A stent graft having improved attachment within a body vessel

IS 2 256 178 T3

DESCRIPTION

Stent-prosthesis with an improved means of attaching a stent to a prosthesis.

Field of the invention

The present invention relates to percutaneously applied stent-prostheses for the repair of abdominal aortic aneurysms.

Background of the invention

An abdominal aortic aneurysm is a sac caused by an abnormal dilation of the wall of the aorta, a main artery in the body, as it passes through the abdomen. The abdomen is the part of the body that is between the thorax and the pelvis. It contains a cavity, known as the abdominal cavity, separated from the thoracic cavity by the diaphragm and lined by a membrane, the peritoneum. The aorta is the main trunk or artery from which the arterial system proceeds. It comes from the left ventricle of the heart, runs upward, curves, and runs down through the chest and through the abdomen to approximately the level of the fourth lumbar vertebra, where it divides into two common iliac arteries.

The aneurysm frequently appears in the infrarenal part of the diseased aorta, for example, below the kidneys. When left untreated, the aneurysm can eventually cause the sac to rupture with consequent fatal bleeding in a very short period of time. The high mortality associated with rupture has led to the present state of the art and transabdominal surgical repair of abdominal aortic aneurysm. However, as surgery involves the abdominal wall it is an important task with great associated risks. There is considerable mortality and morbidity associated with the magnitude of this surgical intervention, which essentially involves the replacement of the diseased and aneurysmic segment of the blood vessel with a prosthetic device, typically a tube or prosthesis, typically made of DACRON®, TEFLON®, GORTEX® or other suitable material.

To perform the surgical procedure, it is necessary to expose the aorta through an abdominal incision, which can extend from the rib cage to the pubis. The aorta must be supported transversely both above and below the aneurysm, so that the aneurysm can then be opened and the thrombus or blood clot, and arteriosclerotic debris, can be removed. The small arterial branches emerging from the posterior wall of the aorta are tied off. DACRON tube or prosthesis is sutured in position^® approximately the same size as the normal aorta, thus replacing the aneurysm. Blood flow through the prosthesis is then restored. The intestines need to be displaced in order to reach the back wall of the abdomen before clamping on the aorta.

If the surgery is performed before the rupture of the abdominal aortic aneurysm, the survival rate of the treated patients is markedly higher than if the surgery is performed after the rupture of the aneurysm, although the subsequent mortality is still relatively high. Although abdominal aortic aneurysms can be detected on routine examinations, the patient may not experience any pain from their condition. Therefore, if the patient does not pass routine examinations, the aneurysm may progress to the rupture stage.

The drawbacks associated with conventional prior art surgery, in addition to the high mortality rate, are: the long recovery periods associated with the large surgical exposure in such open procedures; difficulties in suturing the prosthesis, or tube, to the aorta; the loss of existing thrombosis to support and reinforce the prosthesis; the unsuitability of surgery for many patients with abdominal aortic aneurysm; and problems associated with performing emergency surgery after aneurysm rupture. Regarding the duration of recovery, a patient can be expected to spend between 1 and 2 weeks in the hospital after the operation, most of which is spent in the intensive care unit, and a period of convalescence in between 2 and 3 months, especially if the patient has other illnesses such as heart, lung and / or kidney disease, in which case the hospital stay is also prolonged. Since the prosthesis has to be secured or sutured to the remaining part of the aorta, it is often difficult to perform the suturing step because of the thrombosis present in the remaining part of the aorta, and because the remaining part of the wall of the aorta can be friable or easily breakable.

Since in prior art surgery the thrombosis is totally eliminated, the new prosthesis does not have the benefit of the previously existing thrombosis in it, which could be used to support and reinforce the prosthesis, if the prosthesis could be inserted into the prosthesis. existing thrombosis. Since many patients who have abdominal aortic aneurysm also have other chronic conditions, such as heart, lung, liver and / or kidney disease, along with the fact that many of these patients are older, these patients are not ideal candidates for such. surgery, which is considered major surgery. Such patients have difficulty surviving the operation. Finally, once the aneurysm has ruptured, it is difficult to perform conventional surgery expeditiously because of the extent of the surgery.

