastomoses, Annals of Thoracic Surgery, Vol. 66 (1998) p. 1707. In addition, maintenance of an uninjured endothelial coverage and avoidance of exposure of subintimal connective tissue are considered important features because “regenerated endothelium presents selective dysfunction that may predispose to spasm and atherosclerosis, thereby affecting both medium-term and long-term graft patency” and the risk of thrombosis at the anastomotic site can be reduced. Id., p. 1707. 
     Nonpenetrating vascular closure staples (“VCS”) have been used in anastomoses performed to provide access for dialysis, as well as in kidney and pancreas transplantation. It has been concluded in light of these anastomoses that “the fact that VCS staples are interrupted and do not disrupt the endothelium or have an intraluminal component makes them ideal” for achieving the goals of kidney transplantation. V. E. Papalois, J. Romagnoli, and N. S. Hakim, Use of Vascular Closure Staples in Vascular Access for Dialysis, Kidney and Pancreas Transplantation, International surgery, Vol. 83 (1998) p. 180. These goals include the avoidance of post-operative thrombosis and the avoidance of renal artery stenosis. As with kidney transplants, no anastomotic abnormalities were detected in pancreatic transplants, where the avoidance of arterial stenosis is also very important. Id., p. 180. The results of anastomoses performed for providing vascular access for dialysis were also reported successful. Id., p. 179. In addition, it has been reported that the “VCS applier is easy to manipulate, is as safe as hand-suture methods, and has time saving potential. VCS clips are useful for vascular anastomoses of blood access.” Hiroaki Haruguchi, Yoshihiko Nakagawa, Yasuko Uchida, Junichiro Sageshima, Shohei Fuchinoue and Tetsuzo Agishi, Clinical Application of Vascular Closure Staple Clips for Blood Access Surgery, ASAIO Journal, Vol. 44(5) (1998) pp. M562-M564. 
     In a study of microvascular anastomosis of rabbit carotid arteries, some anastomosis were stapled using non-penetrating 0.9 mm microclips and some anastomosis were conventionally sutured Arcuate-legged, nonpenetrating titanium clips are applied according to a clipping technique in an interrupted fashion to everted tissue edges at high compressive forces. It is considered that this technique “enables rapid and precise microvascular reconstructions, but requires both training and evertable tissue walls.” Nonpenetrating Clips for Coronary Anastomosis, Annals of Thoracic Surgery, p. S135. An example of this clip applier is the VCS device, Autosuture, United States Surgical Corporation, Norwalk, Conn. Nonpenetrating Clips for Coronary Anastomosis, pp. S135-S137. U.S. Pat. No. 5,702,412 discloses a method and devices for performing end-to-side anastomoses where the side wall of one of the structures is cut from the intraluminal space of the graft vessel and the anastomosed structures can be secured by a plurality of clips or by suturing. 
     It has been concluded that stapled microvascular anastomosis is fast and reliable and histomorphologic examination of the anastomotic site revealed no major differences between sutured and stapled groups. Microscopic Analysis of Stapled Microvascular Anastomosis, p. S128. Furthermore, it has also been reported that the “clipped anastomotic technique has a rapid learning curve, the same safety as suture methods, and the potential for facilitating endoscopic vascular reconstruction.” Nonpenetrating Clips for Coronary Anastomosis, p. S135. In a study undertaken to compare VCS clips with sutured arterial end-to-end anastomosis in larger vessels, it was concluded that this type of anastomosis “can be performed more rapidly with VCS clips than continuous sutures”, and that VCS clips “are potentially useful situations where the clamp time of the vessel is critical.” Emmanouil Pikoulis, David Burris, Peter Rhee, Toshiya Nishibe, Ari Leppniemi, David Wherry and Norman Rich, Rapid Arterial Anastomosis with Titanium Clips, The American Journal of Surgery, Vol. 175 (1998) pp. 494-496. 
     Nevertheless, clipping may lead to irregularities at the junction of the anastomosed vessels. In addition, it has been reported that “both periadventitial tissue stripping and microvascular clip application have deleterious effects in the early postoperative period” and that “temporary clips with a lesser width must be used in place of microvascular clips” while performing microvascular anastomosis. S. Keskil, N. Ceviker, K. Baykaner,. Uluo{haeck over (g)}lu and Z. S. Ercan, Early Phase Alterations in Endothelium Dependent Vasorelaxation Responses Due to Aneurysm Clip Application and Related Manipulations, Acta Neurochirurgica, Vol. 139(1) (1997) pp. 71-76. 
     2.2.2. Coupling 
     Tissue bonding by coupling with the aid of devices such as stents, ferrules, or rings without staples is considered to be older than stapling. Among the more recent devices and techniques, U.S. Pat. No. 4,523,592 discloses anastomotic coupling means capable of end-to-end and end-to-side anastomosis without resorting to suturing. The vessels are coupled with a pair of coupling disc members that cooperatively lock and secure the everted tissue from the anastomosed structures. These everted tissues remain in intima-intima contact with no foreign material exposed to the lumen of the anastomosed vessels. U.S. Pat. Nos. 4,607,637, 4,917,090 and 4,917,091 also disclose the use of anastomosis rings and an instrument for joining vessels or tubular organs which are threaded to the annular devices before the joining. The instrument and the anastomosis rings are shaped and adapted to be utilized mainly in microsurgery. U.S. Pat. Nos. 4,657,019 and 4,917,087 disclose devices, kits and methods for non-suture end-to-end and end-to-side anastomosis of tubular tissue members that employ tubular connection members and provide intima-intima contact at the anastomosis site with no foreign material exposed to the lumen of the vessels being joined. An annuli pair that provides an anastomotic clamp and that is especially adapted for intraluminal disposition is disclosed in U.S. Pat. No. 5,336,233. Because of the intraluminal disposition, this device is exposed to the blood flow in the anastomosed vessels. U.S. Pat. No. 4,907,591 discloses a surgical instrument for use in the installation of an assembly of interlocking coupling members to achieve compression anastomosis of tubular structures. Other coupling devices include the use of intraluminal soluble stents and extraluminal glues, such as cyanoacrylates, for creating nonsuture anastomoses. Reportedly, 98% patency was obtained with these soluble polyvinyl alcohol stents. Review of Facilitated Approaches to Vascular Anastomosis, pp. S124-S125. An absorbable anastomotic device for microvascular surgery relies on the cuffing principle with injection-molding techniques using the polymer polyglactin. Vessel ends that are everted 180.degree. are joined in this technique by an interconnecting collar so that an intima-intima seal is achieved. Reportedly, 96% patency was obtained with these absorbable interconnecting collars. Review of Facilitated Approaches to Vascular Anastomosis, p. S125. 
     The major advantage of a coupling microvascular anastomotic device has been reported to be the reduction in the time needed for a venous anastomosis, which decreases the total ischemic time. Maisie L. Shindo, Peter D. Constantino, Vincent P. Nalbone, Dale H. Rice and Uttam K. Sinha, Use of a Mechanical Microvascular Anastomotic Device in Head and Neck Free Tissue Transfer, Archives of Otolaryngology—Head &amp; Neck Surgery, Vol. 122(5) (1996) pp. 529-532. Although a number of coupling techniques do not place any foreign body in the intraluminal space of the anastomosed vessels, it is considered that the use of a foreign rigid body such as a ring that encloses a dynamically dilating structure is a disadvantage of this type of technique. Furthermore, this type of technique is viewed as not being flexible enough for its application to significant vessel size discrepancies in end-to-side anastomosis, and the devices are characterized as being of limited availability and needed in sets of different sizes. Microscopic Analysis of Stapled Microvascular Anastomosis, p. S 128. In addition, most coupling techniques require considerable eversion, incisions and mounting of the coupling devices that are difficult or impossible to apply endoscopically. 
     2.2.3. Adhesives 
     Pasting by applying adhesives or glues is widely employed in medicine. Several glues have been tested in anastomotic procedures, including fibrin glue, cyanoacrylic glues and photopolymerizable glues. 
     Fibrin glue is a biological two-component sealant comprising fibrinogen solution and thrombin combined with calcium chloride solution. These components are typically available deep-frozen in preloaded syringes, and they are mixed during application after thawing. Commercially available fibrin glue Tissucol has reportedly been approved by the Food and Drug Administration for use in the United States. See, Thomas Menovsky and Joost de Vries, Use of Fibrin Glue to Protect Tissue During CO 22  Laser Surgery, Laryngoscope Vol. 108 (1998) pp. 1390-1393. This article will hereinafter be referred to as “Fibrin Glue in Laser Surgery.” 
     The use of fibrin glue has been found to be practical in telescoping anastomoses and in microanastomoses. Satoru Saitoh and Yukio Nakatsuchi, Telescoping and Glue Technique in Vein Grafts for Arterial Defects, Plastic and Reconstructive Surgery, Vol. 96(6) (1995) pp. 1401-1408; Seung-Kyu Han, Sung-Wook Kim and Woo-Kyung Kim, Microvascular Anastomosis With Minimal Suture and Fibrin Glue: Experimental and Clinical Study, Microsurgery, Vol. 18(5) (1998) pp. 306-311. In contrast, it has been reported that the application of thrombin-based fibrin sealant (fibrin glue) to microvascular anastomoses can have noticeable deleterious effects, particularly when used in venous anastomosis. Christopher A. Marek, Lester R. Amiss, Raymond F. Morgan, William D. Spotnitz and David B. Drake, Acute Thrombogenic Effects of Fibrin Sealant on Microvascular Anastomoses in a Rat Model, Annals of Plastic Surgery, Vol. 41(4) (1998) pp. 415-419. 
     A biological procoagulant solution has been described as promising. The mixture contains bovine microfibrillar collagen and thrombin. Gary Gershony, John M. Brock and Jerry S. Powell, Novel Vascular Sealing Device for Closure of Percutaneous Vascular Access Sites, Catheterization and Cardiovascular Diagnosis, Vol. 45(1) (1998) pp. 82-88; Ted Feldman, Percutaneous vascular Closure: Plugs, Stitches, and Glue, Catheterization and Cardiovascular Diagnosis, Vol. 45(1) (1998) p. 89; Zoltan G. Turi, Plugging the Artery With a Suspension: A Cautious Appraisal, Catheterization and Cardiovascular Diagnosis, Vol. 45(1) (1998) pp. 90-91. 
     Cyanoacrylic glues tested on vessels include methyl cyanoacrylate and butyl cyanoacrylate, such as Histoacryl glue (butyl-2-cyanoacrylate). The ultra-violet polymerizable glue polyethyleneglycol 400 diacrylate has also been tested and reported that it “is able to effectively seal vessel puncture sites and anastomotic junctions without acutely augmenting local vascular thrombogenicity.” G. A. Dumanian, W. Dascombe, C. Hong, K. Labadie, K. Garrett, A. S. Sawhney, C. P. Pathak, J. A. Hubbell and P. C. Johnson, A new Photopolymerizable Blood Vessel Glue That Seals Human Vessel Anastomoses Without Augmenting Thrombogenicity, Plastic and Reconstructive Surgery, Vol. 95(5) (1995) pp. 901-907. 
     Glues used in anastomotic practice face the challenges inherent to factors that include toxicity, thrombogenicity, vascular wall thinning, and mechanical strength of the joint. Review of Facilitated Approaches to Vascular Anastomosis, p. S125; Henk Giele, Histoacryl Glue as a Hemostatic Agent in Microvascular Anastomoses, Plastic and Reconstructive Surgery, Vol. 94(6) (1994) p. 897. 
     2.2.4. Lasers 
     Lasers have been used in angioplastic revascularization since about 1984. See for example, Markolf H. Niemz, Laser Tissue Interactions, pp. 216-221, Springer Verlag 1996, (this work will hereinafter be referred to as “Laser Tissue Interactions”); R. Viligiardi, V. Gallucci, R. Pini, R. Salimbeni and S. Gahberti, Excimer Laser Angioplasty in Human Artery Disease, in Laser Systems in Photobiology and Photomedicine, edited by A. N. Chester, S. Martellucci and A. M. Scheggi, pp. 69-72, Plenum Press, New York, 1991; Timothy A. Sanborn, Laser Angioplasty, in Vascular Medicine, edited by Joseph Loscalzo, Mark A. Creager and Victor Brounwald, pp. 771-787, Little Brown Co. Whereas balloon angioplasty typically fractures, compresses or displaces plaque material, laser angioplasty typically removes plaque material by vaporizing it. Lawrence I. Deckelbaum, Cardiovascular Applications of Laser Technology, in Laser Surgery and Medicine, edited by Carmen A. Puliafito, pp. 1-27, Wiley-Liss, 1996. 
     The refinement of anastomosis techniques that rely on laser has been progressing since the reportedly first use of a neodymium yttrium-aluminum-garnet laser (“Nd-YAG laser”) on vascular anastomosis in 1979. Particularly in an end-to-side vascular anastomosis, the end of a graft in the form of a tubular structure is connected to the side wall of a receiving vessel so that the anastomosed end of the graft encompasses the anastomosis fenestra, or artificial window, that has been formed into the side wall of the receiving vessel. Consequently, lasers can be used in anastomoses for welding the anastomosed structures and/or for opening the anastomosis fenestra. In addition to YAG lasers, such as Nd-YAG and Ho-YAG lasers, Excimer, diode, CO 2  and argon lasers have also been used in vascular anastomoses. 
     Laser welding has been defined as the process of using laser energy to join or bond tissues. Typically, laser welding relies on photothermal effects, but efforts are being made to develop laser welding that relies on photochemical effects, where the laser radiation activates cross-liking agents that are expected to produce stronger links than those produced by photothermal welding. Lawrence S. Bass and Michael R. Treat, Laser Tissue Welding: A Comprehensive Review of Current and Future Clinical Applications, in Laser Surgery and Medicine, edited by Carmen A. Puliafito, pp. 381-415. (This work will hereinafter be referred to as “Laser Tissue Welding”). 
     Generally, the use of lasers in anastomotic practice faces the challenges inherent to factors that include the cost of laser purchase, maintenance and training, radiation damage to surrounding tissue, aneurism formation, the need for about three or four sutures (versus the nine or ten sutures applied in conventional anastomosis), side effects of heat-induced tissue welding, and mechanical failure at the anastomosis site. Review of Facilitated Approaches to Vascular Anastomosis, pp. S125-S126; Laser Tissue Welding, pp. 407-410; Brian C. Cooley, Heat-induced Tissue Fusion For Microvascular Anastomosis, Microsurgery, Vol 17(4) (1996) pp. 198-208. It has been reported, however, that the “nonocclusive Excimer laser-assisted anastomosis technique is safe and yields a high longterm patency rate in neurosurgical patients” and that there might be indications for this method in coronary bypass surgery. Cornelis A. F. Tulleken, Rudolf M. Verdaasdonk, and Hendricus J. Mansvelt Beck, Nonocclusive Excimer Laser-Assisted End-to-Side Anastomosis, Annals of Thoracic Surgery, Vol. 63 (1997) pp. S138-S142. (This article will hereinafter be referred to as “Nonocclusive Excimer Laser-Assisted End-to-Side Anastomosis”). In addition, laser anastomosis is considered to offer moderately reduced operative time, reduced skill requirements, faster healing, ability to grow, and possibly reduced intimal hyperplasia. Laser Tissue Welding, pp. 407-410 (further reporting on selected microvascular anastomosis studies with lasers that include CO 2 , argon, and diode lasers). Furthermore, research is being done to replace some of the initial laser sources by other lasers that are believed to be more suitable for clinical applications. For example, recent work with the 980 nm diode laser indicates that it may “replace in the near future laser sources of older conception such as the Nd-YAG.” W. Cecchetti, S. Guazzieri, A. Tasca and S. Martellucci, 980 nm High Power Diode Laser in Surgical Applications, in Biomedical Optical Instrumentation and Laser-Assisted Biotechnology, edited by A. M. Verga Scheggi, S. Martellucci, A. N. Chester and R. Pratesi, pp. 227-230, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1996. 
     The CO 2  laser can seal blood vessels, including small blood vessels of about 0.5 mm in diameter or less and it has been used in microvascular anastomosis such as in human lympho-venous anastomosis. D. C. Dumitras and D. C. A. Dutu, Surgical Properties and Applications of Sealed-off CO 2  Lasers, in Biomedical Optical Instrumentation and Laser-Assisted Biotechnology, edited by A. M. Verga Scheggi, S. Martellucci, A. N. Chester and R. Pratesi, pp. 231-239, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1996. In addition to the CO 2  laser which is an efficient vaporizer of tissue, other lasers that effectively vaporize tissue include the argon and the KTP/532 lasers. Lasers—Invention to Application, p. 106. 
     The argon laser has been reported to offer advantages over conventional end-to-end anastomosis procedures applied to growing vessels. Eiji Chikamatsu, Tsunehisa Sakurai, Naomichi Nishikimi, Takashi Yano and Yuji Nimura, Comparison of Laser Vascular Welding, Interrupted Sutures, and Continuous Sutures in Growing Vascular Anastomoses, Lasers in Surgery and Medicine, Vol. 16(1) (1995) pp. 34-40. It has also been reported that low temperature argon laser welding limits anastomotic thrombogenicity, which is thought of as a factor that may improve early patency of venous and small arterial bypass grafts. Steven B. Self, Douglas A. Coe and James M. Seeger, Limited Thrombogenicity of Low Temperature Laser-Welded Vascular Anastomoses, Lasers in Surgery and Medicine, Vol. 18(3) (1996) pp. 241-247. 
     The use of laser for medical purposes requires safety measures for protecting health care practitioners who handle the laser device and for shielding surrounding tissues and avoiding unintended radiation induced damage. Laser shield materials include layers of polymethylmethacrylate and tinfoil. See, Christine C. Nelson, Krystyna A. Pasyk and Gregory L. Dootz, Eye Shield for Patients Undergoing Laser Treatment, American Journal of Opthalmology Vol. 110 (1990) pp. 39-43. Laser shield materials are known and they have been disclosed in a variety of sources such as Alex Mallow and Leon Chabot, Laser Safety Handbook, Van Nostrand Reinhold Co., New York (1978), and A. Roy Henderson, A Guide to Laser Safety, Chapman &amp; Hall, London (1997). In particular, for example, the biological sealant fibrin glue can prevent severe damage to tissue when accidentally exposed to CO 2  laser radiation and intraoperative coating with fibrin glue can serve as a shield to protect arteries, veins, and nerves from accidental CO 2  laser exposure. Furthermore, it is considered that the use of fibrin glue for laser radiation protective processes “is especially attractive in . . . fields in which the glue is already used for sealing.” Fibrin Glue in Laser Surgery at p. 1393. 
