Continuous saline bladder irrigation after blue light transurethral resection of bladder tumor increases recurrence-free survival in low- to intermediate-risk non-muscle invasive bladder cancer.

OBJECTIVES: To evaluate the efficacy of Continuous Saline Bladder Irrigation (CSBI) after blue light transurethral resection of bladder tumor (TURBT) to prevent recurrence of low- to intermediate-risk Non-Muscle Invasive Bladder Cancer (NMIBC). PATIENTS AND METHODS: We conducted a retrospective study including patients with low- to intermediate-risk NMIBC who underwent TURBT in two urological centers between January 2017 and December 2018. Each TURBT was performed using blue light after intravesical instillation of hexaminolaevulinic acid. The experimental group included patients who received CSBI while the control group included patients without CSBI. When practice, CSBI was started immediately after the surgery and was interrupted 24 hours thereafter. Low-risk NMIBC had a surveillance while intermediate NMIBC had 8 adjuvant endovesical instillations of Mitomycin. The primary endpoint was bladder tumor recurrence free-survival which was defined as the time between the initial TURBT and the date of TURBT for bladder recurrence. RESULTS: A total of 167 patients (median age: 71 years) were included: 20% female, 15% low-risk, 85% intermediate-risk NMIBC. CSBI was performed in 95 cases (57%). No complication related to irrigation was reported. Bladder recurrence was observed in 55 cases (32.9%): 22 (23.1%) in the CSBI group vs. 33 (45.8%) in the control group (P=0.002). Multivariate stepwise logistic regression analysis with backward selection revealed that CSBI (HR 0.47 [0.27-0.81]; P=0.006) and MMC (HR 0.55 [0.31-0.95]; P=0.034) were significantly associated with reduced risk of bladder recurrence. CONCLUSIONS: Continuous saline bladder irrigation reduced the risk of bladder recurrence after blue light TURBT in patients with low- to intermediate-risk NMIBC while being safe. Prospective randomized study is needed to confirm these results. LEVEL OF EVIDENCE: 3.