WO2016160540A1

WO2016160540A1 - Improved endografts for endovascular repair of abdominal aortic aneurysms

Info

Publication number: WO2016160540A1
Application number: PCT/US2016/024136
Authority: WO
Inventors: Hugh TROUT
Original assignee: Eva Corporation
Priority date: 2015-03-27
Filing date: 2016-03-25
Publication date: 2016-10-06

Abstract

In one aspect, an endograft for the endovascular repair of an abdominal aorta having an aortic aneurysm and an aortic neck may generally include a moderately supported graft body extending lengthwise between a proximal end and a distal end. The graft body may include a proximal tube portion and first and second distal limbs. The proximal tube portion may extend lengthwise between the proximal end of the graft body and the first and second distal limbs. The first and second distal limbs may extend lengthwise between the proximal tube portion and the distal end of the graft body. The proximal tube portion may include a stented section having a stent configured to provide structural support to the proximal tube portion. In addition, each of the first and second distal limbs may correspond to non-stented portions of the graft body.

Description

IMPROVED ENDOGRAFTS FOR ENDOVASCULAR REPAIR

OF ABDOMINAL AORTIC ANEURYSMS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is based upon and claims priority to U.S. Provisional Patent Application No. 62/139,079 filed on March 27, 2015, the disclosure of which is hereby incorporated by reference herein in its entirety for all purposes.

FIELD OF THE INVENTION

[0002] The present subject matter relates generally improved endograft designs and related systems and methods for the endovascular repair of abdominal aortic aneurysms.

BACKGROUND OF THE INVENTION

[0003] An aneurysm is a ballooning of the wall of an artery resulting from the weakening of the artery due to disease or other conditions. Left untreated, the aneurysm will frequently rupture, resulting in loss of blood through the rupture and death.

[0004] Aortic aneurysms are the most common form of arterial aneurysm and are life threatening. The aorta is the main artery which supplies blood to the circulatory system. The aorta arises from the left ventricle of the heart, passes upward and bends over behind the heart, and passes down through the thorax and abdomen. Among other arterial vessels branching off the aorta along its path, the abdominal aorta supplies two side vessels to the kidneys, the renal arteries.

Below the level of the renal arteries, the abdominal aorta continues to about the level of the fourth lumbar vertebrae (or the navel), where it divides into the iliac arteries. The iliac arteries, in turn, supply blood to the lower extremities and the perineal region.

[0005] It is common for an aortic aneurysm to occur in the portion of the abdominal aorta between the renal arteries and the iliac arteries. This portion of the abdominal aorta is particularly susceptible to weakening, resulting in an aortic aneurysm. Such an aneurysm is often located near the iliac arteries. An aortic aneurysm larger than about 5 cm in diameter in this section of the aorta is ominous. Left untreated, the aneurysm may rupture, resulting in rapid, and usually fatal, hemorrhaging. Typically, a surgical procedure is not performed on

abdominal aortic aneurysms smaller than 5 centimeters as no statistical benefit exists to do so.

[0006] Aneurysms in the abdominal aorta are associated with a particularly high mortality rate; accordingly, current medical standards call for urgent operative repair. Abdominal surgery, however, results in substantial stress to the body. Although the mortality rate for an aortic aneurysm is extremely high, there is also considerable mortality and morbidity associated with open surgical intervention to repair an aortic aneurysm. This intervention involves penetrating the abdominal wall to the location of the aneurysm to reinforce or replace the diseased section of the abdominal wall (i.e., abdominal aorta). A prosthetic device, typically a synthetic tube graft, is used for this purpose. The graft serves to exclude the aneurysm from the circulatory system, thus relieving pressure and stress on the weakened section of the aorta at the aneurysm.

[0007] Repair of an aortic aneurysm by surgical means is a major operative procedure. Substantial morbidity accompanies the procedure, resulting in a protracted recovery period. Further, the procedure entails a substantial risk of mortality. While surgical intervention may be indicated and the surgery carries attendant risk, certain patients may not be able to tolerate the stress of intraabdominal surgery. It is, therefore, desirable to reduce the mortality and morbidity associated with intra-abdominal surgical intervention.

[0008] In recent years, methods have been developed to attempt to treat an abdominal aortic aneurysm without the attendant risks of intra-abdominal surgical intervention. For example, endovascular repair methods have been developed that utilize a fully stented or fully supported endograft. The endograft is inserted through the external iliac artery and into the right and/or left common iliac artery. The proximal portion of the fully supported endograft is attached to the un-dilated portion of the aorta (e.g., often referred to as the aortic neck). The distal portion(s) of the fully supported endograft are attached to the right and left common iliac arteries such that the endograft bridges the aneurysm.

[0009] While fully supported endografts provide a means for treatment of abdominal aortic aneurysms, such endografts often lead to complications in the long term. For example, fully supported endografts exhibit significant columnar rigidity. While such rigidity may allow for a reduction of the migration of the endograft, the rigidity also prevents the endograft from adapting to changes in the aneurysm conformation, which, over time, can lead to failure of the endograft. In addition, fully supported endografts are often quite expensive to manufacture.