     2.2.5. Other Devices and Techniques 
     It is known that some anastomosis techniques combine different approaches. For example, biological glues that are based on proteins and other compounds are combined with laser radiation in laser soldering. “Laser soldering is a bonding technique in which a proteinaceous solder material is applied to the surfaces to be joined followed by application of laser light to seal the solder to the tissue surfaces.” Laser Tissue Welding, pp. 389-392. Egg albumin, heterologous fibrin glue, and human albumin have been used as laser solders, also known as adjuvant materials for laser tissue welding. Dix P. Poppas, Theodore J. Choma, Christopher T. Rooke, Scott D. Klioze and Steven M. Schlossberg, Preparation of Human Albumin Solder for Laser Tissue Welding, Lasers in Surgery and Medicine, Vol. 13(5) (1993) pp. 577-580. 
     In an even newer technique, a chromophore is added to the solder to achieve photoenhancement effects that lead to an enhanced light absorption in the solder and not in the nontargeted tissue. Id., p. 391. In laser sealing, also known as laser-activated tissue sealing, sutured or stapled repairs are reinforced with laser solder, which is expected to provide “the strength and security of sutures and the watertightness of solder.” Id., pp. 403-404. 
     The graft in a vascular anastomosis does not necessarily have to be an autologous blood vessel. In addition to ePTFE tubular grafts that have been referred to in a preceding subsection, several synthetic materials for vascular grafts have been used or are being developed. 
     Synthetic biomaterials that are being developed include polymeric materials with the proteins elastin and fibronectin. A. Maureen Rouhi, Contemporary Biomaterials, Chemical &amp; Engineering News, Vol. 77(3) (1999) pp. 51-63. 
     ePTFE has been used with a variety of coatings. One type of coating includes fibrin glue that contains fibroblast growth factor type 1 and heparin. John L. Gray, Steven S. Kang, Gregory C. Zenni, Dae Un Kin, Petre I. Kim, Wilson H. Burgess, William Drohan, Jeffrey A. Winkels, Christian C. Haudenschild and Howard P. Greisler, FGF-1 Affixation Stimulates ePTFE Endothelialization without Intimal Hyperplasia, Journal of Surgical Research, Vol. 57(5) (1994) pp. 596-612; Joseph I. Zarge, Vicki Husak, Peter Huang and Howard P. Greisler, Fibrin Glue Containing Fibroblast Growth Factor Type 1 and Heparin Decreases Platelet Deposition, The American Journal of Surgery, Vol. 174(2) (1997) pp. 188-192; Howard P. Greisler, Claire Gosseli, Dewei Ren, Steven S. Kang and Dae Un Kin, Biointeractive Polymers and Tissue Engineered Blood Vessels, Biomaterials, Vol. 17(3) (1996) pp. 329-336. Another coating contains basic fibroblast growth factor in fibrin glue. M. Lanzetta, D. M. Crowe and M. J. Hickey, Fibroblast Growth Factor Pretreatment of 1-mm PTFE Grafts, Microsurgery, Vol. 17(11) (1996) pp. 606-611. 
     Other grafts comprise a synthetic biodegradable tubular scaffold, such as a vessel made of polyglactin/polyglycolic acid, that has been coated with autologous cells from a tissue culture. Toshiharu Shinoka, Dominique Shum-Tim, Peter X. Ma, Ronn E. Tanel, Noritaka Isogai, Robert Langer, Joseph P. Vacanti and John E. Mayer, Jr., Creation of Viable Pulmonary Artery Autografts Through Tissue Engineering, The Journal of Thoracic and Cardiovascular Surgery, Vol. 115(3) (1998) pp. 536-546. 
     A common feature of most conventional stapling, coupling and clipping techniques, particularly when applied to small-diameter vessels, is that they require a temporary interruption of the blood stream in the recipient vessel, a disruption that is thought to be not very well tolerated in cardiac bypass surgery. Review of Facilitated Approaches to Vascular Anastomosis, p. S126. In revascularization procedures of the brain, temporary occlusion of a proximal brain artery may cause brain ischemia, and consequently a nonocclusive anastomosis technique is required. Nonocclusive Excimer Laser-Assisted End-to-Side Anastomosis, p. 141. As the instrumentation that is needed at the anastomosis site becomes complex and cumbersome, a wider open area is needed for accessing the anastomosis site, thus leading to an increasingly invasive procedure. Furthermore, conventional anastomosis techniques are usually performed at a site that is determined by external observation of the affected area. This observation is performed at a time and in a medical setup that are different from the time and medical setup of a previous exploratory or diagnosis procedure. 
     Techniques that require the perforation of blood vessel tissue have raised concerns regarding intimal injury, adventitial stripping, tissue plane malalignment, and anastomotic bleeding. In addition, techniques that rely on devices that are exposed to the blood flow may lead to technical problems associated with a persistent intraluminal foreign body. These factors are thought to “contribute to both early and late anastomotic failure, particularly in the form of neointimal hyperplasia.” Nonpenetrating Clips for Coronary Anastomosis, p. S135. 
     The need for completely endoscopic anastomosis procedures has been clearly expressed in the context of coronary artery bypass grafting. For example, it is currently acknowledged that “the goal of a completely endoscopic coronary artery bypass procedure has not yet been realized, and will require further technological advances.” Endoscopic Coronary Artery Bypass Grafting, p. 1064. Furthermore, totally endoscopic coronary artery bypass grafting “is perceived by many as the ultimate surgical model of minimally invasive coronary artery bypass grafting”. Hani Shennib, Amr Bastawisy, Michael J. Mack, and Frederic H. Moll, Computer-Assisted Telemanipulation: An Enabling Technology for Endoscopic Coronary Artery Bypass, Annals of Thoracic Surgery, Vol. 66 (1998) p. 1060. 
     Minimally invasive vascular grafting according to a peripheral procedure is equally desirable, and minimally invasive active endoscopic or peripheral methods, systems and devices are specially desirable. In addition, methods, systems and devices that can be used in catheter directed as well as in non-catheter directed vascular anastomosis are particularly desirable because sometimes an occluded or damaged vessel does not permit catheterization from a point that is too far from the anastomosis site. 
     These methods, systems and apparatuses are specially desirable when, in particular, they are versatile enough as to be able to incorporate a plurality of the desirable features that have been discussed hereinabove while reviewing different groups of vascular anastomosis techniques. This desirability is consistent with the reported expectation that reliable methods for facilitated anastomosing of vessels will be developed by combining the best features of a variety of techniques. Review of Facilitated Approaches to Vascular Anastomosis, p. S126. 
     Each one of the afore-mentioned patents and publications is hereby incorporated by reference in its entirety for the material disclosed therein. 
     OBJECTS AND BRIEF SUMMARY OF THE INVENTION 
     Conventional anastomosis techniques do not rely on intraluminally directed anastomosis procedure. It is therefore desirable to provide methods, systems and devices for achieving intraluminally directed anastomosis. 
     An object of the present invention is to provide apparatus, methods, systems for performing an anastomosis through use of an intraluminally directed anvil apparatus or alternatively an externally positioned anvil apparatus. 
     Another object of this invention is to provide systems and apparatus that work in conjunction with an intraluminally directed anvil apparatus to anastomose vessels together. 
     Additionally, another object of this invention is to provide methods, systems, and devices for joining vessels together in a secure manner such that the portions defining the openings of the vessels are not penetrated. 
     Additionally, another object of this invention is to provide methods, systems, and devices for joining vessels together through the use of plates that are guided to each other by guides. 
     Still another object of the present invention is to provide methods, systems, and devices that are versatile enough to be able to suitably combine a variety of cutting, welding, and joining techniques in the practice of vascular anastomosis. 
     A feature of this invention is that the anvil apparatus can be positioned in a vessel intraluminally such that an anvil abuts the wall of the vessel with an anvil pull extending through an initial piercing in the vessel wall. This is preferably achieved through the use of a catheter inserted into and along the intraluminal space of a receiving blood vessel. Because the initial piercing is too small for the anvil to pass through, the anvil pull can be pulled in a manner that causes the wall of the vessel to be distended. 
     The opening is formed in a manner that consistently creates a complete cut having a perimeter with a desired shape such as a circle or an ellipse depending on the type of anastomosis. The precision of the cutting is due to several features. As mentioned above, the vessel wall is distended over the anvil which enables the wall to be stretched. This assists in creating a clean cut. The anvil is larger than the cutter so that the cut is formed due to the pressure between anvil and the cutter instead of forcing the vessel between the cutter and the anvil. Also, the anvil is preferably configured such that it has an engaging end that is convex and is more preferably spherical so that when engaged by a cylindrical cutter the cutter can self center on the engaging end. The cutter is also preferably spring biased which provides increased pressure for engaging the anvil. 
     The ability to distend the vessel wall is particularly useful when a compression plate apparatus is utilized to join the vessels. This compression plate apparatus includes two opposing and generally annular compression plates in a generally coaxial orientation. The end of the graft vessel that is to be anastomosed is everted onto one of the compression plates. The anvil pull is used to distend the receiving vessel wall such that it extends into compression plate apparatus. With the other compression plate placed at and around the anastomosis site, an anastomosis fenestra is opened in the wall of the receiving vessel. This anastomosis fenestra is opened within the annular region generally defined by the compression plate located at and around the anastomosis site. With the aid of the anvil of this invention, the contour of the anastomosed fenestra is engaged with the compression plate which opposes the compression plate that carries the graft vessel. This engagement is preferably accomplished with the aid of holding tabs protruding from the compression plate placed around the anastomosis fenestra. The degree to which the anvil has distended the receiving vessel before formation of the fenestra determines the size of the portion defining the vessel opening that remains in the compression plate apparatus. By adequately distending the receiving vessel wall, the portion defining the opening can be captured by the compression plate apparatus and everted. The graft vessel is subsequently approached to the anastomosis fenestra by reducing the separation between the compression plates, so that the graft vessel causes the eversion of the contour of the anastomosis fenestra by appropriately sliding on the surface of the anvil. Once the portion of the vessel that defines the opening has been everted then the compression plate apparatus can be compressed in a manner such that the everted portion of the receiving vessel is held against the everted portion of the other vessel such as a graft vessel. The relative separation of the compression plates is reduced to the extent necessary to bring the everted edges of the anastomosed structures into contact engagement so that a leak proof anastomosis is achieved. 
     A feature of the present invention is that the compression plate apparatus is suitable for end-to-side anastomosis in addition to side-to-side anastomosis. Furthermore, the compression plate apparatus of this invention provides support to the anastomosed structures in a manner such that the compression plates do not disrupt the periodic dilation of the anastomosed structures as is required by the characteristics of the blood flow that circulates therethrough. Moreover, the compression plate apparatus of this invention is used, together with the anvil, to evert the contour of the anastomosed fenestra in the receiving vessel while the anastomosis takes place. In addition, the compression plate apparatus of this invention can be used in conjunction with an anvil and anvil pull, regardless of whether the vascular anvil and wire are introduced into the receiving blood vessel with the aid of a catheter or directly into the intraluminal space through a small incision at the anastomosis site. 
     Another feature of the present invention is that the anvil is configured in a way such that it cooperates with the cutting element in the opening of the anastomosis fenestra and it also cooperates with the compression plate apparatus in the eversion of the edge of the anastomosed fenestra. By joining the everted contour of the anastomosis fenestra with the everted edge of the graft vessel, significant exposure to the blood flow of the cut portion of the anastomosed structures is avoided. Furthermore, the use of the anvil in a plurality of operations permits a considerable simplification of the anastomosis procedure. These operations include the abutting of the receiving blood vessel wall at the anastomosis site, the opening of the anastomosis fenestra in the receiving blood vessel, the eversion of edge of the anastomosis fenestra, and the joining of the anastomosed structures. 
     As discussed in more detail hereinbelow, the opening of the anastomosis fenestra can be performed mechanically or with the aid of a radiation-based device. The graft vessel is joined to the wall of the receiving blood vessel by a compression plate device. This device is configured in a manner such that it permits the use of supplementing joining techniques and combinations thereof. These techniques include welding, soldering, and gluing. Moreover, the signaling of the anastomosis site is preferably performed with the aid of a mechanical device such as the combination of a wire and an anvil. 
     The compression plate apparatus may be two opposing plates that are guided to each other as they are compressed together by guides which ensure that the plates maintain a parallel orientation with respect to each other. The compression plate apparatus may also be a snap-fit apparatus which ensures that the vessels are held together without penetrating the portions of the vessels that define the openings. 
     Many of the features obtained through the use of an intraluminally directed anvil apparatus can also be utilized in conjunction with an externally positioned anvil apparatus. For example, the advantageous cutting properties achieved with an intraluminally positioned anvil apparatus engaging a cutter as described above can also be used by an anvil apparatus that has been positioned within the lumen of a vessel by inserting the anvil through an insertion opening in the vessel. 
     An external anastomosis operator is also provided that controls the anastomosis procedure once the anvil pull extends out of the wall of the vessel and can be engaged. The external anastomosis operator enables the anastomosis procedure to mechanized so that it is rapidly and reliably completed in a highly controlled manner. The external anastomosis operator can also be utilized with an anvil apparatus that has been positioned externally into a vessel as well as the compression plates. 
     One advantage of performing a minimally invasive anastomosis under the active endoscopic or peripheral procedure that is based on the methods, systems, and devices of the present invention is that its practice does not require the training in surgical methods and techniques that the practice of surgery requires. Cross-specialty teams of practitioners including those with training in endovascular intervention as well as conventional surgical training can consequently perform minimally invasive anastomoses according to the methods, apparatuses, and systems of this invention. 
     Another feature of the active endoscopic or peripheral procedure of this invention is that it directly employs information while it is being acquired in an angiographic examination. This efficient use of information, and in particular imaging, has the advantage that the anastomosis is actually performed in less time and without having to rely on the correlation of previously recorded images with external anatomic inspection for locating the optimal anastomosis site. The shorter procedure according to this invention consequently requires less or no hospitalization time and less medical resources. 
     Still another feature of the active endoscopic or peripheral procedure of this invention is that it requires no sutures. The avoidance of sutures has the advantages of reducing the invasive character of the procedure, reducing the number of mechanical elements in the practice of the anastomosis, and shortening the time needed to perform the anastomosis. 
     By not requiring the interruption of blood flow in the receiving blood vessel, the active endoscopic or peripheral procedure of this invention advantageously reduces or even eliminates the risk of ischemia in organs that receive their main supply of blood through the receiving blood vessel. Furthermore, the exposure of the anastomosis area is reduced because no devices have to be introduced to temporarily interrupt blood flow. This feature advantageously enhances the minimally invasive character of the methods, systems, and apparatuses of this invention and the intervention time for the practice of the anastomosis. 
     The minimal disruption of blood flow in the receiving blood vessel by the active endoscopic or peripheral procedure of this invention advantageously makes it suitable in the context of coronary artery bypass grafting (CABG), whether blood circulation is intracorporeal or extracorporeal, and whether the grafting is performed on a beating heart or an arrested heart. 
     A feature of the catheter assisted endoscopic or peripheral procedure of this invention is the versatility of the vascular anvil and wire for signaling the anastomosis site and of the extravascular device and cooperatively performing the anastomosis. Accordingly, a variety of devices and techniques can be advantageously combined in the context of this invention to enhance the performance of its methods, systems and devices. 
     These and other objects, features, and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG. 1  is a perspective view of a patient receiving a catheter at a catheterization site as a guide wire is directed to a remote anastomosis site. 
         FIG. 2A  is an enlarged partial cross-sectional view of a vessel with the coil of a guide wire positioned at the selected anastomosis site. 
         FIG. 2B  is an enlarged partial cross-sectional view of the vessel shown in  FIG. 2A  depicting the next phase of utilizing the catheter system after a positioning catheter is positioned at the anastomosis site. 
         FIG. 2C  is an enlarged partial cross-sectional view of the vessel shown in  FIG. 2B  depicting the next phase of utilizing the catheter system as the penetration catheter and the penetration wire extending through an initial piercing at the anastomosis site. 
         FIG. 2D  is an enlarged partial cross-sectional view of the vessel shown in  FIG. 2C  depicting the next phase of utilizing the catheter system after the penetration wire has been removed so that only the penetration catheter remains. 
         FIG. 2E  is an enlarged partial cross-sectional view of the vessel shown in  FIG. 2D  depicting the next phase of utilizing the catheter system as an anvil pull of an intraluminally directed anvil apparatus is inserted through the penetration catheter. 
         FIG. 2F  is an enlarged partial cross-sectional view of the vessel shown in  FIG. 2E  after the anvil pull of an intraluminally directed anvil apparatus has been pulled through the wall of the vessel  20  so that the anvil is brought into contact with the interior of the vessel. 
         FIG. 3A  is a perspective view of a guided compression plate apparatus with phantom lines to show the compressed position. 
         FIG. 3B  is a perspective view of the guided compression plate apparatus shown in  FIG. 3A  with a graft vessel loaded onto the holding tabs of the second compression plate and a cutter positioned to be loaded into the lumen of the graft vessel. 
         FIG. 4A  is a cross-sectional view of the compression plate apparatus shown in  FIG. 3A  as anvil apparatus distends a blood vessel into the compression plate apparatus. 
         FIG. 4B  is a cross-sectional view of the compression plate apparatus shown in  FIG. 4A  in the next phase as a cutter and an anvil are engaged to form an opening in the vessel. 
         FIG. 4C  is a cross-sectional view of the compression plate apparatus shown in  FIG. 4B  in the next phase after the second compression plate has been compressed towards the first compression plate such that the everted graft vessel contacts the everted blood vessel. 
         FIG. 4D  is a cross-sectional view of the compression plate apparatus shown in  FIG. 4C  with the anastomosed structure after the anvil apparatus and the cutter have been removed. 
