Patent Publication Number: US-2007123972-A1

Title: Modular stent graft assembly and use thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This is a continuation of application Ser. No. 10/104,672, filed Mar. 22, 2002, which claims priority of provisional application Ser. No. 60/279,329, filed Mar. 28, 2001, both of which are incorporated by reference. 
    
    
     TECHNICAL FIELD  
      The present invention relates to medical devices and more particularly to modular endovascular stent grafts.  
     BACKGROUND OF THE INVENTION  
      In recent years treatment of aneurysms has been performed prior to aneurysm rupture and has included the use of stent grafts that are implanted within the vascular system with minimally invasive surgical procedures and that include one or more stents affixed to graft material. The stent grafts are secured at a treatment site by endovascular insertion utilizing introducers and catheters, whereafter they are enlarged radially and remain in place by self-attachment to the vessel wall. In particular, stent grafts are known for use in treating descending thoracic and abdominal aortic aneurysms where the stent graft at one end defines a single lumen for placement within the aorta and at the other end is bifurcated to define two lumens, for extending into the branch arteries.  
      One example of such a stent graft is disclosed in PCT Publication No. WO 98/53761 in which the stent graft includes a sleeve or tube of biocompatible graft material such as Dacron™ polyester fabric (trademark of E. I. DuPont de Nemours and Co.) or polytetrafluoroethylene defining a lumen, and further includes several stents secured therealong, with the stent graft spanning the aneurysm extending along the aorta proximally from the two iliac arteries; the reference also discloses the manner of deploying the stent graft in the patient utilizing an introducer assembly. The graft material-covered portion of the single-lumen proximal end of the stent graft bears against the wall of the aorta above the aneurysm to seal the aneurysm at a location that is spaced distally of the entrances to the renal arteries. Thin wire struts of a proximal stent extension traverse the renal artery entrances without occluding them, since no graft material is utilized along the proximal stent while securing the stent graft in position within the aorta when the stent self-expands. An extension is affixed to one of the legs of the stent graft to extend along a respective iliac artery and, optionally, extensions may be affixed to both legs. Another known stent graft is the Zenith AAA™ stent graft sold by William A. Cook Australia Pty. Ltd., Brisbane, Queensland, Australia.  
      Because of life threatening time constraints, such conventional stent grafts are not practical to be utilized with ruptured aneurysms, which presently must be treated, if at all, by open surgery.  
      Despite the multitude of advances in surgical management and intensive care, the devastating physiological effects of emergency aortic surgery for either ruptured abdominal aortic aneurysms (RAAA) or symptomatic abdominal aortic aneurysms (SAAA), carry an unacceptably high morbidity and mortality rate. Most patients who suffer from RAAA and SAAA are typically unaware of their aneurysmal disease prior to the development of symptoms of actual or impending rupture. The acuity of an RAAA precludes complex radiographic evaluation, does not allow for adequate preoperative planning, and is compounded by the relative unavailability of endovascular stent grafts. Additionally, because of the rapid blood loss from the patient, any substantial surgical delay cannot be tolerated. Another complication stems from the statistical fact that most patients who suffer RAAA or SAAA are elderly and have factors that preclude repair of the rupture by open surgery, with the result that patient mortality from RAAA is very high. Approximately 15,000 deaths per year occur in the United States from ruptured abdominal aortic aneurysms.  
      Conventional surgical repair of ruptured and symptomatic aneurysms is itself associated with significant complications. Cardiopulmonary complications as a result of a prolonged abdominal operation, significant blood loss and aortic cross clamping, multiple blood transfusions, and hypothermia are most frequently encountered. Mortality of ruptured aneurysms is currently estimated to be between 50% and 75%.  
      It is thus desired to provide medical devices enabling emergency endovascular treatment of RAAA and SAAA. It is further desired to provide such devices in a manner not requiring, on site at a surgical treatment center, a large inventory of different size devices while still enabling immediate treatment of a large range of aneurysm sizes, nor in a manner requiring preoperative study of the treatment site taking a substantial length of time in order to optimize the selection of an appropriate device. It is yet further desired to provide a medical device that is quickly deliverable and effectively deployable at the treatment site.  
