Cryosurgery is the use of extreme cold in surgery to destroy abnormal or diseased tissue; thus, it is the surgical application of cryoablation. The term comes from the Greek words cryo.
It is a proceedure of destruction of tissue by application of extreme cold; silver nitrate and solid carbon dioxide are commonly used. Uses include treatment of certain malignant lesions of the skin and mucous membranes, early removal of malignant lesions of the uterine cervix, and treatment of tumors that cannot be handled with traditional surgical techniques.
Cryosurgery has been historically used to treat a number of diseases and disorders, especially a variety of benign and malignant skin conditions.
Cryotherapy procedures are usually performed in the doctor’s office.
Warts, moles, skin tags, solar keratoses, Morton’s neuroma and small skin cancers are candidates for cryosurgical treatment. Several internal disorders are also treated with cryosurgery, including liver cancer, prostate cancer, lung cancer, oral cancers, cervical disorders and, more commonly in the past, hemorrhoids. Soft tissue conditions such as plantar fasciitis (jogger’s heel) and fibroma (benign excrescence of connective tissue) can be treated with cryosurgery. Generally, all tumors that can be reached by the cryoprobes used during an operation are treatable. Although found to be effective, this method of treatment is only appropriate for use against localized disease, and solid tumors larger than 1 cm. Tiny, diffuse metastases that often coincide with cancers are usually not affected by cryotherapy.
Cryosurgery works by taking advantage of the destructive force of freezing temperatures on cells. When their temperature sinks beyond a certain level ice crystals begin forming inside the cells and, because of their lower density, eventually tear apart those cells. Further harm to malignant growth will result once the blood vessels supplying the affected tissue begin to freeze.
Specific examples include nerve irritation between the ribs (intercostal neuralgia), cluneal nerve entrapment, ilioinguinal neuroma, hypogastric neuromas, lateral femoral cutaneous nerve entrapment, and interdigital neuromas. Many forms of nerve entrapment can often be treated with cryotherapy.
Method of doing:
A common method of freezing lesions is using liquid nitrogen as the cooling solution. This ?196 °C (?321 °F) cold liquid may be sprayed on the diseased tissue, circulated through a tube called a cryoprobe, or simply dabbed on with a cotton or foam swab.
Carbon dioxide is also available as a spray and is used to treat a variety of benign spots. Less frequently, doctors use carbon dioxide “snow” formed into a cylinder or mixed with acetone to form a slush that is applied directly to the treated tissue.
Recent advances in technology have allowed for the use of argon gas to drive ice formation using a principle known as the Joule-Thomson effect. This gives physicians excellent control of the ice, and minimizing complications using ultra-thin 17 gauge cryoneedles.
A mixture of dimethyl ether and propane is used in some “freeze spray” preparations such as Dr. Scholl’s Freeze Away. The mixture is stored in an aerosol spray type container at room temperature and drops to ?41 °C (?42 °F) when dispensed. The mixture is often dispensed into a straw with a cotton-tipped swab. Similar products may use tetrafluoroethane or other substances.
A number of medical supply companies have developed cryogen delivery systems for cryosurgery. Most are based on the use of liquid nitrogen, although some employ the use of proprietary mixtures of gases that combine to form the cryogen.
In cancer treatment
Cryosurgery is also used to treat internal and external tumors as well as tumors in the bone. To cure internal tumors, a hollow instrument called a cryoprobe is used, which is placed in contact with the tumor. Liquid nitrogen or argon gas is passed through the cryoprobe. Ultrasound or MRI is used to guide the cryoprobe and monitor the freezing of the cells. This helps in limiting damage to adjacent healthy tissues. A ball of ice crystals forms around the probe which results in freezing of nearby cells. When it is required to deliver gas to various parts of the tumor, more than one probe is used. After cryosurgery, the frozen tissue is either naturally absorbed by the body in the case of internal tumors, or it dissolves and forms a scab for external tumors.
Your preparation for cryosurgery depends on the type of cryosurgery being performed. Cryosurgery for skin cancer, which is the main reason cryosurgery is used, requires little preparation on your part.
If your doctor is treating an internal organ with cryosurgery, you’ll probably be given the same instructions that you’d get before traditional surgery. You’ll be asked to fast for 12 hours beforehand and arrange for a ride home from the procedure.
Before the procedure, tell your doctor if you have an allergy to anesthesia, as well as any and all medicine you’re taking, including over-the-counter medications and nutritional supplements.
Your doctor will provide you with complete instructions for preparing for the surgery. It’s important that you follow them.
Your doctor will place liquid nitrogen on your skin using a cotton swab or spray. A numbing medicine may be used to prevent any pain or discomfort.
If an internal area is being treated, your surgeon will use a scope, which is a flexible tube that can fit into various openings in your body, such as the urethra, rectum, or a surgical incision. The liquid nitrogen is fed to the area under treatment and applied to the targeted cells. The cells freeze, die, and then will be slowly absorbed by your body.
Your doctor will use imaging equipment, such as an ultrasound, as a guide for carrying out the procedure.
Cryosurgery is a minimally invasive procedure, and is often preferred to more traditional kinds of surgery because of its minimal pain, scarring, and cost; however, as with any medical treatment, there are risks involved, primarily that of damage to nearby healthy tissue. Damage to nerve tissue is of particular concern.
Patients undergoing cryosurgery usually experience redness and minor-to-moderate localized pain, which most of the time can be alleviated sufficiently by oral administration of mild analgesics such as ibuprofen, codeine or acetaminophen (paracetamol). Blisters may form as a result of cryosurgery, but these usually scab over and peel away within a few days.
While cryotherapy can reduce unwanted nerve irritation, it sometimes can leave the tissue affected with unusual sensations, such as numbness or tingling, or with redness and irritation of the skin. But these effects are generally temporary.
Cryosurgery does have risks, but they’re considered lower than other cancer treatments, such as surgery and radiation.
The risks associated with cryosurgery include:
*damage to nearby healthy tissue or vessels
*a loss of sensation if nerves are affected
*white skin at the site of the surgery