Abstract:
Minimally invasive techniques utilized in bypass grafting are disclosed. For instance, a method of implanting an end portion of a graft in the body of a patient during a bypass grafting procedure includes the steps of (i) advancing a medical instrument within a circulatory system of said body, (ii) guiding a distal end of said medical instrument out of said circulatory system through an opening defined in said circulatory system after said medical instrument advancing step, (iii) advancing said end portion of said graft within said medical instrument after said guiding step, and (iv) securing said end portion of said graft to a blood vessel of said circulatory system after said end portion advancing step.

Description:
RELATED CASES 
     This application is a continuation of application Ser. No. 09/111,062 filed Jul. 7, 1998, now abandoned, which is a continuation of application Ser. No. 09/090,598 filed Jun. 4, 1998, now U.S. Pat. No. 5,934,286, which is a continuation of application Ser. No. 09/073,336 filed May 5, 1998, now U.S. Pat. No. 5,979,455, which is a continuation of application Ser. No. 08/702,742 filed Aug. 23, 1996, now U.S. Pat. No. 5,749,375, which is a continuation of application Ser. No. 08/391,960 filed Feb. 21, 1995, now U.S. Pat. No. 5,571,167, which is a continuation of application Ser. No. 08/138,912 filed Oct. 18, 1993, now U.S. Pat. No. 5,456,712, which is a division of application Ser. No. 08/056,371 filed on May 3, 1993, now U.S. Pat. No. 5,304,220, which is a continuation-in-part of application Ser. No. 07/725,597 filed on Jul. 3, 1991, now U.S. Pat. No. 5,211,683. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a method for improving blood flow in the body of a patient and more particularly concerns an extravascular bypass grafting method which utilizes an intravascular approach. 
     Treatment of vascular disease in which the lumen of a blood vessel is significantly narrowed or occluded by atherosclerosis includes surgical and endovascular methods. Conventional surgical methods include obtaining access to a blood vessel via one or more surgical incisions and either removing the blockage by performing an endarterectomy or bypassing the blockage by placing a bypass graft which has a generally cylindrical shape. Endovascular methods include obtaining access to a blood vessel with a catheter and improving blood flow therein by performing an athrectomy, atherolysis, or balloon and laser angioplasty with or without endovascular stent placement. In general, the preferred treatment of severe stenosis or occlusion of a long vessel segment has been surgical bypass grafting. 
     Although conventional surgical bypass grafting is an accepted procedure, it presents substantial morbidity and mortality risks. Also, not all patients are acceptable candidates for the above surgical procedure due to advanced age and preexisting medical conditions. Moreover, conventional surgical bypass grafting is an invasive procedure which may require extended hospitalization due to postoperative recovery. In addition, the above surgical procedure may involve substantial financial costs to patients, hospitals and society in general. Further, incisions made during the above surgical procedure may cause significant cosmetically unattractive scarring which is undesirable to many patients. 
     SUMMARY OF THE INVENTION 
     One embodiment of the present invention involves a method of implanting a graft prosthesis in the body of a patient to bypass a segment of a blood vessel. The method includes the steps of (1) making an incision in the body, (2) positioning a graft so that one end of the graft is located substantially adjacent the blood vessel at a site upstream of the segment and a second end of the graft is located substantially adjacent the blood vessel at a site downstream of the segment, wherein the positioning step includes the step of placing the graft into the body through the incision, and further wherein the positioning step is performed while the upstream site is covered by a substantially intact portion of the epidermis of the body, (3) isolating a region of the area within the blood vessel substantially adjacent the upstream site from fluid communication with the rest of the area within the blood vessel, wherein the upstream isolating step is performed while the upstream site is covered by the substantially intact portion of the epidermis of the body, (4) making an arteriotomy in a sidewall of the blood vessel substantially adjacent the upstream site to create a communicating aperture between the upstream isolated region and an area outside of the blood vessel, wherein the upstream arteriotomy making step is performed while the upstream site is covered by the substantially intact portion of the epidermis of the body, (5) forming an anastomosis between the one end of the graft and the blood vessel substantially adjacent the upstream site, wherein the upstream anastomosis forming step is performed while the upstream site is covered by the substantially intact portion of the epidermis of the body, and further wherein the upstream anastomosis forming step includes the step of suturing the one end of the graft to the blood vessel, (6) isolating a region of the area within the blood vessel substantially adjacent the downstream site from fluid communication with the rest of the area in the blood vessel, (7) making an arteriotomy in the sidewall of the blood vessel substantially adjacent the downstream site to create a communicating aperture between the downstream isolated region and the area outside of the blood vessel, and (8) forming an anastomosis between the second end of the graft and the blood vessel substantially adjacent the downstream site. 
     Another embodiment of the present invention involves a method for implanting an end portion of a graft within the body of a patient during a bypass grafting procedure. The method includes the steps of (1) making an incision in the body at a first location, (2) isolating a region of the area within a blood vessel of the body substantially adjacent a second location from fluid communication with the rest of the area within the blood vessel, wherein the first location is remote from the second location, and further wherein the isolating step is performed while the second location is covered by a substantially intact portion of the epidermis of the body, (3) making an arteriotomy in the sidewall of the blood vessel substantially adjacent the second location to create a communicating aperture between the isolated region and the outside of the blood vessel, wherein the arteriotomy making step is performed while the second location is covered by the substantially intact portion of the epidermis of the body, (4) advancing the end portion of the graft through the incision to the second location, wherein the advancing step is performed while the second location is covered by the substantially intact portion of the epidermis of the body, and (5) forming an anastomosis between the end portion of the graft and the blood vessel substantially adjacent the second location, wherein the anastomosis forming step is performed while the second location is covered by the substantially intact portion of the epidermis of the body, and further wherein the anastomosis forming step includes the step of suturing the end portion of the graft to the blood vessel. 
