Freezing abnormal cells removes and stops growth
Cryosurgery or cryotherapy involves using extreme cold—usually liquid nitrogen or sometimes carbon dioxide or argon gas—to "freeze off" abnormal cells, such as a tumor. The therapy is commonly used externally for skin growths, such as warts and skin tags, and cancerous cells such as basal and squamous cell carcinoma. It may be used internally for abnormal cell growth and tumors that are difficult to treat with other therapies or because the patient is unable to tolerate other types of treatments. Cryosurgery is commonly used to treat cancers of the prostate and the cervix as well as retinoblastoma, a type of eye cancer often diagnosed during childhood.
For external applications, the doctor may use a cotton tip dipped in liquid nitrogen to apply to the specific treatment area. If used internally, a cryoprobe is inserted through an incision (cut) in the skin or through the rectum, vagina or urethra, depending on the type of cancer being treated. An MRI or ultrasound helps the doctor see where to guide the cryoprobe. One it reaches the area of abnormal cell growth, the probe produces ice crystals which freeze the abnormal cells with little effect on the surrounding tissue.
Depending on the type of procedure, you may only need local anesthesia or a combination of local and general (in which you will be asleep during the procedure). Or you may have IV anesthesia that puts you in a drowsy state during which you won't feel anything.
Cryosurgery is generally not painful though you may experience some discomfort at the treatment or incision site. If you are having cervical cryotherapy, you may experience some cramping and pressure as the cryoprobe is guided to the cells being treated. For external treatments, the spot that was treated will scab over and generally falls off within a few days. If internal, the damaged tissue that has now been frozen will thaw and get absorbed within the body.
There is no special preparation for cryosurgery but if you are having general anesthesia your doctor will advise you to not eat or drink anything for 12 hours before your procedure. The details of your procedure and what to expect before and after will be discussed with you in advance.