Abstract:
A method of identifying vasculature comprising the steps of introducing an indicator in a peripheral vessel, and advancing a portion of the indicator into an internal vessel to identify said vessel. A catheter for identifying vasculature is also disclosed. The catheter is adapted to be introduced into a peripheral vessel and a portion thereof advanced into an internal vessel. The catheter comprises a light delivery portion at a distal end thereof and an expandable member located proximal to the light delivery portion.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to methods and devices for facilitating surgical procedures, and more particularly to methods and devices for transilluminating an internal blood vessel, artery or vein within a patient during a cardiac surgery procedure to facilitate locating and manipulating the vessel, artery or vein.  
         BACKGROUND OF THE INVENTION  
         [0002]    Minimally invasive surgical techniques have revolutionized cardiac surgery. Minimally invasive cardiac surgery enjoys the advantages of reduced morbidity, quicker recovery times, and improved cosmesis over conventional open-chest cardiac surgery. Recent advances in endoscopic instruments and percutaneous access to a patient&#39;s thoracic cavity have made minimally invasive surgery possible. Reduction in morbidity, lower cost, and reduced trauma has made minimally invasive surgery desirable.  
           [0003]    However, many problems and controversies still surround the viability of minimally invasive cardiac surgical procedures. One such problem is the difficulties of locating and manipulating small vessels, arteries, or veins in a closed-chest, blind environment during, for example, a minimally invasive coronary artery bypass graft (CABG) procedure. The coronary arteries typically have a diameter in the range of between about 1 to 5 mm, and the coronary bypass graft vessels have a diameter on the order of about 1 to 4 mm for an arterial graft such as a thoracic artery  56 , or about 4 to 8 mm for a vein graft such as a saphenous vein  84 . Locating and manipulating these tiny vessels is sufficiently difficult in conventional open-chest cardiac surgical procedures, and is made substantially more difficult in closed-chest, less invasive mini-thoracotomy procedures and in minimally invasive endoscopic procedures where the cardiac surgeon may not be able to view these vessels directly. Endoscopic instruments are currently used by the cardiac surgeon to view the internal thoracic cavity during a minimally invasive surgical procedure, but the use of these instruments alone has inherent drawbacks. For example, it is often difficult to differentiate the often tiny coronary arteries or coronary bypass graft vessels from other surrounding vessels and tissues with the use of endoscopic instruments alone during a minimally invasive surgical procedure.  
           [0004]    An alternative technique for performing minimally invasive cardiac surgery procedures, therefore, is needed which facilitates locating and manipulating vessels by illumination from within the vessels. The technique should employ transillumination of a coronary vessel or coronary bypass graft vessel with light at predetermined wavelengths that are not substantially absorbed by the vessel itself, blood, other bodily fluids, or surrounding tissues and the like. The surgical technique can be applied for example, to the following areas, although it is to be understood that the present invention is by no means limited to these specific cardiac surgery procedures: (1) dissecting a left (or right) internal thoracic artery (LITA or RITA) from the chest wall in preparation for anastomosing the LITA to a native coronary vessel in a CABG procedure; (2) locating the LITA graft in a CABG repeat procedure; (3) locating the coronary artery to which a coronary bypass graft vessel is to be anastomosed; and (4) harvesting a free graft vessel, such as a saphenous vein, in preparation for anastomosing the free graft vessel to a native coronary artery in a CABG procedure. Each of these procedures will be explained in greater detail hereinafter.  