         FIG. 5A  is a perspective view of the guided compression plate apparatus shown in  FIG. 3A  with a graft vessel loaded onto the holding tabs of the second compression plate, a cutter positioned in the lumen of the graft vessel and an adapter ready to be positioned on the second compression plate. 
         FIG. 5B  is a perspective view of the guided compression plate apparatus shown in  FIG. 3A  with a graft vessel loaded onto the holding tabs of the second compression plate, a cutter positioned in the lumen of the graft vessel and an adapter positioned on the second compression plate. 
         FIG. 6A  is a perspective view of an external anastomosis operator. 
         FIG. 6B  is an exploded perspective view of the external anastomosis operator. 
         FIG. 6C  is a cross-sectional view of the external anastomosis operator. 
         FIG. 6D  is a cross-sectional view of the external anastomosis operator as the anvil pull advancer knob is rotated to pull the anvil pull so that the anvil causes distension of the blood vessel into the compression plate apparatus. 
         FIG. 6E  is a cross-sectional view of the external anastomosis operator as the attachment actuator device is moved to compress the second compression plate against the first compression plate. 
         FIG. 7A  is a perspective view of an alternative embodiment of an anvil having a slightly tapered landing. 
         FIG. 7B  is a perspective view of an alternative embodiment of an anvil having a flared flange. 
         FIG. 7C  is a perspective view of an alternative embodiment of an anvil having a tapered terminal end. 
         FIG. 7D  is a perspective view of an alternative embodiment of an anvil having an elliptical engaging end and an eccentrically connected anvil pull. 
         FIG. 8  is an enlarged partial cross-sectional view of the vessel shown in  FIGS. 2A-2F  depicting an anvil pull of an intraluminally directed anvil apparatus pulled through the wall of the vessel  20  so that the anvil is brought into contact with the interior of the vessel after the apparatus has been positioned by a positioning stem extending from the anvil. 
         FIG. 9A  is a perspective view of a mechanically expandable anvil. 
         FIG. 9B  is a cross-sectional view of the anvil shown in  FIG. 9A . 
         FIG. 10A  is a perspective view of another mechanically expandable anvil. 
         FIG. 10B  is a cross-sectional view of the anvil shown in  FIG. 10A . 
         FIG. 11A  is a perspective view of a chemically expandable anvil. 
         FIG. 11B  is a cross-sectional view of the anvil shown in  FIG. 11A . 
         FIG. 12A  is a perspective view of a snap-fit compression plate apparatus. 
         FIG. 12B  is a perspective view of the snap-fit compression plate apparatus shown in  FIG. 12A  with a graft vessel loaded onto the holding surface of the second compression plate. 
         FIG. 12C  is a cross-sectional view of the compression plate apparatus shown in  FIG. 12B  as anvil apparatus distends a blood vessel into the compression plate apparatus. 
         FIG. 12D  is a cross-sectional view of the compression plate apparatus shown in  FIG. 12A  in the next phase as a cutter and an anvil are engaged to form an opening in the vessel. 
         FIG. 12E  is an enlarged partial cross-sectional view of the compression plate apparatus shown in  FIG. 12D  in the next phase as the graft vessel everts the portion of the blood vessel defining the first vessel opening. 
         FIG. 12F  is a cross-sectional view of the compression plate apparatus shown in  FIG. 12B  in the next phase after the second compression plate has been compressed towards the first compression plate such that the everted graft vessel contacts the everted blood vessel. 
         FIG. 12G  is a cross-sectional view of the compression plate apparatus shown in  FIG. 12C  with the anastomosed structure after the anvil apparatus and the cutter have been removed. 
         FIG. 13  is a perspective view of guided compression plate apparatus adapted for use in joining vessels at angles with elliptical openings with a graft vessel ready to be received through a cutter and loaded onto the holding tabs of the second compression plate. 
         FIG. 14A  is a perspective view of a cutter ready to engage an anvil with a thread anvil pull extending through the cutter to an anvil pull engager to form a circular opening. 
         FIG. 14B  is a perspective view of a cutter ready to engage an anvil with a thread anvil pull extending through the cutter to an anvil pull engager to form an elliptical opening. 
         FIG. 14C  is a perspective view of a clipping device applying clips to join two vessels in a nonperpendicular orientation. 
         FIG. 14D  is a cross-sectional view of the device capable cutting, delivering radiation for soldering, delivering adhesives and other fluids. 
         FIG. 15A  is a perspective and partial cross-sectional view of the compression plate apparatus shown in  FIG. 3A  being used in a side-to-side anastomosis while the first compression plate is held. 
         FIG. 15B  is a cross-sectional view of the compression plate apparatus shown in  FIG. 15A  in the next phase as a cutter and an anvil are engaged to form an opening in the vessel. 
         FIG. 15C  is a cross-sectional view of the compression plate apparatus shown in  FIG. 15B  in the next phase after the second compression plate has been compressed towards the first compression plate by an attachment actuation device such that the everted graft vessel contacts the everted blood vessel. 
         FIG. 16A  is a perspective view of the anvil from  FIG. 7C  being inserted from the exterior of a blood vessel into the blood vessel lumen. 
         FIG. 16B  is a perspective view of the blood vessel shown in  FIG. 16A  with the anvil depicted in phantom lines and a stay suture around the insertion opening. 
         FIG. 16C  is a perspective view of the external anastomosis operator cooperating with the anvil depicted in phantom lines to form an anastomosis. 
         FIG. 16D  is a cross-sectional view of the compression plate apparatus shown in  FIG. 3A  as the anvil apparatus distends a blood vessel having a stay suture around the insertion opening. 
         FIG. 16E  is a cross-sectional view of the compression plate apparatus shown in  FIG. 3A  as the anvil apparatus distends a blood vessel after being inserted into the lumen of the blood vessel through an insertion opening. 
         FIG. 17A  is a perspective view of an externally positioned anastomosis fenestra cutting apparatus inserting an anvil through an insertion opening into the lumen of a blood vessel. 
         FIG. 17B  is a perspective view of an externally positioned anastomosis fenestra cutting apparatus distending the vessel and being readied to cooperate with an anvil. 
         FIG. 17C  is a cross-sectional view and the anvil pull of the externally positioned anastomosis fenestra cutting apparatus shown in  FIGS. 17A-17B  pulling the anvil so that the engaging end of the anvil engages the cutter and forms an opening. 
         FIG. 18A  is a perspective view of an externally positioned anastomosis fenestra cutting apparatus cooperating with an elliptical anvil. 
         FIG. 18B  is a cross-sectional view and the anvil pull of the externally positioned anastomosis fenestra cutting apparatus shown in  FIG. 18A  pulling the anvil so that the engaging end of the anvil engages the cutter and forms an elliptical opening. 
         FIG. 19A  is a cross-sectional view of a spring biased externally positioned anastomosis fenestra cutting apparatus after the anvil has been inserted through an insertion opening. 
         FIG. 19B  is a cross-sectional view of the spring biased externally positioned anastomosis fenestra cutting apparatus shown in  FIG. 19A  as the anvil pull is pulled against the cutter. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention focuses on vascular anastomosis methods, systems, and devices as well as related technology for forming the openings that are subsequently anastomosed together. Numerous designs are disclosed herein for achieving the desired anastomosis. The following discussion focuses mainly on the use of an intraluminally directed anvil apparatus and an external anastomosis operator that work together with various anastomosis plate apparatus to join vessels together. However, some features of the intraluminally directed anvil apparatus can also be utilized with externally positioned anvil apparatuses that are inserted into a lumen through the wall of the lumen and are then utilized. Such externally positioned anvil apparatuses are also described. 
     Some of the main components that are utilized in accordance with the preferred methodology for intraluminally directed anastomosis procedures include a catheter system  100  and an intraluminally directed anvil apparatus  200 . The catheter system  100  is used to remotely position the intraluminally directed anvil apparatus  200  from a catheterization site to an anastomosis site. At the anastomosis site, additional main components are utilized with the intraluminally directed anvil apparatus  200  including a compression plate apparatus  300  and an external anastomosis operator  700 . The methodology for using these components is initially described in the context of joining an end of an attaching vessel to a side of a receiving vessel, however, the same methodology can be used with other anastomosis procedures such as side-to-side anastomosis as also described below. 
     This methodology is described in the subsection below that is entitled Methodology Overview. The main components are described in detail in the Methodology Overview including the catheter system  100 , the intraluminally directed anvil apparatus  200 , the compression plate apparatus  300  and the external anastomosis operator  700 . These components are also described and contrasted with other embodiments of these components in sections entitled Anvils, Compression plate apparatus, External Anastomosis Operators. 
     Additional methodologies for utilizing these components and alternative embodiments of these components are described in sections entitled Side-to-Side Anastomosis, Externally Directed Anastomosis, and Externally Positioned Anastomosis Fenestra Cutting Apparatus. 
     Methodology Overview 
     To optimally position intraluminally directed anvil apparatus  100 , catheter system  100  is utilized as shown in  FIG. 1  and  FIGS. 2A-2F .  FIG. 1  depicts a patient undergoing the initial step of a procedure utilized to remotely position the intraluminally directed anvil apparatus  200  at an anastomosis site  10  in a blood vessel  20  (not shown in  FIG. 1 ) in the chest or arm such as the brachial artery from a catheterization site  40  in a blood vessel in the patient&#39;s leg, the femoral artery. Catheter system  100  is shown in  FIG. 1  with an introducer  110  inserted at catheterization site  40  in the femoral artery. Introducer  110  permits a guide wire  120  to be inserted to the anastomosis site. Guide wire  120  preferably utilizes a coil  125  to minimize the potential of the guide wire  120  to cause damage. Guide wire  120  typically follows a fluoroscopic device, an endoscopic device or some other remote viewing instrumentation or imaging technique used to determine the location for the anastomosis site  10  such as the proximity of a blood vessel occlusion or another abnormality that has been detected by a conventional exploration technique. Any conventional guide wire suited for inserting both diagnostic and therapeutic catheters may be utilized such as those disclosed in U.S. Pat. No. 4,846,186, which is hereby incorporated by reference in its entirety, and catheters and guide wires for vascular and interventional radiology are disclosed in Catheters, Methods, and Injectors, at 155-174, which is also hereby incorporated by reference in its entirety. 
     Hub  115  is shows at the proximal end of guide wire  120  in  FIG. 1 . The proximal end of a catheter system such as catheter system  100  comprises one or a plurality of access ports or luer fittings such as hub  115 . For the purpose of simplicity, the proximal end of the various catheters depicted in  FIGS. 2A-2E  are not shown. However, the manufacture and handling of a catheter system with a plurality of lumens and a plurality of access ports are known to those of ordinary skill in the art. For example, U.S. Pat. Nos. 5,662,580 and 5,616,114, which have herein been incorporated by reference in their entirety, disclose catheters with a plurality of access ports or luer fittings and a plurality of lumens. 
       FIG. 2A  is an enlarged partial cross-sectional view of vessel  20  with coil  125  of guide wire  120  positioned at the selected anastomosis site  10 . Once guide wire  120  has been positioned at anastomosis site  10 , then a positioning catheter  140  and a straightening catheter  130  are pushed along guide wire  120  until they reach the anastomosis site  10 . Straightening catheter  130  has a tapered proximal end  135  that is adapted to minimize the impact of the positioning catheter  140  as they are advanced within a blood vessel. Once the straightening catheter  130  and positioning catheter  140  reach the anastomosis site  10 , then guide wire  120  can be removed as shown by the phantom lines in  FIG. 2A . Guide wire  120  is removed by pulling its distal end (not shown) that extends out of catheterization site  40  until guide wire coil  125  exits the catheterization site. 
       FIG. 2B  depicts the next phase of utilizing catheter system  100 . Positioning catheter  140  is designed to have an inherent curvature or curved memory at its distal end. In order to enable positioning catheter  140  to be moved as needed while moving through the patient&#39;s body to the anastomosis site, straightening catheter  130  extends within positioning catheter  130  in order to straighten positioning catheter  140 . Guide wire  120  also assists in providing resistance to the inclination of the distal end of the positioning catheter  130  to curve. Once anastomosis site  10  has been reached and the guide wire  120  has been removed, then catheter system  100  appears as shown in  FIG. 2A . The straightening catheter  130  is then withdrawn as shown in  FIG. 2B , to permit the distal end of the positioning catheter  140  to curve against the wall of blood vessel. An arrow is shown in  FIG. 2B  to indicate that a penetration catheter  150  containing a penetration wire  160  is inserted into straightening catheter  140 . The straightening catheter can be removed at this point as indicated by the arrow in  FIG. 2   b  or it can remain. 
       FIG. 2C  depicts penetration catheter  150  and penetration wire  160  extending through an initial piercing  15  at anastomosis site  10  through the wall of blood vessel  20 . Penetration wire  160  has a distal end  165  that is sharp and pointed to enable it to pierce through the blood vessel wall. Once the pointed distal end  165  of penetration wire  160  has pierced through the blood vessel wall then penetration catheter  150  can also be pushed or pulled through the blood vessel wall. 
       FIG. 2D  depicts catheter system  100  once positioning catheter  130  and straightening catheter  140  have been removed from around penetration catheter  150  and once penetration wire  160  has been removed from within penetration catheter  160 . At this point, penetration catheter  150  extends from catheterization site  40  (not shown in  FIG. 2D ) to anastomosis site  10  through the wall of blood vessel  20  at initial piercing  15 . Catheter system  100 , more particularly, penetration catheter  150  of catheter system  100  can then be used in association with the intraluminally directed anvil anastomosis apparatus  200 . 
       FIG. 2E  shows penetration catheter  150  with its proximal end in a partial broken view to indicate that the anvil pull  230  of the intraluminally directed anvil apparatus  200  has been inserted into penetration catheter  150  such that anvil pull  230  extends through penetration catheter  150  from the proximal end of penetration catheter  150  at the catheterization site  40 . Intraluminally directed anvil apparatus  200 , referred to in abbreviated form as an anvil apparatus, includes an anvil  210  having an engaging end  212  from which the anvil pull  230  extends. Once the distal end  232 , referred to herein as a penetration end of anvil pull  230 , extends beyond the distal end of penetration catheter  150 , then penetration end  232  alone or in combination with the distal end of penetration catheter  150  can be grasped so that the engaging end  212  of anvil  210  is brought into contact with the interior, specifically the intima, of the vessel. 
     As shown in  FIG. 2F , once the engaging end  212  of anvil  210  is brought into contact with the interior  22  of the wall of vessel  20  then penetration catheter  150  is removed. At this point, all components of catheter system  100  have been removed and only anvil  210  of anvil apparatus  200  remains in the lumen  28  of vessel  20 . 
     The length of anvil pull  230  and the length of the various elements of catheter system  100  are suitably chosen depending on the distance from the catheterization site to the anastomosis site. For example, this length would be approximately 180 cm long, depending on the patient&#39;s height, if an anastomosis were to be performed in a blood vessel in the arm such as the brachial artery, and catheter apparatus  100  were inserted into the femoral artery. 
     In another embodiment of an anvil apparatus  200 ′ described below in reference to  FIG. 9 , the anvil apparatus may be positioned through the use of a catheter system that comprises only a single catheter such as positioning catheter  140 . Since anvil apparatus  200 ′ is positioned at an anastomosis site by passing through a catheter such as positioning catheter  140 , it is necessary for the catheter to have dimensions that accommodate the diameter or width of the anvil to be inserted. In some of the experiments performed in the context of this invention, a catheter characterized as a 13 French sheath, also known as a 4.3 mm catheter—1 French unit=⅓ mm—, has been found suitable for most anvil apparatus insertions. Catheterization techniques are described, for example, by Constantin Cope and Stanley Baum, Catheters, Methods, and Injectors for Superselective Catheterization, in Abrams&#39; Angiography, edited by Stanley Baum, 4th ed., (this work will hereinafter be referred to as “Catheters, Methods, and Injectors”) which is hereby incorporated by reference in its entirety. However, as described above, it is preferable to utilize an anvil apparatus such as anvil apparatus  200  and to position the anvil against the wall of the blood vessel by pulling the anvil pull  230  after it has been inserted into a penetration catheter  160 . Penetration catheter need only be a 5 French sheath to receive the anvil pull  230  of most anvil apparatus. 
       FIG. 2F  shows that once anvil apparatus  200  has been positioned at anastomosis site  10  such that anvil pull  230  extends out of blood vessel  20  through initial piercing  15  in the wall of the first vessel then anvil pull  230  can be maneuvered to hold engaging end  212  of anvil  210  against interior  22  of the wall of blood vessel  22 . Note that since initial piercing  15  is so much smaller than engaging end  212  of anvil  210 , anvil  210  cannot pass through initial piercing  15 . This difference in size enables anvil  210  to be pulled against interior  22  in a manner such that the wall of vessel  20  can be distended. As discussed below, the ability to pull anvil pull  230  such that engaging end  212  of anvil  210  engages interior  22  and distends the wall of vessel  20  contributes significantly to the ability to evert the portions of the vessel wall around an opening or anastomosis fenestra used for attaching another vessel. Anvil  210  also has a cylindrical landing  214  which are its sidewall surfaces that assist in the eversion process as described below in reference to  FIGS. 4A-4D . 
     Anvil  210  and anvil pull  230  are preferably fixedly attached together. As shown, anvil pull  230  extends through anvil  210  via an anvil aperture  216  (not shown) and terminates at a stopping element  236 . Since the anvil pull is typically metal and the anvil is typically molded plastic, stopping element  236  may be just the proximal end of anvil pull  230  embedded in anvil  210  such that it is still visible. Of course, the proximal end may be embedded in a way such that it is not visible as shown in  FIG. 9B . In the embodiment shown in  FIG. 2F , the stopping element  236  is the proximal end of anvil pull  230  that has been bent so that it is partially embedded in terminal end  218  of anvil  210 . As described below, anvil  210  and anvil pull  230  may also be integral. Additionally, anvil  210  may be movably positioned on anvil pull  230  in which case, stopping element  23  can be used to brace against terminal end  218  of anvil  210 . 