     Still another embodiment of the present invention involves a graft which is securable to a sidewall of a blood vessel having an arteriotomy defined therein. The graft includes a body portion, and a flanged end portion attached to the body portion, the flanged end portion being positionable substantially adjacent a portion of the sidewall of the blood vessel which substantially surrounds the arteriotomy. 
     Yet another embodiment of the present invention involves a graft and stent assembly which is securable to a sidewall of a blood vessel having an arteriotomy defined therein. The graft and stent assembly includes a graft having an end portion which is positionable within the blood vessel and substantially adjacent a portion of the sidewall of the blood vessel which substantially surrounds the arteriotomy. The graft and stent assembly further includes a stent positionable within the blood vessel and in contact with the end portion of the graft so as to secure the end portion of the graft between the sidewall of the blood vessel and the stent. 
     One object of the present invention is to provide an improved method for implanting a graft prosthesis in the body of a patient. 
     Another object of the present invention is to provide an improved method for implanting an end portion of a graft within the body of a patient. 
     Still another object of the present invention is to provide a method of implanting a graft prosthesis in the body of a patient which is less invasive relative to conventional surgical bypass grafting procedures. 
     Yet another object of the present invention is to provide a method of implanting a graft prosthesis in the body of a patient which obviates at least one surgical incision (e.g. the abdominal surgical incision) as compared to conventional surgical bypass grafting procedures. 
     Still another object of the present invention is to provide a method of implanting a graft prosthesis in the body of a patient which has low morbidity and mortality risk to patients. 
     Yet another object of the present invention is to provide a method of implanting a graft prosthesis in the body of a patient which can be performed on patients whom are elderly or have poor preexisting medical conditions. 
     Still another object of the present invention is to provide a method of implanting a graft prosthesis in the body of a patient which requires relatively less financial costs to patients, hospitals and society in general as compared to conventional surgical bypass grafting techniques. 
     Yet another object of the present invention is to provide an improved graft prosthesis. 
     Still another object of the present invention is to provide an improved graft and stent assembly. 
     Another object of the present invention is to provide a graft which can be conveniently secured to a blood vessel. 
     Yet another object of the present invention is to provide a graft and stent assembly which allows the graft to be conveniently secured to a blood vessel. 
     Yet still another object of the present invention is to provide a graft which is easy to implant in the body of a patient. 
     Still another object of the present invention is to provide a graft and stent assembly which is easy to implant in the body of a patient. 
     Another object of the present invention is to provide a graft which functions well after it is implanted in the body of a patient. 
     Yet another object of the present invention is to provide a graft and stent assembly which functions well after it is implanted in the body of a patient. 
     Other objects and benefits of the present invention can be discerned from the following description and accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary front elevational view of a human body showing a blood vessel which includes the aorta, the right common iliac artery, the right common femoral artery and the left common femoral artery wherein a segment of the blood vessel is occluded. FIG. 1 also shows a portion of each inguinal ligament of the human body. 
     FIG. 2 is an enlarged fragmentary view of the human body and blood vessel of FIG.  1 . 
     FIG. 3 shows the human body and blood vessel of FIG. 2 with a balloon-tip catheter positioned within the blood vessel wherein the balloon is inflated in accordance with the preferred method of the present invention. 
     FIG. 4 is a view similar to FIG. 3 but showing a second balloon-tip catheter positioned within the blood vessel wherein the second balloon is inflated in accordance with the preferred method of the present invention. 
     FIG. 5 is a view similar to FIG. 4 but showing the blood vessel in phantom except for a portion thereof that is exposed through a gaping surgical incision. Also shown exposed through the surgical incision in FIG. 5 is a portion of the right inguinal ligament. 
     FIG. 6 is a view similar to FIG. 5 but showing another portion of the blood vessel, including the aorta, exposed for clarity of description. Moreover, in FIG. 6, a laparoscope (depicted schematically) is shown inserted through the surgical incision in accordance with the preferred method of the present invention. 
     FIG. 7 is a view similar to FIG. 6 but showing a needle positioned within the laparoscope in accordance with the preferred method of the present invention. 
     FIG. 8 is a view similar to FIG. 7 but showing the needle removed from the laparoscope and replaced with a scissors device in accordance with the preferred method of the present invention. 
     FIG. 9A is an elevational view of a graft prosthesis used in carrying out the preferred method of the present invention. 
     FIG. 9B is a fragmentary sectional view. taken along the line  9 B— 9 B of FIG. 9A as viewed in the direction of the arrows. 
     FIG. 9C is a fragmentary perspective view of the graft prosthesis of FIG. 9A showing its outwardly extending flanged end portion. 
     FIG. 9D is another fragmentary perspective view of the graft prosthesis of FIG. 9A showing its outwardly extending flanged end portion. 
     FIG. 9E is a view similar to FIG. 9C but showing a plurality of springs, in phantom, integrally positioned within the outwardly extending flanged end portion, in addition to, a portion of the sidewalls of the graft prosthesis of FIG.  9 A. 
     FIG. 9F is an elevational view of one of the plurality of springs of FIG.  9 E. 
     FIG. 9G is an elevational view of another of the plurality of springs of FIG.  9 E. 
     FIG. 9H is an elevational view of yet another of the plurality of springs of FIG.  9 E. 
     FIG. 9I is an elevational view of still another of the plurality of springs of FIG.  9 E. 
     FIG. 10A is an elevational view of the graft prosthesis of FIG. 9A wherein the graft prosthesis is in a rolled configuration. 
     FIG. 10B is a cross-sectional view taken along the line  10 B— 10 B of FIG. 10A as viewed in the direction of the arrows. 