     SUMMARY OF THE INVENTION  
      The foregoing problems are solved and a technical advance is achieved in an illustrative modular stent graft assembly of the present invention. The stent graft assembly is to be a life-saving device first, and a permanent implant second. Each stent graft assembly comprises at least two components or sections, thus allowing for quick deployment; extensions can be added if necessary. The cranial or aortic section has a diameter corresponding to the normal or undiseased diameter of the aorta of the patient, and the caudal or iliac section has a diameter corresponding to the normal or undiseased diameter of the common iliac artery. The diameter of the aortic section of the assembly is sized to be at least 10 percent larger than the aortic artery for leakproof engagement therewith, while the diameter of the iliac section of the assembly is sized to be at least about 10 percent larger than the ipsilateral iliac artery, both thus assuring no deficiency in diameter that could otherwise result in leakage around the assembly or migration of the assembly following placement. Preferably, each section has an assembly interconnection portion with a constant diameter of, for example, 12 mm for at least a predetermined length of, for example about 56 mm to facilitate interconnection in a wide range of overall assembly lengths. The overall length of the implanted stent graft assembly is adjustable intraoperatively by varying the amount of overlap at the interconnection. An iliac occluder can also be utilized for occluding the contralateral iliac artery, with a conventional crossover connection to be made between the ipsilateral and contralateral iliac arteries, if possible.  
      A preferred inventory of components or devices includes a set of aortic assembly sections of a common length (exclusive of the attachment stent length) with proximal end portions having one of a standard set (four) of proximal diameters (34, 30, 26 and 22 mm); and iliac sections of a common length with distal end portions having one of a standard set (four) of different distal diameters (24, 20, 16 and 12 mm). In addition, occluders having one of a standard set (four) of different diameters (24, 20, 16 and 14 mm) could be included in the inventory. Such inventory provides for the largest coverage of the different patient anatomy with the fewest number of components or devices; however, the lengths of the assembled devices can be varied to accommodate different patient anatomy.  
      This invention is designed to perform a compromise operation which can be performed with a maximum of safety and yet produce a satisfactory and safe result. No time is spent on accurately measuring the dimensions of a patient&#39;s aorta, and no time is spent on manipulating a second graft down a second iliac artery and to thereby connect a second iliac leg thereto.  
      The method of use includes inserting the aortic section of the assembly into the aortic artery and engaging the proximal end with portion thereof the aorta just below the renals with the distal end portion extending distally into the aorta. The iliac section is inserted into the ipsilateral artery with engagement thereagainst at the distal end portion thereof. The proximal end portion of the iliac section interconnects with the distal end portion of the aortic assembly section to provide an overlapping interconnection that can be adjusted to accommodate the patient&#39;s anatomy. An occluder is then implanted in the contralateral iliac to isolate the ruptured aneurysm.  
      When an elderly patient is suffering from a rupture or dissection of an aortic aneurysm, all of the blood is immediately bypassed to one of the iliac arteries such as the ipsilateral iliac artery and the patient&#39;s life is saved. The provision of the contrailiac occluder and the bypass graft between the contrailiac artery and the ipsilateral iliac artery is a relatively unimportant detail and not too relevant to the life of the patient. Furthermore, the latter detail can be attended to after the ruptured vessel is isolated. The above operation may seem to be somewhat crude, but it is designed to protect the lives of elderly and very ill patients who would otherwise die. Each of the above steps has been performed separately for various reasons, but this is the first time that they have all been performed in sequence in a single permanent operation. One would not be expected to perform such an operation in a single procedure since it seems impractical and clumsy and yet it works and saves lives. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
      An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which:  
       FIG. 1  diagrammatically illustrates the stent graft assembly of the present invention deployed within a ruptured aneurysm, and an occluder in a selected iliac artery;  
       FIG. 2  is an exploded side view of the stent graft assembly of the present invention having an aortic section and an iliac section;  
       FIG. 3  shows an occluder plug to be used with the present invention;  
       FIG. 4  shows a first embodiment of a set of stent graft assembly components having an aortic section graft and two iliac section grafts;  
       FIG. 5  illustrates a second embodiment of aortic section grafts;  
       FIG. 6  shows a third embodiment of a set of graft assembly components having an aortic section style and three iliac graft styles;  
       FIG. 7  is a Dimension Table containing dimension information on the stent graft sections of FIGS.  4  to  6 ;  
      FIGS.  8  to  11  show the delivery systems for the three components, with  FIG. 9  showing the trigger wire controls included in the aortic section system of  FIG. 8 ;  
       FIGS. 12, 12A  and  12 B show enlargements of the trigger wire containment arrangement for the attachment stent (proximal end) and for the distal end portion of the aortic graft;  
       FIGS. 13 and 14  are enlargements of the proximal end of the aortic graft showing the trigger wire locking mechanism for the attachment stent; and  
       FIG. 15  depicts a complete set of delivery systems having four standard size aortic section grafts, four standard size iliac section grafts, and four standard size occluders. 