           [0005]    Transillumination within the body of a patient has been recognized for at least a century. As long ago as the mid-1800&#39;s, British physicians began detecting scrotal cancer by holding a lamp behind the testes and noting the shadows the tumors cast. See “Transillumination: Looking Right Through You,” Science, Vol. 261, Jul. 30, 1993 at page 560. Transillumination of the stomach was reported as early as 1911. Intraoperative transillumination of the small intestine and colon also is generally well known. See, e.g., Ambartsoumian, A., “Infrared Transillumination Gastroscopy,” Gastrointestinal Endoscopy 1995:41(3):270-71. Illuminators for transilluminating internal organs or vessels have been used in the fields of urology and gastroentology. An illuminator placed in the urethra or esophagus facilitates laproscopic and cystoscopic procedures by illuminating these organs thus avoiding unwanted damage to the organs. See, e.g., U.S. Pat. No. 5,624,432 to Angelchik (describing the preferred use of an illuminated bougie for illuminating the esophagus). Transillumination has also been used to facilitate the proper intracorporeal placement of catheters. See, e.g., U.S. Pat. No. 5,370,640 to Kolff, which discloses the use of a fiberoptic stylet device for facilitating the intracorpoeal placement of a retrograde coronary sinus catheter into the coronary sinus of a heart of a patient.  
           [0006]    Although illuminators are generally well known by those skilled in the art, they typically have application for diagnostic or therapeutic purposes. Examples of such devices include the illuminators disclosed in U.S. Pat. No. 5,169,395 to Narciso, Jr., U.S Pat. No. 5,196,005 to Doiron et al., U.S Pat. No. 5,269,777 to Doiron et al., U.S Pat. No. 5,330,465 to Doiron et al., U.S Pat. No. 5,441,497 to Narciso Jr., and U.S Pat. No. 5,454,794 to Narciso, Jr. et al. The devices described in those patents generally have the ability to deliver light to luminal surfaces such as blood vessels and are typically used for the diagnosis and treatment of a variety of medical conditions, with particular application to performing photodynamic therapy (PDT) in the treatment of diseased tissue such as tumors, inducing hyperthermia, or performing both percutaneous and intraoperative phototherapy of cardiovascular disease. However, despite the fact that transillumination has long been known, the present invention is believed to be the first use of transillumination to facilitate CABG surgery by any one of the methods described below.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention discloses methods and devices for identifying vasculature. The identification methods and devices described herein can be used in conjunction with a combined technique involving laparoscopy and endoscopy to facilitate viewing and manipulating internal vessels during CABG and other cardiac surgery procedures. The techniques of the present invention can be used in open-chest coronary surgery where a partial or median sternotomy is used to gain access to the heart, in closed-chest less invasive coronary surgery procedures where a mini-thoracotomy is used to gain access to the heart, or in totally endoscopic procedures where a series of small holes, or ports, in the chest wall are used to gain access to the heart.  
           [0008]    A method of the present invention is for identifying vasculature and generally comprises the steps of introducing an indicator in a peripheral vessel and advancing a portion of the indicator into an internal vessel to identify the vessel.  
           [0009]    In another aspect of the invention, a catheter for identifying vasculature is adapted to be introduced into a peripheral vessel and a portion thereof advanced into an internal vessel. The catheter generally comprises a light delivery portion at a distal end thereof, and an expandable member located proximal to the light delivery portion.  
           [0010]    In yet another aspect of the invention, a system for delivering energy to an internal vessel of a patient generally comprises a catheter and a catheter guide. The catheter comprises a flexible, elongated shaft having a proximal end, a distal end, and an energy transmitting diffuser located at the distal end of the shaft. The catheter guide has an opening which is sized and dimensioned to permit the catheter to be inserted longitudinally within the guide. The guide is configured for introduction into the peripheral vessel and advancement to the internal vessel to facilitate delivery of the catheter into the internal vessel.  
           [0011]    Additional features and advantages of the invention will be set forth in or are apparent from the detailed descriptions of the preferred embodiments found herein below. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a schematic illustration of the transillumination catheter of the present invention.  
         [0013]    [0013]FIG. 2 is a longitudinal cross-sectional view of a distal end of the transillumination catheter of FIG. 1.  
         [0014]    [0014]FIG. 3 schematically illustrates insertion of the transillumination catheter into a brachial artery  48  of a patient for advancement to a left internal thoracic artery  56  via a left subclavian artery  90 .  