Consequently, the prior art teaches various procedures and apparatus for repairing an abdominal aortic aneurysm that are estimated to reduce subsequent mortality and morbidity requiring both an abdominal incision and general anesthesia, without requiring suturing of the prosthesis to the remaining aortic wall. , and that allows to retain the aortic wall and the existing thrombosis in it to reinforce and support the aortic prosthesis. An example of such a method and apparatus is disclosed in US Patents 5,316,023 issued to Palmaz et al. On May 31, 1994; 5,360,443 issued to Barone et al. On November 1, 1994; 5,518,071 issued to Parodi on November 26, 1996; and 5,591,229 issued to Parodi on January 1, 1997.

Devices such as that shown in the above referenced Barone patent use an improved procedure to repair an abdominal aortic aneurysm in an aorta that has two iliac arteries associated with it. The device includes first and second tubes, preferably made from a variety of materials such as DACRON^® and other polyester materials, TEFLON^® (polytetrafluoroethylene), DACRON^® coated with TEFLON^®, porous polyurethane, silicone, polytetrafluoroethylene expan2

ES 2 256 178 T3 dido, and expanded polyurethane. It is preferred that all of the above materials are porous to allow an inner shell layer to be formed on the tubes. Each of the tubes is connected to an expandable and deformable tubular member, or stent. These stents can be similar in structure to those described in US patents. 4,733,665, issued March 29, 1988; 4,739,762, issued April 26, 1988; and 4,776,337, issued November 11, 1988, all prior patents being in the name of Julio C. Palmaz. Each of the tube / stent structures is then disposed on the end of a balloon catheter. Either tube is inserted into the same femoral artery of the patient and the other tube is inserted into the other femoral artery or one of the tubes is inserted into a femoral artery of the patient and the other tube is inserted into the other femoral artery of the patient . The tubes are then applied intraluminally to the aorta, placing at least part of each tube within the abdominal aortic aneurysm. The balloons on the distal ends of the catheters then expand and deform the tubular members, to force the tubular members radially outward into contact with the aorta and each other. This secures the tubular members and at least part of each tube within the aorta, whereby the tubes offer a bilateral fluid conduit through the abdominal aortic aneurysm.

While the aforementioned devices seem to work well, there is a desire to improve the device. More specifically, there was a need for most of the blood through the abdomen to flow through the bilateral fluid ducts and not around them where further damage can be caused. The stent precursor stent gasket described in European patent application EP 0947179, filed March 29, 1999, in European patent application EP 1000590 (Al), filed November 8, 1999, and European patent application EP 1066665, limits the amount of blood that could leak around the bilateral fluid conduits and into the aneurysm. The stem of the precursor stent is positioned within the infrarenal neck, between an abdominal aortic aneurysm and the renal arteries of a patient to aid in abdominal aortic aneurysm repair. The stent is designed to be attached to bilateral prostheses to direct blood flow. The prosthesis has a distal end for positioning distal to the aneurysm, and a proximal end for positioning proximal to the aneurysm. The precursor stent sleeve includes a substantially cylindrical expandable member having a proximal end, a distal end, and an interior. The stent sleeve further includes a compressible sleeve member located within and connected to the expandable member. The compressible member is substantially impermeable to blood when in a compressed state and is coupled to the prosthesis. This is how the attached device can direct blood flow through the prosthesis, the gasket member substantially preventing blood from flowing into the aneurysm.

While the devices described above represent great improvements over the prior art, there has been a desire for a better device for connecting the prosthesis material to the prosthesis used in the devices described above. There has been a desire for an improved stent flange member for better connection of the stent flange member to the aortic wall. There has been a desire for a mechanism to ensure that the stent flange member does not prematurely deploy. There has been a desire to improve the design of stents to make them work better. Lastly, there has been a desire to improve prostheses on the same item-prostheses to make them work better during deployment. The invention described below provides such an improved device.

In WO 97/12562, a stent-prosthesis of the type set forth in the preamble of claim 1 appended is disclosed.

