BERKELEY, CA (UroToday.com) - Our study is one of many published in the recent urological literature addressing the increasing problem of sepsis following trans-rectal biopsy of the prostate. A number of different approaches to reducing this risk are being attempted, but the jury is still out on which method is best. Certainly, avoidance of prostate biopsy altogether is the only method to reduce the risk to zero, and a judicious approach to the elevated PSA in men is advised. Nonetheless, there will always remain a large group of men for whom prostate biopsy is required. The questions that arise are: the approach (trans-rectal or trans-perineal), the site preparation (rectal enema, iodine or alcohol solution, or none), the need to swab for resistant organisms, and most importantly the form of prophylaxis (which drug, how may doses, when to start and when to stop).
We attempted to target prophylaxis of ertapenem to a high-risk group of patients who were identified using a patient-administered questionnaire. Whilst we showed that ertapenem was an excellent form of prophylaxis in that it reduced the rate of sepsis to zero in our group, the risk stratification method was unsuccessful as a number of men who were identified as low-risk still suffered sepsis. We continue to question why this occurred. Whilst there was no formal audit of the accuracy of questionnaire completion, our anecdotal experience was that patient answers were largely correct. The conclusion, therefore, is that microbial resistance in our population is more complex than simply a number of well-recognised risk factors. It is possible, for example, that cross-contamination by individuals who associate with someone from a high-risk group may render them high-risk. Whatever the reason, a self-identification approach is insufficient and we no longer use nor recommend this.
At the 2014 American Urological Association Annual Meeting, held in Orlando, Florida, a number of approaches to risk reduction were presented. An emerging trend is studies examining the use of pre-biopsy rectal swab. An Asian study of 2 673 patients swabbed all men prior to biopsy for fluoroquinolone resistance but did not use this information to change the choice of prophylaxis. Whilst a high rate of 20% of men grew resistant organisms (likely due to the Asian nature of the cohort), the study showed a much greater rate of sepsis (4.4%) in this group compared with men not harbouring fluoroquinolone resistant organisms (0.9%). The findings were similar in other smaller studies also presented at the meeting. We are now collecting our own data on pre-biopsy antimicrobial resistance.
One of the inevitable questions that arise when prescribing increasingly broad-spectrum antibiotics is whether this will increase antimicrobial resistance. As clinicians, we have both a moral and scientific responsibility to safeguard our antibiotics and to use them appropriately. On the one hand, we do not wish to be heavy handed in our use of these agents, on the other, we do not wish to deprive patients of them if we know they will improve the safety and tolerability of a procedure. Given our own high-rates of fluoroquinolone resistance locally, and the outcome of our study, we now use ertapenem for all patients undergoing biopsy. However, such an approach is almost certainly not warranted in all population groups. Discussion with local microbiologists is essential and laboratory monitoring for a change in resistance patterns obligatory.
It remains unclear what the future holds for prostate biopsy. Our feeling is that screening for resistance by way of pre-biopsy swab is likely to be the way forward and, as indicated, we have started collecting data on this approach. For all clinicians who treat prostate cancer, a careful eye on the developments regarding post-biopsy sepsis is warranted.
Giovanni Losco, MB ChB(Dist), FRACS(Urol) as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Department of Neurourology, Royal National Orthopaedic Hospital, Stanmore and Department of Urology, University College Hospital, London