Intra-arterial stent with the capability to inhibit intimal hyperplasia

• US 5,059,166 A
• Filed: 12/11/1989
• Issued: 10/22/1991
• Est. Priority Date: 12/11/1989
• Status: Expired due to Term

• Current Assignee: Medical Innovative Technologies R&D Limited Partnership
• Original Assignee: Medical Innovative Technologies R&D Limited Partnership
• Inventors: Fischell, Robert E., Fischell, Tim A.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/448,691
• Time in Patent Office: 680 Days
• Field of Search: 128/11, 128/804, 128/899, 600/1, 600/3, 600/12, 606/108, 606/139, 424/1.1
• US Class Current: 600/3
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2210/0095 radioactive
• CPC Class Codes: A61K 51/1282 Devices used in vivo and carrying the radioactive therapeutic or diagnostic agent, therapeutic or in vivo diagnostic kits, stents
• CPC Class Codes: A61L 31/14 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61N 5/1002 Intraluminal radiation therapy

Abstract

Intra-arterial stents are frequently used subsequent to balloon angioplasty to maintain arterial patency. The most frequent cause for failure to maintain patency is the rapid growth of the injured arterial tissue through the openings in the stent, which rapid growth is called "intimal hyperplasia." Since irradiation from a radioisotope source is capable of selectively inhibiting the growth of hyperproliferating cells as compared with normal cells, a radioisotope material which forms part of the stent can be used to decrease the rate of arterial reclosure. The radioisotope could be placed inside the stent, alloyed into the metal from which the stent is made, or preferably, it can be coated onto the stent'"'"'s exterior surface. Beta emitting radioisotopes having a half-life between 1 and 100 days would be best suited as a stent coating because of their comparatively short range of action within human tissue, and because of their comparatively short half-life. An anti-thrombogenic coating placed on the outer surface of the radioisotope stent would further reduce arterial reclosure by decreasing stent thrombogenicity.

Claims

1. An intra-arterial stent comprising a generally tubular structure whose external surface is adapted to engage the arterial wall and which is patent throughout its entire interior length, said stent being formed from a radioactive material which is outwardly, radially expandable after percutaneous insertion into an artery, the radioactive material being adapted to be imbedded into the plaque so that the radioactive material preferentially emits radiation that can reduce the proliferation of cells in the arterial wall that are in close proximity to said stent.

2. The stent of claim 1 in which the radioactive material emitting the radiation is a radioisotope.

3. The stent of claim 2 in which said radioisotope is located within the structural material of said generally tubular structure of the stent.

4. The stent of claim 2 in which said radioisotope is plated onto said generally tubular structure of the stent.

5. The stent of claim 2 including an outer coating of anti-thrombogenic material.

6. The stent of claim 2 in which said radioisotope is a beta particle emitting radioisotope.

7. An intra-arterial stent comprising a generally tubular, thin-walled structure adapted to be expanded radially outward against the wall of an artery in a human body at least part of said stent being formed from a radioisotope material which is radially expandable, and said radioisotope material being adapted to be imbedded into the plaque within the arterial wall and further being adapted to decrease the rate of proliferative cell growth of the intimal cells.

8. The stent of claim 7 in which said radioisotope has a half-life of less than 100 days.

9. A method to decrease intimal hyperplasia caused by the treatment of an arterial stenosis the method comprising:

percutaneous insertion of a radioisotope source into an artery by means of a catheter so that it is positioned at the site of the arterial stenosis, said radioisotope source being formed from a plurality of thin, wire-like, interconnected, radially expandable parts in the form of an intra-arterial stent;

radially expanding the radioisotope source so that it becomes imbedded in the plaque within the arterial wall; and

,

removal of the catheter from the artery.

10. The method of claim 9 further comprising the step of dilating the stenosis by the use of a balloon angioplasty catheter prior to the insertion of the stent.

11. The method of claim 9 further comprising the step of excising at least some of the atheromatous plaque of the stenosis by means of an atherectomy catheter prior to the insertion of the stent.