What is Cryotherapy or Cryosurgery?

Cryotherapy, also called cryosurgery, cryoablation or targeted cryoablation therapy, refers to the application of extreme cold to destroy diseased tissue, including cancer cells.

What are some common uses of the procedure?
Since the 1960s, cryotherapy has been used to destroy skin tumors, precancerous skin moles, nodules, skin tags or unsightly freckles. It also has been used to destroy retinoblastomas, a childhood cancer of the retina. With the improvement of imaging techniques and the development of devices to better control extreme temperatures, physicians have begun to perform cryotherapy for prostate, liver and cervical dysplasia, especially if surgery is not possible.

How should I prepare for the procedure?
No special preparation is needed to undergo cryotherapy, although some physicians recommend ibuprofen (400 mg) a half-hour before the procedure to relieve minor discomfort.
What does the equipment look like?
Cryotherapy is carried out by using a cryoprobe, a thin wand-like device with a handle or trigger, attached via tubing to a source of nitrogen or argon, which super-cools the probe tip.

How does the procedure work?
Living tissue, healthy or diseased, cannot withstand extremely cold conditions and dies from:

Ice within the cell. At approximately -40°C (-40°F) or less, intracellular lethal-ice crystals begin to form that will tear apart almost any cell.

Bursting from swelling or shrinking. If ice forms only outside the cell, osmosis—the movement of a solution through the membrane of a cell—causes the cell to shrink as it gives up water to replace the water that has turned to ice. Then, as the area thaws, water rushes into the shrunken cell and causes it to burst. For this reason, cryotherapy usually consists of a series of steps in which tumors are repeatedly frozen and thawed.

Loss of blood supply. Cells die when their blood supply is choked off by ice forming within small tumor vessels, causing clotting. Since the average blood-clotting time is approximately 10 minutes, the extreme cold is maintained for at least 10 minutes unless tumor temperatures indicate that lethal-ice temperatures have been reached.

Once the cells are destroyed, components of the immune system—primarily the white blood cells—clear out the dead tissue. There is some evidence to suggest that this procedure also stimulates the immune system to attack remaining cancer cells.

How is the procedure performed?
For external masses, liquid nitrogen is applied directly with a cotton swab or spray device. For internal tumors, liquid nitrogen or argon gas is circulated through the cryoprobe, which comes into contact with the diseased tissue.