Rotational atherectomy device with exchangeable drive shaft cartridge

• US 6,077,282 A
• Filed: 12/10/1997
• Issued: 06/20/2000
• Est. Priority Date: 10/27/1997
• Status: Expired due to Term

• Current Assignee: Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Shturman Cardiology Systems, Inc.
• Inventors: Shturman, Leonid, Morov, Georgiy
• Primary Examiner(s): Dawson, Glenn K.
• Application Number:
  US08/988,493
• Time in Patent Office: 923 Days
• Field of Search: 606/159, 606/167, 606/170, 606/180, 606/171, 606/169, 604/19, 604/22
• US Class Current: 606/159
• CPC Class Codes: A61B 17/320758 with a rotating cutting instrument, e.g. motor driven A61B17/320725, A61B17/32075 and A61B17/320783 take precedence; for removing intra-ocular material A61F9/00763; endoscopic rotatable cutting instruments A61B17/32002
• CPC Class Codes: A61B 2017/0046 with a releasable handle; with handle and operating part separable
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2017/00685 Archimedes screw
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: F16D 43/14 with centrifugal masses actuating the clutching members directly in a direction which has at least a radial component; with centrifugal masses themselves being the clutching members

Abstract

A rotational atherectomy device having a handle housing and an exchangeable drive shaft cartridge. The handle housing includes a rotatable prime mover carried by a prime mover carriage which is longitudinally movable with respect to the handle housing. The exchangeable drive shaft cartridge includes a cartridge housing, a longitudinally extendable tube, a catheter and a rotatable drive shaft which, near its distal end, has an abrasive tissue removal implement. The cartridge housing may be attached to and detached from the handle housing, the longitudinally extendable tube may be attached to and detached from the prime mover carriage, and the drive shaft together with its tissue removal implement may be attached to and detached from the prime mover, thereby permitting the exchangeable drive shaft cartridge to be selectively attached to and detached from the handle housing.

Claims

1. A rotational atherectomy device comprising:

a handle housing and an exchangeable drive shaft cartridge having a housing which is removably attachable to the handle housing;

a rotatable prime mover carried by a prime mover carriage which is disposed within the handle housing, the prime mover carriage being longitudinally movable with respect to the handle housing;

the exchangeable drive shaft cartridge including

a longitudinally extendable tube having a distal end portion carried by the cartridge housing and a proximal end portion which is removably attachable to the prime mover carriage for longitudinal movement therewith;

an elongated catheter having a proximal end portion which is carried by the cartridge housing; and

a rotatable flexible drive shaft having proximal, intermediate and distal portions, the proximal portion being attached to an elongated shank, the intermediate portion being disposed primarily within the tube and the catheter, and the distal portion extending distally from the catheter and having a tissue removal implement; and

a drive shaft attachment mechanism removably attaching the drive shaft to the prime mover, the drive shaft attachment mechanism comprising a prime mover socket carried by the prime mover and the elongated shank carried by the proximal end portion of the drive shaft, the shank being removably insertable into the socket, at least one of the shank and the socket being radially resilient;

whereby the cartridge housing may be attached to and detached from the handle housing, the longitudinally extendable tube may be attached to and detached from the prime mover carriage, and the drive shaft may be attached to and detached from the prime mover, thereby permitting the exchangeable drive shaft cartridge to be selectively attached to and detached from the handle housing.

2. The rotational atherectomy device of claim 1 wherein the prime mover includes a hollow prime mover shaft.

3. The rotational atherectomy device of claim 2 wherein the hollow shaft of the prime mover includes a recess for receiving the prime mover socket therein.

4. The rotational atherectomy device of claim 1 wherein the prime mover socket is radially resilient.

5. The rotational atherectomy device of claim 1 wherein the inner diameter of the socket is selected to provide a sufficiently tight interference fit with the shank so that, when the drive shaft is attached to the prime mover, the shank and the drive shaft both move longitudinally together with the socket and the prime mover when the prime mover is moved longitudinally with respect to the handle housing.

6. The rotational atherectomy device of claim 1 wherein the inner diameter of the socket is selected to provide a sufficiently tight interference fit with the shank so that, when the drive shaft is attached to the prime mover, the shank and the drive shaft both rotate together with the socket and the prime mover when the prime mover is rotated.

7. The rotational atherectomy device of claim 1 wherein the longitudinally extendable tube is comprised of two elongated telescopic tubes, one of them being a stationary telescopic tube carried by the cartridge housing, and the other being a movable telescopic tube which is carried by and is longitudinally movable with respect to the stationary telescopic tube, the movable telescopic tube being removably attachable to the prime mover carriage for longitudinal movement therewith.

8. The rotational atherectomy device of claim 7 further comprising a distal abutment surface defined by an element of a proximal end portion of the movable telescopic tube, the distal abutment surface being located distally of the shank and being positioned so that the shank abuts the distal abutment surface when the prime mover carriage is moved distally to insert the shank into the socket.

