Abstract:
Apparatus and methods for endoluminally advancing a tubular prosthesis and a plurality of fasteners to a site in a lumen in a human body and passing the fasteners from an inner surface of the prosthesis through the prosthesis and a wall of the lumen to secure the prosthesis to the wall. Embodiments include simultaneous deployment of fasteners using a graft alone or in conjunction with a stent graft. Another arrangement includes guide lines to guide the end of the fixation deployment device to a specific location of the wall of the prosthesis.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to prosthesis fixation in a passageway in a human body such as an artery. 
       BACKGROUND OF THE INVENTION 
       [0002]    Tubular prostheses such as stents, grafts, and stent-grafts (e.g., stents having an inner and/or outer covering comprising graft material and which may be referred to as covered stents) have been used to treat abnormalities in passageways in the human body. In vascular applications, these devices often are used to replace or bypass occluded, diseased or damaged blood vessels such as stenotic or aneurysmal vessels. For example, it is well known to use stent-grafts, which comprise biocompatible graft material (e.g., Dacron® or expanded polytetrafluoroethylene (ePTFE)) supported by a framework (e.g., one or more stent or stent-like structures), to treat or isolate aneurysms. The framework provides mechanical support and the graft material or liner provides a blood barrier. 
         [0003]    Aneurysms generally involve abnormal widening of a duct or canal such as a blood vessel and generally appear in the form of a sac formed by the abnormal dilation of the duct or vessel wall. The abnormally dilated wall typically is weakened and susceptible to rupture. Aneurysms can occur in blood vessels such as in the abdominal aorta where the aneurysm generally extends below the renal arteries distally to or toward the iliac arteries. 
         [0004]    In treating an aneurysm with a stent-graft, the stent-graft typically is placed so that one end of the stent-graft is situated proximally or upstream of the diseased portion of the vessel and the other end of the stent-graft is situated distally or downstream of the diseased portion of the vessel. In this manner, the stent-graft extends through the aneurysmal sac and beyond the proximal and distal ends thereof to replace or bypass the weakened portion. The graft material typically forms a blood impervious lumen to facilitate endovascular exclusion of the aneurysm. 
         [0005]    Such prostheses can be implanted in an open surgical procedure or with a minimally invasive endovascular approach. Minimally invasive endovascular stent-graft use is preferred by many physicians over traditional open surgery techniques where the diseased vessel is surgically opened and a graft is sutured into position such that it bypasses the aneurysm. The endovascular approach, which has been used to deliver stents, grafts, and stent grafts, generally involves cutting through the skin to access a lumen of the vasculature. Alternatively, lumenar or vascular access may be achieved percutaneously via successive dilation at a less traumatic entry point. Once access is achieved, the stent-graft can be routed through the vasculature to the target site. For example, a stent-graft delivery catheter loaded with a stent-graft can be percutaneously introduced into the vasculature (e.g., into a femoral artery) and the stent-graft delivered endovascularly across the aneurysm where it is deployed. 
         [0006]    When using a balloon expandable stent-graft, balloon catheters generally are used to expand the stent-graft after it is positioned at the target site. When, however, a self-expanding stent-graft is used, the stent-graft generally is radially compressed or folded and placed at the distal end of a sheath or delivery catheter. Upon retraction or removal of the sheath or catheter at the target site, the stent-graft self-expands. 
         [0007]    More specifically, a delivery catheter having coaxial inner and outer tubes arranged for relative axial movement therebetween can be used and loaded with a compressed self-expanding stent-graft. The stent-graft is positioned within the distal end of the outer tube (sheath) and in front of a stop fixed to the inner tube. Once the catheter is positioned for deployment of the stent-graft at the target site, the inner tube is held stationary and the outer tube (sheath) withdrawn so that the stent-graft is gradually exposed and allowed to expand. The inner tube or plunger prevents the stent-graft from moving back as the outer tube or sheath is withdrawn. An exemplary stent-graft delivery system is described in U.S. Patent Application Publication No. 2004/0093063, which published on May 13, 2004 to Wright et al. and is entitled Controlled Deployment Delivery System, the disclosure of which is hereby incorporated herein in its entirety by reference. 
         [0008]    Regarding proximal and distal positions referenced herein, the proximal end of a prosthesis (e.g., stent-graft) is the end closest to the heart (by way of blood flow) whereas the distal end is the end furthest away from the heart during deployment. In contrast, the distal end of a catheter is usually identified as the end that is farthest from the operator, while the proximal end of the catheter is the end nearest the operator. 
         [0009]    Although the endoluminal approach is much less invasive, and usually requires less recovery time and involves less risk of complication as compared to open surgery, among the challenges with this approach are fixation of the prosthesis and prosthesis migration. For example, the outward spring force of a self-expanding stent-graft may not be sufficient to prevent migration. This problem can be exacerbated when the vessel&#39;s fixation zone significantly deviates from being circular. And when there is a short landing zone, for example, between an aortic aneurysm and a proximal branching artery (e.g., one of the renal arteries, or the carotid or brachiocephalic artery), small deviations in sizing or placement may result in migration and or leakage. 