[0010] Accordingly, an improved endograft design that addresses one or more of the issues associated with fully supported endografts would be welcomed in the technology.

BRIEF DESCRIPTION OF THE INVENTION

[0011] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0012] In several embodiments of the present subject matter, an endograft is disclosed for the endovascular repair of an abdominal aorta having an aortic aneurysm and an aortic neck. The endograft may generally include a moderately supported graft body extending lengthwise between a proximal end and a distal end. The graft body may include a proximal tube portion and first and second distal limbs. The proximal tube portion may extend lengthwise between the proximal end of the graft body and the first and second distal limbs. The first and second distal limbs may extend lengthwise between the proximal tube portion and the distal end of the graft body. The proximal tube portion may include a stented section having a stent configured to provide structural support to the proximal tube portion. In addition, each of the first and second distal limbs may correspond to non-stented portions of the graft body.

[0013] In this aspect of the present subject matter, at least a portion of the proximal tube portion may be configured to be secured to the aortic neck and the distal end of the graft body may be configured to be positioned within the aortic aneurysm.

[0014] Also in this aspect of the present subject matter, the endograft may include first and second stented grafts. The first stented graft may include a proximal portion configured to be inserted within the first distal limb and a distal portion configured to be received within a first common iliac artery of the abdominal aorta. The second stented graft may include a proximal portion configured to be inserted within the second distal limb and a distal portion configured to be received within a second common iliac artery of the abdominal aorta.

[0015] Further in this aspect of the present subject matter, the endograft may also include first and second buffer sleeves. The first buffer sleeve may be configured to be received within the first distal limb such that the first buffer sleeve is positioned between the proximal portion of the first stented graft and the first distal limb. The second buffer sleeve may be configured to be received within the second distal limb such that the second buffer sleeve is positioned between the proximal portion of the second stented graft and the second distal limb.

[0016] In this aspect of the present subject matter, the first and second buffer sleeves may be non-stented or stented.

[0017] Also in this aspect of the present subject matter, each of the first and second distal limbs may define a non-cylindrical shape along at least a portion of its length.

[0018] Further in this aspect of the present subject matter, a length of the first distal limb may differ from a length of the second distal limb.

[0019] In this aspect of the present subject matter, each of the first and second distal limbs may include a first lengthwise limb section configured to extend within the aortic aneurysm and a second lengthwise limb section configured to extend within a common iliac artery of the aorta.

[0020] Also in this aspect of the present subject matter, the endograft may include first and second stented tube inserts configured to be inserted within the second lengthwise limb sections of the first and second distal limbs.

[0021] Further in this aspect of the present subject matter, a portion of each of the first and second distal limbs may define a material thickness that is greater than a material thickness of another portion of each of the first and second distal limbs

[0022] In this aspect of the present subject matter, the endograft may also include a non-structural location identifier incorporated within or coupled to at least one of the first distal limb or the second distal limb. [0023] Also in this aspect of the present subject matter, the non-structural location identifier may correspond to a radiopaque marker or a radiopaque wire.

[0024] Further in this aspect of the present subject matter, the graft body may be formed from a graft material, wherein each of the first and second distal limbs is formed entirely from the graft material.

[0025] In this aspect of the present subject matter, the graft body may be formed from a graft material having an outer later and an inner layer, with the stent being positioned between the outer and inner layers of the graft material.

[0026] Also in this aspect of the present subject matter, the stented section of the proximal tube portion may be configured to be positioned entirely within the aortic neck.

[0027] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

[0029] FIG. 1 illustrates a schematic view of an abdominal aorta and its major branches;

[0030] FIG. 2 illustrates a schematic view of the abdominal aorta shown in FIG. 1 having an infrarenal abdominal aortic aneurysm;

[0031] FIG. 3 illustrates a schematic view of one embodiment of a moderately supported graft body that may be used to form all or part of an endograft for the endovascular repair of abdominal aortic aneurysms in accordance with aspects of the present subject matter;

[0032] FIG. 4 illustrates a cross-sectional view of a portion of the moderately supported graft body shown in FIG. 3 taken about line 4-4; [0033] FIG. 5 illustrates the moderately supported graft body shown in FIG. 3 installed within the aorta shown in FIG. 2 relative to the infrarenal abdominal aortic aneurysm in accordance with aspects of the present subject matter;

[0034] FIG. 6 illustrates a schematic view of one embodiment of a three- piece endograft partially installed within the aorta shown in FIG. 2 relative to the infrarenal abdominal aortic aneurysm in accordance with aspects of the present subject matter; , particularly illustrating the endograft including the moderately supported graft body shown in FIG. 3 and first and second stented grafts configured to be coupled between the graft body and the common iliac arteries of the aorta;

[0035] FIG. 7 illustrates another schematic view of the endograft shown in FIG. 6, particularly illustrating both stented grafts being installed relative to the graft body;

[0036] FIG. 8 illustrates a variation of the embodiment of the three- piece endograft shown in FIG. 6 in accordance with aspects of the present subject matter, particularly illustrating the moderately supported graft body including modified distal limbs;

