Abstract:
The present invention embodies delivery systems and methods of packing an initial endovascular graft components for delivery that achieve a smaller delivery profile and reduce redundancy. Delivery systems and methods for packing the initial endovascular graft components for delivery facilitate a reduced delivery profile while allowing reliable positioning of the components before deployment.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to methods for delivering and deploying modular sections of an endovascular stent/graft for assembly thereof within the vasculature of a patient and specifically to a system for accomplishing the same. 
     It is well established that various fluid conducting body or corporeal lumens, such as veins and arteries, may deteriorate or suffer trauma so that repair is necessary. For example, various types of aneurysms or other deteriorative diseases may effect the ability of the lumen to conduct fluids and, in turn, may be life threatening. In some cases, the damage to the lumen is repairable only with the use of prosthesis such as an artificial vessel or graft. 
     For repair of vital lumens such as the aorta, surgical repair is significantly life threatening or subject to significant morbidity. Surgical techniques known in the art involve major surgery in which a graft resembling the natural vessel is spliced into the diseased or obstructed section of the natural vessel. Known procedures include surgically removing the damaged or diseased portion of the vessel and inserting an artificial or donor graft portion inserted and stitched to the ends of the vessel which were created by the removal of the diseased portion. More recently, devices have been developed for treating diseased vasculature through intraluminal repair. Rather than removing the diseased portion of the vasculature, the art has taught bypassing the diseased portion with a prosthesis and implanting the prosthesis within the vasculature. An intra arterial prosthesis of this type has two components: a flexible conduit, the graft, and the expandable framework, the stent (or stents). Such a prosthesis is called an endovascular graft. 
     It has been found that many abdominal aortic aneurysms extend to the aortic bifurcation. Accordingly, a majority of cases of endovascular aneurysm repair employ a graft having a bifurcated shape with a trunk portion and two limbs, each limb extending into separate branches of vasculature. Currently available bifurcated endovascular grafts fall into two categories. One category of grafts are those in which a preformed graft is inserted whole into the arterial system and manipulated into position about the area to be treated. This is a unibody graft. The other category of endovascular grafts are those in which a graft is assembled in-situ from two or more endovascular graft components. This latter endovascular graft is referred to as a modular endovascular graft. Because a modular endovascular graft facilitates greater versatility of matching individual components to the dimensions of the patient&#39;s anatomy, the art has taught the use of modular endovascular grafts in order to minimize difficulties encountered with insertion of the devices into vasculature and sizing to the patient&#39;s vasculature. 
     Although the use of modular endovascular grafts minimize some of the difficulties, there are still drawbacks associated with the current methods. Drawbacks with current methods can be categorized in three ways; drawbacks associated with delivery and deployment of the individual endovascular graft components, drawbacks associated with the main body portion, and drawbacks associated with securing the limb portions to the main body portion. 
     The drawbacks of current methods of delivery and deployment of endovascular graft components include redundant components for delivery, delivery of both a graft and its securing stent as a single entity, and at least minor surgery in order to gain access to the vasculature of the patient. Current methods for delivering the individual components of a modular endovascular graft to the treatment site require the use of a separate delivery catheter for each component and exchange of the delivery catheters through an introducer sheath after each component has been deployed. There are a number of disadvantages to this method. Since each delivery catheter has to be smaller than the introducer sheath, this limits the design of the implant, makes packing the implant into the delivery system more difficult, and increases the force required to deploy the implant. The use of multiple delivery catheters increases production costs and decreases reliability due to the multiplicity of catheter parts required. The process of removing one delivery system and replacing it with another may require coordination between two operators to ensure that guidewire access is maintained, a longer guidewire, additional procedure time, a large amount of physical space, and additional trauma to the insertion and delivery sites. 
     Furthermore, the known methods for delivering grafts to the required location within a patient&#39;s vascular system also require that an attachment system be delivered simultaneously with the graft, axially overlapping the graft and located either on the interior or the exterior of the graft&#39;s lumen, so that upon deployment of the graft the attachment system is expanded to attach the graft to the vascular wall. The attachment system is typically connected to the graft before implantation in the patient by means such as stitching. As a consequence, the outer diameter of the delivery capsule or sheath containing the compressed graft is increased by the presence of the compressed attachment system. Complications may be encountered in maneuvering the compressed graft and its delivery system around the bends and branches of the patient&#39;s vascular system. It will be appreciated that the greater the outer dimension of the capsule containing the compressed graft to be delivered, the more inflexible it will be, making delivery to the final destination more difficult and perhaps even impossible in some patients. 
     Moreover, in the majority of cases, the patient must be subject to surgery in which the appropriate vessel is surgically exposed and opened by incision to allow entry of the graft. Significantly, it is this surgical procedure on the vessel which gives rise to the most serious complications such as infection, patient discomfort, and necrosis of the vessel itself. However, if the outside dimension of the delivery capsule were sufficiently small, it might be possible, depending on the size and condition of the patient, to insert the capsule into the patient&#39;s vessel by applying sufficient force to the skin and artery of the patient with a sharpened end of the graft&#39;s delivery capsule, similar to the commonly known method of inserting a needle directly into the vein or artery of a patient. 
     The drawbacks of current embodiments of the main body component of a modular endovascular graft include a relatively large delivery profile due to the aforementioned graft and supporting stent as a single entity as well as additional stents within the separate branches of a bifurcated main body portion, difficulty in catheterizing the connection site of the first endovascular graft component prior to introduction of the second endovascular graft component, and a lack of adequate healthy tissue near the aneurysm for anchoring the graft to the aortic wall. Although the prior art has taught that the larger delivery profile of a combined graft and supporting stent can be minimized by providing separate support stents for the trunk and limb support branches of the main body component rather than a single support stent for the entire main graft component, separate support stents for the limb support branches are conventionally located at the same axial level. This results in a larger delivery profile since the support stents, when collapsed for delivery, lie on top of each other. 
     Furthermore, because of the restricted geometry of the vasculature and the small diameter of the limb supporting branch of the main body component, it can be difficult to insert one element of a modular endovascular graft into another. The instrumentation required to insert catheters and deploy the limb components of a modular endovascular graft inside the main graft limb support sections can dislodge mural thrombus in the AAA. The dislodged mural thrombus is carried in the blood flow through the femoral arteries to small distal arteries causing blockage and tissue necrosis. 
     Moreover, a lack of healthy tissue near the aneurysm being treated provides difficulty with adequately anchoring the main body portion of a modular endovascular graft. If the aneurysm is too close to the renal arteries there may be a lack of healthy tissue to adequately anchor the neck of the main graft portion without interfering with blood flow in the renal arteries. If the aneurysm extends too close to the bifurcation of the vasculature, there may be a lack of healthy tissue to adequately anchor the limb support branches of the main body component. Anchoring the limb support branches of the main body component in the iliac arteries requires a larger main body component and additional effort and delivery hardware. Allowing the limb support branches of the main body component to float freely in the aneurysm presents other difficulties with deploying the limb components of the modular endovascular graft within the main body component. 