         [0010]    Current endovascular devices incorporate stent-graft over-sizing to generate radial force for fixation and/or sealing and some have included fixation mechanisms comprising radially extending members such as tines, barbs, hooks and the like that engage the vessel wall to reduce the chance of migration. In some abdominal aortic aneurysm applications, a suprarenal stent and hooks are used to anchor the stent-grafts to the aorta. However, abdominal aortic aneurysm stent-grafts typically require an anchor or landing zone of about 10-15 mm to achieve the desired fixation and seal efficacy. In some cases, such an anchoring or landing zone does not exist due to diseased vasculature or challenging anatomy. Other attempts to improve fixation and/or sealing between the prosthesis and an endoluminal wall have included using adhesives and growth factor. There remains a need to develop and/or improve seal and/or fixation approaches for endolumenal or endovascular prostheses placement. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention involves improvements in prosthesis fixation and overcomes disadvantages of prior art. 
         [0012]    In one embodiment according to the invention, a method of securing a tubular prosthesis to an inner wall of a passageway defining a lumen in a human body comprises endoluminally advancing a tubular prosthesis to a site in in a human body; endoluminally advancing a plurality of fasteners to a plurality of sites within the prosthesis; and passing the fasteners from an inner surface of the prosthesis through the prosthesis and a wall of the passageway. In another embodiment according to the invention, a method of securing a tubular prosthesis to an inner wall of a vessel in a human patient comprises endoluminally advancing a tubular prosthesis having an inner surface through a vessel in a human patient to a region of the vessel; endoluminally advancing a plurality of fastener carriers, each carrying at least one fastener, through the vessel to the region; and deploying the fasteners from the carriers and passing the fasteners from the inner surface of the prosthesis through the prosthesis and the vessel to secure the prosthesis to the vessel. 
         [0013]    In another embodiment according to the invention, a prosthesis delivery system comprises a tubular prosthesis having an inner wall; a plurality of guide members extending from the inner wall; and a plurality of fasteners coupled to one or more of the guide members. 
         [0014]    In another embodiment according to the invention, a prosthesis delivery system comprises a catheter having a lumen; a tubular prosthesis having an inner wall surface and being disposed in the catheter lumen; a plurality of guide members extending from the inner wall surface; and a plurality of fasteners coupled to one or more of the guide members. 
         [0015]    In another embodiment according to the invention, endovascular fastener delivery apparatus comprises a catheter having a proximal end and a distal end; at least one fastener delivery tube disposed in the catheter and having a proximal end portion and a distal end portion; at least one self-closing fastener disposed in the fastener delivery tube; and an expander including a radially extendable arm pivotally coupled to said distal end portion of said at least one fastener delivery tube. 
         [0016]    In another embodiment according to the invention, a graft implantation device comprises a catheter having a distal end and a proximal end, the distal end including a tubular graft for implantation, a fastener delivery mechanism for delivering at least two fasteners simultaneously and being disposed within said tubular graft, wherein in a delivery configuration of the catheter, tubular graft, and fastener delivery mechanism have a delivery outside diameter to provide a profile adapted for delivery through the vasculature to a treatment site; wherein in a pre-deployment configuration of the catheter, tubular graft, and fastener delivery mechanism, said tubular graft is held by said fastener delivery mechanism extended radially to a larger diameter than the delivery outside diameter and against a surrounding tissue wall, where upon actuation the fastener delivery mechanism for delivering at least two fasteners simultaneously delivers the at least two fasteners through the tubular graft and into a surrounding tissue, whereby the at least two fasteners fix the tubular graft to the surrounding tissue. 
         [0017]    In another embodiment according to the invention, graft implantation apparatus comprises a catheter having a distal end portion and a proximal end portion, the catheter being sized for delivery through vasculature of a human patient; a plurality of fasteners; a plurality of fastener delivery carriers disposed in the catheter, each fastener delivery carrier having a distal end portion, and each fastener delivery carrier carrying at least one of the fasteners; an expander coupled to the carriers to radially expand the carrier distal end portions; and a tubular graft surrounding at least a portion of the distal end portion of the delivery carriers and being disposed in the distal end portion of the catheter. 
         [0018]    The above is a brief description of some deficiencies in the prior art and advantages of embodiments according to the present invention. Other features, advantages, and embodiments according to the present invention will be apparent to those skilled in the art from the following description and accompanying drawings, wherein, for purposes of illustration only, specific embodiments are set forth in detail. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  diagrammatically illustrates endovascular prosthesis delivery apparatus according to one embodiment of the invention. 
           [0020]      FIG. 2  is an enlarged view of a distal end portion of the apparatus of  FIG. 1 . 
           [0021]      FIG. 3A  diagrammatically illustrates one embodiment of fastener delivery apparatus according to the invention in a pre-deployment state. 
           [0022]      FIG. 3B  diagrammatically illustrates the apparatus of  FIG. 3A  with the distal ends of the fastener tubes positioned at ejection sites and multiple fasteners deployed simultaneously. 
