Tapered seams for reducing stent-graft packing density in delivery systems

Abstract

An endovascular stent graft for vascular treatment is provided. The stent is configured to be inserted into a blood vessel while in a radially collapsed configuration and can be opened, assuming a radially expanded configuration, when in place within the blood vessel. The stent graft includes a main body having a proximal end and a distal end. The distal end of the main body is connected to a first leg and a second leg. A first plurality of suture portions extend along a first seam path and connect the main body to the first leg, while a second plurality of suture portions extend along a second seam path and connect the main body to the second leg. At least one of the first seam axis or the second seam axis can be offset as the seam paths do not extend perpendicular to a longitudinal axis of the stent graft.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to a stent graft for use in a medical procedure. The stent graft can include an angled seam to reduce packaging density when the stent graft is in a compressed configuration. BACKGROUND

[0002] Prostheses are implanted in blood vessels and other organs of living bodies. For example, prosthetic vascular endoprostheses composed of biocompatible materials have been used to replace or bypass damaged or occluded natural blood vessels. Generally, vascular endoprostheses include an endoprosthesis anchoring component for holding a tubular endoprosthesis component of suitable endoprosthesis material in its intended position within a blood vessel. The endoprosthesis anchoring component typically includes one or more radially compressible stents that are radially expanded in situ to anchor the tubular endoprosthesis component to a blood vessel wall or an anatomical conduit.

[0003] Vascular endoprostheses (e.g., stent grafts) can be deployed by a less invasive transluminal delivery procedure rather than performing a traumatic, invasive open surgical procedure to implant the endoprosthesis. The luminal or vasculature can be accessed at a convenient and less traumatic access point in the patient’s body, and the stent graft can be guided through the vasculature to the site where the prosthesis is to be deployed. Transluminal deployment typically uses a delivery catheter having a tube or shaft arranged for relative axial movement. For example, an expandable stent graft can be compressed and disposed within the distal end of an outer shaft of a delivery catheter secured to an inner shaft. The delivery catheter can then be manipulated, often through a body lumen, until the distal end of the delivery catheter and the stent graft are positioned at the intended treatment site. The stent graft can then be deployed within the blood vessel and radially expanded. SUMMARY

[0004] According to one embodiment, a stent graft can expand from a radially collapsed configuration to a radially expanded position. The stent graft includes a main body extending along a main longitudinal axis and having a proximal end and a distal end. The stent graft further includes a first leg extending from the distal end of the main body, a second leg extending from the distal end of the main body, and a plurality of stitches coupling the main body to the first leg. When the stent graft is in a pre-deployment configuration prior to insertion into a patient, the plurality of stitches form a stitch path extending in a direction oblique to the main longitudinal axis of the main body.

[0005] According to another embodiment, a stent graft includes a main body extending along a main longitudinal axis and having a proximal end and a distal end. The stent graft also includes a first leg attached to the distal end of the main body along a first seam path extending along the first seam path. The stent graft also includes a second leg attached to the distal end of the main body along a second seam, the second seam being continuous with the first seam and extending along a second seam path. The first seam path is oblique relative to the second seam path when the stent graft is in a pre-deployment configuration prior to insertion into a patient.

[0006] According to yet another embodiment, a stent graft includes a main body extending along a longitudinal axis when the stent graft is in a pre-deployment configuration prior to insertion into a patient. The stent graft includes a first leg extending axially from an axial end in a direction parallel to the longitudinal axis. The stent graft also includes a second leg extending axially from the axial end in a direction parallel to the longitudinal axis, the second leg being narrower than the first leg. The stent graft also includes a plurality of sutures coupling the main body to the first leg, the plurality of sutures forming a suture path extending in a direction oblique to the longitudinal axis. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a side view of a stent graft deployed into a blood vessel (e.g., aorta) according to one embodiment.

[0008] Figure 2A is a cross-sectional view of a blood vessel with a stent graft in a radially compressed configuration according to one embodiment, showing a suture protrusion along one transverse axis.

[0009] Figure 2B is a cross-sectional view of a blood vessel with a stent graft in a radially compressed configuration according to one embodiment. Figure 2A

[0010] Figure 3A is a front view of a stent graft with an axially offset seam according to one embodiment.

