Study questions use of pre-op cultures to prevent prosthetic infection

Prior to artificial urinary sphincter and inflatable penile prosthesis placement, it is generally recommended to take a preoperative negative urine culture and treat UTI in order to prevent device infection. However, according to Nicholas Kavoussi, MD, of the University of Texas Southwestern in Dallas, medical literature lacks evidence to support this practice. In this interview from the AUA annual meeting in San Diego, Dr. Kavoussi sits down with Arthur L. Burnett, II, MD, MBA, of the Urology Times Editorial Council to discuss his group’s research that raises questions about the utility of preoperative urine cultures in predicting or preventing prosthetic device infection.

Dr. Burnett: We’re highlighting Dr. Kavoussi’s presentation at the AUA annual meeting, which was presented very nicely and generated a great deal of discussion. Tell us about the poster you presented and what prompted you to do this study.

Dr. Kavoussi: The presentation was on the utility of preoperative urine cultures in prosthetic urologic device implantation. We live in an era of antimicrobial stewardship. Routine bacteria screening leads to increased bacterial resistance, side effects of medications, cost of medications, and delay of care for patients, and that ultimately drove us to the study.

Dr. Burnett: What were your basic findings, and were you surprised by your findings?

Dr. Kavoussi: Two main things came out of this article. The first is that we found that the majority of men getting artificial urinary sphincters alone, compared to those getting penile prosthetics, have higher rates of preoperative urine cultures. In our multivariate analysis, ultimately we saw that pretty much all the factors that confound for positive urine cultures dropped off, implicating the loss of the sphincteric mechanism as one of the primary reasons these men developed bacteria with ascension of bacteria of the urinary tract. The second finding, which was predominantly what we looked at, was that regardless of preoperative urine culture, the rate of infections of these devices did not change. There was no statistical significance between the infectious rates, which was our biggest finding.

Dr. Burnett: That is very interesting. Just to make sure I’m clear, are you saying that the same rates of device infections occurred irrespective of a positive or a negative preoperative urine culture?

Dr. Kavoussi: Exactly.

Dr. Burnett: That actually is very interesting to observe because common practice has been to check for a urinary tract infection and that may impact how we go forward with treating or preventing risk of infection with a prosthetic.

Dr. Kavoussi: Of course. One of the things I need to clarify is that we looked for bacteria, and in patients that had active infections and any patients with active symptoms, we did not implant a prosthetic. The second thing to mention is that there are no standard guidelines on how to approach these patients. So even though it’s common practice and usually advised, there’s little data to sort of support preoperative screening or lack of screening in these patients.

Dr. Burnett: So should we think to change how we go about our practice with this observation?

Dr. Kavoussi: The limitation is, obviously, that this study is retrospective. This is data from a single institution and it’s a very high-volume center. Keeping those items in mind, I think there’s a selection of patients who have preoperative urine cultures done who may be good candidates-are at low risk for infection-and I think maybe you could screen with just urinalysis. There may be other things you can do rather than go through an entire urine culture workup and expose them to the potential of needing a preoperative antibiotic. In this select groups of patients, I think you can probably extrapolate this to patients in high-volume institutions.

Dr. Burnett: Certainly, we would need more studies of this sort and might consider this a hypothesis-driven observation at this point. But we should continue to make this sort of investigation, maybe with a prospective study. Would that be something you would consider?

Dr. Kavoussi: I think so. I think the next step would be a prospective study.