         [0015]    [0015]FIG. 4 is an enlarged view of a patient&#39;s heart schematically showing the transillumination catheter disposed within a subclavian artery and being advanced towards the left internal thoracic artery.  
         [0016]    [0016]FIG. 5 is an enlarged view of a patient&#39;s heart schematically showing the transillumination catheter disposed within a subclavian artery and being advanced towards the left internal thoracic artery in a repeat CABG procedure.  
         [0017]    [0017]FIG. 6 is an enlarged view of a patient&#39;s heart schematically showing the transillumination catheter disposed within a stenotic coronary artery.  
         [0018]    [0018]FIG. 7 schematically illustrates insertion of the transillumination catheter of FIG. 1 into a saphenous vein of a patient for illumination of the vein prior to harvesting it for a coronary anastomosis procedure, along with showing other vessels which can be illuminated.  
         [0019]    [0019]FIG. 8 is a schematic diagram of an alternative embodiment of the transillumination catheter of FIG. 1.  
         [0020]    [0020]FIG. 9 shows the transilluminator catheter device of FIG. 8 positioned within a LITA graft vessel which has an anastomotic fastener positioned about an external surface of a free end portion of the graft vessel.  
         [0021]    [0021]FIG. 10 shows the free end portion of the graft vessel everted over a portion of the anastomotic fastener.  
         [0022]    [0022]FIG. 11 shows the graft vessel with the transillumination catheter of FIG. 8 positioned therein being inserted into the target vessel through an incision in the target vessel.  
         [0023]    [0023]FIG. 12 is an elevated view of the anastomotic fastener following light irradiation and radial expansion of a balloon of the transillumination catheter.  
         [0024]    [0024]FIG. 13 is an elevated view of the anastomotic fastener after the transillumination catheter has been removed from the graft vessel showing the completed anastomosis.  
         [0025]    [0025]FIG. 14 is a schematic diagram of an alternative embodiment of the transillumination catheter of FIG. 1.  
         [0026]    [0026]FIG. 15 is a schematic illustration of a catheter guide and guide wire for facilitating placement of the transillumination catheter into an internal vessel. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0027]    Referring now to the drawings, and first to FIG. 1, an indicator for identifying vasculature is shown and is generally indicated by the reference numeral  10 . The indicator  10  of the present invention is useful for delivering energy, such as visible, infrared, or ultraviolet light energy, to within a vessel, artery or vein during a coronary surgery procedure, such as a CABG procedure, to illuminate the vessel, artery or vein. Such transillumination of an internal vessel facilitates locating and manipulating the vessel during the surgical procedure. The indicator  10  can be used to facilitate open-chest coronary surgery procedures, closed-chest less invasive mini-thoracotomy surgery procedures, and totally endoscopic minimally invasive procedures.  
         [0028]    The indicator  10  comprises a transillumination catheter having a light delivery portion for transmitting light to identify a vessel. The light is preferably diffused over a section of the distal end of the catheter  10  to sufficiently illuminate the vessel. The catheter  10  includes a fiber optic connector  23  at a proximal end of the catheter which is in optical communication with an energy source (not shown), such as a laser or a broad-band light source. In the latter case, a wavelength of between about 400 and 700 nm, and more preferably between about 600 and 700 nm, is preferred since this range of wavelengths will facilitate the emitted light energy to pass through bodily tissue. The fiber optic connector  23  can also be optically connected to an ultraviolet or infrared light energy source. Ultraviolet light typically has a wavelength of between about 100 and 400 nmn and infrared light typically has a wavelength of between about 700 and 15,000 nm. The light from the light is delivered to a single optical fiber or bundle of optical fibers  25  enclosed within a first, inner catheter sheath  21 . The optical fiber or bundle of optical fibers  25  is contained within and extends the length of the catheter  10  from the fiber optic connector  23  to the distal portion of the catheter  10  proximal to the light diffusing end member  14  of the catheter.  