[0011] Figure 3B is a side view of a stent graft according to one embodiment. Figure 3A

[0012] Figure 4 is a top plan view of a stent graft according to one embodiment with axially offset seams joining multiple legs to other main bodies of the stent graft.

[0013] Figure 5 is a schematic view of fabric cutting and suturing along two different axes of the same stent graft according to one embodiment. DETAILED DESCRIPTION​​

[0014] Embodiments of the application are described herein. It should be understood, however, that the disclosed embodiments are merely examples and that other embodiments can be implemented in various and alternative forms. The figures are not necessarily to scale; some features can be exaggerated or minimized for purposes of illustration. The specific structural and functional details disclosed herein are not to be interpreted as limiting, but are merely representative of representative embodiments of the technology taught by the present disclosure. As such, the particular

[0015] Directional terms used herein are made with reference to the views and orientations shown in the exemplary drawings. A central axis is shown in the figures and described below. Terms such as "outer" and "inner" are relative to the central axis. For example, an "outer" surface refers to a surface that faces away from the central axis, or is located outward of another "inner" surface. Terms such as "radial," "diameter," "circumference," and the like are also relative to the central axis. The terms "front," "back," "up," "down," and the like refer to the directions referenced in the drawings.

[0016] As used herein, the proximal end of a bifurcated stent graft or other prosthesis is the end closest to the heart via the path of blood flow, while the distal end is the end farthest from the heart during deployment (e.g., downstream of the blood flow). In contrast, the distal end of a catheter is typically identified as the end farthest from the operator (the handle), while the proximal end of the catheter is the end closest to the operator (the handle). However, one skilled in the art will appreciate that the descriptions of stent grafts and delivery systems can be consistent or reversed in actual use, depending on the access location.

[0017] The following detailed description is merely exemplary in nature and is not intended to limit the application or the application and uses of the application. Although the description is presented in the context of treating a blood vessel such as the aorta, the teachings of the present application can also be used in any other body passageway deemed useful, such as the coronary arteries, carotid arteries, and renal arteries, among others.

[0018] Endovascular stent grafting or endovascular aneurysm repair (EVAR) is a method of treating abdominal aortic aneurysms or thoracic aortic aneurysms that is less invasive than open surgical procedures. Endovascular stent grafting uses an endovascular stent graft to reinforce the aortic wall and help prevent the damaged area from rupturing by excluding the aneurysm from blood flow. Stent grafts are generally tubular open-ended structures that provide support to damaged, collapsed, or occluded blood vessels, such as the aorta. Stent grafts have flexibility, allowing them to be inserted through tortuous paths in blood vessels and conform to them. For example, a stent graft can be radially expanded from a radially compressed (or radially collapsed) configuration for delivery to an affected blood vessel site to a radially expanded configuration when deployed at the affected blood vessel treatment site, where the radially expanded configuration has a larger diameter than the radially compressed configuration. The stent graft can be inserted and expanded to the radially expanded configuration from the radially compressed configuration by a self-expanding mechanism or by using, for example, a balloon catheter.

[0019] In one example, an EVAR procedure can include inserting a guidewire into a portion of a patient, such as the femoral artery. After the guidewire is inserted into the artery, it can be gently pushed toward the aneurysm site. A stent graft delivery system, which can include a catheter and a stent graft, can be placed over the guidewire and inserted into the aneurysm site along the guidewire. The stent graft can be guided to the aneurysm site in its radially compressed configuration within the catheter. There can be radiopaque markers on the distal end of the stent graft delivery system or on the stent graft itself to allow the surgeon to guide the stent graft into the proper position. Once in the proper position, the stent graft can be expanded from the radially compressed configuration to the radially expanded configuration. This can be accomplished by, for example, pulling back the stent graft covering, allowing the stent graft to expand due to its fabric biasing outward. Once deployed in the radially expanded configuration, the stent graft can be held in place with a metal hook or stent. The catheter can then be removed while leaving the stent graft in place.

[0020] In some applications, the blood vessel wall or anatomical conduit in which the stent graft is to be implanted is highly curved or angled. In addition, the packing volume within the conduit can be limited.