     With regard to the method of delivery and deployment of endovascular graft components, there therefore exists a need for a endovascular graft delivery system that limits the amount of redundancy of delivery components required, can be easily operated by a single technician without decreased reliability or additional risk to the patient, facilitates a reduced outside dimension of the capsule or sheath containing a compressed graft component to be delivered to the patient&#39;s vascular system, and minimizes the need for surgery in order to gain entry to the patient&#39;s vasculature. 
     The devices and methods of the present invention addresses these and other needs. 
     SUMMARY OF THE INVENTION 
     Briefly and in general terms, the present invention is embodied in delivery systems and methods which minimize redundancy and profile and which are relatively easy to operate or perform. 
     An introducer sheath sufficiently long to reach the treatment site is provided. The introducer sheath acts to deliver an initial implant as well as a conduit to maneuver a plurality of subsequent implants into position and to restrain the implants until they are deployed into the body. The components of the system are deployed using the introducer sheath as the deployment catheter, obviating the need to have a second, larger sheath in place to exchange separate catheters. 
     A loading capsule which consists of a restraining sheath and a pusher assembly is also provided. The loading capsule is not a full catheter, but simply a short restraining sheath covering the implant. The loading capsule can be sized so that it is the approximately the same inner diameter as the introducer sheath. The loading capsule may have a fitting or lock that is designed to mate to a similar fitting on the introducer sheath. Once the loading capsule and introducer sheath have been mated together, a pusher assembly is used to transfer the collapsed implant from the loading capsule to the introducer sheath. The pusher is then used to push the implant down the length of the introducer into position. Once the physician is ready to deploy the implant, the pusher assembly is held in a fixed position and the introducer sheath is retracted, allowing the self-expanding implant to deploy. 
     The pusher assembly can be a tube similar to the inner lumen of a standard delivery system. Using one hand, the operator pushes the implant down the length of the introducer sheath. Following deployment, the operator removes the pusher assembly. Once the pusher assembly has been removed, more implant modules can be loaded and deployed using the same procedure. 
     Throughout this specification, the term “proximal” shall mean “nearest to the heart,” and the term “distal” shall mean “furthest from the heart.” Additionally, the term “ipsi-lateral” shall mean the limb of a bifurcated graft which is deployed using the same path through the vasculature that was used to deploy the main body component, and the term “contra-lateral” shall mean the limb of a bifurcated graft which is deployed using a second path through the vasculature which is catheterized after the main body component has been deployed. Furthermore, the term “inferior” shall mean “nearest the technician”, and the term “superior” shall mean “farthest from the technician.” Briefly and in general terms, the present invention is embodied in an endovascular graft composed of individual components delivered individually and assembled in-vivo and methods for delivering, deploying and assembling the same that eliminate the drawbacks described above. 
     In one aspect, the invention includes a delivery system and method for its use that facilitates delivery of the components of an endovascular graft with a reduced delivery profile over a tortuous route through vasculature, but requires little redundancy of delivery devices and can be operated by a single technician with minimal or no surgery required in order to gain entry to the patient&#39;s vasculature. Two embodiments of the delivery system and method are contemplated. Both embodiments are composed of devices that facilitate delivery and deployment of the main body and limb components described herein. 
     In a preferred embodiment, the delivery system has an introducer sheath assembly, loading capsule, self-expanding endovascular graft and a pusher assembly. The introducer sheath is sufficiently long to reach the treatment site. This introducer sheath tracks over a guidewire and maneuver the endovascular graft components into position and restrain the components in their constrained state until they are deployed. With the introducer sheath as the deployment catheter, the need for a second, larger sheath to exchange separate catheters is obviated. The loading capsule is a short, hollow restraining sheath covering the endovascular graft component and holding it in a constrained state. The loading capsule is mated with the introducer sheath and the pusher assembly is used to transfer the constrained endovascular graft component into the introducer sheath and to push the endovascular graft component to the intended position for deployment. The pusher assembly is placed over the guidewire after the loading capsule is mated to the introducer sheath. That is, the guidewire is configured to run through the introducer sheath and when the loading capsule is attached and locked to the introducer sheath, the guidewire is positioned to pass therethrough. A notch in the pusher assembly allows the guidewire to exit the pusher assembly without having to traverse its entire length. The operator can grasp the guidewire with one hand while using the other hand to push the constrained endovascular graft component into and through the introducer sheath. The self-expanding endovascular graft component is deployed by holding the pusher assembly in a fixed position while the introducer sheath is retracted. The pusher assembly is then removed by retracting it with one hand while holding the guidewire steady with the other hand. Multiple endovascular graft components can be delivered and deployed using the same procedure. 
     In an alternate embodiment, the delivery system has a single catheter which is used to deliver and deploy multiple self-expanding endovascular graft components. The catheter has an outer sleeve that can be retracted, thereby exposing an inner shaft that holds a self-expanding endovascular graft component. Each endovascular graft component deploys in succession as the catheter is maneuvered into position and the outer sleeve is retracted. The inner shaft is composed of a hypotube or lumen shaft with mechanical stops at the proximal and distal ends, component separators along the surface, and a rubber-like tip and inner endovascular graft support. The proximal end of the outer sleeve may be tapered with a outer ring of increased thickness and the outer surface of the proximal end of the inner shaft may contain grooves to facilitate retraction and capture of a partially-deployed stent prior to full deployment. 