           [0023]      FIG. 3C  is a partial sectional view of  FIG. 3A  taken along line  3 C- 3 C. 
           [0024]      FIG. 3D  is a partial sectional view of  FIG. 3A  taken along line  3 D- 3 D without plunger  120  for purposes of clarity. 
           [0025]      FIG. 3E  is a partial sectional view of  FIG. 3B  taken along line  3 E- 3 E without plunger  120  for purposes of clarity. 
           [0026]      FIG. 3F  is an enlarged view of the section encircled with line  3 F in  FIG. 3B . 
           [0027]      FIGS. 4A and 4B  illustrate one embodiment of a fastener plunger according to the invention where  4 A shows the plunger is in a pre-deployment state and  FIG. 4B  shows the plunger being actuated and a plurality of fasteners being deployed. 
           [0028]      FIG. 4C  diagrammatically illustrates the embodiment of  FIG. 4A  with a tubular graft surrounding a distal end portions of the fastener tubes and disposed in a delivery catheter. 
           [0029]      FIG. 4D  diagrammatically illustrates the tubular graft of  FIG. 4C  after it has been pushed out of the distal end of the catheter, radially expanded and fasteners passed therethrough. 
           [0030]      FIG. 4E  illustrates one embodiment of a fastener according to the invention. 
           [0031]      FIG. 4F  illustrates the fastener of  FIG. 4D  restrained in an open position in a fastener delivery tube. 
           [0032]      FIGS. 5A-5D  diagrammatically illustrate guidance of a fastener delivery tube to a target site on a prosthesis and deployment of a fastener where  FIG. 5A  shows the fastener delivery tube being tracked along a guide member to a target site,  FIG. 5B  shows a the fastener delivery tube at the target site and a fastener being deployed therefrom,  FIG. 5C  shows the fastener fully deployed and the fastener delivery tube removed, and  FIG. 5D  shows the guide member removed from the prosthesis. 
           [0033]      FIG. 6  illustrates another embodiment of guide apparatus according to the invention. 
           [0034]      FIG. 7A  is a partial sectional view of another embodiment of guide apparatus according to the invention. 
           [0035]      FIG. 7B  is end view of the guide apparatus of  FIG. 7A  taken along line  7 B- 7 B. 
           [0036]      FIG. 8  is a partial sectional view of another embodiment of fastener delivery apparatus according to the invention. 
           [0037]      FIGS. 9A-9C  diagrammatically illustrate one method of endoluminally delivering fasteners serially fasteners using the apparatus of  FIG. 8 , where  FIG. 9A  shows the fastener delivery tube of  FIG. 8  positioned in the prosthesis,  FIG. 9B  shows four guide members provided slack and one tightened to move the distal, deployment end of the fastener delivery tube to a target site, and  FIG. 9C  shows a different set of four guide members provided slack and a different guide member tightened to move the distal, deployment end of the fastener delivery tube to another target site. 
           [0038]      FIG. 10A  is a partial sectional view of another embodiment of fastener delivery apparatus according to the invention. 
           [0039]      FIG. 10B  illustrates the longitudinal slot in the fastener tube expander tube of  FIG. 10A . 
           [0040]      FIG. 10C  is an end view of the expander tube of  FIG. 10B . 
           [0041]      FIGS. 11A and 11B  diagrammatically illustrate a pre-deployment state  FIG. 11A  and deployment state  FIG. 11B  using the apparatus of  FIG. 8 . 
           [0042]      FIGS. 12A and 12B  illustrate a method of using any of the apparatus described herein for endoluminally deploying fasteners to secure a prosthesis such as a graft or stent-graft to the proximal landing of an abdominal aortic aneurysm. 
       
    
    
     DETAILED DESCRIPTION 
       [0043]    The following description will be made with reference to the drawings where when referring to the various figures, it should be understood that like numerals or characters indicate like elements. When referring to catheters, delivery devices and loaded fasteners described below the proximal end is the end nearest the operator and the distal end is farthest from the operator. 
         [0044]    Referring to  FIG. 1 , one embodiment of a prosthesis delivery system according to the invention is shown and generally designated with reference numeral  100 . Prosthesis delivery system  100  comprises catheter  102 , which includes catheter sheath  103 , control handle  104 , flexible tapered tip member (or obturator  106 ), which can form a portion of the distal end of the catheter. In the embodiment illustrated in  FIG. 1 , system  100  is equipped with prosthesis  200  and fastener delivery apparatus  300 . 