     After the anvil  210  been positioned such that its engaging end  212  contacts the intima of vessel  20  with anvil pull  210  extending through the wall of vessel  20 , then anvil apparatus is ready to be utilized in an anastomosis procedure for joining vessel  20  with another vessel such as graft vessel  50  which may be any synthetic graft vessel such as ePTFE tubular grafts. Numerous approaches are disclosed herein for joining a portion of a first vessel that define a first vessel opening to a portion of a second vessel that defines a second vessel opening such that the first vessel and the second vessel are anastomosed together and are in fluid communication. A preferred approach involves the use of compression plates that provide for a desired degree of eversion of the vessels without requiring penetration of the vessels. An example of such compression plates is the guided compression plate apparatus shown in  FIG. 3A . Guided compression plate apparatus  300  is described in greater detail under the section titled Compression plate apparatus. 
     As can be seen from  FIG. 3B , a graft vessel  50  is loaded onto holding tabs  314   b  of compression plate  314  while a cutter  400  is positioned to be loaded into the lumen  58  of graft vessel  50 . Cutter  400  includes a cutting tube  410  that terminates at a cutting knife  412  with a cutting edge  414 . Note that a variety of cutters are disclosed herein as discussed in the section entitled Cutting Devices. Once cutter  400  is positioned within graft vessel  50  as shown in  FIG. 3C , then the combination of compression plate apparatus  300 , graft vessel  50  and cutter  400  are ready for use with anvil apparatus  200  to form an anastomosis. This combination is referred to herein as compression plate and cutter assembly  390  and is used much like a cartridge in the external anastomosis operator  700 . 
       FIGS. 4A-4D  depict the use of a compression plate apparatus  300  in combination with a cutter  400  and anvil  210  in the sequential order according to the preferred methodology. To optimally present this sequence,  FIGS. 4A-4D  are cross-sectional views.  FIG. 4A  depicts anvil  210  being pulled against the intima or interior of the vessel wall such that vessel  20  is sufficiently distended to permit the vessel  20  at anastomosis site  10  to be pulled into compression plate apparatus  300  through first compression plate opening  320   a . More particularly, anvil  210  is pulled by anvil pull  230  such that all of spherical engaging end  212  is pulled into the compression plate apparatus  300  and most of cylindrical landing  214 . Cutter  400  also is shown in  FIG. 4A  extending through second compression plate opening  320   b  about half way through compression plate apparatus  300  as cutter  400  is approximated with the portion of the blood vessel  20  distended by anvil  210 . 
       FIG. 4B  depicts the formation of a first vessel opening  24  in the wall of the first vessel. First vessel opening  24  is formed by pulling anvil pull  230  through cutter  400  sufficiently to enable anvil  210  to advance blood vessel  20  against cutting edge  414 . After the cut has been made then a cut portion  25  of the wall of blood vessel  20  remains on spherical engaging end  212  of anvil  210  while the portion  26  of the blood vessel that now define first vessel opening  24  rest on anvil landing  214 . As will be discussed in the Cutting Devices section and the External Anastomosis Operator section, cutter  400  is preferably spring biased. 
       FIG. 4C  depicts compression plate apparatus  300  after compression. More particularly, compression plate  310   b  has been moved toward compression plate  310   a  by sliding on guides  330  that extend from compression plate  310   a . Note that the everted portion  56  of graft vessel  50 , more particularly the portion  57  opposite from the rounded tip  316   b , is urged against portion  26  that defines first blood vessel opening  24  in a manner such that portion  26  has been everted. The end result is that the portion  27  opposite from rounded tip  316   a  is held in contact with the portion  57  of vessel  50  opposite from distal rounded tip  316   b.    
     As shown in  FIG. 4D , after compression plate apparatus  300  has been compressed to join portion  26  of blood vessel  20  that defines first vessel opening  24  to portion  56  of second vessel  50  that defines graft vessel opening  54  then first vessel  20  and second vessel  50  are anastomosed together and are in fluid communication. Anvil apparatus  200  and cutter  400  have been removed upon the completion of the procedure through lumen  58  of graft vessel  50 . More particularly, once the anastomosis is completed then anvil pull  230  is pulled so that it draws anvil  210  through openings  320   a  and  320   b  of compression plate apparatus  300  such that anvil apparatus  200  is removed along with cutter  400  through lumen  58 . Note that terminal ends  332  of guides  330  have been removed since they are no longer necessary. 
     Compression plate  310   b  does not slide on guides  330  after being compressed due to a frictional engagement. Several methods for achieving this frictional engagement are s described below in the Compression Plate Apparatus section below. Compression plate apparatus  300  utilizes a simplistic and yet effective frictional engagement as the guide apertures  334  in guide plate  310   b  are sized such that significant force is required to move plate  310   b  on guides  330 . 
     There are significant advantages to combining vessels in accordance with the methodology described above especially in a manner such that there is at least partial eversion, contact between the everted surfaces and no penetration of the portions of the vessels defining the vessel openings. Of course, the anastomosis is fluid tight to normal systolic pressure and remains intact under stress. Since the everted portions  26  and  56  respectively cover the holding tabs  314   a - b , no intraluminal foreign material is exposed and no subintimal connective tissue is intraluminally exposed. As a result, the thrombogenicity of the anastomoses is no greater than that of hand sutured anastomosis. Additionally, the configuration also results in an anastomosis that is morphologically satisfactory, including complete eversion of the receiving blood vessel intima with apposition to graft vessel. Further, everted portions  26  and  56 ′ are in intima-intima contact and no cut portion is significantly exposed to the blood flow that is to circulate through the anastomosed structures. 
     In addition to the results achieved, there are also significant procedural advantages. The method does not require temporary occlusion of blood flow to the target blood vessel. The anastomosis can be reliably created. Additionally, the anastomosis is rapidly achieved and eliminates the need for high skilled suturing. For example, once the anvil pull extends through the wall of the vessel, the anastomosis procedure can be accomplished in as little as 60 seconds when compression plates are used to join the vessels. 
     Manual manipulation may be utilized to achieve the steps shown in  FIGS. 4A-4D , however, mechanization is preferred. More particularly, anvil pull  230  may be manually pulled as cutter  400  is held or manually advanced. Additionally, compression plate apparatus may be manually compressed in some embodiments. Accordingly, components are not depicted in  FIGS. 4A-4D  for achieving these steps. However, as discussed in detail in the Compression Plate Apparatus section, Cutting Devices sections, and in the External Anastomosis Operator section, these steps are preferably achieved through the use of devices specifically adapted for these purposes. 
       FIGS. 5A-5B  depict the use of an optional second compression plate adaptor  610   b  in combination with compression plate and cutter assembly  390  as shown in  FIG. 3B  in preparation for use with the external anastomosis operator shown in  FIGS. 6A-6E  at  700 . The purpose of optional second compression plate adaptor  610   b  is described below in relation to the attachment actuation device  600 . Note that there is a cross-sectional view of compression plate and cutter assembly  390  and optional adaptor  610   b  in  FIG. 6C . 
       FIG. 6A  provides a perspective view of external anastomosis operator  700  with its main components identified including: cutter  400 , spring biasing device  450 , an anvil pull engager  500  which includes an anvil pull holder  530  and an anvil pull advancer  560 , and an attachment actuation device  600 . Spring biasing device  450  is used to apply pressure against the distal end  418  of cutter  400 . The advantages of using a spring biased cutter are explained below in the Cutting Devices section. Anvil pull  230  is fed through cutter  400 , through spring biasing device  450  and into an anvil pull holder  530 . An anvil pull holder  530  is preferably a clamp assembly adapted to hold anvil pull  230  extending from anvil  210  such that holder  530  is locked into position on anvil pull  230 . Anvil pull advancer  560  is adapted to pull anvil pull  230  once anvil pull  230  is held by holder  530 . As anvil pull advancer  560  pulls on anvil pull  230 , it causes anvil pull  230  to advance within compression plate assembly  300  and distend the wall of vessel  20  until cutter  400  is engaged. Anvil pull holder  530  and anvil pull advancer  560  are described in greater detail below in the External Anastomosis Operator section in reference to  FIGS. 6A-6E . 
     As shown in  FIG. 6C , the assembly depicted in  FIG. 5B  is inserted such that the first compression plate  310   a  is held via adaptor  610   a  and the second compression plate  310   b  is held via adaptor  610   b  while distal end  418  of cutter  400  abuts spring biasing device  450 . Anvil pull  230  is shown in  FIG. 6C  extending through cutter  400 . Cutter  400  is hollow so it has a chamber  420  between the sidewalls of cutting tube  410 . Cutter  400  may also have an optional centering core  422  that extends at least part way though chamber  420 . Centering core  422  has a centering conduit  424  that assists in centering anvil pull  230  in cutter  400  such that anvil pull  230  is essentially parallel with the sidewalls of cutting tube. As discussed below in greater detail, it is not always necessary for cutter  400  to have a centering core or for other cutters to have a centering core or a centering conduit. When the engaging end of the anvil is spherical and the cutter is spherical and is configured such that it permits part of the spherical engaging end of the anvil to be positioned in cutter chamber then the cutter self centers on the spherical engaging end. 
     As shown in  FIG. 6D , anvil pull  230  is inserted through cutter  400 , through spring biasing device  450  and into an anvil pull holder  530 . Holder knob  540  of anvil pull holder  530  is then rotated as described below to hold anvil pull  230 . Once anvil pull holder  230  securely holds anvil pull, then advancer knob  570  is rotated as shown in  FIG. 6D . Rotation of advancer knob  570  causes anvil pull holder  530  to pull on anvil pull  230 , which causes anvil pull  230  to advance within compression plate assembly  300  and distend the wall of vessel  20  until cutter  400  is engaged as depicted. Note that  FIG. 4B  depicts anvil  210  engaging cutter  400  at the same point in the process as is shown in  FIG. 6D  except  FIG. 4B  does not show any of the components of external anastomosis operator being used. 
       FIG. 6E  depicts attachment actuation device  600  being engaged. As explained above in reference to  FIGS. 4A-4D , once the anastomosis fenestra or vessel opening  24  has been made then compression plate assembly  300  can be compressed such that first and second compression plates  310   a - b  are brought together. As indicated above, compression plates  310   a - b  are preferably approximated through the use of appropriate devices. Attachment actuation device  600  achieves this purpose. Attachment actuation device  600  is also described in detail below in the External Anastomosis Operator section in reference to  FIGS. 6A-6E . However, to appreciate the advantages of the preferred methodology it should be understood that attachment actuation device  600  is used to bring the compression plates together in the manner depicted in  FIGS. 4A-4D . Attachment actuation device  600  has a first plate engager  600   a  and a second plate engager  600   b . These plate holders  600   a - b  may directly hold first and second compression plates  310   a - b  or optional adapters  610   a - b  may be utilized.  FIGS. 12C-12F  depict another embodiment of an attachment actuation device  600 ′ configured to hold compression plates without adapters. Note that compression plate apparatus  300 ′ depicted in  FIGS. 12C-12F  is another embodiment of a compression plate apparatus with plates that snap-fit together. First plate engager  600   a  is fixedly mounted on a rail  640  while second plate engager  600   b  is movably mounted on rail  640 . Second plate engager  600   b  is preferably glidably mounted on rail  640  with a fixed orientation such that it can be advanced toward first plate engager  600   a  to compress the compression plate apparatus  300 . Second plate engager  600   b  is held in a fixed orientation due to the position of groove pin  644  extending through or from rail  640  which is positioned in groove  634  of first plate engager  600   a . Note that as shown below in reference to  FIG. 15A-15C , the attachment actuation device need not be part of the same apparatus with the anvil pull engager and the cutter. 
     Anvils 
     As discussed above in reference to anvil  210 , the anvil provides a surface at its engaging end for engaging the cutter. The engaging end is also in direct contact with the blood vessels intima at the anastomosis site when the anvil abuts the receiving blood vessel wall. The term “anvil” is meant to encompass objects with the characteristics described herein which present at least one surface that is adapted to engage a cutter. 
     The anvil is preferably sized at its engaging end to have a greater cross-sectional area than a cross-sectional area defined by the perimeter of the cutting edge of the cutting device such that portions of the engaging end of the anvil extend beyond the cutting edge when the cutting device engages the anvil and forms the first vessel opening. This size differential is particularly useful for cutting when the cutting device is a mechanical cutter or knife as it permits the anastomosis fenestra or vessel opening to be formed through the action of the cutting edge  414  be pressed against engaging end  212 . This is a significant improvement over conventional cutting techniques that involve the external positioning of an anvil into the lumen of a vessel that is smaller than the cutter so that the vessel is cut as the cutter passes over the anvil. Such conventional cutting techniques operate much like a typical hand held paper punch used for forming holes by pushing a cutter over an anvil Just like paper punches such vascular punches often fail to fully make the cut and leave a portion attached. The connective tissue in blood vessels in combination with the moist condition of the blood vessels further limit the effectiveness of such prior art cutting techniques. More particularly, cutting a moist highly interconnected material by squeezing it between the anvil and the cutter often results in part of the tissue merely slipping between the anvil and the cutter such that a portion is still attached. 
     In addition to cutters that are essentially tubular knives, additional cutting devices are described below in the section entitled Cutting Devices. These cutting devices include devices that utilize a radiation source, such as a surgical laser, that emit radiation of the appropriate characteristics to open the anastomosis fenestra in the receiving blood vessel wall. Such cutting devices that utilize radiation to ablate the vessel wall are also preferably used with an anvil having a cross-sectional area at its engaging end that is larger than the cross-sectional area defined by the perimeter of the cutting edge of the cutting device. While it is useful to have an anvil with an engaging end that extends beyond the cutting edge or the perimeter of the portion that cuts through the use of radiation to localize the impact of the cut, such as minimization of heat transfer, the engaging end need not necessarily be larger for use with such cutting devices. 
     Anvil  40  is preferably made of a puncture resistant material that can withstand the abrasive action of a cutting element. For example, anvil  210  may be formed from a hard plastic material such as Delrin® acetal resins or a high density polyurethane or from a metal such as stainless steel in order to withstand the abrasive action of a cutting device or of a sharp pointed end. When cutting the anastomosis fenestra with radiant energy, the anvil of this invention is preferably coated with radiation absorbing material that prevents radiation scattering. Such coated anvil embodiments are hereinafter referred to as “laser shielded anvils”. 
       FIGS. 7A-7D  provides examples for several embodiments of the anvil of this invention. A line  248  is a visual aid drawn through anvils  210   a - d  to clearly indicate that the portion of the anvil extending from line  248  to the anvil pull is the engaging end  212   a - d . Engaging ends  210   a - c  are all spherical engaging ends like spherical engaging end  212  of anvil  210 . Note that these spherical engaging ends are essentially a hemisphere at the side of the anvil proximal to the anvil pull  230 . When the cutting device is cylindrical and is configured such that it permits part of the spherical engaging end of the anvil to be positioned in the chamber  420  then the cutter self centers on a spherical engaging end. 
     Landing  214  of anvil  210  is also useful feature when the anvil is used in combination with a compression plate apparatus or some of the means for joining a portion of the first vessel that defines the first vessel opening to a portion of a second vessel that defines a second vessel opening such that the first vessel and the second vessel are anastomosed together and are in fluid communication. As noted above, landing  214  is essentially the surface of the cylindrical portion of anvil  210 . When an anvil with a spherical engaging end and cylindrical landings such as anvil  210  is used with a compression plate apparatus such as apparatus  300  then the spherical engaging can extend through first compression plate opening  320   a  and into the apparatus while landing  214  abuts the wall of blood vessel  20  against holding tabs  314   a . The tolerance between landing  214  and holding tabs  314   a  is such that landing  214  initially rests against holding tabs  314   a  until sufficient force is applied to pull anvil  210  through compression plate apparatus  300 . As shown in  FIGS. 4B-4C  and  FIGS. 12D-12E , landing  214  assists in the eversion process before anvil  210  is pulled through the compression plate apparatus. More particularly, landing  214  enables the portion  26  defining the first vessel opening  24  to be everted as everted portion  56  of graft vessel  50  is pushed against portion  26 . As everted portion  56  pushes against portion  26 , portion  26  curls up and over holding tabs  314   a . This process preferably fully everts portion  26 , however, satisfactory results are obtained even if portion  26  is only partially everted. 
       FIG. 7A  depicts an anvil  210   a  that has a landing  214   a  which is slightly flared so that it tapers toward the engaging end  212   a . This may further assist in achieving a desired eversion.  FIG. 7B  shows an anvil  210   b  having a rounded flange at its terminal end  218  which may also assist in everting the portion of the vessel that defines the vessel opening. 
       FIG. 7C  depicts an anvil  210   c  that has a spherical engaging end  48  opposite from a tapered terminal end. As explained below, many features described herein in reference to an intraluminally positioned anvil apparatus also relate to an externally directed anvil apparatus. As shown in  FIGS. 16A-16E ,  FIGS. 17A-17C ,  FIGS. 18A-18B ,  FIGS. 19A-19B , an anvil  210  may be inserted though a wall of a blood vessel at an insertion opening that has been selected as an anastomosis site and positioned in a lumen of the first vessel with the anvil pull  230  extending through the insertion opening of the blood vessel. Note that such use may require some modifications. For example, use of an anvil with a tapered end such as tapered end  218   c  minimizes the size needed for the insertion opening since the vessel wall can stretch as the taper of the anvil increases. 
       FIG. 7D  depicts an anvil  210   d  having an elliptical engaging ends that is adapted to receive a cutter with a corresponding elliptical configuration for the formation of elliptical openings in vessels. As described in greater detail in reference to  FIGS. 14A-14C  and  FIGS. 16A-16B , it is often necessary to attach vessels in a nonperpendicular configuration such that it is Y-shaped instead of T-shaped. Like anvil  210   c , anvil  210   d  has a tapered terminal end for ease in use as an externally positioned anvil apparatus. While reference is made to spherical engaging ends it should be noted that noncircular engaging ends that are convex such as the elliptical engaging end of anvil  210   d  may also be utilized to achieve the desired eversion, particularly when the anvil has an appropriately configured landing. 
       FIG. 8  depicts another embodiment of an anvil apparatus  200 ′. Anvil apparatus  200 ′ has a positioning stem  240 ′ used to push anvil  210  to the anastomosis site through a positioning catheter  140 ′. Accordingly, when using anvil apparatus  200 ′ it is not necessary to utilize a piercing catheter or a piercing wire. Note also that anvil apparatus  200  has an anvil pull with a sharp piercing end  232 ′ instead of a blunt or rounded penetration end  232  like anvil apparatus  200 . The pointed configuration of piercing end  232 ′ enables it to make initial piercing  15  in the wall of vessel  20  by puncturing the wall from its intima outward without causing undue tearing around the puncture. Piercing end  232 ′ is then pulled from the outside of receiving blood vessel  20  just like penetration end  232  of anvil pull  230 . Note that anvil pull  230  of anvil apparatus  200  may have either a distal end that is rounded or blunt like penetration end  232  or sharp such as piercing end  232 ′. 
