Aquablation is a robotic, water-based surgical procedure that removes enlarged prostate tissue causing urinary problems. It uses a high-pressure stream of salt water instead of heat to carve away the tissue blocking urine flow, guided in real time by ultrasound imaging. The procedure was FDA-cleared in 2017 and has become an option for men with benign prostatic hyperplasia (BPH) whose prostates range from about 30 to 150 grams.
How the Procedure Works
Aquablation operates in two distinct phases while you’re under general anesthesia. In the first phase, your surgeon uses a transrectal ultrasound probe to create a detailed map of your prostate, viewing it from multiple angles. On a console screen, the surgeon outlines exactly which tissue needs to be removed, setting the angle, depth, and contour of the planned resection. This mapping step is what distinguishes Aquablation from older techniques: the surgeon designs a precise surgical plan before any cutting begins.
In the second phase, a thin probe inserted through the urethra delivers a high-velocity jet of sterile saline at pressures between 500 and 8,000 PSI. The robot executes the mapped plan automatically, sweeping and rotating the jet to remove soft adenomatous tissue while the surgeon supervises and can pause or adjust at any point. Because the waterjet selectively cuts soft tissue and spares tougher collagen-based structures, the bladder neck, ejaculatory ducts, and urinary sphincter are largely preserved. No heat is generated during cutting, which eliminates the thermal damage to surrounding tissue that occurs with procedures like TURP (transurethral resection of the prostate) or laser-based treatments.
Who Is a Good Candidate
Aquablation was originally studied in prostates between 30 and 80 milliliters, but a second major trial (WATER II) expanded eligibility to prostates between 80 and 150 milliliters, with an average volume of 107 milliliters. This makes it one of the few minimally invasive options suitable for very large prostates, where traditional TURP becomes less practical.
You would generally not be a candidate if you have a history of prostate or bladder cancer, active urinary infection, urethral stricture, bladder neck contracture, significant bladder stones, or previous urinary tract surgery. A BMI above 42 was also an exclusion in the clinical trials. Your urologist will evaluate your specific anatomy and symptoms to determine if Aquablation is appropriate.
What to Expect on Procedure Day
The actual tissue-removal phase of Aquablation is notably fast. Because the robot executes a pre-mapped plan rather than requiring the surgeon to manually cut tissue in real time, operative times tend to be shorter than with TURP, particularly for larger prostates. You’ll be under general anesthesia throughout.
After the procedure, most people spend two to three hours in recovery. Some patients go home the same day once they’ve recovered from anesthesia. Others stay overnight in the hospital. A catheter is typically placed to drain urine while the prostate heals, though the exact duration varies by surgeon and how the procedure went.
Symptom Improvement
The primary measure of success in BPH treatment is how much urinary symptoms improve. In the landmark WATER trial, which followed patients for five years, men who had Aquablation saw their symptom scores drop by an average of 14.1 points on a standardized 35-point scale. That was significantly better than the 10.8-point improvement seen in the TURP group. This difference held steady across the full five years of follow-up, suggesting the results are durable rather than fading over time.
In practical terms, a 14-point improvement on that scale represents a dramatic change in daily life: less frequent urination, fewer nighttime trips to the bathroom, a stronger stream, and less of the urgency and incomplete emptying that define BPH symptoms.
Sexual Side Effects
This is where Aquablation distinguishes itself most clearly. Sexual side effects, particularly ejaculatory problems, are the most common complaint after traditional prostate surgery. Up to 66% of men who undergo TURP experience retrograde ejaculation, where semen flows backward into the bladder instead of out through the penis. Laser enucleation (HoLEP) has even higher rates, around 70% or more.
Aquablation performs substantially better. In the WATER trial, 90% of Aquablation patients preserved normal (antegrade) ejaculation at six months, compared to 64% of TURP patients. For men with prostates larger than 50 milliliters, the difference was even more striking: 98% preservation with Aquablation versus 59% with TURP. Across multiple studies, preservation rates for Aquablation ranged from 72% to as high as 99.6%, depending on prostate size and follow-up duration. The advantage over TURP persisted through five years of follow-up.
Erectile function remained essentially stable after Aquablation in all the major studies. The WATER trial reported no new cases of erectile dysfunction in either the Aquablation or TURP groups at two years. The WATER II trial, which treated larger prostates, also reported zero new erectile dysfunction cases at one year.
Why the Sexual Function Advantage Exists
The waterjet selectively destroys soft glandular tissue while preserving the collagen-rich structures that support ejaculatory function. Heat-based procedures like TURP and laser surgery can damage these structures through thermal spread. One nuance worth knowing: in some cases, surgeons use a brief cauterization step after Aquablation to control bleeding. When that post-treatment cautery was avoided in the WATER trial, ejaculation preservation rates climbed even higher (93% versus 84%), narrowing the gap with TURP. This suggests that some of the ejaculatory side effects attributed to Aquablation may actually come from the cautery step rather than the waterjet itself.
Risks and Complications
The most common short-term complication is bleeding, which can occur because the waterjet doesn’t cauterize tissue as it cuts. Some patients need a catheter for longer than expected or require a blood transfusion, though this is uncommon. Temporary urinary symptoms like urgency, frequency, or mild burning during urination are normal in the first few weeks as the prostate heals.
Serious complications like urinary incontinence or the need for repeat surgery are rare. The five-year WATER trial data showed symptom improvements holding steady, which suggests most patients don’t need a second procedure within that window.
How It Compares to Other BPH Treatments
TURP has been the standard surgical treatment for BPH for decades. Aquablation matches or exceeds it in symptom relief while causing significantly fewer sexual side effects. The trade-off is a somewhat higher risk of bleeding in the short term, since the waterjet doesn’t seal blood vessels the way electrical or laser energy does.
Compared to HoLEP, which is considered highly effective for large prostates, Aquablation showed less impact on ejaculatory function at three months in a head-to-head comparison. HoLEP may still be preferred in certain cases, particularly for extremely large prostates or when the surgeon has extensive HoLEP experience.
Compared to office-based procedures like UroLift or Rezūm, Aquablation removes more tissue and produces larger, more durable symptom improvements. Those less invasive options may still be appropriate for men with smaller prostates or milder symptoms who want to avoid general anesthesia altogether.