Catheter with electrosurgical cutter

• US 5,904,679 A
• Filed: 03/22/1994
• Issued: 05/18/1999
• Est. Priority Date: 01/18/1989
• Status: Expired due to Term

• Current Assignee: Applied Medical Resources Corporation (Applied Medical Corporation)
• Original Assignee: Applied Medical Resources Corporation (Applied Medical Corporation)
• Inventors: Clayman, Ralph V.
• Primary Examiner(s): STRIGHT, RONALD K
• Application Number:
  US08/216,512
• Time in Patent Office: 1,883 Days
• Field of Search: 606/7, 606/28, 606/37, 606/39, 606/45, 606/49, 606/159, 606/113, 606/194, 128/757, 128/751, 604/20, 604/22, 604/114, 600/370, 600/564, 607/99, 607/101, 607/113
• US Class Current: 606/39
• CPC Class Codes: A61B 17/22 Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for dilators A61M29/00
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 18/08 by means of electrically-heated probes
• CPC Class Codes: A61B 18/082 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2017/00292 mounted on or guided by flexible, e.g. catheter-like, means
• CPC Class Codes: A61B 2017/22061 for spreading elements apart
• CPC Class Codes: A61B 2017/22062 to be filled with liquid
• CPC Class Codes: A61B 2018/00107 Coatings on the energy applicator
• CPC Class Codes: A61B 2018/00148 with metal
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/0022 Balloons
• CPC Class Codes: A61B 2018/00285 Balloons
• CPC Class Codes: A61B 2018/00386 Coronary vessels
• CPC Class Codes: A61B 2018/00422 Angioplasty
• CPC Class Codes: A61B 2018/1213 creating an arc
• CPC Class Codes: A61B 2018/1253 monopolar
• CPC Class Codes: A61B 2018/1407 Loop
• CPC Class Codes: A61B 2018/144 : Wire
• CPC Class Codes: A61B 2018/1475 : Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61M 2025/1093 : having particular tip characteristics
• CPC Class Codes: A61M 2205/32 : with radio-opaque indicia
• CPC Class Codes: A61M 25/09 : Guide wires
• CPC Class Codes: A61M 25/104 : used for angioplasty
• CPC Class Codes: A61M 29/02 : Dilators made of swellable material balloon catheters for angioplasty A61M25/104
• CPC Class Codes: A61M 3/0279 : Cannula; Nozzles; Tips; their connection means

Abstract

A catheter assembly which permits simultaneous dilatation and incision of tissue whereby trauma and damage to the tissue due to uncontrolled tearing is reduced or eliminated comprising an elongated tubular body having a distal end that carries a dilatation balloon and cutting element carried on the exterior of the balloon and that moves radially in concert with the exterior of the bladder as the bladder is inflated and deflated. A radiofrequency current is directed through the cutting element to incise proximate tissue. Pressure can be applied to the tissue prior to cutting to facilitate separation and subsequent to cutting to inhibit bleeding.

Claims

1. A method for dilating a non-vascular body conduit, comprising:

inserting into the non-vascular conduit a dilation catheter assembly comprising an elongate tubular body having a distal end carrying a radially dilatable member adapted to be positioned in the conduit and to exert pressure on surrounding body tissue to provide a substantially uniform tangential tension in the tissue, and a cutting element carried on the dilatable member;

dilating the dilatable member to simultaneously stress the tissue and engage the tissue with the cutting element;

electrically activating the cutting element;

incising the stressed tissue with the cutting element;

radially contracting the dilatable member to cause the dilatable member and cutting element to disengage the tissue; and

withdrawing the dilation catheter assembly from the conduit.

2. The method of claim 1 wherein the cutting element is a radiofrequency cutter and the method further including the steps of:

passing a radiofrequency current through the cutter during the dilating of the dilatable member; and

,

discontinuing the radiofrequency current during the radial contracting of the dilatable member.