    
    
     DETAILED DESCRIPTION  
      The modular stent graft assembly of the present invention includes one or more devices and is intended for use in the abdominal aorta for symptomatic or ruptured aneurysm repair. Referring first to FIGS.  1  to  3 , the stent graft assembly  10  is modular and comprises an aortic section  12 , an iliac section  14 , and a contralateral iliac occluder  80 .  
      Aortic section  12  and iliac section  14  are interconnected and overlap each other within the aneurysm  90  upon deployment, while occluder  80  is deployed separately within the contralateral iliac artery  98 . Aortic section  12  is affixed at the aneurysm neck  92  below the renal arteries  94 , with iliac section  14  extending into ipsilateral iliac artery  96 . A conventional femoro-femoral bypass or cross-over procedure using a bypass graft (not shown) will reconnect the ipsilateral iliac artery to the contralateral iliac artery distal to the occluder  80 , to convey blood from the side receiving the entire aortic blood flow through the stent graft assembly, to the other limb, in a manner disclosed in U.S. Pat. No. 5,693,084. The delivery systems (see FIGS.  8  to  11 ) for each component of the stent graft assembly are each comprised of a sheath into which the stent graft (or plug) is compressed, and a tapered tip for a smooth transition from wireguide-to-sheath diameters. The delivery system for the aortic section uses trigger wire release mechanisms to lock the endovascular graft onto the delivery system until the graft is precisely positioned axially and then released by the physician to be deployed at the deployment site. The delivery system is compatible with an 0.035 in (0.889 mm) wire guide.  
      The aortic section  12  includes a proximal end portion  26  and a distal end portion  28 , with a tapered transition portion  30  that interconnects the distal end portion having a constant diameter of 12 mm, and the proximal end portion  26  having a selected larger diameter. An attachment stent  32  is secured to the proximal end portion, with the stent&#39;s distal end portion  34  along the inside surface of the graft material  36 , while the remaining attachment portion  38  extending proximally from the graft material and having barbs  40  for example for becoming affixed to the vessel walls.  
      Aortic section  12  also has several additional stents  42 , 44 , 46  with stent  42  adjacent to the attachment stent being disposed within the graft material, and stents  44 , 46  being secured about the outer surface of the graft material  36  along the length thereof distally of the attachment stent  32  and stent  42 .  
      The proximal end portion  26  preferably is denoted by a plurality of radiopaque markers (not shown) such as gold marker members for facilitating fluoroscopic visualization of the proximal end of the graft material, for placement distally of the renal arteries.  
      The contralateral iliac artery occluder in  FIGS. 1 and 3 , may be a conventional occluder  80 , such as the Zenith AAA™ Iliac Plug sold by William A. Cook Australia Pty. Ltd., Brisbane, Queensland, Australia, which comprises a tubular length of graft material  82  of 20 mm with a single stent  84  sutured therewithin, having a diameter of between about 14 mm and 24 mm; one end  86  of the tubular structure traverses and closes the lumen therethrough with graft material  82  for sealing. A procedure for delivering such a contralateral iliac occluder and for performing a femoro-femoral bypass or cross-over procedure using a bypass graft is disclosed in U.S. Pat. No. 5,693,084.  
      Preferably, the present invention includes a set of graft components limited in number but selected to accommodate most rupture sites, and includes four aortic sections  12  each differing in the size of their proximal diameters, and includes four iliac section  14  each differing in the size of their distal diameters, while the diameters of the distal ends of the four aortic sections  12  and the diameters of the proximal ends of the four iliac sections  14  is constant among the eight bodies. Preferably, the proximal diameter of the aortic section  12  is standardized for each of four aortic sections to have one of four dimensions: 34 mm, 30 mm, 26 mm and 22 mm. The distal end portion  52  of the iliac section  14  is standardized for each of four iliac sections to have one of four standardized diameters: 24, 20, 16 and 12 mm.  
