Antimicrobial prophylaxis does not prevent UTI after transurethral resection of bladder tumour

Use of antimicrobial prophylaxis (AMP) appears to have no protective benefit against postoperative urinary tract infections (UTIs) or asymptomatic bacteriuria (ABU) in patients undergoing transurethral resection of bladder tumours (TURB), a recent study has shown.

“Our findings may inform harmonization of international guidelines,” the researchers said.

A systematic search was carried out in Embase, Medline, and the Cochrane Central Register of Controlled Trials for randomized and nonrandomized controlled trials assessing the effect of AMP in patients with TURB on postoperative UTIs or ABU.

The researchers assessed risk of bias using RoB 2.0 or the Newcastle-Ottawa Scale and conducted fixed and random effects meta-analyses. In addition, they searched Medline exploratorily for risk factors for UTI after TURB as a potential basis for a scoping review.

A total of 986 publications were screened, of which seven studies with 1,735 participants were included. The reported effect sizes varied significantly. [J Urol 2021;205:987-998]

AMP had no significant impact on UTIs (pooled odds ratio [OR] of the random effects model, 1.55, 95 percent confidence interval [CI], 0.73–3.31). In random effects meta-analysis examining the effect of AMP on ABU, the OR was 0.43 (95 percent CI, 0.18–1.04).

“Analysing the secondary outcome, we also found no statistically significant evidence for a reduction of ABU in our random effects model,” the researchers said. “However, both the OR of the random effects model and the statistically significant results from the fixed effects model indicate a potential reduction of ABU after AMP.”

Nonetheless, even if the results indicated that AMP might reduce postoperative ABU, these would not be relevant since ABU does not cause UTI and would thus not require further treatment, according to the researchers.

Additionally, risk of bias was deemed moderate. Three studies were identified in the exploratory search, which reported age, preoperative pelvic radiation, preoperative hospital stay, duration of operation, tumour size, preoperative ABU, and pyuria as risk factors for UTIs following TURB.

“To better account for the influence of risk factors in specific patient groups that may benefit from AMP, a well-designed prospective study is recommended,” the researchers said. “Such knowledge could help limit the use of AMP in TURB and potentially target AMP in TURB to a high-risk population only.”

Current international guidelines have significant discrepancies on the use of AMP in TURB. [Int Urol Nephrol 2018;50:1923-1937]

Such differences in recommendations could be explained by previous studies and systematic reviews on AMP that did not clearly differentiate between different endourological interventions in general or between transurethral resection of the prostate and TURB in particular. [Jpn J Infect Dis 2009;62:440-443; J Urol 2015;193:543-547]

“Since this systematic review has been published, new studies have been carried out on the subject, which we could include in our meta-analysis,” the researchers said. “We were not able to demonstrate that AMP has a significant effect on postoperative UTI or ABU in TURB.”