9. The rotational atherectomy device of claim 8 wherein the distal abutment surface defined by said element of the proximal end portion of the movable telescopic tube is a proximal surface of a bushing having a longitudinal lumen within which the drive shaft is disposed and may freely rotate, the bushing being secured to the movable telescopic tube distally of the shank.

10. The rotational atherectomy device of claim 7 wherein the elongated shank includes proximal and distal portions, the distal portion having a radially outwardly extending flange.

11. The rotational atherectomy device of claim 10 wherein the shank'"'"'s flange is generally annular.

12. The rotational atherectomy device of claim 10 further comprising a proximal abutment surface defined by an element of a proximal end portion of the movable telescopic tube, the proximal abutment surface being located proximally of the shank'"'"'s flange, the shank'"'"'s flange abutting the proximal abutment surface when the shank is being removed from the prime mover socket.

13. The rotational atherectomy device of claim 12 further comprising an abutment member secured to the proximal end portion of the movable telescopic tube, the abutment member including a flange, the proximal abutment surface defined by said element of the movable telescopic tube being a surface of such flange.

14. The rotational atherectomy device of claim 1 further comprising a tube attachment mechanism positioned to removably attach the longitudinally extendable tube to the prime mover carriage, the tube attachment mechanism including a resilient positioning mechanism for moving the prime mover carriage and the shank proximally with respect to the longitudinally extendable tube after the prime mover carriage has been advanced distally and attached to the longitudinally extendable tube and after pressure moving the prime mover carriage distally with respect to the longitudinally extendable tube has been released, the resilient positioning mechanism thereby spacing the shank away from an abutment surface defined by an element of the longitudinally extendable tube to permit free rotation of the shank with respect to the longitudinally extendable tube.

15. The rotational atherectomy device of claim 14 wherein the longitudinally extendable tube is comprised of two elongated telescopic tubes, one of them being a stationary telescopic tube carried by the cartridge housing, and the other being a movable telescopic tube which is carried by and is longitudinally movable with respect to the stationary telescopic tube, the movable telescopic tube being removably attachable to the prime mover carriage for longitudinal movement therewith.

16. The rotational atherectomy device of claim 15 further comprising distal and proximal abutment surfaces defined by elements of a proximal end portion of the movable telescopic tube, the distal abutment surface being positioned to abut the shank when the shank is being inserted into the prime mover socket and the proximal abutment surface being positioned to abut a flange carried by the shank when the shank is being removed from the prime mover socket, the distal abutment surface being spaced away from the shank by the resilient positioning mechanism after the prime mover carriage has been advanced distally and attached to the movable telescopic tube and after pressure moving the prime mover carriage distally with respect to the movable telescopic tube has been released.

17. The rotational atherectomy device of claim 15 wherein the resilient positioning mechanism comprises a resilient positioning ring having a radially inner portion and a radially outer portion.

18. The rotational atherectomy device of claim 17 wherein the resilient positioning ring is carried by the prime mover carriage, the radially outer portion of the positioning ring being secured against longitudinal movement with respect to the prime mover carriage, and the radially inner portion of the resilient ring being configured with respect to the prime mover carriage so that such inner portion of the ring resiliently deflects proximally when the prime mover carriage and resilient positioning ring are moved distally over the movable telescopic tube, the radially inner portion of the resilient ring at least partially returning to its non-deflected configuration and moving the prime mover carriage and the shank proximally with respect to the movable telescopic tube after pressure urging the prime mover carriage and the resilient positioning ring over the movable telescopic tube has been removed, thus spacing the shank away from the distal abutment surface defined by said element of the movable telescopic tube and permitting the shank to rotate freely with respect to the movable telescopic tube.

19. The rotational atherectomy device of claim 17 wherein the resilient positioning ring is carried by the movable telescopic tube, the radially inner portion of the positioning ring being secured against longitudinal movement with respect to the movable telescopic tube, and the radially outer portion of the resilient ring being configured so that such outer portion of the ring resiliently deflects distally when the prime mover carriage is moved distally over the resilient positioning ring secured to the movable telescopic tube, the radially outer portion of the resilient ring at least partially returning to its non-deflected configuration and moving the prime mover carriage and the shank proximally with respect to the movable telescopic tube after pressure urging the prime mover carriage over the resilient positioning ring has been removed, thus spacing the shank away from the distal abutment surface defined by said element of the movable telescopic tube and permitting the shank to rotate freely with respect to the movable telescopic tube.

20. The rotational atherectomy device of claim 15 wherein the resilient positioning mechanism includes a detent carried by the prime mover carriage and a spring positioned to urge the detent radially into a complementary groove formed in an element of the movable telescopic tube.

