Ultrasonic device for tissue ablation and sheath for use therewith

• US 7,503,895 B2
• Filed: 02/24/2003
• Issued: 03/17/2009
• Est. Priority Date: 10/05/1999
• Status: Expired due to Fees

• Current Assignee: Cybersonics, Inc
• Original Assignee: OmniSonics Medical Technologies, Inc.
• Inventors: Rabiner, Robert A., Hare, Bradley A.
• Primary Examiner(s): Winakur; Eric F
• Assistant Examiner(s): Cheng; Jacqueline
• Application Number:
  US10/373,134
• Publication Number:
  US 20030176791A1
• Time in Patent Office: 2,213 Days
• Field of Search: 600/439, 600/459, 600/437, 606/169, 606/171
• US Class Current: 600/439
• 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 17/320068 using mechanical vibrations, e.g. ultrasonic A61B17/22012 takes precedence; dental tooth drilling devices operated by vibration A61C3/03; removing intra-ocular material using mechanical vibrations A61F9/00745
• 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 2017/320069 for ablating tissue
• CPC Class Codes: A61B 2017/32007 with suction or vacuum means
• CPC Class Codes: A61B 2017/320084 Irrigation sleeves
• CPC Class Codes: A61B 2017/320089 node location
• CPC Class Codes: A61B 2017/320098 with transverse or torsional motion
• CPC Class Codes: A61B 2018/00547 Prostate
• CPC Class Codes: A61B 2018/00982 combined with or comprising means for visual or photographic inspections inside the body, e.g. endoscopes
• CPC Class Codes: A61B 2217/005 with suction drainage system
• CPC Class Codes: A61B 2217/007 with irrigation system
• CPC Class Codes: A61M 1/85 : with gas or fluid supply means, e.g. for supplying rinsing fluids or anticoagulants for negative pressure wound therapy A61M1/92, A61M1/94; combined with tracheal tubes A61M16/0463; dental instruments with combined rinsing and aspirating A61C17/0208
• CPC Class Codes: A61N 2007/0008 : Destruction of fat cells
• CPC Class Codes: A61N 7/022 : intracavitary

Abstract

A transverse mode ultrasonic probe is provided which creates a cavitation area along its longitudinal length, increasing the working surface of the probe. Accessory sheaths are also provided for use with the probe to enable a user to select from features most suited to an individual medical procedure. The sheaths provide acoustic enhancing and aspiration enhancing properties, and/or can be used as surgical tools or as medical access devices, protecting tissue from physical contact with the probe.

Claims

1. An ultrasonic medical device for tissue ablation comprising:

an elongated probe having a proximal end, a distal end and at least two regions of differing cross sectional dimension, wherein a length of the elongated probe is configured to oscillate in a direction transverse to a longitudinal axis of the elongated probe to emit transverse ultrasonic energy along the length of the elongated probe so that a plurality of transverse nodes and transverse anti-nodes are formed along the length of the elongated probe; and

a sheath assembly at least partially surrounding the elongated probe, the sheath assembly comprising at least one sheath defining a fenestration between a proximal and distal end of the at least one sheath, the at least one sheath being configured to substantially dampen ultrasonic energy such that ultrasonic energy delivered by the elongated probe is focused toward a region adjacent the fenestration.

2. The device of claim 1, wherein the sheath assembly covers at least a portion of the elongated probe, the sheath assembly comprising a longitudinally extending structural wall that defines a longitudinally extending hollow interior for accommodating at least a portion of the elongated probe, wherein the longitudinally extending structural wall of the sheath assembly is substantially self supporting so that the longitudinally extending structural wall substantially maintains a same shape with the elongated probe disposed in the longitudinally extending hollow interior as without the elongated probe disposed in the longitudinally extending hollow interior.

3. The device of claim 1, wherein the sheath assembly is constructed to substantially prevent a transmission of cavitational energy generated by the elongated probe to a surrounding environment.

4. The device of claim 1, wherein the sheath assembly further comprises one or more devices capable of manipulating a tissue.

