Balloon expandable polymer stent with reduced elastic recoil
View Patent ↗A process for forming a stent of a polymer material which includes the steps of: a) forming a generally tubular stent; b) radially expanding the stent to produce an expanded diameter stent; and then, c) annealing the expanded diameter stent to shrink its diameter to a reduced diameter.
1. A process comprising the steps of:
a) forming a generally tubular stent of polymer material;
b) radially expanding the stent to produce an expanded diameter stent; and then,
c) annealing the expanded diameter stent to shrink its diameter to a reduced diameter, wherein the steps a)-c) are all performed prior to deployment of the stent in a body.
2. A process as in claim 1 further comprising at least one time repeating steps b) and c) in sequence on said stent.
3. A process as in claim 1 wherein in step a) the stent is formed by molding the polymer material.
4. A process as in claim 3 wherein the polymer material is thermoplastic.
5. A process as in claim 4 wherein the polymer material is biodegradable.
6. A process as in claim 1 wherein the polymer material is selected from the group consisting of poly(alpha-hydroxy acid), polylactic acid-polyethylene oxide copolymers; modified cellulose; collagen or other connective proteins; adhesive proteins; hyaluronic acid; polyanhydrides; polyphosphoesters; poly(amino acids); copolymers thereof; and mixtures of any of said materials.
7. A process as in claim 6 wherein the polymer material is a poly(alpha-hydroxy acid) selected from the group consisting of homopolymers and copolymers of polylactide (PLA), poly-L-lactide (PLLA), poly-D-lactide (PDLA), polyglycolide (PGA), polydioxanone, polycaprolactone, poly(hydroxybutyrate), polygluconate, and mixtures thereof.
8. A process as in claim 1 wherein the step b) is performed at a temperature below the glass transition temperature of the polymer material.
9. A process as in claim 8 wherein the step b) is performed at room temperature.
10. A process as in claim 1 wherein the step c) is performed at a temperature above the glass transition temperature of the polymer material.
11. A process as in claim 10 wherein the step c) is performed at a temperature within the range of about 90° C. to about 150° C.
12. A process as in claim 1 wherein in step a) a pattern of perforations is provided in the tube wall.
13. A process comprising the steps of:
a) forming a generally tubular article of polymeric material;
b) radially expanding the article to produce an expanded diameter article; and then,
c) annealing the expanded diameter article to shrink its diameter to a reduced diameter,
wherein the steps a)-c) are all performed prior to deployment of the tubular article in a body, and wherein at least one time steps b) and c) are repeated in sequence on said tubular article.
14. A medical device adapted for body lumen navigation and/or treatment produced by the process of claim 13 .
15. A process comprising the steps of:
a) forming a generally tubular article of polymeric material;
b) radially expanding the article to produce an expanded diameter article; and then,
c) annealing the expanded diameter article to shrink its diameter to a reduced diameter,
wherein the steps a)-c) are all performed prior to deployment of the tubular article in a body, and wherein the polymer material is a biodegradable polymer.
16. A process as in claim 15 wherein at least one time steps b) and c) are repeated in sequence on said tubular article.
17. A process as in claim 15 wherein the polymer material is selected from the group consisting of poly(alpha-hydroxy acid), polylactic acid-polyethylene oxide copolymers; modified cellulose; collagen or other connective proteins; adhesive proteins; hyaluronic acid; polyanhydrides; polyphosphoesters; poly(amino acids); copolymers thereof; and mixtures of any of said materials.
18. A medical device adapted for body lumen navigation and/or treatment produced by the process of claim 15 .
19. A process comprising the steps of:
a) forming a tube of polymeric material;
b) radially expanding the tube to produce an expanded diameter tube;
c) annealing the expanded diameter tube to shrink its diameter to a reduced diameter; and subsequently
d) forming a stent from the annealed tube,
wherein the steps a)-d) are all performed prior to deployment of the stent in a body.
20. A process as in claim 19 wherein the steps b) and c) are repeated at least once on said tube before step d) is performed.
21. A process as in claim 19 wherein in step d) the stent is formed by machining or etching the reduced diameter tube obtained from step c).
22. A process comprising the steps of:
a) forming a generally tubular article;
b) radially expanding the tubular article to produce an expanded diameter tubular article; and
c) annealing the expanded diameter tubular article to shrink its diameter to a reduced diameter,
the process further comprising
d) forming the tubular article as a stent with a pattern of perforations therein.
23. A process as in claim 22 wherein the tubular article formed with said pattern of perforations before said radially expanding step b).
24. A process as in claim 22 wherein the tubular article formed with said pattern of perforations after said annealing step c).
25. A process as in claim 22 further comprising at least one time repeating steps b) and c) on said tubular article.
26. A process as in claim 22 wherein the tubular article is formed of thermoplastic polymer material.
27. A process as in claim 26 wherein the step b) is performed at a temperature below the glass transition temperature of the polymer material.
28. A process as in claim 22 wherein the tubular article is made of biodegradable polymer material.