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NEW METHODS: CRYOSURGERY

Cutting with Cold

Cryosurgery is surgery by freezing. Normal surgery involves cutting through tissue to reach and remove abnormal masses. In routine procedures it is usually necessary to remove some normal tissue at the edges of the surgical field. The body heals after surgery by scarring both internal and external tissues. Cryosurgery may involve an initial incision with a knife to reach an area of interest, but the main difference is the use of a precise freezing probe. A medium such as liquid nitrogen is pumped into the probe, causing it to freeze at low temperatures; the probe is then used to kill tissue it contacts but not surrounding cells. The body heals by dissolving the dead tissue. Some scarring generally occurs, but it is not as severe as that caused by surgery using a knife. Between 1960 and 1965 cryosurgery progressed in several specialty medical applications from a novelty to a commonly used surgical technique.

A Delicate Operation

Dr. Irving S. Cooper, a neurologist at New York's Saint Barnabas Hospital, was a pioneer in using cryosurgery. An example was his treatment of nine-year-old Steve Schiavo, who suffered from dystonia, a crippling condition caused by a brain tumor and characterized by tremors, muscle deformities, and loss of muscle control. Schiavo could no longer walk, and his arms had constant tremors. When Cooper performed brain surgery on him, the patient had to stay awake for the procedure because the tumor was next to the speech center of the brain, and if cells in that area were damaged, the patient could be left mute. His head was placed in a frame that kept him from moving, and Cooper injected a local anesthesia before making a small opening in the boy's skull to expose the tumor. Using X rays. Cooper accurately positioned the cryosurgical probe, freezing the tumor to minus ten degrees Celcius. As Cooper watched the tremor improve, he made Schiavo talk to ensure that only the tumorous cells were being destroyed. If too many were frozen, Cooper had thirty seconds to thaw the area before the damage became irreversible. When he was sure he had isolated the tumor, he froze it to minus eighty degrees for three minutes. The operation was a success.

Cancer Treatment

Dr. William G. Cahan of Memorial Sloan-Kettering Cancer Center also used cryosurgery. He pointed out that the main advantage of the cryoprobe to him was that it reduced bleeding in the area of surgery. Cahan used cryosurgery to treat cancer of the uterine cervix painlessly and bloodlessly; the procedure was later found to be more effective in precancerous problems of the cervix. Cahan also reduced a large tongue cancer by cryosurgery, then removed the shrunken lesion using regular surgical techniques.

Less Blood

Loss. Dr. Leo Schwartz of Manhattan Eye, Ear and Throat Hospital used cryosurgery to re-move small tumors of the larynx that were not cancerous. Dr. Robert W. Rand used the method on the pituitary gland at the base of the brain, approaching the surgery site through the patient's nose. University' of Michigan doctors Walter Work and Mansfield F. W. Smith used cryosurgery to remove noncancerous blood-vessel tumors in the nose called angiofibromas that can cause massive nosebleeds. Traditional surgery of this type requires the transfusion of three to eight units of blood, on the average. These surgeons used cryosurgery to remove the tumors with no significant blood loss.