5. The device of claim 1, wherein the sheath assembly further comprises at least one reflective element configured to reflect ultrasonic energy.

6. The device of claim 1, wherein the sheath assembly further comprises at least one irrigation channel.

7. The device of claim 1, wherein the sheath assembly further comprises at least one aspiration channel.

8. The device of claim 1, wherein the sheath assembly further comprises at least one channel for delivering a therapeutic agent therethrough.

9. The device of claim 1, wherein the sheath assembly is adapted for use with an imaging system.

10. A method of modulating, focusing and directing a cavitational energy emitted from an ultrasonic probe vibrating in a direction transverse to a longitudinal axis of the ultrasonic probe for tissue ablation comprising:

enclosing at least a portion of the ultrasonic probe within a sheath assembly comprising a sheath defining at least one fenestration between a proximal end and a distal end of the sheath;

inserting the ultrasonic probe into a blood vessel;

guiding the ultrasonic probe and the sheath assembly into the blood vessel and to a site of an occlusion;

positioning the ultrasonic probe and the sheath assembly such that the at least one fenestration is in proximity with the occlusion;

providing an ultrasonic excitation signal to the ultrasonic medical device and transferring the ultrasonic excitation signal along a length of the ultrasonic probe to a flexible probe tip, thereby causing a transverse vibration of the length of the ultrasonic probe and the flexible probe tip and a generation of a plurality of transverse nodes and anti-nodes of the cavitational energy along the length of the ultrasonic probe and the flexible probe tip; and

controlling a selective transmission of cavitational energy through the at least one fenestration in the sheath, thereby directing the cavitational energy in an area of the occlusion within the blood vessel to cause fragmentation of the occlusion.

11. The method of claim 10, wherein the sheath assembly is capable of partially shielding tissue at a site of a surgical procedure from the ultrasonic probe.

12. The method of claim 10, further comprising removing at least one fragment of the occlusion through an aspiration conduit of the sheath assembly.

13. The method of claim 10, further comprising supplying an irrigating fluid to the site of the occlusion through an irrigation conduit of the sheath assembly.

14. The method of claim 10, further comprising delivering a therapeutic agent through a conduit of the sheath assembly.

15. The method of claim 10, further comprising positioning the ultrasonic probe proximal to the occlusion using an imaging system.

16. The method of claim 10, comprising manipulating tissue with a tissue manipulation device of the sheath assembly.

17. The method of claim 10, further comprising shielding an ultrasound energy emitted from the ultrasonic probe with the sheath assembly, and visualizing a surgical site with an ultrasound imaging system, the shielding of the ultrasound energy increasing the resolution of the surgical site visualized by the ultrasound imaging system.

18. The method of claim 10, further comprising introducing the sheath assembly from an exterior of a patient to the site of the occlusion, and introducing the ultrasonic probe into the sheath assembly and guiding the ultrasonic probe to a surgical site.

19. A medical device, comprising:

an ultrasonic probe configured to emit ultrasonic energy transversely along a portion of the ultrasonic probe; and

a sheath comprising a proximal end and a distal end, the sheath at least partially surrounding the ultrasonic probe and defining a fenestration between the proximal and distal ends of the sheath, the sheath being configured to substantially dampen ultrasonic energy such that ultrasonic energy delivered by the medical device is focused toward a region adjacent the fenestration.

20. The medical device of claim 19, wherein the sheath defines a plurality of fenestrations between the proximal and distal ends of the sheath.

21. The medical device of claim 19, wherein the fenestration extends from a proximal end of the sheath to a distal end of the sheath.

22. The medical device of claim 19, further comprising at least one reflective element disposed on an interior surface of the sheath.

23. The medical device of claim 19, wherein the sheath is at least partially surrounded by a second, retractable sheath.

24. The medical device of claim 19, wherein the sheath is constructed to substantially prevent ultrasonic energy from passing therethrough.

25. The medical device of claim 24, wherein the sheath comprises one or more materials that are capable of dissipating ultrasonic energy.