     FIG. 11A is an elevational view of the laparoscope of FIG.  6 . Moreover, FIG. 11A shows the graft prosthesis of FIG. 10A, positioned within the laparoscope in accordance with the method of the present invention. FIG. 11A further shows a plunger, used in carrying out the preferred method of the present invention, partially positioned within the laparoscope in accordance with the preferred method of the present invention. 
     FIG. 11B is a cross-sectional view taken along the line  11 B— 11 B of FIG. 11A as viewed in the direction of the arrows. 
     FIG. 12 is a view similar to FIG. 8 but showing the scissors device removed from the laparoscope and replaced with the graft prosthesis and plunger of FIG. 11A in accordance with the preferred method of the present invention. 
     FIG. 13 is a view similar to FIG. 12 but showing the graft prosthesis being advanced out the distal end of the laparoscope in accordance with the preferred method of the present invention. 
     FIG. 14 is a view similar to FIG. 13 but showing the graft prosthesis being further advanced out the distal end of the laparoscope in accordance with the preferred method of the present invention. 
     FIG. 15 is a view similar to FIG. 14 but showing the graft prosthesis being yet further advanced out the distal end of the laparoscope in accordance with the preferred method of the present invention. 
     FIG. 16 is a view similar to FIG. 15 but showing the laparoscope removed from the surgical incision and showing the graft prosthesis after it had reverted back to its prerolled configuration in accordance with the preferred method of the present invention. 
     FIG. 17 is a view similar to FIG. 16 but showing a third balloon-tip catheter having a balloon thereon and further having an expandable stent, in its unexpanded state, positioned over the balloon, advanced to a position within the blood vessel in accordance with the preferred method of the present invention. 
     FIG. 18 is a view similar to FIG. 17 but showing the balloon of the third balloon-tip catheter inflated so as to expand the stent in to its expanded configuration in accordance with the preferred method of the present invention. 
     FIG. 19A is a view similar to FIG. 18 but showing the third balloon-tip catheter removed from the blood vessel and showing the stent expanded to form an anastomosis between one end of the graft prosthesis and the blood vessel in accordance with the preferred method of the present invention. 
     FIG. 19B is an enlarged schematic side elevational view showing a number of sutures tied to the sidewall of the blood vessel so as to secure the end portion of the graft and the stent thereto as a possible additional procedure in order to further ensure the integrity of the anastomosis of FIG.  19 A. 
     FIG. 19C is a cross-sectional view taken along the line  19 C— 19 C of FIG. 19B as viewed in the direction of the arrows. 
     FIG. 19D is a view similar to FIG. 19A but showing a laparoscope (depicted schematically) inserted through an incision in the epidermis of the body and into the peritoneal cavity, and further showing a grasper holding a curved needle with an end of a suture attached thereto wherein the distal end of the grasper is positioned at the upstream site. 
     FIG. 19E is an enlarged schematic side elevational view showing a number of sutures tied to the sidewall of the blood vessel so as to secure the end portion of the graft thereto (without the use of the stent), wherein the end portion of the graft is positioned within the upstream isolated region, as an alternative procedure in forming an anastomosis between the end portion of the graft and the blood vessel. 
     FIG. 19F is a cross-sectional view taken along the line  19 F— 19 F of FIG. 19E as viewed in the direction of the arrows. 
     FIG. 19G is an enlarged schematic side elevational view showing a number of sutures tied to the sidewall of the blood vessel so as to secure the end portion of the graft thereto (without the use of the stent), wherein the end portion of the graft is positioned outside of the upstream isolated region, as another alternative procedure in forming an anastomosis between the end portion of the graft and the blood vessel. 
     FIG. 19H is a cross-sectional view taken along the line  19 H— 19 H of FIG. 19G as viewed in the direction of the arrows. 
     FIG. 20A is an enlarged side elevational view showing the anastomosis of FIG.  19 A. 
     FIG. 20B is a cross-sectional view taken along the line  20 B— 20 B of FIG. 20A as viewed in the direction of the arrows. 
     FIG. 20C is a cross-sectional view taken along the line  20 C— 20 C of FIG. 20A as viewed in the direction of the arrows. 
     FIG. 21 is a view similar to FIG. 19A but showing a pair of clamps positioned on the blood vessel in accordance with the preferred method of the present invention. 
     FIG. 22 is a view similar to FIG. 21 but showing an arteriotomy formed in the sidewall of the blood vessel in accordance with the preferred method of the present invention. 
     FIG. 23 is a view similar to FIG. 22 but showing an anastomosis formed between the other end the graft prosthesis and the blood vessel in accordance with the preferred method of the present invention. 
     FIG. 24 is a view similar to FIG. 23 but showing the first balloon-tip catheter and the second balloon-tip catheter removed from the blood vessel in accordance with the preferred method of the present invention. 
