Methods for delivering, repositioning and/or retrieving self-expanding stents

Claim 2

1 . A method of delivering a shape memory stent having a transition temperature at or below body temperature to, and deploying the stent at a diseased tubular area in the body, comprising the steps of: mounting the shape memory stent in a collapsed condition on a thermal transfer device coupled to a catheter assembly, said thermal transfer device including a chamber having an outer transfer thermal wall, such that the heat transfer wall is in local heat transfer relationship with the stent; delivering the stent in said collapsed condition on said thermal transfer device to a region of the diseased tubular area in the body; infusing a flow of cooling thermal fluid into said chamber, commencing at least as early as the time the stent in its collapsed condition on the thermal transfer device has been delivered to a region of the diseased tubular area; if necessary, adjusting the position of the stent in said collapsed condition on said thermal transfer device in said narrowing tubular area; controlling the expansion of said stent into supporting engagement with the wall of the diseased tubular area by adjusting the temperature and/or rate of the inflow of cooling thermal fluid into said chamber.

Claim 3

2 . The method of claim 1 further including the steps of, during said delivery step, shielding the collapsed stent on the thermal transfer device to at least partially inhibit the heating of the stent to body temperature by the surrounding body tissue during said delivery step; and exposing the collapsed stent to the body upon substantial completion of said delivery step; and wherein said infusing step commences upon substantial completion of said delivery step and upon exposing of the collapsed stent to the body.

Claim 4

3 . The method of claim 2 wherein said shielding step comprises covering said collapsed stent on the thermal transfer device with a movable outer sheath situated in a forward position and forming part of said catheter assembly during delivery, and said exposing step comprises withdrawal of said outer sheath to a retracted position.

Claim 5

4 . The method of claim 1 wherein said in fusing step commences at the substantial commencement of said delivery step.

Claim 6

5 . The method of claim 1 including the further steps of, releaseably capturing said stent to said catheter assembly at the time of said mounting step; maintaining said capture of said stent to said catheter assembly during said delivery step; maintaining said capture of said stent to said catheter assembly during at least a part of said deploying step; and releasing said stent from capture to said catheter assembly after completion of at least a part of said deploying step.

Claim 7

6 . The method of claim 5 wherein said step of releasing said stent from capture to said catheter assembly commences substantially upon completion of said deploying step.

Claim 8

7 . The method of claim 5 wherein said catheter assembly comprises a stent-capturing sheath having a distal end; at least one hook member affixed to said distal end of said stent-capturing sheath; and an outer sheath having a distal end movably positioned over said stent-capturing sheath; and wherein said releasing step comprises moving said outer sheath with respect to said stent-capturing sheath whereupon said distal end of said outer sheath cooperates with said at least one hook member to move the same to release said stent.

Claim 9

8 . The method of claim 5 wherein said thermal transfer device comprises a balloon expandable and collapsible between expanded and collapsed conditions.

Claim 10

9 . The method of claim 8 wherein subsequent to the step of deploying said stent into supporting engagement with the wall of the diseased tubular area, performing a balloon angioplasty by expanding said balloon to engage said deployed stent and forcefully urge said stent against the wall of the diseased tubular area.

Claim 11

10 . The method of claim 9 wherein said catheter assembly comprises inflow passage means through which cooling thermal fluid is infused into said chamber during said infusing step and outflow passage means for providing a controllable outflow of cooling thermal fluid from said chamber, and wherein said step of performing an angioplasty by expanding the balloon comprises expanding the balloon by inflation under pressure by infusing fluid under pressure into said chamber and controlling the outflow of the fluid from said chamber to inflatingly expand said balloon under internal pressure into an expanded condition to engage said deployed stent and forcefully urge said stent against the wall of the narrowing tubular area.

Claim 12

11 . The method of claim 10 wherein said step of performing an angioplasty further comprises, in conjunction with said inflation of the balloon, actuating mechanical means coupled to said balloon for mechanically expanding the balloon into an expanded condition to engage said deployed stent and forcefully urge said stent against the wall of the diseased tubular area.

Claim 13

12 . The method of claim 8 wherein said releasing step comprises releasing said stent from capture to said catheter assembly by means activated by expansion of said balloon.

