Patent Publication Number: US-6659327-B2

Title: Surgical anastomosis apparatus and method thereof

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of patent application Ser. No. 09/756,426, filed Jan. 8, 2001, now U.S. Pat. No. 6,450,390, which is a continuation of patent application Ser. No. 09/488,140, filed Jan. 20, 2000, now issued as U.S. Pat. No. 6,176,413, which is a division of patent application Ser. No. 09/267,247, filed Mar. 12, 1999, now issued as U.S. Pat. No. 6,253,984, which is a divisional of patent application Ser. No. 08/979,831, filed Nov. 20, 1997, now issued as U.S. Pat. No. 5,881,843, which is a continuation of application Ser. No. 08/759,110, filed Dec. 2, 1996, now abandoned, which is a continuation-in-part of application Ser. No. 08/550,285, filed Oct. 31, 1995, now issued as U.S. Pat. No. 5,709,335, which is a continuation of application Ser. No. 08/261,167, filed Jun. 17, 1994, now abandoned, the complete disclosures of which are hereby incorporated herein by reference for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to surgical stapling appliances and more particularly to an improved apparatus and method for the anastomotic surgical stapling of luminal organs, such as vascular lumens. 
     BACKGROUND OF THE INVENTION 
     Various instruments are known in the prior art for end-to-end and end-to-side anastomotic surgical stapling together of parts of the alimentary canal (i.e., esophagus, stomach, colon, etc.). These instruments employ staple cartridges, generally in the shape of a hollow cylinder, of different sizes to accommodate tubular organs of varying diameters. End-to-end and end-to-side anastomoses are achieved by means of at least one ring of surgical staples. 
     The traditional technique for surgical stapling anastomosis is to position the stapling cartridge within the tubular organ to be stapled. The cut end of the tubular organ is inverted (i.e. folded inwardly) over the annular end of the staple cartridge creating an inverting anastomosis upon stapling. An essential requirement of the inverting anastomotic technique is the incorporation of knives within the staple cartridge to trim excess tissue from the anastomotic connection. 
     The prior art anastomotic stapling instruments form generally circular anastomotic connections, and have been largely limited to alimentary organs. With respect to end-to-side vascular anastomosis, circular connections, rather than an elliptical connections, are sometimes disadvantageous as they are less physiologic or natural. This unnatural connection may create turbulence in the blood flow as it courses through the anastomosis, damaging the intima (i.e. inner wall) of the blood vessel and predisposing it to forming blood clots. 
     In the present state of the art, end-to-end and end-to-side anastomosis between blood vessels have typically been accomplished by hand-sewn suturing techniques. These techniques are time consuming, not as reliable as stapling, and subject to greater human error than stapling. Current stapling instruments used for alimentary canal are not suitable, however, for vascular anastomosis due to their large sizes and inability to provide non-circular and low turbulence anastomoses. A typical prior art instrument has a circumference of approximately 8 cm (3 in), far too thick to accommodate coronary arteries and veins, which have circumferences ranging from 0.50 to 1.0 cm and from 1.5 to 2.5 cm, respectively. 
     An additional drawback of prior stapling instruments is the inability to provide an everted (i.e. folded outwardly) anastomosis. An inverted vascular anastomosis would expose the cut ends of the blood vessels to the vessel lumen and could lead to the formation of blood clots. For this reason, hand-sewn everted anastomoses for vascular connections are preferable, despite time and reliability drawbacks. 
     Accordingly, it is a general object of the present invention to provide an improved instrument and method for vascular anastomosis. 
     It is also an object of the present invention to provide a surgical anastomosis apparatus small enough to accommodate vascular lumens. 
     Another object of the present invention is to provide a surgical anastomosis apparatus for everted anastomosis. 
     Another object of the present invention is to provide a method for surgical stapling that does not require the removal of excess tissue from the anastomotical connection. 
     Still another object of the present invention is to provide an instrument and method for vascular anastomosis that is less time-consuming and more reliable than the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention provides a novel instrument and method for vascular anastomoses which overcomes the drawbacks of prior art designs and achieves the aforesaid advantages. 
     Very generally, the surgical stapling instrument of the present invention is for stapling a tubular tissue structure having at least one distal end to a luminal structure, such as a vascular lumen or another tubular tissue structure. The instrument comprises a rod having a circumference sufficient to pass within the tubular tissue structure, an anvil mounted on the rod, and a generally tubular staple cartridge for containing a plurality of staples. The anvil has an array of staple deforming means thereon and is of a size sufficient to pass through a surgically formed opening in and to be accommodated within the luminal structure. The inner passage of the staple cartridge is sufficient to axially accommodate the tubular tissue structure between the rod and the inner surface of the staple cartridge, and sufficient to allow the staple cartridge to be moved axially along the rod. The staple delivery end of the staple cartridge is positioned toward the staple deforming means of the anvil and has an outer dimension small enough so that the tubular tissue structure can be everted thereover. A clamping mechanism secures the everted portion of the tubular tissue structure and the luminal structure adjacent to the surgically formed opening between the staple cartridge and the anvil. A plurality of staples may then be ejected to pass through the everted portion of the tubular tissue structure and the luminal structure to engage the staple deforming means to deform the staples and create a bond between the tubular tissue structure and the luminal structure. 
     In another aspect of the present invention, an end-to-side surgical anastomosis apparatus is provided for stapling an end of a tubular tissue structure to a side of a luminal structure. The anastomosis apparatus includes an elongated housing defining a central bore extending longitudinally therethrough and terminating at a bore opening at a distal end of the housing. The central bore includes a transverse cross-sectional dimension sufficiently sized and configured for receipt of the tissue structure therein in a manner positioning the end of the tissue structure through the bore opening. The elongated housing further includes an eversion support surface extending circumferentially about the bore opening adjacent the distal end. This surface is configured to retain and support an everted end of the received tissue structure which extends through the bore opening to face an intimal surface of the tissue structure in an outward direction. The anastomosis apparatus further includes an anvil having a fastener engaging surface, and a compression device having a shoulder portion formed for selectively compressing the everted end of the tissue structure and a surface of the luminal structure together against the fastener engaging surface. The compression device is further formed to deform the fasteners into contact with the everted end of the tubular tissue structure and the luminal structure to create an anastomotic bond between the tubular tissue structure and the luminal structure. 
     At least one driver pin is preferably provided moveable relative to the compression device for ejecting the plurality of fasteners through the everted end of the tubular tissue structure and the luminal structure to engage the fastener engaging surface. This engagement deforms the fastener and creates a bond between the tubular tissue structure and the luminal structure. 