21. The rotational atherectomy device of claim 20 wherein the detent comprises a ball.

22. The rotational atherectomy device of claim 20 wherein the spring is a coil spring.

23. The rotational atherectomy device of claim 20 wherein the spring is a leaf spring.

24. The rotational atherectomy device of claim 23 wherein the leaf spring is formed integrally as a portion of the prime mover carriage.

25. The rotational atherectomy device of claim 20 further including a longitudinal spring positioned longitudinally between the detent and the prime mover carriage for moving the prime mover carriage and the shank proximally with respect to the movable telescopic tube after the detent has engaged the complementary groove and after the pressure moving the prime mover carriage distally with respect to the longitudinally extendable tube has been released.

26. The rotational atherectomy device of claim 1 further comprising a tube attachment mechanism positioned to removably attach the longitudinally extendable tube to the prime mover carriage, the tube attachment mechanism including complementary camming surfaces defined by elements of the prime mover carriage and the longitudinally extendable tube, at least one of the camming surfaces being carried by a radially resilient member, the camming surfaces being oriented so that, when distal pressure moves the prime mover carriage distally to its most distal position with respect to the longitudinally extendable tube the distal pressure causes the camming surfaces to slide with respect to each other, thereby forcing the radially resilient member to deflect radially outwardly.

27. The rotational atherectomy device of claim 26 wherein the radially resilient member is carried by the prime mover carriage.

28. The rotational atherectomy device of claim 27 wherein the radially resilient member is comprised of a distally extending resilient finger having a detent which defines the camming surface defined by said element of the prime mover carriage.

29. The rotational atherectomy device of claim 26 wherein the camming surface defined by said element of the prime mover carriage is beveled distally outwardly.

30. The rotational atherectomy device of claim 26 wherein the camming surface defined by said element of the longitudinally extendable tube is beveled distally outwardly.

31. The rotational atherectomy device of claim 30 wherein the camming surface defined by said element of the longitudinally extendable tube comprises a distal portion of a radially inwardly extending groove.

32. The rotational atherectomy device of claim 26 wherein the tube attachment mechanism comprises a plurality of radially resilient members carried by the prime mover carriage, each radially resilient member including a distally extending finger having a detent which defines the camming surface associated with the prime mover carriage.

33. The rotational atherectomy device of claim 26 or 32 wherein the tube attachment mechanism includes at least three such radially resilient members.

34. The rotational atherectomy device of claim 1 further comprising a tube attachment mechanism positioned to removably attach the longitudinally extendable tube to the prime mover carriage, the tube attachment mechanism including complementary camming surfaces defined by elements of the prime mover carriage and the longitudinally extendable tube, at least one of the camming surfaces being carried by a radially resilient member, the camming surfaces being oriented so that, after the prime mover carriage has been advanced to its most distal position with respect to the longitudinally extendable tube and pressure moving the prime mover carriage distally with respect to the tube has been released, the radially resilient member attempts to regain its non-deflected configuration, causing the camming surfaces to slide and longitudinally move with respect to each other, thereby moving the prime mover carriage and the drive shaft shank proximally with respect to the longitudinally extendable tube.

35. The rotational atherectomy device of claim 1 further comprising a tube attachment mechanism positioned to removably attach the longitudinally extendable tube to the prime mover carriage, the tube attachment mechanism including one or more radially resilient members carried by the prime mover carriage, the radially resilient member(s) being sized and positioned to removably attach the longitudinally extendable tube to the prime mover carriage.

36. The rotational atherectomy device of claim 35 wherein each radially resilient member comprises a distally extending finger having a detent receivable in a complementary groove formed in an element of the longitudinally extendable tube.

37. The rotational atherectomy device of claim 1 further comprising a tube attachment mechanism positioned to removably attach the longitudinally extendable tube to the prime mover carriage, the tube attachment mechanism including complementary proximal camming surfaces defined by elements of the prime mover carriage and the longitudinally extendable tube, at least one of the proximal camming surfaces being carried by a radially resilient member, the proximal camming surfaces being oriented with respect to each other so that, when the prime mover carriage is attached to the longitudinally extendable tube, relative movement of the cartridge housing and the prime mover carriage away from each other will cause the proximal camming surfaces to slide and move longitudinally with respect to each other so that the proximal camming surfaces become disengaged from each other, thereby permitting the prime mover carriage to be detached from the longitudinally extendable tube.

38. The rotational atherectomy device of claim 1 wherein the elongated shank has a longitudinal axis and includes distal and proximal portions, the proximal portion of the elongated shank having at least one flat surface which is substantially parallel to the longitudinal axis of the shank.

39. The rotational atherectomy device of claim 38 wherein the proximal portion of the shank has two or more flat surfaces which are substantially parallel to the longitudinal axis of the shank.

40. The rotational atherectomy device of claim 38 wherein the outer periphery of the proximal portion of the elongated shank is comprised of two or more flat surfaces and two or more generally cylindrical surfaces.