     FIGS. 25-33 are views showing performance of a bypass grafting procedure in accordance with the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments and methods illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated devices and methods, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
     Referring now to the drawings, FIG. 1 shows a portion of a human body, generally designated by the reference numeral  10 , with an artery, the common iliac artery  12 , having an occluded segment, generally designated by the reference numeral  14 . Human body  10  is further shown having other arteries, in particular, aorta  16 , right common femoral artery  18 , left common femoral artery  30  and renal arteries  20 . In addition, human body  10  includes a right inguinal ligament  19  and a left inguinal ligament  29 . Human body  10  also includes an epidermis  13  (see e.g. FIG.  6 ). The preferred method disclosed herein describes the implantation of a graft to couple aorta  16  to right common femoral artery  18  thereby bypassing occluded segment  14 . FIG. 2 shows an enlarged view of aorta  16 , right common iliac artery  12 , occluded segment  14 , right common femoral artery  18 , left common femoral artery  30 , renal arteries  20  and right inguinal ligament  19 . In FIGS. 1 and 2, a blood vessel is shown, generally designated by the reference numeral  11 , which includes aorta  16 , right common iliac artery  12 , right common femoral artery  18  and left common femoral artery  30 . Blood vessel  11 , when not occluded, conveys blood from a point C within aorta  16  to a point D within right common femoral artery  18  (see FIGS.  1 - 2 ). However, due to the presence of occluded segment  14 , blood is substantially totally precluded from being conveyed from point C within aorta  16  to point D within right common femoral artery  18  via the direct route of right common iliac artery  12 . While the inventive method will hereinafter be described with regard to a substantially totally occluded segment of a blood vessel of a patient, it will be understood to one skilled in the art that the inventive method is equally effective for bypass of a partially occluded segment of a blood vessel. In addition, the inventive method is also useful for bypass of an aneurysmal segment of a blood vessel. 
     Referring now to FIGS. 3-24, successive steps according to the preferred method of the present invention are depicted of the implantation of a graft prosthesis of the present invention to couple aorta  16  to right common femoral artery  18  thereby bypassing occluded segment  14  of blood vessel  11 . 
     One step of the preferred method of the present invention comprises isolating a region of the area within the blood vessel  11 , located near a site  21  (see FIG. 4) upstream of occluded segment  14 , from fluid communication with the rest of the area within the blood vessel. There also exists a site  31  which is located downstream of occluded segment  14  (see FIG.  4 ). Upstream site  21  is located substantially adjacent the blood vessel  11  and designates a working area where the distal end of medical instruments and various medical devices may be positioned during the process of securing one end of a graft to the blood vessel. Upstream site  21  is located near blood vessel  11  so as to allow such distal end of medical instruments and medical devices to be appropriately manipulated at upstream site  21  to thereby successfully secure the one end of the graft to the blood vessel. Downstream site  31  is located substantially adjacent the blood vessel  11  and also designates a working area where the distal end of medical instruments, physician&#39;s hands and various medical devices may be positioned during the process of securing a second end of the graft to the blood vessel. Downstream site  31  is also located near blood vessel  11  so as to allow such distal end of medical instruments, physician&#39;s hands and medical devices to be appropriately manipulated at downstream site  31  to thereby successfully secure the second end of the graft to the blood vessel. 
     Referring now to FIG. 3, a balloon-tip catheter  22  having a balloon  24  thereon is percutaneously inserted into blood vessel  11  via the right or left axillary artery (not shown). This step may be accomplished using standard catherization techniques. The distal end of catheter  22  is then advanced into aorta  16  until balloon  24  is positioned distal to renal arteries  20  as shown in FIG.  3 . Balloon  24  is then inflated to and maintained at a size such that fluid communication is substantially terminated in aorta  16  between the portion of blood vessel  11  proximal to balloon  24  and the portion of blood vessel  11  distal to balloon  24 . Since conventional balloon-tip catheters may not have a balloon thereon that possess the characteristics necessary to terminate fluid communication in the aorta as described above, modification may be readily made to an existing design of a conventional balloon-tip catheter to achieve the above desired results. One such modification would include providing a balloon on the catheter with is inflatable to an outer diameter which is larger than the inner diameter of the aorta. Another such modification would include providing a coarse textured outer surface to the balloon of the catheter. The above modification would provide increased frictional resistance between the inflated balloon and the sidewall of the blood vessel when force is applied to the balloon in the axial direction thereof. A balloon-tip catheter having a conventional design is available through Medi-tech, Incorporated of Watertown, Mass., as Order No. 17-207 (Description: OBW/40/8/2/100). 
     Referring now to FIG. 4, a balloon-tip catheter  26  having a balloon  28  thereon and an open lumen defined therein is percutaneously inserted into blood vessel  11  via the left common femoral artery  30 . This step may be accomplished using standard catherization techniques. The distal end of the catheter  26  is then advanced into aorta  16  until balloon  28  is positioned proximal to the aortic bifurcation. Balloon  28  is then inflated to and maintained at a size such that fluid communication is substantially terminated in aorta  16  between the portion of blood vessel  11  proximal to balloon  28  and the portion of blood vessel  11  distal to balloon  28 . Since conventional balloon-tip catheters may not have a balloon thereon that possess the characteristics necessary to terminate fluid communication in the aorta as described above, modification similar to that described with respect to catheter  22  may need to be made to catheter  26 . In addition, further modification may need to be made to catheter  26  since a conventional balloon-tip catheter may not have an open central lumen defined therein which possesses a diameter large enough for the advancement therethrough of a compressed stent mounted on a balloon of another balloon-tip catheter as will be required by the preferred method of the present invention (see FIG.  17 ). Such further modification would be to create an open central lumen in catheter  26  that possesses a diameter larger than the outer diameter of the compressed stent which is mounted on the balloon of the balloon-tip catheter as referred to above. Due to the increased size requirements of catheter  26  as alluded to above, a surgical cut-down may need to be performed in order to expose left common femoral artery  30 . Such exposure would facilitate both placement of catheter  26  into blood vessel  11  and repair of such blood vessel following subsequent removal of such catheter therefrom. 
     Temporary occlusion of the blood flow in the inferior mesenteric artery (not shown) by laparoscopic procedures may need to be performed in order to prevent the flow of blood from the inferior mesenteric artery into aorta  16  due to placement of inflated balloons  24  and  28  as discussed above. 
     The region bound by balloon  24  of catheter  22  and balloon  28  of catheter  26  and the sidewall of blood vessel  11  contained therebetween defines a region  40  of the area within blood vessel  11 , located near site  21  upstream of occluded segment  14 , which is substantially isolated from fluid communication with the rest of the area within blood vessel  11 . 
