Tissue supporting devices

• US 6,451,052 B1
• Filed: 10/14/1998
• Issued: 09/17/2002
• Est. Priority Date: 05/19/1994
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Brown, Brian J., Vrba, Anthony C., Euteneuer, Charles L., Burmeister, Paul H., Fordenbacher, Paul J.
• Primary Examiner(s): Prebilic, Paul B.
• Application Number:
  US09/172,590
• Time in Patent Office: 1,434 Days
• Field of Search: 623/1.16, 623/1.17, 623/1.18, 623/1.19, 623/1.2, 623/1, 623/44, 623/23.7, 606/195, 606/198
• US Class Current: 623/1.16
• CPC Class Codes: A61F 2/844 folded prior to deployment
• 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 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 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/9155 Adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2250/0029 differing in bending or flexure capacity
• CPC Class Codes: A61F 2250/0042 differing in shape-memory transition temperatures, e.g. in martensitic transition temperature, in austenitic transition temperature
• CPC Class Codes: A61L 31/022 Metals or alloys

Abstract

A new multiple component stent arrangement which allows for initial self-expansion and subsequent deformation to a final enlarged size. These tissue supporting devices are generally cylindrical or tubular. They have at least one component which is deformable, by an external force, to maintain further expansion.

Claims

1. A tissue supporting device comprising a constrainable, self-expanding member of generally tubular shape, said member comprising a first layer of a resilient self-expandable material and a second layer of a deformable and substantially less resilient material than the first layer, said second layer being deformable by an external force but being non-self-expandable;

the member being constrainable to a deployable diameter in preparation for insertion into a patient;

the member being self-expanding when unconstrained to an initially deployed diameter due to the transformation of the first layer from a martensitic to an austenitic state;

the first and second layers being affixed to each other or braided;

the first and second layers being so associated with respect to each other such that the device may be further expanded due to the deformability of the second layer by an external force to radially enlarge the member to an enlarged self sustained fully deployed diameter for providing tissue support.

2. The device of claim 1 wherein the first and second portions are of metal.

6. The device of claim 1 wherein the first and second portions are of a shape memory alloy.

16. The tissue supporting device of claim 1 wherein the first and second portions are mechanically joined, welded together, bonded together or joined by vapor deposition or ion beam deposition of the first portion onto the second portion.

3. A tissue supporting device comprising a constrainable, self-expanding member of generally tubular shape, said member comprising a first layer of a resilient self-expandable material and a second layer of a deformable and substantially less resilient material than the first layer, said second layer being deformable by an external force but being non-self-expandable;

said first and second layers being discrete portions in the circumference of said tissue supporting device;

the member being constrainable to a deployable diameter in preparation for insertion into a patient;

the member being self-expanding when unconstrained to an initially deployed diameter due to the transformation of the first layer from a martensitic to an austenitic state;

the first and second layers being so associated with respect to each other such that the device may be further expanded due to the deformability of the second layer by an external force to radially enlarge the member to an enlarged fully deployed diameter for providing tissue support.

4. A tissue supporting device comprising a constrainable, self-expanding member of generally tubular shape, said member comprising a first layer of a resilient self-expandable material and a second layer of a deformable and substantially less resilient material than the first layer, said second layer being deformable by an external force but being non-self-expandable;

said first and second layers being comprised of a shape memory alloy;

the member being constrainable to a deployable diameter in preparation for insertion into a patient;

the member being self-expanding when unconstrained to an initially deployed diameter due to the transformation of the first layer from a martensitic to an austenitic state;

the first and second layers being so associated with respect to each other such that the device may be further expanded due to the deformability of the second layer by an external force to radially enlarge the member to an enlarged fully deployed diameter for providing tissue support.

5. A tissue supporting device comprising a constrainable, self-expanding member of generally tubular shape, said member comprising a first layer of a resilient self-expandable material and a second layer of a deformable and substantially less resilient material than the first layer, wherein the first and second layers are of shape memory alloy, austenite and martensite, respectively, said second layer being deformable by an external force but being non-self-expandable;

the member being constrainable to a deployable diameter in preparation for insertion into a patient;

the member being self-expanding when unconstrained to an initially deployed diameter due to the transformation of the first layer from a martensitic to an austenitic state;

the first and second layers being affixed to each other or braided;

the first and second layers being so associated with respect to each other such that the device may be further expanded due to the deformability of the second layer by an external force to radially enlarge the member to an enlarged self sustained fully deployed diameter for providing tissue support.