[0037] FIG. 9 illustrates a schematic view of one embodiment of a five- piece endograft partially installed within the aorta shown in FIG. 2 relative to the infrarenal abdominal aortic aneurysm in accordance with aspects of the present subject matter, particularly illustrating the endograft including the moderately supported graft body shown in FIG. 3, first and second buffer sleeves configured to be received within distal limbs of the graft body, and first and second stented grafts configured to be coupled between the distal limbs and the common iliac arteries of the aorta;

[0038] FIG. 10 illustrates another schematic view of the endograft shown in FIG. 9, particularly illustrating both buffer sleeves and both stented grafts being installed relative to the graft body;

[0039] FIG. 1 1 illustrates a schematic view of another embodiment of a moderately supported graft body that may be used to form all or part of an endograft for the endovascular repair of abdominal aortic aneurysms in

accordance with aspects of the present subject matter, particularly illustrating the graft body including distal limbs defining non-cylindrical shapes; [0040] FIG. 12 illustrates another schematic view of the moderately supported graft body shown in FIG. 1 1 with corresponding stented grafts configured to be received within the distal limbs of the graft body;

[0041] FIG. 13 illustrates a schematic view of a further embodiment of a moderately supported graft body that may be used to form all or part of an endograft for the endovascular repair of abdominal aortic aneurysms in accordance with aspects of the present subject matter, particularly illustrating the graft body including distal limbs of varying lengths;

[0042] FIG. 14 illustrates a schematic view of another embodiment of a three- piece endograft partially installed within the aorta shown in FIG. 2 relative to the infrarenal abdominal aortic aneurysm in accordance with aspects of the present subject matter, particularly illustrating the endograft including a moderately supported graft body configured to extend between the aortic neck and the common iliac arteries of the aorta and first and second stented tube inserts configured to be received within distal limbs of the graft body;

[0043] FIG. 15 illustrates another schematic view of the endograft shown in FIG. 14, particularly illustrating both stented tube inserts being installed relative to the graft body; and

[0044] FIG 16 illustrates another schematic view of the moderately supported graft body shown FIG. 3, particularly illustrating the graft body including nonstructural location identifiers incorporated within or coupled to the distal limbs of the graft body.

DETAILED DESCRIPTION OF THE INVENTION

[0045] Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0046] The following definitions generally apply to the description provided herein. It should be appreciated that the definitions are not intended to limit the scope of the inventions described herein, but, rather, are simply intended to provide a general understanding of the meaning of certain terms. The term

"moderately supported endograft" generally refers to an endograft that has metal struts or other support structure over a portion of its length, but not over its entire length. A moderately supported endograft differs from a "fully supported

endograft," which refers to an endograft that has metal struts or other support structure over the entire length of the graft. Additionally, the terms "proximal" and "distal" are used describe a relationship within the body relative to the heart, with the term "proximal" describing a closer position relative to the heart than the term "distal." For instance, the knee is proximal to the foot but distal to the hip.

[0047] In general, the present subject matter is directed to an endograft including a moderately supported graft body for use with the endovascular repair of abdominal aortic aneurysms. Specifically, in several embodiments, the graft body may include a proximal tube portion configured to be secured to an aortic neck located proximal to the aneurysm and first and second distal limbs located distal to the proximal tube portion. In accordance with aspects of the present subject matter, the proximal tube portion may include a stented section having a stent configured to provide structural support for the proximal tube portion. In contrast, the first and second distal limbs may be fully unsupported. For example, the first and second distal limbs may be non-stented or otherwise devoid of stents and other structural components. Such unsupported distal limbs may increase the capability of the endograft to adapt to changes in the aneurysm conformation (e.g., when the aortic neck becomes angulated or the aneurysm shrinks longitudinally after being bypassed with an endograft). In addition, the non-stented distal limbs may be less expensive to manufacture as compared to conventional fully stented limbs.

[0048] Referring now to the drawings, FIG. 1 illustrates a schematic view of an abdominal aorta 20 and its major branches. As shown, the aorta 20 includes a suprarenal aorta portion 22, which corresponds to the portion of the aorta 20 that is superior to or proximal to the left and right renal arteries 24, 26. Additionally, the aorta 20 includes an infrarenal aorta portion 28, which corresponds to the portion of the aorta 20 that begins just inferior to the lower or more distal renal artery 24, 26 and extends to the bifurcation of the aorta 20. A distal portion of the abdominal aorta divides into a left common iliac artery 30 and a right common iliac artery 32. The right common iliac artery 32, in turn, divides into a right external iliac artery 34, which supplies blood flow to the right lower extremity, and a right internal iliac artery 36, which supplies arterial blood flow to the organs of the pelvis. Similarly, the left common iliac artery 30 divides into a left external iliac artery 38 and a left internal iliac artery 40, which supply blood flow to the left lower extremity and left pelvis, respectively. Additionally, as shown in FIG. 1 , the aorta 20 includes small paired lumbar arteries 42 arising from the posterior portion of the infrarenal aorta portion 28 as well as an inferior mesenteric artery 44 arising from the left anteriorolateral portion of the infrarenal aorta portion 28. Moreover, orifices for the celiac artery 46 and the superior mesenteric artery 48 arise from the posterior portion of the suprarenal aorta portion 22.