41. The rotational atherectomy device of claim 38 wherein the proximal portion of the shank has four or more flat surfaces which are substantially parallel to the longitudinal axis of the shank.

42. The rotational atherectomy device of claim 38 wherein the outer periphery of the proximal portion of the elongated shank is comprised of four or more flat surfaces and four or more generally cylindrical surfaces.

43. The rotational atherectomy device of claim 38 wherein the proximal portion of the elongated shank has a generally frusto-conical proximal end.

44. The rotational atherectomy device of claim 38 wherein the distal portion of the elongated shank includes a radially outwardly extending flange.

45. The rotational atherectomy device of claim 1 wherein at least a portion of the shank'"'"'s outer periphery is non-circular in transverse cross-section.

46. The rotational atherectomy device of claim 1 wherein the shank has a central lumen in which the drive shaft may be secured.

47. The rotational atherectomy device of claim 46 further comprising a length of flexible tubing disposed about at least a part of the proximal portion of the drive shaft.

48. The rotational atherectomy device of claim 47 wherein the central lumen of the shank has distal and proximal portions, the diameter of the distal portion of the shank being larger than the diameter of the proximal portion of the shank, a part of the length of the flexible tubing being disposed within the distal portion of the shank'"'"'s lumen.

49. The rotational atherectomy device of claim 1 wherein the prime mover carriage is movable distally from a range of working positions to a carriage-restrained position, the carriage-restrained position of the prime mover carriage being positioned within the handle housing so that, when the cartridge housing is attached to the handle housing, advancement of the prime mover carriage to its carriage-restrained position assures sufficient distal movement of the prime mover carriage with respect to the shank and the longitudinally extendable tube so that the shank of the drive shaft is inserted into the prime mover socket and the movable telescopic tube is attached to the prime mover carriage.

50. The rotational atherectomy device of claim 49 further comprising a carriage restraining mechanism carried by the handle housing for inhibiting advancement of the prime mover carriage from the range of working positions to the carriage-restrained position.

51. The rotational atherectomy device of claim 50 wherein the carriage restraining mechanism comprises a disengageable mechanical linkage between the prime mover carriage and the handle housing.

52. The rotational atherectomy device of claim 51 wherein the disengageable mechanical linkage comprises a detent and a complementary member engageable with the detent.

53. The rotational atherectomy device of claim 52 wherein the handle housing includes an elongated slot defined by opposing walls of the handle housing and the carriage includes a shaft extending radially outwardly between the opposing walls of the elongated slot in the handle housing.

54. The rotational atherectomy device of claim 53 wherein the detent is comprised of a narrowed portion in the elongated slot of the handle housing.

55. The rotational atherectomy device of claim 54 wherein the shaft extending outwardly from the carriage has a diameter larger than the width of the narrowed portion in the elongated slot of the handle housing.

56. The rotational atherectomy device of claim 54 wherein the shaft extending outwardly from the carriage includes a collar disposed about the shaft, the collar having a diameter that is larger than the width of the narrowed portion in the elongated slot of the handle housing.

57. The rotational atherectomy device of claim 55 or 56 wherein the narrowed portion of the elongated slot is constructed so that when the shaft is urged into the narrowed portion of the elongated slot the narrowed portion resiliently widens to permit the shaft to pass therethrough.

58. The rotational atherectomy device of claim 53 wherein the handle housing includes a relief slot extending distally from a distal end of the elongated slot.

59. The rotational atherectomy device of claim 1 further comprising a one stage interlock mechanism for removably attaching the cartridge housing to the handle housing.

60. The rotational atherectomy device of claim 59 wherein both the cartridge housing and the handle housing are comprised of generally cylindrical tubes, at least part of one of the cylindrical tubes being telescopically receivable within the other cylindrical tube.

61. The rotational atherectomy device of claim 59 wherein the interlock mechanism comprises an annular radially inwardly extending shoulder carried by the cartridge housing, the shoulder being interlockable with a complementary interlocking member comprised of a radially outwardly extending tab carried by the handle housing.

62. The rotational atherectomy device of claim 61 wherein the complementary interlocking member carried by the handle housing is comprised of a pair of circumferentially opposed, radially outwardly extending tabs.

63. The rotational atherectomy device of claim 62 wherein the interlock mechanism is releasable by compressing the annular shoulder of the cartridge housing to an oval shape and moving the shoulder distally over the tabs of the handle housing.

64. The rotational atherectomy device of claim 1 further comprising a two stage interlock mechanism for removably attaching the cartridge housing to the handle housing.

65. The rotational atherectomy device of claim 64 wherein the two stage interlock mechanism includes proximal and distal stages.

66. The rotational atherectomy device of claim 65 wherein the two stage interlock mechanism comprises a primary interlocking member carried by one of the cartridge housing and the handle housing and two complementary interlocking members carried by the other of the cartridge housing and the handle housing, the two complementary interlocking members being longitudinally spaced away from each other so that the primary interlocking member may be selectively interlocked with either one of the complementary interlocking members.