Summary of the invention

In accordance with the present invention a stent-prosthesis is provided for insertion into a conduit of the body, such as a blood vessel, in order to repair said conduit. The stent-prosthesis includes a substantially cylindrical hollow extensible stent comprising a plurality of interconnected struts. The stent has a distal end and a proximal end and an interior surface. At least one strut of the stent has first and second openings that extend therethrough from the inner surface to the outer surface. The stent-prosthesis also includes a prosthesis member that covers a predetermined portion of at least one of the interior surface and the exterior surface of the stent. In addition, the stent-prosthesis also includes a clip configured to connect the prosthesis member to the stent. The staple has a crown and two legs extending from it. At least one of the legs of the staple extends through the prosthesis material and through the first opening. Both legs are bent internally towards said crown in such a way that they turn back and extend through the second opening.

Brief description of the drawings

The foregoing and other aspects of the present invention will be better appreciated by reference to the detailed description of the invention in conjunction with the accompanying drawings, in which:

Figure 1 is a perspective view of a precursor stent (shown without the gasket and in an exploded state)

Figure 2 is a view similar to that of Figure 1 but including a flange member.

Figure 3 is a cross-sectional view of the precursor stent of Figure 2 taken along line 3-3 of Figure 2.

Figure 4 is a side elevational view of a stent stent prior to application of the stent material and shown in an enlarged state.

Figure 5 is a side elevation view of a longitudinally pleated prosthesis to be used in conjunction with the stent of Figure 4 in which the pleats are discontinuous.

Figure 6 is a partial side elevation view of another embodiment of the prosthesis in which the longitudinal folds are interrupted by circumferential folds.

Figure 7 is an end elevational view of the prosthesis taken along line 7-7 of the view of Figure 5, the broken line depicting the prosthesis in a compressed state.

Figure 8 is a side elevation view of a complete stent-prosthesis assembly shown in the deployed state.

IS 2 256 178 T3

Figure 9 is an enlarged partial plan view of a connecting tab at the cranial end of the stent as shown in the circled area of ​​Figure 4.

Figure 10 is a partial exploded cross-sectional view of the connecting tab taken along line 10-10 of Figure 9 and includes a clip and a portion of the prosthesis material prior to attaching the prosthesis to the stent .

Figure 11 is a partial cross-sectional view of the connecting means after engaging the staple.

Figure 12 is an enlarged partial plan view of a connection node at the caudal end of the stent as shown in the circled area of ​​Figure 4.

Figure 13 is a partial exploded cross-sectional view of the connection node taken along the section line of Figure 12 and includes a clip and a portion of the prosthesis material prior to attachment of the prosthesis to the stent.

Figure 14 is a partial cross-sectional view of the connecting means after engaging the staple.

Figure 15 is a partial exploded perspective view of the caudal end of the stent, or endoprosthesis, and a portion of the delivery system shown after release from the delivery system.

Figures 16, 17 and 18 are consecutive schematic perspective views showing the procedure of placement and deployment of the stent-prosthesis, or endoprosthesis, after the precursor stent has already been deployed.

Figure 19 is an elevational view of a fully deployed abdominal aortic repair system.

Figure 20 is a top plan view of the precursor stent viewed along line 20-20 of the view of Figure 19.

Figure 21 is a photomicrograph of the gasket material prior to substantial cell ingrowth, taken along line 21-21 of Figure 3.

Figure 22 is a photomicrograph of the gasket material after substantial cellular ingrowth, or biofusion, has occurred taken along line 22-22 of Figure 19.

Figure 23 is an elevational view of a delivery system for a stent dressing, in which the delivery system is inserted into an abdominal aortic aneurysm.

Figure 24 is a view similar to that of the figure but showing the stent sleeve partially deployed from its delivery system.

Figure 25 is a view similar to that of the figure but showing the fully deployed stent sleeve from its delivery system.

Detailed description of the invention

A preferred use of the present invention is the treatment of abdominal aortic aneurysms. A better understanding of the device of the present invention and its use in the treatment of abdominal aortic aneurysms can be achieved by reading the following description in conjunction with the aforementioned references. Furthermore, the terms "cranial" and "distal" will refer to the direction towards the patient's head, and the terms "caudal" or "proximal" will refer to the direction opposite to that of the patient's head.