Claim 14

13 . The method of claim 11 wherein said catheter assembly comprises an inner core catheter and a relatively movable outer core catheter situated over said inner core catheter, said outer core catheter having a distal end which is situated proximally of the distal end of said inner core catheter so that projecting portion of said inner core catheter extends beyond said distal end of said outer core catheter, and a wire frame comprising a plurality of wires, each wire having one end affixed to a distal end of said projecting portion of said inner core catheter, another end affixed to the distal end of said outer core catheter, and a mid-region attached to said expandable balloon; and wherein said actuating step comprises moving said inner and outer core catheters with respect to each other to bend said wires in an outward direction and thereby expand said balloon.

Claim 15

14 . A method of delivering a shape memory stent having a transition temperature at or below body temperature to, and deploying the stent at, a diseased tubular area within the body, comprising the steps of: mounting the shape memory stent in a collapsed condition on an inflatable balloon in a collapsed condition coupled to a catheter assembly, said balloon having a chamber and having an outer heat transfer wall, such that the heat transfer wall is in local heat transfer relationship with the stent; delivering the stent in said collapsed condition on said collapsed balloon to a region of the diseased tubular area in the body; commencing a circulating flow into and from said chamber of said balloon at least as early as the time the stent in its collapsed condition on the collapsed balloon has been delivered to a region of the diseased tubular area; said circulating flow comprising infusing a flow of cooling thermal fluid from a proximal end of the catheter assembly into said chamber of said balloon, and withdrawing a flow of cooling thermal fluid from said chamber of said balloon to the proximal end of the catheter assembly; if necessary, adjusting the position of the stent in said collapsed condition on said collapsed balloon in said diseased tubular area; controlling the expansion of said stent into supporting the engagement of the wall of the diseased tubular area by adjusting the temperature and/or rate of the inflow of cooling thermal fluid into said chamber.

Claim 16

14 . A method of delivering a shape memory stent having a transition temperature at or below body temperature to, and deploying the stent at, a diseased tubular area within the body, comprising the steps of: mounting the shape memory stent in a collapsed condition on an inflatable balloon in a collapsed condition coupled to a catheter assembly, said balloon having a chamber and having an outer heat transfer wall, such that the heat transfer wall is in local heat transfer relationship with the stent; delivering the stent in said collapsed condition on said collapsed balloon to a region of the diseased tubular area in the body; commencing a circulating flow into and from said chamber of said balloon at least as early as the time the stent in its collapsed condition on the collapsed balloon has been delivered to a region of the diseased tubular area; said circulating flow comprising infusing a flow of cooling thermal fluid from a proximal end of the catheter assembly into said chamber of said balloon, and withdrawing a flow of cooling thermal fluid from said chamber of said balloon to the proximal end of the catheter assembly; if necessary, adjusting the position of the stent in said collapsed condition on said collapsed balloon in said diseased tubular area; controlling the expansion of said stent into supporting the engagement of the wall of the diseased tubular area by adjusting the temperature and/or rate of the inflow of cooling thermal fluid into said chamber.

Claim 17

15 . The method of claim 14 wherein subsequent to the step of deploying said stent into supporting engagement with the wall of the diseased tubular area, performing a balloon angioplasty by expanding said balloon into an expanded condition to engage said deployed stent, and forcefully urging said stent against the wall of the diseased tubular area; and wherein said catheter assembly comprises inflow passage means through which cooling thermal fluid is infused into said chamber during said infusing step and outflow passage means for providing a controllable outflow of cooling thermal fluid from said chamber, and wherein said step of performing an angioplasty by expanding the balloon comprises expanding the balloon by inflation under pressure by infusing fluid under pressure into said chamber and controlling the outflow of the fluid from said chamber to inflatingly expand said balloon under internal pressure into an expanded condition to engage said deployed stent and forcefully urge said stent against the wall of the narrowing tubular area.

Claim 18

16 . The method of claim 15 wherein said step of performing an angioplasty further comprises, in conjunction with said inflatingly expanding the balloon, actuating mechanical means coupled to said balloon for mechanically expanding the balloon into an expanded condition to engage said deployed stent and forcefully urge said stent against the wall of the diseased tubular area.