[0049] It should be appreciated that, for purposes of clarity, further illustrations of the aorta 20 provided herein will not show the suprarenal vessels (e.g. , the celiac artery 46 and the superior mesenteric artery 48), the paired lumbar arteries 42, or the inferior mesenteric artery 44.

[0050] Referring now to FIG. 2, a schematic view of the abdominal aorta 20 described above with an infrarenal abdominal aortic aneurysm 50 is illustrated in accordance with aspects of the present subject matter. As shown, the aneurysm 50 corresponds to a localized section of the infrarenal aorta portion 28 that is enlarged. Additionally, as shown in FIG. 2, when the aneurysm 50 is present, the infrarenal aorta portion 28 may also include an aortic neck 52, which generally corresponds to the non-dilated segment of the infrarenal aorta portion 28 extending between the renal arteries 24, 26 and the aneurysm 50.

[0051] Referring now to FIG. 3, a schematic view of one embodiment of a moderately supported graft body 102 that may be used to form all or part of an endograft 100 for repairing an infrarenal abdominal aortic aneurysm 50 is illustrated in accordance with aspects of the present subject matter. As shown, the graft body 102 is generally formed from a suitable graft material 104 and extends lengthwise between a proximal end 106 and a distal end(s) 108. In general, the graft body 102 may include a proximal tube portion 1 10 and two distal Iimbs1 12, 1 14 (e.g. , a first distal limb 1 12 and a second distal limb 1 14), with the proximal tube portion 1 10 extending lengthwise from the proximal end 106 of the body 102 to the distal limbs 1 12, 1 14 and the distal limbs 1 12, 1 14 extending lengthwise from the proximal tube portion 1 10 to the distal end(s) 108 of the body 102.

[0052] In accordance with aspects of the present subject matter, all or a portion of the proximal tube portion 1 10 of the graft body 102 may be stented or otherwise supported. For example, the graft body 102 may include a stent 1 16 extending along all or a portion of the lengthwise distance defined by the proximal tube portion 1 10 between the proximal end 106 of the body 102 and the distal limbs 1 12, 1 14. In general, the stent 1 16 may correspond to any suitable structure that provides support for the graft material 104 and/or provides a means for securing the proximal tube portion 1 10 to the aortic neck 50. For example, in one embodiment, the stent 1 16 may correspond to a metallic stent forming a scaffolding-type structure that defines a diamond or zigzag pattern. However, in other embodiments, the stent 1 16 may be formed from any other suitable material and/or may define any other suitable pattern that allows the stent 1 16 to provide structural support to the proximal tube portion 1 10 of the graft body 102.

Additionally, the stent 1 16 may be installed at any suitable location relative to the graft material 104. For instance, in one embodiment, the stent 1 16 may be sewn onto the inside of the graft material 104. In other embodiments, the stent 1 16 may be sewn onto the outside of the graft material 104 or placed between two layers of the graft material 104. For instance, FIG. 4 illustrates an example cross-sectional view of a portion of the graft body 102 shown in FIG. 3 taken about line 4-4. As shown, the graft material 104 includes both a first or outer layer 1 18 and a second or inner layer 120. In such an embodiment, the stent 1 16 may be positioned between the inner and outer layers 1 18, 120 of the graft material 104.

[0053] Referring back to FIG. 3, unlike the stented proximal tube portion 1 10, the distal limbs 1 12, 1 14 of the graft body 102 may be completely unsupported or non-stented. For example, the distal limbs 1 12, 1 14 may be completely devoid of stents or other support structure. In such instance, the distal limbs 1 12, 1 14 may, for example, be formed entirely from the graft material 104. However, as will be described below, additional non-support-related components, such as one or more location identifiers 201 , 202, may also be incorporated into the distal limbs 1 12, 1 14.

[0054] It should be appreciated that the graft material 104 may generally correspond to any suitable material known in the art. For example, in one embodiment, the graft material 104 may correspond to a woven polyester material (e.g. , DACRON). In another embodiment, the graft material 104 may be polytetraflouroethylene (PTFE) or any other suitable material.

[0055] Referring now to FIG. 4, a schematic view of one embodiment of the graft body 102 described above installed relative to the aortic aneurysm 50 shown in FIG. 2 is illustrated in accordance with aspects of the present subject matter. As shown, the proximal tube portion 1 10 of the graft body 102 may include a first lengthwise tube section 122 positioned within the aortic neck 52 and a second lengthwise tube section 124 inferior to the aortic neck 52 that extends between the first lengthwise section 122 and the distal limbs 1 12, 1 14. Additionally, each distal limb 1 12, 1 14 may generally be configured to extend within the aortic aneurysm 52 from the second lengthwise tube section 124 of the proximal tube portion 1 10 to the distal end(s) 108 of the graft body 102. As will be described below, in one embodiment, a separate graft component(s) (e.g. , a stented tube or stent-graft and/or a buffer sleeve) may be coupled to the end 108 of each distal limb 1 12, 1 14 to bridge the gap between the distal limb 1 12, 1 14 and the adjacent common iliac artery 30, 32.