[0021] Figure 1An example of stent graft 10 in a radially expanded configuration after deployment within a blood vessel 12 is shown, in this case, the blood vessel is a patient's aorta, more specifically, an abdominal aorta. Once secured within blood vessel 12, stent graft 10 provides a tube or conduit for blood flow, directing blood flow through stent graft 10. If stent graft 10 is positioned within an aneurysm 11 of blood vessel 12, blood flow through stent graft 10 can reduce pressure within the aneurysm and cause it to shrink (rehabilitate) or remain stable in size. In one embodiment, the graft material of stent graft 10 is impermeable, for example, is a polyester terephthalate (PET), expanded polyester terephthalate (ePET), polytetrafluoroethylene (PTFE), or other impermeable graft material. Because the graft material is impermeable, blood or other fluids can be prevented from passing through the graft material.

[0022] As shown in Figure 1 stent graft 10 can include a main body 14, a first leg 16 extending from main body 14, and a second leg 18 extending from main body 14. First leg 16 can be ipsilateral to the deployment location of the initial guidewire, while second leg 18 can be contralateral to first leg 16 and can be shorter than first leg 16. First leg 16 can extend into a first iliac artery 20, while second leg 18 can extend into a second iliac artery 22. First leg 16 and second leg 18 can also direct blood flow therethrough, allowing those portions of the iliac arteries to heal and stress to be removed from those areas of the arteries. A second stent graft can subsequently be inserted and attached to one or both of first leg 16 and second leg 18 to lengthen the overall profile of the stent graft.

[0023] First leg 16 can be connected to main body 14 by a suture or seam. Likewise, second leg 18 can be connected to main body 14 by a suture or seam. When stent graft 10 is in a radially collapsed configuration (e.g., during delivery into a patient), the seams at the interface between main body 14 and legs 16, 18 can converge. Figures 2A-2B This concept is illustrated. In Figure 2A for illustrative purposes, stent graft 10 is shown inserted into blood vessel 12 and any external catheter is removed. Stent graft 10 is in its radially collapsed configuration and is being guided through blood vessel 12 via guide 13. Multiple sutures 15 (e.g., sutures connecting main body 14 to one or both of legs 16, 18) can form seams that can create bulges or humps 19 on the exterior of stent graft 10 during deployment. This is due to the material of sutures 15 being very close in the axial direction. For example, this can reduce the available space within the catheter during delivery. While stent graft 10 is in its radially expanded configuration (as shown in FIG. 1), the humps 19 can be less pronounced or not present at all. Figure 2BThe protrusions or bulges 19 of the suturing material disappear when the stent graft 10 is in its radially collapsed configuration (as shown in Figure 2A and remain present during the insertion phase when the stent graft 10 is in its radially expanded configuration (as shown in

[0024] Accordingly, in accordance with various embodiments described herein, the stent graft is provided with suturing sections or lines that define an oblique suturing path. As used herein, the term "oblique" is intended to mean angled or canted at an angle other than a right angle or a parallel angle. Also, as used herein, the term "suturing path" or "seaming path" is intended to mean the average or nominal direction of a set of suturing sections that form at least one seam. Of course, within each seam, a plurality of individual or local suturing sections (e.g., a small group of suturing sections) can be oriented in different directions, but the "suturing path" in the present invention is intended to mean the overall direction of the set of suturing sections as a collective; in other words, the nominal direction of the suturing sections. In one embodiment, a set of 30 to 100 suturing sections can collectively define one seam path, such that the seam path extends along a path that reflects the nominal direction of the 30 to 100 suturing sections.

[0025] A stent graft having an oblique seam path is generally shown in Figures 3A-3B where the stent graft has seams 24 connecting the body 14 to the leg portions 16, 18, where the seams 24 are oblique with respect to the length of the stent graft, as will be further described below. While only two leg portions 16, 18 are shown in this figure and Figure 4 more than two leg portions can be provided. For example, three, four, or five leg portions can extend from the body 14 and can be attached thereto via seams. The suturing sections that join the body to at least one of the leg portions can be angled with respect to the longitudinal axis of the body and / or leg portion. This allows the suturing sections of the seams to be more spread out along the length of the stent graft when the stent graft is in its radially collapsed configuration. This can remove or reduce the size of the bulges of the suturing sections described above when in the radially collapsed configuration. By forming seams that distribute the suturing sections or suturing material along the length of the stent graft, the packing of this material will effectively shrink the cross-sectional area of the stent graft at a given axial location.