      Several designs or embodiments of aortic sections are shown in FIGS.  4  to  6 , and several designs or embodiments of iliac sections are also shown in  FIGS. 4 and 6 . Dimension information for the different standard sizes for the designs of the tubular grafts in FIGS.  4  to  6  is contained in the Dimension Table,  FIG. 7 , for easy reference, and includes proximal end and distal end diameters; proximal, distal and transition portion lengths; and interstent gap spacing for both the aortic and iliac tubular grafts. The lengths of the stents and their geometries and spacing can be varied to increase or decrease the flexibility of the system; also, two stents could optionally be utilized in the proximal end portion of the aortic section tubular graft.  
      With respect to  FIG. 4 , one aortic section tubular graft  12  is shown, and two designs of iliac section tubular grafts  14   a ,  14   b  are shown. The diameter D P  of the proximal end of aortic tubular graft  12  is one of four standardized diameters: 34 mm, 30 mm, 26 mm and 22 mm. The diameter D D  of the distal end is 12 mm. The total length is preferably about 127 mm, with the proximal end portion length L P  being 26 mm; the transition portion length L T  being 33 mm; and with the distal end portion length L D  being 68 mm. Transition portion  30  is shown to include two transition stents  44 ,  62  with substantial spacing therebetween. Regarding interstent gap spacings, G 1  between the attachment stent and the first stent  42  is 2 mm; G 2  between first stent  42  and first transition stent  44  is 5 mm; G 3  between the first and second transition stents  44 ,  62  is 5 mm; G 4  between second transition stent  62  and the adjacent distal stent  46  is 3 mm; while gaps G 5  between the several distal stents  46  are 3 mm.  
      The iliac section tubular graft  14   a  has a proximal end portion  50  with a diameter d P  of 12 mm, and a distal end portion  52  of a selected diameter d D  of also 12 mm. Also, preferably, iliac tubular graft  14   a  has a total length of 94 mm, with the proximal end portion length l P  being about 73 mm in length, the distal end portion length l D  being about 17 mm in length, and there is no tapered transition portion extending between the proximal and distal portions since the proximal and distal diameters are the same. As to iliac section tubular graft  14   b , also having a total length of 94 mm, the diameter d P  is 12 mm while the distal end portion has a selected diameter d D  of 16, 20 or 24 mm. Proximal end portion length l P  is 73 mm; transition portion  54  has a length l T  of 4 mm; and distal end portion length l T  is 17 mm. The proximal and distal end portions may have respectively a proximal-most and a distal-most stent  56 ,  58  affixed internally of the graft material, and three axially short stents  60  therebetween affixed externally of the graft material  36 . Gap g 1  between distal stent  58  and the adjacent stent  60  is 4 mm, while gaps g 2  between the remaining stents  56 ,  60  are 3 mm.  
      Referring now to  FIG. 5 , the proximal end portion  26  of the aortic section tubular graft  12  has a length L P  of about 35 mm with one stent  42  therewithin, the distal end portion  28  has a length L D  of about 70 mm with four axially short stents  46  therearound, and the tapered transition portion  30  therebetween has a length L T  of about 17 mm with one stent  44  therearound. Transition portion  44  is seen to have only one stent  44  therearound and is shorter than the transition portion  44  of the embodiment of  FIG. 4 . Regarding interstent gap spacings, G 1  between the attachment stent and the first stent  42  is 2 mm; G 2  between first stent  42  and transition stent  44  is 14 mm; G 4  between transition stent  44  and the adjacent distal stent  46  is 5 mm; while gaps G 5  between the several distal stents  46  are 3 mm. The iliac section tubular grafts for use therewith may be identical in design and dimension to those shown in  FIG. 4 .  
      In  FIG. 6  is shown one aortic section tubular graft  12 , and three designs of iliac section tubular grafts  14   a ,  14   b ,  14   c . The total length of the aortic tubular graft  12  and each of the iliac tubular grafts is about equal. The diameter D P  of the proximal end of aortic tubular graft  12  is, again, one of four standardized diameters: 34 mm, 30 mm, 26 mm and 22 mm. The diameter D D  of the distal end is 12 mm. The total length is preferably about 108 mm, with the proximal end portion length L P  being 28 mm; the transition portion length L T  being 20 mm; and with the distal end portion length L D  being 60 mm. Regarding interstent gap spacings, G 1  between the attachment stent and the first stent  42  is 2 mm; G 2  between first stent  42  and transition stent  44  is 3 mm; G 4  between transition stent  44  and the adjacent distal stent  46  is 3 mm; while gaps G 5  between the several distal stents  46  are 1 mm.  
