Flexible Catheter for High-Frequency Therapy of Biological Tissue and Method of Using Same

• US 20090156981A1
• Filed: 10/04/2007
• Published: 06/18/2009
• Est. Priority Date: 10/04/2006
• Status: Active Grant

• Current Assignee: Celon AG Medical Instruments
• Original Assignee: Celon AG Medical Instruments
• Inventors: Fay, Markus, Kühne, Wolfgang
• Granted Patent: US 9,750,564 B2
• Time in Patent Office: Days
• US Class Current: 604/20
• 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 2018/00345 Vascular system
• CPC Class Codes: A61B 2018/00482 Digestive system
• CPC Class Codes: A61B 2018/00559 Female reproductive organs

Abstract

A catheter for the high-frequency therapy of body lumens has a flexible shaft tube (16) of preferably biocompatible plastic material, which is connected to a distal end portion in the region of the distal end of the catheter. A proximal part (14.p) of the distal end portion (14), that projects into the distal part of the shaft tube (16), forms a clamping connection to the distal end of the shaft tube (16), which is secured by a distal electrode (18) which is drawn on to the external peripheral surface of the shaft tube, by the distal electrode exerting a radially inwardly acting clamping force on the clamping connection.

Claims

1-31. -31. (canceled)

32. A catheter for the treatment of body tissue comprising:

a flexible shaft tube of biocompatible plastic material, which defines a lumen,

at least one electrode on a distal portion of the flexible shaft tube for delivery of high-frequency alternating current to the body tissue surrounding the catheter during treatment,

at least one electric line which is electrically conductingly connected to the at least one electrode and which extends to a proximal end of the catheter, and

a distal end portion fixed to the distal end of the flexible shaft tube, a proximal end of the distal end portion projects into the lumen of the flexible shaft tube and there forms a clamping connection to the distal end of the flexible shaft tube, which is secured by a sleeve in the form of a hollow cylinder by the sleeve exerting a radially acting clamping force on the clamping connection.

33. A catheter as set forth in claim 32, wherein the sleeve is electrically conducting and forms a distal electrode.

34. A catheter as set forth in claim 32, wherein the distal end portion is electrically conducting and forms a distal electrode.

35. A catheter as set forth in claim 32, wherein the distal end portion has at least one cross-sectional change in outside diameter.

36. A catheter as set forth in claim 32, wherein the sleeve has at least one cross-sectional change in inside diameter.

37. A catheter as set forth in claim 32, wherein the distal end portion is divided into two and comprises a proximal sub-portion and a distal sub-portion, wherein a proximal end of the distal sub-portion projects over a partial length into the distal end of the proximal sub-portion or vice-versa and is connected over said partial length of one of the two sub-portions and respectively to the respective other sub-portion by a force-locking connection, a positively locking connection or a joint involving intimate bonding of the materials concerned.

38. A catheter as set forth in claim 37, wherein the sleeve encloses both parts of the distal end portion at least over a partial length where a distal part of the proximal sub-portion encloses a proximal part of the distal sub-portion.

39. A catheter as set forth in claim 32, wherein, at its distal end, the distal end portion is in the form of a tip which forms a tip at the distal end of the catheter.

40. A catheter as set forth in claim 39, wherein the tip comprises polyphenylsulfone (PPSU) or polyetheretherketone (PEEK).

41. A catheter as set forth in claim 39, wherein the tip is provided with an anti-adhesion coating.

42. A catheter as set forth in claim 39, wherein the tip has a conical, trocar-shaped, cylindrical or spherical end face.

43. A catheter as set forth in claim 39, wherein the tip has an outside diameter which narrows from an outside diameter of the flexible shaft tube at an angle of between 10°

and 20°

with respect to the longitudinal direction of the catheter towards the distal end.

44. A catheter as set forth in claim 32, further including a plastic material hose in the lumen of the flexible shaft tube, whereby the diameter of the catheter lumen is reduced to the inside diameter of the plastic hose.

45. A catheter as set forth in claim 32, wherein the lumen is of a diameter of between 0.65 mm and 1.6 mm.

46. A catheter as set forth in claim 44, wherein the plastic hose and the flexible shaft tube comprise an electrically insulating material.

47. A catheter as set forth in claim 44, wherein the plastic hose comprises polyimide (PI).

48. A catheter as set forth in claim 44, wherein the flexible shaft tube is fluid-tightly connected to the plastic tube by welding, adhesive or by a press connection.

49. A catheter as set forth in claim 32, wherein the flexible shaft tube comprises polyetheretherketone (PEEK).

50. A catheter as set forth in claim 32, wherein the flexible shaft tube has at least two passages for passing electric lines therethrough.