Referring now to the drawings, in which like numerals indicate the same item in all views, a precursor stent 10 is shown in Figure 1. As will be discussed later, the precursor stent 10 is to be deployed within the infrarenal neck, between an abdominal aortic aneurysm and the renal arteries of a patient to aid in abdominal aortic aneurysm repair. The precursor stent is designed to be attached to one or more stent-grafts to direct blood flow through the aneurysm. The precursor stent includes a substantially cylindrical self-expanding member 12 made of a plurality of interconnected struts. The self-expanding member 12 having two open ends, a proximal end 14 and a distal end 16, and a longitudinal axis extending between said ends and an interior 18. The precursor stent further includes at least two, but preferably 8, as shown in Figure 1, spaced apart longitudinal legs 20 each having proximal and distal ends 24 and 26, respectively. Preferably, there is a leg extending from each vertex 11 of the diamonds 13 (said diamonds being formed by the struts). The distal ends 26 of the legs are connected to the proximal end 14 of the self-expanding member 12, the legs extending proximally away from the self-expanding member. At least one, but preferably each leg, includes a protrusion 28 adjoining its proximal end which, as described in greater detail below, allows the stent to be collected within its delivery apparatus after partial or full deployment of member 12 self-expanding so that it can be returned, or otherwise repositioned for proper alignment.

The self-expanding stents described herein are preferably made of superelastic nickel titanium (Nitinol) alloys. Descriptions of medical devices using such alloys can be found in US Patent 4,665,906, issued to Jervis on May 19, 1987 and in European Patent Application EP 0928606, filed on January 8, 1999. The precursor stent 10 is preferably a tubular piece laser cut from a nickel titanium alloy and therefore treated to exhibit superelastic properties at body temperature. The precursor stent 10 is shown in the figures as a diamond shaped stent, having approximately 8 diamonds, and when the stent is fully expanded the diamonds should have 45-55 degree angles at their distal and proximal ends. However, the precursor stent 10 can take very different shapes or configurations.

In one embodiment of the precursor stent 10, shown in most of the figures but removed from Figure 1 for clarity, the precursor stent 10 further includes a flange member 30 (thus forming a stent or stent-prosthesis flange). This aspect can be better understood by referring to Figures 2 and 3. As noted in those figures, the precursor stent 10 further includes a flange member 30. The gasket member 30 surrounds the self-expanding member 12 and may be located along the interior of the self-expanding member 12, the exterior of the self-expanding member 12, or both. Frisa member helps prevent any blood from flowing around4

ES 2 256 178 T3 of the stent-prostheses, described below, after they have been inserted (as shown in Figure 19) and which can flow around the same precursor stent. In this embodiment the gasket member 30 is a compressible member located along both the inside and the outside of the expandable member 12.

Fringe member 30 can be made from any number of materials known to those of skill in the art. Preferably, the gasket member 30 is made of an open cell polyurethane foam, however other flexible foams could be used, such as polyethylene, polytetrafluoroethylene, other different polymeric materials that are woven or knitted can also be used to provide a structure flexible such as polyurethane, polypropylene, polytetrafluoroethylene. Preferably, the polyurethane foam has a cell size of 50-100 pores per 25.4 mm (inch), and the density of the foam is 24.3 - 56.02 kg / m³ (1.5 - 3.5 lb / ft³). Foams that have these qualities absorb blood like a sponge, contributing to stagnation of blood which leads to thrombosis. In addition, they provide a lattice for cellular infiltration, and over time obstruct the uptake of tissue. This helps to better anchor the device within the body, thereby preventing migration of the stent. An example of such a foam is shown in the photograph in Figure 21. Figure 21 shows an electron microscope scan of an open cell polyurethane foam having approximately 200-500 micron pores.

This ability of the artery wall tissue to incorporate the open pore foam structure has been termed by the beneficiary "Biofusion". This tissue incorporation effect can be better understood by referring to the photographs in Figures 21 and 22. Figure 22 shows histological photographs of connective tissue infiltrating and re-engendering in the frisa member 30 one month after implantation of a device in a target glass. This ability of the tissue to re-engender in the foam creates a long-term stable biological interface that, at approximately six weeks after implantation, cannot be separated from the tissue without breaking the foam material. The “Biofusion” effect has many benefits. It has the potential to prevent subsequent endofiltration by preventing areas of unorganized coagulation from dislodging or recanalizing. It is also estimated that "Biofusion" creates a collar of connective tissue around the frieze that could prevent the aortic neck from dilating over time. The restriction of neck dilation prevents endofiltration pathways and implant migration that could be caused by insufficient fit with the aorta. The use of the types of foams previously described in stent-prostheses is not limited to the repair of abdominal aortic aneurysms, but could be applied in many applications of the stent-prosthesis such as the repair of other aneurysms and the malformation and occlusion of cups.