     In still another aspect of the present invention, a method of end-to-side surgical anastomosis is provided between a tubular tissue structure, having at least one end, and a luminal structure, such as a vascular lumen or another tubular tissue structure. The method includes the steps of A) inserting the tubular tissue structure in a central bore of an anastomosis apparatus, and B) everting an end of the tubular tissue structure over and against an eversion support surface of the anastomosis device and at a distal end of the central bore to an everted condition positioning an intimal surface of the everted end in a direction facing outwardly. The next steps of the present invention include C) positioning the everted end of the tubular tissue structure and a surface of the luminal structure between an anvil and an opposed shoulder of a compression device of the anastomosis apparatus, and D) contacting the intimal surface of the everted end with a surface of the luminal structure adjacent a surgically formed opening therein. Finally, the last step of the method of end-to-side surgical anastomosis of the present invention includes E) applying a plurality of fasteners to the everted end of the tubular tissue structure and the surface of the luminal structure to contact the anvil and deform the fasteners to form an anastomotic bond therebetween. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The procedure and system of the present invention have other objects and features of advantage which will be readily apparent form the following description of the Best Mode of Carrying Out the Invention and the appended claims, when taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a fragmentary side elevation view, in cross section, of one embodiment of the anastomosis device constructed in accordance with the present invention and illustrating an end of the tubular tissue structure everted over the device end. 
     FIG. 2 is a front elevation view, in cross-section, of the anastomosis device taken substantially along the plane of the line  3 — 3  in FIG. 1 
     FIG. 3 is a rear elevation view, in cross-section, of the anastomosis device taken substantially along the plane of the line  2 — 2  in FIG. 1 
     FIG. 4 is a side elevation view, in cross-section, of the anvil of the anastomosis device taken substantially along the plane of the line  4 — 4  in FIG. 3 
     FIG. 5 is a front elevation view, in cross-section, of an alternative embodiment of FIG. 3 illustrating a tear drop-shaped configuration. 
     FIG. 6 is a rear elevation view, in cross-section, of the anvil of the alternative embodiment of FIG. 5 taken substantially along the plane of the line  2 — 2  in FIG. 1 
     FIG. 7 is an exploded top perspective view, partially cut-away, of the anastomosis device of FIG.  1 . 
     FIG. 8 is an enlarged, exploded, top perspective view, partially cut-away, of a staple cartridge assembly of the anastomosis device of FIG.  1 . 
     FIG. 9 is an enlarged, side elevation view, in cross-section, of the anvil and staple cartridge assembly of the anastomosis device of FIG. 1 illustrating the deformation of a staple. 
     FIGS. 10-12 is a sequence of top perspective views illustrating the loading of a tubular tissue structure in the anastomosis device of FIG. 1 
     FIG. 13 is an enlarged, side elevation view, in partial cross-section, showing the positioning of the anvil of the anastomosis device through a luminal structure. 
     FIG. 14 is a reduced top perspective view of the anastomosis device of FIG. 1 mounted to the luminal structure. 
     FIG. 15 is a reduced top perspective view of the tubular tissue structure anastomotized to the luminal structure using the anastomosis device of FIG.  1 . 
     FIG. 16 is a front elevation view of a grafted tubular tissue structure anastomotized to a coronary artery of the heart through the anastomosis device of FIG.  1 . 
     FIG. 17 is an exploded top perspective view of an alternative embodiment of the anastomosis device of the present invention. 
     FIG. 18 is a fragmentary, enlarged top perspective view of a staple cartridge assembly of the alternative embodiment anastomosis device of FIG.  17 . 
     FIG. 19 is an end view of the staple cartridge assembly of FIG.  18 . 
     FIGS. 20-22,  24 ,  25 ,  27  and  28  is sequence of top perspective views illustrating the application of the alternative embodiment anastomosis device of FIG. 17 for proximal anastomosis of the grafted tubular tissue structure to the ascending aorta. 
     FIGS. 23 and 26 is a sequence of fragmentary, top perspective views illustrating the loading of a tubular tissue structure in the alternative embodiment anastomosis device of FIG. 17 
     FIG. 29 is a fragmentary, top perspective view of an alternative embodiment anastomosis device constructed in accordance with the present invention. 
     FIG. 30 is an enlarged, fragmentary side elevation view, in cross-section, of the anastomosis device of FIG. 29 illustrating a distal end of the tubular tissue structure everted over a distal end of the eversion mandrel. 
     FIG. 31 is a top plan view of the anastomosis device of FIG. 29 taken substantially along the plane of the line  31 — 31  in FIG.  30 . 
     FIG. 32 is a fragmentary side elevation view, in cross-section, of an alternative embodiment bell-shaped distal end of the eversion mandrel of FIG. 31 having the tubular tissue structure everted over a distal end of the bell-shaped eversion mandrel. 
     FIG. 33 is a fragmentary, top perspective view of the eversion mandrel of anastomosis device of FIG. 29 in an opened condition. 
     FIG. 34 is a fragmentary, enlarged top plan view of a hinge assembly of the anastomosis device of FIG.  29 . 
     FIG. 35 is a fragmentary, top perspective view of the anastomosis device of FIG.  29  and illustrating the tubular tissue structure everted over the distal end of the eversion mandrel. 
     FIG. 36 is an enlarged, fragmentary side elevation view, in cross-section, of the anastomosis device of FIG. 29 illustrating a compression device in a compressed condition. 
     FIG. 37 is an enlarged, fragmentary, top perspective view, partially cut-away, of the eversion mandrel of the anastomosis device of FIG. 29 positioned in a surgically formed opening in a luminal structure. 
     FIG. 38 is an enlarged, fragmentary side elevation view, in cross-section, of the tubular tissue structure grafted to the luminal structure employing the anastomosis device of FIG.  29 . 
     FIG. 39 is an enlarged, fragmentary top perspective view of a tubular tissue structure grafted to the luminal structure employing the anastomosis device of FIG.  29 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the invention. The present invention provides methods and devices for performing surgical interventions within the heart or a great vessel such as the aorta, superior vena cava, inferior vena cava, pulmonary artery, pulmonary vein, coronary arteries, and coronary veins, among other vessels. While the specific embodiments of the invention described herein will refer to a closed-chest surgical procedure and system for the treatment of medically refractory atrial fibrillation, it should be understood that the invention will be useful in performing a great variety of surgical procedures requiring the ablation of tissue structure, including surgical treatment of Wolfe-Parkinson-White (WPW) Syndrome, ventricular fibrillation, congestive heart failure and other procedures in which interventional devices are introduced into the interior of the heart, coronary arteries, or great vessels. Advantageously, the present invention facilitates the performance of such procedures through percutaneous penetrations within intercostal spaces of the rib cage, eliminating the need for a median sternotomy or other form of gross thoracotomy. However, as will be apparent although not preferred, the system and procedure of the present invention could be performed in an open-chest surgical procedure as well. 
     Referring to FIGS. 1-7, there is shown a structural embodiment of the present invention which is best suited for anastomotic stapling of a tubular vessel having two distal or untethered ends. As will be evidenced by the detailed description below, this embodiment, i.e., distal stapler, is ideal for use during cardiopulmonary bypass surgery for making the primary anastomotic connection of a bypass vein to a coronary artery or to the aorta. 
