Pre-prostate biopsy prophylaxis lacks efficacy in interim analysis

August 1, 2011

Decontamination of the rectum with povidone-iodine prior to transrectal ultrasound (TRUS)-guided prostate biopsy does not yet appear to be efficacious in reducing infection rates.

Key Points

Vienna, Austria-Decontamination of the rectum with povidone-iodine prior to transrectal ultrasound (TRUS)-guided prostate biopsy does not yet appear to be efficacious in reducing infection rates, according to an interim report on the first 500 patients of an expected 1,044 patients in an ongoing study being conducted at the Vancouver Prostate Centre, Vancouver, BC.

It is estimated that one million prostate biopsies are done every year in North America. About 3% to 11% of patients develop infectious complications, out of which 0.1% to 5% have sepsis, researchers say.

"We would like to reduce these infections with a simple and cheap antiseptic solution," said first author Zeid Musa AbuGhosh, MD, assistant professor of urology at Hashemite University, Zarqa, Jordan. "We tested the efficacy and safety of povidone-iodine in reducing the rate of postoperative biopsy infections."

After the biopsy, patients went home and measured their temperature for 48 hours, at which time they also supplied material for urine culture. Interviews were conducted at 1 week post-biopsy, looking for fever or other symptoms of infection as well as other complications of the biopsy.

Treatment yields no difference

Infectious complications developed in 19 of 500 patients overall (3.8%), including eight of 258 treated patients (3.1%) and 11 of 242 controls (4.5%). There was no statistical difference between the two groups (p>.05). There was no significant adverse reaction to the povidone-iodine used.

The sepsis rate was 0.6%, or one of 258 treated patients (0.4%) and two of 242 of controls (0.8%). Again, there was no statistical difference between the two groups.

Rectal swab cultures yielded ciprofloxacin [Cipro, Proquin XR]-resistant bacteria in 21% of cases, out of which 88.5% were Escherichia coli. All three patients with sepsis had ciprofloxacin-resistant E. coli in the rectal swab and post-biopsy urine.

"A lot of patients have Cipro-resistant bacteria in their rectum, but they do not develop an infection," said senior author Peter C. Black, MD, assistant professor of urologic sciences at the University of British Columbia, Vancouver. "However, virtually all infections are caused by Cipro-resistant bacteria. We have determined which antibiotics would be appropriate for empiric treatment of patients with post-biopsy infection. The resistant bacteria were especially sensitive to imipenem (100%), ticarcillin/clavulanate (99%), and piperacillin/tazobactam (97%)."