         [0045]    Handle  104  includes an inlet  108 , through which central guidewire lumen  110  enters the handle and extends to flexible tapered tip member  106 , which has an axial bore for slidably receiving guidewire  112 . Tapered tip member  106  is placed at the distal end of catheter sheath  103  and handle  104  is affixed to the proximal end of catheter sheath  103  in the vicinity of access tube  116 , which is coupled to handle  104  and in fluid communication with catheter sheath  103 , which has a size of about 12 to 28 French. A guidewire  112  can be slidably disposed in guidewire lumen  110  and catheter  102  tracked thereover. When the prosthesis to be delivered is a self-expanding graft or stent-graft (such as stent-graft  200 ), it generally is radially compressed or folded and placed in the distal end portion of the delivery catheter and allowed to expand upon deployment from the catheter at the target site as will be described in detail below. Stent-graft  200  can include a plurality of undulating stent elements to support the tubular graft material as is known in the art. Although the stent framework is shown with a particular configuration in  FIG. 2 , it should be understood that that configuration is merely provided for exemplary purposes and other configurations can be used. Further, the stent framework can be nitinol or any other suitable material. The graft material for any of the prostheses described herein also can be any suitable material such as Dacron® or expanded polytetrafluoroethylene (ePTFE). A graft by itself without a framework may also be used. 
         [0046]    Referring to  FIG. 2 , one delivery catheter system configuration according to the invention is shown in a pre-deployment loaded state. Sheath  103  (outer tube) and guidewire tube  110  (inner tube) are coaxial and arranged for relative axial movement therebetween. The prosthesis (e.g., stent-graft  200 ) is positioned within the distal end of outer tube (sheath)  103  and in front of plunger or stop  120 , which is concentric with and secured to inner guidewire tube  110 . In the illustrative embodiment, pusher member or stop  120  has a wagon wheel shaped configuration with a hub  120   a  having a central access bore, which provides access for guidewire tube  110 , and spokes  121 ,  122 ,  123 ,  124 , and  125 , which radially extend from hub  120   a  to the outer circular portion  120   b  of stop  120  and form spaces therebetween to allow fastener tubes t 1 , t 2 , t 3 , t 4 , and t 5  to slidably pass therethrough as shown in  FIG. 3C . Once the catheter is positioned for deployment of the prosthesis at the desired site, the plunger is held stationary and the outer tube or sheath withdrawn so that the prosthesis, e.g., stent-graft, is gradually exposed and allowed to expand. 
         [0047]    Fastener tubes t 1 , t 2  . . . tn have a length of at least about the length of the delivery catheter, which ranges from about 30-90 cm depending on the application plus a margin of about 20-45 cm to accommodate exiting handle  104  and access tube  116 . Accordingly, the fastener tube length is at least about 50 cm and can be up to about 135 cm. Although one configuration for allowing passage of the fastener tubes is shown, it should be understood that other configurations can be used. In one variation, stop  120  is not included and the distal ends of the fastener tubes provide the mechanism to push stent-graft  200  distally to deploy the prosthesis. In another variation illustrated in  FIGS. 4C and 4D , which will be described in more detail below, a tubular graft  250  without a stent framework surrounds the fastener tubes, which push the tubular graft out from the catheter without stop  120  and radially expand the tubular graft. However, stop  120  can be incorporated in that embodiment according to yet a further variation. 
         [0048]    In the example where prosthesis  200  comprises a stent-graft as shown in the illustrative embodiment depicted in  FIG. 2 , the stent-graft comprises a tubular graft member and a plurality of annular undulated stent elements, such as stent elements  202   a,b,c,d  to provide structural support to the graft as is known in the art. As shown in  FIG. 12B , an undulating bare spring element  212  also can be sutured or otherwise attached to the proximal end of the prosthesis and/or an annular undulating wire  210  having an undulating configuration secured to the proximal end of the prosthesis to provide radial strength as well. The spring has a radially outward bias so that when it is released from a radially restrained state it expands outwardly to secure the proximal portion of the prosthesis to the target passageway wall. Another undulating wire  210  can be attached to the prosthesis distal end as well or in the alternative. More specifically, a support spring  210  can be provided at one or both ends of the prosthesis. The stent and support elements can be positioned on the interior and/or exterior of the graft member and secured thereto by suturing or other conventional means. 
         [0049]    Returning to  FIG. 2 , a radiopaque ring  114  can be provided on the inside of the distal end portion of sheath  103  in overlapping relation to tapered tip  106  to assist with imaging the distal end of sheath  103  using fluoroscopic techniques. Alternatively, radiopaque ring  114  can be provided on the proximal end of the tapered tip. 
         [0050]    A plurality of guide members s 1 , s 2 , s 3 , s 4 , s 5  . . . sn, which can be in the form of a flexible elongated member such as a suture, a wire, thread, or filament, each have one end attached to the inner surface of the graft material of stent-graft  200  or a portion of the stent structure at an attachment point or fastener target site p 1 , p 2 , p 3 , p 4 , p 5  . . . pn. Each guide member extends to a fastener guide tube t 1 , t 2 , t 3 , t 4 , t 5  . . . tn and is slidably coupled to a respective fastener tube so that the guide tube can be tracked thereover. The guide members and fastener tubes extend through catheter  102  between catheter sheath  103  and guidewire lumen  110  out from catheter  102  and into access tube lumen  116 , which extends from the distal end potion of handle  104  and is in fluid communication with the proximal end of catheter sheath  103  which terminates at the distal end portion of handle  104 . The fastener tubes and guide members are coupled to actuator or plunger  310  as will be described in more detail below with reference to  FIGS. 4A and 4B . Although five guide members and corresponding fastener tubes, each loaded with a single fastener, is shown, more or fewer guide members and fastener tubes can be used and each fastener tube can be loaded with more than one fastener. Further, although the attachment points are shown in an annular, equidistantly spaced arrangement, other configurations or arrangements can be used including, but not limited to, spiral arrangements and arrangements where the attachment points are not equidistantly spaced. 