[0056] It should be appreciated that the first lengthwise tube section 122 of the proximal tube portion 1 10 may be configured to be attached to the aortic neck 52 using any suitable attachment means known in the art. For instance, the first lengthwise tube section 122 may be attached to the aortic neck using fasteners

126 or any other suitable attachment means, such as sutures, staples, hooks, and/or the like. Example methods and/or fasteners for attaching the first lengthwise tube section 122 of the proximal tube portion 1 10 to the aortic neck 52 are described, for instance, in U.S. Pat. Nos. 5,957,940; 5,997,556; 6,248, 1 18;

6,520,974; and 6,635,066, the disclosures of all of which are hereby incorporated by reference herein in their entirety for all purposes. Additionally, it should be appreciated that, in one embodiment, the diameter of the first lengthwise tube section 122 of the proximal tube portion 1 10 may be oversized relative to the diameter of the aortic neck 52 to provide greater frictional attachment and, thus, enhanced sealing between the graft body 102 and the aortic neck 52.

[0057] It should also be appreciated that, in several embodiments, the first lengthwise tube section 122 of the proximal tube portion 1 10 may be longer than the second lengthwise portion 124 of the proximal tube portion 1 10. For instance, in one embodiment, the first lengthwise tube section 122 may have a length 128 ranging from about 8 millimeters (mm) to about 12 mm, such as from about 9 mm to about 1 1 mm or from about 9.5 mm to about 10.5 mm, while the second lengthwise tube section 124 may have a length 130 ranging from about 0.5 mm to about 3.5 mm, such as from about 1 mm to about 3 mm or from about 1 .5 mm to about 2.5 mm.

[0058] As shown in FIG. 4, in one embodiment, the stent 1 16 may be

configured to be positioned entirely within the first lengthwise tube section 122 of the proximal tube portion 1 10. In such an embodiment, the stent 1 16 may extend lengthwise along all or only a portion of the first lengthwise tube section 122 so that the stent 1 16 is positioned within the aortic neck 52. However, in alternative embodiments, a portion of the stent 1 16 may also be disposed within the second lengthwise tube section 124 of the proximal tube section 1 10 extending inferior or distal to the aortic neck 52.

[0059] Referring now to FIGS. 6 and 7, a schematic view of one embodiment of a three-piece endograft 100 installed relative to the aortic aneurysm 50 shown in FIG. 2 is illustrated in accordance with aspects of the present subject matter. As shown, the endograft 100 includes the graft body 102 described above with reference to FIGS. 3-5. In addition, the endograft 100 includes first and second stented grafts 140, 142 configured to extend between the distal limbs 1 12, 1 14 of the graft body 102 and the common iliac arteries 30,32 such that the endograft 100 bridges the aneurysm between the aortic neck 52 and the common iliac arteries 30, 32. For purposes of illustration, FIG. 6 illustrates one of the stented grafts 140, 142 (e.g., the first stented graft 140) installed relative to the graft body 102 while the other stented graft 140, 142 (e.g., the second stented graft 142) is shown separate from the graft body 102. Additionally, FIG. 7 illustrates both of the stented grafts 140, 142 installed relative to the graft body 102. [0060] As particularly shown in FIG. 6, the stented grafts 140, 142 may correspond to separate components from the graft body 102. In general, each stent graft 140, 142 may be configured as an elongated tube formed from a suitable graft material 144 that extends lengthwise between a first end 146 and a second end 148. Additionally, as shown in the illustrated embodiment, each stented graft 140, 142 may be fully supported between its first and second ends 146, 148. For example, a stent(s) 150 may be provided between the first and second ends 146, 148 of each stented graft 140, 142 to provide structural support to the graft 140, 142.

[0061] Moreover, as shown in FIGS. 6 and 7, the stented grafts 140, 142 may be installed relative to the graft body 102 and the aorta 20 such that a proximal portion 152 of each stented graft 140, 142 is received within and secured to one of the distal limbs 1 12, 1 14 and a distal portion 154 of each stented graft 140, 142 is received within and secured to one of the common iliac arteries 30, 32. In such an embodiment, an intermediate portion 156 of each stented graft 140, 142 may be provided between the proximal and distal portions 152, 154 such that the proximal portion 152 of each stented graft 140, 142 extends lengthwise between the first end 146 of the stented graft 140, 142 and the intermediate portion 156 and the distal portion 154 of each stented graft 140, 142 extends lengthwise between the intermediate portion 156 and the second end 148 of the stented graft 140, 142. As such, the stented grafts 140, 142 may serve to bridge the gap between the graft body 102 and the common iliac arteries 30, 32. It should be appreciated that, in one embodiment, the diameter of the proximal portion 152 of the stented grafts 140, 142 may be oversized relative to the diameter of the distal limbs 1 12, 1 14 to provide greater frictional attachment between the stented grafts 140, 142 and the distal limbs 1 12, 1 14.