The foams described above are preferably highly compressible, to keep the gathering profile low for better application. Furthermore, it is preferable that the fringe member is substantially impermeable to the flow of blood, at least when in a partially compressed state. When used for the present stent-prosthesis materials that are substantially impermeable to blood flow include materials that become substantially impermeable to blood flow after saturation with blood. When stent tubes and prosthesis members, described below, are inserted and expanded within sleeve 30, sleeve 30 is compressed. In this state, the sleeve must be substantially impermeable to blood to prevent blood from flow through interior 18 of self-expanding member 12 and into the aneurysm. The gasket 30 may be connected to the expandable self-expanding member 12 by any number of means including polyurethane adhesive, a plurality of conventional polypropylene sutures, DACRON^® or any other suitable and connected material. Other methods of connecting the gasket 30 to the expandable member include adhesives, ultrasonic welding, mechanical clamping, and staples.

As seen in Figure 2, the precursor stent 10 includes a number of radiation opaque markers 15. As shown, the markers 15 are coils of radiation opaque metal, wrapped around the struts of the stent. The markers are positioned along the stent so that the clinician can better know the exact position of the stent during deployment when viewed fluoroscopically. Preferably, the markers 15 are made of 0.254 mm (0.010 inch) diameter tantalum (Ta) wire wrapped tightly around the struts. Three markers are used; two near the distal end of the device and one proximal to it. The two distals are 180 ° apart and the proximal one is equally spaced between the two distals when viewed in rotation where the top two are as far apart as possible. This proximal marker then aids in the correct rotational positioning of the device. Specifically, one of the distal markers is 5mm long and is contiguous with the opening 34 of the gasket; the other is 2 mm long and is contiguous with hole 36. Since hole 36 must be located adjacent to the right side of the aneurysm, as shown in Figure 19, the small distal marking should be located on the right side; the proximal marker (also 2mm long) should be made present fluoroscopically midway between the two top markers.

As seen in Figures 2 and 3, the precursor stent further includes an occlusive member 32 connected to the self-expanding member 12. The occlusive member covers at least a portion of the interior of the expandable member. The occlusive member covers the interior of member 12 such that an opening 5 in the expandable member that provides a conduit from its proximal end 14 to its distal end 16 is at least partially blocked. Occlusive member 32 further includes two openings 34 and 36 extending therethrough. The opening 34 is relatively small and is designed to receive a guidewire in which the guidewire helps to apply the precursor stent 10 to the target site. Opening 36 is relatively large and is designed to receive another guidewire having a proximal loaded stent-graft therein. As will be explained later, the occlusive member helps to ensure correct placement of the two angled stent-grafts.

The precursor stent 10 acts to temporarily scaffold the sheath member within the body until

ES 2 256 178 T3 that the stent-prostheses are deployed (see figure 19). A preferred embodiment of a stent 40 is shown in Figure 4. Stent 40 is made up of a plurality of interconnected struts 44 and has an inner surface 43A and an outer surface 43B (shown in Figure 15). Figure 4 shows stent 40 in its fully deployed, unfolded state. As those skilled in the art can appreciate, stent 40 must be folded to be less in diameter prior to insertion into a patient. Preferably, the stent 40 is made of Nitinol that is superelastic and has sufficient outward force to remain within the body without the use of the precursor stent 10. Preferably, stent 40 is made from a single Nitinol tube having the following laser-etched physiognomy therein. Stent 40 has a number of rings 42 comprising a number of struts 44 that constitute a diamond-shaped configuration, wherein each ring preferably has 9 diamonds. Stent 40 further includes a number of sinusoidal rings 50 for connecting adjacent rings to each other. Sinusoidal rings are made of a number of alternate struts 52, wherein each ring preferably has 54 struts. As will be explained later in connection with the presentation of Figures 9-14, the stent 40 includes a distal connection means 54 and a proximal connection means 56.

