Tag Archive for: bladder outlet obstruction


Article of the week: Symptom relief and anejaculation after aquablation or transurethral resection of the prostate: subgroup analysis from a blinded randomized trial

Every week, the Editor-in-Chief selects an Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an editorial written by a prominent member of the urological community. These are intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation. 

If you only have time to read one article this week, it should be this one.

Symptom relief and anejaculation after aquablation or transurethral resection of the prostate: subgroup analysis from a blinded randomized trial

Mark Plante1, Peter Gilling2, Neil Barber3, Mohamed Bidair4, Paul Anderson5, Mark Sutton6, Tev Aho7, Eugene Kramolowsky8, Andrew Thomas9, Barrett Cowan10, Ronald P. Kaufman Jr11, Andrew Trainer12, Andrew Arther12, Gopal Badlani13, Mihir Desai14, Leo Doumanian14, Alexis E. Te15, Mark DeGuenther16 and Claus Roehrborn17


1University of Vermont Medical Center, Burlington, VT, USA, 2Tauranga Urology Research, Tauranga, New Zealand, 3Frimley Park Hospital, Frimley Health Foundation Trust, Surrey, UK, 4San Diego Clinical Trials, San Diego, CA, USA, 5Royal Melbourne Hospital, Melbourne, Vic., Australia, 6Houston Metro Urology, Houston, TX, USA, 7Addenbrookes Hospital, Cambridge University Hospitals, Cambridge, UK, 8Virginia Urology, Richmond, VA, USA, 9Princess of Wales Hospital, Bridgend, Wales, UK, 10Urology Associates, P.C., Englewood, CO, 11Albany Medical College, Albany, NY, 12Adult Pediatric Urology and Urogynecology, P.C., Omaha, NE, 13Wake Forest School of Medicine, Winston-Salem, NC, 14Institute of Urology, University of Southern California, Los Angeles, CA, 15Weill Cornell Medical College, New York, NY, 16Urology Centers of Alabama, Birmingham, AL, and 17Department of Urology, UT Southwestern Medical Center, University of Texas Southwestern, Dallas, TX, USA




To test the hypothesis that benign prostatic hyperplasia (BPH) robotic surgery with aquablation would have a more pronounced benefit in certain patient subgroups, such as men with more challenging anatomies (e.g. large prostates, large middle lobes) and men with moderate BPH.


We conducted prespecified and post hoc exploratory subgroup analyses from a double‐blind, multicentre prospective randomized controlled trial that compared transurethral resection of the prostate (TURP) using either standard electrocautery vs surgery using robotic waterjet (aquablation) to determine whether certain baseline factors predicted more marked responses after aquablation as compared with TURP. The primary efficacy endpoint was reduction in International Prostate Symptom Score (IPSS) at 6 months. The primary safety endpoint was the occurrence of Clavien–Dindo persistent grade 1 or grade ≥2 surgical complications.


For men with larger prostates (50–80 g), the mean IPSS reduction was four points greater after aquablation than after TURP (P = 0.001), a larger difference than the overall result (1.8 points; P = 0.135). Similarly, the primary safety endpoint difference (20% vs 46% [26% difference]; P = 0.008) was greater for men with large prostate compared with the overall result (26% vs 42% [16% difference]; P = 0.015). Postoperative anejaculation was also less common after aquablation compared with TURP in sexually active men with large prostates (2% vs 41%; P < 0.001) vs the overall results (10% vs 36%; P < 0.001). Exploratory analysis showed larger IPSS changes after aquablation in men with enlarged middle lobes, men with severe middle lobe obstruction, men with a low baseline maximum urinary flow rate, and men with elevated (>100) post‐void residual urine volume.


In men with moderate‐to‐severe lower urinary tract symptoms attributable to BPH and larger, more complex prostates, aquablation was associated with both superior symptom score improvements and a superior safety profile, with a significantly lower rate of postoperative anejaculation. The standardized, robotically executed, surgical approach with aquablation may overcome the increased outcome variability in more complex anatomy, resulting in superior symptom score reduction.

Editorial: A novel robotic procedure for bladder outlet obstruction

We have become used to talking about robotic surgery in urology when we really mean robot‐assisted surgery. The novel aquablation procedure (AquaBeam®) for bladder outlet obstruction (BOO) described by Plante et al. [1] is executed by a robotically controlled waterjet system, conducting a pre‐planned image‐guided resection once the radiological parameters have been entered into the system. This is performed under real‐time ultrasonography guidance. It will deliver a standardized way of carrying out the surgery and will, to a large extent, take away the surgical learning curve whilst introducing a new imaging learning curve.

The present study [1] is an analysis of pre‐planned and exploratory subsets of patients from the WATER study [2], and confirms data from earlier studies [3,4]. The study suggests that, compared with TURP, aquablation is particularly effective in improving both LUTS and bother in the medium‐sized to larger prostate (50–80 mL) and in potentially more challenging prostates such as those with large middle lobes or middle lobe obstruction (judged at pre‐procedure cystoscopy).

It is suggested that the ability to map the resection plane surgically may enable the preservation of key anatomical landmarks and preserve normal sexual function. In this study, anejaculation occurred in only 2% of patients with larger prostates (>50 mL) in the aquablation group compared with 41% of comparable patients undergoing TURP (P < 0.001). The rate of anejaculation however appeared relatively higher in the overall aquablation group, at 10%, compared with 36% in the overall TURP group (P < 0.001). A prostate volume between 30 and 80 mL was an inclusion criterion for the WATER study. This procedure therefore appears to give the best possible rate of anejaculation in a resective surgical intervention in patients with a larger prostate and may have less advantage in patients with a smaller prostate.