     Anvil apparatus  200 ′ is not shown with a stopping element such as stopping element  236  of anvil apparatus  200 . Anvil apparatus  1000  in  FIG. 17A  also is not shown with a stopping element as its anvil pull and anvil are integral. However, anvil apparatus  200  may utilize a stopping element such as the stopping elements discussed in detail in the above section entitled Methodology Overview. For embodiments with an anvil that is nonintegral with the anvil pull, the stopping element holds anvil stationary relative to the anvil pull such while withstanding a pressure exerted at the engaging end of the anvil due to the resistance exerted by the receiving blood vessel wall being distended by the anvil and the pressure of the cutting device against the engaging end. 
     Anvil apparatus  200 ′ is positioned through positioning catheter  140 ′ by first introducing anvil pull  230 ′ and then pushing positioning stem. When the anastomosis site is reached, then anvil pull  230 ′ is pushed out of positioning catheter  140 ′ and through initial piercing  15  until the engaging end  212 ′ of anvil  210 ′ abuts the interior of the wall of vessel  20 . Catheter  140 ′ may be positioned within lumen  28  of blood vessel in the same manner as catheter  140 . 
     Distal end  142 ′ may be adapted for providing a lateral exit for piercing end  232  of anvil pull  230 . Distal end  142 ′ may have a deflecting surface and a lateral aperture that guides piercing end  232  towards the intima of receiving blood vessel  20 . Because piercing end  232  is very sharp, such deflecting surface is preferably a puncture and abrasion resistant surface. In addition, distal end  142 ′ may have an appropriate marker for imaging the orientation of the aperture at distal end  142  and/or the position of distal end  142  itself. Such radio-opaque markers can be any of the radio-opaque markers known in the practice of angiography. Similarly, all of the catheters used in the anastomosis procedure may have radio-opaque portions. Anvil pull  230 ′ is typically radio-opaque itself, although very thin embodiments of this wire are preferably coated with a material such as gold or a biocompatible barium-containing substance to make them more visible. Catheter distal end configurations for directing outwardly an elongated member have been disclosed in U.S. Pat. Nos. 4,578,061, 4,861,336, 5,167,645, 5,342,394, and 5,800,450, which are hereby incorporated by reference in their entirety. 
     The dimensions of any of the embodiments of the anvil of this invention are determined by the size of the lumen of the receiving vessel and by the dimension of the passage that will ensure the fluid communication between the graft vessel and the receiving vessel after they have been anastomosed. These dimensions are typically chosen or known in the art. For example, when a graft vessel of about 4 mm in diameter is to be anastomosed to a receiving blood vessel which has an approximate lumen diameter of about 8 mm, the diameter of anvil at its widest may range from about 3 mm to about 6 mm. So for anvil  210 , the diameter at landing  214  may range from about 3 mm to about 6 mm for use in such a vessel. However, the anvil may have any suitable size that enables it to be positioned as needed. Note that the anvil is preferably designed so that the blood flow through the receiving blood vessel will preferably not be interrupted during the anastomosis. However, the design can be such that the blood flow is interrupted when this feature is desired. 
       FIGS. 9A-9B ,  FIGS. 10A-B  and  FIGS. 11A-B  each depict an anvil apparatus with an anvil that is deployable after reaching the anastomosis site such that they have an expanded size when needed.  FIGS. 9A-9B  and  FIGS. 10A-B  depict mechanically deployable anvils while  FIGS. 10A-10B  depict a chemically deployable anvil. 
     The anvil apparatus depicted in  FIGS. 9A-9B  is identical to that of anvil apparatus  200  except anvil  210  is smaller and two flexible anvil sheaths  260   a - b  are positioned on anvil pull  230 . Flexible anvil sheaths  260   a - b  are adapted to be nested as shown in  FIG. 9B  once the wall of vessel  20  is encountered to cause the flexible anvil sheaths  260   a - b  to be dislodged from their positions on anvil pull  230 . Anvil sheaths  260   a - b  may be retained in their spaced positions on anvil pull through reliance on a tight frictional fit or stops may be utilized to ensure that the sheaths are not dislodged until desired at the anastomosis site through application of an appropriate amount of force. When nested on anvil  210 , flexible sheaths  260   a - b  and anvil  230  act together as an anvil. The anvil sheaths may be relatively soft compared to anvil  230  so it may be necessary to treated the anvil sheaths with a puncture resistant material or an abrasion resistant material. 
       FIGS. 10A-10B  depict a flexible anvil  210 ″ that is narrow when collapsed and becomes wider when its engaging end  212 ″ encounters the wall of blood vessel  20 . The engaging end  212 ″ of anvil  210 ″ is not attached to anvil pull  230 , only terminal end  218 ″ is attached to anvil pull. Since anvil  210 ″ is hollow, it can flex into an expanded or deployed position when engaging end  212 ″ is pushed toward terminal end  218 ″. 
       FIG. 11A  depicts a balloon anvil  210 ′″ in a deflated condition extending from a hollow tubular anvil pull  230 ″.  FIG. 11B  depicts balloon anvil  210 ′″ deployed in an inflated condition ready for engagement against the interior of a vessel at an anastomosis site. Balloon anvil is preferably chemically deployed by being filled with a polymerizable material that hardens in situ. For example, syringe  280  may be coupled to tubular anvil pull  230  to enable a composition to be delivered that includes conventional monomers that rapidly polymerizes in the presence of appropriate chemical initiators. 
     For example, the monomers may be suitable acrylates such as urethane dimethacrylate, p-hydroxyphenyl methacrylamide, butane diol dimethacrylate, and bisphenol-A-diglycidyl dimethacrylate (“Bis-GMA”). Examples of appropriate chemical initiators include a wide range of peroxides, other per components, and other free radical generators. An appropriate two-part chemical curing system typically includes a peroxide constituent in one part and an amino compound in another. Exemplary peroxides include benzoyl peroxide, 2-butanone peroxide, lauroyl peroxide and tert-butyl peroxide. Examples of amino compounds include dimethylamino ethyl methacrylate, triethyl amine, 2-dimethylamino ethanol, diethylamino ethyl methacrylate, trihexyl amine, N,N-dimethyl-p-toluidine, N-methylethanolamine, and 2,2′(p-tolyimino) diethanol. 
     After the polymerizable material, the mixture of monomers and chemical initiators, has been delivered into balloon anvil  210 ′″ then it is necessary to wait for the material to polymerize such that anvil  210 ′″ is hard. As shown in  FIG. 11B , once the polymerizable material has hardened then anvil pull  230 ″ is anchored in polymerized material  222  and polymerized material  222  is surrounded by balloon  220 . Since anvil pull  230 ″ is anchored in polymerizable material  222 , balloon anvil  210  can be used in a cutting process without regard to the softness of balloon  220 . More particularly, if a cutter  400  presses through balloon  220  then it merely rests on the exposed polymerized material  222  with the cut portion of blood vessel  20  and is removed along with the entire anvil apparatus  200 ′″. 
     Balloon anvil may also be merely inflated with gas or an appropriate fluid; however, such a balloon anvil is best utilized with embodiments that do not require the anvil to be puncture resistant such as a cutting device that uses radiation followed by steps such as gluing, welding or soldering to join the vessels together. Of course, it may be necessary to treat the engaging end of a balloon anvil such that it is laser shielded by placing a laser shield material at the engaging end of the balloon anvil. One example of a laser shield material is a shield consisting of a sandwich of polymethylmethacrylate and tinfoil that is known to provide corneal and retinal protection from inadvertent injury during argon, Nd-YAG or dye laser treatment at the tested laser power outputs. Similarly, the balloon anvil may be treated with an appropriate material such that it is puncture resistant or distortion resistant. 
     The balloon may also be a puncture resistant balloon. Puncture and scratch resistant balloons have been disclosed in U.S. Pat. Nos. 5,766,158, 5,662,580, 5,620,649, 5,616,114, 5,613,979, 5,478,320, 5,290,306, and 5,779,731, which are hereby incorporated by reference in their entirety. In still another embodiment of this invention, the anvil of this invention can be embodied by the combination of a balloon and a puncture resistant balloon sheath. A balloon plus balloon sheath combination has been disclosed in U.S. Pat. No. 5,843,027 which is hereby incorporated by reference in its entirety. 
     In summary, the anvils are configured in a way such that it effectively cooperates with the cutting device to form the opening of the anastomosis fenestra. The anvils also cooperates in the eversion of the edge of the anastomosed fenestra. Furthermore, the anvil of the present invention is configured so that it can abut the receiving blood vessel wall at the anastomosis site from the intraluminal space of such blood vessel. In addition, the anvil of this invention is configured so that it effectively cooperates with the compression plate apparatus in the joining of the anastomosed structures. The anvils disclosed herein are all examples of anvil means for engaging the interior surface of a first vessel at an anastomosis site. The anvil means that are part of an intraluminally directed anvil apparatus are more specifically anvil means for engaging the interior surface of the wall of a first vessel at an anastomosis site wherein the anvil means is sized to pass within the lumen of the first vessel from an insertion site to a remotely located anastomosis site. 
     Compression Plate Apparatus 
     As indicated above, the plates are configured so that they provide support to the everted openings of the anastomosed structures and facilitate the eversion of the receiving blood vessel, the vessel to which another vessel is being attached that has been everted before initiating the procedure. The compression plate apparatus also eliminate the need for skilled suturing. Use of the compression plate apparatus makes anastomosis procedures more efficient in a reliable manner. Additionally, the compression plate apparatus holds the anastomosed structures in an effective leak proof contact engagement. 
     In each compression plate, the side which is in contact with the everted contour of the anastomosed structure is described as the anastomosis side. In the practice of an anastomosis according to this invention, compression plates are used in a way such that the anastomosis sides of the two compression plates are opposite to each other. Preferred embodiments of compression plates have a generally annular shape with interior openings which have a generally circumferential contour; the internal diameter of each one of these openings is such that the corresponding portion of the vessel to be anastomosed can fit therein. Typically, this internal diameter is approximately equal to, or slightly greater than, the external diameters of the corresponding portion of the vessel to be anastomosed. An internal diameter slightly greater than the external diameter of the corresponding portion of the vessel to be anastomosed is preferred. With this internal diameter, the compression plate does not pose a significant obstacle to the periodic dilation that the vessel is subject to as a consequence of the characteristics of the fluid flow that circulates through the anastomosed structures. 
     There are two primary embodiments disclosed herein including the guided compression plate apparatus  300  shown in  FIGS. 3A-3B ,  FIGS. 4A-4E ,  FIGS. 5A-5B ,  FIGS. 6C-6E  and the snap-fit compression plate apparatus  300 ′ shown in  FIGS. 12A-12G . A variation of compression plate apparatus  300  is also shown at  300 ″ in  FIG. 13  to show that a compression plate apparatus can also be used for joining vessel together in a nonperpendicular orientation. Each plate has an opening  320   a - b  that is generally round, however, as shown in  FIG. 13 , the openings may also be ellipsoidal, ovoid, or have other noncircular configurations. The compression plate apparatus can be used in combination with either an intraluminally directed anvil apparatus or an externally positioned anvil apparatus. 
     Compression plate apparatus  300  is best viewed in  FIGS. 3A-3B . Compression plate apparatus  300  has a compression plate  310   a  is referred to as a first compression plate or a receiving vessel compression plate while compression plate  310   b  is referred to as a second compression plate or an attaching vessel compression plate. As discussed above, compression plate apparatus  300  is shown in  FIG. 3A  before graft vessel  50  has been loaded onto holding tabs  314   b  of second compression plate  310   b  while  FIG. 3B  shows graft vessel  50 . 
     Compression plates  310   a - b  are provided in the exemplary embodiment shown in  FIG. 3A  with a plurality of holding tabs  314   a - b  respectively protruding from opposing anastomosis sides  322   a  (not shown) and  322   b  of compression plates  310   a - b . More particularly, holding tabs  314   a - b  extend respectively from rings  312   a - b  of compression plates  310   a - b . Holding tabs  314   a - b  are intended to hold the everted contours of the structures being anastomosed. Each one of holding tabs  314   a - b  has a base that integrally extends from the anastomosis side of the ring  312   a - b  of the corresponding plate at  313   a - b  and that terminate at rounded tips  316   a - b . Distal tips  316   a - b  are preferably rounded as shown to minimize the potential for penetration. However, in some embodiments, the distal tips may be pointed, for example, when holding a graft vessel. Holding tabs  314   a - b  are typically rather rigid, however, they may also be designed to elastically bend in such a way that the distal tips of such holding tabs slightly swing about their respective bases. Such a bending action may be caused by the displacement through any of openings  320   a - b  defined by holding tabs  314   a - b , more particularly the distal tips  316   a - b  of holding tabs  314   a - b.    
     The number of holding tabs and their spacing may be varied as need as long as the portions of the vessels defining the vessel openings can be maintained in an everted orientation. For example, the plurality of holding tabs may include sixteen holding tabs as shown in  FIG. 3A . However, smaller amounts may also be utilized, for example there may be only six to ten holding tabs. 
     Holding tabs such as holding tabs  314   a - b  can have a plurality of shapes. The holding tabs preferably used in embodiments of this invention are wider at the base and so configured as to extend into a distal rounded tip at the end opposite to the base. Although holding tabs  314   a - b  can be distributed in a variety of arrays, a generally regular distribution on the anastomosis sides of the compression plates is preferred. 
     Each of the holding tabs shown in the embodiment schematically depicted in  FIG. 1  is attached at its base  316   a - b  at the inner peripheries  313   a - b  of rings  312   a - b . However, the bases  316   a - b  may also extend from other locations of the rings. For example, the bases  316   a - b  may extend from rings  312   a - b  between the outer peripheries  311   a - b  and the inner peripheries  313   a - b  or perimeter on the anastomosis sides  322   a - b  of each annular compression plate. 
     Although, it is not necessary for the holding tabs in each compression plate to be oriented relative to the holding tabs in the other compression plate in a mating configuration, it is preferred. When referring to the relative configuration of the holding tabs in opposing compression plates, the terms “mating or mated configuration” describe a configuration in which each one of the holding tabs in a compression plate can generally fit in the space between two neighboring holding tabs in the opposing compression plate when such compression plates are close enough. As shown by the phantom lines in  FIG. 3A , holding tabs  314   b  are offset from holding tabs  314   a  such that as the plates are brought towards each other each holding tab  314   b  is positioned opposite from the spaces between holding tabs  314   a  in a mated configuration. When the compression plates are brought together just close enough for the tips  316   a - b  to be in the same plane, then the everted tissue is held in place and the anastomosis is secure. Failure to bring the compression plates sufficiently close together such that the tips  316   a - b  are significantly close together risks the potential loss of the tissue that has been captured and everted onto holding tabs  314   a - b . Note that each holding tab  314   b  is shown just barely entering into an opposing space between adjacent holding tabs  314   a . Of course, the compression plates may be designed for further compression such that holding tabs  314   b  further enter the space between adjacent holding tabs  314   a . However, the compression plates are preferably designed such that the plates are brought together without penetrating blood vessel  20  or graft vessel  50 . Note that guides  330  maintain the orientation of the compression plates so that the respective teeth have the preferred mating configuration. 
     An example of a suitable compression is provided by a compression plate apparatus having holding tabs with lengths of 0.045 inches (0.1143 cm) that has a distance between the anastomosis sides  322   a - b  of rings  312   a - b  of 0.090 inches (0.2286 cm). Compression down to only 0.10 inches (0.254 cm) for such a compression plate apparatus is generally insufficient to hold the anastomosed tissues. The plates may be further compressed such that the distance between the anastomosis sides  322   a - b  is 0.080 inches (0.2032 cm) or 0.070 inches (0.1778 cm) to bring vessel  20  and vessel  50  even closer together. However, as noted above, it is preferable to avoid pushing through the vessels. The compression plate are accordingly designed to permit compression down to the ideal spacing between the anastomosis sides while providing holding tabs that are long enough to capture the tissue in an everted configuration. 
     The holding tabs such as holding tabs  314   a - b  are preferably configured in a way such that they are not exposed to blood flowing through the anastomosed structures. Some embodiments of this invention are provided with holding tabs that are coated with a biocompatible non-thrombogenic material to prevent the formation of thrombi if such holding tabs or any portion thereof becomes exposed to blood flow. An example of such material is teflon. 
     Holding tabs of a variety of shapes which are distributed in varying numbers and arrays on the anastomosis sides of compression plates  310   a - b  and equivalents thereof are exemplary embodiments of means for holding a portion of a vessel that defines the vessel opening. As indicated above, the holding tabs preferably hold the portion of the vessel that defines the vessel opening in a manner such that the portion defining the first vessel opening is at least partially everted and is not penetrated. The holding tabs disclosed herein are all examples of holding means for holding a portion of a first vessel that defines a vessel opening in manner such that the portion defining the vessel opening is at least partially everted and is preferably not penetrated. 
     As indicated above, guides  330  permit the relative approach of these two plates as compression plate  310   b  slides along guides  330  towards compression plate  310   a . More particularly, guides  330  enable compression plates  310   a - b  to be brought together in a manner such that second compression plate  310   b  is moved in a fixed parallel orientation relative to first compression plate  310   a . Additionally, guides  330  are positioned relative to holding tabs  314   a - b  and have a length that permits graft vessel  50  to be loaded onto holding tabs  314   b  and then be brought into contact with blood vessel  20 . Stated otherwise, the configuration of guides  330  enables first vessel opening  24  and second vessel opening  54  to be initially spaced apart and opposite from each other and then to be advanced toward each other as second compression plate  310   b  is moved with graft vessel  50  held on the holding tabs  314   b  while blood vessel  20  is held by holding tabs  314   a  of compression plate  310   a . As best shown in  FIGS. 4A-4D , movement of second compression plate  310   b  toward first compression plate  310   a  brings the portion  56  of graft vessel  50  that defines the second vessel opening  54  into contact with the portion  26  of blood vessel  20  that defines the first vessel opening  24  such that the blood vessel and the graft vessel are anastomosed together. 