67. The rotational atherectomy device of claim 66 wherein the primary interlocking member is carried by the cartridge housing and the two complementary interlocking members are carried by the handle housing.

68. The rotational atherectomy device of claim 67 wherein the two complementary interlocking members are comprised of proximal and distal complementary interlocking members, the proximal complementary interlocking member forming a part of the proximal stage of the two stage interlock mechanism and a distal complementary interlocking member forming a part of the distal stage of the two stage interlock mechanism.

69. The rotational atherectomy device of claim 68 wherein the longitudinal distance between the proximal and distal complementary interlocking members is sufficiently long so that when, in the process of detaching the cartridge housing from the handle housing, the primary interlocking member interlocks with the distal complementary interlocking member, movement of the prime mover carriage to its proximal limit of movement assures that the drive shaft shank will be withdrawn from the prime mover socket and the longitudinally extendable tube will be detached from the prime mover carriage.

70. The rotational atherectomy device of claim 69 wherein the cartridge housing includes inner and outer tubes, the inner tube being generally coaxial with the outer tube and being telescopically receivable within the handle housing.

71. The rotational atherectomy device of claim 70 wherein the outer tube of the cartridge housing carries the primary interlocking member.

72. The rotational atherectomy device of claim 70 wherein the outer tube of the cartridge housing is shorter than the inner tube.

73. The rotational atherectomy device of claim 71 wherein the primary interlocking member is comprised of an annular radially inwardly extending shoulder.

74. The rotational atherectomy device of claim 73 wherein the annular shoulder has an inner diameter which is sufficiently larger than an outer diameter of the inner tube so that the annular shoulder may be compressed to an oval shape.

75. The rotational atherectomy device of claim 74 wherein the proximal complementary interlocking member is comprised of a radially outwardly extending tab carried by the handle housing so that the proximal stage of the two stage interlock mechanism is releasable by compressing the annular shoulder of the cartridge housing to an oval shape and moving the shoulder distally over the tab.

76. The rotational atherectomy device of claim 75 wherein the distal complementary interlocking member is comprised of a radially outwardly extending tab carried by the handle housing so that each stage of the two stage interlock mechanism is releasable by compressing the annular shoulder of the cartridge housing to the oval shape and moving the shoulder distally over the tab.

77. The rotational atherectomy device of claim 75 wherein the distal interlocking member is comprised of a pair of radially outwardly extending tabs carried by the handle housing, the tabs being longitudinally spaced away from each other to define a groove having a longitudinal width which is sufficient to receive the annular shoulder of the cartridge housing so that when, in the process of detaching the cartridge housing from the handle housing, the annular shoulder of the cartridge housing is received in the groove, it becomes captured between the proximal and distal tabs defining the groove.

78. The rotational atherectomy device of claim 74 wherein the proximal complementary interlocking member is comprised of a pair of circumferentially opposed, radially outwardly extending tabs carried by the handle housing so that the proximal stage of the two stage interlock mechanism is releasable by compressing the annular shoulder of the cartridge housing to an oval shape and moving the shoulder distally over the tabs.

79. The rotational atherectomy device of claim 78 wherein a wall of the handle housing includes a pair of proximal windows located circumferentially opposite each other and between the tabs comprising the proximal interlocking member, the windows permitting the annular shoulder of the cartridge housing to be compressed to an oval shape.

80. The rotational atherectomy device of claim 78 wherein the distal complementary interlocking member is comprised of a pair of circumferentially opposed, radially outwardly extending tabs carried by the handle housing so that each stage of the two stage interlock mechanism is releasable by compressing the annular shoulder of the cartridge housing to the oval shape and moving the shoulder distally over the tabs.

81. The rotational atherectomy device of claim 80 wherein the distal interlocking member is comprised of a pair of radially outwardly extending tabs carried by the handle housing, the tabs being longitudinally spaced away from each other to define a groove having a longitudinal width which is sufficient to receive the annular shoulder of the cartridge housing therein so that when, in the process of detaching the cartridge housing from the handle housing, the annular shoulder of the cartridge housing is received in the groove, it becomes captured between the proximal and distal tabs defining the groove.

82. The rotational atherectomy device of claim 81 wherein the distal complementary interlocking member is comprised of two pairs of radially outwardly extending tabs carried by the handle housing, each pair of tabs defining a groove having a longitudinal width which is sufficient to receive the annular shoulder of the cartridge housing.

83. The rotational atherectomy device of claim 82 wherein the two grooves defined by the tabs are longitudinally aligned with each other and circumferentially opposed to each other so that when, in the process of detaching the cartridge housing from the handle housing, the annular shoulder of the cartridge housing is received in the grooves, it becomes captured between the proximal and distal tabs defining the grooves.

