Self-Flaring Active Fixation Element for a Stent Graft

• US 20100274345A1
• Filed: 04/24/2009
• Published: 10/28/2010
• Est. Priority Date: 04/24/2009
• Status: Active Grant

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Rust, Matthew
• Granted Patent: US 8,876,883 B2
• Time in Patent Office: Days
• US Class Current: 623/1.130
• CPC Class Codes: A61F 2/07 Stent-grafts
• 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 2002/061 provided with means for allowing access to secondary lumens
• CPC Class Codes: A61F 2002/8483 Barbs
• CPC Class Codes: A61F 2002/8486 provided on at least one of the ends
• CPC Class Codes: A61F 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2230/0019 rectangular
• CPC Class Codes: A61F 2230/0026 trapezoidal
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A stent graft includes a stent graft material of tubular shape and annular shaped stent elements coupled to the stent graft material. The stent graft further includes hooked fixation elements, having hook-end portions and coupling-end, circumferentially spaced about an annular shaped spring attachment element, and coupled to the stent graft at apexes of the spring attachment element. Before deployment the hook-end portions of the apexes of the attachment element and the hooked fixation elements attached thereto are compressed within the space bounded by the interior and exterior sides of the spring attachment element and angled laser cut strut inner surfaces under each apex of the spring attachment element are cut at an angle to cause apex and hook rotation at expansion and deployment. At deployment, the apex and hook-end portions rotate outwardly from the stent graft, partially penetrating the body vessel walls in which the stent graft is deployed and actively fixing the stent graft at the position of deployment.

Claims

1. A structure for fixation of a stent graft to a body vessel comprising:

hollow cylindrically shaped stent graft elements;

an upper spring attachment element of serpentine pattern and coupled to one of said stent graft elements, said upper spring attachment element comprising;

upper apexes;

lower apexes; and

struts interconnecting said upper apexes and said lower apexes;

hooked fixation elements having hook-end portions and coupling-ends, each of said coupling-end coupled to one of said upper apexes;

wherein said hook-end portions lie within a compressed stent cylinder wall space projection bounded by an interior side of said upper apexes and an exterior side of said upper apexes when said stent graft is compressed prior to deployment of said stent graft in said body vessel; and

wherein said hook-end portions rotate outwardly from an expanded stent cylinder wall space projection bounded by said interior side of said upper apexes and said exterior side of said upper apexes to act as a hook element to penetrate said body vessel when said stent graft is expanded at deployment.

2. The structure of claim 1 wherein said stent graft elements are laser cut.

3. The structure of claim 1 wherein said upper spring attachment element is laser cut and wherein said struts at an upper apex are cut to have an angle α

from a radius of said hollow cylindrical shape.

4. The structure of claim 1 wherein said spring attachment element comprises a material having shape memory.

5. The structure of claim 4 wherein said material having shape memory comprises a nickel-titanium alloy.

6. The structure of claim 1 wherein said hook-end portions terminate bluntly.

7. The structure of claim 1 wherein said hook-end portions terminate at a point.

8. The structure of claim 1 wherein said hook-end portions terminate at an angle.

9. The structure of claim 1 wherein said hook-end portions partially penetrate said body vessel at deployment of said stent graft.

10. The structure of claim 1 wherein said upper spring attachment element provides a radial biasing force directed outwardly from a stent graft central axis.

11. The structure of claim 10 wherein said radial biasing force provides passive fixation of said stent graft when said stent graft is expanded at deployment.

12. The structure of claim 1 further including tubular shaped stent graft material coupled to said spring elements.

13. A method of producing a stent graft for active attachment to a body vessel comprising:

producing a hollow cylindrically shaped stent graft element having a spring attachment element of a serpentine pattern comprising upper apexes having hooks connected to said upper apexes extending along a cylindrical surface plane of the upper apexes for a distance beyond the circumferential cylindrical edge of each said upper apexes to act as an element of active fixation when the upper apexes are rotated with the hook tips in a direction outside the cylinder;

lower apexes; and

struts interconnecting said upper apexes and said lower apexes;

laser cutting a hollow cylindrical tube to have laterally facing surfaces of struts emanating from each upper apex at an angle α

from a radius of said cylindrical shape;

shape setting said in an expanded condition where said upper apexes have been rotated with the hook tips in a direction outside the cylinder; and

attaching said hollow cylindrically shaped stent graft element to a tubular end of tubular graft fabric for form a portion of a stent graft.