3. The method of claim 2 wherein the step of passing the radiofrequency current includes the steps of:

introducing a radiofrequency signal into the cutting element to cut the tissue; and

reducing the power of the radiofrequency signal to cauterize the cut tissue.

4. The method of claim 1 including the step of cauterizing the tissue with the cutting element.

5. A method for enlarging the diameter of a ureteral passage defined by body tissue, comprising:

inserting into the ureteral passage a catheter having a catheter body, a cutting element in the form of an elongate wire, and means for advancing the cutting element laterally of the catheter body;

advancing the cutting element into proximity with the tissue; and

electrically activating the cutting element to cut the tissue and enlarge the diameter of the ureteral passage.

6. The method recited in claim 5 wherein after the activating step, the method further comprises the steps of stretching the tissue defining the ureteral passage in order to enlarge the ureteral passage.

7. The method recited in claim 6 further comprising the step of pressurizing the cut tissue to inhibit bleeding of the tissue.

8. The method recited in claim 7 further comprising the steps of:

deactivating the cutting element;

retracting the cutting element into proximity to the catheter body; and

withdrawing the catheter from the ureteral passage.

9. The method recited in claim 7 wherein during the providing step, the catheter is provided with an inflatable balloon and during at least one of the advancing, stretching, and pressurizing steps, the method further comprises the step of inflating the balloon.

10. The method recited in claim 5 wherein after the activating step, the method further comprises the step of advancing the cutting element into proximity with previously uncut tissue.

11. The method recited in claim 5 wherein during the activating step the tissue is cut into two portions and the method further comprises the step of separating the two cut portions of the tissue to expose uncut tissue to the cutting element.

12. The method recited in claim 5 wherein prior to the activation step the method further comprises the step of stretching the tissue in proximity to the cutting element.

13. A method for enlarging the diameter of a passage defined by body tissue and having a longitudinal axis, comprising:

inserting into the passage a catheter having an inflatable balloon and a cutting element in the form of an electrosurgical wire disposed in contact with the outer surface of the balloon;

inflating the balloon to move the cutting element into proximity with the body tissue;

activating electrically the cutting element to cut the body tissue in only a substantially axial direction;

deflating the balloon to withdraw the cutting element from proximity with the body tissue; and

withdrawing the catheter from the passage.

14. The method recited in claim 13 wherein prior to the deflating step the method further comprises the step of advancing the cutting element into proximity with previously uncut tissue.

15. The method recited in claim 14 further comprising the step of repeating the activating step.

16. The method recited in claim 13 wherein prior to the activating step the method further comprises the step of stretching the body tissue.

17. The method recited in claim 13 wherein subsequent to the activating step the method further comprises the step of pressurizing the cut tissue to inhibit bleeding.

18. The method recited in claim 13 wherein prior to the deflating step the method further comprises the step of deactivating the cutting element to discontinue cutting the body tissue.

19. The method recited in claim 13 wherein during the deflating step the method further comprises the step of automatically retracting the cutting element from proximity with the body tissue.

20. A method for enlarging the diameter of a passage defined by body tissue, comprising:

inserting into the passage a catheter having a wall defining a lumen extending between a distal end of the catheter and a proximal end of the catheter, and an electrosurgical wire having first portions disposed exteriorly of the catheter and second portions disposed interiorly of the catheter, the wire including a first end fixed to the catheter and a second end movable within the lumen of the catheter to vary the length of the first portions of the wire relative to the length of the second portions of the wire;

moving the second end of the wire distally within the lumen of the catheter to increase the length of the first portions of the wire and thereby move the first portions laterally of the catheter wall into proximity with the tissue;

activating the electrosurgical wire to cut the tissue in proximity to the wire; and

moving the second end of the wire proximally within the lumen of the catheter to decrease the length of the first portions of the wire and thereby move the first portions laterally of the catheter wall into proximity with the catheter wall.

