Data showed a decrease in patient symptoms following Aquablation procedures, with an average IPSS of 22.6 at baseline compared with 6.8 at 5-year follow-up.
The WATER II trial (NCT03123250) assessing Aquablation therapy for lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) in men with large prostates successfully met its safety and efficacy performance goals, according to final 5-year results published in the Journal of Urology.1
The multicenter clinical trial enrolled 101 men with moderate to severe BPH symptoms and prostate volumes of 80 mL to 150 mL from September to December 2017. Patients were aged 45 to 80 years and were treated across 16 centers in the United States and Canada. Median prostate volume among all participants was 107 mL.
Data showed a decrease in patient symptoms following Aquablation procedures, with an average International Prostate Symptom Score (IPSS) of 22.6 at baseline compared with 6.8 at 5-year follow-up (change score = 15.9, P < .001). IPSS quality of life scores also decreased from an average of 4.6 at baseline to 1.3 at 5-year follow-up (change score = 3.3, P < .001).
Maximum urinary flow rate (Qmax) also showed improvement, increasing from an average Qmax of 8.6 mL/s at baseline to 17.1 mL/s at 5-year follow-up (change score = 9.2, P < .001). Post-void residual (PVR) urinary volume showed improvement as well, decreasing from an average of 141 mL at baseline to 64 mL at 5-year follow-up (P < .001).
In regard to retreatment, 3% of patients required surgical reintervention due to LUTS at an average of 25 months following the initial procedure. Further, 6% of patients were placed on BPH medications at an average of 34 months following the initial procedure.
In total, 96.3% of patients were free from a secondary BPH intervention at 5-year follow-up. No patients received surgical retreatment in year 4 or 5 of the study. The investigators also observed a 50% reduction among patients’ change in prostate-specific antigen (PSA) as a function of baseline PSA across the study period. There was no significant association observed between PSA change and the patients who received BPH medication or received surgical retreatment.
The investigators also conducted a prespecified subgroup analysis to compare IPSS, IPSS quality of life, Qmax, and PVR among patients with a prostate volume above and below 100 mL. The comparisons showed no significant efficacy differences between the 2 groups at 5 years.
Further research comparing Aquablation to enucleation in large prostates is currently underway in Europe for the prospective WATER III trial (NCT04801381).
The initial WATER trial (NCT02505919) enrolled 181 patients to prospectively compare the safety and efficacy of Aquablation and transurethral resection of the prostate (TURP).2
The primary efficacy end point was a reduction in IPSS at 6 months, and the primary safety end point were instances of Clavien-Dindo persistent grade 1, or 2 or higher operative complications.
At 6 months, Aquablation showed noninferior efficacy to TURP (P < .0001). In total, 42% of patients who underwent TURP experienced a safety event, compared with 26% among patients who underwent Aquablation (P = .0149). The authors indicated a more pronounced superior safety and efficacy benefit among patients with larger prostates, defined as 50 mL to 80 mL.
1. Bhojani N, Bidair M, Kramolowsky E, et al. Aquablation therapy in large prostate (80-150 mL) for lower urinary tract symptoms due to benign prostatic hyperplasia: final Water II 5-year clinical trial results. J Urol. Published online April 20, 2023. Accessed July 11, 2023. doi:10.1097/JU.0000000000003483
2. Gilling P, Barber N, Bidair M, et al. WATER: A double-blind, randomized, controlled trial of Aquablation vs transurethral resection of the prostate in benign prostatic hyperplasia. J Urol. 2018;199(5):1252-1261. doi:10.1016/j.juro.2017.12.065