     Referring now to FIG. 1, a portion  10  of the wholly configured distal stapler of the present invention, as shown in FIG. 7, comprises an elongated central rod  12  with anvil  14  mounted at its distal end  16 . Anvil  14  is in the form of a circular, elliptical or tear drop-shaped disk and is mounted, by suitable means such as welding, to the end of central rod  12  transversely thereof and at the center of the anvil. The edges of anvil  14  are beveled or otherwise generally rounded to enable anvil  14  to slip easily through incisions in vascular walls—much like a button through a button hole. 
     The central rod  12  has a circumference sufficient to permit the rod to axially extend through a tubular vessel, indicated in phantom at  20 , to be stapled. Central rod  12  also axially extends within tubular housing  22 , driver pins  24  and staple cartridge  26 , together forming a contiguous shaft  28  having an inner circumference sufficient to accommodate tubular vessel  20  sandwiched between them and central rod  12 . Staple cartridge  26  has an outer circumference sufficient to accommodate everted end  34  of tubular vessel  20 . Lip  36  of cartridge  26  is tapered to facilitate eversion of tubular vessel  20 . Anvil  14  has circumference of a size equivalent to the outer circumference of staple cartridge  16 . 
     Circumferences of vascular vessels range from 0.50 to 1.0 cm for coronary arteries and from 1.5 to 2.5 cm for veins. Accordingly, all circumferences, discussed above, of stapler  10  are of a size to optimally coaxially accommodate the vein to be stapled. 
     The end of central rod  12  opposite anvil  14  is centrally mounted, preferably welded, on a cylindrical base  40  which extends coaxially within tubular housing  22  (as shown in FIG. 7 by reference number  106 ) and has a circumference sufficient to be slidable within tubular housing  22 . The accommodated tubular vessel  20  extends along central rod  12  to cylindrical base  40 . Provided on the surface of central rod  12  proximal to base  40  is circumferential groove  44  for facilitating the securing of tubular vessel  20  to rod  12  by means of string  46 . Similarly, circumferential groove  48  and string  50  are provided to secure everted end  34  of vessel  20  to staple cartridge  26 . An alternative embodiment of staple cartridge  26  for securing an everted vein comprises tiny hooks around the circumference at end  36  of the cartridge. Other suitable means for accomplishing the securing function may be used as well. 
     Referring now to FIG. 2, there is shown a cross-sectional view of stapler  10  of the present invention in the direction of arrows  2 — 2  of FIG.  1 . Here, the staple delivery end  60  of a circular staple cartridge is illustrated encasing a circular array of staple delivery means or staple shafts  62 . The present invention is not limited to a single staple shaft array, however. It is commonly known in the art to employ a plurality of concentric arrays or rows of staple shafts for anastomotic procedures. Extending from staple shaft array  62 , is an array of narrow channels  68 , each narrow channel corresponding to each staple shaft. Channel array  68  is used solely for manufacturing purposes and is not a necessary element of the invention. Central rod  64  and its base  66  are axially and centrally located within the cylindrical staple cartridge  60 . 
     FIG. 3 shows the underside view of anvil  70  in the direction of arrows  3 — 3  of FIG.  1 . The anvil  70  has an array  74  of means for deforming staples. Central rod attachment  72  is centrally located on anvil  70  which provides an array of staple deforming means  74 , comprised here of an array of recess pairs, for bending staples projected from corresponding array of staple shafts  62  of the staple cartridge of FIG.  2 . 
     Depicted in FIG. 4 is a cross-sectional view of anvil  70  in the direction of arrows  4 — 4  of FIG.  3 . Each recess pair  76  is curved to bend staple legs radially inward. The projected staples can be made to bend radially inward or radially outward depending on the spacing  78  between the recess of each paired recess  76 . Alternatively, each recess can be positioned orthogonal to its present position to bend the staple legs at right angles to their axis of projection. 
     Although the present invention is primarily described and depicted as forming staple bonds that are circular and as having component circumferences that are circular, other embodiments are realized for forming staple bonds having elliptical, tear drop or other generally oval circumferences. Accordingly, the anvil and associated staple recess array, and the cartridge housing and associated staple shaft array of these alternative stapler embodiments have circumferences in the shape of the desired staple bond. For example, FIGS. 5 and 6 illustrate an anvil and staple cartridge, respectively, having tear-drop shaped circumferences. 
     FIG. 5 shows a cross-sectional view of a tear-drop shaped staple cartridge. The staple delivery end  80  of the staple cartridge is illustrated encasing a tear drop array of staple delivery means or staple shafts  82 . Extending from staple shaft array  82 , is an array of narrow channels  84 , each narrow channel corresponding to each staple shaft. Channel array  84  is used solely for manufacturing purposes and is not a necessary element of the invention. Central rod  86  and its base  88  are coaxially and centrally located within the cylindrical portion of dear drop staple cartridge  80 . 
     FIG. 6 shows the underside view of a tear drop shaped anvil  90 . Central rod attachment  92  is centrally located on the circular portion of anvil  90  which provides an array of staple deforming means comprised of recess pairs  94  for bending staples projected from corresponding array of staple shafts  82  of the staple cartridge of FIG.  5 . 
     Referring now to FIG. 7, there is shown stapler  100  of the same embodiment depicted in FIGS. 1-4. A tubular housing  102  coaxially contains central rod  104  and rod base  106 , the end of central rod  104  opposite that of anvil  114  being suitably mounted, such as by welding, to rod base  106  (connection not shown). Threadedly mounted to and extending perpendicular from rod base  106  is a short stem  108 , positioned at approximately half the length of base  106 . The top of stem  108  has cylindrical knob  110  transversely mounted. Stem  108  is moveable within narrow channel  112 , cut within housing  102  and running parallel to the axis traveled by central rod  104  and rod base  106 . Channel  112  limits the rotational movement of stem  108  and thereby maintains a proper radial orientation between anvil  114  and staple cartridge  116  during reciprocation. 
     Weldedly mounted to and protruding perpendicularly from cylindrical face  118  of housing  102  and paralleling rod  104  is cylindrical array of staple driver pins  120 , all drivers pins being identical and each having the form of a solid parallelogram. Staple cartridge  116  encases, from end to end, cylindrical array of hollow staple shafts  122  which holds a plurality of preloaded staples (not pictured). All shafts  122  are identical and each has height and width dimensions such that a corresponding staple driver pin  120  is slidable therein. 
     In order to have an optimally functioning stapler, it is necessary to maintain a clean and clear passageway for central rod  104 , base  106  and staple shafts  122 . Accordingly, one embodiment of the present invention comprises a disposable cartridge which is disposed of and replaced after one anastomotic stapling. Another embodiment provides a slidable sleeve around the driver pin array to prevent blood and tissue from getting caught therein. 
