Radio frequency ablation system

• US 20020072740A1
• Filed: 12/11/2000
• Published: 06/13/2002
• Est. Priority Date: 12/11/2000
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Barry, Robert L., Guo, Zihong, Shuman, Brandon, Chandrasekaran, Verivada Chandru
• Granted Patent: US 6,554,827 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• 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 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/0041 Removal of thrombosis

Abstract

An RF ablation system includes a catheter and an RF electrode that delivers RF electrical energy to the site of an occlusion. The system includes a mechanism for minimizing the likelihood that RF electrical energy will be applied directly to the vessel wall. In one embodiment of the invention, the catheter includes a number of tissue expanding jaws to engage a vessel wall and push the vessel wall away from the electrode to shield vessel walls from the electrode. In yet another embodiment of the invention, the electrode has a spiraled distal end with a radius that is larger than the radius of the catheter, such that the electrode engages the vessel wall and pushes the wall away from a conducting portion of the electrode. The portion of the electrode that engages the vessel wall is preferably coated with an insulating material to prevent delivery of RF electrical energy directly to the vessel wall.

Claims

1. A system for removing deposits from a vessel, comprising:

a catheter;

an electrode routed within the catheter that delivers RF ablation energy to remove deposits within the vessel; and

a tissue expander that engages a portion of a vessel wall and moves it away from an area of the electrode that delivers the RF ablation energy to the deposits.

2. The system of claim 1, wherein the tissue expander includes a number of tissue expanding jaws that can be radially expanded.

3. The system of claim 2, wherein the tissue expanding jaws are moved radially outward by pull wires connected to the jaws.

4. The system of claim 2, wherein the tissue expanding jaws are made of a spring material that is biased radially outward.

5. A system for removing deposits from a vessel, comprising:

a catheter;

an energy delivery electrode that is routed within the catheter to a site of a deposit within a vessel and that delivers RF ablation energy to remove the deposits, the electrode having a spiraled radius at its distal end that exceeds a radius of the catheter at its widest point and that decreases distally wherein the spiraled portion of the electrode engages a portion of a vessel wall and moves it radially outward.

6. The system of claim 5, wherein the electrode is nonconductive where the spiraled portion of the electrode engages the vessel wall.

7. A system for removing deposits from a vessel comprising:

a catheter;

an RF energy electrode that is routed within the catheter to the deposits, the RF energy catheter including a center electrode and a proximal ring electrode that surrounds a portion of the center electrode, the ring electrode having a radius that is larger than a radius of the catheter such that the ring electrode engages a portion of a vessel wall and moves it away from the center electrode.