     Other features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view, depicting an introducer sheath loaded with a medical device; 
         FIG. 1A  is a partial cross-sectional view, depicting a first step in delivering a medical device within vasculature; 
         FIG. 1B  is a partial cross-sectional view, depicting a second step in delivering a medical device within vasculature; 
         FIG. 1C  is a partial cross-sectional view, depicting a third step in delivering a medical device within vasculature; 
         FIG. 1D  is a partial cross-sectional view, depicting a fourth step in delivering a medical device within vasculature; 
         FIG. 1E  is a perspective view, depicting a delivery system of the present invention having a loading capsule, pusher assembly, and introducer sheath; 
         FIG. 2  is a cross-sectional view of an alternate embodiment of the loading capsule depicted in  FIG. 1  having a soft plastic tube and short metal sleeve attached to a hard plastic body; 
         FIG. 3A  is a partial perspective view of a loading capsule and an introducer sheath of the present invention having a valve assembly at the inferior end; 
         FIG. 3B  is view of the introducer sheath valve assembly knob depicted in  FIG. 3A  from the inferior end; 
         FIG. 3C  is view of the introducer sheath valve assembly knob depicted in  FIG. 3A  from the superior end; 
         FIG. 3D  is view of the introducer sheath valve assembly back cap depicted in  FIG. 3A  from the superior end; 
         FIG. 3E  is a partial perspective of the joint formed when the capsule depicted in  FIG. 2  is inserted in the valve assembly depicted in  FIG. 3A  with the knob tightened inside the back cap; 
         FIG. 4  is a perspective view depicting the fixture used to assemble a loading capsule of the present invention; 
         FIG. 4A  is a cross-sectional view of the fixture depicted in  FIG. 4  across the line  4 A- 4 A; 
         FIG. 4B  is a view of the fixture depicted in  FIG. 4  from the superior end; 
         FIG. 4C  is a cross-sectional view of a loading capsule of the present invention assembled using the fixture depicted in  FIG. 4 ; 
         FIG. 5  is a perspective view of an alternate embodiment of the pusher assembly depicted in  FIG. 1  with multiple pusher buttons; 
         FIG. 5A  is a cross-sectional view of the stent pusher button depicted in  FIG. 5  taken at line  5 A- 5 A; 
         FIG. 5B  is a cross-sectional view of the superior pusher button depicted in  FIG. 5  taken at line  5 B- 5 B; 
         FIG. 5C  is a cross-sectional view of the pusher assembly tip depicted in  FIG. 5  taken at line  5 C- 5 C; 
         FIG. 5D  is a perspective view of the pusher assembly depicted in  FIG. 5  with a compressed attachment stent and graft held in place by a loading capsule; 
         FIG. 6A  is an enlarged perspective view of a crimp sleeve of the present invention; 
         FIG. 6B  is view of the crimp sleeve depicted in  FIG. 6A  from the inferior end; 
         FIG. 6C  is a perspective view of a crimp sleeve installed over the crimp area formed between a pusher button and pusher assembly tube of a the present invention; 
         FIG. 7  is a perspective view of an alternate embodiment of the pusher assembly depicted in  FIG. 1  with the components joined via threaded hypotube sections; 
         FIG. 7A  is a cross-sectional view of the pusher button depicted in  FIG. 7  taken at line  7 A- 7 A; 
         FIG. 7B  is a perspective view of the flexible tip of the pusher assembly depicted in  FIG. 7 ; 
         FIG. 7C  is a cross-sectional view of the flexible depicted in  FIG. 7B  taken at line  7 C- 7 C; 
         FIG. 8  is a perspective view of a locking system of the present invention with the two cap nuts disassembled from the center body with a Pebax tube, pusher assembly inner tube, and guidewire passageway inserted therein; 
         FIG. 8A  is a cross-sectional view of the small diameter cap nut depicted in  FIG. 8  taken at line  8 A- 8 A; 
         FIG. 8B  is a cross-sectional view of the large diameter cap nut depicted in  FIG. 8  taken at line  8 B- 8 B; 
         FIG. 8C  is a view of the small diameter cap nut depicted in  FIG. 8  from the superior side; 
         FIG. 8D  is a cross-sectional view of the center body depicted in  FIG. 8  taken at line  8 D- 8 D; 
         FIG. 8E  is a view of the large diameter cap nut depicted in  FIG. 8  from the inferior side; 
         FIG. 9  is an enlarged perspective view of a locking system of the present invention with the two cap nuts installed on the center body; 
         FIG. 10  is a partial perspective view of an embodiment of a bifurcated endovascular graft main body component with the attachment stent connector holes located to facilitate a pinwheel folding method; 
         FIG. 11  is a partial perspective view of the bifurcated endovascular graft main body component depicted in  FIG. 10  with the stent struts compressed and the graft material forming a smooth “cloverfold” pattern about a pusher assembly tube; 
         FIG. 12A  is a cross-sectional view of the endovascular graft main body component depicted in  FIG. 11  taken at line  12 - 12  before the graft is wrapped around itself; 
         FIG. 12B  is a cross-sectional view of the endovascular graft main body component depicted in  FIG. 11  taken at line  12 - 12  as the graft is wrapped around itself; 
         FIG. 12C  is a cross-sectional view of the endovascular graft main body component depicted in  FIG. 11  taken at line  12 - 12  with the graft compressed for delivery; 
         FIG. 12D  is a partial cross-sectional side view, depicting a graft loaded within a delivery catheter; 
         FIG. 13  is a partial perspective view, depicting an alternate delivery system of the present invention having an outer jacket covering a single piece flexible tip attached to a hypotube/lumen; 
         FIG. 13A  is a cross-sectional view of the delivery system depicted in  FIG. 13  taken at line  13 A- 13 A; 
         FIG. 13B  is a perspective view, depicting the single piece flexible tip of the delivery system shown in  FIG. 13  with the cone tip and proximal stent stop; 
         FIG. 13C  is a perspective view, depicting the hypotube/lumen of the delivery system shown in  FIG. 13 ; 
         FIG. 14  is a partial perspective view, depicting an alternate embodiment of the delivery system shown in  FIG. 13  having a separate molded flexible tip and distal stent stop attached to a hypotube/lumen; 
         FIG. 14A  is a cross-sectional view of the delivery system depicted in  FIG. 14  taken along line  14 A- 14 A; 
         FIG. 14B  is a perspective view, depicting the molded flexible inferior stent stop of the delivery system shown in  FIG. 14 ; 
         FIG. 14C  is a perspective view, depicting the molded flexible tip of the delivery system shown in  FIG. 14 ; 
         FIG. 14D  is a perspective view, depicting the hypotube/lumen of the delivery system shown in  FIG. 14 ; 
         FIG. 15  is a partial perspective view, depicting an alternate embodiment of the delivery system shown in  FIG. 13  having a separate molded cone shaped flexible tip, hard superior stent stop, and hard inferior stent stop attached to a hypotube/lumen; 
         FIG. 15A  is a perspective view, depicting the hard inferior stent stop of the delivery system shown in  FIG. 15 ; 
         FIG. 15B  is a perspective view, depicting the hard superior stent stop of the delivery system shown in  FIG. 15 ; 
         FIG. 15C  is a perspective view, depicting the molded cone-shaped flexible tip of the delivery system shown in  FIG. 15 ; 
         FIG. 15D  is a perspective view, depicting the hypotube/lumen of the delivery system shown in  FIG. 15 ; 
         FIG. 16A  is a partial perspective view, depicting an alternate embodiment of the delivery system shown in  FIG. 13  having a tapered outer jacket; 
         FIG. 16B  is a partial perspective view, depicting the delivery system shown in  FIG. 16A  restraining a compressed endovascular graft and inserted into the vasculature of a patient over a guidewire; 
         FIG. 16C  is a partial perspective view, depicting the delivery system shown in  FIG. 16A  inserted into the vasculature of a patient and its tapered outer jacket retracted to partially deploy the compressed stent; and 
         FIG. 16D  is a partial perspective view, depicting the delivery system shown in  FIG. 16A  inserted into the vasculature of a patient and its tapered outer jacket retracted to fully deploy the compressed stent. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention relates to systems and methods for accurately delivering and deploying the individual components of a endovascular graft at a treatment site within a patient&#39;s vasculature. 