21. The method recited in claim 20 further comprising the step of providing the catheter with a balloon disposed between the wire and the catheter wall, the balloon being inflatable to move the wire into proximity with the body tissue.

22. The method recited in claim 21 wherein the first moving step includes the step of inflating the balloon through the lumen of the catheter wall.

23. The method recited in claim 22 wherein the second moving step includes the step of deflating the balloon through the lumen of the catheter wall.

24. The method recited in claim 21 further comprising the step of attaching the first end of the wire to the catheter distally of the balloon.

25. The method recited in claim 21 further comprising the step of attaching the first end of the wire to the catheter wall proximally of the balloon.

26. A catheter assembly adapted for use in the urinary system and comprising in combination:

an elongate tubular body having a lumen and an axis extending to a distal end;

a dilatable member having an outwardly facing exterior surface and being disposed to surround the distal end of the tubular body in communication with the lumen of the tubular body, the dilatable member being adapted for disposition in the urinary system and being dilatable in response to fluid pressure in the lumen of the tubular body to exert pressure on surrounding body tissue in order to create tension in the body tissue;

cutting means disposed substantially only axially to extend in close contacting relationship with the exterior surface of the dilatable member and having characteristics for being moved into proximity with the surrounding tissue when the dilatable member is dilated, for incising said tissue axially along the tubular body to relieve the tension in the body tissue and to enlarge the body conduit; and

means for electrically energizing the cutting means to permit incision and cauterization of the tissue.

27. The assembly of claim 26 wherein the dilatable member is an inflatable bladder that is adapted to be inflated to a predetermined volume and shape.

28. The assembly of claim 27 wherein the cutting means is permanently affixed to the inflatable bladder.

29. The catheter assembly recited in claim 27 wherein the inflatable bladder is symmetrically disposed around the tubular body and the dilation of the inflatable bladder exerts an uniform tangential tension on the surrounding tissue.

30. The assembly of claim 26 wherein the cutting means is an integral component of the dilatable member.

31. The assembly of claim 26 wherein the cutting means comprises a thin wire.

32. The assembly of claim 26 including an open ended sheath from which the tubular body may be ejected for use and into which the tubular body may be retracted after use.

33. The catheter assembly recited in claim 26 wherein the cutting means comprises a radiofrequency electrosurgical cutting element.

34. A catheter adapted to cut tissue, comprising:

a tube having a longitudinal axis extending between a distal end and a proximal end of the catheter;

cutting means disposed generally at the distal end of the tube for cutting the tissue, the cutting means including only a single axially oriented wire, having no point of intersection with any second cutting wire, the single wire having portions movable radially of the axis of the catheter;

means for moving the cutting means portions radially into close proximity to the tissue to be cut;

means for electrically activating the cutting means to cut the tissue in proximity to the cutting means; and

means for exposing previously uncut tissue to the cutting means.

35. The catheter recited in claim 34 wherein the moving means comprises a balloon inflatable through the tube and having portions disposed in a fixed relationship with the tube of the catheter.

36. The catheter recited in claim 35 wherein the balloon has a longitudinal axis generally aligned with the longitudinal axis of the tube.

37. The catheter recited in claim 35 wherein the balloon has an outer surface and the wire is movable radially with the outer surface when the balloon is inflated.

38. The catheter recited in claim 34 wherein the exposing means includes means operable with the tube stationary relative to the tissue for applying a force to the tissue to separate the cut tissue and thereby move the uncut tissue into proximity with the cutting means.

39. The catheter recited in claim 38 wherein the exposing means includes a balloon inflatable through the tube and having a curved outer surface, and the force is applied to the tissue tangentially of the outer surface of the balloon.

40. The catheter recited in claim 34 further comprising tamponade means for applying pressure to the cut tissue.

41. The catheter recited in claim 34 wherein the activating means comprises means for directing an electrosurgical signal through the wire, the signal having a magnitude sufficient to cut the tissue.

