ULTRASOUND CATHETER HAVING IMPROVED DISTAL END

• US 20120283743A1
• Filed: 07/13/2012
• Published: 11/08/2012
• Est. Priority Date: 11/07/2006
• Status: Active Grant

• Current Assignee: Flowcardia Inc. (Becton, Dickinson & Co)
• Original Assignee: Flowcardia Inc. (Becton, Dickinson & Co)
• Inventors: Nita, Henry
• Granted Patent: US 9,629,643 B2
• Time in Patent Office: Days
• US Class Current: 606/128
• 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 2017/22014 the ultrasound transducer being outside patient's body; with an ultrasound transmission member; with a wave guide; with a vibrated guide wire not applied in A61B17/22012
• CPC Class Codes: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61B 2017/22039 eccentric
• CPC Class Codes: A61B 2017/22089 Gas-bubbles
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61M 25/0068 Static characteristics of the catheter tip, e.g. shape, atraumatic tip, curved tip or tip structure
• CPC Class Codes: A61M 25/0069 Tip not integral with tube
• CPC Class Codes: A61M 25/0082 Catheter tip comprising a tool

Abstract

An ultrasound catheter has an elongate flexible catheter body having a lumen extending longitudinally therethrough, and an ultrasound transmission member extending longitudinally through the lumen of the catheter body. The ultrasound transmission member has a proximal end that is coupled to a separate ultrasound generating device, and a distal tip that is attached to the distal end of the ultrasound transmission member and which is located at the distal end of the catheter body. The distal tip has at least one dimensional step. The ultrasound transmission member is directly attached to the catheter body and/or to a guidewire tube, either directly or via an attachment device. The catheter has an additional radiopaque marker positioned on the distal end the catheter.

Claims

1. A method of ablating tissue in a vessel, the method comprising:

positioning a catheter in the vessel such that a distal end of an ultrasound transmission member passing through the catheter is adjacent to the tissue, the distal end having a tip surrounded by an intermediate member, a proximal end and a distal end of the intermediate member each having an inner diameter that is less than a maximum diameter of the tip;

transmitting ultrasound energy to the tip through the ultrasound transmission member; and

passing an irrigation fluid through the catheter to dissipate heat away from the ultrasound transmission member.

2. The method of claim 1, wherein a proximal section of the catheter has a diameter that is greater than a diameter of a distal section of the catheter.

3. The method of claim 1, wherein the ultrasound transmission member is coaxially disposed with the catheter.

4. The method of claim 1, wherein the tip has at least one radial dimensional step and wherein the intermediate member is seated on the at least one radial dimensional step.

5. The method of claim 1 further comprising coupling the ultrasound transmission member to an ultrasound generating device.

6. A method of ablating tissue in a vessel, the method comprising:

providing an ultrasound catheter comprising;

an elongate flexible catheter body having a proximal end, a distal end, and at least one lumen extending longitudinally therethrough;

an ultrasound transmission member extending longitudinally through the lumen of the catheter body, the ultrasound transmission member having a proximal end and a distal end;

a tip coupled to the distal end of the ultrasound transmission member, wherein the tip has at least one radial dimensional step having a contact surface facing away from the ultrasound transmission member and in a distal direction; and

an intermediate member attached to the catheter body and having a contact surface facing at least a portion of the contact surface on the tip and in a proximal direction.

7. The method of claim 6 further comprising positioning the tip against an ablation target.

8. The method of claim 7 further comprising creating a pilot entry lumen in the ablation target with the tip.

9. The method of claim 6 further comprising delivering ultrasound energy to the tip through the ultrasound transmission member.

10. The method of claim 9, wherein the contact surface of the intermediate member is disposed so as to contact the contact surface of the tip to prevent the tip from becoming dislodged from the catheter body at least when the ultrasound energy is delivered to the tip.

11. The method of claim 6, wherein a cross-sectional area through the tip taken on a distal side of the contact surface of the tip is less than a cross-sectional area through the tip at the contact surface of the tip.

12. The method of claim 6, wherein a cross-sectional area of the intermediate member at a location on a proximal side of the contact surface of the intermediate member is less than a cross-sectional area of the intermediate member at the contact surface of the intermediate member.

13. The method of claim 6, wherein a proximal section of the catheter body has a diameter that is greater than a diameter of a distal section of the catheter body.

14. The method of claim 6 further comprising positioning a cap, which is coupled to the tip, against an ablation target.

15. The method of claim 6 further comprising coupling the proximal end of the ultrasound transmission member to an ultrasound generating device.

16. The method of claim 6 further comprising infusing a fluid through the lumen of the body.

17. A method of ablating tissue in a vessel, comprising:

positioning a catheter in the vessel such that a distal end of an ultrasound transmission member passing through the catheter is adjacent to the tissue, the distal end having a tip and a cap, the cap being coupled to the tip by an attachment structure to at least partially define a groove therebetween, an intermediate member being attached to the catheter with at least a portion of the intermediate member being disposed within the groove;

transmitting ultrasound energy to the cap through the ultrasound transmission member; and

passing an irrigation fluid through the catheter to dissipate heat away from the ultrasound transmission member.

18. The method of claim 17, wherein a proximal section of the catheter has a diameter that is greater than a diameter of a distal section of the catheter.

19. The method of claim 17, wherein the ultrasound transmission member is coaxially disposed with the catheter.

20. The method of claim 17 further comprising coupling the ultrasound transmission member to an ultrasound generating device.