AUA 2017: WATER Study Clinical Results – Phase III Double-blind Randomized Control Trial of Aquablation vs. Transurethral Resection of the Prostate for Moderate-to-Severe Benign Prostatic Hyperplasia

Boston, MA ( This late-breaking abstract was presented to report the results of the Phase III double-blind RCT of a comparison between the use of aquablation (or water stream to ablate/resect) for prostate resection and the standard-of-care transurethral resection of the prostate (TURP). Overall, 275 men with moderate to severe LUTS due to BPH were considered for enrollment in this study, titled WATER (Waterjet Ablation Therapy for Endoscopic Resection of prostate tissue). Patients with prior prostate surgery, prostate cancer, or neurogenic bladder were excluded. A total of 181 patients were included in the study, with 116 in the aquablation arm and 65 in the TURP arm.

Primary endpoints of the study were 3-month safety (defined as proportion difference in persistent Clavien grade 1 event or grade 2 or higher event by month 3) and 6-month efficacy (defined in IPSS at 6 months. Both were tested for non-inferiority. Aquablation was found to be superior in terms of primary safety, ejaculatory function postoperatively, incontinence severity; it was non-inferior in terms of primary efficacy, and it resulted in statistically significantly greater urine flow. Upon subgroup analysis of patients with >50g prostate size, aquablation was superior in regard to primary safety (Clavien complications: 19% Aquablation vs 43% TURP, p<0.01) and efficacy (IPSS drop: 17 points Aquablation vs 13 points TURP, p=0.01). Furthermore, the resection time for aquablation (4 minutes) was significantly shorter than TURP (27 minutes), and was independent of gland volume.

This promising technology may result in a substantially improved method for surgically treating patients with symptomatic BPH.

Authors: Claus Roerhborn, MD

Affiliation: Department of Urology, University of Texas Southwestern

Written By: Shoaib Safiullah, MS4 for

at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA