Abstract:
Two prostheses each have a tubular sidewall with a terminal portion extending to a connection end. A connector body has first and second terminal portions extending to first and second ends. The connector body terminal portions are respectively surrounded by the prostheses terminal portions. First and second straps respectively circumscribe the prostheses terminal portions to bias the prostheses into engagement with the connector body. The connector body has first and second strap engagement projections respectively captured by apertures in the straps.

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATION 
   This patent application is a divisional of U.S. patent application Ser. No. 10/405,805, entitled “Prosthetic Vascular Graft Connector,” filed on Apr. 2, 2003, now U.S. Pat. No. 6,896,688, which relates to and claims priority to U.S. provisional patent application No. 60/410,205, entitled “Prosthetic Vascular Graft Connector,” that was filed on Sep. 12, 2002. The subject matter of that provisional patent application is incorporated by reference in its entirety herein. 

   BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   This invention relates to a connector for interconnecting a first prosthetic vessel to a second prosthetic vessel, such as during reconstructive surgery. More particularly, the connector facilitates the rapid durable joining of a prosthetic graft to a bodily vessel or organ thereby reducing cross-clamp time to enhance recovery. 
   (2) Description of the Related Art 
   Vascular reconstructive surgery is utilized to replace portions of blood vessels damaged by aneurismal and occlusive diseases. One such type of replacement is an end-to-end anastomosis where a blood vessel is cut on either side of a diseased or damaged portion. Prosthetic devices are joined to the cut ends of the healthy portions of the blood vessel and a connector joins the prosthetic devices completing a vessel for the flow of blood that by-passes the damaged portion. Among the objectives of vascular reconstructive surgery is to minimize exsanguination at interfaces between the blood vessels and the prostheses and at interfaces between the prostheses, to minimize cross-clamp time (the time that the blood vessel is externally deprived of blood flow) and to minimize thrombogenicity (the formation of blood clots). The rate of the formation of blood clots tends to increase when flowing blood contacts different materials and when turbulence is introduced into the blood flow. 
   Exsanguination is minimized by a tight seal between the vessel and the prosthesis and between interconnected prostheses. Sutures and surgical staples are effective to achieve a tight seal between a prosthesis and a blood vessel and are widely used in vascular reconstructive surgery. Sutures and surgical staples are less efficient to form a tight seal between two prostheses. 
   As a replacement to sutures and surgical staples, it is known to interconnect a prosthesis to a blood vessel with an external clamp. Such clamps are disclosed in U.S. Pat. Nos. 3,357,432; 3,435,823 and 6,402,767, all three of which are incorporated by reference herein in their entireties. Generally, the prosthesis is inserted into the end of the vessel. The prosthesis has a locking structure on an external surface, such as detents or barbs. An external clamp or ring then closes about the vessel portion overlying the locking structure to thereby hold the vessel firmly in place. Due to the small scale of the vessels, manipulation and accurate placement of the locking structure has, to date, proven difficult. 
   Another vascular prosthesis connector is disclosed in FR2683141 by Thierry Richard and Eric Perouse entitled “Connection device for organ vessel prostheses.” 
   Accordingly, there remains a need for an effective mechanism to rapidly seal a first vascular prosthesis to a second vascular prosthesis that does not have the disadvantages recited above. 
   BRIEF SUMMARY OF THE INVENTION 
   In one aspect, the invention is directed to a vascular prosthesis and connector assembly. Two prostheses each have a tubular sidewall with a terminal portion extending to a connection end. A connector body has first and second terminal portions extending to first and second ends. The connector body terminal portions are respectively surrounded by the prostheses terminal portions. First and second straps respectively circumscribe the prostheses terminal portions to bias the prostheses into engagement with the connector body. The connector body has first and second strap engagement projections respectively captured by apertures in the straps. 
   In one embodiment of this aspect, the vascular prosthetic surface is everted about a connector. 
   In another embodiment of this aspect, a connector is pre-attached to either one or both ends of vascular prostheses. 