     Alternatively, the step of isolating the region of the area within blood vessel  11 , located near upstream site  21 , from fluid communication with the rest of the area within the blood vessel may be accomplished by laparoscopically placing a first clamp around the blood vessel  11  at the location where balloon  24  of the balloon-tip catheter  22  was described as having been inflated and also laparoscopically placing a second clamp around the blood vessel  11  at the location where balloon  28  of the balloon-tip catheter  26  was described as having been inflated. 
     Another step according to the method of the present invention comprises making an arteriotomy in the sidewall of blood vessel  11 , near upstream site  21 , to create a communicating aperture between upstream isolated region  40  and the outside of blood vessel  11 . 
     Referring now to FIG. 5, right common femoral artery  18  and right inguinal ligament  19  are exposed via a surgical incision  17 . Such exposure is accomplished using standard surgical techniques. 
     Insufflation of the peritoneal cavity is then performed using standard techniques associated with laparoscopy. A laparoscope  37  (see FIG.  6 ), having an open central lumen (i.e. a working channel) defined therein, is then inserted into human body  10  through the opening between right common femoral artery  18  and right inguinal ligament  19 . Laparoscope  37  may additionally include a fiber optic illumination device and a telescope for viewing. A tilt table may be used with the patient (i.e. human body  10 ) positioned thereon in order to maneuver the patient&#39;s abdominal contents away from the laparoscope insertion site and the area near upstream site  21 . Laparoscope  37  is then advanced toward upstream site  21  until its distal end is positioned thereat as shown in FIG.  6 . One or more additional laparoscopes and associated laparoscopic operating instruments may be employed using standard laparoscopic techniques to assist in the above positioning via direct visualization, tissue retraction and tissue dissection. One laparoscope which may be used in carrying out the preferred method of the present invention is available through Karl Storz Endoscopy-America, Incorporated of Culver City, Calif., as Catalog No. 26075A. Modification may be readily made to laparoscope  37 , such as rounding the distal edge thereof, in order to reduce the possibility of tissue trama as a result of advancement of laparoscope  37  within human body  10 . A book which discloses various standard laparoscopic techniques and standard associated laparoscopic operating instruments is entitled “Laparoscopy for Surgeons,” authored by Barry A. Salky, M.D., published by Igaku-Shoin Medical Publishers, Inc. of New York, N.Y., U.S.A. (1990), and the pertinent part of the disclosure of which is herein incorporated by reference. 
     Referring now to FIG. 7, a puncture needle  39  is advanced through the open central lumen of laparoscope  37  until its distal end exits the laparoscope. Thereafter, needle  39  is manipulated to penetrate through the sidewall of blood vessel  11  to the inside thereof, thus creating a puncture in the blood vessel. Needle  39  is then withdrawn and a scissors device  41  is advanced through the open central lumen of laparoscope  37  until its distal end exits the laparoscope (see FIG.  8 ). The scissors device is then manipulated to enlarge the puncture in the sidewall of the blood vessel. Scissors device  41  is then withdrawn from laparoscope  37 . One puncture needle which may be used in carrying out the preferred method of the present invention is available through Karl Storz Endoscopy-America, Incorporated of Culver City, Calif., as Catalog No. 26178R. Additionally, one scissors device which may be used in carrying out the method of the present invention is available through Karl Storz Endoscopy-America, Incorporated of Culver City, Calif., as Catalog No. 26178PS. 
     It should be noted that if upstream isolated region  40  was not substantially isolated from fluid communication with the rest of the area within the blood vessel, the act of making an arteriotomy in the sidewall of blood vessel  11  near upstream site  21  would cause significant blood leakage out of blood vessel  11  and such blood leakage may be fatal to the patient. 
     According to another step of the method of the present invention, a graft prosthesis is positioned so that one end of the graft is located substantially adjacent blood vessel  11  at downstream site  21  and the other end of the graft prosthesis is located substantially adjacent blood vessel  11  at downstream site  31 . The above positioning step includes the step of advancing the graft prosthesis within the human body  10  with a medical instrument. 
     One type of graft prosthesis which may be used is a graft, generally designated by the reference numeral  60  and shown n FIGS. 9A-9E. Graft  60  includes a body portion  61  having a length slightly larger than the distance between upstream site  21  and downstream site  31 . Graft  60  has an outwardly extending flanged end portion  62  as shown in FIGS. 9A,  9 C,  9 D and  9 E. End portion  62  is resiliently maintained outwardly extending by four springs  64 A- 64 D as shown in FIGS.  9 B and  9 E- 9 I. In their relaxed state, springs  64 A- 64 D maintain end portion  62  within a plane P 1  as shown in FIG.  9 A. It should be noted that a number of springs other than four may be used, if desired, to maintain end portion  62  outwardly extending as previously shown and described. Graft  60  further includes a second end portion  63  having a design similar to that of a conventional prosthetic graft as shown in FIG.  9 A. Graft  60  is preferably made of synthetic fibers. By way of example, graft  60  can be made from the material sold under the trademark Dacron by E. I. du Pont de Nemours &amp; Co., Inc. of Wilmington, Del. Body portion  61  and end portion  62  are integrally formed together with springs  64 A- 64 D maintained integrally within the end portion  62  and a portion of the sidewalls of body portion  61  as shown in FIGS. 9B and 9E. Graft  60  maintains its shape as shown in FIGS. 9A-9E absent application of external forces thereto and also graft  60  will revert back to such shape upon termination of such external forces thereto. 