     For anastomosis to be successful, it is imperative not to injure the living tissue being stapled by overcompressing it between anvil  114  and staple cartridge  116  or by a staple bond that is exceedingly tight. Accordingly, overcompression of the tissue is prevented in the present invention by limiting the length of driver pins  120 . Other embodiments are known in the prior art for accomplishing this objective. For example. U.S. Pat. No. 4,573,468 employs mutually coacting stops located on the inner surface of a tubular housing and on the surface of a coaxial rod to provide variable degrees of engagement between tissues to be stapled so as to ensure against overcompression of the tissue. A spring-loaded engagement between the rod and tubular housing is also applicable for the present invention. Other means suitable for this purpose will be apparent to those having ordinary skill in the art. 
     Finally, FIG. 7 illustrates threaded end  124  of rod base  106  which extends beyond the length of housing  102  to threadedly engage with cylindrical nut  126  which has internally threaded throughbore  128  extending the full length of cylindrical nut  126  to allow end  124  to exit therethrough. 
     FIGS. 8 and 9 illustrate the mechanical interaction between the staple driver, staple cartridge and anvil upon engagement. FIG. 8 illustrates staple driver array  200  mounted on face  202  of tubular housing  204  slidably engaged within staple shaft array  206  of staple cartridge  208 . Staple array  210  is projected from staple cartridge  208  and through the tissues to be stapled (not shown). FIG. 9 shows a close-up of a staple being driven by driver pin  252  and projecting through cartridge  254  through tissues  256  and  258 . The legs  260  and  262  of staple  250  then engage with and bend along the curved recesses  264  and  266 , respectively, of anvil  268  to form a bond between tissues  256  and  258 . 
     Referring now to FIGS. 10-16, with like numbers referring to like elements, there is illustrated the steps of the anastomotic procedure using the structural embodiment described above. Now referring to FIG. 10 specifically, the anvil-headed end of rod base  302  is inserted into transected vein  304  having a length in the range of 10-18 cm (4-7 inches). End  308  (the end to be stapled) of vein  304  is positioned proximate to anvil  306 . Opposing end  310  of vein  304  is tied with string  312  to central rod  314  at a circumferential depression (not shown) proximate to base  302 . 
     FIG. 11 shows the step of inserting central rod  314  with attached vein  304  into staple cartridge  318  and tubular housing  316  such that staple cartridge  318  is proximate to anvil  306 . FIG. 12 illustrates the next several steps of the method of the present invention which can be performed in any order. The end of vein  304  is everted over staple cartridge  318  and tied with string  320  securing it to staple cartridge  318  (covered by vein  304 ). Threaded stem  322  of cylindrical knob  324  is threadedly engaged with a threaded bore (not shown) base  302 , the bore being aligned with narrow channel  326 . Cylindrical nut  328  is threadedly engaged with the threaded end  300 . As indicated in FIG. 13, anvil  306  is positioned within lumen  330  of vascular artery  332  via incision  334 . A cross-section of a portion of vein  304  is shown everted over the staple delivery end of staple cartridge  318 . 
     In FIG. 14, central rod  314  (not visible) and rod base  302  (not visible) are optimally coaxially positioned within tubular housing  316  by means of sliding knob  324  along channel  326  toward vascular artery  332 . Nut  328  is rotated in a clockwise direction to engage it with tubular housing  316  causing rod base  302  to become rigidly interconnected with nut  328 . As the clockwise turning continues, rod base  302  is drawn through the bore in nut  328 , bringing the staple cartridge  336  and anvil  306  within artery  332  together. An embodiment employing mutually coacting stops (not shown) would, at this point, be at the first coacting position or the “loaded” position. The clockwise motion is continued so that everted vein  304  engages with the wall of artery  332  and until the staple drivers (not visible) are actuated, driving the staples (not visible) through the tissues to create a bond  338  (FIG.  15 ). If mutually coacting stops are employed, the configuration would be in the “firing” position. 
     Finally, FIG. 16 illustrates heart  350  having aorta  352 , pulmonary artery  354 , right atrium  356 , right ventricle  358 , left ventricle  360 , left atrial appendage  362 , right coronary artery  364 , left anterior descending artery  368 , and diagonal artery  370 . Here, vein  304  has been anastomotically stapled to left anterior descending artery  368 . 
     To complete the anastomotic procedure of the bypass vein  304 , the unstapled end of the anastomotized vein  304  must now be connected to aorta  352 . However, another structural embodiment of the present invention, referred to as the “proximal” stapler, is needed since the embodiment described above, i.e., the “distal” stapler, requires the vein to have two distal or untethered ends. Accordingly, FIGS. 17-28 describe a structure and method thereof for a second embodiment of the present invention which is suited for the anastomotic stapling of a tubular vessel having only one distal end, the other end having already been anastomotically stapled. 
     Referring now to FIGS. 17-19, with like numbers referencing like elements, there is shown anastomotic stapler  400  having handle  402  with elongated vessel rod  404  and elongated driver rod  406  mounted perpendicularly to handle face  408  and parallel to each other, both being of approximately the same length. Vessel rod  404  has a centrally mounted generally circular anvil  410 . Vessel rod  404  has a circumference sufficient to coaxially accommodate a tubular vessel (not shown) to be stapled to the aorta. Driver rod  406 , having threaded end  412  and handle  414 , extends through bore  416  of handle  402 . 
     Stapler  400  also comprises staple cartridge  418 , enlarged in FIG. 18 for purposes of describing its detail. Referring then to FIG. 18, there is shown the staple cartridge of FIG. 17 in its open position having top and bottom units  420  and  422 , respectively. Units  420  and  422  are engaged at one side by hinge  424  which allows cartridge  418  to be opened and closed. Staple cartridge  418  has two parallel bores  426  and  428  with inner circumferences sufficient to coaxially accommodate vessel rod  404  with a coaxially accommodated vein (not shown) and driver rod  406 , respectively. Staple delivery end  430  extends from staple cartridge  418  along the axis of bore  426  to accommodate the everted end of a vein to be stapled. Bore  428  is internally threaded to be threadedly engagable with driver rod end  412 . 
     For a proper fit between units  420  and  422 , a detent-recess pair is provided having detent  432  extending from inner surface  434  of top unit  420  which mates with recess  436  within inner surface  438  of bottom unit  422 . To secure closing, a curved clip  440  is provided to fit around cylindrical casing  442  of bore  428 . 
     When in a closed position, staple cartridge  418  has cylindrical staple delivery means or staple shaft array (not shown) encased in staple delivery end  430  which mates with cylindrical driver pin array  444  mounted on driver  446 . Both the hollow shafts and the solid driver pins have height and width measurements that allow them to be slidably engagable with each other. Driver  446  is slidable along surface  448  of top unit  420  and surface  450  of bottom unit  422  to the point of engagement with shoulder  452  of top unit  420  upon which driver pin array  444  becomes engaged within the staple shaft array, projecting preloaded staples from the end of staple delivery end  430 . Shoulder  452  limits the engagement of driver pin array  444  so that the tissue being stapled is not overcompressed. Modifications of the this embodiment can employ mutually coacting stops or spring-loaded type configurations between the driver and staple cartridge to prevent against overcompression of the tissue. 
