Self-expanding cooling electrode for renal nerve ablation

Patent metadata

Field	Value
Publication number	US-9028485-B2
Application number	US-201113243105-A
Country	US
Kind code	B2
Filing date	Sep 23, 2011
Priority date	Nov 15, 2010
Publication date	May 12, 2015
Grant date	May 12, 2015

Abstract

A metallic tube arrangement includes an electrode region configured to expand radially and contract radially in response to increasing and decreasing a temperature at the electrode region, respectively. The electrode region is configured for intravascular deployment and delivery of high frequency energy to target tissue of a target vessel of the body. The electrode region is configured to expand radially to a diameter sufficient to contact an inner wall of the target vessel in response to a decrease in electrode region temperature and to contract radially to a diameter smaller than a diameter of the target vessel in response to an increase in electrode region temperature.

First claim

What is claimed is:

1. An apparatus, comprising:
a metallic tube arrangement comprising a proximal end, a distal end, an inlet, and an outlet, the distal end comprising a coil section and the proximal end comprising the inlet adapted to receive thermal transfer fluid, at least the coil section dimensioned for deployment within a target vessel;
the coil section configured to expand radially to a diameter sufficient to contact an inner wall of the target vessel in response to receiving cooled thermal transfer fluid;
at least a portion of the coil section defining an electrode configured to deliver high frequency energy to target tissue, the proximal end of the metallic tube arrangement configured to electrically couple to an electrical energy generator; and
the coil section configured to contract radially to a diameter smaller than an inner wall of the target vessel in response to removal of the cooled thermal transfer fluid via the outlet.

2. The apparatus of claim 1 , further comprising a sheath comprising a flexible shaft having a proximal end, a distal end, a length, and a lumen extending between the proximal and distal ends, the length of the shaft sufficient to access the target vessel from a percutaneous access location, and the lumen dimensioned to receive the metallic tube arrangement.

3. The apparatus of claim 1 , wherein:
the coil section is configured to deliver high frequency energy to the target tissue sufficient to ablate the target tissue; and
the coil section is configured to receive the cooled thermal transfer fluid at a temperature that provides protective cooling to the inner wall of the target vessel and that causes radial expansion of the coil section.

4. The apparatus of claim 1 , wherein the target vessel comprises a renal artery, and the target tissue comprises perivascular tissue including renal nerves.

5. The apparatus of claim 1 , further comprising:
a supply tube fluidly coupled to the inlet of the tube arrangement and having a length of the shaft sufficient to access the target vessel from the percutaneous access location; and
a return tube fluidly coupled to the outlet of the tube arrangement and having a length of the shaft sufficient to access the target vessel from the percutaneous access location.

6. The apparatus of claim 1 , wherein:
the thermal transfer fluid comprises a biocompatible thermal transfer fluid; and
the outlet of the tube arrangement is adapted to expel spent biocompatible thermal transfer fluid into blood flowing through the target vessel.

7. The apparatus of claim 1 , wherein the tube arrangement comprises a phase-change cryothermal cooling arrangement.

8. The apparatus of claim 1 , wherein the coil section is formed of a single layer of a thermal memory alloy.

9. The apparatus of claim 1 , wherein the coil section defines a two-sided bimetallic structure.

10. The apparatus of claim 1 , wherein the coil section comprises asymmetric walled tubing with at least two layers of metals having differing thermal expansion properties.

11. The apparatus of claim 1 , wherein the coil section further comprises thermal insulation covering portions of the coil section facing away from the inner wall of the target vessel.

12. The apparatus of claim 1 , wherein the electrode is configured to deliver radiofrequency energy to the target tissue.

13. The apparatus of claim 1 , wherein the coil section comprises one or more insulated sections and one or more exposed sections, the one or more exposed sections defining one or more electrodes.

14. An apparatus, comprising:
a metallic tube arrangement comprising an electrode region configured to expand radially and contract radially in response to increasing and decreasing a temperature at the electrode region, respectively, the electrode region configured for intravascular deployment and delivery of high frequency energy to target tissue of a target vessel of the body;
the electrode region configured to expand radially to a diameter sufficient to contact an inner wall of the target vessel in response to a decrease in electrode region temperature; and
the electrode region configured to contract radially to a diameter smaller than a diameter of the target vessel in response to an increase in electrode region temperature.

15. The apparatus of claim 14 , further comprising a sheath comprising a flexible shaft having a proximal end, a distal end, a length, and a lumen extending between the proximal and distal ends, the length of the shaft sufficient to access the target vessel from a percutaneous access location, and the lumen dimensioned to receive the metallic tube arrangement.

16. The apparatus of claim 14 , wherein:
the electrode region further comprises a fluid channel;
the electrode region configured to expand radially to the diameter sufficient to contact the inner wall of the target vessel in response to communicating cooled thermal transfer fluid through the fluid channel; and
the electrode region configured to contract radially to the diameter smaller than the target vessel diameter in response to terminating communication of cooled thermal transfer fluid through the fluid channel.

17. The apparatus of claim 14 , wherein:
the electrode region is configured to deliver high frequency energy to the target tissue sufficient to ablate the target tissue; and
the electrode region is configured to provide protective cooling to the inner wall of the target vessel.

18. The apparatus of claim 14 , wherein the target vessel comprises a renal artery, and the target tissue comprises perivascular tissue including renal nerves.

Assignees

• Edmunds Kevin
• Jenson Mark L
• Boston Scient Scimed Inc

Inventors

• Edmunds Kevin
• Jenson Mark L

Classifications

• A61B2018/1435

  Spiral · CPC title

• A61B2018/00023

  closed, i.e. without wound contact by the fluid · CPC title

• A61B2018/00642

  with feedback, i.e. closed loop control · CPC title

• A61B2018/00577

  Ablation · CPC title

• A61B2018/00791

  Temperature · CPC title