Method and apparatus for removing plaque from blood vessels using ultrasonic energy

• US 20040073244A1
• Filed: 08/06/2003
• Published: 04/15/2004
• Est. Priority Date: 10/05/1999
• Status: Active Grant

• Current Assignee: Cybersonics, Inc
• Original Assignee: OmniSonics Medical Technologies, Inc.
• Inventors: Rabiner, Robert A., Hare, Brad A.
• Granted Patent: US 6,866,670 B2
• Time in Patent Office: Days
• US Class Current: 606/159
• CPC Class Codes: A61B 17/00234 for minimally invasive surgery A61B17/0218, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence
• CPC Class Codes: A61B 17/22012 in direct contact with, or very close to, the obstruction or concrement for removing obstructions in blood vessels by laser A61B18/245
• CPC Class Codes: A61B 2017/00137 Details of operation mode
• CPC Class Codes: A61B 2017/00274 Prostate operation, e.g. prostatectomy, turp, bhp treatment
• CPC Class Codes: A61B 2017/22002 preventing restenosis
• CPC Class Codes: A61B 2017/22007 Cavitation or pseudocavitation, i.e. creation of gas bubbles generating a secondary shock wave when collapsing
• CPC Class Codes: A61B 2017/22008 used or promoted
• CPC Class Codes: A61B 2017/22015 with details of the transmission member
• CPC Class Codes: A61B 2017/22018 segmented along its length
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2017/293 with means preventing relative rotation between the shaft and the actuating rod
• CPC Class Codes: A61B 2017/320073 probe
• CPC Class Codes: A61B 2017/320084 Irrigation sleeves
• CPC Class Codes: A61B 2217/005 with suction drainage system
• CPC Class Codes: A61B 2217/007 with irrigation system

Abstract

A method and apparatus for removing plaque, fatty deposits, and other occlusions from blood vessels using ultrasonic energy. The method and apparatus has particular application in removing plaque from the carotid artery in a non-thermal manner. The apparatus is designed to have as small a cross-sectional profile as possible, therefore allowing the apparatus to be used in a minimally-invasive manner. As a result, the apparatus can be used in both surgical and outpatient treatment with minimal post-operative complications and minimal damage to areas other than the area of treatment. An ultrasonic probe may include aspiration channels on its outer surface. An aspiration sheath may surround the ultrasonic probe, such that the location of an aspiration port may be varied axially relative to the ultrasonic tip.

Claims

1. A method for removing plaque from a blood vessel using an ultrasonic energy, comprising the steps of:

inserting an ultrasonic probe into the blood vessel;

extending a portion of the ultrasonic probe to an area adjacent to the plaque on an inner surface of the blood vessel;

transmitting ultrasonic vibrations to the portion of the ultrasonic probe;

reducing the plaque to a particulate material by producing cavitation in a vicinity of the plaque.

2. A method of claim 1 wherein the ultrasonic vibrations are transmitted in an axial direction along the ultrasonic probe and in a direction transverse to an axial direction of the ultrasonic probe.

3. The method of claim 1 further comprising irrigating the plaque with a fluid before transmitting the ultrasonic vibrations to the portion of the ultrasonic probe.

4. The method of claim 1 further comprising aspirating the particulate material after reducing the plaque to the particulate material.

5. The method of claim 1 wherein the blood vessel is a carotid artery.

6. The method of claim 1 wherein the transmitting of the ultrasonic energy is at a power level sufficient to reduce the plaque to the particulate material having individual particles with a diameter at least as small as about 10 microns.

7. The method of claim 1 further comprising monitoring a location of the distal end of the ultrasonic probe in the blood vessel.

8. The method of claim 7 wherein the location of the distal end of the ultrasonic probe is monitored using ultrasound.

9. The method of claim 1 further comprising monitoring an amplitude of the ultrasonic probe within the blood vessel.

10. The method of claim 1 further comprising monitoring a temperature of the ultrasonic probe within the blood vessel.

11. The method of claim 1 wherein a distal portion of the ultrasonic probe is used to produce cavitation in the vicinity of the plaque.

12. The method of claim 1 wherein cavitation causes the plaque to emulsify.

13. A method for reducing plaque in a blood vessel comprising:

providing a flexible member comprising a proximal end, a distal end and a longitudinal axis between the proximal end and the distal end;

inserting the flexible member into the blood vessel;

moving the flexible member in the blood vessel and placing the flexible member in communication with the plaque; and

providing an ultrasonic vibration to the flexible member, creating a transverse ultrasonic vibration along at least a portion of the longitudinal axis of the flexible member with a plurality of anti-nodes along the flexible member.

