Stent with covering and differential dilation

• US 20040148005A1
• Filed: 10/17/2003
• Published: 07/29/2004
• Est. Priority Date: 10/17/2002
• Status: Active Grant

• Current Assignee: PQ Bypass, Inc.
• Original Assignee: Richard R. Heuser
• Inventors: Heuser, Richard R.
• Granted Patent: US 7,300,459 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• 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 2250/0019 differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2250/0039 differing in diameter

Abstract

A stent is provided with a multi-layer structure, combining one or more mesh layers with one or more film layers. The film layer(s) are configured to substantially prevent growth of an inner lining of a blood vessel, where the stent is placed, through the mesh layer(s). The end-to-end length of the film layer(s) may be greater than the lengths of the mesh layer(s) by at least about 0.5 mm. The mesh and film layers include a radiopaque portion adjacent their ends to provide an X-ray indication of whether the mesh layer(s) have expanded beyond the ends of the film layer(s). If the stent includes inner and outer film layers and a middle mesh layer, the film layers may be sealed together adjacent the ends, encasing and fixing in place the middle layer. The mesh layer may be constructed to be more compliant adjacent its distal end and to expand more rapidly in response to expansion of a balloon catheter as compared to a middle portion of the mesh layer.

Claims

1. A stent for inserting into a human blood vessel and conforming to an inner lining of the blood vessel, the stent comprising:

an outer mesh layer defining a generally cylindrical shape with opposed first and second open ends, the shape of the outer mesh layer defining an outer end-to-end length;

an inner mesh layer defining a generally cylindrical shape with opposed first and second open ends, the inner shape defining an inner end-to-end length;

wherein the inner mesh layer is fitted within the outer mesh layer and the layers have substantially equal end-to-end lengths; and

a film layer defining a generally cylindrical shape with opposed first and second ends, the film shape defining an end-to-end length, the film layer fitted between the inner and outer mesh layers and configured to substantially prevent growth of the inner lining of the blood vessel through the mesh layers.

2. The stent of claim 1 wherein the ends of the film layer extend beyond the ends of the mesh layers.

3. The stent of claim 1 wherein the film layer includes PTFE.

4. The stent of claim 2 wherein the film layer substantially comprises PTFE.

5. The stent of claim 1 wherein the end-to-end length of the film layer is greater than the lengths of the inner and outer mesh layers.

6. The stent of claim 1 wherein one of the ends of the film layer extends beyond one of the ends of the mesh layers at least about 0.5 mm.

7. The stent of claim 6 wherein both of the ends of the film layer extend beyond the ends of the mesh layers at least about 0.5 mm.

8. A stent configured for insertion in a human blood vessel, the stent comprising:

a body with an inner layer providing a first flexible covering;

an outer layer providing a second flexible covering; and

a middle wire mesh layer between the inner and outer layers, the wire mesh layer providing a compressible, self-expanding structure.

9. The stent of claim 8 wherein the inner and outer layers of the stent include PTFE.

10. The stent of claim 8 wherein the wire mesh layer includes nitinol.

11. The stent of claim 8 wherein the middle layer defines first and second ends and the middle layer includes a radiopaque portion adjacent at least one of the ends.

12. The stent of claim 8 wherein the inner and outer layers each define first and second ends, and further wherein the inner and outer layers are sized and aligned with their ends extending beyond the ends of the middle layer.

13. The stent of claim 8 wherein the inner and outer layers each define an end-to-end length and the inner and outer layers are sized to be substantially equal in length.

14. The stent of claim 13 wherein the middle layer defines an end-to-end length that is less than the end-to-end lengths of the inner and outer layers.

15. The stent of claim 8 wherein the inner and outer layers are sealed together adjacent the first and second ends, encasing and fixing in place the middle layer.

16. The stent of claim 8 wherein at least one of the inner and outer layers are provided with a radiopaque portion adjacent at least on of the first and second ends.

17. The stent of claim 16 wherein the middle layer includes a radiopaque portion adjacent at least one of the ends, the combination of the radiopaque portion of the middle layer and the radiopaque portion of the inner or outer layer providing an X-ray indication of whether the middle layer has expanded beyond the ends of the inner and outer layers.

18. A stent delivery system for use in a human blood vessel, the system comprising:

a stent having a mesh layer, the mesh layer defining a middle portion between open, opposed proximal and distal ends and a central lumen communicating between the open ends, and further wherein the mesh layer includes a wire structure; and

a balloon catheter for mounting the stent and inserting and installing the stent inside the human blood vessel, wherein the wire structure of the mesh layer adjacent the distal end is constructed to be more compliant and to expand more rapidly in response to expansion of the balloon catheter as compared to the middle portion of the mesh layer.