     In one aspect, the invention is embodied in a system and method that accomplishes delivering a main graft component within vasculature using a delivery system embodying a jacket which is retracted to deliver the main graft component. The jacket is left within the vasculature and the remaining portions of the delivery system are withdrawn. The jacket is then employed as a sheath and jacket for the advancement and delivery into vasculature of subsequent medical devices. The jacket includes a hemostatic seal that prevents bleeding when exchanging capsules. Each of the subsequent devices is initially held in a capsule that mates with a proximal end of the jacket and is advanced within the jacket using a pusher device. At the time of deployment, the pusher can be held stationary and the sheath withdrawn to deploy the subsequent devices at a desired location within the vasculature. 
       FIGS. 1-1E  shows a delivery system  110  that is one aspect of the present invention. The delivery system is defined by an introducer sheath  111  that is configured to receive a medical device such as an endovascular graft component  120  (shown in phantom in  FIG. 1 ). The introducer sheath  111  is also configured to receive an initial pusher device  121  having a distal or inferior end (not shown) which extends exterior a patient&#39;s body when the introducer sheath assembly  111  is placed within vasculature. 
     In a first step involving the introducer  111  assembly, conventional techniques are employed to gain access to a patient&#39;s vasculature. A guidewire  127  is then placed within the vasculature and advanced beyond a repair site  123 , which is shown in  FIG. 1A  as an aneurysm but can be any diseased or damaged blood vessel. The introducer sheath  111  loaded with a medical device  120  is advanced along the guidewire  127  to the repair site and while holding the initial pusher device  121  stable, the introducing sheath  111  is retracted thereby deploying the medical device  120  at the repair site  123 . The pusher device  121  can then be withdrawn from the patient&#39;s vasculature leaving the introducer sheath  111  available for delivering additional medical devices within the patient&#39;s vasculature. 
     As shown in  FIG. 1E , a loading capsule  112 , and a rapid exchange pusher assembly  113  can be employed to deliver a subsequent compressed medical device or endovascular graft component  128  within vasculature. The introducer sheath  111 , sufficiently long to reach the treatment site, acts as a conduit to maneuver the individual components of a endovascular graft  128  into position and restrain them in a compressed state until they are deployed in the body. The introducer sheath  111  acts as the delivery conduit, thereby obviating the need for a second sheath with a larger diameter to facilitate the exchange of individual catheters for each component delivered. The loading capsule  112  is a short restraining sheath that covers and retains the self-expanding endovascular graft  128  in a compressed state until it is transferred to the introducer sheath  111  for delivery to the treatment site  123 . The inner diameter of the loading capsule  112  is approximately the same as the inner diameter of the introducer sheath  111  and may have a fitting or lock at its superior end that is designed to mate with a similar fitting or lock at the inferior end of the introducer sheath. The pusher assembly  113  is similar to the inner lumen of the standard delivery system and is defined by an inner tube  116  and a pusher button  117 . The inner tube  116  is further defined by an inferior end  114 , a tapered superior end  115 , an exit notch  119 , and a guidewire passageway  118  therethrough between the superior end  115  and exit notch  119 . The guidewire passageway  118  facilitates placing the pusher assembly  113  over a guidewire  127  inserted in the introducer sheath. The rapid exchange exit notch  119  facilitates communication and control of the guidewire external to the pusher assembly  113  when the associated endovascular graft component  128  is delivered to and deployed at the treatment site. The endovascular graft component  128  is compressed for delivery about the pusher assembly tube  113  which extends past the superior end of the loading capsule  112 . The pusher button  117  rests against or engages the compressed component in a manner to effect longitudinal advancement thereof and is covered by the loading capsule  112 . There is a separate loading capsule and pusher assembly for each component delivered to the treatment site for deployment and assembly into the implanted endovascular graft  128 . 
     Using this rapid exchange delivery system, a single operator can safely and efficiently deliver multiple self-expanding endovascular graft components within a patient&#39;s vasculature. The guidewire  127  is inserted in the guidewire passageway  118  at the superior end  115  of the pusher assembly  113  and threaded therethrough until it emerges from the rapid exchange exit notch  119 . Once the guide wire  127  is threaded through passageway  118 , the loading capsule  112  is attached to the introducer sheath  111 . While holding the guidewire with one hand to prevent it from inadvertently moving, the operator pushes the inferior end of the pusher assembly with the other hand, thereby moving the compressed endovascular graft component and pusher button  117  through the loading capsule into the introducer sheath. By continuing to push the inferior end of the pusher assembly, the operator moves the compressed endovascular graft component to the superior end of the introducer sheath. With the pusher assembly held in a fixed position, the operator then retracts the introducer sheath, thereby allowing the compressed self-expanding endovascular graft component to deploy. The operator then retracts the pusher assembly with one hand, while holding the guidewire steady with the other hand in a rapid exchange manner. Successive compressed self-expanding endovascular graft components are delivered and deployed using this procedure. 
     In a preferred embodiment, the guidewire passageway  118  is a stainless steel hypotube with a wall thickness in the range of 0.003-0.010 inches or wall thickness-to-outer diameter ratio of 1:6 of which provides a strong, solid core which will not break or buckle under average conditions. The hypotube runs the entire length of the pusher assembly inner tube  116  and serves as a path for the guidewire  127  as well as providing increased rigidity for the delivery system  110  and a frame to which other components of the system may be attached. The hypotube may be a single segment or several segments of the same inner diameter or ever-increasing diameter. In the case of multiple segments, the hypo-tubes may be linked by welding, threading, gluing, or crimping. Alternately, multiple segments of hypotube may be linked by connecting threads or short tubes that overlap the segments and are crimped at both ends. 
     By providing an inner core of a single material as the guidewire passageway, obstruction of the guidewire due to multiple transitions of different materials and inner diameter is avoided. It is contemplated that a hypotube guidewire passageway may be utilized in any catheter system requiring the passage of a guidewire or other solid through a small diameter without obstruction. 
       FIG. 2  depicts an alternate embodiment of the loading capsule shown in  FIG. 1 . The loading capsule  212  is defined by a short soft or hard plastic tube  154  such as polycarbonate, FEP, PTFE or HDPE surrounded by a shorter metal sleeve  155 , the inferior ends of which are connected to a valve assembly  156 . The valve assembly  156  is further defined by a through hole  158  and flushport  161 . The tube  154  provides encapsulation for the compressed implant  128  such that it is isolated from the metal sleeve  155 . The metal sleeve  155  provides a solid surface for engaging the inferior end of the introducer sheath  111  in order to transfer the compressed implant  128  and advance it to the implant site. The valve assembly  156  through hole  158  allows the pusher assembly  113 , which protrudes from the inferior and superior ends of the loading capsule  212 , to advance the compressed implant  128  from the tube  154  through the introducer sheath  111  to the implant site. The internal diameters of the tube  154  and metal sleeve  155  as well as the distance by which the tube  154  extends beyond the metal sleeve  155  in the superior direction are consistent with that of the introducer sheath, thereby allowing a smooth transition when the loading capsule  212  is mated to the introducer sheath. 
