METHOD OF MAKING A VARIABLE SURFACE AREA STENT

• US 20100116785A1
• Filed: 01/15/2010
• Published: 05/13/2010
• Est. Priority Date: 04/12/2001
• Status: Active Grant

• Current Assignee: Brian P. Cahill, Fuh-Wei Tang, Syed Hossainy
• Original Assignee: Brian P. Cahill, Fuh-Wei Tang, Syed Hossainy
• Inventors: Hossainy, Syed, Tang, Fuh-Wei, Cahill, Brian P.
• Granted Patent: US 8,119,184 B2
• Time in Patent Office: Days
• US Class Current: 216/41
• 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 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0095 radioactive
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2250/0025 differing in roughness
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir

Abstract

A stent of variable surface area as determined by stent struts. The stent can have a variable surface area per unit length which accommodates a therapeutic agent. A patterned distribution of therapeutic agent can be provided throughout the stent. The stent can have an increased level of therapeutic agent near an end of the stent. A decreased level of therapeutic agent can be provided near an end of one embodiment of a stent. Indentations can be provided at the surface of the stent with therapeutic agent disposed therein. The stent can be cut with struts of variable thickness to provide the variable stent surface area.

Claims

1. A method of manufacturing a stent, the stent including a tubular body including a plurality of struts, the struts defining a first end segment of the body, an opposing second end segment of the body, and a middle segment of the body between the first and second end segments, the method comprising depositing a therapeutic agent on the body so that the first or second end segment has a lesser amount or concentration of the agent than the middle segment as a result of a difference in any of surface roughness and indentation, the difference present between struts of the first or second end segment as compared to struts of the middle segment.

2. The method of claim 1, wherein depositing the agent comprises applying a composition including a polymer and the agent on the body.

3. The method of claim 1, wherein a surface area of at least some of the individual struts of the middle segment of the body is greater than a surface area of the struts of the first or second end segment so that a greater amount or concentration of the agent is carried by the struts having the greater surface area.

4. The method of claim 1, wherein the agent is an anti-coagulant.

5. The method of claim 1, wherein the agent is encased in an anti-coagulant barrier.

6. The method of claim 1, further comprising forming the plurality of struts by cutting a stent pattern from a substrate material.

7. The method of claim 1, wherein the first or second end segment has the lesser amount or concentration of the agent than the middle segment as a result of a difference in surface roughness, and the method further comprises performing a roughening process on the outside of the body while avoiding an increase in roughness inside the body.

8. The method of claim 7, wherein the roughening process includes etching by chemical method, plasma method, laser method, or mechanical method.

9. The method of claim 1, wherein the first or second end segment has the lesser amount or concentration of the agent than the middle segment as a result of a difference in surface roughness, and the method further comprises:

masking the first or second end segment with a protective layer; and

etching the middle segment to increase the surface area of the middle segment;

followed by

removing the protective layer.

10. The method of claim 9, wherein the etching of the middle segment includes a process selected from the group consisting of dry etching, sand blasting, and plasma etching.

11. The method of claim 9, wherein after the removing of the protective layer, the agent is deposited onto the struts of the first or second end segment and onto the struts of the middle segment.

12. The method of claim 1, wherein the first or second end segment has the lesser amount or concentration of the agent than the middle segment as a result of a difference in indentations in struts of the middle segment as compared to indentations in struts of the first or second end segment, the indentations in struts of the middle segment having a greater volume than indentations in struts of the first or second end segment.

13. The method of claim 12, wherein at least some of the indentations in struts of the middle segment have a depth greater than about 60 microns.

14. The method of claim 12, wherein the agent is deposited into the indentations in the struts of the first or second end segment and into the indentations in the struts of the middle segment.