     Graft  60  is positioned within the open central lumen defined in laparoscope  37 . In order to achieve the above, graft  60  is preferably rolled into a substantially cylindrical shape as shown in FIGS. 10A and 10B. End portion  62  of graft  60  is manipulated to lie substantially parallel to body portion  61  of graft  60  while graft  60  is in its rolled configuration as shown in FIG.  10 A. The outer diameter of graft  60 , in its rolled configuration, from point W to point Y is larger than the outer diameter of the rolled graft from point Y to point Z as shown in FIG.  10 A. The above is due to the angular construction of end portion  62  as shown in FIG.  9 A. The outer diameter of the rolled graft from point W to point Y is slightly smaller than the inner diameter of laparoscope  37 . As a result, in its rolled configuration, graft  60  can be positioned within the open central lumen of laparoscope  37 . Moreover, graft  60  can be maintained in its rolled configuration while positioned in the central lumen of laparoscope  37  due to the inner diameter thereof. Graft  60  is then inserted into the proximal end of the central lumen of laparoscope  37  and advanced until its full length is entirely therein. A plunger  82  is insertable into the central lumen of laparoscope  37  as shown in FIGS. 11A and 11B. Plunger  82  has a length sufficient to span the length of laparoscope  37 . Plunger  82  enables an operator to selectively position graft  60  within body  10 . FIGS. 11A and 12 show graft  60  positioned in the distal portion of the central lumen of laparoscope  37  after being advanced by plunger  82 . Laparoscope  37  with graft  60  contained therein is then advanced and manipulated such that the distal end of the laparoscope is advanced through the communicating aperture near upstream site  21  and into isolated region  40 . While the plunger is held stationary, laparoscope  37  is then withdrawn axially over plunger  82  and graft  60  in the direction of arrow  84  as sequentially shown in FIGS. 13-15. This allows graft  60  in its rolled configuration to be delivered out the distal end of laparoscope  37 . FIG. 15 shows end portion  62  of graft  60  positioned within upstream isolated region  40  and end portion  63  of graft  60  positioned at downstream site  31 . Since graft  60  is no longer held in its rolled configuration by the inner diameter of the open central lumen of laparoscope  37 , graft  60  becomes unrolled and reverts to its prerolled configuration as shown in FIG.  16 . Injection of a saline solution into graft  60 , via end portion  63 , may be performed to facilitate the reverting of graft  60  to its prerolled configuration. Alternatively, an additional laparoscope may be used to manipulate graft  60  to its prerolled configuration. Alternatively, a balloon-tip catheter may be advanced into graft  60  via end portion  63  and the graft converted to its prerolled configuration by inflation and deflation of the balloon along various segments of the graft. 
     Also shown in FIG. 16, end portion  62  of graft  60  is positioned within upstream isolated region  40  near upstream site  21  and end portion  63  of graft  60  is positioned at downstream site  31  while body portion  61  of graft  60  is positioned outside of blood vessel  11 . Note that end portion  62  has also reverted back to its prerolled configuration so that such end portion is outwardly extending relative to body portion  61  of graft  60 . 
     Another step according to the preferred method of the present invention includes forming an anastomosis between end portion  62  of graft  60  and blood vessel  11  near upstream site  21 . 
     A balloon-tip catheter  86  having a balloon  88  thereon and further having an expandable stent  90 , in its unexpanded configuration, positioned over balloon  88  is advanced through the open central lumen of catheter  26  until its distal end is located within upstream isolated region  40  near upstream site  21  (see FIG.  17 ). Catheter  86  is further advanced until balloon  88  is positioned substantially adjacent end portion  62  of graft  60  as shown in FIG.  17 . Balloon  88  is then inflated to expand stent  90  to its expanded configuration such that end portion  62  is secured between stent  90  and the sidewall of blood vessel  11  near upstream site  21  as shown in FIG.  18 . Balloon  88  is then deflated and catheter  86  is then removed from body  10  via the central lumen of catheter  26 . FIG. 19A shows body  10  after catheter  86  is removed therefrom. Moreover, FIGS. 20A-20C show end portion  62  of graft  60  being forced into the sidewall of blood vessel  11  by stent  90  (in its expanded configuration) such that graft  60  is secured to blood vessel  11  near upstream site  21  at its end portion  62 . 
     One stent which may be used, with a minor degree of modification, in carrying out the preferred method of the present invention is disclosed in U.S. Pat. No. 4,776,337 issued to Palmaz on Oct. 11, 1988, the pertinent part of the disclosure of which is herein incorporated by reference. Such modification would be to provide stent  90  with an outer diameter (in its fully expanded configuration) that is larger than the inner diameter of blood vessel  11  near upstream site  21 . 
     Note that stent  90  includes a plurality of intersecting bars  71  which span the orifice of graft  60  near end portion  62  as shown in FIG.  20 B. Intersecting bars  71  which span the above orifice do not substantially hinder blood flow through the graft orifice as demonstrated by the technical article entitled “Intravascular Stents to Prevent Occlusion and Restenosis After Transluminal Angioplasty” which was published in the Mar. 19, 1987 edition of the periodical “The New England Journal of Medicine,” the pertinent part of the disclosure of which is herein incorporated by reference. 
     Further modification may be readily made to stent  90  whereby stent  90  would have an opening defined in its sidewall which is of similar dimensions to the orifice of graft  60  near end portion  62 . Such opening would have no intersecting bars traversing thereover. The above modification would allow stent  90  to be positioned within blood vessel  11  near upstream site  21  wherein the above opening would be substantially superimposed over the orifice of graft  60  near end portion  62 . This would allow blood to flow through the connection between blood vessel  11  and graft  60  near upstream site  21  in an unimpeded manner. 