     One method of mating the loading capsule  212  to the introducer sheath  111  is shown in  FIGS. 3A-E . The introducer sheath has a valve assembly  162  attached to the inferior end. The valve assembly is further defined by a knob  163  and back cap  164 . 
     The knob  163  has a small diameter inferior portion  177 , a wide diameter middle portion  165 , flat extensions  166 , external threads  167  near its superior end, a tapered nose  169 , and a through hole  168 . The inner diameter of the through hole  168  is slightly larger than the outer diameter of the loading capsule  212  metal sleeve  155 . The tapered nose further embodies slots that define fingers  170 . These fingers are bent inwards when sufficient pressure is applied. The flat extensions  166 , which extend longitudinally from the wide diameter middle portion to the inferior end, facilitate turning the knob. 
     The back cap  164  is further defined by a flared inferior end  173 , a through hole  174 , threads  175  at the inferior end, an internal taper  176  toward the superior end, leading to a step-down diameter  178 . The inner diameter and internal threads  175  of the through hole  174  accommodate the external threads  167  of the knob  163 . The internal taper engages the tip of the knob, thereby causing the fingers to bend inward when the knob is screwed into the back cap. The step-down diameter is slightly larger than the outer diameter of the plastic tube  154  of the loading capsule  212 . 
     To mate the loading capsule  212  to the introducer sheath  111 , the knob  163  is loosened from the back cap by unscrewing it in the inferior direction. The superior end of the loading capsule  212  is then inserted through the knob through hole  168  and inside the back cap  164  until the metal sleeve  155  reaches the step-down diameter  178 . The step-down diameter  178  accommodates the tube  154 , but prevents the metal sleeve  155  from advancing any further into the introducer sheath. Since the distance by which the tube  154  extends beyond the metal sleeve  155  in the superior direction is consistent with the length of the step-down diameter, the superior end of the tube  154  abuts the inferior end of the introducer sheath  111 , thereby providing a smooth transition between the loading capsule and introducer sheath  111  inner diameters. When the knob  163  is tightened onto the back cap  164 , the internal taper  176  of the back cap causes the fingers  170  of the knob to bend inward, thereby engaging the metal sleeve and locking it in place ( FIG. 3E ). 
     Once the metal sleeve is locked in place and the contents of the loading capsule are pushed through the introducer sheath to the implant site, the flat extensions of the knob facilitate torquing the introducer sheath as it is retracted. By torquing the introducer sheath, the operator may twist the implant as it is deployed, thereby facilitating correction of any twisting which occurred when the graft was compressed for delivery. The operator can use fluoroscopy to align the radio opaque markers  45  of the graft ( FIG. 10 ) as it is deployed. 
     An alternate method of mating of the loading capsule  212  to the introducer sheath  111  is a small hard plastic “snap-fit” (not shown) attached to the superior end of the metal sleeve  155 . The “snap-fit” has a key profile that matches a key profile on the inferior surface of the introducer sheath  111 . The “snap-fit” prevents axial displacement of the loading capsule  212  and introducer sheath  111  as the compressed endovascular graft component  128  is transferred and the key profile prevents slippage under torque. 
     The hard plastic “snap-fit” may be attached to the metal sleeve by bonding with adhesive over a sand blasted surface. Alternately, the “snap-fit” may be attached by heat-staking to a knurled surface; heating the metal sleeve knurled surface so that when the hard plastic part is pressed against it, a thin layer of the plastic melts, thereby filling the grooves in the knurled surface and hardening over the metal sleeve as it is cooled. 
       FIGS. 4-4C  depict a staged and threaded steel fixture  185  to facilitate precise assembly of the introducer sheath distal end. The fixture  185  is defined by diametrical transitions  195  along its axis, threads  196  near the inferior end, and an inferior knob  202 . The first component of the loading capsule assembly  212  is fixed in place by the threads  196  and inferior-most diametrical transition  195 . The other components are screwed to the first component, the subsequent diametrical transitions  195  maintaining the proper axial spacing between them. The assembly of the components is as precise as the fixture  185 , with minimum variation between the individual components, thereby producing an introducer sheath distal end which facilitates smooth docking and transfer of the compressed implant  128  from the loading capsule  212 . It is contemplated such a fixture may be used whenever a device is assembled from components requiring stepped assemblies to precisely match each other with consistent internal distances between them. 
       FIGS. 5-5D  depict an alternate embodiment of the pusher assembly shown in  FIG. 1 . The pusher assembly  213  is defined by a tapered flexible tip  122  and three pusher buttons mounted on the inner tube  116 ; an inferior graft pusher button  117 , a stent pusher button  120 , and a superior pusher button  121 . The tapered flexible tip  122 , which has a hollow center to allow the guidewire passageway  118  to pass therethrough, facilitates maneuvering the pusher assembly into and through the introducer sheath  111 . It is contemplated that the flexible tip may be a stand-alone component (as shown) or may be attached to the superior end of the superior pusher button  121 . The pusher buttons  117 ,  120 ,  121  facilitate packing the compressed endovascular graft  128  for delivery and control of the endovascular graft  128  when it is deployed. Each pusher button is an annular cylinder defined by a conical inferior portion  123 , a cylindrical superior portion  124 , and a through hole  125 . The conical inferior portion facilitates retracting the delivery system into the sheath after the stent and graft have been deployed. The superior portion, which has an outer diameter approximately that of the compressed components, transmits force to the superior end of the delivery system when it is moved through the introducer sheath and minimizes the likelihood of the compressed components catching on the introducer sheath as the pusher assembly is maneuvered to the treatment site. Additionally, the conical inferior portion of the graft and stent pusher buttons further facilitate compressing the component around the pusher assembly tube. The through hole  125  allows the pusher assembly tube  116 , and guidewire passageway therein, to pass through each pusher button. It is contemplated that the pusher buttons may be located at any axial position along the component and that additional pusher buttons may be provided to facilitate control of different portions of the same component. 
     The stent pusher button  120  may have axial grooves  126  along the external surface to facilitate packing the extended struts  43  or connector loops  44  of an attachment stent  40  (see  FIG. 5D ). Alternately, the axial grooves  126  may be used with a separately-deployed attachment or support stent having enlarged inferior stent ends in order to facilitate control of the stent prior and during deployment. 
