RF method for controlled depth ablation of soft tissue

• US 5,785,705 A
• Filed: 10/24/1995
• Issued: 07/28/1998
• Est. Priority Date: 10/11/1994
• Status: Expired due to Fees

• Current Assignee: Oratec Interventions Incorporated (Smith & Nephew PLC)
• Original Assignee: Oratec Interventions Incorporated (Smith & Nephew PLC)
• Inventors: Baker, James
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US08/547,510
• Time in Patent Office: 1,008 Days
• Field of Search: 606/32, 606/41, 606/46, 606/48, 606/50, 606/98, 606/99, 606/113, 606/116
• US Class Current: 606/32
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 18/1485 having a short rigid shaft for accessing the inner body through natural openings
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00053 Mechanical features of the instrument of device
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/126 bipolar
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2218/002 Irrigation

Abstract

An RF ablation apparatus has a delivery catheter with a delivery catheter lumen and a delivery catheter distal end. A first RF electrode is positioned in the delivery catheter lumen. The first RF electrode has a distal end, RF conductive surface, and a lumen. A second RF electrode has a distal end. The second RF electrode is at least partially positioned in the lumen of the first catheter, with its distal end positioned at the exterior of the first RF electrode distal end. Additionally, the second RF electrode distal end has a geometry that permits it to be substantially a groundpad. The distal end of the first RF electrode is moved in a direction away from the second RF electrode distal end to create a painting effect of an ablation band or line between the two distal ends. Alternatively, the distal end of the second RF electrode can be moved in a direction away from the distal end of the first RF electrode. An RF insulative sleeve or coating is placed or positioned along a second RF electrode conductive surface where it is substantially adjacent to the first electrode conductive surface. An RF power source is coupled to the first and second RF electrodes.

Claims

1. A method of ablating a tissue surface, comprising:

providing an RF ablation device including, a delivery catheter, a first RF electrode at least partially positioned in a lumen of the delivery catheter, and a second RF electrode positioned at least partially in the first RF electrode, a distal end of the second RF electrode having a distal end that is substantially a groundpad; and

moving a distal end of the first RF electrode in a direction away from the distal end of the second RF electrode to create an ablation line along a selected tissue site between the second RF electrode distal end and the first electrode distal end.

2. The method of claim 1, wherein the step of moving a distal end of the first RF electrode is performed multiple times.

3. The method of claim 1, wherein the step of providing an RF ablation device further includes providing an RF ablation device wherein the distal end of the second electrode has substantially no sharp edges.

4. The method of claim 3, wherein the step of providing an RF ablation device further includes providing an RF ablation device wherein at least a portion of the distal end of the first electrode has a sharp edge.

5. The method of claim 1, wherein the tissue includes collagen fibers.

6. The method of claim 5, further comprising:

pulling the distal end of the first electrode away from the distal end of the second electrode to provide a controlled shrinkage of the collagen fibers.

7. The method of claim 1, wherein the tissue is tissue associated with a knee.

8. The method of claim 1, wherein the tissue is tissue associated with a disc.

9. The method of claim 1, wherein the tissue is tissue associated with a shoulder.

10. The method of claim 1, wherein the tissue is tissue associated with a joint capsule.