     FIG. 19 shows a front view of staple cartridge  418  in its closed position with top unit  420  engaged with bottom unit  422 . Clip  440  securely fits around cylindrical casing  442 . Staple deforming end or staple shaft array  454  is shown on the face of staple delivery end  430 . 
     FIGS. 20-28, with like numbers referencing like elements, depict the various steps of the anastomotic procedure using the structural embodiment in FIGS. 17-19 described above. Referring now to FIG. 20, vessel rod  500  is inserted through aorta  502  of heart  504  via incisions  506  and  508  on opposing walls of aorta  502  such that anvil  510  is centrally positioned within aorta  502 . 
     In FIG. 21, the end of vessel rod  500  is then inserted into the distal end of vein  512  with anvil  510  still centrally positioned within aorta  502 . Next, as shown in FIG. 22, vessel rod  500  with accommodated vein  512  is positioned within the corresponding bore  514  in open staple cartridge  516 . Rod  500  and vein  512  should be positioned such that a sufficient length of distal end  518  of vein  512  extends beyond the end of cartridge  516  such that distal end  518  can be everted over cylindrical sleeve  520  of cartridge  516  (See FIG.  23 ). Once vein  512  has been optimally positioned, staple cartridge  516  is clamped around it and secured with clip  522 , illustrated in FIG.  24 . Now, distal end  518  of vein  512  is everted over sleeve  520  and is securely tied with string  524 . 
     Referring now to FIG. 25, driver rod  526  is slid into bore  528  of handle  530  and then threadedly engaged with bore  532  of staple cartridge  516 . FIG. 26 shows a close-up of staple cartridge  516  as it appears in its closed position. 
     Moving now to FIG. 27, there is shown driver handle  534  rotated in a clockwise direction, bringing together anvil  510  and cylindrical sleeve  520 . The clockwise rotation is continued until the aorta wall  502  is engaged with the distal end  518  of vein  512  upon which the staple driver pins (not visible) are fully engaged within each of the corresponding staple shafts (not visible), driving the staples (not visible) through the engaged tissue to create anastomotic bond  536  between aorta  502  and vein  512  (See FIG.  28 ). 
     In another aspect of the present invention, as viewed in FIGS. 29-37 with like numbers referencing like elements, an end-to-side surgical anastomosis apparatus, generally designated  600 , and procedure for end-to-side anastomosis is provided for stapling an end  601  of a tubular tissue structure  602  to a side portion of a luminal structure  603  (FIG.  37 ). The anastomosis apparatus  600  includes an elongated tubular housing or eversion mandrel, generally designated  605 , defining a central bore  606  extending longitudinally therethrough and terminating at a bore opening  607  at a distal end of the tubular housing. The central bore  606  includes a transverse cross-sectional dimension sufficiently sized and configured for receipt of the tissue structure  602  therein in a manner positioning the end of the tissue structure through the bore opening. The elongated tubular housing further includes an eversion support surface, generally designated  608 , extending circumferentially about the bore opening  607  adjacent the distal end. This surface  608  is configured to retain and support an everted end  601  of the received tissue structure  602  in a position facing an intimal surface  610  of the tissue structure  602  in a radially outward direction. The anastomosis apparatus  600  further includes an anvil  611  having a fastener engaging surface  612  positioned in the eversion support surface, and a plurality of fasteners  615  (FIG. 30) coupled to the apparatus. A compression device, generally designated  613 , is included having a shoulder portion  616  formed for selectively compressing the everted end  601  of the tissue structure  602  and a surface of the luminal structure  603  together against the fastener engaging surface  612 . Preferably, at least one driver pin  617  is provided moveable relative to the compression device  613  for ejecting the plurality of deformable fasteners from the compression device, through the everted end of the tubular tissue structure and the luminal structure to engage the fastener engaging surface. This engagement deforms the fasteners and creates an anastomotic bond between the tubular tissue structure and the luminal structure. 
     While this configuration still requires the end of the grafted tubular tissue structure  602  to be everted over the distal end of the mandrel (i.e. the everted end) for positioning against the eversion support surface  608 , the fastener engaging surface  612  of the anvil  611  is positioned on the eversion support surface  608  adjacent the bore opening  607 . Hence, unlike the previous embodiments of the present invention, the everted end of the tubular tissue structure is everted over the anvil structure as well. 
     In this embodiment, the deformable fasteners  615  are preferably provided by conventional staples formed to pierce through the tissues to be anastomotized. Other deformable fasteners, however, could be employed such as deformable clips or the like. Accordingly, fastener engaging surface  612  is preferably provided by a plurality of pairs of fastener deforming recesses circumferentially spaced about bore opening  607  (FIGS.  30  and  31 ). Each deforming recess  612  is similar in function and shape as the fastener deforming recesses in the embodiment illustrated in FIG.  4 . Further, the fastener engaging surface  612  (i.e. deforming recesses) of this embodiment is preferably integrally formed and recessed in the eversion support surface  608  of the mandrel  605 . When the everted end  601  of the tubular tissue structure  602  is resiliently everted over the mandrel distal end and into supportive contact with the eversion support surface  608 , accordingly, the fastener engaging surface  612  is positioned underneath the adventitial surface  620  of the everted tissue. 
     The everted end  601  is maintained and retained in the everted condition against the eversion support surface  608  by the resiliency of the tubular tissue structure. This is performed by sufficiently sizing the transverse cross-sectional dimension of the eversion support surface, relative the transverse cross-sectional dimension of the tubular tissue structure, for resilient cooperation therebetween. It is important, however, that the transverse cross-sectional dimension of the eversion support surface be sufficiently small to ensure that the structural integrity of the everted end will not be compromised when everted over the mandrel distal end. 
     In addition, a securing device may be included to maintain the everted end of the tubular tissue everted over the end of the eversion mandrel. For example, a plurality of tines or the like may protrude outwardly from the eversion support surface which penetrate and retain the everted tissue over the distal end of the mandrel in the everted condition. Furthermore, a suture may be provided to removably secure or tie the everted end to the eversion support surface. 
     To assure that the fastener engaging surface  612  is positioned for engagement with the fasteners or staples  615  ejected from the compression device  613 , the recesses  612  are situated at a portion of the eversion support surface which faces in the direction of the staple shoulder portion  616 . This alignment enables engagement and deformation of a respective staple  615  with the respective deforming recess upon ejection thereof from compression device  613 . In the bell-shaped eversion support surface  608  illustrated in FIG. 32 (to be discussed below), the fastener engaging surface  612  is situated along a lower annular rim portion  621  of the support surface  608 . 
