WATER vs. WATER II three-year update: Comparing Aquablation therapy for benign prostatic hyperplasia in 30–80 cm3 and 80–150 cm3 prostates
Anis Assad1, David-Dan Nguyen2, Kevin Zorn1, Dean Elterman3, Naeem Bhojani1.
1Division of Urology, University of Montreal Hospital Centre (CHUM), Montreal, QC, Canada; 2Faculty of Medicine, McGill University, Montreal, QC, Canada; 3Division of Urology, Department of Surgery, University Health Network, University of Toronto, Toronto, ON, Canada
Some of the results of this abstract were presented at the AUA’s 2021 annual meeting* . *Medical and surgical retreatment rates will be presented for the first time.
Introduction: Surgical options are limited when treating large (>80 cc) prostates for lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH).[1][2] Aquablation therapy, a waterjet ablative procedure combining image guidance and robotics, is emerging as a safe and effective procedure with a short learning curve.[5][6][7][8] We aimed to compare the outcomes of Aquablation for small-to-moderate (30–80 cc) prostates with the outcomes for large (80–150 cc) prostates at 3-year followup.
Methods: WATER is a prospective, double-blind, multicenter, international clinical trial comparing the safety and efficacy of Aquablation and transurethral resection of the prostate (TURP) in the treatment of LUTS/BPH in men 45–80 years old with a prostate of 30–80 cc.[5][6] WATER II is a prospective, multicenter, single-arm, international clinical trial of Aquablation in men with a prostate of 80–150 cc.[7][8] We compare 36-month outcomes among 116 WATER and 101 WATER II study subjects undergoing Aquablation.[7][8][9] Students’ t-test or Wilcoxon tests were used for continuous variables and Fisher’s test for binary variables.
Results: International Prostate Symptom Score (IPSS) scores improved from 22.9 and 23.2 at baseline in WATER and WATER II, respectively, to 8.0 and 6.5 at 36 months, with 36-month reductions of 14.4 and 16.3 points, respectively (p=0.247). At baseline, urinary flow rate (Qmax) was 9.4 and 8.7 cc/sec in WATER and WATER II, improving to 20.6 and 18.5 cc/sec, respectively (p=0.552), at 36 months. Improvements in both IPSS and Qmax were immediate and sustained throughout followup. At three years, 98% and 94% of treated patients were BPH medication-free in WATER and WATER II, respectively (p=0.038). At three years, 96% and 97% of treated patients were free from surgical retreatment in WATER and WATER II, respectively (p=0.613).
Conclusions: Three-year followup demonstrates that Aquablation therapy leads to sustained outcomes, few irreversible complications, and low retreatment rates for the treatment of LUTS/BPH independently of prostate volume.
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