     The pusher buttons  117 ,  120 ,  121  and flexible tip  122  may be attached to the pusher assembly tube  116  by crimping the inferior portion  123  to the pusher assembly tube and covering the crimp area with a custom funnel-like crimp sleeve  135  as shown in  FIGS. 6-6C . The crimp sleeve  135  is defined by an inferior end  136  having an outer diameter that matches the outer diameter of the pusher assembly inner tube  116 , a tapered middle portion  138 , and a superior end  137  having an inner diameter not exceeding the diameter of the widest portion of the pusher button or flexible tip. The crimp sleeve  135  may be made of either steel or similar characteristic material depending on the application and sterilization method. By covering the crimped area with the crimp sleeve  135 , the transition between the pusher assembly inner tube  116  and pusher button is completed without raised edges that can generate interference when the pusher assembly  213  is retracted into the introducer sheath  111  after the implant is deployed. It is contemplated that a crimp sleeve  135  may be used in any catheter system that requires consistent and smooth transitions between changing diameters along its length. 
     To apply the crimp sleeve  135 , the narrow diameter inferior end  136  is slid over the pusher assembly tube  116 . Next, the pusher button  117 ,  120 ,  121  or flexible tip  122  is attached to the pusher assembly inner tube  116  by crimping the inferior portion  123  to the tube. Finally, the crimp sleeve  135  is slid forward with its tapered portion  138  covering the crimp area and its superior end  137  bonded next to the superior portion  124  of the pusher button or flexible tip. In a preferred embodiment, the crimp sleeves  135  are made of stainless steel and bonded in place using a biocompatible adhesive such as Loctite  380 . 
     In a preferred embodiment the pusher assembly  213  at its distal end is a Pebax shaft  179  with a stainless steel tube  901  ( FIG. 8 ). The outer diameter of the Pebax shaft  179  is reduced at the inferior end to fit inside the stainless steel tube  901  such that the outer diameter of the pusher assembly  213  remains consistent throughout its length. The stainless steel tube  901  at the inferior end increases the rigidity of the pusher assembly  213 , thereby facilitating a more controlled and precise deployment of the implant. It is contemplated to use a stainless steel tube  901  to reinforce the pusher assembly  213  whenever retraction forces are increased by the size of the implant or tortuosity of the anatomy. It is also contemplated that a stainless steel tube  901  may be used to reinforce a pusher assembly in catheter based delivery systems with an outer diameter of 8 Fr to 18 Fr. Also in the preferred embodiment, the gap between the Pebax shaft  179  and introducer sheath  111  is 0.006″+0.002″. 
       FIGS. 7-7C  depict another alternate embodiment of the pusher assembly shown in  FIG. 1  which utilizes threads to attach the components of the pusher assembly. The pusher assembly  313  is defined by a tapered flexible tip  222 , a pusher button  220 , and sections of threaded hypotube  129 . The tapered flexible tip is over molded on a core hypotube section  129  having a guidewire passageway  118  therethrough and external threads  139  at the inferior end. The pusher button  220  is defined by external axial grooves  126  and a through hole  125  with internal threads  144  which mate with the hypotube  129  external threads  139 . The pusher assembly  313  is formed by attaching the superior end of the pusher button  220  to the threaded inferior end of the flexible tip  222  core hypotube  129  and attaching another hypotube section  129  with threads  139  at its superior end to the inferior end of the pusher button  220 . 
     It is contemplated that additional pusher buttons  220  with internal threads may be added to the pusher assembly  313  by utilizing hypotube sections  129  having external threads  139  at both the superior and inferior ends. In a preferred embodiment, each hypotube section  129  has approximately five threads  139  of size #0-80 UNF, each pusher button  220  has matching internal threads, and the flexible tip  222  is formed by plastic injection molding over a core hypotube section  129  with a mechanical feature such as a crimp to prevent rotation or slippage. 
     Since the pusher assembly inner tube  116  must be long enough to allow the graft to be pushed through the introducer sheath  111  to the implant site, such as to the abdominal aorta, the tube  116  may extend a considerable distance in the inferior direction from the inferior pusher button  117  ( FIG. 5 ). A hollow Pebax tube  179  may enclose the pusher assembly inner tube  116  from the inferior end  114  of the pusher assembly to the inferior pusher button  117  in order to maintain a consistent diameter for the delivery system  110  ( FIG. 1E ).  FIGS. 8-8E  show a method of securing the pusher assembly inner tube  116  to the hollow Pebax tube  179  and stainless steel tube  901  at the inferior end  114  of the delivery system  110 . The locking system  181  is defined by a disc shaped center body  182 , an inferior cap nut  197 , and an superior cap nut  203 . The center body  182  is further defined by a grip  187  around its center edge, an inferior protruding cylinder  188  with external threads  208 , a superior protruding cylinder  189  with external threads  209 , and a through hole  192 . The inferior cylinder  188  has a slotted nose  193  which defines a series of fingers. The superior cylinder  189  has a tapered end  194 . The inferior  197  and superior  203  cap nuts are further defined, respectively, by grips  198 ,  204 , internal threads  199 ,  205 , tapered internal ends  201 ,  207 , and through holes  200 ,  206  at their axis. 
     Note that the superior cap nut  203  through hole  206  have a larger diameter than the inferior cap nut  198  through hole  200 . The wide diameter superior cylinder  189  and superior cap nut  203  through hole  206  facilitate securing the hollow Pebax tube  179  and steel tube  901  to the center body  182 . The wide diameter cap nut  203  through hole  206  facilitates passing the Pebax tube  179 , pusher assembly inner tube  116 , and steel tube  901  therethrough. The pusher assembly inner tube  116  passes through the center body  182 , emerging from the slotted end  193  of the inferior cylinderl  88 . The Pebax tube  179  and pusher assembly steel tube  901  have flared inferior ends which are sandwiched between the internal taper  207  of the superior cap nut  203  and tapered end  194  of the superior cylinder  189  when the superior cap nut  203  is tightened onto the superior protruding cylinder  189 , thereby securing them to the center body  182  when the superior cap nut  203  is tightened. 
     The small diameter inferior cylinder  188  and inferior cap nut  197  facilitate securing the pusher assembly inner tube  116  to the center body  182 . The inferior cap nut  197  through hole  200  facilitates passing the pusher assembly inner tube  116  therethrough. When the inferior cap nut  197  is tightened over the slotted nose  193  of the inferior cylinder  188 , the fingers are compressed downward by the internal taper  201  of the inferior cap nut  197 , thereby gripping the pusher assembly inner tube  116  and locking it in place. This way the pusher assembly inner tube  116 , the Pebax tube  179  and pusher assembly steel tube  901  are mechanically secured to the center body  182 . 
