Cryoablation is a process that uses extreme cold to destroy tissue. Cryoablation is performed using hollow needles (cryoprobes) through which cooled, thermally conductive, fluids are circulated. Cryoprobes are positioned adjacent to the target in such a way that the freezing process will destroy the diseased tissue.
Once the probes are in place, the attached cryogenic freezing unit removes heat from ("cools") the tip of the probe and by extension from the surrounding tissues. Ablation occurs in tissue that has been frozen by at least three mechanisms:
- formation of ice crystals within cells thereby disrupting membranes, and interrupting cellular metabolism among other processes;
- coagulation of blood thereby interrupting blood flow to the tissue in turn causing ischemia and cell death; and
- induction of apoptosis, the so-called programmed cell death cascade.
The most common application of cryoablation is to ablate solid tumors found in the lung, liver, breast, kidney and prostate. The use in prostate and renal cryoablation are the most common. Although sometimes applied in cryosurgery through laparoscopic or open surgical approaches, most often cryoablation is performed percutaneously (through the skin and into the target tissue containing the tumor) by a medical specialist, such as an interventional radiologist. The term is from cryo-ablation.