Endovascular Implant Having an Integral Graft Component and Method of Manufacture

• US 20100268320A1
• Filed: 04/17/2009
• Published: 10/21/2010
• Est. Priority Date: 04/17/2009
• Status: Abandoned Application

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Clarke, Gerry
• Application Number:
  US12/425,653
• Publication Number:
  US 20100268320A1
• 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 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: B29C 45/14598 Coating tubular articles
• CPC Class Codes: B29C 45/261 having tubular mould cavities
• CPC Class Codes: B29K 2059/00 Use of polyacetals , e.g. POM, i.e. polyoxymethylene or derivatives thereof, as moulding material
• CPC Class Codes: B29L 2031/7534 Cardiovascular protheses

Abstract

A covered stent including an endovascular implant having a polymeric stent structure with an integrally formed membrane-like graft component, also referred to as a stent-graft, and methods of manufacturing the one-piece stent-graft by an injection molding process. A molding system for creating the polymeric stent structure is injected with a melt stream of moldable material that is forced between a parting line of the molding system to create a thin, flexible membrane-like structure within the open areas or interstitial spaces of the molded stent structure. The stent-graft so created is a one-piece, unified structure molded from a polymeric material in a single manufacturing step.

Claims

1. A stent-graft for placement within a body vessel comprising:

a tubular stent structure having a thin membrane-like structure covering spaces within the tubular stent structure and defining at least a portion of a blood flow lumen that extends longitudinally through the tubular stent structure, wherein the tubular stent structure and the thin membrane-like structure are a one-piece component of a polymeric material.

2. The stent-graft of claim 1, wherein the tubular stent structure includes a plurality of frame members and the spaces are interstices formed between adjacent frame members.

3. The stent-graft of claim 1, wherein the thin membrane-like structure is disposed proximate an interior side of the tubular stent structure.

4. The stent-graft of claim 3, wherein the tubular stent structure substantially forms an exterior contact surface of the stent-graft that expands into apposition with a wall of the body vessel.

5. The stent-graft of claim 4, wherein the tubular stent structure is balloon-expandable.

6. The stent-graft of claim 4, wherein the tubular stent structure is self-expanding.

7. The stent-graft of claim 1, wherein the thin membrane-like structure is substantially impermeable.

8. The stent-graft of claim 1, wherein the polymeric material is polyoxymethylene.

9. The stent-graft of claim 1, wherein the thin membrane-like structure has a thickness of approximately 0.001 inch.

10. A method of manufacturing a one-piece stent-graft comprising:

injecting a melt stream of moldable polymeric material into a mold cavity of a molding system, wherein the mold cavity forms a tubular stent framework having interstitial spaces;

filling the mold cavity with the melt until the mold cavity overflows and the melt flows between parting surfaces of the molding system; and

allowing the melt to cover the parting surfaces such that a molded tubular stent framework formed thereby has an integral thin membrane-like structure formed within the interstitial spaces thereof by the melt which has flowed between the parting surfaces.

11. The method of claim 10, wherein the integral thin membrane-like structure has a thickness of approximately 0.0005 inch to 0.001 inch.

12. The method of claim 10, wherein a gap of approximately 0.0005 inch is maintained between the parting surfaces of the molding system such that the integral thin membrane-like structure has a thickness of approximately 0.001 inch.

13. The method of claim 10, wherein the moldable polymeric material is polyoxymethylene.

14. The method of claim 10, wherein the mold cavity has a first portion in a first parting surface of the molding system and a second portion in a second parting surface of the molding system such that the integral thin membrane-like structure is formed within the interstitial spaces substantially midway between exterior and interior surfaces of the molded tubular stent framework.