      As with the iliac section tubular grafts of  FIG. 4 , the proximal and distal end portions of iliac tubular grafts  14   a ,  14   b ,  14   c  of  FIG. 6  have respectively a proximal-most and a distal-most stent  56 ,  58  affixed internally of the graft material, and four axially short stents  60  therebetween affixed externally of the graft material  36 . The iliac tubular graft  14   a  has a proximal end portion  50  with a diameter d P  of 12 mm, and a distal end portion  52  of a selected diameter d D  of also 12 mm. Also, preferably, iliac tubular graft  14   a  has a total length of 110 mm, and there is no tapered transition portion extending between the proximal and distal portions since the diameters are the same. As to iliac tubular graft  14   b , also having a total length of 110 mm, the diameter d P  is 12 mm while the distal end portion has a selected diameter d D  of 16 or 20 mm. Proximal end portion  50  length l P  is 56 mm; transition portion  54  has a length l T  of 34 mm; and distal end portion  52  length l D  is 20 mm. Gap g 1  between distal stent  58  and the adjacent stent  60  is 3 mm, and gaps g 2  between the remaining stents  56 ,  60  are also 3 mm. Iliac section tubular graft  14   b  differs from graft  14   c  in that graft  14   c  has a distal diameter of 24 mm. The transition portion need not be precisely symmetrically tapered, as can be seen.  
      Regarding the differences between the embodiments of  FIGS. 4, 5  and  6 , the transition portion of the aortic section graft  12  of  FIG. 4  is elongated with two stents therearound spaced substantially from each other, in comparison with the transition portions of the aortic grafts of  FIGS. 5 and 6 . The greater spacing provides more flexibility while utilizing two stents minimizes any tendency of the graft to buckle and close slightly, when finally deployed in the aneurysm and also thereafter as the aneurysm shrinks over time, and minimizes the chance of endoleaks. The longer, more gradual taper of the transition portion of  FIG. 4  reduces somewhat forces from the blood flow through the deployed stent graft assembly tending to pull the stent graft assembly distally, and thus reduces any tendency of the graft assembly to migrate. Turbulent blood flow is also further reduced with the longer transition portion because of the longer transition portion length. The aortic section graft  12  of  FIG. 4  has a longer total length than the lengths of aortic grafts  12  of  FIGS. 5 and 6 , while the iliac section grafts are correspondingly shorter with one less stent therealong, and with a shorter transition portion having no stent therearound.  
      The graft to be selected is based on the findings from preoperative radiologic studies, including computerized tomography (CT), magnetic resonance imaging (MRI), or conventional angiography. The outside diameter of the graft is intended to be at least 10 percent larger than the proximal implantation site. The attachment site for distal implantation is also oversized at least about 10 percent. The assumption is being made that a small amount of graft redundancy or vessel stretching would be inconsequential, whereas a small deficiency in the diameter of the graft could result in either endoleakage or migration. Determination of the proximal diameter of the aortic graft depends primarily on a measurement of the aneurysm neck  92  from preoperative or intraoperative imaging. If the neck of the aneurysm  90  appears to have an elliptical section on trans-axial images, the true profile is assumed to be circular and the true diameter is the diameter of the narrowest part of the ellipse. If CT scanning is unavailable, intraoperative intravascular ultrasound (IVUS) may be used to determine the diameter. In determining the graft length, the intended implantation sites must first be identified. The proximal implantation site is generally just distal to the lowest renal artery  94  so that the graft material  36  does not cover the renal arteries  94 , with attachment made by the proximal bare stent portion  38  extending over and past the renal arteries. The distal implantation site is in the ipsilateral iliac artery  96  (typically proximal to the takeoff of the hypogastric artery). Both sections of the stent graft assembly have fixed lengths. The overall length of the assembly is adjusted intraoperatively by varying the amount of overlap at the interconnection of the two sections.  
