Tapered endovascular stent graft and method of treating abdominal aortic aneurysms and distal iliac aneurysms

• US 20020052643A1
• Filed: 01/02/2001
• Published: 05/02/2002
• Est. Priority Date: 08/02/2000
• Status: Active Grant

• Current Assignee: Cook Medical Incorporated (Cook Group Incorporated)
• Original Assignee: Boulos Toursarkissian, Mark H. Wholey, Michael H. Wholey
• Inventors: Toursarkissian, Boulos, Wholey, Mark H., Wholey, Michael H.
• Granted Patent: US 6,773,454 B2
• Time in Patent Office: Days
• US Class Current: 623/1.13
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/848 having means for fixation to the vessel wall, e.g. barbs
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/067 modular
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2220/0008 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/0078 hyperboloidal
• CPC Class Codes: A61F 2230/008 paraboloidal

Abstract

The present invention relates to an improved endovascular stent. The endovascular stent is to be used in treating abdominal aortic aneurysms. The endovascular stent has a tapered section which allows it to accommodate markedly large aortas such as the abdominal aorta and still connect to standard modular aortic stent grafts. Methods of utilizing the stent to treat abdominal aortic aneurysms and distal iliac aneurysms are also provided.

Claims

1. An endovascular stent comprising:

a generally cylindrical cephalic section defining a cephalic lumen and having a cross-sectional area;

a tapered mid-section;

caudal section defining a caudal lumen and having a cross-sectional area;

said mid-section disposed between, and attached to both, said cephalic section and said caudal section; and

wherein said cephalic cross-sectional area is larger than said caudal cross-sectional area and said mid-section tapers from said cephalic cross-sectional area to said caudal cross-sectional area.

2. The endovascular stent of claim 1 wherein said caudal section is structured to be attached to a secondary stent graft.

3. The endovascular stent of claim 1 wherein:

said cephalic section, mid-section, and caudal section include a frame; and

said cephalic section, mid-section, and caudal section frame has a covering.

4. The endovascular stent of claim 3 wherein said frame includes an uncovered stent section extending from said cephalic section.

5. The endovascular stent of claim 4 wherein said cephalic section, mid-section, and caudal section frame is an integral frame.

6. The endovascular stent of claim 5 wherein said frame and said cover are structured to have an expanded configuration and an unexpanded configuration.

7. The endovascular stent of claim 6 wherein said frame includes a plurality of helically arranged undulating members containing multiple turns about a common longitudinal axis.

8. The endovascular stent of claim 7 wherein said frame is structured to create a sufficient outward radial strength at said cephalic section to ensure complete sealing against the vessel wall and to create sufficient inward radial strength at said caudal section to insure complete sealing against a second stent graft when said frame is in said expanded configuration.

9. The endovascular stent of claim 8 wherein said undulating members are generally U-shaped and overlap each other in a forward and backward manner along the longitudinal axis.

10. The endovascular stent of claim 9 wherein said undulating members are overlapping on each other in a crisscross manner along a longitudinal axis.

11. The endovascular stent of claim 10 wherein said frame and cover are structured to cooperate with a balloon structured to expand said frame and cover from said unexpanded configuration to said expanded configuration.

12. The endovascular stent of claim 11 wherein said frame is constructed of a memory metal composition.

13. The endovascular stent of claim 3 wherein said covering includes a coating to aid in cell development.

14. The endovascular stent of claim 13 wherein said covering is polytetrafluoroethylene.

15. The endovascular stent of claim 1 wherein said caudal section has an extended length that extends into said mid-section.

16. The endovascular stent of claim 1 wherein:

said cephalic section cross-sectional area is about 800 to 1,200 mm²; and

said caudal section cross-sectional area is about 300 to 600 mm².

17. The endovascular stent of claim 1 wherein:

said cephalic section having a diameter of about 35 mm; and

said caudal section having a diameter of about 24 mm.

18. The endovascular stent of claim 1 wherein said cephalic section, mid-section, and caudal section include a plurality of radiopaque markers.

19. The endovascular stent of claim 1 wherein said cephalic section includes a plurality of protruding structures along a outer surface that will engage a vessel wall.

20. The endovascular stent of claim 1 wherein said caudal section includes a plurality of protruding structures along an inner surface which is structured to engage a plurality of corresponding structures on a secondary stent graft.

21. The endovascular stent of claim 1 wherein said mid-section includes at least one one-way valve structured to allow for the injection of materials outside the said stent graft and into a space occupied by a abdominal aortic aneurysm.

22. A method of using a endovascular stent having a different sized cylindrical end sections and a tapered section therebetween for treating an abdominal aortic aneurysm, said method comprising the steps of:

providing a collapsible endovascular stent having a cephalic section defining a cephalic lumen and having a cross-sectional area, a mid-section, a caudal section defining a caudal lumen and having a cross-sectional area, said mid-section disposed between, and attached to both, said cephalic section and said caudal section, and said cephalic cross-sectional area being larger than said caudal cross-sectional area and said mid-section tapers from said. cephalic cross-sectional area to said caudal cross-sectional area;

collapsing said endovascular stent into a collapsed configuration;

inserting said endovascular stent into a patient via a vascular sheath to a location within the abdominal aorta adjacent a abdominal aortic aneurysm;

expanding said endovascular stent to an expanded configuration wherein said cephalic section engages the abdominal aorta and said caudal section extends into said abdominal aortic aneurysm.

23. The method of claim 22 comprising the further steps of:

providing a modular stent graft having an ipsilateral limb and contralateral limb;

attaching a modular stent graft to said caudal section;

positioning said ipsilateral limb and contralateral limb within the iliac arteries whereby fluid within the abdominal aorta bypasses said abdominal aortic aneurysm before entering the iliac arteries.

25. The method of claim 24 comprising the further steps of:

providing a stent graft having an ipsilateral limb and contralateral limb;

inserting said stent graft in a patient within the abdominal aorta;

attaching said endovascular stent either said to said ipsilateral limb or contralateral limb.

24. A method of using a endovascular stent having a different sized cylindrical end sections and a tapered section therebetween for treating a distal iliac aneurysm, said method comprising the steps of:

providing a collapsible endovascular stent having a flared section having a cross-sectional area, a mid-section, a narrow section having a cross-sectional area, said mid-section disposed between, and attached to both, said flared section and said narrow section, and said flared cross-sectional area being larger than said narrow cross-sectional area and said mid-section tapers from said flared cross-sectional area to said narrow cross-sectional area;

collapsing said endovascular stent into a collapsed configuration;

inserting said endovascular stent into a patient via a vascular sheath to a location within an iliac artery adjacent to a iliac aneurysm;

expanding said endovascular stent to an expanded configuration wherein said flared section engages the iliac artery.