Aquablation versus TURP: 5-year outcomes of the WATER randomized clinical trial for prostate volumes 50-80 mL

Introduction: To report the 5-year efficacy and safety of Aquablation compared with transurethral resection of the prostate for the management of lower urinary tract symptoms secondary to benign prostatic hyperplasia in men with prostate volumes 50-80 mL. Materials and methods: In a large double-blinded, multicenter, and prospective randomized controlled trial, 96 randomized men with 50-80 mL prostates who underwent Aquablation or transurethral prostate resection were prospectively identified for subgroup analysis. Follow up was performed for up to 5 years. The primary efficacy endpoint was the reduction in International Prostate Symptom Score (IPSS) at 6 months. The primary safety endpoint was the occurrence of Clavien-Dindo (CD) postoperative complications grade 1 persistent and grade 2 or higher at 3 months. Results: Both groups had comparable baseline characteristics. Reduction in IPSS score was significantly higher in the Aquablation group across 5 years of follow up (-14.1 vs. -10.8, p = 0.02). The Aquablation group achieved a significantly lower rate of CD1P and CD2 or higher events at 3 months follow up (risk difference of -23.1%). Among recorded adverse events, de novo postoperative ejaculatory dysfunction was notably lower in Aquablation (risk difference of -21.9%), while the risk of bleeding remained similar after 6 months. The surgical and medical retreatment rate at 6 months was also lower in Aquablation (risk difference of -14.4%). Conclusions: In the 50-80 mL prostate volume subgroup, Aquablation yields superior long-term symptom relief and lower complication rates than standard transurethral resection, with notably lower rates of ejaculatory dysfunction. This further supports the adoption of Aquablation for men with medium-sized prostates.