How is Cryoablation Performed?
How Is Cryoablation Performed?
Cryoablation is a treatment that uses a needle-like instrument through which liquid nitrogen circulates to treat cancer by freezing it until it is dead.
The goal of the cryoablation procedure is to kill the cancer as well as a narrow rim of normal tissue surrounding the cancer to ensure that the cancer is treated fully.
The cryoablation procedure is similar to the needle biopsy that is typically performed to diagnose a cancer.
The doctor will insert the cryoprobe like a needle until it rests in the middle of the cancerous area. While doing this, the doctor will use an ultrasound to guide insertion and precise positioning of the cryoprobe. Liquid nitrogen then flows through the cryoprobe to cause freezing of the tumor plus a surrounding tissue (Figure A).
The liquid nitrogen remains within the cryoprobe. The outer wall of the cryoprobe is insulated along its length except for the last few centimeters of the cryoprobe near the tip, where an uninsulated segment (Figure A, red arrows) of the cryoprobe causes freezing of the tumor and adjacent tissue.
Freezing usually lasts 6-8 minutes followed by a 10-minute thaw phase followed again by another 6-8 minutes of freezing.
The blue curve in Figure B shows the rate of tumor freezing with liquid nitrogen, which reaches a temperature of minus 180 degrees celsius in 13 minutes. Tumor killing begins at minus 40 Celsius).
After the second freeze, the cryoprobe is warmed and withdrawn from the breast. Pressure is held on the skin opening for a few minutes followed by application of a bandage.
Watch a narrated video of a cancer cryoablation procedure.
Dispensing Liquid Nitrogen prior to cryoablation procedure.
Inner structure of a Cryoprobe through which liquid nitrogen circulates.
Graph shows rate of cooling with Liquid Nitrogen (blue curve).