By Mr Neil Haldar, Consultant Urological Surgeon
Medically reviewed: 17 October 2026
Aquablation is a robot-assisted surgical treatment for an enlarged prostate (BPH) that uses a high-pressure waterjet to remove obstructing prostate tissue. It provides substantial, lasting relief from urinary symptoms while offering a better chance of preserving normal ejaculation than traditional TURP or laser enucleation surgery.
Clinical studies show good results for prostates measuring 30–150 mL, with emerging evidence in larger glands. However, Aquablation is not necessarily the best option for everyone. Treatments such as HoLEP may provide more complete relief of urinary obstruction, particularly in men with large prostates.
This guide explains how Aquablation works, what the latest clinical evidence shows, its risks and benefits, and how it compares with other prostate treatments.
What is Aquablation and how does it work?
Aquablation treats benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate that can compress the urethra and obstruct the flow of urine.
Common symptoms include a weak stream, difficulty starting urination, frequent or urgent urination, waking at night to pass urine and incomplete bladder emptying.
Surgery may be appropriate when symptoms remain troublesome despite medication, medication causes unwanted side effects, or complications such as urinary retention, recurrent infections, or bladder stones develop.
Aquablation removes the obstructing tissue through the urethra without external incisions.
The operation involves four stages:
- Ultrasound mapping. An ultrasound probe in the rectum and a camera in the urethra provide detailed images of the prostate.
- Treatment planning. The surgeon identifies which tissue needs removing and plans around important structures involved in continence and ejaculation.
- Robotic waterjet removal. A robot directs a high-pressure saline jet through the planned treatment area. The tissue-removal stage usually takes only a few minutes.
- Bleeding control. The surgeon controls bleeding using targeted cautery, catheter balloon pressure or both.
The waterjet does not use heat to remove tissue, although cautery may be used afterwards to control bleeding.
The surgeon remains responsible for planning, supervising and completing the operation. Aquablation is therefore robot-assisted rather than autonomous surgery.
How effective is Aquablation?
Aquablation produces substantial improvements in urinary symptoms and flow, with benefits demonstrated for at least five years.
The strongest evidence comes from the WATER and WATER II studies, together with more recent comparisons against laser enucleation.
| Study | Prostate size | Main findings |
|---|---|---|
| WATER | 30–80 mL | Randomised comparison with TURP; similar sustained symptom relief at five years, with less ejaculatory dysfunction |
| WATER II | 80–150 mL | IPSS improved from 22.6 to 6.8 at five years; approximately 96% free from further BPH surgery |
| WATER III | 80–180 mL | Similar short-term symptom improvement to laser enucleation, with better ejaculation preservation |
| 2026 meta-analysis | Various sizes | Similar overall patient-reported symptom scores, but laser enucleation achieved better urinary flow and bladder emptying |
The International Prostate Symptom Score (IPSS) measures urinary symptoms from 0 to 35, with higher scores indicating more severe problems.
In WATER II, maximum urinary flow improved from approximately 8.6 to 17.1 mL/second at five years.
Across the WATER and WATER II studies, approximately 94–97% of men remained free from further BPH surgery at five years, depending on the study and analysis.
These outcomes are encouraging, although some patients required medication again. The studies were also supported by Aquablation’s manufacturer, and long-term comparisons against HoLEP remain limited.
Aquablation versus HoLEP: which is better?
Aquablation generally offers better preservation of ejaculation, while HoLEP and other laser enucleation techniques produce more complete objective relief of urinary obstruction.
This distinction matters when choosing treatment.
The WATER III study, published in 2026, compared Aquablation with laser enucleation (HoLEP or thulium laser enucleation) in men with large prostates.
At three months, average improvements in urinary symptom scores were similar. However, reported retrograde ejaculation was substantially less frequent after Aquablation:
- Aquablation: approximately 15%
- Laser enucleation: approximately 77%
The study was partially randomised, and its principal published results were short-term, so these findings require longer follow-up.
A September 2026 systematic review and meta-analysis of direct comparative studies provided further insight.
It found:
- No statistically significant difference in overall patient-reported urinary symptom scores.
- Maximum urinary flow was approximately 5.7 mL/second higher following laser enucleation.
- Post-void residual urine approximately 12 mL lower following laser enucleation.
- Significantly less ejaculatory dysfunction following Aquablation.
The review also identified higher early readmission and catheter reinsertion rates after Aquablation in a separate administrative claims dataset. These observational findings need cautious interpretation.
The practical implication is that similar symptom scores do not necessarily mean equally complete relief of obstruction.
For a man who strongly values preserving ejaculation, Aquablation may be particularly attractive. For someone with severe obstruction, a very large prostate or a priority for maximum improvement in flow and emptying, HoLEP may be preferable.
Direct comparative evidence remains limited, and a treatment decision should not rest on these figures alone.
Does Aquablation preserve ejaculation and erections?
Preserving normal ejaculation is one of Aquablation’s principal advantages.
After conventional TURP or HoLEP, semen commonly passes backwards into the bladder rather than out through the penis. This is known as retrograde ejaculation.