7. A tissue supporting device comprising a constrainable, self-expanding member of generally tubular shape further comprising a predetermined fabricated diameter;

said member comprising a first layer of resilient self-expandable material and a second layer of a deformable and substantially less resilient material than the first layer, said second layer being deformable by an external force but being non-self-expandable;

the member being constrainable to a deployable diameter in preparation for insertion into a patient;

the member being self-expanding when unconstrained to an initially deployed diameter due to the resiliency of the first layer;

the first and second layers being so associated with respect to each other such that the device may be further expanded due to the deformability of the second layer by an external force to radially enlarge the member to an enlarged fully deployed diameter for providing tissue support;

wherein at normal body temperatures the first layer is comprised of a shape-memory, superelastic austenite alloy layer and the second layer is comprised of a shape-memory, martensite alloy layer;

the superelastic austenite alloy layer having a transition temperature from martensite to austenite less than body temperature while the martensite alloy layer has a transition temperature from martensite to austenite greater than body temperature, the martensite alloy layer and the superelastic austenite alloy layer being constructed, arranged and associated with respect to each other such that the two alloy layers act in combination to allow constraint of the stent to a deployment diameter smaller than the predetermined fabricated diameter, and upon transformation of the first layer from martensite back to austenite to self-expand the stent back to a self-expanded diameter that is about the predetermined fabricated diameter at temperatures in excess of the transition temperature of the first layer, the shape memory of the superelastic austenite first layer tending to form the stent to a larger diameter than the predetermined fabricated diameter and the self-expanded diameter due to its shape memory but being restrained therefrom by the second martensite alloy layer, wherein the first layer can be deformed by external force. along with the second layer to an enlarged stent diameter beyond that of the selfexpanded diameter.

8. The tissue supporting device of claim 7 wherein the first and second portions are in the form of layers in overlying relationship.

9. The tissue supporting device of claim 7 wherein the alloy composition is about 50Ni/50Ti atomic weight percent.

10. The tissue supporting device of claim 7 wherein the alloy composition is a cold worked alloy.

11. The tissue supporting device of claim 7 wherein the alloy composition is a prestrained alloy.

12. The tissue supporting device of claim 7 wherein the alloy composition exhibits cycle amnesia.

13. A permanent self-expanding stent for providing permanent tissue support, said stent having a generally tubular body of a predetermined fabricated diameter and being comprised, at about normal body temperatures, of a first layer comprised of a shape-memory, superelastic, austenite alloy and a second layer comprised of a shape memory, martensite alloy;

the shape-memory, superelastic austenite alloy layer having a transition temperature from martensite to austenite less than body temperature while the martensite alloy layer has a transition temperature from martensite to austenite greater than body temperature, the martensite alloy layer and superelastic austenite alloy layer being constructed, arranged and associated with respect to each other such that the two alloy layers act in combination to allow constraint of the stent to a deployment diameter smaller than the predetermined fabricated diameter and upon transformation of the first layer from martensite back to austenite to self-expand the stent back to a self-expanded diameter that is about the predetermined fabricated diameter at temperatures in excess of the transition temperature of the first layer, the shape memory of the superelastic austenitic first layer tending to form the stent to a larger diameter than the self-expanded diameter and the predetermined fabricated diameter due to its shape memory but being restrained therefrom by the second martensitic alloy layer, wherein the first layer can be deformed by external force along with the second layer to an enlarged stent diameter beyond that of the self-expanded diameter.

14. A permanent self-expanding stent having a generally tubular body of a predetermined fabricated diameter comprised, at about normal body temperatures, of a shape-memory, superelastic, austenite alloy layer and a shape memory, martensite alloy layer, the superelastic austenite alloy layer having a transition temperature from martensite to austenite less than body temperature while the martensite alloy layer has a transition temperature from martensite to austenite greater than body temperature, the martensite alloy layer and superelastic austenite alloy layer being constructed, arranged and associated with respect to each other in comprising the stent such that the two alloy layers act in combination to allow, upon transformation of the austenite alloy layer to martensite at a temperature below the transition temperature, constraint of the stent to a deployment diameter smaller than the predetermined fabricated diameter and upon transformation of the austenite alloy layer from martensite back to austenite to self-expand the stent back to about the predetermined fabricated diameter at temperatures in excess of the transition temperature of the austenite superelastic layer, the shape memory of the superelastic austenite layer tending to form the stent to a larger diameter due to its shape memory but being restrained therefrom by the martensite alloy layer wherein the austenite alloy layer can be deformed by external force without plastic deformation along with the martensite layer to an enlarged stent diameter beyond that of the self-expanded diameter.

15. A permanent self-expanding stent having a generally tubular body of a predetermined fabricated diameter, comprised, at about normal body temperatures, of a shape-memory, superelastic, austenite phase layer and a shape memory, martensite phase layer, the superelastic austenite phase layer having a transition temperature from martensite to austenite less than body temperature while the martensite phase layer has a transition temperature from martensite to austenite greater than body temperature, the martensite phase layer and superelastic austenite phase layer being constructed, arranged and associated with respect to each other in comprising the stent such that the two layers act in combination to allow, upon transformation of the austenite phase layer to martensite, constraint of the stent to a deployment diameter smaller than the predetermined fabricated diameter and upon transformation of the austenite phase layer from martensite back to austenite to self-expand the stent back toward the predetermined fabricated diameter at temperatures in excess of the transition temperature of the austenite superelastic layer, the shape memory of the superelastic austenitic layer tending to form the stent to the fabricated diameter due to its shape memory but being restrained therefrom by the martensite layer wherein the austenite layer recovery back toward the fabricated diameter can be assisted by external force along with the deforming of the martensite layer without slip deformation to an enlarged stent diameter beyond that of the fabricated diameter.