14. The method of claim 13 wherein the flexible member is an ultrasonic probe.

15. The method of claim 13 further comprising reducing the plaque to a particulate material having a diameter less than about 10 microns.

16. The method of claim 13 further comprising generating the ultrasonic vibration with an ultrasonic vibration generator.

17. The method of claim 13 further comprising transmitting the ultrasonic vibration through an ultrasonic coupler and a series of transformer sections to amplify the ultrasonic vibration.

18. The method of claim 13 wherein the plurality of anti-nodes create a cavitation in a fluid surrounding the flexible member to ablate the plaque.

19. The method of claim 13 wherein an ultrasonic vibration generator produces the ultrasonic vibration in a range of about 20 kHz to about 80 kHz.

20. The method of claim 13 further comprising moving the flexible member in an axial direction within an aspiration sheath to move the distal end of the flexible member axially inwardly and axially outwardly relative to a distal end of the aspiration sheath.

21. The method of claim 13 further comprising controlling a temperature at a treatment site of the plaque with one or more irrigation ports engaged to an irrigation passage extending along the longitudinal axis of the flexible member.

22. The method of claim 13 wherein the flexible member comprises a flexibility allowing the flexible member to be articulated in the blood vessel.

23. The method of claim 13 wherein the flexible member comprises a flexibility to support the transverse ultrasonic vibration.

24. An ultrasonic medical device comprising:

a probe having a distal end, a proximal end and an axial length therebetween; and

a diameter of the probe that is tapered from the proximal end of the probe to the distal end of the probe,

wherein the probe can support a transverse ultrasonic vibration along at least a portion of the axial length of the probe to destroy plaque within a blood vessel along at least a portion of the axial length of the probe.

25. The ultrasonic medical device of claim 24 wherein the probe has a small cross sectional profile.

26. The ultrasonic medical device of claim 24 wherein the probe is axially movably mounted within an aspiration sheath.

27. The ultrasonic medical device of claim 24 further comprising a probe tip capable of moving axially inward and outward relative to a distal end of an aspiration sheath.

28. The ultrasonic medical device of claim 27 wherein the probe tip is a ball shaped projection from the distal end of the probe.

29. The ultrasonic medical device of claim 24 wherein the probe includes a groove for aspiration of a material from a treatment site.

30. The ultrasonic medical device of claim 24 wherein the probe vibrates in a direction transverse to at least a portion of the axial length of the probe.

31. The ultrasonic medical device of claim 24 wherein the transverse ultrasonic vibration of the probe provides a plurality of anti-nodes along at least a portion of the axial length of the probe.

32. The ultrasonic medical device of claim 31 wherein the plurality of anti-nodes are points of maximum transverse ultrasonic vibration along at least a portion of the axial length of the probe.

33. The ultrasonic medical device of claim 24 wherein a flexibility of the probe allows the probe to be articulated.

34. A medical device comprising:

a flexible probe having a distal end, a proximal end and an axial length therebetween; and

a probe tip extending from the distal end of the probe,

wherein the probe is capable of flexing to support a transverse ultrasonic vibration along at least a portion of the axial length of the probe.

35. The medical device of claim 34 wherein the flexible probe has a small cross sectional profile.

36. The medical device of claim 34 wherein the flexible probe is axially movably mounted within an aspiration sheath.

37. The medical device of claim 34 wherein the probe tip is capable of moving axially inward and outward relative to a distal end of an aspiration sheath.

38. The medical device of claim 34 wherein the probe tip is a ball shaped projection from the distal end of the flexible probe.

39. The medical device of claim 34 wherein the flexible probe includes a groove for aspiration of a material from a treatment site.

40. The medical device of claim 34 wherein the flexible probe vibrates in a direction transverse to at least a portion of the axial length of the flexible probe.

41. The medical device of claim 34 wherein the transverse ultrasonic vibration of the flexible probe provides a plurality of anti-nodes along at least a portion of the axial length of the flexible probe.

42. The medical device of claim 41 wherein the plurality of anti-nodes are points of maximum transverse ultrasonic vibration along at least a portion of the axial length of the flexible probe.

43. The medical device of claim 34 wherein a flexibility of the probe allows the probe to be articulated.