   Other aspects relate to methods of use and kits containing the subject connectors. 
   The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a view of a vascular prosthesis connector. 
       FIG. 2  is a longitudinal sectional view of the connector of FIG.  1 . 
       FIG. 3  is a view of a body of the connector of FIG.  1 . 
       FIG. 4  is a side view of the body of FIG.  3 . 
       FIG. 5  is an end view of the body of FIG.  3 . 
       FIG. 6  is a view of a strap of the connector of FIG.  1 . 
       FIG. 7  is a connector end view of the strap of FIG.  6 . 
       FIG. 8  is a cross sectional view of the strap of  FIG. 7  taken along line  8 — 8 . 
       FIG. 9  is a sectional view of the strap of  FIG. 7  taken along line  9 — 9 . 
       FIG. 10  is a longitudinal sectional view of a prosthesis. 
       FIG. 11  is a view of the prosthesis installed on the connector body. 
       FIG. 12  is a view of the installed prosthesis of  FIG. 11  circumscribed by a strap. 
       FIG. 13  is a view of a modular aorto-biiliac bypass. 
       FIG. 14  is an exploded view of the bypass of FIG.  13 . 
       FIG. 15  is a cross-sectional representation of a connector body in accordance with a second embodiment of the invention. 
       FIG. 16  is a cross-sectional representation of an assembled vascular prosthesis utilizing the connector body of FIG.  15 . 
       FIG. 17  is a perspective view of the connector body of FIG.  15 . 
     Like reference numbers and designations in the various drawings indicate like elements. 
   

   DETAILED DESCRIPTION 
     FIG. 1  shows a connector  20  for connecting a first end of a first vascular prosthesis  22  to a first end of a second vascular prosthesis  24  to by-pass a diseased or damaged portion of a blood vessel. Opposing second ends  26 ,  28  of the first  22  and second  24  vascular prostheses are joined to cut ends of healthy portions of the blood vessel on either side of the diseased or damaged portion. The opposing second ends may be joined to the blood vessels by conventional methods such as sutures or surgical staples. Further, use of the connector is not limited to human reconstructive surgery and may be used in veterinary applications as well. 
   An exemplary connector  20  is shown in cross-sectional representation in FIG.  2  and includes a connector body  30 , a first strap  32  and a second strap  33 . The connector body  30  is manufactured from any biocompatible material, including metals, plastics and carbon compounds, for example polyethylene or a pyrolytic carbon compound. Preferably, the connector body  30  is formed as a unitary molding from an injection molded plastic. The connector body  30  has a generally tubular structure configuration and extends for a length L along a central longitudinal axis  500  between first rim  36  and second rim  37  that define respective first and second ends of the connector body. The length “L” is dependent on the application. For an exemplary aortic anastomosis, “L” is from about 12 millimeters to about 14 millimeters. The connector body  30  has an inner (interior) surface  40  with a principal radius R I  and an outer (exterior) surface  42  with a principal radius R O . For the exemplary aortic anastomosis, R I  is from about 18 millimeters and R O  is from about 20 millimeters to about 24 millimeters. Typically, R O  is about 10% greater than R I . 
   A flange  44  extends radially outward from the connector body  30  along a central transverse plane  502  that divides the body into two halves. The exemplary flange has an outer radius R F  ( FIG. 5 ) that is from about 1.5 millimeter a thickness T of from about 0.5 millimeter. As shown in  FIG. 2 , central transverse plane  502  bisects the flange  44  and separates first connector body portion  46  from second connector body portion  48  with each tube portion having a respective length, L H1  or L H2 . L H1  is typically, but not necessarily equal to L H2 . 
   Along a peripheral surface of the first  46  and second  48  connector body portions, offset from the associated rim  36  and  37 , a first circumferential array of detents  50  and a second circumferential array of detents  51  extend radially exterior from the outer surface  42  to an apex  52  at a radius R T  (see FIGS.  4  and  5 ). Described in further detail below, the detents  50 ,  51  extend upward from the exterior surface  42  (see  FIG. 2 ) for a distance effective to engage and retain the prostheses  22 ,  24 . Typically, the detents extend upward from the exterior surface  42  for a distance of about 1 millimeter when formed from plastic. Somewhat smaller detents are effective when formed from metal. 