[0026] Referring to Figure 4 , a stent graft 30 having such oblique seams is shown in accordance with one embodiment. The stent graft 30 can be used for abdominal aortic aneurysm (AAA), thoracoabdominal aortic aneurysm (TAAA), or any other aortic aneurysm that requires the division of blood flow into multiple lumens. Figure 4Stent-graft 30 is shown in its radially expanded configuration, not deployed in a patient. Stent-graft 30 has a body 32 extending from a proximal end 33 to a first leg 34, and a second leg 36 located at a distal end 35 of body 32. A first seam 38 joins first leg 34 to body 32. A second seam 40 joins second leg 36 to body 32. First seam 38 and second seam 40 can be continuous, as the suturing is performed continuously and uninterruptedly as first leg 34 and second leg 36 are joined to body 32. In one embodiment, first leg 34 feeds into or connects to first and second legs 42, 44 (also referred to as branch legs). Each of legs / branch legs 42, 44 is an optional addition to stent-graft 30 for extending (directly or via an additional extension) into a corresponding blood vessel (e.g., the renal artery, celiac artery, and / or SMA artery). Second leg 36 can be a bypass leg to allow flow into the distal aorta. Thus, in some embodiments, the proximal end of the first leg 34 can be connected to the body 32 via a seam or stitching, and the distal end of the first leg 34 can be connected to the first leg 42 and the second leg 44. A third seam 46 joins the first leg 34 to the first leg 42, and a fourth seam 48 joins the first leg 34 to the second leg 44. For example, each seam 38, 40, 46, 48 can include a fabric, polymer, or metal stitching. While the illustrated embodiment has two legs, other embodiments may have three or more legs. In another embodiment, two or more legs may also be attached to the second leg 36.

[0027] like Figure 4 As shown, body 32 extends along major longitudinal axis 49. When stent-graft 30 is in the radially expanded configuration, not deployed in various blood vessels of a patient, each of legs 34, 36, 42, 44 extends along a respective axis parallel to major longitudinal axis 49. In other words, stent-graft 30 is shown in FIG3 in a pre-deployed configuration, wherein stent-graft 30 has not yet been compacted or compressed to fit within a catheter for insertion into a patient.

[0028] Each seam includes a plurality of stitches extending along a stitch path. For example, the first seam 38 includes a first plurality of stitches extending along a first stitch path 50, also referred to as a seam path or seam axis. Similarly, the second seam 40 includes a plurality of stitches extending along a second stitch path 52. At least one or both of the stitch path axes 50, 52 may extend at an angle that is oblique relative to the longitudinal axis 49 and orthogonal or perpendicular to the normal axis of the axis 49. Figure 4In the illustrated embodiment, only the first suture path 50 is oblique with respect to the longitudinal axis 49. However, in other embodiments, the second suture path 52 is parallel or collinear with the first suture path 50 and extends obliquely with respect to the longitudinal axis 49. In yet other embodiments, both the first suture path 50 and the second suture path 52 can be oblique to the longitudinal axis 49, but at different angles. In another embodiment, the second suture path 52 can be oblique to the longitudinal axis 49, while the first suture path 50 is orthogonal to the longitudinal axis 49.

[0029] In one embodiment, the first suture path 50 and the second suture path 52 form an acute angle a1. In one embodiment, a1 is between 5 degrees and 20 degrees, and in a more particular embodiment can be between 5 degrees and 10 degrees. This will result in an acute angle between the first suture path 50 and the longitudinal axis 49 of between 70 degrees and 85 degrees, and in the respective embodiments of between 80 degrees and 85 degrees. These angles allow the suture to deploy along the axial direction of the stent graft 30 to reduce or eliminate the prevalence of bulges or elevations of the suture material in the radially compressed configuration, without increasing the length of the seam to an undesirable amount that can reduce strength and increase material usage.

[0030] By providing at least one suture path 50, 52 that extends in an oblique direction with respect to the longitudinal axis 49, the suture between the body 32 and at least one of the leg portions 34, 36 deploys along the length of the stent graft 30. Thus, when the stent graft 30 is in its radially compressed configuration, the suture does not bunch up into bulges or elevations on the outer profile of the stent graft 30 to the extent that would impede the stent graft 30 from packing or moving within a catheter (as explained above with reference to Figures 2A-2B As explained herein, in some embodiments, only one suture path 50 is oblique to the longitudinal axis. This suture path is at the junction of the body 32 and the first leg portion 34, which can be wider than the second leg portion 36. By having an oblique suture path at the junction between the larger of the two leg portions and the body, the suture can deploy along a portion of the length of the stent graft that would otherwise have a significant amount of suture bunching up due to the relatively larger width of the first leg portion 34.

