Retreatment rates were low with both aquablation and transurethral resection of the prostate.
Two-year data from the blinded, randomized WATER study showed similar durable outcomes between aquablation and transurethral resection of the prostate (TURP) as treatments for men with moderate-to-severe lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia. Retreatment rates were low for both arms of the study, said Neil Barber, BSc, MB, BS, during the 2020 European Association of Urology Virtual Congress.
At 2 years of follow-up, the mean International Prostate Symptom Score (IPSS) was similarly improved in men randomized to either aquablation or TURP. Men randomized to aquablation experienced a reduction in mean IPSS from 22.9 at baseline to 8.3 at 2 years (improvement of 14.6 points), and men randomized to TURP had a reduction from a mean of 22.0 at baseline to 7.0 (improvement of 15.0 points) at the 2-year follow-up (P = .7361 for difference).
“Aquablation of the prostate achieved exactly the same improvements in IPSS at 6 months and this is maintained out to 2 years. When one looks at the subanalysis of storage and voiding symptoms from the IPSS questionnaire, we see similar mirroring of improvement,” said Barber, consultant urologist, Weymouth Street Hospital, London, UK.
The global phase 3 WATER study randomized 184 men with moderate-to-severe LUTS related to BPH and a prostate volume of 30 to 80 mL to aquablation using the AquaBeam system (n = 117) or TURP (n = 67). Mean age at baseline was about 66 years, mean prostate volume was 54.1 mL in the aquablation arm and 51.8 mL in the TURP arm, and slightly more than half in each arm had a middle lobe.
Assessments included the IPSS, Male Sexual Health Questionnaire (MSHQ), International Index of Erectile Function (IIEF), and uroflow. WATER demonstrated that aquablation was noninferior to TURP on the primary efficacy study end point of reduction in IPSS at 6 months. In addition, aquablation proved superior (P = .0149) for the primary safety end points of incontinence, erectile dysfunction, ejaculatory dysfunction, and events requiring pharmacologic treatment, blood transfusion, or endoscopic, surgical, or radiologic intervention as assessed by the Clavien-Dindo classification. Of the patients who underwent aquablation and transurethral prostate resection, 26% and 42%, respectively, experienced a primary safety end point at 3 months.
In addition to improvement on the IPSS, 2-year improvements in maximum flow rate (Qmax) were similarly large in both groups: 11.1 cc/sec in the aquablation arm versus 8.7 cc/sec in the TURP arm (P = .1902). At 2 years, serum prostate-specific antigen level was reduced significantly in both groups, by 0.7 and 1.1 points, respectively (P = .3930), “suggesting equivalent prostate volume reduction using this surrogate marker,” said Barber. The 2-year retreatment rates were 4.3% for aquablation and 1.5% for TURP.
“Complication rates in terms Clavien-Dindo 2+ were equivalent between both groups, but there was an advantage overall in terms of complications for aquablation over TURP thanks to a lower risk of negative impact upon erectile dysfunction and dry ejaculation on the whole,” said Barber. Scores on the MSHQ were stable in the aquablation arm and decreased slightly in the TURP arm.
Another advantage to aquablation is that prostate size has little to no influence on the length of the procedure, he said.
Among the plethora of options for treatment of BPH, “I would offer [aquablation] to anybody you might offer a TURP or a laser to, who is particularly keen on reducing his risk of essentially dry ejaculation,” he said. “There are some caveats to that. I have stayed away from patients who are taking anticoagulants, and from my experience, that’s not an insignificant portion of patients. Beyond that, you could offer it to anybody. The real dilemma is there are potentially clear advantages in the very large prostate, once you mover over 80 or 100 mL, but it’s really that range of 50 to 80 mL where there are many options available in the guidelines, be it minimally invasive surgical treatments like UroLift and Rezum versus cavitating options including aquablation.”
Barber N, Gilling P, Bidair M, et al. Two-year outcomes after aquablation compared to TURP: Results from a blinded randomized trial. 2020 European Association of Urology Virtual Congress. July 17-26, 2020. Abstract 201.