Apparatus and method for dilatation of a body lumen and delivery of a prosthesis therein

• US 5,993,484 A
• Filed: 07/15/1998
• Issued: 11/30/1999
• Est. Priority Date: 10/23/1996
• Status: Expired due to Term

• Current Assignee: United States Surgical Corporation (Medtronic Plc)
• Original Assignee: United States Surgical Corporation (Medtronic Plc)
• Inventors: Shmulewitz, Ascher
• Primary Examiner(s): Dawson, Glenn K.
• Application Number:
  US09/116,091
• Time in Patent Office: 503 Days
• Field of Search: 606/1, 606/108, 606/159, 606/191-200, 623/1, 623/11, 623/12, 604/96-104
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/823 Stents, different from stent-grafts, adapted to cover an aneurysm

Abstract

Apparatus and methods are provided for first expanding a body lumen of a body vessel or organ and then deploying a prosthesis to maintain the lumen patent. The apparatus includes a catheter having a balloon member formed of a biocompatible material, a balloon cutting element, and a thermally activated shape memory alloy prosthesis disposed within the balloon. The prosthesis is formed of nickel-titanium alloy having a reduced diameter in the martensite phase, and an expanded diameter in the austenite phase. The balloon member is inflated using a first fluid having a temperature below the martensite transition temperature to expand the body lumen and a second fluid having a temperature sufficient to cause the prosthesis to transition to the expanded diameter, trapping the material of the balloon member against the body wall. A cutting device disposed on the catheter then severs balloon member to release the prosthesis.

Claims

1. Apparatus for dilating a body lumen and retaining the body lumen patent, which comprises:

an elongated member having a proximal end region and a distal end region and defining a longitudinal axis;

a balloon member disposed adjacent the distal end region for expanding an inner dimension of the body lumen;

a prosthesis at least partially disposed within the balloon member, the prosthesis having a first configuration of reduced dimension and a second configuration of expanded dimension; and

a cutting member mounted to the elongated member and being adapted to sever the balloon member from the distal end region of the elongated member.

2. The apparatus according to claim 1 wherein the cutting member includes an outer sheath disposed on the elongated member and having a cutting element adjacent a distal end of the outer sheath, the outer sheath adapted for longitudinal movement to sever the balloon member.

3. The apparatus according to claim 2 wherein the outer sheath is adapted to rotate during longitudinal movement thereof.

4. The apparatus according to claim 1 wherein the prosthesis comprises a shape memory alloy.

5. The apparatus according to claim 4 wherein the prosthesis has a martensite transition temperature about equal to body temperature.

6. The apparatus according to claim 4 wherein the prosthesis comprises a one-way thermally activated shape memory material.

7. The apparatus according to claim 4 wherein the prosthesis comprises a two-way thermally activated shape memory material.

8. The apparatus according to claim 1 wherein the prosthesis is adapted to retain the balloon member against the body lumen when the prosthesis is in the second configuration.

9. The apparatus according to claim 1 wherein the prosthesis comprises a plurality of pairs of substantially straight segments, each of the pairs connected by a U-shaped segment.

10. The apparatus according to claim 1 wherein the balloon member and the prosthesis are dimensioned and configured to form a fluid impermeable graft upon severing of the balloon member.

11. Apparatus for deploying a stent-graft in a body lumen, which comprises:

a catheter body having a proximal end region and a distal end region;

a balloon member comprising a biocompatible material disposed on the distal end region;

a stent confined within the balloon member, the stent having a first shape of reduced dimension and a second shape of expanded dimension; and

means for severing the balloon member from the distal end region of the catheter body when the stent is in the second shape such that at least a portion of the balloon member is captured between the stent and an inner wall of the body lumen.

12. The apparatus according to claim 11 wherein the means for severing the balloon comprises:

an outer sheath disposed on the catheter body, the outer sheath having a distal end; and

a cutting element disposed on the distal end.

13. The apparatus according to claim 11 wherein the stent comprises a shape memory alloy.

14. The apparatus according to claim 13 wherein the stent has a martensite transition temperature about equal to body temperature.

15. The apparatus according to claim 11 wherein the stent includes ends that are constrained by the balloon member when the stent is in the second shape, so that the biocompatible material is forced against the body lumen when the stent is in the second shape.

16. A method of dilating a body lumen and disposing a prosthesis within the body lumen, the method comprising the steps of:

providing an apparatus including an elongate member having a proximal end region and a distal end region, a balloon member formed of a biocompatible material disposed on the distal end region, a prosthesis at least partially disposed within the balloon member, the prosthesis having a first shape of reduced dimension and a second shape of expanded dimension;

inserting the distal end region of the elongate member to a desired position within the body lumen;

inflating the balloon member to expand the body lumen; and

expanding the prosthesis to the second shape within the balloon member;

severing the balloon member from the apparatus to deploy the prosthesis.

17. The method according to claim 16 wherein the apparatus includes means for severing the balloon member, and wherein the step of severing includes the step of actuating the severing means.