84. The rotational atherectomy device of claim 80 or 82 wherein a wall of the handle housing includes a pair of distal windows located circumferentially opposite each other and between the tabs comprising the distal interlocking member, the windows permitting the annular shoulder of the cartridge housing to be compressed to an oval shape.

85. The rotational atherectomy device of claim 80 or 82 wherein the wall of the handle housing includes a pair of distally open recesses located circumferentially opposite each other and between the tabs comprising the distal interlocking member, the recesses permitting the annular shoulder of the cartridge housing to be compressed to an oval shape.

86. The rotational atherectomy device of claim 80 or 82 wherein the tabs of the proximal complementary interlocking member and the tabs of the distal complementary interlocking member not only are spaced longitudinally from each other but are also circumferentially positioned at about a 90 degree angle with respect to each other so that, in the process of detaching the cartridge housing from the handle housing, the annular shoulder of the cartridge housing has to be compressed to the oval shape at least two times, the first time to be moved distally over the tabs comprising the proximal complementary interlocking member, and the second time to be moved distally over the tabs comprising the distal complementary interlocking member.

87. The rotational atherectomy device of claim 66 wherein the primary interlocking member is comprised of a radially inwardly extending tab carried by the handle housing, and each of the two complementary interlocking members is comprised of an annular radially inwardly extending groove formed in an outer surface of the cartridge housing, each of the grooves having a longitudinal width sufficient to interlock with the radially inwardly extending tab.

88. The rotational atherectomy device of claim 87 wherein the two complementary interlocking members are comprised of proximal and distal complementary interlocking members, the proximal complementary interlocking member forming a part of the proximal stage of the two stage interlock mechanism and the distal complementary interlocking member forming a part of the distal stage of the two stage interlock mechanism.

89. The rotational atherectomy device of claim 88 wherein the longitudinal distance between the proximal and distal complementary interlocking members is sufficiently long so that when, in the process of detaching the exchangeable cartridge from the handle housing, the primary interlocking member interlocks with the proximal complementary interlocking member, movement of the prime mover carriage to its proximal limit of movement assures that the drive shaft shank will be withdrawn from the prime mover socket and the longitudinally extendable tube will be detached from the prime mover carriage.

90. The rotational atherectomy device of claim 89 wherein both the cartridge housing and the handle housing are comprised of generally cylindrical tubes, at least part of the cartridge housing being telescopically receivable within the handle housing.

91. The rotational atherectomy device of claim 90 wherein the radially inwardly extending tab is carried by an annular collar secured to the handle housing, at least a portion of the collar extending distally from the handle housing.

92. The rotational atherectomy device of claim 91 wherein the annular collar carrying the tab has an inner diameter which is sufficiently larger than an outer diameter of the cartridge housing to permit the annular collar to be compressed to an oval shape to disengage the tab from the groove.

93. The rotational atherectomy device of claim 92 wherein the primary interlocking member is comprised of a pair of circumferentially opposed, radially inwardly extending tabs, each stage of the two stage interlock mechanism being releasable by compressing the annular collar to an oval shape so that the tabs become disengaged from the groove in the cartridge housing and the cartridge housing can be moved distally with respect to the handle housing.

94. The rotational atherectomy device of claim 66 wherein the primary interlocking member is comprised of a radially inwardly extending tab carried by the cartridge housing, and each of the two complementary interlocking members is comprised of an annular radially inwardly extending groove in a wall of the handle housing, each of the grooves having a longitudinal width sufficient to interlock with the radially inwardly extending tab.

95. The rotational atherectomy device of claim 94 wherein the two complementary interlocking members are comprised of proximal and distal complementary interlocking members, the proximal complementary interlocking member forming a part of the proximal stage of the two stage interlock mechanism and the distal complementary interlocking member forming a part of the distal stage of the two stage interlock mechanism.

96. The rotational atherectomy device of claim 95 wherein the longitudinal distance between the proximal and distal complementary interlocking members is sufficiently long so that when, in the process of detaching the exchangeable cartridge from the handle housing, the primary interlocking member interlocks with the distal complementary interlocking member, movement of the prime mover carriage to its proximal limit of movement assures that the drive shaft shank will be withdrawn from the prime mover socket and the longitudinally extendable tube will be detached from the prime mover carriage.

97. The rotational atherectomy device of claim 96 wherein both the handle housing and the cartridge housing are comprised of generally cylindrical tubes, at least part of the handle housing being telescopically receivable within the cartridge housing.

98. The rotational atherectomy device of claim 97 wherein the radially inwardly extending tab is carried by an annular collar secured to the cartridge housing, at least a portion of the collar extending proximally from the cartridge housing.

99. The rotational atherectomy device of claim 98 wherein the annular collar carrying the tab has an inner diameter which is sufficiently larger than an outer diameter of the handle housing to permit the annular collar to be compressed to an oval shape to disengage the tab from the groove.

