Aquablation results last at least five years based on current clinical trial data, with 95% to 97% of patients avoiding a second surgical procedure during that period. Symptom scores drop sharply within the first month and hold steady through five years of follow-up, making the procedure one of the more durable minimally invasive options for an enlarged prostate.
Five-Year Symptom Relief
The two landmark clinical trials tracking aquablation patients, known as WATER and WATER II, followed men for five years after their procedures. Both trials showed substantial and sustained improvement. Symptom scores (measured on a standardized 35-point scale) dropped from around 23 points at baseline to about 7 points at five years, a reduction of roughly 16 points. That level of improvement appeared within the first few months and remained essentially flat through every year of follow-up.
Urinary flow rate, which measures how quickly urine leaves the bladder, improved by about 125% from baseline and held at that level through the five-year mark. Most of that improvement appeared within the first month after surgery.
How Often Patients Need Retreatment
Retreatment rates are the clearest measure of how long a procedure truly lasts. In the WATER trial, which studied prostates in the 30 to 80 mL range, 95% of patients were free from any additional surgical procedure at five years. In WATER II, which focused on larger prostates (80 to 150 mL), that number was similar at 96.3%. No patients in the larger-prostate group needed a second surgery in years four or five, suggesting results stabilize over time rather than fade.
A systematic review of retreatment rates across minimally invasive prostate therapies found that aquablation had no retreatments in the first year, with rates reaching 4.4% to 6% by the five-year mark. The few patients who did need retreatment in the WATER II trial required it at an average of 25 months after their initial procedure.
Medication use stayed low as well. At five years, 99% of patients in the WATER trial and 94% in WATER II remained free of any prostate medication. Among those who did restart medication, it happened around 34 months after the procedure on average.
How Aquablation Compares to TURP
TURP (transurethral resection of the prostate) has long been the standard surgical treatment for an enlarged prostate. In the randomized WATER trial, which directly compared the two, aquablation produced a 15.1-point symptom improvement at five years compared to 13.2 points for TURP. That difference wasn’t statistically significant overall, meaning the two procedures performed similarly for average-sized prostates.
The gap widened for men with larger prostates (50 mL or above). In that group, aquablation produced 3.5 more points of symptom improvement across all follow-up visits compared to TURP, a statistically significant difference. Men who had aquablation were also 51% less likely to need any secondary therapy, whether medication or another surgery, over the five-year period. For larger prostates especially, aquablation appears to hold up better over time.
Sexual Function After the Procedure
One of the main reasons men choose aquablation over TURP is the lower risk of sexual side effects, particularly retrograde ejaculation (where semen goes into the bladder instead of out through the penis). In the WATER trial, 90% of aquablation patients maintained normal ejaculation at six months, compared to 64% of TURP patients.
Preservation rates across multiple studies range from 72% to as high as 99.6%, depending on prostate size and how the measurement was done. Men with larger prostates tend to have somewhat lower preservation rates, around 81%, which makes sense given the larger amount of tissue removed. One of the largest studies, following 330 patients for four years, reported a preservation rate of 99.6%, though that figure is likely on the optimistic end. Erectile function is generally unaffected by the procedure.
What Prostate Size Means for Durability
Aquablation is one of the few minimally invasive procedures approved for very large prostates, up to 150 mL. The WATER II trial specifically studied prostates in the 80 to 150 mL range and found durable results at five years: a 16-point drop in symptom scores, a 9.2 mL/s increase in urinary flow rate, and significant quality-of-life improvements. Only 6% of patients needed to restart prostate medication, and only 3% required a second surgery.
This matters because large prostates have historically been harder to treat with minimally invasive techniques. Many other procedures are either not indicated for prostates above 80 mL or show higher retreatment rates at that size. For men in this category, the five-year data suggests aquablation holds up well, with the caveat that clinical trial data beyond five years is not yet available. The procedure is still relatively new, with FDA clearance granted in 2017, so longer-term data will take more time to accumulate.