Claim 19

17 . The method of claim 16 wherein said catheter assembly comprises an inner core catheter and relatively movable outer core catheter situated over said inner core catheter, said outer core catheter having a distal end which is situated proximally of the distal end of said inner core catheter so that projecting portion of said inner core catheter extends beyond said distal end of said outer core catheter, and a wire frame comprising a plurality of wires, each wire having one end affixed to a distal end of said projecting portion of said inner core catheter, another end affixed to the distal end of said outer core catheter, and a central region attached to said expandable balloon; and wherein said actuating step comprises moving said inner and outer core catheters with respect to each other to bend said wires in an outward direction and thereby expand said balloon.

Claim 20

18 . The method of claim 14 including the further steps of, releasably capturing said stent to said catheter assembly at the time of said mounting step; maintaining said capture of said stent to said catheter assembly during said delivery step; maintaining said capture of said stent to said catheter assembly during at least a part of said deploying step; and releasing said stent from capture to said catheter assembly after completion of at least part of the deployment step.

Claim 21

19 . The method of claim 18 wherein said releasing step comprises releasing said stent from capture to said catheter assembly by means activated by expansion of said balloon.

Claim 22

20 . The method of claim 18 wherein said step of releasing said stent from capture to said catheter assembly commences substantially upon completion of said deploying step.

Claim 23

21 . The method of claim 18 wherein said catheter assembly comprises a stent-capturing sheath having a distal end; at least one hook member affixed to said distal end of said stent-capturing sheath; and an outer sheath having a distal end movably positioned over said stent-capturing sheath; and wherein said releasing step comprises moving said outer sheath with respect to said stent-capturing sheath whereupon said distal end of said outer sheath cooperates with said at least one hook member to move the same to release said sheath.

Claim 24

22 . A method of delivering a shape memory stent having a transition temperature greater than body temperature to, and deploying the stent at, a diseased tubular area within the body, comprising the steps of: mounting the shape memory stent in a collapsed condition on a thermal transfer device coupled to a catheter assembly, said thermal transfer device including a chamber having thermal transfer wall, such that the heat transfer wall is in local heat transfer relationship with the stent; delivering the stent is said collapsed condition on said thermal transfer device to a region of the diseased tubular area in the body; controlling the expansion of said stent into supporting engagement with the wall of the diseased tubular area by infusing a flow of heating thermal fluid into said chamber, commencing only after the time the stent in the collapsed position on the thermal transfer device has been delivered to a region of the diseased tubular area.

Claim 25

22 . A method of delivering a shape memory stent having a transition temperature greater than body temperature to, and deploying the stent at, a diseased tubular area within the body, comprising the steps of: mounting the shape memory stent in a collapsed condition on a thermal transfer device coupled to a catheter assembly, said thermal transfer device including a chamber having thermal transfer wall, such that the heat transfer wall is in local heat transfer relationship with the stent; delivering the stent is said collapsed condition on said thermal transfer device to a region of the diseased tubular area in the body; controlling the expansion of said stent into supporting engagement with the wall of the diseased tubular area by infusing a flow of heating thermal fluid into said chamber, commencing only after the time the stent in the collapsed position on the thermal transfer device has been delivered to a region of the diseased tubular area.

Claim 26

23 . A method of delivering a shape memory stent having a transition temperature at or below body temperature to, and deploying the stent at, a diseased tubular area in the body comprising the steps of: mounting the shape memory stent in a collapsed condition on an inflatable balloon in a collapsed condition coupled to a catheter assembly, said balloon having a chamber having an outer thermal transfer wall, such that the thermal transfer wall is in local heat transfer relationship with the stent; delivering the stent in said collapsed condition on said collapsed balloon to a region of the narrowing tubular area in the body; commencing a circulating flow into and from said balloon at least as early as the time the stent in its collapsed condition on the collapsed balloon has been delivered to a region of the diseased tubular area, said circulating flow comprising an inflow of cooling thermal fluid from a proximal end of the catheter assembly into said chamber of said balloon, and an outflow from the chamber of said balloon to the proximal end of the catheter assembly; if necessary, adjusting the position of the stent in said collapsed condition on said balloon in said diseased tubular area; controlling the expansion of the stent into supporting engagement with the wall of the diseased tubular area by adjusting the rate and/or the temperature of the inflow of cooling thermal fluid into said chamber; and during said controlled expansion step, at least partially expanding the balloon.