[0062] Additionally, when coupling the stented grafts 140, 142 directly to the distal limb 1 12, 1 14, it may be desirable, in certain embodiments, to modify all or a portion of the distal limbs 1 12, 1 14 to provide a means for enhancing or

strengthening the connection between the graft body 102 and the stented grafts 140, 142. For example, FIG. 8 illustrates an embodiment of the endograft 100 shown in FIG. 6 in which the graft material 104 used to form lower portions of the distal limbs 1 12, 1 15 has been modified. For purposes of illustration, FIG. 8 illustrates a partial cross-sectional view of a portion of one of the distal limbs 1 12 (e.g. , the second distal limb 1 14).

[0063] As shown in FIG. 8, in one embodiment, the graft material 104 may be modified by increasing the thickness of the material 104 along the lower portions 158 of the distal limbs 1 12, 1 14. Specifically, as shown in FIG. 8, the graft material 104 forming the lower portions 158 of the distal limbs 1 12, 1 14 (or the graft material 104 forming all of the distal limbs 1 12, 1 14) may have a material thickness 160 that is greater than the material thickness 162 of the remainder of the graft body 102. Alternatively, the graft material 104 may be modified by adjusting its composition relative to the remainder of the graft body 102. For example, in one embodiment, the lower portions 158 of the distal limbs 1 12, 1 14 (or the entirety of the distal limbs 1 12, 1 14) may be formed from a graft material 104 that differs from the graft material 104 used to form the remainder of the graft body 102. In another embodiment, the graft material 104 may be consistent throughout the graft body 102 but the lower portions 158 of the distal limbs 1 12, 1 14 (or the entirety of the distal limbs 1 12, 1 14) may incorporate stronger fibers relative to the fibers used throughout the remainder of the graft body 102. In yet another embodiment, the inner surface of the distal limbs 1 12, 1 14 may be modified to include one or more components and/or features designed to facilitate securing the stented grafts 140, 142 to the distal limbs 1 12, 1 13, such as configuring the inner surface to include hooks or loops (e.g. , a Velcro-like substance), glue (e.g. , typical glue or glue that is temperature activated or activated using another energy source), barbs and/or any other suitable features.

[0064] As opposed to coupling the stented grafts 140, 142 directly to the distal limbs 1 12, 1 14, the endograft 100 may also include a buffer sleeve positioned within each distal limb 1 12, 1 14 to provide a "buffer layer" between the graft body

102 and the stented tubes 140, 142. For example, FIGS. 9 and 10 illustrates an embodiment of the endograft 100 shown in FIGS. 6 and 7 that includes first and second buffer sleeves 170, 172 configured to be positioned between each distal limb 1 12, 1 14 and the adjacent stented graft 140, 142. For purposes of illustration,

FIG. 9 illustrates one of the buffer sleeves 170, 172 (e.g. , the first buffer sleeve

170) installed relative to the graft body 102 and the other buffer sleeve 170, 172

(e.g. , the second buffer sleeve 172) separated from the graft body 102, with both of the stented grafts 140, 142 being separated from the graft body 102.

Additionally, FIG. 10 illustrates the buffer sleeves 170, 172 and the stented grafts 140, 142 installed relative to the graft body 102.

[0065] Similar to the stented grafts 140, 142, the buffer sleeves 170, 172 may correspond to separate components from the graft body 102. As shown, each buffer sleeve 170, 172 may be configured to be installed within one of the distal limbs 1 12, 1 14 such that the buffer sleeve 17p, 172 is at least partially received within the corresponding distal limb 1 12, 1 14. For instance, as shown in FIG. 9, each buffer sleeve 170, 172 may include a proximal portion 174 received within its respective distal limb 1 12, 1 14 and a distal portion 176 extending outwardly from the distal end 108 of the distal limb 1 12, 1 14. Alternatively, each buffer sleeve 170, 172 may be configured to be installed within the graft body 102 such that the entire sleeve 170, 172 is positioned within its respective distal limb 1 12, 1 14.

[0066] In the embodiment shown in FIGS. 9 and 10, the stented grafts 140, 142 may generally be installed relative to the graft body 102 and the aorta 20 similar to that described above with reference to FIGS. 6 and 7. For example, the proximal portion 152 of each stented graft 140, 142 may be received within one of the distal limbs 1 12, 1 14 and the distal portion 154 of each stented graft 140, 142 may be received within of the common iliac arteries 30, 32. However, as shown in FIG. 10, unlike the embodiment described above, the proximal portion 152 of each stented graft 140, 142 may be received directly within the adjacent buffer sleeve 170, 172 such that the buffer sleeves 170, 172 are positioned between the stented grafts 140, 142 and the corresponding distal limbs 1 12, 1 14.