[0031] Reference is made to Figure 4One or more of the seams connecting the first leg 34 to the legs 42, 44 can be oblique to the longitudinal axis 49. In particular, in one embodiment, the third seam 46 includes a third plurality of stitches extending along a third stitching path 54, and the fourth seam 48 includes a fourth plurality of stitches extending along a fourth stitching path 56. As with the first and second seam axes 50, 52, the third seam axis 54 can be angled relative to the fourth seam axis 56. For example, the fourth seam axis 56 can extend in a direction orthogonal to the longitudinal axis 49, while the third seam axis 54 can extend in a direction oblique to the fourth seam axis 56. In other embodiments, both axes 54, 56 extend in directions oblique to the longitudinal axis 49. In still other embodiments, the third seam axis 54 and the fourth seam axis 56 can both be oblique to the longitudinal axis 49, but at different angles. In another embodiment, the fourth seam axis 56 can be oblique to the longitudinal axis 49, while the third seam axis 54 is orthogonal to the longitudinal axis 49. The third and fourth stitching paths 54, 56 can intersect at an angle a2, which can be similar to or equal to ai.

[0032] By providing at least one stitching path 54, 56 that extends in an oblique direction along the longitudinal axis 49, the stitches between the first leg 34 and at least one of the legs 42, 44 are spread out along the length of the stent graft 30. As a result, when the stent graft 30 is in its radially compressed configuration, the stitches do not bunch up into protrusions or bulges on the outer profile of the stent graft 30 to the extent that they would impede the stent graft 30 from packing or moving within a catheter.

[0033] Figure 5 A plan view of the fabric 60 is shown, where the fabric 60 is cut to shape and stitched together to form the shape of the stent graft 30. The fabric 60 can be impermeable, such as polyethylene terephthalate (PET), expanded polyethylene terephthalate (ePET), polytetrafluoroethylene (PTFE), or other impermeable graft material. The fabric can include a first fabric portion 62 that ultimately forms the main body 32, a second fabric portion 64 that ultimately forms the first leg 34, and a third fabric portion 66 that ultimately forms the second leg 36.

[0034] At the distal end of the fabric 60, the first fabric portion 62 includes a first edge 68 and a second edge 70. The second edge 70 extends generally perpendicular to a longitudinal edge 72 of the first fabric portion 62. This allows the body 32 to have a portion of its axial end extend generally perpendicular to the longitudinal axis 49. However, unlike the second edge 70, the first edge 68 extends in a direction that is offset or angled from the second edge 70 and the longitudinal edge 72 (e.g., not perpendicular). The second fabric portion 64 has a proximal edge 74 that is offset or angled to match the shape of the first edge 68. A seam 75 or the like can attach the proximal edge 74 of the second fabric portion 64 to the first edge 68 of the first fabric portion 62. This forms the first leg portion 34 with an offset seam axis 50. The third fabric portion 66 has a proximal edge 76 that corresponds in shape to the second edge 70 of the first fabric portion 62. Again, a seam 77 or the like can attach the proximal edge 76 to the second edge 70. This forms the second leg portion 36 with a seam axis 52 that is angled relative to the seam axis 50.

[0035] While the example embodiments have been described above, it is not meant that these embodiments describe all possible forms of the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the application. As previously described, features of various embodiments can be combined to form further embodiments of the present application not explicitly described or illustrated. While various embodiments can be described as providing advantages or superior features relative to other embodiments or prior art implementations, a person of ordinary skill in the art will recognize that one or more features or characteristics can be omitted to achieve the desired overall system attributes depending on the specific application and implementation. These attributes can include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. Thus, where any embodiment is described as being less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments do not depart from the scope of the present application and can be desirable for particular applications.

Claims

1. A stent graft expandable from a radially collapsed configuration to a radially expanded position, the stent graft comprising: a body extending along a major longitudinal axis and having a proximal end and a distal end; a first leg extending from a distal end of the body; a second leg extending from a distal end of the body; as well as and a first plurality of sutures coupling the body to the first legs, wherein the first and second legs extend along an axis parallel to a major longitudinal axis of the body when the stent graft is in a pre-positioned configuration prior to insertion into a patient, and the first plurality of sutures form a first suture path extending in a direction oblique to the major longitudinal axis of the body, wherein oblique means at an angle other than a right angle or parallel.

