Continuous bladder irrigation after transurethral resection of non-muscle invasive bladder cancer for prevention of tumour recurrence: a systematic review

Background: Non-muscle invasive bladder cancer (NMIBC) can recur despite transurethral resection of bladder tumour (TURBT) that clears macroscopic disease, partly from re-implantation of exfoliated cells. Immediate instillation of intravesical chemotherapy (IC) can reduce recurrence, is guideline-recommended but is under-utilized. Continuous bladder irrigation (CBI) immediately post-TURBT is postulated to prevent re-implantation, and may provide a simple, cheap and practical alternative. We undertook a systematic review to assess the effect of CBI on NMIBC recurrence. Methods: Following PRISMA guidelines, relevant publications were identified by online search of databases, including Ovid Medline and EMBASE (1980-2019). All published prospective randomized controlled trials comparing CBI post-TURBT to a control group were included. The primary end-point was recurrence. Results: Our search yielded 514 studies, of which six met inclusion criteria. Two studies (935 participants), albeit without peer-reviewed publication, comparing CBI to no CBI both showed a reduction in recurrence at 2 years. Four publications from three trials (331 participants) compared CBI to IC, showing similar recurrence rates at 1 year (odds ratio 1.29, 95% confidence interval 0.78-2.13) but a lower risk of adverse events (6-34% versus 27-48%). Conclusion: CBI post-TURBT appears to yield 1-year recurrence rates of NMIBC comparable to immediate IC. However, existing studies are small and of heterogenous design, precluding definitive conclusions. Further trials are required to determine if CBI can be implemented routinely to reduce NMIBC recurrence, as well as the optimal irrigant, volume and duration.