   A pair of opposed shafts  60  and  61  shown in  FIGS. 2 and 3  extend from the flange  44  along an axis  504  shown parallel to the axis  500 . Exemplary shafts are of circular section of diameter D S  and length L S  (as shown in FIG.  4 ). Each shaft is spaced radially outboard from its associated portion  46 ,  48  of the connector body  30 . Described in further detail below, the shafts  60 ,  61  may serve as a handle for maneuvering the connector body and may serve to position the associated straps  32  and  33 . The shafts enable the prosthesis to be easily and accurately manipulated even during laparoscopic surgery and other procedures with limited access for the surgeon. The shafts may be formed to be removable from the connector body, integral with the connector body, or unitary with the connector body, such as when formed as part of the same molded piece. 
     FIG. 6  shows an exemplary strap  32 . Depending on positioning circumstances, such a strap or a mirror image thereof could be utilized as either of the straps  32  and  33 . The strap extends from a proximal end  70  to a distal end  72  and has generally inner (interior) and outer (exterior) surfaces  74  and  76 . The strap inner surface has a channel  78  dimensioned to accommodate the associated detents, (e.g.,  50  or  51  of  FIG. 2 ) and portions of the associated prosthesis (e.g.,  22  of  FIG. 2 ) pushed into the channel by such detents. Advantageously, at an inboard side of the strap, there is a generally radial surface  80  joining the surfaces  76  and  78 . At an outboard side of the strap, the strap largely tapers, with the outer surface  76  tapering inward to meet the inward surface  74 . A blind longitudinal hole or compartment  90  extends from the surface  80  and for receiving the associated shaft  60 ,  61 . 
   A channel  100  is provided in the outer surface  76  slightly recessed from the compartment  90 . A complementary projection  102  is provided extending radially inward from the inner surface  74  near the distal end  72 . In an engaged condition (described below), the channel  100  receives the projection  102  to lock the strap in a ring-like state. When locked, the strap prevents relative movement between the prostheses and the connector body. The locking of the strap is reversible. The strap may be disengaged by separating the projection from the channel. When the strap is unlocked, the connector may be further manipulated or replaced. Alternatively, other locking methods may be employed. 
     FIG. 7  is an end view of a strap while  FIGS. 8 and 9  illustrated selected portions of the strap in cross-sectional representation. 
     FIG. 10  shows an exemplary vascular prosthesis  22  having a generally tubular body  120  extending from a first end  122  to an opposing second end  26 . The exemplary body is formed of woven or knitted polyester or other suitable fabric. One preferred polyester is poly (ethylene terephthalate), such as Dacron (manufactured by DuPont of Wilmington, De.). A major portion of the tubular body  120  has an internal radius R B . The illustrated embodiment includes an enlarged terminal portion  126  adjacent the first end  122 . The exemplary terminal portion extends over length L T  and, over a major portion thereof, has an internal radius R E . The terminal portion is provided for coupling to the connector  20  with an associated portion of the connector body  30  being received within the enlarged terminal portion  126 . The radius R E  may be chosen relative to the radius R O  to provide insertion of the connector with appropriate snugness. The radius R B  may be chosen relative to the radius R I  so that, when the prosthesis is installed and carrying blood, the connector does not provide an undue flow restriction (e.g., R I  is chosen to be equal to R B ). 