         [0029]    The catheter  10  includes a Y-shaped adapter  20  towards its mid-portion which is in fluid communication with an opaque, outer catheter sheath  18  which terminates at the proximal face of light diffusing end member  14 . Inner catheter sheath  18  is sufficiently flexible to navigate tortuous vessels without great difficulty, and is preferably made from one or more biocompatible thermoplastic materials which have the optical and thermal properties required for this device to be operable such as Teflon®, polyurethane, polyethylene, polyethylene terephthalate, or other suitable biocompatible materials or combinations thereof.  
         [0030]    The Y-shaped adapter  20  includes a balloon inflation/deflation port  22  through which a fluid may be administered and fluidly communicated through an inflation/deflation channel  30  (see FIG. 2) created between the external sheath  18  and inner sheath  21  to the balloon  16 . The distal end of the transillumination catheter  10  includes a light diffusing end member  14  which is optically coupled to the distal face of optical fiber  25 . The light diffusing end member  14  is marked by a pair of radiopaque markers  13  for visualization of the catheter  10  under x-ray fluoroscopy. Radiopaque markers  13  can be fabricated from gold, platinum, platinum-iridium, or any one of a number of other relatively dense materials. The distal portion of the catheter  10  is curved as shown to provide steering capabilities through a vessel which obviates the need for a distal guidewire or an internal steering wire or other steering mechanism. The shape of the distal portion of the catheter can be set thermally during processing or an additional coil (not shown) can be placed into the distal portion of catheter  10  as is well known by a person of ordinary skill in the art.  
         [0031]    The transillumination catheter  10  is preferably dimensioned and configured for introduction into a peripheral vessel, such as a brachial or radial artery  51  of a patient, and advanced to an internal thoracic artery of the heart (i.e., the LITA) through a subclavian artery (i.e., the left subclavian artery  90 ). This will generally require a catheter length of between about 20 to 60 cm. In addition, the catheter  10  may be configured to be inserted directly into a vein graft, such as a sapahenous vein, for illuminating the vein graft, in which case the catheter  10  will have a similar length of between about 20 to 60 cm. Alternatively, the catheter  10  may be adapted for introduction into a femoral artery  82  and advancement to a coronary or other vessel, such as an internal thoracic artery for example, wherein the catheter will need to be longer in length, for example about 90 to 120 cm. The catheter  10  may be adapted for introduction into several coronary arteries and other vessels, such as a right coronary artery  60 , a left main coronary artery  58 , a left anterior descending artery  64 , a left circumflex  62 , an aorta  56 , a proximal coronary artery, including any branches thereof, from the same or other peripheral vessels such as a radial artery  51 , left carotid artery  52 , right carotid artery  54 , brachial artery  48 , subclavian artery  90 , or femoral artery  82 , in which case its length will vary depending on the particular vessel and route of administration chosen. (See FIGS.  3 - 7 ).  
         [0032]    Referring now to FIG. 2, a longitudinal cross-sectional view of the distal end of the transillumination catheter  10  is shown. As seen in FIG. 2, optical fiber (or bundle of optical fibers)  25  is circumferentially surrounded by cladding  27  which promotes complete internal reflection of the light transmitted down the core of optical fiber  25 . The distal portion of the cladding  27  is surrounded by an optical fiber centering sleeve  29 . The light is transmitted from the distal face of optical fiber  25  to the light diffusing medium  15  encased within light diffusing end member  14 . Light diffusing medium  15  is fabricated from an optically clear substrate such as silicone with optical scattering centers distributed within the substrate. The optical scattering centers can be fabricated from alumina, silica, titanium oxide, calcium carbonate, or other suitable materials. By varying the concentration of scattering centers in the light diffusing medium  15  from lowest at the optical fiber  25  to greatest at the rounded cap  12 , as shown, either discretely or continuously, the light output distribution from the light diffusing end member  14  can be made both radially and axially uniform. Alternatively, the optical scattering centers can be uniformly distributed throughout light diffusing medium  15 .  