[0067] It should be appreciated that the buffer sleeves 170, 172 may have any suitable configuration and/or may be formed from any suitable material. For example, the buffer sleeves 170, 172 may be composed of any combination of graft material, fabric, stents, and/or barbs. In one embodiment, each buffer sleeve

170, 172 may be provided with hooks or loops (e.g. , a VELCRO-like substance) on its outer surface that matches corresponding hooks or loops on the inner surface of the graft limbs 1 12, 1 14. In another embodiment, each buffer sleeve 170, 172 may correspond to a stented graft having barbs along its exterior such that, when the sleeve 170, 172 is dilated against its respective distal limb 1 12, 1 14, the barbs completely or partially penetrate through the wall(s) of the distal limb 1 12, 1 14. Alternatively, the barbs may be provided on the stented graft 140, 142 such that the barbs penetrate at least partially through the adjacent buffer sleeve 170, 172 and/or the corresponding portion of the distal limb 1 12, 1 14. In a further embodiment, the buffer sleeves 170, 172 may be formed from the same graft material 104 as the graft body 102 such that the portions of the distal limbs 1 12, 14 within which each buffer sleeve 170, 172 is installed define increased material thicknesses.

[0068] It should be appreciated that the distal limbs 1 12, 1 14 of the graft body 102 may generally be configured to define any suitable shape. For instance, as described above with reference FIGS. 3-10, the distal limbs 1 12, 1 14 are generally cylindrically shaped along their length. However, in other embodiments, the distal limbs 1 12, 1 14 may have any other suitable shape. For instance, FIGS. 1 1 and 12 illustrate an embodiment of the graft body 102 in which the distal limbs 1 12, 1 14 define a non-cylindrical lengthwise shape. Specifically, as shown FIG. 1 1 , each distal limb 1 12, 1 14 includes both a diverging lengthwise section 180 along which the diameter of the distal limb 1 12, 1 14 increases as the limb 1 12, 1 14 extends away from the proximal tube portion 1 10 towards the distal end(s) 108 of the graft body 102 and a converging lengthwise section 182 along which the diameter of the distal limb 1 12, 1 14 decreases as the limb 1 12, 1 14 extends towards the distal end(s) 108 of the graft body 102. In such an embodiment, the stented grafts 140, 142 may be similarly shaped to as to correspond to all or a portion of the non- cylindrical lengthwise shape of the distal limbs 1 12, 1 14. For example, as shown in FIG. 12, each stented graft may include a converging lengthwise portion 184 along which the diameter of the stented graft 140, 142 decreases as the graft 140, 142 extends from its first end 146 to its second end 148. The converging lengthwise portions 184 of the stented grafts 140, 142 may then be received within the converging lengthwise portions 182 of the distal limbs 1 12, 1 14 when coupling the stented grafts 140, 142 to the graft body 102.

[0069] It should also be appreciated that the distal limbs 1 12, 1 14 may generally be configured to define any suitable length. For instance, as described above with reference FIGS. 3-12, the distal limbs 1 12, 1 14 generally define the same length. However, in other embodiments, the lengths of the distal limbs 1 12,

1 14 may differ from one another. For instance, FIG. 13 illustrates an embodiment of the graft body 102 having distal limbs 1 12, 1 14 that define varying lengths.

Specifically, as shown, the first distal limb 1 12 defines a length 186 that is longer that a corresponding length 188 of the second distal limb. In such an embodiment, the length(s) of the stented grafts 140, 142 may be modified to accommodate the differing lengths 186, 188 of the distal limbs 1 12, 1 14.

[0070] Referring now to FIGS. 14 and 15, another embodiment of the endograft 100 described above with reference to FIGS. 6 and 7 is illustrated in accordance with aspects of the present subject matter. As shown, unlike the embodiment described above, each distal limb 1 12, 1 14 of the graft body 102 extends lengthwise from the proximal tube portion 1 10 and terminates within one of the common iliac arteries 30, 32. In such an embodiment, each distal limb 1 12, 1 14 may include a first lengthwise limb portion 190 extending within the aortic aneurysm 50 and a second lengthwise limb portion 192 extending within one of the corresponding common iliac arteries 30, 32.

[0071] In such an embodiment, to allow for secure attachment of the distal limbs 1 12, 1 14 to the common iliac arteries 30, 32, a separate stented tube insert 194, 195 (or stent-graft) may be inserted within the second lengthwise limb portion 192 of each distal limb 1 12, 1 14. For example, FIGS. 14 and 15 illustrates first and second stented tube inserts 194, 195 that may be configured to be received within the first and second distal limbs 1 12, 1 14, respectively. For purposes of illustration, FIG. 14 illustrates the stented tube inserts 194, 195 separate from the graft body 102. FIG. 15 illustrates both of the stented tube inserts 194, 195 installed relative to the graft body 102.

