Emory urologists are using a new surgical techniquecryosurgery,
or the application of extreme cold to kill cancerous tissuein
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 nephrectomyremoval of part of the kidneyPattaras
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 1520 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.