100. The rotational atherectomy device of claim 99 wherein the primary interlocking member is comprised of a pair of circumferentially opposed, radially inwardly extending tabs, each stage of the two stage interlock mechanism being releasable by compressing the annular collar to an oval shape so that the tabs become disengaged from the groove and the cartridge housing can be moved distally with respect to the handle housing.

101. The rotational atherectomy device of claim 1 further comprising a flexible fluid supply tube attached to the exchangeable drive shaft cartridge and in fluid communication with a drive shaft lumen of the drive shaft cartridge, the drive shaft lumen being defined by a lumen of the catheter and a lumen of the longitudinally extendable tube.

102. The rotational atherectomy device of claim 101 wherein the drive shaft lumen receives a majority of the length of the drive shaft.

103. The rotational atherectomy device of claim 101 wherein a flexible thin-walled tube extends along a length of the drive shaft from a distal end of the drive shaft shank to a point located distally of a distal end of the longitudinally extendable tube.

104. The rotational atherectomy device of claim 103 wherein the flexible thin-walled tube extends distally beyond the location where the fluid supply tube delivers fluid to the drive shaft lumen.

105. The rotational atherectomy device of claim 103 wherein the flexible thin-walled tube extends distally into the proximal end portion of the catheter.

106. The rotational atherectomy device of claim 103 wherein the flexible thin-walled tube is a heat-shrinkable tube.

107. The rotational atherectomy device of claim 103 wherein the flexible thin-walled tube is a heat-shrinkable polyester tube.

108. The rotational atherectomy device of claim 101 wherein the fluid supply tube delivers fluid from a fluid supply external to the exchangeable drive shaft cartridge.

109. The rotational atherectomy device of claim 101 wherein the fluid supply tube is attached to the exchangeable drive shaft cartridge distally of the drive shaft shank.

110. The rotational atherectomy device of claim 101 wherein the fluid supply tube is attached to the exchangeable drive shaft cartridge distally of the drive shaft shank and proximally of the catheter.

111. The rotational atherectomy device of claim 101 wherein the fluid supply tube is attached to the exchangeable drive shaft cartridge distally of the prime mover carriage.

112. The rotational atherectomy device of claim 101 wherein the fluid supply tube is attached to the exchangeable drive shaft cartridge distally of the prime mover carriage and proximally of the catheter.

113. The rotational atherectomy device of claim 101 wherein the fluid supply tube is attached to the exchangeable drive shaft cartridge distally of the longitudinally extendable tube and proximally of the catheter.

114. The rotational atherectomy device of claim 101 wherein the fluid supply tube is attached to the exchangeable drive shaft cartridge adjacent a distal end of the longitudinally extendable tube.

115. The rotational atherectomy device of claim 101 wherein the fluid supply tube is attached to the cartridge housing adjacent to a distal end of the cartridge housing.

116. The rotational atherectomy device of claim 101 wherein the fluid supply tube is attached to a distal end piece of the cartridge housing.

117. The rotational atherectomy device of claim 101 wherein the longitudinally extendable tube includes at least two telescopic tubes.

118. The rotational atherectomy device of claim 117 wherein the fluid supply tube is attached to the exchangeable drive shaft cartridge distally of at least one of the telescopic tubes.

119. The rotational atherectomy device of claim 117 wherein the fluid supply tube is attached to the exchangeable drive shaft cartridge distally of all of the telescopic tubes.

120. The rotational atherectomy device of claim 117 wherein the fluid supply tube is attached to the exchangeable drive shaft cartridge distally of at least one of the telescopic tubes and proximally of the catheter.

121. The rotational atherectomy device of claim 117 wherein the fluid supply tube is attached to the cartridge housing proximally of the catheter.

122. The rotational atherectomy device of claim 1 wherein the prime mover carriage includes a tapered inlet for guiding the longitudinally extendable tube inside the prime mover carriage when the prime mover carriage is moved distally to be attached to the longitudinally extendable tube.

123. A rotational atherectomy device comprising:

a handle housing;

an exchangeable drive shaft cartridge including

a cartridge housing which is removably attachable to the handle housing;

an elongated catheter having a proximal end portion which is carried by the cartridge housing; and

a rotatable flexible drive shaft substantially disposed within the catheter,

the drive shaft having a tissue removal implement disposed near its distal end;

a two stage interlock mechanism removably attaching the cartridge housing to the handle housing;

a rotatable prime mover carried by a prime mover carriage which is disposed within the handle housing, the prime mover carriage being longitudinally movable with respect to the handle housing; and

a drive shaft attachment mechanism removably attaching the drive shaft to the prime mover;

whereby the cartridge housing may be attached to and detached from the handle housing and the drive shaft may be attached to and detached from the prime mover, thereby permitting the exchangeable drive shaft cartridge to be selectively attached to and detached from the handle housing.