[0072] It should be appreciated that the stented tube inserts 194, 195 may generally be configured the same as or similar to the stented grafts 140, 142 described above. For instance, the stented tube inserts 194, 195 may correspond to separate components from the graft body 102. Each tube insert 194, 195 may be configured as an elongated tube formed from a suitable graft material that extends lengthwise between a first end 196 and a second end 197. Additionally, as shown in the illustrated embodiment, each tube insert 194, 195 may be fully supported between its first and second ends 196, 197. For example, a stent(s)

198 may be provided between the first and second ends 196, 197 of each stented tube insert 194, 195 to provide structural support to the insert 194, 195. [0073] As shown in FIG. 15, each stented tube insert 194, 195 may be inserted within the second lengthwise limb portion 192 of each distal limb 1 12, 1 14 to provide a means for attaching the distal limb 1 12, 1 14 to its respective common iliac artery 30, 32. In such an embodiment, the stented tube inserts 194, 195 may be configured to extend entirely within the second lengthwise limb portion 192 of each distal limb 1 12, 1 14. Alternatively, as shown in FIG. 15, a portion of each stented tube insert 194, 195 may be configured to extend proximally beyond the second lengthwise limb portion 192 into the first lengthwise limb portion 192 of each distal limb 1 12, 1 14.

[0074] It should be appreciated that, in several embodiments, one or more nonstructural location identifiers may be provided in association with the disclosed graft body 102. For instance, FIG. 16 illustrates one embodiment of suitable nonstructural location identifiers 201 , 202 that may be used with the disclosed graft body 102. In several embodiments, the location identifiers 201 , 202 may correspond to radiopaque location identifiers. For instance, as shown in FIG. 16, one or more radiopaque markers 201 and/or radiopaque wires 202 may be incorporated into or coupled to the graft body 102. In such an embodiment, the radiopaque location identifiers 201 , 202 may be used to facilitate radiological identification during insertion and/or assembly of the endograft 100. However, given the nature of the location identifiers 201 , 202, such identifiers 201 , 202 may not provide any structural support to the graft body 102.

[0075] As shown in FG. 16, in one embodiment, the location identifiers 201 , 202 are positioned on or within the distal limbs 1 12, 1 14, such as being located at or adjacent to the distal end(s) 108 of the graft body 102. However, in other embodiments, the location identifiers 201 , 202 may be positioned at any other suitable location on or within the graft body 102.

[0076] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

WHAT IS CLAIMED IS:

1 . An endograft for endovascular repair of an abdominal aorta having an aortic aneurysm and an aortic neck, the endograft comprising:

a moderately supported graft body extending lengthwise between a proximal end and a distal end, the graft body including a proximal tube portion and first and second distal limbs, the proximal tube portion extending lengthwise between the proximal end of the graft body and the first and second distal limbs, the first and second distal limbs extending lengthwise between the proximal tube portion and the distal end of the graft body,

wherein the proximal tube portion includes a stented section having a stent configured to provide structural support to the proximal tube portion,

wherein each of the first and second distal limbs correspond to non-stented portions of the graft body.

2. The endograft of claim 1 , wherein at least a portion of the proximal tube portion is configured to be secured to the aortic neck and wherein the distal end of the graft body is configured to be positioned within the aortic aneurysm.

3. The endograft of claim 2, further comprising first and second stented grafts, the first stented graft including a proximal portion configured to be inserted within the first distal limb and a distal portion configured to be received within a first common iliac artery of the abdominal aorta, the second stented graft including a proximal portion configured to be inserted within the second distal limb and a distal portion configured to be received within a second common iliac artery of the abdominal aorta.

4. The endograft of claim 3, further comprising first and second buffer sleeves, the first buffer sleeve configured to be received within the first distal limb such that the first buffer sleeve is positioned between the proximal portion of the first stented graft and the first distal limb, the second buffer sleeve configured to be received within the second distal limb such that the second buffer sleeve is positioned between the proximal portion of the second stented graft and the second distal limb.

5. The endograft of claim 4, wherein the first and second buffer sleeves are non-stented or stented.

6. The endograft of claim 1 , wherein each of the first and second distal limbs defines a non-cylindrical shape along at least a portion of its length.

7. The endograft of claim 1 , wherein a length of the first distal limb differs from a length of the second distal limb.

8. The endograft of claim 1 , wherein each of the first and second distal limbs includes a first lengthwise limb section configured to extend within the aortic aneurysm and a second lengthwise limb section configured to extend within a common iliac artery of the aorta.

9. The endograft of claim 8, further comprising first and second stented tube inserts configured to be inserted within the second lengthwise limb sections of the first and second distal limbs.

10. The endograft of claim 1 , wherein a portion of each of the first and second distal limbs defines a material thickness that is greater than a material thickness of another portion of each of the first and second distal limbs.

1 1 . The endograft of claim 1 , further comprising a non-structural location identifier incorporated within or coupled to at least one of the first distal limb or the second distal limb.

12. The endograft of claim 1 1 , wherein the non-structural location identifier corresponds to a radiopaque marker or a radiopaque wire.

13. The endograft of claim 1 , wherein the graft body is formed from a graft material, each of the first and second distal limbs being formed entirely from the graft material.

14. The endograft of claim 1 , wherein the graft body is formed from a graft material having an outer later and an inner layer, the stent being positioned between the outer and inner layers of the graft material.

15. The endograft of claim 1 , wherein the stented section of the proximal tube portion is configured to be positioned entirely within the aortic neck.