     Compression plate  310   b  is slidably mounted on guides  330  at guide apertures  334 . To slide compression plate  310   b  along guides  330 , each one of ends  332  of guides  330  is introduced through one of guide apertures  334  of compression plate  310   b . Ends of guides  330  opposite to ends  332  are attached to ring  312   a  of compression plate  310   a , however, guides  330  may also integrally extend from ring  312   a.    
     As shown, the compression plate apparatus preferably has a plurality of guides. While compression plate anastomosis  300  is shown with four guides  330 , other embodiments may have other configurations such that the plurality of guides includes, for example, three to six guides. Further, other embodiments may have less than three or more than six guides. It is even possible to have only one guide. Although guides  330  can be distributed in a variety of arrays, a generally regular distribution is preferred in embodiments with more than one guide. 
     When compression plates  310   a - b  are in close proximity to each other at an anastomosis site providing support to the anastomosed structures, terminal ends  332  of guides  330  can extend away from compression plates  310   a - b  to an extent such that the protrusion results in the presence of an undesirable feature in the immediate neighborhood of the anastomosis site. To solve this problem, embodiments of the compression plate devices of this invention are provided with guides  330  which can be appropriately shortened by removing an appropriate length of terminal ends  332 . In some embodiments, terminal ends  332  are manufactured with a material which dissolves after an appropriate time following the anastomosis. In other embodiments, guides  330  are made of a material that can easily be clipped to a desired length, thus eliminating terminal ends  332  as shown in  FIG. 4D . In other embodiments, guides  330  can be provided with notches or some other localized weakened structural feature which facilitates the easy removal of terminal ends  332  at desired distances with respect to plate  310   a . Still other embodiments can be provided with terminal ends  332  that can easily bend to an extent such that undesirable protrusions are eliminated. 
     The guides may have a variety of lengths and be distributed in varying numbers and arrays. The guides may also extend from one or both of the compression plates at any appropriate location. However, the guides are preferably situated such that the portion  26  defining the blood vessel opening  24  and the portion  56  defining the graft vessel opening  54  are joined without being penetrated as the first vessel and the second vessel are anastomosed together. The guides disclosed herein are exemplary embodiments of means for guiding the movement of one compression plate with respect to the other compression plate. More particularly, the guides disclosed herein are examples of means for guiding the movement of one compression plate relative to the other such that one compression plate moves in a fixed parallel orientation relative to the other compression plate. 
     Guide apertures  334  are sized to frictionally engage guides  330  in a manner such that compression plate  310   b  does not inadvertently slide on guides  330 , particularly not after being compressed towards compression plate  310   a . In the absence of a suitable frictional engagement, compression plate  310   b  may slide away from compression plate  310   a  to potentially jeopardize the leak-proof character of structures held together by the compression plates. An undesired separation could be caused, for example, by an expansion of the anastomosed structures at the anastomosis site, caused in turn by the pressure exerted by the fluid circulating therethrough. 
     When second compression plate is formed from plastic, the desired frictional engagement is generally achieved whether guides  330  are made from metal or plastic. However, when second compression plate is formed from metal and the guides are also metal, it is preferable to utilize an alternative frictional engagement. For example,  FIG. 5A  shows compression plate apparatus  300  with an optional holding ring  340  that has a friction coupling with guides  330  through its guide orifices  346 . Holding ring  340  is provided with opening  348  whose internal diameter is preferably at least equal to that of the opening  220   b  of compression plate  310   b . The frictional engagement of holding ring  340  with guides  330 , like the frictional engagement described above for guide apertures  334  with guides  330 , is such that expansion of the anastomosed structures can not separate compression plates  310   a - b  with respect to each other when holding ring  340  is in contact engagement with exterior side  324   b  (not shown) of compression plate  310   b  opposite to its anastomosis side  322   b . The holding ring may, for example, be formed from nylon. 
     Other embodiments of this invention are provided with different frictional engagements that are designed to prevent compression plate  310   b  from significantly moving away from compression plate  310   a . For example, guides  330 ′ of compression plate apparatus  300 ″ in  FIG. 13  have barbs  336 . These frictional engagement configurations described above enable the compression plates to be approached to a desired relative separation and maintained at that separation. This feature also permits the control of the pressure applied to the everted tissue of the anastomosed structures and the compression of the plates in stages so that they are approximated in a controlled manner. 
     These frictional engagements are all examples of means for locking the compression plates together. More particularly, guides that engage appropriately sized apertures  334  of second compression plate  330   b  for frictional engagement, a holding ring  340  that has guide orifices  346  sized to fractionally engage a guide  330 , and guide barbs  336  for irreversible advancement of second compression plate  310   b  as the guide extends through guide apertures  334  of second compression plate  310   b  are all examples of means for locking the compression plates together. Note that when the frictional engagement is achieved through reliance on guides that extend from a first compression plate and that pass though appropriately sized apertures in the second compression plate then it can be said that the first compression plate and the second compression plate have means for locking the compression plates together. An advantage of such locking means that are part of the first and second compression plates is that it is not necessary to separately attach the locking means to the compression plate apparatus after it has been used to anastomose the vessels. 
     The compression plate apparatus is preferably used for vascular anastomosis, however, the present invention is not limited to such use. Nor is the compression plate apparatus limited to use with any particularly sized vessel. For example, vessels may be joined with diameters ranging from about 2 mm to about 20 mm, but there is no fundamental limitation for using embodiments of this invention with graft vessels with diameters less than 2 mm. 
     A variety of techniques known in the art can be used to manufacture compression plates within the scope of this invention depending on the material used. Compression plate apparatus  300 ,  300 ′ and  300 ″ can be formed from a plastic material such as nylon or from metals such as titanium or nickel/titanium alloys. Stainless steel can be used but is not preferred. Additionally, one plate may be formed from a metal while the other is formed from plastic. In addition to molding the plates, when the plates are formed from metal, the plate may be cut from a disk in a flat configuration and then the holding tabs can be bent into position. 
     Although guides such as guides  330  provide a convenient structural element for appropriately orienting and approaching the compression plates of this invention relative to each other, the appropriate orientation and relative displacement of the compression plates can be achieved in other ways that accomplish the same effects as discussed for example in reference to compression plate apparatus  300 ′. These different ways of providing the appropriate relative orientation of the compression plates and the relative displacement are within the scope of this invention. For example, a device used to hold the compression plates as shown in  FIG. 6D-6E ,  FIG. 12C-12G , and  FIG. 16C  can provide the appropriate support for orienting and displacing the compression plates relative to each other. Similarly, the cutting device may be configured to provide the appropriate orientation. 
       FIGS. 12A-12B  provide a perspective view of snap-fit compression plate anastomosis apparatus  300 ′. Like guided compression plate apparatus  300 , snap-fit compression plate apparatus  300 ′ has two opposing compression plates including a first compression plate  310   a ′ and a second compression plate  310   b′.    
     First compression plate  310   a ′ has a ring  312   a ′ with an inner periphery  311 ′ and an outer periphery  313 ′. A plurality of holding tabs  314   a ′ extend from ring  312   a ′. Like holding tabs  314   a , each holding tab  314   a ′ has a base  316   a ′ and terminate at a distal rounded tip  315   a ′. The base of each tab is preferably integral, as shown, with ring  312   a ′. Each holding tab  314   a ′ extends at its base from ring  312 . More particularly, each holding tab  314   a ′ extends from inner periphery  311 ′ from exterior side  324   a ′ toward anastomosis side  322   a ′ (not shown). 
     Holding tabs  314   a ′ extend either perpendicularly from ring  312   a ′ of first compression plate  310   a ′ or curve inward from exterior side  324   a ′ of ring  312   a ′ of first compression plate  310   a ′ such that distal rounded tips  316   a ′ of holding tabs  314   a ′ are nonperpendicularly oriented relative to exterior side  324   a ′ of ring  312   a ′ of first compression plate  310   a ′. Like holding tabs  314   a , holding tabs  314   a ′ may have varying configurations and various numbers of holding tabs may be utilized. 
     First compression plate  310   a  also has a plurality of locking arms  350  extending from outer periphery  311   a ′. Locking arms  350  are adapted to lock with a locking extension  360  projecting from second compression plate  310   b ′. Engagement of these locking components enables compression plates  310   a ′- 310   b ′ to lock together such that the portion  26  defining the first vessel opening  24  and the portion  56  defining the second vessel opening  54  are joined without being penetrated as the first vessel and the second vessel are anastomosed together. 
     Locking arms  350  have a length that enables them to lock around locking extension  360  in a manner such that the portion defining the first vessel opening and the portion defining the second vessel opening are held together without being damaged in a manner that causes the anastomosis to fail. Each locking arm  350  has a pivot portion  352  that terminates at a grasping portion  354 . Grasping portion  354  is preferably a curved portion of locking arm  350  directed annularly inward. 
     Second compression plate  310   b ′ has a second compression plate opening  320   b ′, or more precisely, an anastomosis side opening  320   b ′, defined by a holding surface  364 . Second compression plate opening  320   b ′ may also be described as being defined by rim  368  which is the point at which holding surface joins tubular portion  370 . Holding surface  364  extends radially downward at an angle from anastomosis side opening  320   b ′ and terminates at locking extension  360  such that second compression plate  310   b ′ flares in diameter from second compression plate opening  320   b ′ down to locking extension  360 . Locking extension  360  has two surfaces, a flaring surface  362  that is continuous with holding surface  364  and a locking surface  366  shown in  FIG. 12C-12G . While locking extension is shown having a flaring surface  362  that is a continuous extension of holding surface  364 , these surfaces may also be distinct. 
     Holding surface  364  has a configuration that permits the portion of the second vessel  50 ′ defining the second vessel opening  54 ′ to be everted onto holding surface  364  as shown in  FIG. 12B . The vessel shown in  FIG. 12B  everted on holding surface  364  is an autologous or heterologous blood vessel  50 ′. Of course, a graft vessel like vessel  50  can also be used, however, vessel  50 ′ is identified as being autologous or heterologous in order to depict the use of vessels that are not artificial. Everted portion  56 ′ of vessel  50 ′ is preferably adhered onto holding surface  364  through the use of an appropriate adhesive such as those described above in the Background section or attached through the use of stay sutures or other means for holding vessel in an everted position. While holding surface is shown extending radially downward at an angle from the second compression plate opening, it may have any surface that is suitable for everting the portion of vessel  50 ′ that defines opening  54 ′ and for holding the everted portion  56 ′. 
     As shown in  FIG. 12B , tubular portion  370  is adapted to receive vessel  50 ′ through exterior side opening  372  such that graft vessel can pass though anastomosis side opening  320   b ′ and be everted onto holding surface  364 . As shown in  FIG. 12G , exterior side opening  372  is defined by tubular portion  370  and locking surface  366 . The farther that locking surface  366  extends from exterior side opening  372  the greater the distance between vessel  50 ′ and grasping portion  354  once the anastomosis is complete. Tubular portion  370  may have an extension to provide further protection for vessel  50 ′ against contact with grasping portion  354 . Tubular portion  370  may have a slanted orientation corresponding to the angled orientation of holding surface  364 . However, tubular portion is preferably configured such that it has parallel sides as such a configuration enables the barrier between grasping portion  354  of locking arms  350  and vessel  50 ′ to be maximized. 
     Holding tabs  314   a ′ are additional examples of holding means for holding a portion of a first vessel that defines a vessel opening in manner such that the portion defining the vessel opening is at least partially everted and is preferably not penetrated. Holding surface  364  is a also an example of holding means for holding a portion of a first vessel that defines a vessel opening preferably in manner such that the portion defining the vessel opening is at least partially everted and is preferably not penetrated. 
       FIGS. 12C-12G  provide a sequential presentation of the steps involved in utilizing snap fit compression plate apparatus  300 ′ as an anastomosis fenestra is formed in first vessel  20  and as the compression plates are brought together to approximate vessel  20  and vessel  50 . The sequential steps depicted in  FIGS. 12C-12G  are similar to steps depicted in  FIGS. 4A-4D  for the use of guided compression plate apparatus  300 . However,  FIGS. 12C-12G  also show the use of attachment actuation device  600 ′ having a first plate engager  600   a ′ and a second plate engager  600   b ′. Attachment actuation device  600 ′ is slightly different from attachment actuation device  600 , which is described in reference to  FIGS. 6A-6E  in detail in the section entitled External Anastomosis Operator, in that it is not necessary to utilize the optional adapters  610   a - b  since first and second compression plates  310   a ′- 310   b ′ are directly engaged. Each plate engager  600   a ′- 600   b ′ has a component or a portion that directly contacts the plate in a configuration such that the plate is held in a locked manner or such that the plate can be moved. A plurality of screws  615   a ′ lock first compression plate  310   a ′ in place while extension  615   b ′ of second plate engager  600   b ′ pushes second compression plate  310   b ′. First compression plate  310   a ′ may have recesses for receiving screws  615   a′.    
       FIG. 12C  depicts anvil  210  extending through first compression opening  320   a  with its landing  214  abutting first holding tabs  314   a  while cutter  400  and second compression plate are opposite spherical engaging end  212  with anvil pull  230  extending through cutter  400 .  FIG. 12D  depicts cutting edge  414  pressing against spherical engaging end  212  above the portion where spherical engaging end terminates at landing  214 . 
       FIG. 12E  depicts compression plate apparatus  300 ′ as it is being compressed and as portion  26  defining vessel opening  24  is being everted. More particularly, compression plate  310   b ′ has been moved toward compression plate  310   a ′ as second plate engager  600   b ′ is pushed toward first plate engager  600   a ′. Note that the everted portion  56 ′ of graft vessel  50 ′, more particularly the portion  57 ′ opposite from the rim  368 , is urged against portion  26  that defines first blood vessel opening  24  in a manner such that portion  26  is being everted. This eversion process is augment by landing  214  of anvil  210  which allows portion  26  to rest on landing  214  and be plowed upward by everted portion  56 ′. The length of portion  26  is sufficient for this eversion process since vessel  20  was distended and pulled into the snap-fit compression plate apparatus by the action of anvil  210 .  FIG. 12E  also depicts grasping portion  354  sliding on flaring surface  362  as pivot portion  352  extends radially outward. 
       FIG. 12F  depicts portion  26  fully everted on holding tab  314   a ′ such that portion  27  opposite from rounded tip  316   a ′ is held in contact with the portion  57 ′ of vessel  50  opposite from rim  368 . After compression plate apparatus  300 ′ has been compressed to join portion  26  of blood vessel  20  that defines first vessel opening  24  to portion  56 ′ of second vessel  50 ′ that defines graft vessel opening  54 ′ then first vessel  20  and second vessel  50  are anastomosed together and are in fluid communication. Anvil apparatus  200  and cutter  400  have been removed upon the completion of the procedure through lumen  58  of graft vessel  50 . More particularly, once the anastomosis is completed then anvil pull  230  is pulled so that it draws anvil  210  through openings  320   a ,  320   b ′ and  372  of compression plate apparatus  300 ′ such that anvil apparatus  200  is removed along with cutter  400  through lumen  58 ′.  FIG. 12G  depicts vessel  20  anastomosed to vessel  50 ′ after attachment actuation device  600 ′ has been removed. 
     The mated locking components of first compression plate  300   a ′ and second compression plate  300   b ′, namely locking arms  350  and locking extension  366 , are adapted to lock the compression plates together such that portion  26  defining first vessel opening  24  and portion  56 ′ defining the second vessel opening  54 ′ are joined without being penetrated. Such locking components are an additional example of means for locking the compression plates together. Note these locking means are integral parts of each compression plate so it is not necessary to separately attached the locking means to the compression plate apparatus after it has been used to anastomose the vessels. 
       FIG. 13  depicts another embodiment of a guided compression plate apparatus  300 ″ which has components that are almost all identical with those of compression plate apparatus  300  except that the components of compression plate apparatus  300 ″ are oriented for use with a non-perpendicular anastomosis. Note that the end of vessel  50  has been cut at an angle so that it can be attached to a vessel as shown in  FIG. 14C  at an angle. Cutter  400 ′ is also angled so that it can make a cut in a vessel that is elliptical in configuration. Openings  320   a ″- 320   b ″ are also elliptical so that the aligned openings of compression plate apparatus  300 ′, the first vessel opening and the second vessel opening are all elliptical. Guides  330 ″ do not extend perpendicularly from ring  312   a ″ like guides  330 . Guides  330 ″ are all parallel to each other and extend nonperpendicuarly from ring  312   a ″ so that guide compression plate apparatus  300 ″ is shaped like a parallelogram. Guide apertures  334 ″ are also formed with the same angled configuration of guides  330 ″. This configuration enables compression plates  310   a ″- 310   b ″ to be brought together in a manner such that second compression plate  310   b ″ is moved in a fixed parallel orientation relative to first compression plate  310   a″.    
     Holding tabs  314   a - b ″ may also be configured differently than holding tabs  314   a - b  in order to hold angled noncircular vessel openings. Note that guides  330 ″ extend integrally from ring  312 ″ and are not attached. Another difference is the use of guide barbs  336  to provide for irreversible advancement of second compression plate  310   b ″ towards first compression plate  310   a ″ as discussed above with regard to frictional engagements to prevent movement of the plates relative to each other after anastomosis. Note that while snap-fit compression plate apparatus  300 ′ is shown being used for joining vessels with openings that are generally circular, the same principles shown with regard to apparatus  300 ″ can also be used to modify apparatus  300 ′ for use with noncircular openings. 
     Compression plate apparatus  300 ,  300 ′ and  300 ″ are all examples of means for joining a portion of the first vessel that defines the first vessel opening to a portion of a second vessel that defines a second vessel opening. More specifically, they are examples of means for mechanically joining the portion of the first vessel that defines the first vessel opening to the portion of the second vessel that defines the second vessel opening. Other examples of means for mechanically joining the vessels include suture thread, staples, clips, and combinations thereof. An example of the use of staples or clips is shown in  FIG. 14C . 
     The joining means also includes means for chemically joining the vessels. Examples of means for chemically joining the vessels include biocompatible adhesives or glue; solder; biological procoagulant solution; a combination of a chromophore and solder, and combinations thereof. These materials are discussed in detail in the Background section.  FIG. 14D  depicts such materials being delivered in accordance with one embodiment. 