It is generally harmless but can affect fertility and may be unwelcome.
Aquablation allows the surgeon to plan tissue removal around structures involved in ejaculation.
In the randomised WATER trial, procedure-related ejaculatory dysfunction occurred in 7% of Aquablation patients compared with 25% following TURP.
Most men retain the ability to ejaculate after Aquablation, but preservation is not guaranteed. Results vary with prostate anatomy, surgical technique and pre-existing function.
Clinical trials have generally shown no significant average deterioration in erectile function. However, individual changes are possible.
Most men can still experience orgasm following surgery, although semen production and orgasmic sensation may change.
If maintaining ejaculation or fertility is particularly important, discuss this explicitly with your surgeon before treatment.
What are the risks of Aquablation?
Aquablation is generally well tolerated, but it carries the risks associated with prostate surgery.
Bleeding
Bleeding has historically been the main concern because the waterjet removes tissue without sealing blood vessels.
Early clinical studies reported relatively high blood transfusion rates, particularly in larger prostates.
Modern bleeding-control techniques have substantially improved outcomes.
A large real-world analysis reported a decline in recorded transfusion rates from 2.3% in 2019 to approximately 0.1% in 2023–24.
However, these figures were partly based on adverse-event reporting systems that may under-report complications. The latest figure should not be regarded as a guaranteed individual risk.
Significant bleeding, clot retention, transfusion or a return to theatre remain possible.
Other complications
Possible complications include:
- Blood in the urine during recovery
- Urinary tract infection
- Temporary urgency, frequency or burning
- Difficulty passing urine after catheter removal
- Temporary urinary leakage
- Urethral stricture or bladder neck narrowing
- Changes in ejaculation or sexual function
- Persistent urinary symptoms despite surgery
- Recurrence of obstruction requiring further treatment
Persistent stress urinary incontinence is uncommon, although temporary urgency or leakage may occur.
Important limitations
Blood thinners: Patients taking anticoagulants or antiplatelet medication require individual assessment. Some may be better suited to another treatment. Never stop prescribed medication without medical advice.
Prostate cancer: Aquablation is not an investigation for prostate cancer. Some tissue may be available for histology, but it generally provides less diagnostic material than TURP or HoLEP. Cancer concerns should be assessed before surgery.
Very large prostates: Aquablation has been used in glands larger than 150 mL, but long-term evidence is less extensive than for established enucleation techniques.
Bladder dysfunction: If the bladder muscle is weak or overactive, removing the obstruction may not resolve every urinary symptom.
How does Aquablation compare with other enlarged prostate treatments?
No single treatment is best for everyone.
| Treatment | Main advantage | Main limitation |
|---|---|---|
| Aquablation | Durable symptom relief with favourable ejaculation preservation | Bleeding risk; shorter comparative follow-up |
| TURP | Established, effective treatment | Ejaculatory dysfunction is common |
| HoLEP | Excellent durable deobstruction, including large prostates | Ejaculatory dysfunction is common |
| GreenLight laser | Effective vaporisation with good bleeding control | Suitability and durability depend on prostate size and technique |
| Rezūm | Minimally invasive, generally favourable sexual-function preservation | Slower improvement; further treatment may be required |
| UroLift | Often rapid recovery with ejaculation preservation | Anatomical restrictions and higher retreatment rates |
| Prostate artery embolisation (PAE) | Avoids a transurethral operation | Less predictable objective relief of obstruction |
Aquablation is particularly worth considering for men who want substantial, durable symptom relief but place significant value on maintaining ejaculation.
Men who prioritise maximum relief of obstruction or have very large prostates may prefer HoLEP. Those seeking a less invasive procedure may consider Rezūm, UroLift or PAE, provided their anatomy and clinical circumstances are suitable.
Who is suitable for Aquablation?
Aquablation may be appropriate if you:
- Have bothersome urinary symptoms caused by prostate enlargement
- Have not obtained satisfactory relief from medication
- Prefer surgery rather than long-term tablets
- Have a prostate measuring approximately 30–150 mL
- Have an obstructing middle lobe
- Wish to preserve normal ejaculation
- Have urinary retention caused by prostate obstruction
It may be less suitable if you have significant bladder muscle weakness, an exceptionally large or small prostate, certain bleeding risks or complex anatomy following previous treatment.
Men with urinary retention can often undergo Aquablation successfully, but the likelihood of becoming catheter-free depends partly on bladder function.
What tests are needed?
Assessment commonly includes a urinary symptom questionnaire, urine flow test, bladder scan, and prostate size measurement.
A bladder diary, PSA blood test, prostate MRI, cystoscopy or urodynamic studies may also be appropriate, depending on the clinical findings.
The aim is to establish whether prostate obstruction is responsible for your symptoms and which treatment offers the best balance of benefit and risk.
What is recovery like after Aquablation?
Most men stay in hospital for approximately one night and require a urinary catheter for one to three days. Recovery varies with prostate size, bleeding, bladder function and individual circumstances.
The operation is performed under general or spinal anaesthesia. A catheter is left in place afterwards, often with saline irrigation to prevent blood clots from forming.