      Referring to FIGS.  8  to  11 , the delivery systems for the aortic section, iliac section and contralateral iliac occluder will now be described. The delivery system  100  for aortic sections  12  is illustrated in  FIGS. 8 and 9 , having a delivery sheath  102 , a top cap  104  and tapered dilator  106  at proximal end  108 , and a fitting  110  at distal end  112  of the delivery system. Top cap  104  is affixed to the distal end of dilator  106 , which is affixed at the proximal end of a small diameter inner cannula  120  that extends completely through the delivery system to the distal end. Fitting  110  is affixed to sheath  102 , and joined to the side of fitting  110  is injection system  114 , for  
      saturating the stent graft with anticoagulant heparin prior to deployment, and optionally for the injection of contrast medium thereafter.  
      At the distal end of fitting  110  is a check-flow valve  116  through which extends pusher  118 . Distally of pusher  118  is seen handle  122  of cannula  120 , and trigger wire control systems  124 .  
      Stylet  126  extends through cannula  120 , through pusher  118  and introducer sheath  102  and top cap  104  to a proximal tip  128  that protrudes from the proximal end of the tapered dilator  106 ; stylet  126  is of protective value during shipping and handling but is removed prior to use in the medical procedure. Tabs  130  are provided at the distal end of short sheath  132 , for peeling away the sheath prior to the medical procedure; sheath  132  protects the patency of the introducer lumen at the check-flow valve during shipping and handling, and extends only into fitting  110 . For protection of the distal end components during handling, a protective tube  134  is secured therearound, and it also is removed prior to the procedure.  
      Trigger wire control systems  124  are shown in greater detail in  FIG. 9 . Control systems  124  for the two trigger wires  136 ,  138  of the delivery system  100  each include a safety lock  140  that is removed laterally, and a release ring  142  that is moved distally (away from the patient) parallel to the cannula  120  and pulls the respective trigger wire out of the assembly. The trigger wire  136  for securing the attachment stent  32  of the aortic graft  12  against any axial movement until released, is first to be removed prior to being able to actuate the controls for trigger wire  138  that secures the distal end portion  28  of the aortic graft against any axial movement until released. Also, the release ring  142  for the distal end portion may be a different color than that for the attachment stent, to clearly indicate to the physician which trigger wire the particular control system actuates. The release rings  142  have axial slots  144  therealong to permit lateral removal from about the inner cannula  120 . Pin vise  146  tightens upon and releases inner cannula  120  so that top cap  104  and tip  106  can be advanced to deploy and be withdrawn for docking and system withdrawal.  
      Delivery system  200  for extension leg  14  is shown in  FIG. 10 , and is similar to system  100 , including a delivery sheath  202 , tapered dilator  204  at proximal end  206 , and a fitting  208  at distal end  210  of the delivery system. Joined to the side of fitting  208  is the heparin injection system  212 , and inner cannula  214  with handle  216  therefor extends from distal end  210 . Tabs  220  are provided at the distal end of short sheath  222  that extends only into fitting  208 , for peeling away the sheath prior to use, and stylet  224  is also removed prior to use. Also in  FIG. 10  is seen check-flow valve  226 , pusher  228 , pusher fitting  230  and pin vise  232 , with a protective tube  234  thereover similar to protective tube  134  of  FIG. 7 .  
      Delivery system  250  for a conventional contralateral iliac occluder  80  is shown in  FIG. 11 , and includes two assemblies. Introducer  252  includes a tapered dilator  254  and a delivery sheath  256  that is adapted for delivery over a guide wire along the contralateral iliac artery. Second assembly  258  includes a short sheath  260  containing occluder  80 , a fitting  262  with a heparin injection system  264  extending from the side thereof, a three-disk check-flow valve  266 , and a pusher  268  for pushing the contralateral iliac occluder  80  from the distal end of the sheath  260 .  
      Proximal end  270  of sheath  260  is inserted into the proximal end  272  of introducer  252  once the introducer is positioned and the guide wire and dilator removed. Pusher  268  then is utilized to move the occluder  80  into the delivery sheath  256  and therealong to the deployment site adjacent to the bifurcation with the aorta. Alternatively, an occluder may be utilized that is deliverable over a guide wire, and that transversely closes completely upon withdrawal of the guide wire after complete deployment of the occluder.  