51. A catheter as set forth in claim 32, wherein the at least one electrode and the sleeve are at least two ring electrodes drawn on to the flexible shaft tube.

52. A catheter as set forth in claim 51, further including an annular insulator drawn on between the at least two electrodes.

53. A catheter as set forth in claim 52, wherein the annular insulator comprises PEEK.

54. A catheter as set forth in claim 32, wherein the flexible shaft tube has a length between 600 and 2000 mm.

55. A catheter as set forth in claim 32, wherein the flexible shaft tube of the catheter has an outside diameter less than or equal to 5 mm, preferably 1.8 mm.

56. A catheter as set forth in claim 32, further including a temperature sensor at a distal end of the catheter for detecting the catheter temperature or the tissue temperature in the proximity of the catheter.

57. A catheter as set forth in claim 32, wherein the distal end portion has a central axial through bore forming a distal end portion of the lumen and the distal mouth opening thereof.

58. A catheter as set forth in claim 57, wherein the distal mouth opening of the distal end portion has a diameter of between 0.65 and 2 mm.

59. A catheter as set forth in claim 32, wherein a lumen of the catheter is continuous therethrough from the proximal end to the distal end of the catheter and has proximal and distal mouth openings, the catheter being so designed that a guide wire can be introduced by way of the proximal mouth opening, advanced to the distal end through the lumen and issue again through the distal mouth opening.

60. A catheter as set forth in claim 57, wherein the distal end portion has an inside diameter which enlarges from the inside diameter of the lumen from a point between the proximal and distal ends of the end portion in the direction of the distal end of the distal end portion at an angle of between 15 and 85 degrees.

61. A catheter as set forth in claim 32, wherein the catheter is closed at a distal end.

62. A catheter as set forth in claim 61, further including a cooling system with a proximal feed and discharge flow means for a cooling medium in the catheter.

63. A method for electrosurgical treatment of body tissue in the lumen of a hollow organ, including the steps:

a) providing a catheter according to claim 32;

b) placing a guide wire in the lumen of the hollow organ;

c) pushing the catheter over the guide wire, while the guide wire remains in position;

d) advancing the catheter until at least one electrode has reached the desired position; and

e) applying high-frequency AC voltage to the at least one electrode.

64. A method for electrosurgical treatment of varicose veins, including the steps:

a) providing a catheter according to claim 32;

b) opening a desired blood vein;

c) introducing a guide wire into the opened vein;

d) pushing the catheter over the guide wire, introducing it into the opened vein and advancing it as far as the end of the vein;

e) providing a high-frequency AC voltage to the at least one electrode when the distal end of the catheter is correctly positioned;

f) retracting the catheter slowly in the proximal direction relative to the guide wire or together with the guide wire with a speed that is adapted to the geometry of the vein being treated and to the applied high-frequency AC voltage.

65. The method according to claim 64, whereby before applying high frequency AC voltage to the at least one electrode the blood of the vein is expelled from the vein with a cuff.

66. The method according to claim 64, whereby a cord is tensioned in parallel relationship with the catheter from the connecting element so that the end of the cord or a marked location on the cord outside the body of the patient is approximately level with the at least one electrode within the patient.

67. The method according to claim 64, wherein impedance between the at least one electrode and speed of withdrawal of the high-frequency catheter and also the magnitude of the high-frequency AC voltage is adapted to the respective requirements involved.

68. A method for constriction or sclerosis of the Fallopian tube, including the steps of:

a) providing a catheter according to claim 32;

b) introducing a guide wire and thereafter the catheter by means of a hysteroscope (endoscope for gynaecology) from an uterus into the Fallopian tube to be closed off;

c) advancing the catheter as far as the end of the Fallopian tube;

d) providing a high-frequency AC voltage to the at least one electrode when a distal end of the catheter is correctly positioned;

e) withdrawing the catheter while delivering a high-frequency current within a defined distance so that the coagulated region contracts in respect of diameter and closes as a result.

69. A method for treating obstructive tumors in the region of the bile duct (ductus choledochus), including the steps:

a) providing a catheter according to claim 32;

b) introducing a flexible endoscope, gastroscope or duodenoscope through the buccal cavity, the esophagus and the stomach, and positioning it with the distal end in front of the major papilla of the duodenum;

c) introducing a guide wire into the bile duct through its papilla and advancing it beyond the portion of the bile duct which is to be treated,

d) advancing the catheter over the guide wire through the working passage of the endoscope until the at least one electrode of the catheter is in the region of the bile duct that is to be treated;

e) applying a high-frequency AC voltage to the at least one electrode and thereby coagulating surrounding tissue.

70. The method according to claim 69, whereby at the end of the surgery a stent is fitted into the bile duct in order to prevent renewed obstruction by fibrin precipitation phenomena.