Stent 40 has a proximal ring 48 and a distal ring 46, also called anchors. The proximal ring is widened and exposed once the prosthesis is attached to it. The diamond shape of the anchors, as well as that of the other rings, gives the rings radial and longitudinal rigidity. Longitudinal rigidity allows for better mechanical fixation of stent 40 to a prosthesis (described below). The radial consistency allows the distal ring 46 to better connect and seal to the stent sleeve or precursor stent 10, and allows the proximal ring 48 to better fixation and seal to the arterial wall. In a preferred embodiment, the proximal and distal rings have greater radial and longitudinal consistency than the rings between them. This creates a stent-graft that has rigid anchoring ends, but a more flexible body for navigation through the vascular system. Stiffer ends can be achieved by changing the dimensions of the end ring braces, or by varying the heat treatment of the end rings during fabrication. The rings allow the stent to fit more easily, and generally provide more flexibility when the stent is being delivered through a tortuous vessel. When a non-compliant prosthesis is attached to stent 40, the stiffness of the diamond rings scaffolds the entire prosthesis that folds into the blood flow conduit, while maintaining a tight bend radius.

As noted above, stent 40 preferably has a prosthetic member connected thereto. The graft member covers at least a portion of the interior or exterior of stent 40, and more preferably, substantially covers all of said exterior of stent 40. One embodiment of a tubular graft 60 is shown in Figures 5-7. The prosthetic member 60 can be made of any number of materials known to those skilled in the art, including woven polyester, Dacron, Teflon, or polyurethane. The prosthesis 60 has a proximal end 64, a distal end 62, and a longitudinal axis 66 extending between said ends. As seen in FIG. 5, prosthesis 60 has a plurality of longitudinal folds 68 that extend along its surface, and are generally parallel to longitudinal axis 66. As seen in Figure 7, when the prosthesis 60 collapses around its center, rather than when applied to a patient, the folds of the prosthesis come together as a series of radially oriented regular folds that are compacted together, to minimize wrinkling and other geometric irregularities. Upon subsequent expansion, the prosthesis 60 assumes its natural cylindrical shape, and the folds or folds open evenly and symmetrically.

The pleats provide a more uniform pleat of the prosthesis, which aids in the assembly of the stent-prosthesis (the stent 40 connects to the prosthesis 60 as will be discussed later) to form a relatively low-profile delivery system, and allows a controlled and uniform deployment of the same, in addition, the folds 68 help to facilitate the manufacture of the stent-prosthesis, because they indicate the direction parallel to the longitudinal axis, they allow connection of the stent to the prosthesis along these lines and thus inhibit accidental kinking of the prosthesis relative to the stent after connection. The force required to push the stent-prosthesis out of the delivery system can also be reduced, because only the edges of the folds come into frictional contact with the interior surface of the delivery system. Another benefit of the folds is that the blood tends to coagulate generally uniformly in the depressions of the folds, discouraging the formation of asymmetric or large clots on the surface of the prosthesis, thus reducing the risk of embolism.

In a preferred embodiment, the depths of the folds 68 range from 1.52 mm (0.06 inches) to 1.78 mm (0.07 inches) in a prosthesis having a folded inside diameter of 2.03 mm (0 .08 inches) and a folded outside diameter ranging from 3.33 mm (0.131 inches) to 3.94 mm (0.155 inches. This combination of fold depth and inside and outside diameter produces fold frequencies that generally prevent excessive radial flaps in the prosthesis throughout the diameter range of the device.

As best seen in FIG. 6, the prosthesis 60 preferably includes a plurality of radially oriented pleat interruptions 70. The pleat breaks are substantially circular and are oriented perpendicular to the longitudinal axis 66. Although the aforementioned folds 68 provide uniform folding of the prosthesis, they may tend to increase the propensity for kinking as they run perpendicular to the natural folding tendencies of the prosthesis when flexed along its axis. The pleat interruptions 70 allow the prosthesis to flex better at selective points. This design provides a prosthesis that has good pliability and kink resistance.