     Referring now to FIG. 33, it is shown that the central bore is generally linear extending longitudinally through mandrel  605  parallel to the longitudinal axis thereof. Bore  606  is sufficiently sized and configured for receipt of the tubular tissue structure  602  therein without substantially deforming or damaging the tissue structure during loading of the tissue therein, and is of a length sufficient to accommodate the free graft intended for use. Further, the central bore terminates at the central bore opening  607  at the distal end of the eversion mandrel  605 . Before eversion of the everted end of the tubular tissue structure over the distal end of the eversion mandrel or tubular housing  605 , the tubular tissue structure must be properly positioned in the central bore  606  where the distal end of the tubular tissue structure protrudes past the distal end of the eversion mandrel. This extension beyond the mandrel or tubular housing distal end must be an amount sufficient to enable the eversion of the tubular tissue structure  602  over the fastener engaging surface  612  of the anvil  611 . 
     To anastomotize attached graft tubular tissue structures having only one free unattached end, such as an Internal Mammary Artery (IMA) graft or the like, a side port  622  is provided at a side wall portion of the eversion mandrel  605  which communicates with the central bore  606 . This port enables the attached graft tissue structure  602  to enter the central bore from the side of the eversion mandrel without requiring that the graft be free at both ends. FIG. 33 best illustrates that the attached graft tissue structure  602  enter side port  622 , extend through central bore  606  and exits bore opening  607  before being everted over the mandrel distal end for resilient support by eversion support surface  608 . The side port  622  is preferably circular or oval shaped in cross-sectional dimension, and curving inwardly toward the central bore. The port, however, may be virtually any other shape which is sufficiently sized for the passage of the tubular tissue structure therethrough. It will be understood that both the central bore and the side port should be free of any sharp edges or the like which are likely to cause any cutting, nicking or any inadvertent damage to the loaded tubular tissue structure during operation of the anastomosis apparatus. 
     To facilitate the delicate placement of the tubular tissue structure  602  in the elongated central bore  606 , the mandrel  605  is formed to move to an opened condition for increased access and exposure of all or a substantial portion of the central bore  606 . This is accomplished by providing a clam shell type design for the lower end portion of the eversion mandrel  605 , similar in concept to the embodiment set forth in FIG.  23 . In the preferred embodiment, the lower end portion of mandrel  605  is divided into a first half  605 ′ and a second half  605 ″ which are pivotally coupled together for pivotal movement between an opened condition (FIG. 33) and a closed condition (FIG.  29 ). In the open condition, the mandrel or tubular housing  605  is pivotally opened to expose, substantially longitudinally, the central bore  606  so that the tubular tissue structure  602  may be easily positioned therein. In the closed condition, the lower end portion of the eversion mandrel closes over the loaded tubular tissue structure to enclose the same in the central bore  606 . 
     The first and second halves  605 ′,  605 ″ are preferably mirror-images of one another and are semi-cylindrical in shape. Each eversion mandrel half further defines one half of the central bore  606  (i.e., a semi-cylindrical first and second bore half  606 ′,  606 ″) which collectively cooperate to form the bore when the mandrel is moved to the closed condition. The relative pivotal movement is provided by a longitudinally extending hinge  623  (FIGS. 33 and 34) pivotally coupling the first half  605 ′ to the second half  605 ″. Preferably, hinge  623  includes an elongated pin or gudgeon member  625  extending longitudinally along an edge of one of the mandrel halves generally parallel to the central bore, while the other mandrel half defines an elongated socket  626  extending longitudinally along an opposing edge of the same. Each of the gudgeon member  625  and mating socket  626  are integrally formed with the respective mandrel half, and each is sized and configured relative one another for mating pivotal coupling therebetween. Hence, once slidably coupled, as shown in FIG. 34, the opposing mandrel halves  605 ′,  605 ″ matingly engage and cooperatively pivot between the opened condition (FIG. 33) and the closed condition (FIG.  29 ). 
     In accordance with the present invention and as will be described in greater detail below, the compression device  613  is coupled to eversion mandrel  605  for sliding movement longitudinally along the mandrel between a released condition (FIG. 33) and a compressed condition (FIG.  36 ). Briefly, in the released condition, the eversion mandrel is permitted to move between the closed condition and the opened condition, enabling loading of the tissue structure in the central bore. In the compressed condition, the staple apparatus  600  selectively compresses an intimal surface  610  of the everted end  601  of the tissue structure  602  to an intimal surface  627  of the luminal structure  603 . 
     To prevent interference with the sliding movement of the compression device  613  by the hinge  623 , the hinge is preferably recessed from the exterior surface  630  of the mandrel  605 . As best viewed in FIG. 34, both the gudgeon member  625  and the socket  626  are positioned along opposing edge walls  628 ′,  628 ″ of the respective first and second mandrel halve  605 ′,  605 ″ between the respective exterior surface  630 ′,  630 ″ and the central bore half  606 ′,  606 ″ thereof. Accordingly, the hinge  623  does not protrude into the path of the compression device  613  to impede movement as the assembly slides over the hinge  623  between the released and compressed conditions. 
     It will be appreciated that a variety of other hinges or coupling devices could be employed without departing from the true spirit and nature of the present invention. Moreover, a hinge could be provided which does protrude into the path of sliding movement of the compression device (not shown) which would normally impede the movement to the compressed condition. In this arrangement, the protruding hinge may function as both a hinge and as a key member or the like for an alignment mechanism  631  (to be discussed later) to align movement of the compression device  613  relative the eversion mandrel  605 . 
     To enable pivotal movement of the mandrel halves  605 ′,  605 ″ between the closed and the opened conditions, at least one of, and preferably both, the opposing edge walls  628 ′,  628 ″ includes a tapered wall portion  632 ′,  632 ″ which tapers away from the opposing edge wall. The collective angle of tapered wall portions  632 ′,  632 ″ will determine the relative pivotal movement between the mandrel halves  605 ′,  605 ″ about the hinge member  623 . In the preferred embodiment, these opposing tapered wall portions  632 ′,  632 ″ are adapted to limit the pivotal movement of the mating halves  605 ′,  605 ″ in the opened condition (phantom lines in FIG. 34) between about 45° to about 120°. This opening angle need only be sufficiently large to enable positioning of the attached or free graft into the exposed central bore  606 . Since the diameter of these grafts are relatively small, the opening angle need not be very large. 
     Once the tubular tissue structure is properly positioned in the one side of the semi-cylindrical bore portion, while the eversion mandrel is in the opened condition (FIG.  33 ), the mandrel halves  605 ′,  605 ″ are moved to the closed condition (FIG. 29) enclosing the tubular tissue in the central bore. By positioning the distal end of the tubular tissue structure  602  beyond the distal end of the eversion mandrel (FIG.  33 ), the everted end  601  of the tissue structure can be everted back over the distal end of the mandrel either through manually rolling the tissue onto the generally spherical shaped eversion support surface or through the assistance of medical instruments. 