     As a possible additional procedure in order to further ensure the integrity of the anastomosis between end portion  62  of graft  60  and blood vessel  11  near upstream site  21 , a number of sutures  100  may be tied to the sidewall of blood vessel  11  so as to further secure end portion  62  and stent  90  to the sidewall of blood vessel  11  as schematically shown in FIGS. 19B and 19C. This is accomplished by inserting a laparoscope  102  (which is similar to laparoscope  37 ) having an open central lumen into human body  10  until its distal end is near upstream site  21 . Thereafter, a grasper  104  is advanced through the central lumen of laparoscope  102 . The grasper  104  has in its grasp a curved needle  106  having an end of suture  100  attached thereto as shown in FIG.  19 D. By manipulating the distal end of grasper  104 , the needle  106  and the end of suture  100  are passed through the sidewall of blood vessel  11  and end portion  62  of graft  60  and into blood vessel  11 . With continued manipulation, the needle  106  and the end of suture  100  are then brought back out of blood vessel  11 . The suture  100  is then tied by standard laparoscopic techniques. One article that refers to standard laparoscopic techniques for tying sutures is entitled “Laparoscopic Choledocholithotomy”, which was published in Volume 1, Number 2, 1991 edition of the “Journal of Laparoendoscopic Surgery” (Mary Ann Liebert, Inc., Publishers), pages 79-82, and another article that refers to standard laparoscopic techniques for tying sutures is entitled “Improvement in Endoscopic Hernioplasty: Transcutaneous Aquadissection of the Musculofascial Defect and Preperitoneal Endoscopic Patch Repair”, which was published in Volume 1, Number 2, 1991 edition of the “Journal of Laparoendoscopic Surgery” (Mary Ann Liebert, Inc., Publishers), pages 83-90, the pertinent part of both of the above articles of which is herein incorporated by reference. A number of other sutures  100  are then tied to the sidewall of blood vessel  11  and end portion  62  of graft  60  in a manner similar to that hereinbefore described so as to further secure end portion  62  to the sidewall of blood vessel  11  as schematically shown in FIGS. 19B and 19C. One or more additional laparoscopes and associated laparoscopic operating instruments may be employed using standard laparoscopic techniques to assist in the above suturing procedure. Of course, sutures  100  may be sewn in a conventional running fashion so as to secure end portion  62  to the sidewall of blood vessel  11 . Also, end portion  62  may be sutured to the sidewall of blood vessel  11  prior to the placement of stent  90  within blood vessel  11 . 
     Alternatively, the step of forming an anastomosis between end portion  62  of graft  60  and blood vessel  11  near upstream site  21  may be accomplished by suturing alone (i.e. without the use of stent  90 ). In particular, once end portion  62  of graft  60  is positioned within upstream isolated region  40  near upstream site  21  as shown in FIG. 16, end portion  62  is sutured to the sidewall of blood vessel  11  as schematically shown in FIGS. 19E and 19F. Note that in this alternative step, end portion  62  is sutured to an interior portion of blood vessel  11  as schematically shown in FIGS. 19E and 19F. Also note that end portion  62  is sutured to the sidewall of blood vessel  11  so as to be positioned substantially adjacent a portion of the sidewall of blood vessel  11  which substantially surrounds the arteriotomy. This is accomplished by tying a number of sutures  110  to the sidewall of blood vessel  11  and end portion  62  of graft  60  so as to secure end portion  62  to the sidewall of blood vessel  11  as schematically shown in FIGS. 19E and 19F. The sutures  110  shown in FIGS. 19E and 19F are applied in the same manner as the sutures  100  shown in FIGS. 19B,  19 C and  19 D were applied as described above. Of course, sutures  110  may be sewn in a conventional running fashion so as to secure end portion  62  to the sidewall of blood vessel  11 . 
     As a further alternative, the end portion  62  of graft  60  need not be positioned in upstream isolated region  40  but rather end portion  62  may be positioned adjacent the sidewall of blood vessel  11  so that the communicating aperture (i.e. the arteriotomy) in the sidewall of blood vessel  11  near upstream site  21  is aligned with the central passage of graft  60 . At this position, end portion  62  is sutured to the sidewall of blood vessel as schematically shown in FIGS. 19G and 19H. Note that in this further alternative step, end portion  62  is sutured to an exterior portion of blood vessel  11  as schematically shown in FIGS. 19G and 19H. Also note that end portion  62  is sutured to the sidewall of blood vessel  11  so as to be positioned substantially adjacent a portion of the sidewall of blood vessel  11  which substantially surrounds the arteriotomy. This is accomplished by tying a number of sutures  120  to the sidewall of blood vessel  11  and end portion  62  of graft  60  so as to secure end portion  62  to the sidewall of blood vessel  11  as schematically shown in FIGS. 19G and 19H. The sutures  120  shown in FIGS. 19G and 19H are applied in the same manner as the sutures  100  shown in FIGS. 19B,  19 C and  19 D were applied as described above. Of course, sutures  120  may be sewn in a conventional running fashion so as to secure end portion  62  to the sidewall of blood vessel  11 . 
     The remainder of the preferred method of the present invention is performed using standard surgical techniques. A book which discloses various standard surgical techniques is entitled “Color Atlas of Vascular Surgery,” authored by John S. P. Lumley, published by Wolfe Medical Publications Ltd. of Baltimore, Md. (1986), printed by W. S. Cowell, Ltd. of Ipswich, United Kingdom, and the pertinent part of the disclosure of which is herein incorporated by reference. More specifically, another step according to the preferred method of the present invention comprises isolating a region  50  of the area within blood vessel  11 , located near site  31  downstream of occluded segment  14 , from fluid communication with the rest of the area within the blood vessel. Referring now to FIG. 21, a pair of surgical clamps  53  and  55  are positioned on blood vessel  11 , one being placed upstream of isolated region  50  and the other being placed downstream of isolated region  50 . 
