EP0809981A1
Expired / Lapsed
EP
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Biodegradable stent
Assignee: General Vascular Devices Ltd
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Filing: 1997-05-07
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Granted: —
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Expires: 2017-05-07
Abstract
Abstract An expandable, biodegradable stent for use within a body lumen comprises a hollow tube made from a copolymer of L-lactide and ∈-caprolactone that is not plastically expandable at normal body temperatures, and that is expandable using thermo-mechanical means at a temperature between about 38-55°C using a balloon catheter. The invention also relates to a method of making such a stent and to a method of deploying such a stent within the body.
Inventors
- 👤 Kevin E. BioEngineered Mat. Inc. Healy
- 👤 Gary S. General Vascular Dev. Ltd. Dorfman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 04:15
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/82; A61F2210/00; A61F2210/0004
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
85 words
An expandable, biodegradable stent for use within a body lumen comprising a hollow tube made from a copolymer of L-lactide and ε-caprolactone that, in unexpanded form, is of a first diameter sufficient to be retained upon a balloon catheter for placement within the body lumen, and that is not plastically expandable at normal body temperatures, and that is expandable using thermo-mechanical means at a temperature between 38-55°C when the balloon catheter is inflated to a second diameter sufficient to be retained within the body lumen.
Claim 2
Dependent Claim
23 words
A stent as claimed in Claim 1, wherein the molar ratio of L-lactide to ε-caprolactone is in the range from 90:10 to 98:2.
Claim 3
Dependent Claim
15 words
A stent as claimed in Claim 1 or Claim 2, wherein the tube in imperforate.
Claim 4
Dependent Claim
33 words
A stent as claimed in Claim 1 or Claim 2 wherein the tube is perforated, the perforations placed at a distance relative to each other corresponding to cell ingrowth within the body lumen.
Claim 5
Dependent Claim
13 words
A stent as claimed in any preceding claim, wherein the tube in nonwoven.
Claim 6
Dependent Claim
15 words
A stent as claimed in any preceding claim, wherein the tube incorporates a radio-opaque material.
Claim 7
Dependent Claim
17 words
A stent as claimed in any preceding claim wherein the tube is coated with a lubricious material.
Claim 8
Dependent Claim
15 words
A stent as claimed in Claim 7 wherein the thickness of the coating in 25µm.
Claim 9
Dependent Claim
46 words
A stent as claimed in Claim 7 or Claim 8 wherein the coating is a copolymer or blend of a biodegradable material with lubricious materials selected from monomer constituents of poly(ethylene glycol), poly(vinyl alcohol), poly(vinyl pyrrolidine), poly(acrylic acid), poly(methacrylic acid) and polyacrylamide, or the polymers thereof.
Claim 10
Dependent Claim
24 words
A stent as claimed in any preceding claim wherein the tube includes a drug, either blended with the copolymer or blended with the coating.
Claim 11
Dependent Claim
38 words
A stent as claimed in Claim 8 wherein the drug is selected from antithrombotics, anticoagulants, antimitogens, antimitotoxins, antisense oligonucleotides, gene therapy vehicles, nitric oxide, growth factors and inhibitors, Hirudin, Hirugen, Hirulog, PPACK, D-FPRCH 2 Cl, Heparin, and Warfarin.
Claim 12
Independent Claim
88 words
A method for making a stent as defined in any one of claims 1 to 11 comprising the steps of: providing a copolymer of L-lactide and ε-caprolactone that is not expandable at normal body temperatures, and that is thermo-mechanically expandable at a temperature between 38-55°C; creating a tube from the copolymer having a diameter sufficient to permit the tube to be retained upon an unexpanded balloon catheter for insertion into a body lumen; and cutting the tube into lengths for use as a stent within the body lumen.
Claim 13
Dependent Claim
14 words
A method as claimed in claim 12 wherein the tube is created by extrusion.
Claim 14
Dependent Claim
14 words
A method as claimed in claim 12 wherein the tube is created by dip-coating.
Claim 15
Independent Claim
25 words
A method as claimed in any one of claims 12 to 14 further comprising the step of micromachining perforations in the tube using a laser.
Claim 16
Independent Claim
115 words
A method for making a stent as defined in any one of claims 1 to 11 comprising the steps of: providing a copolymer of L-lactide and ε-caprolactone that is not expandable at normal body temperature, and that is thermo-mechanically expandable at a temperature between about 38-55°C; creating a tube from the copolymer having a diameter sufficient to permit the tube to be retained upon an unexpanded balloon catheter for insertion into a body lumen; cutting the tube into lengths for use as a stent within the body lumen; and, thermo-mechanically expanding the stent within the body lumen to increase the hoop strength of the stent by a sufficient amount to substantially support the body lumen.
Claim 17
Dependent Claim
28 words
The method of making a stent of claim 16, wherein the stent is thermo-mechanically expanded so that the draw ratio of the expanded stent is greater than 2.0.
References Cited (Backward Citations)
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WO1993015787A1
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