      In FIGS.  12  to  14 , the trigger wire  136  is shown in detail in relationship to attachment stent  32  of aortic graft  12 .  FIG. 13  illustrates attachment stent  32  before top cap  104  has been placed over the exposed struts  148 , during which a suture holds the strut ends  48  gathered near the inner cannula  120 ; the suture is removed once the top cap is in place. Trigger wire  136  extends from its control section  124  along small diameter cannula  120  of the delivery system  100  within pusher  118 , and includes a locking section  150  that extends outwardly through an aperture of proximal pusher body  152  and forwardly through aortic graft  12  and then outwardly thereof near proximal end  26  thereof, then forwardly and into a small aperture of the top cap and through a loop at the joined proximal ends  48  of a pair of struts  148  and then further into the dilator, held therein by friction fit by the inner cannula threaded into the dilator. Release portion  150  holds the proximal ends  48  of the exposed struts of the attachment stent within the top cap, fixed against axial movement with respect to the top cap and dilator. Top cap  104  surrounds all the exposed struts  148  of attachment stent  32  when the aortic section graft  12  is delivered to the site of the ruptured aneurysm, until it is accurately positioned at the aneurysm neck.  
      First sheath  102  is then pulled distally with respect to aortic graft  12  by manual movement of fitting  110  while the struts of the attachment stent are held within and still restrained within top cap  104 , as seen in  FIGS. 12 and 14 , after which trigger wire  136  is pulled from the top cap and withdrawn completely from the catheter, thus releasing the loop of the attachment stent struts. With the aortic graft held against axial movement relative to pusher  118  by trigger wire  138 , the dilator/topcap/cannula assembly is pushed forwardly (proximally) by pushing forwardly on cannula handle  122  to release the attachment stent  32 , whereupon the ends  38  of struts  148  self-expand radially outwardly to engage the vessel wall, as shown in  FIG. 1 , and barbs  40  seat into the vessel wall to thereafter secure the aortic graft  12  in its desired position. Such a trigger wire system is disclosed in WO 98/53761. Optionally, a molding balloon may be used to inflate within self-expanded attachment stent  32  to assuredly press the struts against the vessel wall and seat the barbs.  
      Similarly, as shown in  FIG. 12A , the second trigger wire  138  secures the distal end portion  28  of aortic graft  12  against any axial movement as the top cap  104  is being urged forwardly from attachment stent  32  which would otherwise tend to pull the attachment stent and the aortic graft due to friction. Trigger wire  138  includes release portion  154  that first extends outwardly from proximal pusher body  152  and along groove  156 , then inwardly through the graft material of the distal end portion  28  and through a stent end  48  loop and into an opening in the proximal pusher body  152 , and then forwardly along inner cannula  120  where it is held in a force fit thereagainst by the proximal tip of pusher  118 . Then, upon actuation of its control system  124 , trigger wire  138  is pulled from the delivery system which releases the distal end portion  28  of the aortic graft  12  which then fully self-expands within the aneurysm toward the vessel wall.  
      Proximal pusher body  152  is then pushed proximally through now-deployed aortic graft  12  to abut against the distal end of the top cap  104 ; the abutment portion of proximal pusher body  152  is selected to have an outer diameter the same as the distal end of the top cap. The configuration of proximal pusher body  152  is shown in  FIG. 12 . Upon pulling the dilator/topcap/cannula assembly distally, and in turn upon moving proximal pusher body  152  distally, tapered surfaces of the distal end (not shown) of the proximal pusher body gently engage and deflect radially outwardly any portions of the stents of the aortic graft to prevent any stubbing or snagging that otherwise would occur by engagement of the top cap distal end were it to be exposed when pulled distally through the now-deployed aortic graft  12 . Proximal pusher body  152  similarly has tapered surfaces  158  at its proximal end  160  that gently engage and deflect outwardly any stent portions when it is pushed proximally through the aortic graft to abut top cap  104 . Delivery system  100  is then removed from the patient.  
      Then, delivery system  200  is introduced into the patient through sheath  102  and ipsilateral iliac artery  96  and into distal end portion  28  of aortic section  12  that is now deployed in the aneurysm, until the proximal end portion  50  of iliac section  14  is within distal end portion  28 . Proximal end portion  50  of iliac section  14  is then released in a fashion similar to aortic section  12  (although no trigger wires or top cap are involved), and self-expands to press against the inner surface of distal end portion  28  in telescoping region  64  and establish a friction fit therewithin, after which distal end  52  of iliac section  14  is then released to self-expand against the vessel wall of ipsilateral iliac artery  96 , completing the assembly and deployment of stent graft  10  in the aorta of the patient, with proximal end portion  26  of aortic section sealing against the vessel wall in the aneurysm neck  92 , and the distal end portion  52  of iliac section  14  sealing against the vessel wall of the ipsilateral iliac artery.  