     The locking system  181  facilitates using a single pusher assembly inner tube  116  tube length for all components delivered to the treatment site instead of a different length for each component. By sliding the pusher assembly inner tube  116  forwards or backwards through the locking system  181 , the desired exposure length at the packing location is achieved. Furthermore, the locking system  181  eliminates the need to use epoxy-bond to attach the pusher assembly inner tube  116  to the Pebax tube  179  and reduces the amount of crimps required during assembly. Moreover, as shown in  FIG. 9 , the center body  182  and cap nuts  197 ,  203  form a cylindrical handle grip for the pusher assembly  213  which provides an improved grip from a flat handle. It is contemplated that the locking system  181  may be used in any catheter-based delivery system intended to transport a range of implant components of varying lengths. 
     To achieve the smallest diameter delivery profile, the graft implant must be compressed such that irregular folds or lumps are minimized when it is loaded into the loading capsule  112 . Optimum compression of a main body component with an attachment stent already connected is achieved by folding the main graft body such that a pinwheel pattern is generated. Locating the attachment stent connector holes  35  as shown in  FIG. 10  facilitates the pinwheel folding method. The connector holes are equally spaced around the circumference of the neck  831  of the main body component  830  such that two of the four connector holes are axially aligned with the bifurcation between the limb portions  833 ,  834 . 
     As shown in  FIG. 11 , a smooth “cloverfold” pattern is created when the attachment stent  40  is collapsed for delivery. The attachment stent struts  43  and connector holes  35  are pulled together, with the graft material between the attachment points pulled outward, thereby creating the “clover” or star-like pattern. With the connector holes spaced as shown, the “cloverfold” continues smoothly from the neck  831  through the limbs  833 ,  834 . 
     With the attachment stent collapsed and the “cloverfold” pattern heat set with an iron, the pusher assembly tube  116  is inserted through the trunk  831  and ipsi-lateral limb support portion  833 . As shown in  FIGS. 12A ,  12 B, and  12 C, the “cloverfolds” are then wrapped over each other, like a pinwheel or propeller, as the graft main body component  830  is wrapped tightly around the pusher assembly inner tube  116 . 
     Teflon tape may be used to hold the superior end of wrapped graft until it is inserted into the loading capsule  112 , the tape being unwrapped as the compressed graft enters the capsule. The graft may be loaded by hand or with the aid of a tapered mandrel or mechanical loading machine. Attachment stent loading eyelets (not shown) may be provided to facilitate loading of the stent  40  and attached main body component  830 . 
     Although the pinwheel packing method is illustrated by an attachment stent  40  with extended stent struts  43  attached to connector holes  35  in the neck  831  of the main body component  830 , it is contemplated that the pinwheel packing method may be used with any of the attachment methods described herein as long as the attachment locations of the attachment stent  40  are as shown in  FIG. 10 . It is further contemplated that the pinwheel packing method may be applied to part or all of a graft and may be used whenever a small packing profile is desired for an endovascular graft. 
     The markers  45  are placed on the surface of the graft material  830  so as to form a vertical line that defines the contra-lateral side  834  of the implant  830  (see  FIG. 10 ). The graft  830  is ironed or folded so that the markers  45  are on the valley of one of the folds. Additional markers are contemplated to be placed at the bifurcation of the graft  830  and at a superior end thereof. It is also contemplated that the markers  45  be made from 1 mm platinum coils. The marker  45  at the superior end of the graft can embody a 2.5 mm coil. When the graft  830  is on the pusher assembly inner tube  116 , all the folds are wrapped around in the same direction, keeping in mind that relative twisting of the graft implant  830  between the neck  831  and limbs  833 ,  834  is unacceptable. For the cloverleaf fold, the markers will lie on the valley of one of the folds. As the folds are wrapped around the pusher assembly inner tube  116 , the line of markers on the valley of the fold will lie next to the inner tube  116 . This maintains alignment between the graft and stent during deployment. The mass of the markers in a line along side the inner tube allows for proper orientation. 
     Although various folding techniques are contemplated, one embodiment is to keep the markers aligned at the outer surface of the delivery system to maximize their visibility and aid in visual inspection of the packing process as well as to allow the user to verify and correct for proper orientation of the implant under fluoroscopy prior to deployment. It is contemplated that this folding technique may be used for any catheter delivered device with a graft-like component for which a specific radial orientation is desired upon deployment. Folding the main body component  830  graft implant such that the radio opaque markers  45  remain as far from the center of the delivery system as possible when packed facilitates visualization under fluoroscopy when the markers are separated far enough away from the central hypotube of the pusher, then small rotations of the delivery system tell the user which side is the contralateral side of the implant. The graft is folded and loaded into the system so that the resulting pack will have the marker bands  45  aligned along the outer surface (see  FIG. 12D ). 
       FIGS. 13A-C  show an alternate delivery system  250  for a self-expanding attachment stent  40  and graft implant  830 . The delivery system  250  is defined by an outer jacket  251  and inner shaft  252 . The inner shaft  252  is defined by a single piece flexible tip  253  mounted on a hypotube/lumen shaft  260 . The flexible tip  253  is molded of a material such as Pebax, Hytrel, Silicone, or similar material and is defined by a cone tip  254 , superior stent stop  255 , stent inner support  256 , inferior stent stop  257 , internal molded mechanical stop  258 , and through hole  259  therethrough which tapers near the superior end. Axial grooves  126  in the inferior stent stop  257  accommodate the extended struts  43  or other structure of an attachment stent  40 . The through hole  259  of the single piece flexible tip  253  allows it to be mounted on the hypotube/lumen shaft  260 . The hypotube/lumen shaft  260  is defined by a mechanical stop  261  attached to the superior end and a through hole  262  therethrough with the same diameter as the tapered end of the single piece flexible tip  253  through hole  259 . The hypotube through hole  262  allows the assembled delivery system  250  to be threaded onto a guidewire  127 . The single piece flexible tip  253  is attached to the hypotube  260  with glue by inserting the hypotube  260  into it and mating their respective mechanical stops  258 ,  261 . 
     After the self-expanding stent  40  and graft implant  830  is compressed about the inner shaft  252  and the delivery system  250  is advanced to the treatment site, the stent  40  and implant  830  are deployed by retracting the outer jacket  251 . It is contemplated that the delivery system  250  may be used to deliver and deploy any self-expanding stent  40  and graft implant  830  with a compressed diameter of 10 Fr to 25 Fr. 