         [0033]    The transillumination catheter  10  shown in FIGS.  1 - 2  can be used in any one of several novel ways to facilitate locating and manipulating vessels, arteries or veins in coronary surgery procedures. FIG. 4 shows one such novel use of transillumination catheter  10  for locating and illuminating a LITA graft vessel  46  prior to dissecting the LITA graft from the chest wall in preparation for a CABG procedure. The LITA transillumination technique can be used in open-chest coronary surgery where a partial or median sternotomy is used to gain access to the heart or in closed-chest less invasive coronary surgery procedures where a mini-thoracotomy is used to gain access to the heart The harvest of the LITA  46  (or RITA  45 ) for coronary bypass grafting can also be performed thoracoscopically through three small skin incisions as fully described in Duhaylongsod, F.G. M.D., Mayfield, W.R. M.D., Wolf, R.K. M.D., “Thoracoscopic Harvest of the Internal Thoracic Artery for Coronary Bypass Grafting: A Multicenter Experience in 219 Cases,” presented at the “Facts &amp; Myths of Minimally Invasive Cardiac Surgery: Current Trends in Thoracic Surgery IV” symposium before the 34 th  Annual Meeting of the Society of Thoracic Surgeons, New Orleans, LA, Jan. 24, 1998, the entire contents of which are incorporated by reference herein. The following is an exemplary usage of the LITA transillumination technique in a standard mini-thoracotomy procedure.  
         [0034]    A transillumination catheter, such as catheter  10  in FIGS.  1 - 2 , is first percutaneously inserted into a peripheral vessel, such as a brachial artery  48 , by conventional means and advanced with the aid of x-ray fluoroscopy into the LITA  46  via a subclavian artery to provide illumination of the LITA, as schematically illustrated in FIGS.  3 - 4 . As noted above, the catheter  10  can also be percutaneously inserted into other peripheral vessels as well, such as a radial artery  51  or a femoral artery  82 , by a suitable technique, such as the Seldinger technique, and advanced through a subclavian artery into the LITA (or other coronary vessel). Applicants have demonstrated that the use of a transillumination catheter placed within the LITA helps to facilitate the procedure of locating, manipulating and dissecting the LITA from the chest wall without damage or unnecessary morbidity to the surrounding tissues and body structures.  
         [0035]    After establishment of general anesthesia with a double-lumen endobronchial tube, for example, allowing complete collapse of the left or right lung, the left lung is deflated to allow access to the heart and LITA. A 6 to 8 cm left anterior thoracotomy incision is then made in the patient&#39;s chest in the fourth intercostal space. Other sites may be suitable depending on the patient&#39;s anatomy, such as the fifth or sixth intercostal space. A retractor is used to spread apart the ribs to provide access to the heart and the LITA. The LITA is then dissected under direct vision with suitable instruments introduced through the thoractomy incision, such as scissors, pliers and the like. The balloon  16  of catheter  10  is used to internally seal the LITA graft vessel prior to transecting the distal end of the LITA graft in preparation for the coronary anastomosis procedure. This obviates the need for using external clamps to provide hemostasis within the graft vessel prior to transection. Following dissection of the LITA, the resulting LITA pedicle is transected with a suitable instrument such as scissors through the thoracotomy. Papaverine is then injected directly through the LITA, which is prepared for coronary anastomosis to a stenotic coronary artery  64 . The anastomosis of the LITA to the coronary artery is then performed directly through the thoracotomy incision by using conventional suturing means, or by using a novel distal anastomosis device and procedure such as described below in connection with FIGS.  8 - 13  and in co-pending patent application for Anastomosis Device and Method, filed on Mar. 9, 1998, and invented by Hugh Narciso, Jr.  
         [0036]    If required, cardiac stabilization such as described in co-pending provisional patent application, Ser. No. 60/055,127, for Compositions, Apparatus and Methods for Facilitating Surgical Procedures, filed Aug. 8, 1997, and invented by Francis G. Duhaylongsod, M.D., may be used during the procedure. Other pharmacological or mechanical methods may also be used.  