Once bleeding has settled and you can pass urine satisfactorily, you can usually go home.
Recovery timeline
| Period | What to expect |
|---|---|
| First 1–3 days | Catheterisation, sometimes bladder irrigation; most patients discharged after approximately one night |
| First 1–2 weeks | Burning, urgency, frequency and intermittent blood in the urine; many return to light or desk-based work |
| Weeks 2–4 | Progressive improvement; some intermittent bleeding may continue |
| Weeks 4–6 | Gradual return to heavy exercise, lifting and cycling with surgical approval |
| Around 3 months | Most men have achieved substantial symptom improvement; follow-up assessment |
You can resume driving when you feel comfortable, are no longer affected by sedating medication, and can perform an emergency stop safely. Sexual activity can often resume after approximately two to four weeks, according to your surgeon’s advice.
Temporary blood staining and urinary irritation are common. However, seek urgent medical advice if you cannot pass urine, develop a fever, experience heavy bleeding or pass large clots.
Some patients notice an improved stream immediately after catheter removal, while urgency and frequency may take several weeks or longer to settle.
What do NICE and European guidelines recommend?
UK and European clinical guidance recognises aquablation.
NICE HealthTech guidance HTG691, previously IPG770, permits transurethral waterjet ablation under standard arrangements for clinical governance, consent and audit. The change in guidance number did not alter NICE’s recommendations.
The 2026 European Association of Urology (EAU) guidelines give a strong recommendation for Aquablation as an alternative to TURP for men with moderate-to-severe symptoms and prostate volumes of 30–80 mL, particularly when preserving ejaculation is important.
The EAU also recognises encouraging five-year evidence in glands measuring 80–150 mL, while emphasising the need for further comparative trials in larger prostates.
Frequently asked questions about Aquablation
Is Aquablation better than TURP?
Both provide substantial relief from urinary obstruction. In the WATER trial, five-year symptom improvements were broadly comparable, while Aquablation caused significantly less procedure-related ejaculatory dysfunction.
Is Aquablation better than HoLEP?
Neither is universally better. Aquablation offers better ejaculation preservation, while HoLEP provides more complete objective relief of obstruction and has longer-term durability evidence.
How long do Aquablation results last?
Five-year studies show sustained symptom improvement, with approximately 94–97% of patients free from another BPH operation. Longer-term comparative evidence is still developing.
Can Aquablation treat a large prostate?
Yes. Good five-year outcomes have been demonstrated in prostates up to 150 mL, with emerging evidence in larger glands. HoLEP remains an established alternative for very large prostates.
Will Aquablation affect my sex life?
Most men retain erections and ejaculation, although changes can occur. Aquablation offers a better chance of preserving ejaculation than conventional TURP or HoLEP, but individual outcomes cannot be guaranteed.
Can I have Aquablation if I already have a catheter?
Often, yes. Men with urinary retention may become catheter-free after surgery, although success depends partly on bladder muscle function.
Is Aquablation available on the NHS or privately?
Aquablation is available at selected NHS and private hospitals in the UK. Availability and private insurance coverage vary, so confirm local provision and insurer authorisation.
Is Aquablation the right treatment for you?
Aquablation is an effective surgical option for benign prostate enlargement, combining substantial symptom relief with a favourable chance of preserving ejaculation.
However, its advantages must be balanced against bleeding risk, the degree of obstruction, prostate size and the longer clinical experience available with treatments such as HoLEP.
The most appropriate operation depends on your anatomy, bladder function, general health and what matters most to you — whether that is improving urinary flow, avoiding future treatment, recovering quickly or preserving sexual function.
A specialist urological assessment can help determine which options are suitable.
About the author
Mr Neil Haldar — Consultant Urological Surgeon
Mr Neil Haldar has been a Consultant Urological Surgeon since 2005. His practice includes the assessment and treatment of benign prostate enlargement, urinary symptoms, urinary retention and prostate cancer.
He has extensive experience in general urology and minimally invasive urological surgery, including robotic and laparoscopic procedures.
He consults privately in Buckinghamshire and surrounding areas, including at The Chiltern Hospital, The Shelburne Hospital and The Clementine Churchill Hospital.
Book a consultation
Your assessment will establish the likely cause of your urinary symptoms and help identify the treatment best suited to your prostate anatomy and personal priorities.
This article provides general medical information and does not replace personalised advice from a qualified healthcare professional.
References
Jarai MZ et al. Aquablation versus laser enucleation of the prostate: a systematic review and pairwise meta-analysis. Frontiers in Surgery, September 2026.
Gilling P et al. Five-year outcomes for Aquablation therapy compared to TURP: results from the WATER randomised trial. Canadian Journal of Urology, 2022.
Bhojani N et al. Aquablation Therapy in Large Prostates (80–150 mL): Final WATER II 5-Year Clinical Trial Results. Journal of Urology, 2023.
Berjaoui MB et al. WATER versus WATER II 5-year update. BJUI Compass, 2024.
WATER III: A Prospective, Partially Randomized Trial of Aquablation versus Laser Enucleation. European Urology Focus, 2026.