     As best shown in FIG. 30, it is imperative that the everted tissue extend over the anvil  611  so that the fastener engaging surface  612  is positioned beneath the adventitial surface  620  of the everted tissue structure. Preferably, the everted end is of a length sufficient to enable the distal end to terminate at a neck portion  633  of the eversion support surface  608  which is positioned rearward of the fastener engaging surface  612 . By tapering the neck portion  633  inwardly from the eversion mandrel exterior surface  630 , contact of the tissue structure distal end with the sliding compression device  613  will be prevented when the compression device is moved to the compressed condition. 
     When the eversion mandrel is moved to the closed condition, the transverse cross-sectional dimension of the central passage  635  of the compression device  613  is sized and dimensioned for longitudinal sliding receipt of mandrel therein. As above mentioned, the lower end portion of the eversion mandrel is slidably received in the central passage  635  of the compression device  613  between a released condition and a compressed condition. In the released condition (FIG.  33 ), the compression device  613  is moved to a position, relative the eversion mandrel, which will not impede the movement of the mandrel half  605 ′,  605 ″ between the opened and closed conditions. Accordingly, in the released condition, the mandrel half portions can be pivotally moved to the opened condition so that the attached or unattached grafted tubular tissue structure can be either loaded or removed from the exposed central bore  606 . 
     In contrast, in the compressed condition, the compression device  613  is moved slidably and longitudinally along the exterior surface of eversion mandrel  605  toward the eversion support surface  608  until the tissue structures to be anastomotized are compressed between the shoulder portion  616  of the compression device  613  and the eversion support surface  608  of the eversion mandrel. As shown in FIG. 37, the everted end of the tissue structure  602  mounted to the distal end of eversion mandrel  605  is moved forwardly through the surgically formed opening  636  in the side of the luminal structure  603  until the distal end of the mandrel is positioned in the luminal structure. It is noted that the surgically formed opening  636  in the resilient luminal structure is preferably smaller in cross sectional dimension than that of the eversion support surface  608 . Once the distal end of the mandrel  605  and the everted tissue structure  601  mounted thereon are positioned in the luminal structure  603 , the two are retracted rearwardly as a unit until the intimal surface  610  of the everted tissue structure  602  contacts the intimal surface  627  of the luminal structure  603  adjacent the surgically formed opening  636 . Due to the resilient nature of the tissue, circumferential contact between the adjacent tissue structures is facilitated. Hence, upon proper positioning of the everted end of the tubular tissue structure and the lower end of the eversion mandrel through the surgically formed opening  636  (FIGS.  36  and  37 ), the intimal surface  610  of the everted tubular tissue structure  602  circumferentially contacts the intimal surface  627  of the luminal structure  603  adjacent the fastener engaging surface  612 . The compression device  613  can then be moved to the compressed condition, compressing the everted end of the tissue structure and the tissue of the luminal structure  603  between the shoulder portion  616  of the compression device  613  and the eversion support surface  608  of the eversion mandrel  605 . Subsequently, the stapler compression device can be prepared for ejecting or firing the staples therefrom to form an intimal-to-intimal surface anastomotic bond. 
     Accordingly, using the method and anastomosis apparatus of the present invention, the end-to-side anastomotized tissues juncture will be free of any portion of the fastener protruding into the lumen of either the graft vessel or target vessel to interfere with blood flow (FIG. 38) This arrange will reduce the risk of thrombus formation. 
     Employing a concept similar to the previous embodiments, compression device  613  includes a disposable circular staple cartridge  637  encasing a circular array of staple delivery shafts  638 . The shafts  638  may be arranged in a plurality of concentric arrays or rows of staple shafts to best perform these anastomotic procedures. Although the present invention is primarily described and depicted as forming staple bonds that are circular and as having component circumferences that are circular, other embodiments are realized for forming staple bonds having elliptical, tear drop, generally oval or other non-circular shapes. Accordingly, the anvil and associated array of deforming recesses  612  (i.e. the fastener engaging surface  612 ), and the staple cartridge  637  and associated staple shaft array of these alternative stapler embodiments have circumferences in the shape of the desired staple bond. 
     Referring now to FIGS. 29 and 35, compression device  613  is shown including a tubular drive housing  640  operatively coupled to staple cartridge  637  for driving staples from the cartridge  637  into engagement with the fastener engaging surface  612  positioned on eversion mandrel  605 . The drive housing  640  and the staple cartridge  637  each define a segment of central passage  635  which as mentioned is formed for sliding receipt of the eversion mandrel therein. 
     To promote alignment between the array of staple shafts  638  and the corresponding staples  615  therein, and the respective fastener deforming recesses  612 , an alignment mechanism  631  may be provided operatively positioned between the eversion mandrel and the compression device  613  and the drive housing  640 . Preferably, as best viewed in FIG. 29, the alignment mechanism  631  is provided by a key member  641  protruding into the central passage  635  from an interior wall of the compression device (i.e., either the staple cartridge  637 , the driver housing  640 , or both), and a longitudinally extending groove  642  provided in the exterior surface of the eversion mandrel  605 . The key member  641  is formed and dimensioned for sliding receipt in the alignment groove  642  for aligned movement of the staple cartridge  637  relative the eversion mandrel  605 . It will be understood that the eversion mandrel could include a key member while the compression device defines the groove, or that any other alignment mechanism could be employed to align the two components without departing from the true spirit and nature of the present invention. For example, as set forth above, the key member could be provided by a protruding hinge member of the eversion mandrel protruding into the central passage of the compression device. 
     Mounted to and protruding perpendicularly outward from the face  643  of drive housing  640  is a plurality staple driver pins  617  aligned in an array (circular in FIGS. 29 and 35) conforming to the delivery shaft pattern of the staple cartridge  637 . Staple cartridge  637  encases, from end to end, a cylindrical array of hollow staple delivery shafts  638  each of which hold a preloaded staple  615 . All shafts  638  are identical and each has height and width dimensions such that a corresponding staple driver pin  617  is slidable therein. In the configuration of the FIG. 30, due to the position and orientation of the deforming recesses  612  positioned on the eversion support surface  608 , the staples  615  are preferably ejected from the cartridge housing at about a 30° to about 60° angle, and most preferably about 45° angle, from the vertical. This angle assures that the staples penetrate the tubular tissue and the luminal tissue generally perpendicular thereto to form a proper anastomotic bond. 
     Each staple shaft  638 , thus, will curve inwardly from a direction parallel to the longitudinal axis of the central passage  635  to the desired angle toward the axis. Hence, to slidable accommodate such a curvature, the driver pins  617  will have to be resiliently flexible in nature. For example, the driver pins may be composed of stainless steel, plastic or the like. 