Interestingly, the relative overall symptom relief advantage of aquablation over TURP was also not proven in men with smaller prostates; TURP may be equally effective at removing obstructing tissue in smaller as compared to larger prostates. It is not yet clear whether aquablation would not be recommended for prostates below a certain size. In the more recent WATER II study in 101 men with a mean prostate volume of 107 mL, aquablation was also shown to be feasible and safe in men with large prostates (80–150 mL) [5].

There will always be a possible downside to novel treatments and this may relate to poor radiological data entry which may, in turn, lead to sphincter damage, although this has not been an issue in the carefully controlled studies to date. There are also reports of troublesome postoperative bleeding in some cases, although haemostasis can be effectively achieved via a catheter balloon tamponade and traction device or by electrocautery [5,6].

Unlike most other surgical treatments for BOO, the resection times for aquablation are almost independent of prostate volume, although the overall operating time is similar to that of TURP, with the majority of the time being spent in the set up and image planning.

The principal study (WATER) [2] on which this sub‐analysis by Plante et al. is based is an example of a high‐quality randomized controlled trial but still represents data on only 116 patients undergoing aquablation and 65 undergoing TURP; therefore, more randomized controlled trial data and long‐term effectiveness studies are clearly needed. Formal urodynamic studies and trials in patients with even larger prostates would also be appropriate. In addition, there are still few published data on the cost‐effectiveness of aquablation, although it is likely to be in the range of higher‐cost laser ablation therapies.

With better radiology and machine learning or artificial intelligence, this technique may lead to truly standardized BOO surgery with more complete resection and may thereby reduce outcome variability.


  1. Plante, MGilling, PBarber, N et al. Symptom relief and anejaculation after aquablation or transurethral resection of the prostate: subgroup analysis from a blinded randomized trial. BJU Int 2019123651– 60
  2. Gilling, PBarber, NBidair, M et al. WATER: a double‐blind, randomized, controlled trial of Aquablation® vs transurethral resection of the prostate in benign prostatic hyperplasia. J Urol 20181991252– 61
  3. Gilling, PReuther, RKahokehr, A et al. Aquablation ‐ image‐guided robot‐assisted waterjet ablation of the prostate: initial clinical experience. BJU Int 2016117923– 9
  4. Gilling, PAnderson, PTan, AAquablation of the prostate for symptomatic benign prostatic hyperplasia: 1‐year results. J Urol 20171971565– 72
  5. Desai, MBidair, MBhojani, N et al. WATER II (80‐150 mL) procedural outcomes. BJU Int 2019;123106– 12
  6. Aljuri, NGilling, PRoehrborn, CHow I do it: balloon tamponade of prostatic fossa following Aquablation. Can J Urol 2017248937– 40


Video: Aquablation – image-guided robot-assisted waterjet ablation of the prostate

Aquablation – image-guided robot-assisted waterjet ablation of the prostate: initial clinical experiences

Peter Gilling, Rana Reuther, Arman Kahokehr and Mark Fraundorfer


Department of Urology, Tauranga Hospital, Tauranga, New Zealand


Read the full article


To assess the safety and feasibility of aquablation in a first-in-man study. Aquablation is a novel minimally invasive water ablation therapy combining image guidance and robotics (aquabeam®) for the targeted and heat-free removal of prostatic tissue in men with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH).

Patients and Methods

A prospective, non-randomised, single-centre trial in men aged 50–80 years with moderate-to-severe LUTS was conducted. Under real-time image-based ultrasonic guidance, aquabeam technology enables surgical planning and mapping, and leads to a controlled heat-free resection of the prostate using a high-velocity saline stream. Patients were evaluated at 1, 3, and 6 months after aquablation.


In all, 15 patients were treated with aquablation under general anaesthesia. The mean (range) age was 73 (59–86) years and prostate size was 54 (27–85) mL. A substantial median lobe was present in six of the 15 patients. The mean International Prostate Symptom Score (IPSS) was 23 and the maximum urinary flow rate (Qmax) was 8.4 mL/s at baseline. The mean procedural time was 48 min with a mean aquablation treatment time of 8 min. All procedures were technically successful with no serious or unexpected adverse events (AEs). All but one patient had removal of catheter on day 1, and most of the patients were discharged on the first postoperative day. No patient required a blood transfusion, and postoperative sodium changes were negligible. There were no serious 30-day AEs. One patient underwent a second aquablation treatment within 90 days of the first procedure. The mean IPSS score statistically improved from 23.1 at baseline to 8.6 at 6 months (P < 0.001) and the Qmax increased from 8.6 mL/s at baseline to 18.6 mL/s at the 6-month follow-up (P < 0.001). At 6 months, the mean detrusor pressure at Qmax decreased to 45 cmH20 from 66 cmH20 at baseline (P < 0.05), and the mean prostate size was reduced to 36 mL, a 31% reduction in size vs baseline (P < 0.001). No cases of urinary incontinence or erectile dysfunction were reported.


These preliminary results from this initial study show aquablation of the prostate is technically feasible with a safety profile comparable to other BPH technologies. The combination of surgical mapping by the operating surgeon and the high-velocity saline provides a promising technique delivering a conformal, quantifiable, and standardised heat-free ablation of the prostate. Advantages of this technique include reduction in resection time compared with other endoscopic methods, as well as the potential to preserve sexual function.


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