Claim 27

23 . A method of delivering a shape memory stent having a transition temperature at or below body temperature to, and deploying the stent at, a diseased tubular area in the body comprising the steps of: mounting the shape memory stent in a collapsed condition on an inflatable balloon in a collapsed condition coupled to a catheter assembly, said balloon having a chamber having an outer thermal transfer wall, such that the thermal transfer wall is in local heat transfer relationship with the stent; delivering the stent in said collapsed condition on said collapsed balloon to a region of the narrowing tubular area in the body; commencing a circulating flow into and from said balloon at least as early as the time the stent in its collapsed condition on the collapsed balloon has been delivered to a region of the diseased tubular area, said circulating flow comprising an inflow of cooling thermal fluid from a proximal end of the catheter assembly into said chamber of said balloon, and an outflow from the chamber of said balloon to the proximal end of the catheter assembly; if necessary, adjusting the position of the stent in said collapsed condition on said balloon in said diseased tubular area; controlling the expansion of the stent into supporting engagement with the wall of the diseased tubular area by adjusting the rate and/or the temperature of the inflow of cooling thermal fluid into said chamber; and during said controlled expansion step, at least partially expanding the balloon.

Claim 28

24 . The method of claim 23 wherein said step of expanding the balloon comprises controlling a circulating flow of fluid to and from the chamber of said balloon.

Claim 29

25 . The method of claim 24 wherein said step of controlling the circulating flow comprises controllably occluding said outflow from said chamber.

Claim 30

26 . The method of claim 24 wherein said expansion fluid comprises said thermal transfer fluid.

Claim 31

27 . The method of claim 24 wherein said step of expanding the balloon comprises expanding a frame assembly on said catheter assembly and to which said balloon is attached.

Claim 32

28 . The method of claim 27 wherein the catheter assembly comprises an inner core catheter and a relatively moveable outer core catheter situated over said inner core catheter, said outer core catheter having a distal end which is situated proximally of the distal end of said inner core catheter so that a projecting portion of said inner core catheter extends beyond said distal end region of said outer core catheter, and wherein said frame assembly comprises a plurality of wires, each wire having one end fixed to a distal end of said projecting portion of said inner core catheter, another end fixed to the distal end of said outer core catheter, and a central region attached to said expandable balloon.

Claim 33

29 . The method of claim 23 wherein subsequent to the step of deploying said stent into supporting engagement with the wall of the narrow tubular area, performing a balloon angioplasty by expanding said balloon into an expanded condition to engage said deployed stent and forcefully urge said stent against the wall of a narrow tubular area.

Claim 34

30 . The method of claim 29 wherein said step of performing an angioplasty by expanding the balloon comprises expanding the balloon by inflation under pressure by infusing a fluid under pressure into said chamber of said balloon and restricting the outflow of the fluid from said chamber.

Claim 35

31 . The method of claim 30 wherein said catheter assembly comprises an expandable frame assembly to which said balloon is attached to said catheter assembly, and wherein said step of performing an angioplasty further includes expanding said frame assembly on the catheter assembly.

Claim 36

32 . The method of claim 23 wherein during said mounting step, releaseably capturing said stent in said collapsed condition to said catheter assembly by capturing means moveably affixed to said catheter assembly and coupled to said balloon; and wherein said step of expanding the balloon during deployment causes movement of said capturing means to maintain connection between said catheter assembly and said stent as said stent expands; and wherein subsequent to deployment, releasing said capturing means from said stent by collapsing said balloon.

Claim 37

33 . A method of delivering a shape memory stent to, and deploying the stent at, a diseased tubular area in the body, comprising the steps of: mounting a stent in a collapsed condition on a thermal transfer device coupled to a catheter assembly, said thermal transfer device including a thermal transfer surface such that the thermal transfer surface is in local heat transfer relationship with the stent; delivering the stent in its collapsed condition on the thermal transfer device to a region of the diseased tubular area in the body; after delivery, adjusting the temperature of the thermal transfer surface to adjust the temperature of the stent in local thermal transfer relationship to control the expansion of said stent to an expanded condition whereupon the stent is deployed.

