Incomplete bladder emptying and urinary tract infections after botulinum toxin injection for overactive bladder: Multi-institutional collaboration from the SUFU research network

Introduction: Onabotulinumtoxin A (BTX-A) is an effective therapy for overactive bladder (OAB), however, adverse events may prevent patients from initiating therapy. The study objective was to report real-world rates of incomplete emptying and urinary tract infection (UTI) in men and women undergoing BTX-A for OAB.

Methods: Eleven clinical sites performed a retrospective study of adults undergoing first-time BTX-A injection (100 units) for idiopathic OAB in 2016. Exclusions included: postvoid residual (PVR) > 150 ml, prior BTX-A, pelvic radiation, or need for preprocedure catheterization. Primary outcomes at 6 months were incomplete emptying (clean intermittent catheterization [CIC] or PVR ≥ 300 ml without the need for CIC); and UTI (symptoms with either positive culture or urinalysis or empiric treatment). We compared rates of incomplete emptying and UTI within and between sexes, using univariate and multivariable models.

Results: 278 patients (48 men and 230 women) met inclusion criteria. Mean age was 65.5 years (range: 24-95). 35% of men and 17% of women had incomplete emptying. Men had 2.4 (95% CI: 1.04-5.49) higher odds of incomplete emptying than women. 17% of men and 23.5% of women had ≥1 UTI, the majority of which occurred within the first month following injection. The strongest predictor of UTI was a history of prior UTI (OR: 4.2 [95% CI: 1.7-10.3]).

Conclusions: In this multicenter retrospective study, rates of incomplete emptying and UTI were higher than many previously published studies. Men were at particular risk for incomplete emptying. Prior UTI was the primary risk factor for postprocedure UTI.