         [0037]    A second preferred intended novel use of the present invention is for locating the LITA, for example, in a repeat coronary surgical procedure, such as in a redo CABG procedure, to prevent injury while attempting to correct an imperfect anastomosis graft between the LITA and a stenotic native coronary artery, such as the LAD. As noted above, locating the LITA during repeat CABO surgery, for example, is critical to the safety of the patient because the graft LITA represents one of the major supplies of blood to the heart. When the LITA is anastomosed to the LAD, for example, it typically is placed across the anterior surface of the heart, directly under the sternum, as shown in FIG. 5. If a second, or redo, CABG procedure needs to be performed, the cardiac surgeon typically needs to bisect the sternum to gain access to the heart. Often in doing so, the surgeon inadvertently compromises the LITA graft  70  and the patient has limited alternatives if the LITA graft cannot be repaired.  
         [0038]    To alleviate this concern, as described above, a transillumination catheter, such as catheter  10  in FIGS.  1 - 2 , is percutaneously inserted into a peripheral vessel, such as a brachial artery  48  or radial artery  51 , and advanced into the LITA  46  via a subclavian artery  40  to provide illumination of the LITA, as schematically illustrated in FIG. 5. We have demonstrated that light diffusing from a transillumination catheter at a specific wavelength or wavelengths (for example, at a wavelength of between about 400 and 700 nm, and more preferably between about 600 and 700 nm) which is placed within the lumen of the LITA graft vessel is completely visible through the chest wall of the patient. With a transilluminator catheter in place and the LITA graft  46  illuminated, using current techniques, a surgeon can accurately perform a partial or median sternotomy to gain access into the patient&#39;s thoracic cavity while avoiding the illuminated LITA graft vessel, thus obviating difficulties associated with a compromised LITA graft  46 . A partial or median sternotomy is a procedure by which a saw or other appropriate cutting instrument is used to make a midline, longitudinal incision along a portion or the entire axial length of the patient&#39;s sternum, allowing two opposing sternal halves to be separated laterally. A large opening into the thoracic cavity is thus created, through which a surgeon may directly visualize and operate upon the heart to correct the imperfect anastomosis or diseased graft vessel.  
         [0039]    Another preferred intended novel use for the present invention is for locating and manipulating stenotic coronary vessels to which a graft vessel is being anastomosed in a CABG procedure. When performing CABG surgery, the stenotic native coronary artery to which a graft vessel is being anastomosed is obscured by surrounding fat or cardiac tissues. The cardiac surgeon must cut through tissues to access the coronary artery for purposes of creating a clear field of view to perform the anastomosis procedure. In some instances, it is possible for the cardiac surgeon to compromise the stenotic coronary artery  64  while attempting to cut through the fat and cardiac tissues. However, with a transilluminator catheter in place within the coronary artery, the cardiac surgeon will be able to dissect the surrounding tissues from the coronary artery thus exposing the artery for the anastomosis procedure. In this preferred use of catheter  10 , the catheter  10  is percutaneosuly inserted into a peripheral vessel, such as a brachial or radial artery  51 , as schematically illustrated in FIG. 6. Illumination of the transillumination catheter  10  will help the surgeon to visualize the stenotic coronary artery  64  while the graft vessel, such as the LITA pedicle  46  shown in FIG. 6, is being anastomosed to it.  
         [0040]    [0040]FIG. 7 schematically illustrates another preferred novel use of the transillumination catheter  10  of the present invention for harvesting a free vessel graft, typically a saphenous vein  84 , from a patient undergoing a CABG procedure. FIG. 7 illustrates the location of various vessels, including the abdominal aorta  74 , the common iliac artery  76  and the femoral vein  80 . A transilluminator catheter  10  is percutaneously inserted under the skin and inserted into a saphenous vein  84 . With the transilluminator in place and the saphenous vein  84  illuminated, a surgeon gently dissects the saphenous vein  84  with suitable surgical instruments, such as scissors and the like. The device may be used to transilluminate other bypass graft vessels such as a gastroepiploic artery  72  or an inferior epigastric artery  78 . The use of a transillumination device placed within the vein to be harvested makes the harvesting procedure simpler and facilitates location and extraction of the graft vessel. The transillumination catheter can be used in combination with conventional endoscopic techniques to simplify the process of harvesting the vein graft in an endoscopic procedure.  