42. A catheter adapted to cut tissue, comprising:

a tube having a longitudinal axis extending between a distal end and a proximal end of the catheter;

cutting means disposed generally at the distal end of the tube for cutting the tissue, the cutting means including only a single axially oriented wire having no point of intersection with any second cutting wire, the single wire having portions movable radially of the axis of the catheter;

means for moving the cutting means portions radially into close proximity to the tissue to be cut, comprising a balloon inflatable through the tube and having portions disposed in a fixed relationship with the tube of the catheter, the balloon having an outer surface and the wire being movable radially with the outer surface when the balloon is inflated, the balloon having first and second ends fixed to the tube, and the wire having a first end fixed relative to the first end of the balloon and a second end movable relative to the second end of the balloon; and

means for activating the cutting means to cut the tissue in proximity to the cutting means; and

means for exposing previously uncut tissue to the cutting means.

43. The catheter recited in claim 42 wherein the wire has a proximal end and a distal end and the first end of the wire is the distal end of the wire.

44. Apparatus for cutting a non-vascular body conduit comprising:

a supporting structure having an outer surface;

an electrosurgical cutter in the form of a wire having first portions disposed in a fixed relationship with the supporting structure and second portions disposed outwardly of the outer surface in a movable relationship with the supporting structure;

means disposed between the supporting structure and the second portions of the cutter for moving the second portions of the cutter into proximity with the tissue to be cut; and

means for electrically activating the cutter to cut the non-vascular body conduit.

45. The apparatus recited in claim 44 wherein the supporting structure defines a lumen and the moving means comprises a balloon inflatable through the lumen and having first portions fixed to the catheter and second portions movable relative to the catheter, the second portions of the balloon being disposed between the catheter and the second portions of the cutter to move the cutter into proximity with the non-vascular body conduit when the balloon is inflated.

46. Tissue cutting apparatus, comprising:

a supporting structure including portions defining a lumen and having an outer surface;

an electrosurgical cutter in the form of a wire having first portions disposed in a fixed relationship with the supporting structure, and second portions disposed outwardly of the outer surface in a movable relationship with the supporting structure;

means disposed between the supporting structure and the second portions of the cutter for moving the second portions of the cutter into proximity with the tissue to be cut, the moving means comprising a balloon inflatable through the lumen of the supporting structure;

means for electrically activating the cutter to cut the tissue; and

means disposed between the cutter and the balloon for directing energy from the electrical cutter away from the balloon and toward the tissue.

47. The tissue cutting apparatus recited in claim 46 wherein the supporting structure is a catheter having a proximal end and a distal end, and the electrosurgical cutter is disposed near the distal end of the catheter.

48. The apparatus recited in claim 47 wherein the supporting structure defines a lumen and the moving means comprises a balloon inflatable through the lumen and having first portions fixed to the catheter and second portions movable relative to the catheter, the second portions of the balloon being disposed between the catheter and the second portions of the cutter to move the cutter into proximity with the tissue when the balloon is inflated.

49. The apparatus recited in claim 48 wherein the first portions of the balloon include first and second ends of the balloon fixed to the catheter, and the second portions of the balloon include a central region movable relative to the catheter to move the cutter outwardly from the catheter into proximity with the tissue.

50. The apparatus recited in claim 48 further comprising:

means for inflating the balloon to move the cutter into proximity with the tissue to be cut; and

means for deflating the balloon after the tissue has been cut.

51. The apparatus recited in claim 46 wherein the electrical cutter includes a wire and the directing means includes insulation disposed along the wire between the wire and the balloon.

52. The apparatus recited in claim 51 wherein the insulation forms a sleeve around the wire and portions of the sleeve are removed along the wire to direct the energy toward the tissue.

53. The apparatus recited in claim 46 wherein:

the cutter comprises a wire disposed to extend generally longitudinally of the catheter along the balloon;

the first portions of the cutter include a first end of the wire disposed in a fixed relationship with the catheter; and

,

the second portions of the cutter include a second end of the wire disposed in a movable relationship with the catheter.