2. The stent graft of claim 1 , further comprising a second plurality of sutures coupling the body to the second leg, the second plurality of sutures forming a second suture path, at least a portion of the second suture path being oblique to the first suture path.

3. The stent graft according to claim 2, wherein: The second suture path is perpendicular to the primary longitudinal axis when the stent graft is in the pre-positioned configuration.

4. The stent graft according to claim 1, wherein: The first leg has a proximal end connected to the distal end of the body, and the first leg has an opposite distal end, wherein the stent graft further includes a leg connected to the distal end of the first leg.

5. The stent graft of claim 4, further comprising a second plurality of sutures connecting the distal ends of the first legs to the legs, the second plurality of sutures extending along a second suture path oriented at an acute angle relative to the main longitudinal axis of the body.

6. The stent graft of claim 5, further comprising a second leg connected to the distal end of the first leg, and a third plurality of sutures connecting the distal end of the first leg to the second leg.

7. The stent graft according to claim 6, wherein: The third plurality of sutures extends along a third suture path that is oriented at an angle relative to the second suture path.

8. The stent graft according to claim 5, wherein: The acute angle is in the range of 70 degrees to 85 degrees.

9. The stent graft according to claim 8, wherein: The acute angle is in the range of 80 degrees to 85 degrees.

10. A stent graft comprising: a body extending along a major longitudinal axis and having a proximal end and a distal end; a first leg attached to the distal end of the body via a first seam extending along a first seam path; as well as and a second leg attached to the distal end of the body by a second seam continuous with the first seam and extending along a second seam path, wherein the first leg and the second leg extend along an axis parallel to a major longitudinal axis of the body when the stent graft is in a pre-positioned configuration prior to insertion into a patient, the first seam path is oblique to the major longitudinal axis, and the first seam path is oblique relative to the second seam path, wherein oblique means at an angle other than a right angle or parallel.

11. The stent graft according to claim 10, wherein: The second seam path extends perpendicular to the main longitudinal axis, and the first seam path extends at an acute angle relative to the main longitudinal axis.

12. The stent graft according to claim 10, wherein: An angle between the first seam path and the second seam path is between 5 degrees and 20 degrees.

13. The stent graft according to claim 10, wherein: The first leg has a proximal end connected to the distal end of the body, and the first leg has an opposite distal end, wherein the stent graft further includes a leg connected to the distal end of the first leg.

14. The stent graft of claim 13, further comprising a third seam connecting the distal end of the first leg to the leg, the third seam extending along a third seam path oriented at an acute angle relative to the main longitudinal axis of the body.

15. The stent graft of claim 14, further comprising a second leg connected to the distal end of the first leg by a fourth seam, the fourth seam extending along a fourth seam path that is angled relative to the third seam path.

16. The stent graft according to claim 10, wherein: The first leg is wider than the second leg.

17. A stent graft comprising: a body extending along a longitudinal axis when the stent graft is in a pre-positioned configuration prior to insertion into a patient, the body having an axial end; a first leg attached to the axial end and extending axially therefrom in a direction parallel to the longitudinal axis; a second leg attached to the axial end and extending axially from the axial end in a direction parallel to the longitudinal axis, the second leg being narrower than the first leg; as well as A first plurality of stitches couples the body to the first leg, the first plurality of stitches forming a first stitch path extending in a direction oblique to the longitudinal axis, wherein oblique means at an angle other than right or parallel.

18. The stent graft of claim 17, further comprising a second plurality of sutures coupling the body to the second leg, the second plurality of sutures forming a second suture path extending in an oblique direction relative to the first suture path.

19. The stent graft according to claim 17, wherein: The first leg includes an axial end, and wherein the stent graft further includes a first leg and a second leg extending from the axial end of the first leg.

20. The stent graft according to claim 19, wherein The first leg is coupled to the first leg via a third plurality of sutures forming a third suture path and extending along the third suture path, wherein the second leg is coupled to the first leg via a fourth plurality of sutures forming a fourth suture path and extending along the fourth suture path, and wherein the third suture path and the fourth suture path are angled relative to each other.

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