     Another step according to the method of the present invention comprises making an arteriotomy in the sidewall of blood vessel  11 , near downstream site  31 , to create a communicating aperture between downstream isolated region  50  and the outside of the blood vessel  11 . End portion  63  of graft  60  is retracted by surgical forceps (not shown) to expose blood vessel  11  near downstream site  31  (see FIG.  22 ). A scalpel puncture is then made in blood vessel  11  near downstream site  31  and thereafter the puncture is extended to the appropriate length with a pair of surgical scissors. FIG. 22 shows the communicating aperture defined in the sidewall of blood vessel  11 , near downstream site  31 . 
     Another step according to the preferred method of the present invention comprises forming an anastomosis between end portion  63  of graft  60  and blood vessel  11  near downstream site  31 . Graft  60  is then cut to an appropriate length and thereafter end portion  63  is cut an appropriate shape for attachment to blood vessel  11 . End portion  63  of graft  60  is then surgically stitched with suture  65  to blood vessel  11  near downstream site  31  as shown in FIG.  23 . 
     Clamps  53  and  55  are then removed from blood vessel  11 , and moreover, balloons  24  and  28  are then deflated and thereafter catheters  22  and  26  are removed from body  10  as shown in FIG.  24 . This allows blood to flow to former upstream isolated region  40 . Once blood flow reaches former upstream isolated region  40 , a flow of blood will enter graft  60  and flow therethrough to former downstream isolated region  50  thereby bypassing occluded segment  14 . Consequently, proper blood flow will now exist in body  10  from point C within aorta  16  to point D within right common femoral artery  18  as a result of performing the above described method of bypass of occluded segment  14 . 
     While the invention has been described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments and methods have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. 
     For instance, it is possible that left common femoral artery  30  and left inguinal ligament  29  could be exposed via a surgical incision similar to that of incision  17  as hereinbefore described. Thereafter, a Y-shaped graft could be utilized instead of graft  60  as hereinbefore disclosed. The Y-shaped graft could be advanced in a rolled configuration through laparoscope  37  and delivered to a position substantially adjacent blood vessel  11  similar in manner to that hereinbefore described. An additional laparoscope could be inserted into human body  10  through the opening defined between left common femoral artery  30  and left inguinal ligament  29  in a manner substantially similar to that hereinbefore described with respect to the insertion of laparoscope  37  into human body  10 . The additional laparoscope could be advanced toward the left limb of the Y-shaped graft and thereafter used to grasp such limb and pull it toward left common femoral artery  30  and subsequently out of the surgical incision near the left common femoral artery. The end portion of the left limb of the Y-shaped graft could be cut to an appropriate length and shape, and thereafter, an anastomosis could be made between such end portion and left common femoral artery  30  similar in manner to that hereinbefore described with regard to right common femoral artery  18  and end portion  63  of graft  60 . 
     Moreover, for example, in an alternative embodiment of the present invention, it is possible that a graft  200  may be utilized which would be similar to graft  60  hereinbefore described, however, both end portions of such graft  200  could be similar in structure to end portion  62  of graft  60  (see FIGS.  29 - 33 ). In other words, each graft end could posses an end portion that is resiliently maintained outwardly extending relative to the body portion of the graft  200 . A catheter  202  could be placed into blood vessel  11  at right femoral artery  18  and advanced toward occluded segment  14  (see FIG.  25 ). Prior to arriving at occluded segment  14 , the distal end of the catheter  202  could be manipulated and guided out of blood vessel  11  through a puncture site  204  laparoscopically created in the blood vessel in a manner similar to that hereinbefore described (see FIG.  26 ). The catheter  202  could then be advanced substantially adjacent blood vessel  11  over and past occluded segment  14  (see FIG.  27 ). One or more additional laparoscopes could assist in the above advancement (see also FIG.  27 ). The distal end of the catheter  202  could then be manipulated and guided to reenter blood vessel  11  at a site upstream of occluded segment  14  through a puncture site  206  laparoscopically created in blood vessel  11  in a manner similar to that hereinbefore described (see FIG.  28 ). The graft  200  having a resiliently outwardly extending end portion at each end thereof could then be advanced in a rolled configuration through the catheter  202  and delivered to a position substantially adjacent blood vessel  11  similar in manner to that hereinbefore described with respect to graft  60  and laparoscope  37  (see FIGS. 29,  30 ,  31 ). The graft  200  could have a predetermined length equal to a length slightly larger than the distance between the puncture site  206  located upstream of occluded segment  14  and the puncture site  204  located downstream of occluded segment  14 . As a result, the distal end portion of the graft  200  could be positioned within blood vessel  11  at a location upstream of occluded segment  14  and the proximal end portion of the graft  200  could be positioned within blood vessel  11  at a location downstream of occluded segment  14  while the body portion of the graft  200  could be positioned substantially adjacent and outside of blood vessel  11  (see FIGS. 29,  30 ,  31 ). Of course, an area within the blood vessel near each end portion of the graft  200  could be isolated from fluid communication with the rest of the area within the blood vessel in a manner substantially similar to that hereinbefore described with respect to upstream isolated region  40 . After being advanced out of the distal end of the catheter  202 , the graft  200  (including each outwardly extending end portion) could revert back to its prerolled configuration as hereinbefore described with respect to graft  60  (see FIG.  32 ). Thereafter, a stent  208  could be placed, in an expanded configuration, adjacent each of the end portions of the graft  200  within blood vessel  11  in order to secure such end portions of the graft  200  to blood vessel  11  as hereinbefore described with respect to stent  90  and end portion  62  of graft  60  (see FIG.  33 ).