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April 8, 2002

Cyrosurgery becoming kidney cancer alternative

By Tia Webster


Emory urologists are using a new surgical technique—cryosurgery, or the application of extreme cold to kill cancerous tissue—in the treatment of kidney cancer.

The procedure was used at the Emory Clinic for the first time in October, but physicians predict that several more cryosurgical procedures will be performed there in the coming months. Cryosurgery shows promising results with minimal pain and bleeding, shorter recovery period and less expensive costs than traditional approaches, according to John Pattaras, assistant professor of urology.

“It is a kidney-sparing alternative method that is still investigational, but it spares the patient major surgery,” said Pattaras, director of the division of Minimally Invasive Urologic Surgery. “It is justified in older patients with small tumors and other medical problems. Moreover, older patients have less functioning kidney tissue and are at more risk for peri-operative complications.”

Younger patients with minimal medical problems would best benefit from a partial nephrectomy—removal of part of the kidney—Pattaras said. During the kidney ablation surgery, a laparoscope inserted through a quarter-inch incision into the abdomen lets the physician view the organs inside of the abdomen. The physician also uses an ultrasound device to locate the tumor and to help guide the cryoprobe.

The cryoprobe, containing liquid nitrogen, is inserted through a small 1/8-inch incision into the center of the tumor after a biopsy has been taken. Nitrous oxide then circulates through the instrument and causes the tip to drop to a temperature of approximately minus 90 to minus 100 degrees Celsius. The entire tumor is frozen, allowed to thaw, then frozen a second time. The freezing cycle is completed within 15–20 minutes, and the tumor is destroyed within the two hours of the entire procedure.

“The procedure freezes the cancer cells and directly kills them,” Pattaras said. “It also indirectly freezes the blood supply surrounding the tumor, thereby starving the tumor even if some cells survive. Kidney cells will not regenerate, so only scar tissue remains.”

Cryosurgery patients are admitted for overnight observation and discharged the next morning. Normally, patients with open surgery procedures are released in seven to 10 days.

Currently there are not outcome measures that compare the rate of survivorship or prevention of metastasis from cryosurgery to those of traditional procedures. Use of the procedure is too recent, and there is no five-year follow-up data, Pattaras said.

Cryosurgery traditionally has been used on external tumors, such as skin cancers and for retinoblastoma (childhood cancer of the retina). The American Cancer Society estimates in 2002 there will be 31,800 new cases of kidney cancers and 11,600 deaths. Kidney cancer is the eighth most common cancer in men and the 10th most common cancer in women.