         [0051]    Referring to  FIGS. 3A-3D , diagrammatic views illustrating prosthesis deployment and fixation according to one embodiment of the invention will be described. Once the catheter is positioned for deployment of the prosthesis at the desired site, the inner member or guidewire lumen  110  with stop  120  are held stationary and the outer tube or sheath  103  withdrawn so that tapered tip  106  is displaced from sheath  103  and the stent-graft gradually exposed and allowed to expand. Stop  120  therefore is sized to engage the distal end of the stent-graft as the stent-graft is deployed. The proximal end portions of the sheath  103  and inner tube or guidewire lumen  112  are coupled to and manipulated by handle  104 . Tapered tip  106  optionally can be configured with an annular recess or cavity  106   a  formed in its distal end portion and configured to receive and retain the leading or proximal end portion of the prosthesis in a radially compressed configuration before allowing its expansion during deployment ( FIG. 3F ). Alternatively, any of the stent-graft deployment systems described in U.S. Patent Application Publication No. 2004/0093063, which published on May 13, 2004 to Wright et al. and is entitled Controlled Deployment Delivery System, the disclosure of which is hereby incorporated herein by reference in its entirety, can be incorporated into stent-graft delivery system  100 . 
         [0052]    Referring to  FIG. 3A , the prosthesis is deployed and radially expanded. Fastener tubes f 1 -f 5  are then advanced and guided along guide members s 1 -s 5  to attachment points or fastener target sites p 1 -p 5  as shown in  FIG. 3B . Examples, of fastener tube guide member receiving mechanisms that track over a respective guide member will be described in more detail below in connection with  FIGS. 5A ,  5 B and  7 . Returning to  FIG. 3B , once the distal ends of fastener tubes f 1 -f 5  are positioned at or against target sites p 1 -p 5 , fasteners (see e.g., fasteners f 2  and f 3  in  FIG. 3B ) are deployed from the fastener tubes to secure the prosthesis to the vessel wall. The operator can tactilely determine when the distal ends of the fastener tubes are in contact with the inner wall of the prosthesis. Alternatively, a radiopaque marker can be provided on each guide member at the attachment point and on the distal end of each fastener delivery tube so that the relative positions of the distal end of each fastener delivery tube and corresponding guide member attachment point can be fluoroscopically monitored. In one variation, each fastener tube marker can be placed at a predetermined distance from the distal end of the tube. That information would be processed with traditional means to monitor the relative positions of each guide member attachment site and fastener delivery tube distal end fluoroscopically. 
         [0053]    The distal end portions of each fastener delivery tube also can be bent radially outward as shown, for example, in  FIG. 4A , so that when the fastener tube end is urged against the inner wall of the prosthesis, the fastener is pointed toward the inner wall of the prosthesis to enhance fastener penetration. Typically, the distal end of each fastener tube will be configured or bent so that the fastener can penetrate the prosthesis along a line that is within about  60  degrees of a line that extends radially outward from the longitudinal axis of the guidewire tube toward the designated attachment point for the fastener. 
         [0054]    The fasteners can be self-closing fasteners having a loop shaped memory set closed configuration. They can be made from nitinol wire and placed in the desired shape (e.g., that shown in  FIG. 4E ) and heated for about 5-15 minutes in a hot salt bath or sand having a temperature of about 480-515° C. They can then be air cooled or placed in an oil bath or water quenched depending on the desired properties. In one alternative, the fasteners can be surgical grade stainless steel that is deformed to assume such a preshaped configuration. In a further embodiment, the fasteners can be polymeric material with a preshaped loop configuration to which they return when released from the fastener tube. 
         [0055]    Returning to  FIGS. 3A and 3B , optional expandable balloon of conventional construction can be used to provide radial support for the distal end portions of the fastener tubes to stabilize the tubes and/or minimize or eliminate fastener tube movement away from the target sites during fastener deployment. In the illustrative example, the expandable balloon is secured to a portion of guidewire tube  110  and spaced from tapered tip member  106  such that when the guidewire tube and tapered tip are advanced to fully deploy the stent-graft as shown in  FIG. 3A , the uninflated balloon is radially aligned with the fastener target sites. An end view of stop  120  is shown in  FIG. 3C , which is a view taken along line  3 C- 3 C in  FIG. 3A . After the fastener tubes are advanced so that their distal ends are close to or abut the inner wall of prosthesis  200 , the balloon is inflated so that it expands and urges the fastener tubes against the inner wall of the prosthesis to stabilize the fastener tubes in a desired position as shown in  FIG. 3B . Once the tubes are stabilized, the fasteners are deployed. The balloon can be polyurethane and fluidly coupled to an external pressure source through a lumen formed in the wall of the guidewire tube as would be apparent to one of skill in the art. 