   In one application of the connector of the invention, a vascular reconstructive surgical procedure entails coupling the second ends  26  of two prostheses to healthy portions of the patient&#39;s cardiovascular system on either side of a diseased or damaged portion and securing the connector to both first end  122  enlarged terminal portions  126  to couple the two prostheses. The connector may be pre-secured to one of the prostheses before the surgeon installs such prosthesis. The surgeon may so pre-secure (pre-install) or the packaged prosthesis may come with the connector pre-installed. To install each half of the connector to its associated prosthesis, the surgeon inserts a connector body portion ( 46 ,  48  in  FIG. 2 ) into the enlarged terminal portion  126 . This may be done by holding the connector body with a surgical instrument. For example, with reference to  FIG. 11 , the connector  20  may be held by one or both of the shafts  60 ,  61 . The prosthesis enlarged terminal portion is then drawn over the tube portion  46  or  48 , advantageously with a slight degree of stretch so as to firmly engage the detents  50 . Advantageously the detents are pointed and point outward from the connector body to pierce the terminal portion and resist its retraction. With reference to  FIG. 12 , when the terminal portion is installed, the surgeon then installs the associated strap  32 . This is done by manipulating the strap  32  with the associated shaft  60  and wrapping the strap around the terminal portion  126 , finally inserting the projection  102  into the channel  100  (as illustrated in  FIG. 6 ) to lock the strap  32  in its installed condition. 
   The connector body is advantageously formed of an appropriate plastic having sufficient rigidity to withstand the pressure envelope of the patient&#39;s viscera and is further biologically inert within the human body. Such plastics are dimensioned to a size effective to withstand arterial pressures of up to 300 millimeters. Preferred plastics include polyurethane and polyethylene. Other biocompatible materials such as metals and carbon compounds are also suitable. The connector may be dimensioned for particular applications. Size may be conveniently designated by an appropriate diameter or associated radius such as the interior diameter or its associated radius R I . In an exemplary 20 mm embodiment, the radius R I  is 10 mm and the radius R O  is 11 mm. The 20 mm embodiment is near the large end of a size spectrum. Near the small end of that spectrum, an exemplary 6 mm embodiment has a radius R I  of 3 mm and a radius R O  of 4 mm. The scaling of connector body wall thickness relative to size will be largely influenced by structural integrity considerations. Accordingly, the wall thickness may increase less than proportionately. 
   The detent height is R T -R O  and is influenced principally by the material and thickness of the prostheses. Exemplary woven polyester prostheses have a wall thickness of 0.3-0.4 mm for such material, exemplary detent height is about twice the prosthesis wall thickness (e.g. about 1-3 times) or approximately 1 mm. The length L H  will be influenced by structural integrity considerations and by considerations relating to the ease of assembling the prosthesis and strap to the body weighed against compactness considerations. An L H  of about 2.5 mm may be a practical minimum. For the relatively small exemplary 6 mm size, an L H  of about 3 mm may be appropriate. For the relatively large exemplary 20 mm size, an L H  of about 5 mm may be appropriate. An exemplary flange thickness T is 1 mm. The detents advantageously fall along the outboard half of the length L H . The handle shaft length L S  is advantageously about half L H  to avoid clearance problems relative to the detents. 
   An exemplary strap is molded of an appropriate plastic that is biologically inert within the body. Suitable plastics include polyethylene or polyurethane with a thickness of about 3 millimeters. An exemplary principal thickness T S  is about 2 mm and an exemplary width W S  is equal to L H . Advantageous values of T S  may be relatively insensitive to size. The flange radius R F  is advantageously the same as the outer radius of the installed straps. 
     FIG. 13  shows a flow-splitting prosthesis (“flow splitter”)  200  installed in an aorto-biiliac bypass establishing communications between a patient&#39;s aorta  600  and iliac arteries  602  and  604 . The flow splitter  200  is generally Y-shaped, having a leg or trunk  202  and a pair of first and second arms or branches  204  and  206 . The flow splitter  200  is coupled to the arteries by respective connection prostheses  202 ,  204 , and  206 . The flow splitter  200  is coupled to the prostheses  202 ,  204 , and  206  via respective couplers  208 ,  210 , and  212 . Except as otherwise described, these couplers may be otherwise similar to the connector (illustrated in either  FIG. 2  or  FIG. 15  as described below) and have similar interaction with the associated prostheses. 