Claim 38

33 . A method of delivering a shape memory stent to, and deploying the stent at, a diseased tubular area in the body, comprising the steps of: mounting a stent in a collapsed condition on a thermal transfer device coupled to a catheter assembly, said thermal transfer device including a thermal transfer surface such that the thermal transfer surface is in local heat transfer relationship with the stent; delivering the stent in its collapsed condition on the thermal transfer device to a region of the diseased tubular area in the body; after delivery, adjusting the temperature of the thermal transfer surface to adjust the temperature of the stent in local thermal transfer relationship to control the expansion of said stent to an expanded condition whereupon the stent is deployed.

Claim 39

34 . The method of claim 33 wherein the shape memory stent has a transition temperature at or below body temperature, and wherein said temperature adjusting step comprises raising the temperature of the thermal transfer surface from a temperature below body temperature to allow the temperature of the stent to warm naturally to body temperature.

Claim 40

35 . The method of claim 33 wherein the shape memory stent has a transition temperature above body temperature, and wherein said temperature adjusting step comprises raising the temperature of the thermal transfer surface from body temperature to heat the stent to at least the transition temperature.

Claim 41

36 . The method of claim 33 wherein said temperature adjusting step comprises adjusting the temperature and/or rate of inflow of cooling thermal fluid into a chamber of said thermal transfer device.

Claim 42

37 . The method of claim 36 wherein said transfer device includes electrical heating wires in the chamber and said temperature adjusting step comprises adjusting the current flow through the heating wires.

Claim 43

38 . The method of claim 36 wherein said temperature adjusting step comprises directing ultrasonic energy into the chamber.

Claim 44

39 . The method of claim 36 wherein said temperature adjusting step comprises directing laser energy into the chamber.

Claim 45

40 . The method of claim 33 wherein said temperature adjusting step comprises directly controlling the temperature of the thermal transfer surface.

Claim 46

41 . The method of claim 40 wherein the thermal transfer surface includes conductive heating wires and wherein said step of directly controlling the temperature of the thermal transfer surface comprises adjusting the current flowing through said heating wires.

Claim 47

42 . The method of claim 40 said step of directly controlling the temperature of the thermal transfer surface comprises directing laser energy onto said thermal transfer surface.

Claim 48

43 . The method of claim 36 wherein said inflow of thermal fluid comprises circulating thermal fluid from the proximal end of the catheter assembly into the chamber and from the chamber to the proximal end of the catheter assembly.

Claim 49

44 . The method of claim 33 including the further step of capturing the stent to the catheter assembly during delivery, and releasing the stent from the catheter assembly during expansion or upon completion of expansion.

Claim 50

45 . The method of claim 33 wherein at least as early as completion of delivery and prior to the deployment, said step of adjusting the temperature of the thermal transfer surfaces comprises cooling the thermal transfer surface.

Claim 51

46 . A method of capturing a two-way shape memory stent having first and second transition temperatures which is already deployed in supporting engagement with a vessel wall at a first position for repositioning or retrieval comprising the steps of: providing an expandable and collapsible thermal transfer device in a collapsed condition on a catheter assembly, said expandable thermal transfer device including a chamber having a thermal transfer wall; introducing said expandable thermal transfer device in its collapsed condition on said catheter assembly into the lumen of the deployed stent; expanding the expandable thermal transfer device until its thermal transfer wall is in local thermal transfer relationship with the deployed stent; circulating a cooling thermal fluid from a proximal end region of said catheter assembly into said chamber of said expandable thermal transfer device and from said chamber of said thermal transfer device to said proximal end region of said catheter assembly to thereby cool said deployed stent in local thermal transfer relationship with said thermal transfer wall to cause the temperature of the stent to decrease to or below the second transition temperature to thereby become at least partially collapsed, soft and pliable; capturing said at least partially collapsed and softened stent by stent-capturing means to capture the stent to the catheter assembly.