124. A rotational atherectomy device comprising:

a handle housing;

a rotatable prime mover carried by a prime mover carriage which is disposed within the handle housing, the prime mover carriage being longitudinally movable with respect to the handle housing;

an exchangeable drive shaft cartridge having

a cartridge housing which is removably attachable to the handle housing;

a longitudinally extendable tube having a distal end portion carried by the cartridge housing and a proximal end portion which is removably attachable to the prime mover carriage for longitudinal movement therewith;

an elongated catheter having a proximal end portion which is carried by the cartridge housing; and

a rotatable flexible drive shaft having proximal, intermediate and distal portions, the intermediate portion being disposed primarily within the longitudinally extendable tube and the catheter, and the distal portion extending distally from the catheter and having a tissue removal implement; and

a drive shaft attachment mechanism removably attaching the proximal portion of the drive shaft to the prime mover.

125. A method of attaching an exchangeable drive shaft cartridge, having a tissue removal implement, to a handle housing portion of a rotational atherectomy device, comprising the steps of:

providing a handle housing having a rotatable prime mover carried by a prime mover carriage, the prime mover carriage being longitudinally movable with respect to the handle housing and having a distally facing prime mover socket;

providing an exchangeable drive shaft cartridge including

a cartridge housing which is removably attachable to the handle housing;

a longitudinally extendable tube having a distal end portion carried by the cartridge housing and a proximal end portion which is removably attachable to the prime mover carriage for longitudinal movement therewith; and

a rotatable flexible drive shaft having proximal and distal portions, the proximal portion being attached to an elongated shank removably attachable to the prime mover socket, the distal portion of the flexible drive shaft having a tissue removal implement;

attaching the cartridge housing to the handle housing by moving the cartridge housing proximally with respect to the handle housing; and

connecting the longitudinally extendable tube to the prime mover carriage and inserting the shank into the prime mover socket by moving the prime mover carriage distally with respect to the longitudinally extendable tube and the shank.

126. A method of detaching an exchangeable drive shaft cartridge, having a tissue removal implement, from a rotational atherectomy device, comprising the steps of:

providing a handle housing having a rotatable prime mover carried by a prime mover carriage, the prime mover carriage being longitudinally movable with respect to the handle housing and having a distally facing prime mover socket;

providing an exchangeable drive shaft cartridge including

a cartridge housing which is removably attachable to the handle housing;

a longitudinally extendable tube having a distal end portion carried by the cartridge housing and a proximal end portion which is removably attachable to the prime mover carriage for longitudinal movement therewith; and

a rotatable flexible drive shaft having proximal and distal portions, the proximal portion being attached to an elongated shank removably attachable to the prime mover socket, the distal portion of the flexible drive shaft having a tissue removal implement;

at least partially detaching the cartridge housing from the handle housing by moving the cartridge housing distally with respect to the handle housing; and

disconnecting the longitudinally extendable tube from the prime mover carriage and detaching the shank from the prime mover socket by moving the prime mover carriage proximally with respect to the longitudinally extendable tube and the shank.

127. A method of detaching one exchangeable drive shaft cartridge, having a tissue removal implement, from a rotational atherectomy device and replacing it with another exchangeable drive shaft cartridge, having another tissue removal implement, comprising the steps of:

providing a handle housing having a rotatable prime mover carried by a prime mover carriage, the prime mover carriage being longitudinally movable with respect to the handle housing and having a distally facing prime mover socket;

providing a first exchangeable drive shaft cartridge including

a cartridge housing which is removably attachable to the handle housing;

a longitudinally extendable tube having a distal end portion carried by the cartridge housing and a proximal end portion which is removably attachable to the prime mover carriage for longitudinal movement therewith; and

a rotatable flexible drive shaft having proximal and distal portions, the proximal portion being attached to an elongated shank removably attachable to the prime mover socket, the distal portion of the flexible drive shaft having a tissue removal implement;

at least partially detaching the cartridge housing from the handle housing by moving the cartridge housing distally with respect to the handle housing; and

disconnecting the longitudinally extendable tube from the prime mover carriage and detaching the shank from the prime mover socket by moving the prime mover carriage proximally with respect to the longitudinally extendable tube and the shank;

providing a second exchangeable drive shaft cartridge including

a second cartridge housing which is removably attachable to the handle housing;

a second longitudinally extendable tube having a distal end portion carried by the second cartridge housing and a proximal end portion which is removably attachable to the prime mover carriage for longitudinal movement therewith; and

a second rotatable flexible drive shaft having proximal and distal portions, the proximal portion being attached to a second elongated shank removably attachable to the prime mover socket, the distal portion of the second flexible drive shaft having a second tissue removal implement;

attaching the second cartridge housing to the handle housing by moving the cartridge housing proximally with respect to the handle housing; and

connecting the second longitudinally extendable tube to the prime mover carriage and inserting the second shank into the prime mover socket by moving the prime mover carriage distally with respect to the second longitudinally extendable tube and the second shank.