54. A catheter having a longitudinal axis extending between a proximal end of the catheter and a distal end of the catheter, comprising:

a catheter body defining a lumen and a hole extending from the lumen exteriorly of the catheter;

an elongate cutting element in the form of a wire having a distal end with a fixed relationship to the catheter body, a proximal end extending through the hole into the lumen, and intermediate portions disposed between the proximal end and distal end of the wire; and

means for moving the proximal end of the wire towards the distal end of the wire for advancing the intermediate portions of the wire laterally of the axis of the catheter.

55. The catheter recited in claim 54 further comprising means for maintaining a tensile force on the cutting element.

56. The catheter recited in claim 55 wherein the maintaining means comprises a tension spring with first portions having a fixed relationship with the catheter and second portions having a fixed relationship with the second end of the cutting element.

57. The catheter recited in claim 56 wherein portions of the catheter define a lumen and the spring is disposed in the lumen of the catheter.

58. The catheter recited in claim 55 wherein operation of the advancing means provides the cutting element with different configurations each of which has the general shape of a parabola.

59. The catheter recited in claim 54 wherein the advancing means comprises a balloon with properties for being inflated and deflated, and the catheter further comprises:

means for inflating the balloon to advance the cutting element;

means for deflating the balloon; and

means for automatically retracting the cutting element in response to deflation of the balloon.

60. A catheter having a longitudinal axis extending between a proximal end of the catheter and a distal end of the catheter, comprising:

a catheter body defining a lumen and a hole extending from the lumen exteriorly of the catheter;

an elongate cutting element in the form of a wire having a proximal end with a fixed to the catheter body, a distal end extending through the hole into the lumen, and intermediate portions disposed between the proximal end and distal end of the wire; and

means for moving the distal end of the wire toward the proximal end of the wire for advancing the intermediate portions of the wire laterally of the axis of the catheter.

61. A catheter assembly comprising in combination:

an elongate tubular body having a lumen and an axis extending to a distal end;

a dilatable member having an outwardly facing exterior surface and being disposed to surround the distal end of the tubular body in communication with the lumen of the tubular body, the dilatable member being adapted for disposition in the urinary system and being dilatable in response to fluid pressure in the lumen of the tubular body to exert pressure on surrounding body tissue in order to create substantially circumferentially uniform tension in the body tissue;

cutting means comprising a wire and being disposed to extend substantially only axially along at least one half of the length of the dilatable member, and having characteristics for being moved into proximity with the surrounding tissue when the dilatable member is dilated, for incising said tissue along the tubular body to relieve the tension in the body tissue and to enlarge the body conduit.

62. The assembly of claim 61 including means for electrically energizing the cutting means to permit incision and cauterization of the tissue.

63. A catheter having a longitudinal axis extending between a proximal end of the catheter and a distal end of the catheter, comprising:

a catheter body defining a lumen and a hole extending from the lumen exteriorly of the catheter;

an elongate cutting element, at least a portion of which is always disposed exteriorly of the catheter body, said cutting element having a proximal end with a fixed relationship with the catheter body, a distal end extending through the hole into the lumen, and intermediate portions disposed between the proximal end and distal end of the cutting element; and

means for moving the distal end of the cutting element toward the proximal end of the cutting element for advancing the intermediate portions of the cutting element laterally of the axis of the catheter.

64. Tissue cutting apparatus, comprising:

a supporting structure having an outer surface;

an electrosurgical cutter in the form of a wire having first portions disposed in a fixed relationship with the supporting structure and second portions disposed outwardly of the outer surface in a movable relationship with the supporting structure, at least a portion of said second portions of the wire being disposed exteriorly of the supporting structure at all times;

means disposed between the supporting structure and the second portions of the cutter for moving the second portions of the cutter into proximity with the tissue to be cut; and

means for electrically activating the cutter to cut the tissue.