   Prior to surgery, the sizes of the prostheses  202 ,  204 , and  206  will be selected based upon medical imaging. Most key is the cross-sectional area characterized by a diameter or radius. Length may also be relevant and may be used to either select a particular prosthesis or cut a prosthesis to a particular length. By way of example, the prostheses  202 ,  204 , and  206  may have nominal diameters of eighteen, eight and ten mm, respectively in one common size combination. 
   With reference to  FIG. 14 , in an exemplary surgical procedure, the bodies of the couplers  208 ,  210 , and  212  are preinstalled on associated ends of the prostheses  202 ,  204 , and  206 . They may be so installed with respective straps  214 ,  216 , and  218 . Alternatively, they may be secured by other means for example when only the other half of each connector body is adapted for receipt of such straps. 
   The components illustrated in  FIG. 14  may be provided in kit form. For example. Prostheses  202 ,  204  and  206  are supplied from a medical supply house with connectors  208 ,  210  and  212  pre-attached. The kit would further include a required prostheses  200  and a number of locking straps  222 ,  224  and  226 . It is preferred, but not required, that the connectors  208 ,  210  and  212  would be of similar configuration such that locking straps  222 ,  224  and  226  are interchangeable. 
   The surgeon secures the connection prostheses  202 ,  204 , and  206  to their associated arteries. In the illustrated example, the connection prosthesis  202  is surgically stapled to the aorta  600  in an end-to-end anastomosis. Suturing is an alternative. The connection prosthesis  204  is also secured to its iliac artery  602  via an end-to-end anastomosis such as via stapling or suturing. The connection prosthesis  206  is connected to its iliac artery  604  via an end-to-side anastomosis such as via suturing or stapling. 
   After installation of the connection prostheses  202 ,  204 , and  206 , the surgeon may install flow splitter  200 . If the coupler bodies are preinstalled at the factory to their associated connection prostheses  202 ,  204 , and  206 , rings  222 ,  224 , and  226  may be prepackaged with such connection prostheses. Alternatively, such rings may be prepackaged with the flow splitter  200  or otherwise provided. With the connection prostheses  202 ,  204 , and  206  installed, the surgeon may finally size the flow splitter  200  by removing distal lengths of one or more of the trunk  192 , first branch  194 , and second branch  196  to define final ends  230 ,  232 , and  234 , respectively. Terminal portions adjacent to these ends are in turn placed by the surgeon over associated end portions of the bodies of connectors  208 ,  210 , and  212  and secured with straps  222 ,  224 , and  226 . Blood flow is then reestablished and the surgery site closed. 
   In accordance with another embodiment of the invention, an alternative connector  20 ′ is illustrated in cross-sectional representation in  FIG. 15. A  first prosthesis  22  extends through an interior bore  302  of connector body  300 . An end portion  303  of the first prosthesis  22  is everted  304  and folded back over a first rim  306  of the connector body  300  and engaged along an exterior surface of the connector body, such as by detents  308 . As illustrated in  FIG. 16 , a second prosthesis  24  intended to be joined to the first prosthesis  22  has an enlarged terminal portion  309  extended over the end portion  303  of the first prosthesis and engaged on detents  308 . When properly positioned, strap  310  is circumscribed about the connector body  300  to firmly retain the connector in place. Throughout the assembly, handle  312  is used to manipulate the connector body. 
   The embodiment of  FIG. 15  is further illustrated in perspective representation in  FIG. 17  where first prosthesis  22  has been extended through the interior bore of connector body  300  and an end portion  303  everted and engaged on detents  308 . Handle  312  provides ease of manipulation. 
   In the embodiment illustrated in  FIGS. 15-17 , the surface contacting the blood remains that of the prostheses, rather than a transition to the interior bore of the connector. Avoiding the changing of surface chemistry reduces the risk of thrombosis inherent when the chemistry of the surfaces contacted by the blood changes. Thrombogenicity is further reduced by a reduced turbulence imparted into the blood flow. 
   One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the connectors may be tailored for a variety of general or specific applications. Accordingly, other embodiments are within the scope of the following claims.