Predictors of Infectious Complications after Targeted Prophylaxis for Prostate Needle Biopsy

Purpose: The incidence of infectious complications after transrectal ultrasound guided prostate needle biopsy is rising. We sought to identify the incidence and predictors of infection in a large cohort of men undergoing biopsy who receive targeted prophylaxis.

Materials and methods: We retrospectively reviewed the records of 5,214 consecutive patients who underwent transrectal ultrasound guided prostate needle biopsy from January 2013 to December 2014 at UroPartners, a large urology group comprising 28 clinics in metropolitan Chicago. At 1 microbiology laboratory all swabs were processed, the presence of fluoroquinolone resistant gram-negative rods was identified and sensitivity tests were performed. Prophylaxis for biopsy was guided by rectal swab culture. Characteristics of patients with and without infectious complications were compared using the Kruskal-Wallis and chi-square tests. Multivariable logistic regression was done to determine predictors of infectious complications. Analyses were performed with R, version 2.14.2 (https://www.r-project.org/).

Results: Of the 5,214 biopsies performed 56 infectious (1.1%) and 24 sepsis complications (0.46%) were found. On univariable analysis nonCaucasian race and fluoroquinolone resistant microbes were predictors of infection (p <0.05). On multivariable analysis fluoroquinolone resistant rectal vault flora (OR 9.98, 95% CI 3.79-26.3) and the number of biopsy cores taken (OR 1.28 per core, 95% CI 1.04-1.54) were independent predictors of infection.

Conclusions: Despite targeted prophylaxis patients with fluoroquinolone resistant rectal vault flora have higher odds of infectious complications following transrectal ultrasound guided prostate needle biopsy. In these patients one should consider using other biopsy approaches or techniques to minimize risk.