RF ablation and ultrasound catheter for crossing chronic total occlusions

• US 6,394,956 B1
• Filed: 02/29/2000
• Issued: 05/28/2002
• Est. Priority Date: 02/29/2000
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Kaveckis, Ryan, Chandrasekaran, Chandru V., Masters, Donald, Guo, Zihong, Pantages, Anthony J.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): Imam, Ali M.
• Application Number:
  US09/514,970
• Time in Patent Office: 819 Days
• Field of Search: 600/439,437,459,462,463,466,467,469,470,471 607/122 128/898
• US Class Current: 600/439
• 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 2017/003 Steerable
• CPC Class Codes: A61B 2018/00208 actively driven, e.g. by a motor
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/0041 Removal of thrombosis
• CPC Class Codes: A61B 2018/00541 Lung or bronchi
• CPC Class Codes: A61B 2018/144 Wire
• CPC Class Codes: A61B 2018/1861 with an instrument inserted into a body lumen or cavity, e.g. a catheter
• CPC Class Codes: A61B 2090/3782 transmitter or receiver in catheter or minimal invasive instrument
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61B 8/4461 Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe
• CPC Class Codes: A61F 9/0079 using non-laser electromagnetic radiation, e.g. non-coherent light or microwaves

Abstract

A combination catheter includes an ultrasound transducer and RF ablation electrode. The ultrasound transducer transmits ultrasound signals into and receives echo signals from a vessel. The echo signals are processed and used to produce an image of the tissue surrounding the catheter. A driveshaft rotates the ultrasound transducer to obtain a 360° view of the vessel wall. At the distal end of the driveshaft is an electrode. An RF generator is electrically coupled to the driveshaft to deliver RF energy to the electrode at the distal end of the driveshaft to ablate occluding material in the vessel. The electrode may have a variety of tip shapes including concave, roughened, or expandable configurations, depending on the size of the vessel and composition of the occluding material to be ablated. Alternatively, the RF ablation energy may be delivered to a guidewire that is used to route the ultrasound catheter through a patient'"'"'s vasculature. Finally, a steerable catheter can be used to further position the ultrasound catheter and ablation electrode in the vessel.

Claims

1. A system for treating occluded vessels, comprising:

an ultrasound catheter including;

at least one ultrasound transducer that directs ultrasonic energy into and receives corresponding echo signals from a vessel wall;

a conductive driveshaft that rotates the at least one ultrasound transducer to obtain a 360°

image of the vessel wall;

an electrode coupled to the distal end of the conductive driveshaft; and

an RF energy source that selectively applies RF ablation energy to the conductive driveshaft to deliver the RF ablation energy to the electrode.

2. The system of claim 1, wherein the at least one ultrasound transducer is fitted within the electrode and is positioned to direct ultrasound signals into and receive echo signals from a position in the vessel distal to the electrode.

3. The system of claim 1, wherein the electrode has a distal tip that is concave.

4. The system of claim 1, wherein the electrode has a distal tip that is hemispherical and roughened.

5. The system of claim 1, wherein the electrode has a distal tip that is expandable.

6. The system of claim 1, wherein the ultrasound catheter is routed through a steerable sheath.

7. A method of ablating an occlusion in a vessel, comprising:

advancing a catheter into the vessel near the area of the occlusion;

advancing a conductive driveshaft within the catheter, wherein the driveshaft rotates an imaging device for obtaining images of the occlusion and/or the vessel in the area near the occlusion, said drive shaft also having an electrode for delivery of ablation energy;

rotating said drive shaft to obtain 360-degree images of said occlusion and/or said vessel; and

applying ablation energy to said conductive drive shaft to be delivered to the occlusion by said electrode.