     The joining means also includes radiation-based means for joining the vessels. Examples of radiation-based means for joining the vessels include tissue welding radiation; the combination of substances and radiation for laser sealing, and combinations thereof. The use of radiation for joining vessels is discussed in detail in the Background section.  FIG. 14D  also depicts radiation being delivered to join vessels. 
     Cutting Devices 
     The term “cutter” is used to refer to a tubular knife such as cutter  400 . Cutter  400  is an example of a “cutting device” which is a term used to refer to cutters and any other instrument used to form an anastomosis fenestra or opening that does not rely on the application of mechanical pressure, such as cutting device  400 ″. While cutters that use a radiation source, such as a surgical laser, that emit radiation of the appropriate characteristics to open the anastomosis fenestra in the receiving blood vessel wall are useful, cutting devices such as cutter  400  are generally less expensive. Cutter  400  is preferably formed from stainless steel such that it is sufficiently inexpensive to be a disposable, single use item. 
     These cutting devices disclosed herein are all examples of cutting means for forming an opening in the wall of the first vessel at the anastomosis site through engagement with the anvil of an anvil apparatus as an engaging means holds the anvil pull of the anvil apparatus after receiving the anvil pull through the cutting means. The cutting devices engage an anvil to form the vessel opening in any suitable manner. For example, the cutting device may be pushed against the anvil, the anvil may be pulled against the cutter or both may simultaneously occur such that anvil is pulled as the cutter pushes against the anvil. 
     Cutter  400  is shown in numerous drawings, however,  FIGS. 6C-6E , show its full length and its use in combination with external anastomosis operator  700 .  FIG. 6E  provides the best view of cutter  400 . Cutter  400  is shown in  FIG. 6B-E  as including a tip portion  401  and an extension portion  402 , however, cutter  400  is shown elsewhere as being integral. 
     Anvil pull  230  is shown in  FIG. 6C  extending through cutter  400 . Cutter  400  is hollow so it has a chamber  420  between the sidewalls of cutting tube  410 . Cutter  400  may also have an optional centering core  422  that extends at least part way though chamber  420 . Centering core  422  has a centering conduit  424  that assists in centering anvil pull  230  in cutter  400  such that anvil pull  230  is essentially parallel with the sidewalls of cutting tube. Centering core  422  preferably has a tapered access to guide anvil pull  230  into centering conduit  424 . Another example of a centering conduit is provided by a centering conduit  424 ′ of cutting device  400 ′ shown in  FIG. 14D , as discussed below in greater detail. 
     It is not always necessary for cutter  400  to have a centering core or for other cutting devices to have a centering core or a centering conduit. When the engaging end of the anvil is spherical and the cutter is spherical and is configured such that it permits part of the spherical engaging end of the anvil to be positioned in cutter chamber  420  then the cutter self centers on the spherical engaging end. The entire cutting device need not be hollow. For example, cutting device  400 ″ has a recess  428  at its cutting end that is deep enough to permit the engaging end of anvil  200   d ′ to extend into recess  428  so that anvil  200   d ′ may be centered and seated. Accordingly, the cutting end is preferably adapted to receive a portion of the engaging end into the cutter to enable the engaging end to self center and be seated. Also, the engaging end is preferably convex and more preferably spherical. 
     As shown in  FIG. 6C , cutter  400  is spring biased by a spring biasing device  450  that is described in detail below in the External Anastomosis Operator section. However, to appreciate the benefits of spring biased cutting it should be understood that distal end  418  of cutter  400  is received into a moveable cutter cup  458  which can push against spring  460 . The pressure of spring  460  against cutter cup  458  enables cutter  400  to apply pressure against anvil  210  as anvil  210  is pulled against cutter  400 . This makes it easier to cut the vessels as force is being applied in both directions. More particularly, it reduces the amount of force that would otherwise be required if the only force being applied was through the advancement of anvil  210  by pulling anvil pull. 
     A spring biased cutter also enables the cutter to be pushed back by anvil  210  to allow anvil  210  to further distend the wall of vessel  20  as shown in  FIGS. 4A-4B ,  FIGS. 6D-6E ,  FIGS. 12C-12E ,  FIGS. 15B-15C  and  FIGS. 16D-16E . As anvil  210  pushes cutter  400  through vessel  20 , anvil  210  causes cutter  400  to retract, however, increasing resistance is encountered as spring  460  becomes further compressed. So cutter  400  applies increasing amounts of pressure to vessel  20  as anvil  210  continues to stretch the wall of vessel  20  into compression plate apparatus  300 . By optimizing features such as the tension of the spring and the length of cutter, vessel  20  is distended far enough into compression plate apparatus  300  to leave sufficient lengths of the vessel in the compression plate apparatus for capturing in the subsequent eversion process onto holding tabs  314   a . It has been found that about 17-18 lbs or about 20 lbs is generally required to form the anastomosis fenestra. 
     The gradual increase in pressure also serves to assist a spherical engaging end  212  of anvil  210  to self center on cutter  400 . Since the pressure increases gradually, if anvil  210  is initially misaligned on cutter  400  then the gradual increase in pressure causes the anvil to be gradually drawn to center as the spherical engaging end  212  is pulled into chamber  420  or recess  428  of the cutting device. If pressure is applied too rapidly, the sharp cutting edge  414  of a cutter such as cutter  400  may dig into anvil  210  before anvil  210  can slide into a centered orientation. Accordingly, the use of a cutter with at least a recess at its cutting end and a spherical engaging end accommodates imperfections in the alignment of the cutter and the anvil. 
       FIGS. 14A-14B  depict a simple combination of a cutter engaging an anvil as the anvil pull  230 ′″ is advanced by an anvil pull engager  500 ′ which holds and advances anvil pull  230 ′″. Note that distal end  232  of anvil pull  230  is threaded and anvil pull engager is essentially a wingnut that is correspondingly threaded. As anvil pull engager  500 ′ tightens against the distal end  418  of cutter  400  then anvil pull  230  pulls anvil  200  until cutter  400  is engaged. Of course, an even simpler design is the manual application of pressure by pulling on anvil pull while pushing on cutter without an anvil pull engager. 
       FIG. 14C  depicts an anastomosis fenestra formed through the use of a cutter such as cutter  400 ′. Cutter  400 ′ works in the same way as cutter  400  except that anvil  200   b ′ has an elliptically shaped engaging end and cutter  400  has an elliptically shaped and angled cutting knife  412 ′ and cutting edge  414 ′. Such a combination of an anvil with an elliptically shaped engaging end and a mated cutter with an elliptically shaped and angled cutting knife and cutting edge enable anastomosis to be formed as shown in  FIG. 14C  that involves the nonperpendicular attachment of a vessel to a side of another vessel. The configuration of the opening and the diameter of the opening to be formed depends on factors such as whether the opening is for a venotomy or an arteriotomy. 
     After the opening is formed by cutter  400 ′ then the vessels may be joined in the same way that a vessel is joined perpendicularly to a side of another vessel. For example, the portions defining the openings may be clipped or staples together through the use of a clipping or stapling device  800  that delivers clips  800  or staples. If the vessels are mechanically joined through the use of sutures, staples or clips then it may be desirable to enhance the leak proof character of the anastomosis through the use of laser welding with a conventional laser welding device, such as an endoscopic laser welding devices. Similarly, the seal may be augmented through the appropriate use of biocompatible adhesives administered by conventional delivery devices, including endoscopic glue delivery devices. Additionally, a seal may be formed or strengthened by techniques such as laser soldering, including chromophore-enhanced laser soldering, and laser sealing. 
       FIG. 14D  depicts a device identified as cutter  400 ″ which may be used to form the anastomosis fenestra to permit the angled attachment shown in  FIG. 14C . Cutter  400 ″ has an element  430  that may be embodied by a surgical laser such as a cluster of optical fibers  432  that delivers appropriate radiation. Cutter  400 ″ also has an applicator  440  for delivering a fluid  442  such as biocompatible adhesives or glue; solder; biological procoagulant solution; a combination of a chromophore and solder, and combinations thereof. These materials may be delivered after the element  430  has been used or simultaneously depending on the objective. For example, if fluid  442  is an adhesive then applicator  440  can deliver the adhesive in a controlled manner after the radiation has been delivered to ablate the vessel wall to open the anastomosis fenestra. However, when utilizing element  430  for welding radiation or laser sealing then fluid  442  is preferably delivered before or is simultaneously delivered Also, cutter  400 ″ may be used only to deliver glue after a mechanical cutter such as cutter  400 ′ has been used. Adhesives and solder may be used alone, or as discussed above, adhesives and solder may be utilized to further seal an anastomosis that utilizes a mechanical devices such as clips as shown in  FIG. 14C . 
     External Anastomosis Operators 
     The positioning of the compression plate apparatus and the operations of pulling or holding anvil pull  230 , making an opening, and compressing the compression plates together as described in the foregoing sections can be accomplished by manually actuating these elements or with the aid of devices such as external anastomosis operator  700 . One advantage derived form the use of a device such as external anastomosis operator  700  is that such devices have a series of actuators, and by manipulating these actuators the operator can effectuate the different operations at the anastomosis site without actually having to manually and directly operate each element itself. 
     As shown in  FIG. 6A , external anastomosis operator  700  has a body  710  with an optional handle  720 . Attached to body  710 , are the main components of operator  700 , as identified in  FIG. 6A . These main components are cutter  400 , spring biasing device  450 , an anvil pull engager  500  which includes an anvil pull holder  530  and an anvil pull advancer  560 , and an attachment actuation device  600 . 
       FIG. 6B  provides an exploded perspective view of all of the components of external anastomosis operator  700  so it is with reference primarily to this view that the details of operator  700  are understood.  FIGS. 6C-6E  provide cross-sectional views of operator  700  depicting the steps for using operator  700 . 
     Cutter  400  is shown in  FIG. 6B-E  as including a tip portion  401  and an extension portion  402 . Note that cutter  400  is shown elsewhere as being integral. The advantages of using a spring biasing device  450  to apply pressure against the distal end  418  of cutter  400  are explained above in the Cutting Devices section. However, the components of spring biasing device  450  are described in this section. 
     Spring biasing device  450  has a spring mount  452  that is mounted to body  710  via spring mount pins  454 . A rotatable spring housing  456  is threadably engaged by spring mount  452 . Loaded into rotatable spring housing  456  is a cutter cup  458  that is configured to hold distal end  418  of cutter. Cutter cup  458  has a flange that is pushed against a flange at the proximal end of rotatable spring housing  456  such that cutter cup  458  is held in the proximal end of spring housing  456 . A spring  460  is positioned within a spring sleeve  462 . Spring  460  and spring sleeve  462  have ends that abut cutter cup  458  and opposite ends that abut threaded jam screw  464 . Threaded jam screw  464  is accessible via the distal end of spring mount  452  so that it may be rotated to increase or decrease the tension of spring  460  against cutter cup  458 . 
     Cutter cup  458  moves within rotatable spring housing  456  against spring  460 . As discussed generally above in the Cutting Devices section, the pressure of spring  460  against cutter cup  458  enables cutter  400  to apply pressure against anvil  210  as anvil  210  is pulled against cutter  400 . This makes it easier to cut the vessels as force is being applied in both directions. It also enables cutter  400  to be pushed back by anvil  210  to allow anvil  210  to further distend the wall of vessel  20  as shown in  FIGS. 4A-4B  until sufficient pressure is applied by spring  460  to bias cutter  400  forward and by the advancement of anvil  210  by anvil pull  230  to cut the vessel. The gradual increase in pressure also serves to assist a spherical engaging end  212  of anvil  210  to self center on cutter  400 . More particularly, anvil  210  may be initially misaligned such that the center of engaging end from which anvil pull extends is positioned on cutting edge  414 . A rapid application of pressure would lock such a misalignment while a gradual increase enables the curvature of spherical engaging end to guide the anvil into a centered orientation. 
     Another function of spring biasing device is to set the position of cutter  400 . Rotatable spring housing  456  has a notch  457  at its distal end that enables a screw driver to rotate rotatable spring housing  456  within spring mount  452  to advance or retract rotatable spring housing  456  within spring mount  452 . Movement of rotatable spring housing  456  also moves cutter cup  458 , thereby determining the location of distal end  418  of cutter  400  within operator  700 . Of course advancement of cutter cup  458  towards the proximal end of operator  700  causes cutting knife  400  to be engage anvil  210  closer to first compression plate  310   a  while retraction of cutter cup  458  towards the distal end of operator  700  causes cutting knife and anvil to engage each other closer to second compression plate  310   b . The position of cutter  400  is preferably set to enable vessel  20  to be distended in a manner that is optimal for then subsequently everting the portion defining the newly formed opening onto holding tabs  314   a . To carefully identify the length that rotatable spring housing  456  is advanced or retracted, a detent  470  is threaded into spring mount such that it can contact rotatable spring housing and engage the grooves  471  of rotatable spring housing in a manner that enables detent  470  to click as each groove is rotated past detent  470 . 
     Obviously spring biasing device  450  has many variables that impact the manner in which cutter  400  is used in combination with external anastomosis operator  700 . Some of these variables include the inherent tension of spring  460 , the tension of spring  460  as caused by the position of threaded jam screw  464  in spring mount  452  against spring  460 , and the position of the surface which distal end  418  of cutter  400  abuts, namely cutter cup  660  as determined by the position of rotatable spring housing  456  within spring mount  452 . 
     Spring biasing device  450  is an example of spring biasing means for providing tension against the cutting means as the cutting means engages the anvil means of the intraluminally directed anvil apparatus. The spring biasing means provides an amount of tension that enables the cutting means to form the first vessel opening after the wall of the first vessel has been distended by the action of the anvil means being pulled into the openings of the compression plate assembly such that forming the first vessel opening results in at least partial eversion of the portion of the first vessel defining the first vessel opening. 
     As indicated above, anvil pull engager  500  has two primary components including an anvil pull holder  530  and anvil pull advancer. Anvil pull holder  530  receives anvil pull  230  via spring biasing device  450 . More particularly, anvil pull  230  extends through cutter cup  458 , rotatable spring housing  456 , spring  460  and sleeve  462  around spring  460 , and out of threaded jam screw  464 . 
     Anvil pull holder  530  includes a holder mount  532  positioned in track  730  of body  710 . In this embodiment, holder mount is moveable so that the anvil pull can be advanced after it is held. However, in other embodiments, the anvil pull holder may just lock the anvil pull into position such that the cutter is moved against a stationary anvil. Similarly, the spring biasing device  450  may be eliminated so that the vessel is cut only by pressure exerted by the anvil pull against the cutter. As discussed above, while the cutter and the anvil may engage each other in these arrangements, it is preferable for the cutter to apply some pressure as the anvil pull is advanced against the cutter. 
     Holder mount  532  may be utilized in different ways to hold anvil pull  230 . Holder  530  has a split cone  534  inserted into a tapered chamber  536  against a spring  538 . Anvil pull  230  extends through apertures in holder mount  532 , spring  538 , split cone  534  and out of an aperture centered in holder knob  540 . Holder knob  540  is threadably engaged by holder mount  532  such that rotation of holder knob  540  advances split cone  534  in tapered chamber  536  causing split cone to lock onto anvil pull  230 . As shown in  FIG. 6B , holder mount is slotted at its distal end as is holder knob. By aligning slot  542  of holder knob  540  with the insert slot  544  of holder mount, anvil pull  230  can be bent so that it extends through both holder knob slot  542  and insert slot  544 . Then holder knob  540  can then be rotated so that the bent portion of anvil pull  230  is rotated into one of the locking slots  546   a - b  that extend perpendicularly from insert slot  544 . This securely locks anvil pull into position. Anvil pull  230  can be locked through the use of slots instead of or in addition to the use of split cone  534  in tapered chamber  536 . 
     The anvil pull holders described herein are examples of holding means for holding the anvil pull extending from an anvil. The anvil pull advancers described herein are examples of advancement means for pulling the anvil pull once the anvil pull is held by the holding means. As indicated above, the anvil pull holder may have a fixed position such that it is not moveable. As also indicated above, however, the anvil pull holder is preferably moved via an anvil pull advancer. A fixed anvil pull holder and an anvil pull holder that is moveable via an anvil pull advancer are both examples of an anvil pull engagers. The anvil pull holder and the anvil pull advancer may be separate components such as anvil pull holder  530  and anvil pull advancer  560  or be embodied by a component capable of both holding and advancing the anvil pull such as anvil pull engager  500 ′ shown in  FIGS. 14A-14B . These anvil pull engagers are all examples of engaging means for holding an anvil pull extending from an anvil. Once such engaging means holds the anvil pull then the engaging means can control the position of the anvil at the anastomosis site via the anvil pull. 
     Since anvil pull holder  530  is moveable it threadably engages rotatable lead screw  562  of anvil pull advancer. More particularly, lead screw  562  is threadably engaged by antibacklash nut  550  which is fixedly attached to holder mount  532 . Anti-backlash nut  550  has an attachment face  552  through which a plurality of attachment face screws  554  extend to hold holder mount  532  and anti-backlash nut  550  together. 
     Lead screw  562  has a proximal pivot end  564  that rotates within a bushing  566  positioned within a recess in spring mount  452 . Lead screw also has a distal pivot end  568  that is attached to advancer knob  570  to rotate lead screw  562 . Advancer knob  570  rotates within an advancer knob mount  572  which is attached to body  710  in groove  730  via advancer knob mount bolts  574 . As shown in  FIG. 6C , distal pivot end  568  rotates in a bushing  576  positioned within an aperture of advancer knob mount  572 . 
     Advancer knob  570  has a stem with a plurality of grooves  578  that engage a detent  580  to click so that the incremental rotation of advancer knob  570  can be carefully counted to determine the length that the anvil is moved in the compression plate apparatus as the anvil pull is advanced. As shown in  FIG. 6C , detent  580  is threaded into advancer knob mount  572  such that it can contact grooves  578  in the stem of advancer knob  570  to click as each groove is rotated past detent  580 . 