         [0056]      FIG. 3D  diagrammatically shows a sectional view taken along line  3 D- 3 D in  FIG. 3A  where the fastener tubes f 1 -f 5  are ready to be tracked along guide s 1 -s 5  to target sites or points p 1 -p 5 .  FIG. 3E  diagrammatically illustrates fastener tubes t 1 -t 5  tracked to the target sites p 1 -p 5  and positioned against the inner wall of prosthesis  200 , which, in its expanded state, forms contact with the inner wall of vessel V. A plurality of fasteners f 1 -f 5  is shown deployed to fix the prosthesis to the vessel and enhance seal formation therebetween. Typically, at least about a  15 mm landing zone is required to secure a stent-graft or graft to a vessel. However, the fastener procedure described herein and illustrated throughout the figures, can facilitate the requisite fixation and sealing when the landing zone is only about 5 mm in length. The region of a vessel between the aneurysm and the nearest branch vessel is referred to as the landing zone. One such landing zone is depicted in  FIGS. 5A-D  and designated with reference character LZ. 
         [0057]    Referring to the embodiment illustrated in  FIGS. 4A and 4B , ejector apparatus to eject fasteners f 1 -f 5  from fastener tubes f 1 -f 5  is shown integrated into fastener delivery apparatus  300 . In the illustrative embodiment, the ejector apparatus comprises a plurality of pusher rods r 1 -r 5  each of which is slidably disposed in a fastener tube and configured to push a fastener out from the tube. The proximal end portions of the pusher rods are fixedly secured to plunger  316  (e.g., to the distal portion of the plunger), which can include radial extending and laterally spaced grip members or wings  316   a  and  316   b . Plunger  316  also includes a central bore  318  though which guide members s 1 -s 5  pass. 
         [0058]    Plunger  316  is slidably disposed in tubular fastener tube holding member  312 , which is slidably disposed in access tube  116  and which can include radially extending and laterally spaced grip members or wings  312   a  and  312   b . The proximal ends of fastener tubes f 1 -f 5  are fixedly secured in through holes that extend through plug or disk member  320 , which is secured to the inner wall of tubular fastener tube holding member  312 . In this manner, tube holding member  312  can be advanced or retracted to advance or retract tubular members t 1 -t 5 . Plug or disk member  320  can include a through bore  322  through which guide members s 1 -s 5  can be passed. When plunger  316  is actuated, the pusher rods r 1 -r 5  are simultaneously advanced in fastener tubes s 1 -s 5  to eject all of the fasteners (e.g., fasteners f 1 -f 5 ) from the fastener tubes. In this manner all of the fasteners can be ejected in a single thrust of plunger  316 . Further, the pusher member and fastener tube lengths can be selected so that all of the fasteners are simultaneously ejected. 
         [0059]    Referring to  FIGS. 4C and 4D  the ejector apparatus of  FIG. 4A  is shown in one variation where tubular graft  250 , which does not include a stent framework, surrounds the fastener tubes. In  FIG. 4C , graft  250  and distal portions of the fastener tubes are shown disposed within the distal end portion of delivery catheter tube  103 . Graft  250  is arranged about the fastener tubes so that the fastener tubes carry graft  250  with them as they are pushed out from catheter tube (sheath)  103 . In one embodiment, tubular graft extends over the curved distal ends of the fastener tubes and that relationship with the compaction of the graft about the fastener tubes allows the tubes to carry graft  250  when they are advanced. When graft  250  is outside catheter sheath  103 , the balloon can be expanded to radially expand the fastener tubes and tubular graft  250  as shown in FIG,  4 D, where the fasteners also are shown deployed. In use, the graft would be positioned at the desired endoluminal site before radial expansion and fastener deployment. In one variation, stop  120  can be incorporated as described above to assist in pushing graft  250  out from catheter sheath  103 . 
         [0060]    Referring to  FIG. 4E , one fastener embodiment is shown and designated with reference numeral  400 . Fastener  400  includes a sharp piercing end  402  and an enlarged end portion  404  that the distal end of a respective pusher rod pushes through a fastener tube. The fastener can be provided with a memory shaped closed loop configuration as described above.  FIG. 4F  shows one fastener  400  restrained in an open configuration in fastener tube t 1 . Such a fastener can be loaded in all of the delivery tubes in a similar manner. 
