Cryosurgery

Cryosurgery is also called cryoablation, cryosurgical ablation or cryotherapy. It uses extreme cold (liquid nitrogen or carbon dioxide) to freeze and destroy abnormal cells or tissue.

In the past, cryosurgery was mainly used to treat tumours on the outside of the body. Today, it is also being tested and used as a treatment for some tumours inside the body.

Cryosurgery is mainly used to treat:

• actinic keratosis (a precancerous condition of the skin)
• skin cancer
• precancerous conditions of the cervix such as cervical intraepithelial neoplasia (CIN) and carcinoma in situ of the cervix
• hepatocellular carcinoma (a type of liver cancer) – when surgery is not possible
• cancer that has spread to the liver from another part of the body (called liver metastases)
• retinoblastoma (a type of childhood eye cancer)

Where cryosurgery is done depends on the area being treated and your overall health. You may have cryosurgery as an outpatient (you will go home the same day) or you may need to stay in the hospital.

The preparations for cryosurgery depend on the area of the body being treated. If it is being used to treat a tumour on the outside of the body, you might not need to do any specific preparation. If cryosurgery is being used to treat a tumour inside the body, you may need to do the same things you would do to prepare for traditional open surgery.

Cryosurgery can be combined with other cancer treatments, such as open surgery, chemotherapy or radiation therapy. You may be given an anesthetic or sedative before the surgery. Depending on the area treated, special warming blankets may be used during the surgery.

An extremely cold gas (liquid nitrogen or carbon dioxide) can be sprayed directly on the tumour. Sometimes a probe that gets very cold is placed on the tumour. The gas or probe freezes the area. The area is allowed to thaw, and then it is frozen again. The freeze-thaw cycle may need to be repeated 2 or 3 times.

An ultrasound may be used to find the tumour and monitor the freezing process. The doctor makes an incision, or cut, through the skin to reach the tumour. The tip of a metal tube (called a cryoprobe) is passed through the incision and into the tumour. More than one cryoprobe may be needed to treat large tumours.

An extremely cold gas (liquid nitrogen or carbon dioxide) is passed through the cryoprobe to the tumour. The tissue is frozen and an ice ball forms. After the freezing is complete, the cryoprobe is warmed and removed from the tumour. The frozen tissue thaws and forms scar tissue. The freeze-thaw cycle may need to be repeated.

Side effects can happen with any type of treatment, but everyone’s experience is different. Some people have many side effects. Other people have few or none at all. Side effects of cryosurgery will depend mainly on:

• the area treated
• the size of the tumour
• damage to nearby tissue
• your overall health

Side effects can develop any time during, immediately after or a few days or weeks after cryosurgery. Sometimes late side effects develop months or years after cryosurgery. Most side effects will go away on their own or can be treated, but some may last a long time or become permanent.

Tell your healthcare team if you have these side effects or others you think might be from your cryosurgery. The sooner they are aware of any problems, the sooner they can suggest ways to help you deal with them.

Pain often occurs because of trauma to the tissue during cryosurgery. It may take time for pain to go away after cryosurgery, depending on the area treated and how you heal or cope with pain. Pain-relieving medicines may be offered to control pain. Check with your doctor if pain doesn’t go away or pain medicines do not relieve it.

Find out more about pain.

Surgeons often use small cuts to reach internal organs so they can be treated with cryosurgery. Using small cuts generally helps limit bleeding. But heavy bleeding can occur after cryosurgery to treat liver tumours.

The healthcare team will closely monitor you for signs of internal bleeding after cryosurgery to treat liver tumours. Tell your doctor or healthcare team if you have heavy bleeding after cryosurgery.

Infection is a temporary side effect that may occur after cryosurgery. Tell your doctor or the healthcare team if you have signs of infection, such as unusual drainage, fever or chills.

Find out more about infection.

Sometimes your body temperature can go down a little during cryosurgery to treat liver tumours. The healthcare team will monitor your body temperature during and after the procedure.

Being prepared for a test or procedure can lower anxiety, increase cooperation and help the child develop coping skills. Parents or caregivers can help prepare children by explaining to them what will happen, including what they will see, feel and hear during the procedure.

How you help a child prepare for cryosurgery depends on their age and experience. Find out more about helping children cope with tests and treatment.

To make the decisions that are right for you, ask your healthcare team questions about cryosurgery.