       FIG. 6D  depicts advancer knob  570  being rotated to move anvil pull advancer  560  so that it can urge anvil pull  230  in a manner such that anvil  210  is advanced within compression plate apparatus  300 . As advancer knob  570  is rotated, lead screw  562  is thereby rotated. Since anvil pull holder  530  is threadably engaged on rotatable lead screw  562  and is locked in track  730 , anvil pull holder  530  can only move forward and backward as lead screw  562  is rotated. 
       FIG. 6E  depicts attachment actuation device  600  being engaged. Attachment actuation device  600  has a first plate engager  600   a  and a second plate engager  600   b . First plate engager  600   a  and a second plate engager  600   b  each respectively utilize an optional adaptor  610   a - b  to engage first and second compression plates  310   a - b . Note that attachment actuation device  600 ′ described in reference to FIGS.  12 CA- 12 G does not utilize these optional adapters since its first and second plate engagers  600   a ′- 600   b ′ adapted to directly engage first and second compression plates  310   a ′- 310   b′.    
     First plate engager  600   a  and second plate engager  600   b  each have a cutter aperture  620   a  and  620   b . Cutter  400  extends through these aligned apertures  620   a - b . First plate engager  600   a  is positioned on rail  640  such that it extends slightly beyond cutting edge  414  of cutter  400 . This difference in length enables first compression plate  300   a  to be held slightly beyond cutter in a manner that permits the wall of vessel  20  to be pulled into compression plate apparatus as shown in  FIG. 6D-6E  and distended as needed. 
     Rail  640  is attached to body  710  via rail pin  642 . A groove pin  644  extends through rail  640  as described in greater detail below. A first plate engager pin  646  holds first plate holder  600   a  on the proximal end of rail  640 . 
     First plate engager  600   a  is fixedly mounted on rail  640  via pin  646  while second plate engager  600   b  is movably mounted on rail  640 . Second plate engager  600   b  has a groove  634  through which groove pin  644  extends. The configuration of groove pin  644  in groove  634  enables second plate engager  600   b  to be held in a fixed orientation such that it can be moved back and forth as needed with respect to first plate engager  600   a.    
     Second plate engager is moved on rail  640  by rotating threaded compressor sleeve  650  which engages a threaded rail sleeve  648 . Threaded rail sleeve  648  may be adhered onto rail  640  or be an integral component. Rail  640  and its threaded rail sleeve  648  or threaded rail portion combined with compressor sleeve  650  are means for advancing one plate engager towards the other plate engager. 
     First plate engager  600   a  has an adaptor  610   a  that preferably has two halves  612   a  and  614   a . As best seen in  FIG. 6C , when these halves are joined together, adaptor  610   a  has a proximal side configured such that there is a curvature from the perimeter inward to direct the engaging end  212  of anvil  210  into the aperture defined by the inner perimeter of adaptor  610   a . The distal side of adaptor  610   a  has a recess  616  adapted to the size of outer periphery  311   a  of first compression plate  310   a . Sets screws  615  lock first compression plate  310   a  in place by pushing against adaptor  610   a . Note that there are many other ways for locking first compression plate with first plate engager  600   a  such as the use of conventional quick release configurations. 
     Second plate engager  600   b  has an adaptor  610   b  or  610   b  as respectively shown in  FIGS. 5A-5B . Adapter  610   b  is integral while adapter  610   b ′ has halves  612   b  and  614   b . Either may be utilized, but when positioned on a graft vessel as shown in  FIG. 5B  that has reinforcements  57 , which may be any conventional reinforcements such as fluorinated ethylene-propylene (FEP) strands bonded onto a PTFE graft vessel, the reinforcements make it difficult to remove the adapter that it integral like adaptor  610   b . As best seen in  FIG. 5A , adaptor  610   b  is tubular to receive the vessel and has a flange  616   b  that extends around the tube and is sized to push against exterior side  324   b  of second compression plate  310   b . Apertures  618   b  are located in flange  616   b  that are oriented and sized to slidably receive guides  330  of compression plate apparatus  300 . Adapter  610   b  also has a flange with apertures so that it can fit over second compression plate  310   b  as shown in  FIG. 5B . These features are more clearly shown in  FIG. 6C  which provides a cross-sectional view of assembly  390  shown in FIG. in  FIG. 5B . Note that adaptor  610   b  is also shown in  FIG. 16C , which is a close-up view of the proximal portion of applicator  700 , however, adaptor  610   b  is pushed back from its position of engagement with second compression plate  310   b  in order to more clearly see other features of operator  700 . 
     As discussed below in the Side-to-Side Anastomosis section in reference to  FIG. 15A-15C , the attachment actuation device need not be part of the same apparatus with the anvil pull engager and the cutter.  FIGS. 15A-15C  show a device at  600   a ″ that is adapted to hold the first compression plate stationary as the anvil and the cutter are engaged. Device  600 ″ is also discussed below in reference to  FIGS. 15A-15C  which is used to approximate compression plates  310   a - b  by pushing second compression plate  310   b  on guides  330 . Attachment actuation device  600 ,  600 ′ and  600 ′″ are examples of attachment actuation means for actuating a compression plate assembly. In addition to device  600 ,  600 ′, and  600 ′″, device  600   a ″ is also an example of an attachment actuation device adapted to hold the first compression plate stationary as the anvil and cutting device are engaged to form an opening. 
     As noted above, compression plate apparatus  300 ,  300 ′,  300 ″ are examples of means for joining a portion of the first vessel that defines the first vessel opening to a portion of a second vessel that defines a second vessel opening. Accordingly, attachment actuation device  600  is more broadly an example of attachment actuation means for actuating means for joining a portion of the first vessel that defines the first vessel opening to a portion of a second vessel that defines a second vessel opening. 
     Other examples of attachment actuation means include mechanical, chemical or radiation-based attachment actuation means for actuating the anastomosis of the portion of the first vessel that defines the first vessel opening to the portion of the second vessel that defines the second vessel opening. Examples of mechanical attachment actuation means include a suturing device such as a needle and thread; and a stapling or clipping device such as device  800 . Examples of chemical attachment actuation means include a device such as device  400 ″ for delivering biocompatible adhesives or glue; solder; biological procoagulant solution; a combination of a chromophore and solder, and combinations thereof. Examples of radiation-based attachment actuation means include a device such as device  400 ″ for radiation welding, a device for laser sealing, and combinations thereof. As shown by device  400  and  800 , combinations of these attachment actuation means are also possible. 
     As mentioned, the attachment actuation device need not be part of the same apparatus with the anvil pull engager and the cutter. This reduces the size of the instruments utilized. The size of the instruments utilized may also be decreased through the elimination of some of the features of operator  700 . Operator  700  has the ability to modify its configuration in ways that enable it to be highly fine tuned to the parameters of a particular anastomosis procedure. Accordingly, it is highly useful in a research setting. However, applicators utilized in a commercial setting may have more standardized features that do not permit the same degree of modifications. For example, the spring biasing device may be preset to a standard setting. Use of such standard settings may assist in reducing the overall size of the operator. Note that the knobs and other features of external anastomosis operator that provide adjustments may also be achieved through other configurations that achieve these adjustments more rapidly. For example, instead of rotating compressor sleeve  650 , compression plate apparatus  300  may be compressed through a configuration that is trigger activated. 
     As indicated above, anvil  210  may be positioned under direct image guidance from a distant percutaneous puncture to the anastomosis site based upon a diagnostic angiographic s roadmap. A skin incision and limited vessel dissection is then performed at the anastomosis site to expose the vessel wall. Alternatively, the anvil may be externally positioned. In either event, once the anvil has been positioned such that it is against the interior of the vessel wall and the anvil pull extends from the vessel, then the anvil pull can be positioned in the operator  700  as shown in  FIGS. 6C-6D  for completion of the anastomosis procedure. 
     Side-to-Side Anastomosis 
       FIGS. 15A-15C  depict the primary steps involved in achieving a side-to-side anastomosis. Cutter  400  is positioned in a vessel  50  by inserting the cutter into an end of vessel  50  and then twisting cutter  400  in vessel  50  such that cutting knife  412  is oriented towards the wall of vessel  50  as shown in  FIG. 15A . Cutting knife  412  is prevented from cutting through the wall of vessel  50  by a sheath  490 . Sheath  490  is positioned relative to cutter  400  such that the distal end  492  of sheath  490  extends beyond cutting edge  414 . This configuration prevent cutting edge  414  from contacting vessel  50  until sheath  490  is pulled upward away from the anastomosis site. 
     Two separate instruments perform the task of attachment actuation device  600 . First plate engager  600   a ″ comprises tongs or pliers that have opposing grasping portion  602   a ″ that extend integrally from pivotally attached handle portions  604   a ″. Grasping portions  602   a ″ are adapted to lock onto first compression plate  310   a  so that anvil  210  can be pulled through first compression plate opening  320   a  and distend the wall of vessel  20  into compression plate apparatus  300 . 
     While first plate engager  600   a ″, holds first compression plate  310   a  cutter  400 , sheath  490  and vessel  50  are pushed through second compression plate opening  320   b . Note that anvil pull  230  extends through the wall of vessel  50  and through chamber  420  of cutter  400 . As cutter  400  is pushed through compression plate apparatus  300  and contacts anvil  230 , sheath  490  is retracted. 
       FIG. 15B  shows sheath  490  retracted so that cutter  400  and anvil  210  can engage each other such that openings  24  and  54  are simultaneously made respectively in vessel  20  and in vessel  50 . After opening  54  is made, the portion  56  defining second vessel opening  54  rests on either sheath  490 , cutting tube  410  or anvil  210 . As the compression plates are brought together, portion  56  is advanced onto landing  214  against portion  26  of vessel  20  that defines first vessel opening  24 . 
       FIG. 15B  shows first and second compression plate apparatus being grasped by attachment actuation device  600 ′″. More particularly, attachment actuation device  600 ′″ has a first plate engager  600   a ′″ that engages first compression plate  310   a  and a second plate engager  600   b ′″ that engages first compression plate  310   b  such that the compression plates  310   a - b  can be approximated by pushing second compression plate  310   b  on guides  330 . 
       FIG. 15C  depicts attachment actuation device  600 ′″ after it has pushed second compression plate  310   b  to first compression plate  310   a . As second compression plate  310   b  is pushed toward first compression plate  310   a , portion  56  of vessel  50  pushes against portion  26  of vessel  20  as these portions rest on landing  214  which causes the portions to respectively curl onto holding tabs  314   a - b . When the second compression plate  310   b  is fully pushed into position by attachment actuation device  600 ′″ then portions  26  and  56  are everted as shown on holding tabs  314   a - b . Cut portions  25  and  55  remain on spherical engaging end  212  of anvil  210  and are removed with anvil apparatus  200 , cutter  400  and sheath  490  through vessel  50 . 
     It follows from the illustrations and the foregoing discussion that the compression plates of this invention can effectively be used for anastomoses at the end of tubular structures. This implementation of the teachings described above to end-to-end anastomosis simply requires ordinary skills in the art. 
     Externally Directed Anastomosis 
     Intraluminal access to the anastomosis site in the receiving blood vessel can be impeded by an occlusion or by blood vessel damage. In this case, a catheter cannot be used to intraluminally access the anastomosis site. Instead, other embodiments of this invention rely on the intraluminal access to the anastomosis site through a small incision, such as an arteriotomy, made at the anastomosis site. The anvil apparatus is then inserted through such incision and the abutting of the receiving blood vessel from its intraluminal space is then performed in the same way as when the anvil and wire are inserted with the aid of a catheter. 
       FIGS. 16A-16E  depict the primary steps involved in creating an anastomosis through the use of an externally positioned anvil apparatus in combination with an external anastomosis operator.  FIG. 16A  depicts an insertion opening  16  that has been made in vessel  20 . Insertion opening  16  is preferably just large enough to permit an anvil such as anvil  210   c  as shown in  FIG. 7C  or any of the other anvils disclosed herein to be externally positioned into lumen  28 . After anvil  210   c  has been inserted though a wall of first vessel  20  at insertion opening  16  that has been selected as an anastomosis site such that anvil pull  230  extends through insertion opening  16 , then a stay suture  30  or several stay sutures may alternatively be used to partially close insertion opening  16 . 
     As discussed above, in relation to  FIG. 7D , it may be easier to insert an anvil extraluminally that has a tapered terminal end  218  such as terminal end  218   c  of anvil  210   c  or terminal end  219   c  of anvil  210   d . Note that  FIGS. 16C-16E , however, show an anvil  210  that has been inserted from outside of vessel  20  that has a nontapered terminal end  218 . 
     As shown in  FIG. 16C , anvil pull  230  can then be loaded into external anastomosis operator  700  for the anastomosis procedure. Note that once anvil pull  230  is loaded into external anastomosis operator  700  then the remainder of the procedure is the same as the anastomosis procedure outlined above in reference to an intraluminally positioned anvil apparatus. 
       FIG. 16D  depicts anvil pull  230  extending through compression plate apparatus  300  and into chamber  420  of cutter  400  such that cutting edge  414  self centers and seats on spherical engaging end  212  of anvil  210  just as is shown in  FIG. 4A  which depicts the use of an intraluminally positioned anvil apparatus. The only difference between the  FIG. 4A  and  FIG. 16D  is that initial piercing  15  is significantly smaller than insertion opening  16 . Stay suture  30 , however, enables anvil  210  to distend the wall of vessel  20  since stay suture  30  reduces the size of insertion opening  16 . 
       FIG. 16E  shows that it is possible to complete the same step shown in  FIG. 16D  without a stay suture  30  as long as the distension of the wall of vessel  20  does not cause insertion opening  16  to increase in size such that it becomes so large that a part of it is beyond the reach of cutting edge  414  of cutter  400 . Accordingly, when distending a vessel that has an insertion opening  16  from an extraluminally positioned anvil instead of a relatively small initial piercing  15  from an anvil pull of an intraluminally directed anvil apparatus, it may not be possible to distend the vessel to the extent that is possible with an intraluminally directed anvil apparatus. For this reason landing  214  of anvil  210  shown in  FIG. 16E  is shorter than landing  214  of anvil  210  shown in  FIG. 4A  and in  FIG. 16E . 
     Another method for enabling the wall of the vessel to be distended for the subsequent eversion process to occur in the desired manner involves the minimization of the size of insertion opening  16  through the use of expandable anvils. As discussed above in the Anvil section, anvils may be utilized that are expanded or deployed at the anastomosis site. For example  FIGS. 9A-9B  and  FIGS. 10A-10B  depict mechanically deployable anvils while  FIGS. 11A-11B  depict chemically deployable anvils. These same expandable anvils may be inserted through a small insertion opening from the exterior of the vessel into the lumen and then be deployed. Accordingly, such expandable anvils have an initial collapsed position for insertion into the insertion opening and an expanded position. Once the anvil has been deployed then it can be used like solid or rigid anvils. 
     Just like the anvils that are intraluminally directed, anvils that are externally positioned into the lumen of a vessel preferably have an engaging end that is larger than cutter  400  such that portions of the engaging end  212  of the anvil extend beyond the cutting edge  414  when the cutter  400  or other cutting device engages the anvil and forms the first vessel opening. Stated otherwise, the cross-sectional area defined by the perimeter of cutting edge  414  of the cutting knife  412  is smaller than a cross-sectional area of the engaging end  212  at which cutting edge  414  engages engaging end  212 . So for an expandable anvil, its engaging end preferably has a greater cross-sectional area than the cross-sectional area defined by cutting perimeter of the cutting device when in the expanded position. Also, the engaging end is also spherical such that cutter self seats and self centers on spherical engaging end  212 . The advantages of these configurations are discussed in detail above in the Anvils section. 
     Note that as shown by  FIGS. 18A-18B , externally positioned anvils may be used to form noncircular openings. These anvils have an engaging end with a shape corresponding to that of the cutting edge of a cutter such that the first vessel opening is formed as the noncircular cutting edge presses against the engaging end. 
     Externally Positioned Anastomosis Fenestra Cutting Apparatus. 
     As indicated above, the anvil is preferably sized at its engaging end to have a greater cross-sectional area than a cross-sectional area defined by the perimeter of the cutting edge of the cutting device such that portions of the engaging end of the anvil extend beyond the cutting edge when the cutting device engages the anvil and forms the first vessel opening. This size differential can be utilized in an apparatus adapted only to make vessel openings. 
       FIG. 17A  is a perspective view of an externally positioned anastomosis fenestra cutting apparatus  1000  having an anvil  1210  ready for insertion through an insertion opening  16  into the lumen of a blood vessel.  FIG. 17B  is a perspective view of cutting apparatus  1000  distending vessel  20  and being readied for cutting.  FIG. 17C  shows the formation of an opening  25  as cylindrical cutting edge  1414  engages spherical engaging end  1212 . 
     Cutting apparatus  1000 ′ is shown in  FIGS. 18A-18B  with an elliptical anvil  1210 ′ adapted to form elliptical openings in vessel  20  with elliptical cutting device  1400 ′. Note that  FIG. 18A  shows cutting apparatus  1000 ′ distending the wall of vessel at angle so that the 11 elliptical opening formed by a cutting apparatus  1000 ′ is properly oriented for a Y-type end-to-side anastomosis. Cutting apparatus  1000 ′ is a simple device that has a stationary cutter that cuts the blood vessel when the anvil is pulled against the cutter. Note that while anvil and anvil pull are shown as being integral, the anvil of the cutting apparatus may also be an expandable anvil such as those discussed in the section entitled Anvils. 
       FIGS. 19A-19B  provide a cross-sectional views of cutting apparatus  1000  which reveal that it is spring biased. Spring biased cutting apparatus  1000  has a handle  1010  that includes a stem  1012  and a handle cap  1014 . Stem  1012  travels within a chamber as shown by comparing  FIGS. 19A-19B  to push against a high tension spring  1016  that pushes against a cutter  1400 . While cutter  1400  is movable, anvil pull  1230  moves a greater distance in order to contact cutter  1400 . 
     A pin  1020  extends through anvil pull  1230  and casing  1022  such that movement of grasping handle  1024 , which is an integral component of casing  1022 , also moves anvil pull  1230 . Pin  1020  travels within a groove  1018  as shown in phantom lines in  FIGS. 17A-17B . The distal end of anvil pull  1230  abuts a low tension spring  1026  concentrically positioned within high tension spring  1016 . This configuration enables anvil pull  1230  and cutter  1400  to both be spring biased. 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.