         [0061]    Referring to  FIGS. 5A-5D , a coupling system for slidably coupling the fastener delivery tubes to guide members is diagrammatically shown. Although a plurality of fastener tubes are shown in  FIG. 4A , a single tube is provided in this example for simplification. The coupling system generally comprises one or more tubes or sleeves that extend from or are attached to a respective fastener tube and are configured to allow a guide member to slidably pass therethrough. In this example, fastener delivery tube t 1  has one tubular member  500   a  extending from or attached to its outer surface at its distal end and another tubular member  500   b  extending from or attached to an intermediate portion of its outer surface. Fastener delivery tube t 1  is sized to slidably receive one of the guide members such as guide member s 1  so that fastener delivery tube t 1  can be tracked along the guide member ( FIG. 5A ) to a target site where the guide member is attached to the inner wall of prosthesis  200  as shown in  FIG. 5B . The other fastener delivery tubes are similarly sized and provided with similar coupling systems. Although not shown, it should be understood that one or more additional tubular members can be provided along tubular member t 1 . After fastener tube t 1  is positioned at the target site, pusher rod r 1  is advanced to deploy fastener f 1  ( FIG. 5B ). Fastener tube t 1  is then retracted ( FIG. 5C ) and the guide member cut and removed from graft  200  ( FIG. 5D ) using traditional endoscopic techniques. 
         [0062]    Referring to  FIG. 6 , another guide member arrangement is shown where the guide member “s′” is looped through prosthesis  200 ′, which can be, for example, a graft or stent-graft. The guide member enters and exits the inner wall of the prosthesis. Both ends of the guide member extend through bore  322  and exit plunger  316  (see  FIGS. 4A &amp; 4B ). In this manner, one end of the guide member can be pulled to remove the guide member from the vessel after the prosthesis has been secured in place. 
         [0063]    In the embodiment illustrated in  FIG. 7A , another mechanism for slidably coupling a fastener tube to a guide member is shown. In this embodiment, fastener delivery tube “t′” includes a first lumen  510  that is sized for passage of a fastener and pusher rod thererthough and a second lumen  512  that is sized so that a guide member can slidably pass therethrough. A guide member such as guide member s 1  passes through lumen  512  and disk  320  and extends out from plunger  316 . 
         [0064]    Referring to  FIG. 8 , an alternative fastener delivery apparatus including a single fastener delivery tube “tx” loaded with a plurality of serially aligned fasteners is shown. Although five fasteners, fasteners f 1 -f 5 , are shown serially loaded in the fastener tube lumen in front of the distal end of pusher rod “rx,” fastener delivery tube “tx” can be loaded with more or fewer fasteners. A plurality of guide members, e.g., guide members s 1 -s 5 , are slidably coupled to fastener delivery tube “tx” through one or more couplings such as sleeve or tubular members  600   a  and  600   b , which extend from or are attached to the fastener tube in the same manner as described above regarding sleeves  500   a  and  500   b  with sleeve  600   a  being at the distal end of fastener delivery tube “tx”. Fastener tube “tx,” pusher rod “rx,” and the guide members extend back through catheter sheath  103  and exit the system through access tube  116  where the operator can manipulate these elements to position and deploy the fasteners at the target sites. The fastener delivery tube “tx” can be coupled to disk  320  and the guide member passed through bore  322  of disk  320  (see  FIGS. 4A &amp; 4B ) or tube holding member  312  eliminated and the fastener delivery tube and guide member simply passed through plunger  316 . In a further arrangement, plunger  316  also can be eliminated. The fasteners also can vary from the fasteners shown in  FIG. 8 . For example, the rounded end portions can be flat, dimpled, or otherwise configured to enhance their cooperation with a trailing fastener that pushes it forward. 
         [0065]    One method of using fastener delivery tube “tx” is diagrammatically shown in  FIGS. 9A-C . The proximal end of fastener tube “tx” is manipulated (e.g., pushed) to position its distal end in the vicinity of target sites p 1 -p 5 . All of the guide members are provided slack ( FIG. 9A ) and then the slack is taken up in one guide member (guide member s 1  in  FIG. 9B ) and fastener tube “tx” advanced. As the fastener tube is advanced, it will track along the taut guide member so that its distal end can be positioned close to or in contact with the inner wall of prosthesis  200 . Pusher rod “rx” can then be pushed to deploy a single fastener. After the fastener is fully deployed to secure a portion of the prosthesis to a vessel wall, guide member s 1  is given slack, the slack in guide member s 2  taken up, and fastener delivery tube “tx” advanced. In this manner, the distal end of fastener tube tx is positioned close or in contact with a second target site ( FIG. 9C ). The fastener tube can be slightly retracted before tightened guide member s 2  and then advanced after the slack in guide member s 2  is taken up. The apparatus also allows the operator to move sequentially from p 1  to p 2  to p 3  to p 4  to p 5  or in any other sequence. In this manner, the distal end of the fastener tube can be repositioned at the various target sites and a fastener at each site. 
         [0066]    Referring to  FIGS. 10A-C  and  11 A- 11 B another fastener delivery apparatus for incorporation in prosthesis delivery system  100  is shown and generally designated with reference numeral  700 . Fastener delivery apparatus  700  includes a tubular member  702  that tracks over guidewire tube  110  and one or more fastener tubes  706   a, b . . . n , which are coupled to tubular member  702 . Referring to  FIGS. 10B and 10C , tubular member  702  can include a slot  712  extending its entire length with the slot having a width slightly greater than the diameter of guidewire lumen  110  to allow tube  702  to branch away from guidewire lumen  110  and enter access tube  116  with fastener delivery tubes  706   a ,  706   b  . . .  706   n.    