Figure 9 shows a close-up view of a distal connection means 54 of the stent. The distal ring 46 of the stent 40 has a plurality of connecting tabs 82 extending therefrom, which are formed from the joining together of two struts 44 (a) and 44 (b). The connecting means 54 comprises two openings 84 (first opening) and 86 (second opening) extending therethrough. As seen in Figure 10, prosthesis 60 preferably also includes

ES 2 256 178 T3 two openings 74 and 76 (which can be created initially during the connection process) that are coincident with the openings 84 and 86 when the prosthesis 60 is placed on the stent 40 for its connection, Finally, the means 54 The connecting leg includes a staple 90 having a crown 92 connecting legs 94 (first leg) and 96 (second leg) extending from the crown. Connecting leg 96 extends through aperture 76 and then through aperture 86. Simultaneously, leg 94 bends around notch 85, but does not pass through prosthesis 60 like leg 96. Then, connecting legs 94 and 96 retract through openings 84 and 74 and into crown 92, to connect the distal end of the prosthesis to the distal end of the stent, as shown in Figure 11. Legs 94 and 96 make contact with crown 92 after connection. Preferably, there are six staples at the distal end.

Figure 12 shows a close-up view of a proximal connection means 56 of stent 40. Proximal ring 48 of stent 40 has a plurality of members 110 that meet at the junction of four struts 44 (c) - 44 (f ). The connecting means 45 comprises three openings, 112 (first opening), 114 (middle opening) and 116 (second opening) extending therethrough. As seen in Figure 13, prosthesis 60 also preferably includes three openings 121, 123, and 125 (which can be made initially during the connection process by drilling through with a staple) that coincide with openings 112, 114 and 116 when prosthesis 60 is positioned on stent 40 for connection. Finally, the connecting means 56 includes a staple 120 having a crown 122 and legs 124 (first leg) and 126 (second leg) extending from the crown. Legs 124 and 126 extend through apertures 112 and 116 and then through apertures 121 and 125 respectively. Legs 124 and 126 are then retracted through openings 124 and 114 and into crown 122. to connect the proximal end of the prosthesis to the proximal end of the stent, as shown in the figure. Legs 124 and 126 contact crown 122 after connection. Preferably, there are three staples at the proximal end.

The design of anterior staple openings has many benefits for connection of a stent to a prosthesis. Because the legs of the staple are bent round and embedded within a cavity or the like, any risk of puncturing an inflation balloon is minimal. Furthermore, it is believed that the structural integrity of the stent-prosthesis is increased because these clips would connect the prosthesis to the stent more securely compared to prior art designs that use suturing or adhesives to connect the prosthesis to the stent. In US 4,627,437, a type of staple is shown having legs that extend through a first and a second hole and retract through an intermediate hole. This disclosure is in the context of the securing of tissue parts. Staples 90 and 120, illustrated in Figure 8, can be made from any number of materials known in the art, including tantalum alloys, platinum alloys, or stainless steel, such as 316 LVM stainless steel. The staples can take other shapes and forms, and can be coated for lubrication purposes. Having staples made of radiation opaque material helps the clinician deploy the device accurately.

Another aspect of the stent-prosthesis 80, illustrated in Figure 8, can be better understood by referring to its delivery apparatus 130 shown in Figure 15. Apparatus 130 is very similar to other self-expanding delivery devices described in the references. previously incorporated. Apparatus 130 includes an outer sheath 132 that is essentially an elongated tubular member, similar to ordinary guiding catheters that are well known to those of skill in the art. An example of an especially preferred outer sheath is described in transferred US Patent 6,019,778, issued February 1, 2000. Sheath 132 has a distal end 134 and a proximal end (not shown). Apparatus 130 also includes an inner element 140 located coaxially within outer sleeve 132 for deployment. The inner shaft has a distal end 142 and a proximal end (not shown). The distal end 142 of the shaft has at least two grooves 144 disposed therein. Stent 40 preferably has a number of projections 41 disposed at its proximal end. The projections of the stent are fixed in the grooves of the inner shaft, whereby the stent is removably connected to the inner shaft. The delivery system of the precursor stent 10 is also similar in that it has an outer sheath and an inner shaft with grooves to receive the projections 28 of the precursor stent 10.

The benefits of the projections 41 of the stent 40 and the projections 28 of the precursor stent 10 and the grooves of the inner shaft of their delivery system are that they can allow partial deployment of the stents and retrieve them within the delivery apparatus if the physician you are not satisfied with the position of the stent. The system allows the physician to partially deploy one of the precursor stents 10 or of the stent-prostheses 80 while the protrusions remain within the sheath. The boss and groove combination allows the clinician to pull the stent into the delivery device if its placement is not optimal.