     The staple cartridge  637  is preferably provided by a disposable cartridge which is disposed of and replaced after one anastomotic stapling. This assures that the staple shafts and central passages are clean, sterile and clear of blockage during operation. In another embodiment, a slidable sleeve not shown) may be provided around the driver pin array to prevent blood and tissue from getting caught therein. 
     Again, it is imperative not to injure the living tissue being stapled by overcompressing it between the fastener engaging surface  612  of anvil  611  and the shoulder portion  616  of the staple cartridge  637 , or by a staple bond that is exceedingly tight. Accordingly, overcompression of the tissue is again prevented in this embodiment of the present invention by limiting the length of driver pins  617 . 
     Similar to the embodiment of FIG. 7, a threaded proximal end of eversion mandrel  605  may be provided which extends beyond the length of the delivery housing  640  (not shown) to threadedly engage with a nut. This nut may include an internally threaded throughbore extending the full length of cylindrical nut which allows the threaded end to exit therethrough. 
     Moreover, an off-set assembly may be employed to control the movement of the compression device  613  between the compressed condition and the released condition. Briefly, in this configuration (not shown; however similar to but in the reverse direction of the off-set mechanism employed in the embodiment of FIGS.  17  and  18 ), eversion mandrel  605  (handle  402 ) is slidably received in the central passage  635  of compression device  613  (staple cartridge  418 ). An off-set housing portion (cylindrical casing  442 ) of compression device  613  is movably coupled to and cooperating with an off-set driver rod (driver rod  406 ), axially off-set from eversion mandrel  605 , to drive the movement of the compression device between the released and the compressed conditions. Similar to the off-set mechanism of FIGS. 17 and 18, the driving force may be provided by a threaded end (driver rod end  412 ) or a threaded handle portion (handle  402  at bore  416 ) whereby the off-set housing portion of compression device  613  would be rigidly coupled to the off-set driver rod (driver rod  406 ). 
     Both the staple cartridge  637  and the delivery housing  640  may incorporate a clam-shell design in which each housing provides a semi-cylindrical half portion ( 637 ′,  637 ″ for cartridge  637 , and  640 ′,  640 ″ for delivery housing  640 ). Each half portion of the compression device is preferably hingedly mounted together. through independent hinge members, at a respective edge portion, similar to the eversion mandrel. The half portions, however, may be simply snapfit together as well. In either configuration, the half portions will be independently, or cooperatively, movable between an opened position (not shown) and a closed position (FIG.  35 ). In the opened condition, the respective half portions are cooperatively pivoted along a pivotal axis of the hinge members, parallel to the longitudinal axis of the central passage. This pivotal movement will pivot the corresponding half portions, and away from one another to expose the central bore  606 . The relative pivotal movement of the housing half portions is by an amount sufficient to enable receipt of the eversion mandrel  605  in the central passage  635  when the eversion mandrel is in the closed condition. 
     In the closed position of the compression device, as illustrated in FIG. 35, the housing half portions ( 637 ′,  637 ″ for cartridge housing  637 , and  640 ′,  640 ″ for delivery housing  640 ) are enclosed about the loaded eversion mandrel. This arrangement enables sliding receipt of the eversion mandrel  605  from the released condition to the compressed condition before firing of the staples from the staple shafts. 
     To accommodate attached grafts, the delivery housing includes an elongated delivery slot  645  in alignment with side port  622  of the eversion mandrel for receipt of the attached end of the graft therethrough. As best viewed in FIG. 35, slot  645  is sufficiently sized and configured to enable movement of the delivery housing between the released and the compressed conditions. Accordingly, slot  645  is relatively linear and generally extends in a direction parallel to the mandrel longitudinal axis from one end of the proximal end to the distal end of the delivery housing. 
     FIGS. 36-38 illustrate the mechanical interaction between the staple driver pins  617 , staple cartridge  637  and eversion mandrel anvil  611  upon operational engagement therebetween. In accordance with the present invention, after the graft has been loaded into the central bore of the eversion mandrel, and the everted end thereof has been everted over the distal end of the mandrel, the compression device can be moved to the closed position. In this configuration, before the assembly is moved to the compressed condition, the array of staple delivery pins  617  mounted on face  643  of delivery housing  640  are slidably engaged within the array of staple delivery shafts  638  of staple cartridge  637 . The array of staples  615  is projected from staple cartridge  637  and through the tissues to be stapled (not shown). Similar to FIG. 9, once the driver pins  617  contact the respective staples  615 , the staples are ejected or fired from the staple shafts and driven through the tubular tissue structure and the luminal tissue adjacent the surgically formed opening until the staples contact and are deformed by the deforming recesses  612  to form an intimal-to-intimal anastomotic bond. 
     Moreover, a spring-loaded engagement between the compression device  613  and the eversion mandrel  605  enabling independent compression of the tissues, and independent stapling thereof is also preferably applicable for this embodiment of the present invention. Such a stapler device is illustrated in commonly owned and co-pending U.S. patent application Ser. No. 08/597,691, filed Feb. 6, 1996, hereby incorporated by reference in its entirety. This arrangement enables independent compression of the tissues between the compression device shoulder portion  616  and the anvil  611  of the eversion mandrel  605  before the firing step commences, firing or ejecting the staples through the tissues. This assures that the overcompression of the tissues does not occur during the firing step. 
     As above-mentioned and as shown in FIG. 32 eversion support surface  608  may be bell-shaped having a distal end of the eversion mandrel  605  which tapers outwardly. In this embodiment, the fastener engaging surface  612  (i.e., the deforming recesses) is positioned circularly about bore opening  607  on lower annular rim portion  621 . The annular rim portion  621  is oriented generally perpendicular to the direction of travel of the compression device  613  so that the deforming recesses face the corresponding staple shafts  638  perpendicularly without requiring any curvature of the shafts. 
     Similar to the previous embodiment, the everted end of the tubular tissue structure is everted over the distal end of the eversion mandrel  605  so that the adventitial surface  620  of the tissue structure is resiliently supported against the fastener engaging surface. It will further be appreciated that in either the generally spherically shaped eversion support surface or the bell-shaped eversion support surface, the transverse cross-sectional dimension of the eversion support surface  608  is larger than the transverse cross-sectional dimension of the central passage  635 . This arrangement prevents the compression device from slipping past the end of the eversion support surface when the mandrel is operatively positioned in the compressed condition (FIGS.  32  and  36 ). 
     It will be understood that the foregoing is only illustrative of the principles of the present invention, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. For example, the particular stapler structural configurations shown are not critical and other configurations can be used if desired. One possible alternative for the configuration illustrated in FIG. 17 is to have a vessel rod that is retractable (e.g., by means of a telescoping rod). In addition, the vessel rod of this alternative embodiment can be curved to facilitate the anastomotic procedure if necessary. Also, the structure and method of the present invention can be employed thoracoscopically.