Claim 52

46 . A method of capturing a two-way shape memory stent having first and second transition temperatures which is already deployed in supporting engagement with a vessel wall at a first position for repositioning or retrieval comprising the steps of: providing an expandable and collapsible thermal transfer device in a collapsed condition on a catheter assembly, said expandable thermal transfer device including a chamber having a thermal transfer wall; introducing said expandable thermal transfer device in its collapsed condition on said catheter assembly into the lumen of the deployed stent; expanding the expandable thermal transfer device until its thermal transfer wall is in local thermal transfer relationship with the deployed stent; circulating a cooling thermal fluid from a proximal end region of said catheter assembly into said chamber of said expandable thermal transfer device and from said chamber of said thermal transfer device to said proximal end region of said catheter assembly to thereby cool said deployed stent in local thermal transfer relationship with said thermal transfer wall to cause the temperature of the stent to decrease to or below the second transition temperature to thereby become at least partially collapsed, soft and pliable; capturing said at least partially collapsed and softened stent by stent-capturing means to capture the stent to the catheter assembly.

Claim 53

47 . The method of claim 46 wherein said expandable and collapsible thermal transfer device comprises a balloon.

Claim 54

48 . The method of claim 46 wherein said step of expanding said thermal transfer device comprises actuating a mechanical frame assembly at said distal end of said catheter assembly coupled to said thermal transfer device until said heat transfer wall of said thermal transfer device is in local thermal transfer relationship with said deployed stent.

Claim 55

49 . The method of claim 48 wherein said catheter assembly comprises an inner core catheter and a relatively movable outer core catheter situated over said inner core catheter, said outer core catheter having a distal end which is situated proximally of the distal end of said inner core catheter so that a projecting portion of said inner core catheter extends beyond said distal end of said outer core catheter, and a wire frame comprising a plurality of wires, each wire having one end affixed to a distal end of said projecting portion of said inner core catheter, another end affixed to the distal end of said outer core catheter, and a central region attached to said expandable balloon; and wherein said actuating step comprises moving said inner and outer core catheters with respect to each other to bend said wires in an outward direction and thereby expand said balloon.

Claim 56

50 . The method of claim 46 including the further step of partially collapsing said thermal transfer device after said softened stent has been captured by said stent capturing means and wherein said stent remains in constant local thermal transfer relationship with said thermal transfer wall of said thermal transfer device.

Claim 57

51 . The method of claim 50 wherein said catheter assembly comprises an inner core catheter and a relatively movable outer core catheter situated over said inner core catheter, said outer core catheter having a distal end which is situated proximally of the distal end of said inner core catheter so that projecting portion of said inner core catheter extends beyond said distal end of said outer core catheter, and a wire frame comprising a plurality of wires, each wire having one end affixed to a distal end of said projecting portion of said inner core catheter, another end affixed to the distal end of said outer core catheter, and a central region attached to said expandable balloon; and wherein said actuating step comprises moving said inner and outer core catheters with respect to each other to bend said wires in an outward direction and thereby expand said thermal transfer device.

Claim 58

52 . The method of claim 48 wherein said thermal fluid circulating step occurs at a low pressure during said balloon expansion step.

Claim 59

53 . The method of claim 46 wherein said step of cooling said deployed stent is conducted to cause one portion of the stent to collapse before collapse of the entire stent.

Claim 60

54 . The method of claim 46 comprising the further step of, after capturing the stent, retrieving the stent from the body.

Claim 61

55 . The method of claim 54 wherein said catheter assembly includes a stent-receiving sheath, and wherein said step of retrieving said stent from the body comprises the steps of: fully collapsing said thermal transfer device; positioning the softened stent into said stent-receiving sheath; and withdrawing the catheter assembly from the body.

Claim 62

56 . The method of claim 46 comprising the further step of, after capturing the stent, repositioning the stent in a supporting engagement with a vessel wall at a second position.