     An alternate embodiment of the delivery system is shown in  FIGS. 14-14D . The delivery system  350  has an outer jacket  251  and inner shaft  352 . The inner shaft  352  is defined by a molded flexible tip  354  and a molded flexible inferior stent stop  357  mounted on a hypotube/lumen shaft  360 . The flexible tip  354  is molded of a material such as Pebax, Hytrel, Silicone or similar material and is defined by a molded internal mechanical stop  258 , inferior protrusion  263 , and through hole  259  therethrough, the through hole  259  tapering near the superior end. The inferior end of the flexible tip  354  serves as a superior stent stop. The flexible inferior stent stop  357  is defined by axial grooves  126 , a superior protrusion  264 , internal mating grooves  265 , and a through hole  259  therethrough. The through holes  259  of flexible tip  354  and inferior stent stop  357  allow them to be mounted on the hypotube/lumen shaft  360 . The hypotube/lumen shaft  360  is defined by a mechanical stop  261  welded to the superior end, round spot welds  266 , and a through hole  262  therethrough with the same diameter as the tapered end of the flexible tip  354  through hole  259 . The hypotube  360  through hole  262  allows the assembled delivery system  350  to be threaded onto a guidewire  127 . 
     The flexible tip  354  is attached to the hypotube  360  with glue by inserting the hypotube  360  through the inferior protrusion  263  and mating their respective mechanical stops  258 ,  261 . The inferior stent stop  357  is attached to the hypotube  360  with glue by inserting the hypotube  360  through the superior protrusion  264  and mating the round spot welds  266  with the internal mating grooves  265 . Heat shrink tubing (not shown) further binds the flexible tip  354  and inferior stent stop  357  to the hypotube  360 . 
     Another alternate embodiment of the delivery system is shown in  FIGS. 15-15D . The delivery system  450  has an outer jacket  251  and inner shaft  452 . The inner shaft  452  is defined by a molded cone-shaped flexible tip  454 , a hard superior stent stop  455 , and a hard inferior stent stop  457  mounted on a hypotube/lumen shaft  460 . The flexible tip  454  is defined by a molded internal mechanical stop  358  and through hole  259  therethrough, the through hole  259  tapering near the superior end. The hard superior stent stop  455  is made of hard plastic or steel and is defined by a center body  268  with the same outer diameter as the inferior end of the flexible tip  454 , a superior protrusion  269 , an inferior protrusion  270 , and through hole  259  therethrough. The hard inferior stent stop  457  is made of hard plastic or steel and is defined by axial grooves  126 , a superior protrusion  264 , and a through hole  259  therethrough. The through holes  259  of flexible tip  454 , hard superior stent stop  455 , and hard inferior stent stop  457  allows them to be mounted on the hypotube/lumen shaft  460 . The hypotube/lumen shaft  460  is defined by round spot welds  266  and a through hole  262  therethrough with the same diameter as the tapered end of the flexible tip  454  through hole  259 . The hypotube  460  through hole  262  allows the assembled delivery system  450  to be threaded onto a guidewire  127 . 
     The hard superior stent stop  455  is attached to the flexible tip  454  with glue by inserting the superior protrusion  269  into the molded internal mechanical stop  358  until the superior stent stop  455  center body  268  is flush with the inferior end of the flexible tip  454 . The mated hard superior stent stop  455  and flexible tip  454  are attached to the hypotube  460  with glue by inserting the hypotube  460  through the inferior protrusion  270 , center body  268 , and superior protrusion  269  of the superior stent stop  455  and into the mechanical stop  259  of the flexible tip  454 . The superior-most spot weld  266  of the hypotube  460  prevents the hard superior stent stop  455  from moving in the inferior direction. The hard inferior stent stop  457  is attached to the hypotube  460  with glue by sliding the hypotube  460  through the superior protrusion  264  until the inferior-most spot weld  266  on the hypotube  460  prevents further movement. Heat shrink tubing (not shown) further binds the flexible tip  454 , hard superior stent stop  455 , and inferior stent stop  457  to the hypotube  460 . 
     Another alternate embodiment of the delivery system is shown in  FIGS. 16A-16D . The delivery system  550  has a tapered outer jacket  551  and inner shaft  552 . The inner shaft  552  is defined by a single piece flexible tip  553  having a cone tip  554  with a wider outer diameter than the inferior stent stop  557 . The inferior stent stop  557  is further defined by a stent retention mechanism (illustrated as axial grooves  126 ) intended to retain the distal end (illustrated as extended struts  43 ) of a compressed attachment stent  40  having attachment hooks or barbs  86  until the outer jacket  551  is fully retracted. The outer jacket  551  is further defined by a localized increased thickness that forms a ring  271  near a tapered superior end. The tapered superior end of the outer jacket  551  promotes gradual deployment, or “flowering”, of the compressed stent  40  when the jacket  551  is retracted. The ring  271  isolates the attachment hooks or barbs  86  of the partially deployed stent  40  from the walls of the patient&#39;s vasculature  160 , thereby allowing the stent  40  to be relocated prior to full deployment. 
     As shown in  FIG. 16B , the compressed stent  40  is restrained in a compressed state about the inner stent support  256  and the attached graft  30  is restrained in a compressed state about the hypotube/lumen shaft  260  by the tapered outer jacket  551 . The compressed stent  40  and graft  30  are delivered to the implant site within the patients vasculature  160  by maneuvering the delivery system  550  over a guidewire  127 . 
     As shown in  FIG. 16C , when the outer jacket  551  is retracted, the compressed stent  40  begins to partially deploy, its proximal end moving radially away from the inner shaft  552 . If the outer jacket  551  is not retracted past the inferior end of the inferior stent stop  557 , the axial grooves  126  restrain the distal end of the stent  40 , thereby preventing the stent  40  from fully deploying and allowing it to be maneuvered within the patient&#39;s vasculature  160 . The ring  271  at the tapered superior end of the outer jacket  551  isolates the partially deployed hooks or barbs  86  from the walls of the patient&#39;s vasculature  160 , thereby preventing damage to the vasculature  160  if the partially deployed stent  40  is moved. By further maneuvering the delivery system  550 , the partially deployed stent  40  may be repositioned using fluoroscopy, thereby allowing it to be properly relocated before it is deployed. 
     As shown in  FIG. 16D , when the outer jacket  551  is retracted past the inferior end of the inferior stent stop  557 , the distal end of the stent  40  is released from the axial grooves  126  and fully deploys. Retracting the outer jacket  551  further causes the compressed graft  30  to expand radially from the hypotube/lumen shaft  260  into the patient&#39;s vasculature  160 . Once the attachment stent  40  and attached graft  30  are fully deployed, the inner shaft  552  and hypotube lumen shaft  260  are retracted through the neck  31  of the deployed graft  30 . 
     Although the stent retention mechanism is shown as axial grooves  126  in  FIGS. 16A-16D , it is contemplated that any method known in the art of retaining the distal end of a stent may be used with the tapered outer jacket  551  with a superior ring  271 . It is also contemplated that the tapered outer jacket  551  with superior ring  271  may be used for the delivery and deployment of any device having a physically engaging mechanism with a compressed outer surface diameter of 8 Fr. and larger. 
     It will be apparent from the foregoing that, while particular forms of the invention have been illustrated and described, various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims and larger.