18. The method according to claim 17 wherein the means for severing includes a cutting element mounted with respect to the elongate member, and wherein the step of severing includes longitudinally moving the cutting element relative to the elongate member whereby a cutting edge of the cutting element severs the balloon member.

19. The method according to claim 16 wherein the step of providing further comprises providing an apparatus having a prosthesis formed of a thermally activated shape memory alloy.

20. The method according to claim 19 wherein the step of inflating comprises the step of introducing a fluid having a temperature below the transition temperature of the prosthesis into the balloon member to expand the balloon member.

21. The method according to claim 20 wherein the step of expanding comprises the step of introducing a fluid having at temperature above the transition temperature of the prosthesis into the balloon member.

22. Apparatus for maintaining patency of a body vessel, which comprises:

an elongated member defining a longitudinal axis and having proximal and distal ends, and being adapted to be positioned within a body vessel;

an expandable member mounted to the elongated member and expandable to engage inner wall portions of the body vessel; and

a prosthesis at least partially disposed within the expandable member, the prosthesis moveable from a contracted condition to an expanded condition wherein in the expanded condition the prosthesis is dimensioned to retain the expandable member against the inner wall portion of the body vessel to thereby maintain an inner dimension of a lumen of the body vessel.

23. The apparatus according to claim 22 further including a cutting member mounted to the elongated member to cut the expandable member to release at least a portion of the expandable member from the elongated member.

24. The apparatus according to claim 23 wherein the expandable member is an inflatable balloon membrane.

25. The apparatus according to claim 24 wherein the elongated member includes an inflation passageway to permit passage of inflation fluids to the balloon membrane to inflate the balloon membrane.

26. The apparatus according to claim 25 wherein the prosthesis is enclosed within the balloon membrane when in the contracted condition of the prosthesis.

27. The apparatus according to claim 26 wherein the cutting member is longitudinally moveable to cut the balloon membrane to release at least a portion of the balloon membrane and the prosthesis from the elongated member.

28. The apparatus according to claim 27 wherein the prosthesis comprises a thermally activated shape memory material.

29. An apparatus for maintaining the patency of a body vessel, which comprises:

a catheter body defining a longitudinal axis and having proximal and distal end portions, and having an inflation channel associated therewith for passage of inflation media;

a balloon member mounted adjacent the distal end portion of the catheter body and in communication with the inflation channel; and

a stent at least partially disposed within the balloon member and releasably mounted with respect to the catheter body, the stent comprising a shape memory material and being capable of moving from an initial condition to an expanded condition in response to a predetermined temperature level of inflation media introduced within the balloon member to thereby engage an inner wall portion of the body vessel to maintain the patency thereof.

30. The apparatus according to claim 29 further including a cutting member mounted with respect to the catheter body and actuable to sever the balloon member from the catheter body, to thereby release the stent within the body vessel.

31. The apparatus according to claim 30 wherein the stent and the balloon member are dimensioned and arranged such that upon actuation of the cutting member the stent retains at least a portion of the balloon member against the inner wall of the body vessel.

32. An apparatus for maintaining the patency of a body vessel, comprising a catheter defining a longitudinal axis and having proximal and distal end portions, and being at least partially positionable within a body vessel, the distal end portion having an expandable member mounted thereto and a stent at least partially disposed within the expandable member, the expandable member expandable to engage an inner wall of the body vessel to increase an inner dimension defined within the body vessel, the stent releasably mounted with respect to the catheter wherein upon movement to a deployed position thereof the stent is in supportive relationship with the inner wall of the body vessel to thereby maintain the patency of the body vessel.

33. A method for maintaining the patency of a body organ, comprising the steps of:

positioning an elongated member into a body passage, the elongated member including an inflatable membrane and a prosthesis at least partially disposed within the inflatable membrane;

inflating the inflatable membrane to cause engagement thereof with an inner wall portion of the body passage; and

expanding the prosthesis to cause engagement thereof with the inflatable membrane to maintain the inflatable membrane against the inner wall portion to thereby maintain the patency of the body passage.

34. The method according to claim 33 including the step of releasing the inflatable membrane and the prosthesis from the elongated member.

35. The method according to claim 34 including the step of removing the elongated member from the body passage thereby leaving the inflatable membrane and the prosthesis within the body organ.

36. The method according to claim 35 wherein the elongated member includes a cutting member associated therewith and wherein the step of releasing includes actuating the cutting member to sever at least a portion of the inflatable member from the elongated member.

37. The method according to claim 36 wherein the prosthesis comprises a thermally activated shape memory material and wherein the step of expanding includes subjecting the prosthesis to a temperature to cause the prosthesis to expand.

38. The method according to claim 37 wherein the elongated member includes an inflation channel in communication with the inflatable membrane and wherein the step of expanding includes introducing fluid through the inflation channel and into the inflatable membrane, the inflation fluid being at a temperature to cause the prosthesis to expand.

39. The method according to claim 38 wherein the inflatable membrane comprises a biocompatible material and wherein the step of expanding includes arranging the inflatable membrane to serve as a graft for the body organ.