Claim 63

57 . The method of claim 56 wherein said catheter assembly includes a stent-receiving sheath, said two-way shape memory stent has a first transition temperature at or below temperature and wherein said step of repositioning said stent at a second position comprises the steps of: fully collapsing said thermal transfer device; positioning the softened stent into said stent-receiving sheath into local thermal transfer relationship with said thermal transfer wall of said thermal transfer device; repositioning the catheter assembly in the body so that said stent, situated in said stent-receiving sheath, is repositioned at said second position; and exposing the stent from within the stent-receiving sheath to expose the stent to body temperature, whereupon said stent is heated by the body and expands into supporting engagement with the vessel wall at said second position.

Claim 64

58 . The method of claim 56 wherein said step of repositioning said stent at a second position comprises, while maintaining circulation of said cooling thermal fluid, repositioning the catheter assembly in the body so that the stent is repositioned at said second positioning, and terminating the circulation of the cooling thermal fluid.

Claim 65

59 . The method of claim 57 wherein said step of repositioning said stent comprises the further step of after exposing the stent from the stent-receiving sheath, releasing the stent from the stent-capturing means to free the stent from the catheter assembly.

Claim 66

60 . The method of claim 56 wherein said catheter assembly includes a stent-receiving sheath, said two-way shape memory stent has a first transition temperature greater than body temperature, and wherein said step of repositioning the stent at a second position comprises the steps of: fully collapsing said thermal transfer device; drawing the softened stent into said stent-receiving sheath by said stent-capturing means into local thermal transfer relationship with said thermal transfer wall of said thermal transfer device; repositioning the catheter assembly in the body so that said stent situated in said stent-receiving sheath is repositioned at said second position; exposing the stent from the stent-receiving sheath; if necessary adjusting the position of the system within the diseased area; circulating a heating thermal fluid from a proximal end region of said catheter assembly into said chamber of said thermal transfer device and from said chamber of said proximal end region of said catheter assembly to thereby heat said stent in local thermal transfer relationship with said thermal transfer wall to cause the temperature of the stent to increase to the first transition temperature to thereby expand into supporting engagement with the vessel wall at the second position; and releasing the stent from said capturing means.

Claim 67

61 . A method of capturing a two-way shape memory stent which is already deployed in supporting engagement with a vessel wall, for repositioning or retrieval comprising the steps of: providing a thermal transfer device on a catheter assembly, said thermal transfer device having a thermal transfer surface; introducing the thermal transfer device into the lumen of the deployed stent; positioning the thermal transfer device until the thermal transfer surface is in local thermal transfer relationship with the deployed stent; reducing the temperature of the thermal transfer device to thereby cool said deployed stent in local heat transfer relationship with said thermal transfer surface to cause the temperature of the stent to decrease to or below the second transition temperature to thereby become at least partially collapsed, soft and pliable, and separate from the vessel wall and; capturing the at least partially collapsed and softened stent by stent-capturing means to capture the stent to the catheter assembly.

Claim 68

61 . A method of capturing a two-way shape memory stent which is already deployed in supporting engagement with a vessel wall, for repositioning or retrieval comprising the steps of: providing a thermal transfer device on a catheter assembly, said thermal transfer device having a thermal transfer surface; introducing the thermal transfer device into the lumen of the deployed stent; positioning the thermal transfer device until the thermal transfer surface is in local thermal transfer relationship with the deployed stent; reducing the temperature of the thermal transfer device to thereby cool said deployed stent in local heat transfer relationship with said thermal transfer surface to cause the temperature of the stent to decrease to or below the second transition temperature to thereby become at least partially collapsed, soft and pliable, and separate from the vessel wall and; capturing the at least partially collapsed and softened stent by stent-capturing means to capture the stent to the catheter assembly.

Claim 69

62 . The method of claim 61 wherein said thermal transfer device is expandable and collapsible, and wherein said thermal transfer device is introduced into the lumen of the deployed stent in its collapsed condition, and wherein said positioning step comprises expanding the thermal transfer device.

Claim 70

63 . The method of claim 61 including the additional step of positioning the captured stent into an outer sheath.

Claim 71

64 . The method of claim 63 including the further step of removing the outer sheath containing the stent from the body to retrieve the stent.

Claim 72

65 . The method of claim 63 including the further step of repositioning the outer sheath containing the stent at a new location in the vessel and deploying the stent at said new position.