Aquablation Therapy in Large Prostates (80-150 mL) for Lower Urinary Tract Symptoms Due to Benign Prostatic Hyperplasia: Final WATER II 5-Year Clinical Trial Results

Purpose: We report 5-year safety and efficacy outcomes of the Aquablation procedure for the treatment of men with symptomatic benign prostatic hyperplasia and large-volume prostate glands. Materials and Methods: A total of 101 men with moderate to severe benign prostatic hyperplasia symptoms and prostate volumes between 80 and 150 mL underwent a robotic-assisted Aquablation procedure in a prospective multicenter international trial (NCT03123250). Herein we report the final 5-year results. Results: The study successfully met its safety and efficacy performance goal, which was based upon transurethral resection of the prostate outcomes typically done in smaller prostates, at 3 months. Mean prostate volume was 107 mL (range 80-150) at baseline. Patient symptoms showed a significant improvement where the mean (SD) International Prostate Symptom Score of 22.6 (6.4) at baseline to 6.8 (4.6) at 5 years, resulting in a change score of 15.9 (7.7, P < .001). Uroflowmetry measurements also demonstrated improvement where the mean maximum urinary flow rate increased from 8.6 (SD 3.4) to 17.1 (9.8) mL/s at 5 years, resulting in a change score of 9.2 (11.1) mL/s at 5 years (P < .001). A regression analysis evaluating change in PSA as a function of baseline PSA across all time points out to 5 years resulted in a 50% reduction. A prespecified subgroup analysis using a baseline prostate volume cutoff of 100 mL showed no difference in efficacy outcomes through 5 years. Freedom from a secondary benign prostatic hyperplasia procedure at 5 years was 96.3% based on Kaplan-Meier. Conclusions: At 5-years of prospective follow-up, the Aquablation procedure was shown to be safe with durable efficacy and low rates of retreatment in men with large prostates (80-150 mL).