Cryoablation catheter and method of performing cryoablation

• US 5,147,355 A
• Filed: 09/23/1988
• Issued: 09/15/1992
• Est. Priority Date: 09/23/1988
• Status: Expired due to Term

• Current Assignee: Medtronic CryoCath LP (Medtronic Plc)
• Original Assignee: Brigham and Women's Hospital Incorporated
• Inventors: Wang, Paul, Friedman, Peter L., Cravalho, Ernest G.
• Primary Examiner(s): Yasko, John D.
• Assistant Examiner(s): CERMAK, ADAM
• Application Number:
  US07/249,343
• Time in Patent Office: 1,453 Days
• Field of Search: 606/20-26, 128/303.1, 128/362, 128/399-401, 128/DIG. 27, 604/113
• US Class Current: 606/23
• CPC Class Codes: A61B 18/02 by cooling, e.g. cryogenic techniques devices for cooling specific reflex points of the body within cell-life limits A61H39/06
• CPC Class Codes: A61B 2017/00039 Electric or electromagnetic phenomena other than conductivity, e.g. capacity, inductivity, Hall effect
• CPC Class Codes: A61B 2017/00292 mounted on or guided by flexible, e.g. catheter-like, means
• CPC Class Codes: A61B 2018/0212 using an instrument inserted into a body lumen, e.g. catheter

Abstract

A method and apparatus is provided for cryogenically ablating a predetermined portion of tissue in the body of a patient. Cryoablation is accomplished by a cryoblation catheter having a hollow shaft insertable into the blood vessel of a patient. The shaft has a closed tip portion and a fluid flow passage for directing a flow of cryogenic fluid to the tip. Cryogenic cooling is effected by a liquid-to-gas fluid phase change adjacent the catheter tip. Electrical signal activity may be monitored by an electrode formed integral with the tip to confirm treatment of the paper tissue site.

Claims

1. A method of cryogenically ablating a predetermined portion of tissue within a blood vessel of a patient, comprising the steps of:

inserting a catheter having a tip portion into the lumen of the blood vessel;

guiding said catheter to a predetermined portion of the patient'"'"'s body and positioning said tip portion adjacent tissue within the lumen of the blood vessel to be ablated;

directing a flow of cryogenic fluid to said tip portion;

effecting a cooling of said cryogenic fluid adjacent said tip portion; and

removing said fluid from said tip portion.

2. A method according to claim 1, wherein said step of directing said flow of cryogenic fluid comprises directing said fluid to said catheter tip through a first fluid flow passage formed in said catheter and said step of removing said fluid comprises directing said fluid through a second fluid flow passage formed in said catheter.

3. A method according to claim 1, further comprising the step of controlling said flow of cryogenic fluid remote from said catheter tip to vary the temperature and rate of cooling of said tip portion.

4. A method according to claim 3, further comprising the step of throttling said flow of cryogenic fluid to provide reversible cooling of said tissue adjacent said catheter tip portion.

5. A method according to claim 1, further comprising the step of sensing electrical activity from said predetermined portion of the body with a device integral with said tip.

6. A method according to claim 5, wherein the steps of sensing said electrical activity and ablating said tissue occur substantially simultaneously.