         [0067]    In the embodiment illustrated in  FIG. 10A-C , a plurality of struts  704   a,b . . . n  extend from or are attached to the distal end portion of tubular member  702  and form an expandable member. Although six struts are shown equidistantly spaced in  FIGS. 10B and 10C , other arrangements and numbers of struts can be used. Typically two to eight struts are used. Struts  704   a,b . . . n  are spaced from one another about the circumference of the distal end portion of tubular member  702  and extend from tube  702  through flexible portions or hinges  705   a,b . . . n  so that they can pivot or move to the position shown in  FIG. 11B  where they radially extend from tube  702 . The distal end portions of struts  704   a,b . . . n  are pivotally coupled to respective fastener tubes  706   a,b . . . n  through flexible portions or hinges  710   a,b . . . n  so that the struts and fastener tube pairs can pivot relative to one another (see  FIGS. 11A  &amp; B). In one example, foregoing hinges can comprise a flexible connection between the members being coupled. In another example, the portion of material at the juncture of tube  702  and a strut can have a thinner wall thickness than that of the tube and strut to provide a hinge. Each of the fastener tubes can be provided with a fastener and pusher rod as shown in  FIG. 4A  to facilitate fastener deployment at the target site. When using the fastener deployment apparatus of  FIG. 4A , a central bore would be provided in disk  320  in place of bore  322  to slidably receive tubular member  702 . Tubular member  702  would extend through bore  320  and out from plunger  316 . 
         [0068]    In operation, tubular prosthesis  720  is deployed in vessel V and the distal ends of fastener tubes  706   a, b . . . n  are positioned slightly beyond the target fixation sites as shown in  FIG. 11A . The proximal end of the fastener tubes are held in a fixed position and the proximal end of tubular member  702  retracted as shown in  FIG. 11B . As tubular member  702  is retracted, struts  704   a, b . . . n  are forced radially outward. As struts  704   a, b . . . n  move radially outward, distal end portions  708   a ,  708   b  . . .  708   n  of fastener tubes  706   a, b . . . n,  which extend beyond catheter (sheath)  103 , move radially outward and close to or contact the inner wall of prosthesis  720 . The pusher rods, which are connected to plunger  316  (see  FIGS. 4A  &amp; B) are then advanced to deploy, for example, fasteners  400   a, b . . . n,  and fixedly secure prosthesis  720  to vessel V. Struts  704   a, b . . . n  are sufficiently rigid so as not to flex when the fasteners are deployed. This can be accomplished through material selection or heat treating as would be apparent to one of ordinary skill in the art. For example, the struts can be formed from a different and more rigid material than tube  702  and hingedly coupled to the distal end of tube  702 . The struts also can include reinforcement members. 
         [0069]    In one variation, prosthesis  200  can replace prosthesis  720 , and each fastener tube provided with one or more guide member couplings such as coupling  500   a, b . . . n  so that the distal ends of the tracking members can be guided to predetermined target sites. Once the distal ends of the fastener tubes are in the desired position, tube  702  can be held stationary relative to the other components so that struts  704   a, b . . . n  support and stabilize the distal ends of the fastener delivery tubes during fastener deployment. 
         [0070]    Referring to  FIGS. 12A-B , a method of securing prosthesis  200  to bypass an abdominal aortic aneurysm is shown using fastener delivery apparatus  300 . In this example, the prosthesis and apparatus are delivered percutaneously to a femoral artery and advanced to the vicinity of the abdominal aortic aneurysm to be bypassed. It should be understood, however, that this example, but merely is provided for illustrative purposes. Accordingly, other prosthesis configurations can be used to treat different vascular disorders. 
         [0071]    The proximal portion of bifurcated stent-graft  200  is positioned below branch vessel BV 2  and along the proximal landing between aneurysm A and branch vessel BV 2 . In this example, vessel V is the aorta and two branch vessels BV 1  and BV 2 , which correspond to the renal arteries, are shown. The prosthesis is deployed and fixedly secured using fastener delivery apparatus  300  as described above ( FIG. 12B ). After the stent-graft is secured with the fasteners, all catheters are withdrawn. Contralateral leg portion  208 , which can include a tubular graft member and annular wire springs or stents  202   i - m,  is then secured to the graft member short leg portion  206  as is known in the art. The fully deployed stent-graft is shown in  FIG. 12B  includes ipsilateral leg  204  and contralateral stump  206  to which contralateral leg  208  is coupled using conventional techniques. The combined prosthesis includes stent elements  202   a - m.    
         [0072]    Any feature described in any one embodiment described herein can be combined with any other feature of any of the other embodiments. 
         [0073]    Variations and modifications of the devices and methods disclosed herein will be readily apparent to persons skilled in the art.