      Delivery system  250  is then delivered through the contralateral iliac artery to deliver the contralateral iliac occluder  80  to its proper location distally of the aortic/iliac bifurcation. Occluder  80  is then pushed as sheath  256  is withdrawn, so that occluder  80  emerges from the sheath proximal end and self-expands to press and seal against the vessel wall of the contralateral iliac artery, whereafter the delivery system  250  is fully withdrawn from the patient. The femoro-femoral bypass graft is then secured to connect the ipsilateral iliac artery to the contralateral iliac artery distally of the occluder.  
      After deployment of the stent graft  10  and the occluder  80  and securing of the bypass graft, blood will flow into proximal end portion  26  of aortic section tubular graft  12 , and through the remainder of stent graft assembly  10  into the ipsilateral iliac artery, completely bypassing the ruptured aneurysm, and a portion of the blood flow will pass through the bypass graft to the contralateral iliac artery.  
      The deployment systems are fabricated with a single lumen vinyl radiopaque tubing of 18 to 20 Fr (6.0 to 6.67 mm) aortic section or a 14 to 16 Fr (4.66 to 5.33 mm) iliac section, an 18 gauge cannula (stainless steel), 0.013 and 0.015 in (0.330 and 0.381 mm) trigger wires (stainless steel), nylon radiopaque top cap and radiopaque PTFE sheath material. The graft consists of uncrimped tubular fabric such as Twillweave™ Micrel™ polyester fabric (product of Vascutek) with stents such as of stainless steel strategically sewn into place with suture such as braided polyester and monofilament polypropylene suture. The stents are preferably well-known self-expanding Gianturco Z-stents, however, balloon expandable stents an also be used. The stent at the proximal end of the aortic section preferably contains barbs that are placed at a 3 mm stagger. A number of gold marker bands are preferably positioned around the top of the main graft body to facilitate fluoroscopic visualization.  
      The stent graft aortic section and iliac section delivery system is designed to first be inserted into the femoral artery following surgical exposure of the artery. Prior to the insertion of the delivery system, the ruptured aneurysm is properly diagnosed and controlled if necessary with an occlusion balloon, and access to the artery is achieved with an arterial needle, “J” wire, and appropriate angiographic equipment. The “J” wire is exchanged for a stiff guide wire. The aortic section is then inserted and deployed as described in the instructions for use. Guide wire access is kept through the aortic section. The iliac section is then placed in a similar fashion to the aortic section and is positioned so that the distal portion will be deployed at the proper implantation site and there is at least one, preferably two, full stent overlap between the iliac section and the aortic section. Access is gained in a similar way to the contralateral femoral artery with a large sheath, and the occluder is then loaded and deployed through the large sheath. The attachment of the stent graft at the implantation site can be maximized by inflating a molding balloon at each site to fully expand the attachment stent to press against the arterial wall and seat the barbs of the stent into the wall.  
      A complete inventory or set of delivery systems  300  for treatment of a ruptured aneurysm is depicted in  FIG. 15 . The set  300  includes delivery systems  100 A,  100 B,  100 C,  100 D each containing an aortic section graft having a different one of the standardized proximal diameters; delivery systems  200 A,  200 B,  200 C,  200 D each containing an iliac section graft having a different one of the standardized distal diameters; and delivery systems  250 A,  250 B,  250 C,  250 D each containing an occluder having a different one of the standard diameters for the iliac vessel. The set thus allows the practitioner to quickly select an aortic section graft size and an iliac section graft size and to begin treatment immediately. The set  300  thus provides a minimized inventory of delivery systems capable of treating a great majority of ruptured aneurysms with only relatively rudimentary aneurysm size estimation procedures. Immediate replacement of the delivery systems actually used in a particular treatment, can then be made to complete the set for the next emergency ruptured aneurysm event.  
      No particular departure is necessary from the usual perioperative management of patients undergoing aneurysm repair. The perioperative evaluation and intraoperative monitoring should be performed as though the patient was undergoing conventional surgical repair. Post-operative management should be dictated by clinical circumstances, and is likely to differ somewhat from the usual management of patients following aneurysm repair, because the patients should tend to experience fewer physiologic difficulties.