         [0041]    [0041]FIG. 8 illustrates an alternative embodiment of the transillumination catheter  10  of FIGS.  1 - 2  generally indicated by reference numeral  100 , wherein like numerals represent like parts. For example, the optical fiber  25 , fiber optic connector  23 , catheter sheath  21 , and light diffusing end member  14  have the same general function and arrangement as described in FIGS.  1 - 2 . Transillumination catheter  100  can be used to facilitate the coronary surgical procedures described above akin to catheter  10 , and can also be used to facilitate joining a transected graft vessel to a stenotic target vessel in a coronary anastomosis, as will be described in greater detail below.  
         [0042]    As shown in FIG. 8, the Y-adapter  20  of catheter  10  is replaced with a three arm adapter  40  which incorporates two separate and independent balloon inflation/deflation ports  42 ,  44  which allow the addition of fluid, such as saline, through an inflation/deflation channel (not shown) defined by outer sheath  18 ′ to the distal balloons  16 ′ and  50 , respectively. Balloon  50  is affixed to the outer sheath  18 ′ so that the balloon  50  overlies a substantial portion of the light diffusing end member  14  of catheter  100 . The wall of the balloon  50  is transparent at the wavelength of light being delivered to (or received from) the surrounding tissue from light diffusing end member  14 . Distal and proximal to balloon  50  are radiopaque marker bands  13 ′ for visualization under x-ray fluoroscopy. The provision of a second balloon  50  is advantageous where the transillumination catheter  100  of the present invention is used in connection with a novel distal anastomosis device disclosed in co-pending patent application for “Anastomosis Device and Method,” filed on Mar. 9, 1998, and sharing a common inventor (Hugh L. Narciso, Jr.), the entire contents of which are fully incorporated by reference herein.  
         [0043]    As described therein, an anastomotic fastener is disclosed which in one embodiment comprises a tubular sleeve formed of a deformable material, such as a light-activated polymeric material (i.e., a polycaprolactone material) which becomes formable (i.e., fluent) upon the application of light energy to the material at a specific frequency, wavelength or wavelengths. The anastomotic fastener is configured to be positioned radially adjacent a free end portion of a graft vessel, such as a LITA graft, which is then preferably everted over a portion of the tubular sleeve. The deformable material may be selectively irradiated and molded in vivo by providing an energy that produces radiation at a frequency, wavelength, or wavelengths that are readily absorbed by the material. Radial expansion of the graft vessel will permit the deformable material in its moldable state to be shaped such that the free end portion of the graft vessel in its everted configuration is in secure conforming engagement with an inner wall of the target vessel, resulting in an intima-to-intima anastomosis. Transillumination catheter  100  can be used in lieu of the light-diffusing catheter described in the subject co-pending patent application to irradiate and radially expand the anastomotic fastener device.  
         [0044]    For example, with reference to FIGS.  9 - 13 , transillumination catheter  100  is first inserted into a LITA graft vessel  110  in a similar fashion as described above in connection with FIGS.  3 - 4 , and the LITA graft vessel  110  can be illuminated and then dissected and transected using balloon  16 ′ to seal the LITA prior to transecting it. With a free end portion of the LITA graft vessel  110  exposed as shown in FIG. 9 and balloon  16  expanded to occlude the vessel, a deformable anastomosis fastener device  120  can be positioned about an external surface of (or inserted into) a free end portion of the LITA graft  110 , which preferably is then everted over a portion of the tubular sleeve  120  (see FIGS.  9 - 10 ). The LITA graft vessel  110  is then inserted into a target vessel  112 , such as an LAD having a stenotic region  113 , through an incision in a wall of the target vessel  112 .  
