FDA Tells Doctors How To Avoid Rare Burns From Enlarged-Prostate Treatment
|October 20, 2000
WASHINGTON (AP) - A therapy that shrinks enlarged prostates by microwaving the gland can cause a rare but serious injury, occasionally burning men's tissue enough to require a colostomy or other surgery, the Food and Drug Administration warned doctors Friday.
Microwave therapy for enlarged prostates is a highly effective outpatient treatment to relieve urinary symptoms, and some doctors consider it safer than traditional prostate surgery. Some 25,000 men have undergone the treatment since the FDA approved the first prostate-heating machine in 1996.
But the FDA has learned of 16 men injured when the microwave temperatures got too high or microwaves beamed onto the wrong spot. In six cases, burns damaged the penis or urethra. Ten other men developed fistulas, abnormal channels that can form in such spots as the colon or urinary tract when tissue dies.
Some men required colostomies, partial penile amputation or other treatment, the FDA said in a warning e-mailed to health workers.
The warning shouldn't frighten men, cautioned David Daly of FDA's medical device surveillance office. The risk is very rare, and the FDA calls microwave therapy overall safe and effective, but it issued the warning so doctors can take fairly easy steps to prevent burns.
The prostate is a walnut-sized gland that surrounds the urethra, which carries urine to the penis. Prostates enlarge as men age, squeezing the urethra and making it difficult to urinate. More than half of all men over age 60 have the problem, called benign prostatic hyperplasia, or BPH - and 80 percent of men get it by age 80.
Surgery to trim the prostate is the most common and effective treatment, but it usually requires up to three days in the hospital and can cause such complications as impotence or incontinence. Some medications offer modest relief.
Microwave therapy is an hour-long outpatient procedure. Microwaves pulse through a catheter threaded through the urethra into the prostate, killing excess prostate tissue. Cooling water circulates inside the catheter so the urethra is not burned. A temperature sensor monitors that heat isn't too high.
The FDA warned doctors to:
-Tell patients to remain absolutely still during treatment and to complain about unusual pain. Don't oversedate men, so they can feel any problem.
-Remain with the patient through the entire procedure, to watch for slippage and pause treatment if he complains about pain. Don't treat patients whose prostates are the wrong size for microwaves or who have had prior pelvic radiation.