The benefits of the protrusions 28 of the precursor stent 10 and the grooves of the interior axes of its delivery system can best be described with reference to Figures 23-25. Figure 23 shows an exemplary embodiment of the delivery apparatus 300. stent plate or precursor stent 10. Apparatus 300 is very similar to other self-expanding applicator apparatuses described in the above references. Apparatus 300 includes an outer sheath 332 that is essentially an elongated tubular member, similar to ordinary guiding catheters that are well known to those of skill in the art. An example of an especially preferred outer sleeve is described in transferred US Patent 6,019,778, issued February 1, 2000. Apparatus 300 also includes an inner shaft 340 located coaxially within outer sleeve 332 prior to deployment. The inner shaft 334 includes several grooves 344. As seen in Figure 24, this arrangement allows for partial deployment of the precursor stent 10 and its retrieval in the delivery apparatus if the clinician is not satisfied with the initial position of the stent. The present invention allows the physician to partially deploy the precursor stent 10 while the protrusions remain within the sheath. The combination of projections and grooves allows the clinician to pull the stent into the delivery device if its placement is not optimal.

In order to prevent the doctor from deploying

ES 2 256 178 T3 fully precursor stent 10 prematurely, preferably, a stop 350 is placed on the inner shaft. The stop could be a ring with a diameter greater than that of the sheath so that when the sheath is pulled proximally along the inner axis it collides with the stop, and prevents full deployment of the entire precursor stent 10. The stopper is preferably releasably connected to the inner member so that it is releasable from its engagement on the inner shaft to allow the outer member to slide back enough for full deployment of all of the precursor stent 10 within the body.

Figures 16-18 generally show how the above-described stent-prosthesis is deployed within the body. Before what is shown in Figure 16, the physician must first insert the precursor stent 10, which has the gasket member connected thereto, into the body with the aid of the guide wire 200, which remains in the body after deployment. The stent-prosthesis is applied through one of the patient's femoral arteries and into a first iliac artery 1 and is deployed within the infrarenal neck 3. The delivery device is then removed from the precursor stent10 without removing the guidewire 200, and another guidewire 202 is inserted through the other femoral artery and into the other iliac artery 2. Because the opening 36 of the occlusive member 32 is relatively large, the clinician can only maneuver the guidewire 202 through it. Stent-graft delivery devices 130 (a) and 130 (b) are then inserted into femoral arteries 1 and 2 by sliding along guidewires 200 and 202, and precisely applied to the target site. Next, both stent-grafts 80 (a) and 8 (b) are deployed within the body either separately or simultaneously. Finally, the distal ends of the stent-grafts reside level with each other, just below the renal arteries, and somewhat above the distal end of the stent sleeve. The stent-prosthesis bodies pass through the stent sleeve through the aneurysm sac.

After proper application, the precursor stent 10 and stent-grafts 80 (a) and 80 (b) should appear as shown in Figure 19. The precursor stent 10 along with its connected flange member 30 are firmly secured within the neck 3 infrarenal. The outward force of the stent-grafts 80 on the precursor stent 10 helps to secure the device within the body. The proximal ends of the stent grafts are firmly connected to iliac arteries 1 and 2. Thereafter, blood will flow from abdominal aorta 302 descending towards and through stent grafts 80 (a) and 80 (b) and towards iliac arteries 1 and 2, bypassing aneurysmic sac 304 and all components are precisely positioned, the The distal end of the device should be shown as in Figure 20.

In order to prevent the physician from fully deploying the precursor stent 10 prematurely, preferably, a releasable stop is placed on the inner shaft. The stopper could be a ring with a diameter greater than that of the outer member, such that when the outer member is pulled proximally along the inner axis it collides with the stopper and prevents full deployment of the entire precursor stent 10. Preferably, the stopper is releasably connected to the inner member by threads, snap fit or the like, so that it can be released from engagement with the inner shaft to allow the outer member to slide back enough to fully deploy all. the precursor stent 10 within the body.

Although specific embodiments of the present invention have been shown, modifications can be made to the device and / or method without departing from the scope of the present invention. The terms used in describing the invention are used in a descriptive sense and not as limiting terms.