         [0045]    With the anastomotic fastener  120  securely positioned in the target vessel  112 , light energy at a given wavelength or wavelengths is supplied to the light diffusing end member  14  of catheter  100  from the energy (not shown) via optical fiber  25  to irradiate, or illuminate, the tubular member  120  with light at a wavelength or wavelengths at which the deformable material readily absorbs. Upon absorption of the light energy, the deformable material forming tubular member  120  is transformed into its moldable, fluent state. Inflation of the balloon  50  causes the tubular member  120  to radially expand outwardly, thereby pressing the LITA graft vessel  110  into conforming engagement with an inner wall of target vessel  112  (see FIG. 12). If it is necessary to move catheter  100  longitudinally within the graft vessel  110  to, for example, precisely position balloon  50  radially adjacent tubular member  120 , balloon  16 ′ can be deflated slightly. This will permit longitudinal movement of the catheter  100  within the graft vessel  110 , at which point balloon  16 ′ can then be re-inflated fully to firmly seal the graft vessel  110  and prevent blood flow into the anastomosis site. By discontinuing the supply of light energy from the energy, the deformable material will become non-fluent and remain in its molded configuration. Both balloons  16 ′,  50  are then deflated and the catheter device  100  is withdrawn from the LITA graft vessel  110  to complete the anastomosis (see FIG. 13).  
         [0046]    [0046]FIG. 14 is a third alternative embodiment of a transillumination catheter generally indicated by reference numeral  200 . The transillumination catheter  200  is similar in most respects to the transillumination catheter  10  of FIGS.  1 - 2 , except that the distal end of the catheter  200  is substantially straight, and does not have a curved configuration as does the distal end of catheter  10 . A catheter guide  205  is shown in schematic form in FIG. 15. The guide  205  comprises a flexible, elongate tubular body  210  which is sized and dimensioned to permit catheter  200  to be longitudinally inserted within the tubular body  210 . Tubular body  210  may be manufactured from any suitable, relatively flexible biocompatible plastic such as polyethylene, polyurethane, silicone, and the like. The guide  205  facilitates placement of transillumination catheter  200  within an internal vessel, such as a LITA graft vessel. The catheter  200  may be formed with a guide wire lumen (not shown) as described in U.S. Pat. No. 5,169,395, which is incorporated herein by reference. The lumen may be used for insertion of a guidewire or insertion of a fluoroscopic dye to assist in guiding the catheter.  
         [0047]    In use of the above system, the guide  205  is first percutaneously inserted into a peripheral vessel, such as a brachial artery  48 , radial artery  51  or femoral artery  82 , and advanced over a guidewire  220  by conventional means to an internal vessel, such as LITA graft vessel. With the distal end of tubular body  210  positioned a short distance within the internal vessel, the guidewire  220  is pulled back and removed from tubular body  210 . Subsequently, transillumination catheter  200  can be longitudinally inserted into tubular body  210  and advanced transluminally through it such that the light transmitting diffusing end member  14 ′ is placed within the internal vessel and extends beyond the distal end of the tubular body  210 . Alternatively, tubular body  210  may be advanced into the internal vessel to a position at which transillumination of the vessel is required. Subsequently, the distal end of transillumination catheter  200  is advanced up to the distal end of tubular body  210 , and the tubular body  210  is then pulled back a short distance over the transillumination catheter  200  to expose the light transmitting distal end member  14 ′ of the catheter  200 . The transillumination catheter  200  is then used to illuminate the internal vessel as described above. The guide  205  is advantageous in that it can be used to effectively guide catheter  200  into an internal vessel, obviating the need to shape the distal end of catheter  200  or to provide a guidewire or other steering mechanism within catheter  200 .  
         [0048]    It should be understood that while the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications and equivalents may be used. Therefore, the above description should not be taken as limiting the scope of the invention which is defined by the following claims.