aquablation

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Article of the week: Aquablation for benign prostatic hyperplasia in large prostates: 6‐month results from the WATER II trial

August 21, 2019/by Mihir Desai

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.

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.

Aquablation for benign prostatic hyperplasia in large prostates (80–150 mL): 6‐month results from the WATER II trial

Mihir Desai*, Mo Bidair^†, Kevin C. Zorn^‡, Andrew Trainer^§, Andrew Arther^§, Eugene Kramolowsky^¶, Leo Doumanian*, Dean Elterman**, Ronald P. Kaufman Jr.^††, James Lingeman^‡‡, Amy Krambeck^‡‡, Gregg Eure^§§, Gopal Badlani^¶¶, Mark Plante***, Edward Uchio^†††, Greg Gin^†††, Larry Goldenberg^‡‡‡, Ryan Paterson^‡‡‡, Alan So^‡‡‡, Mitch Humphreys^§§§, Claus Roehrborn^¶¶¶, Steven Kaplan****, Jay Motola**** and Naeem Bhojani^‡

*Institute of Urology, University of Southern California, Los Angeles, ^†San Diego Clinical Trials, San Diego, CA, USA, ^‡University of Montreal Hospital Center, Université de Montréal, Montréal, QC, Canada, ^§Adult Pediatric Urology and Urogynecology, P.C., Omaha, NE, ^¶Virginia Urology, Richmond, VA, USA, **University of Toronto – University HealthNetwork, Toronto, ON, Canada, ^††Albany Medical College, Albany, NY, ^‡‡Indiana University Health Physicians, Indianapolis, IN, ^§§Urology of Virginia, Virginia Beach, VA, ^¶¶Wake Forest School of Medicine, Winston-Salem, NC, ***University of Vermont Medical Center, Burlington, VT, ^†††VA Long Beach Healthcare System, Long Beach, CA, USA, ^‡‡‡University of British Columbia, Vancouver, BC, Canada, ^§§§Mayo Clinic Arizona, Scottsdale, AZ, ^¶¶¶UT Southwestern Medical Center, Department of Urology, University of Texas Southwestern, Dallas, TX, and ****Icahn School of Medicine at Mount Sinai, New York, NY, USA

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Abstract

Objective

To present 6‐month safety and effectiveness data from a multicentre prospective study of aquablation in men with lower urinary tract symptoms (LUTS) attributable to benign prostatic hyperplasia (BPH) with prostate volumes between 80 and 150 mL.

Methods

Between September and December 2017, 101 men with LUTS attributable to BPH were prospectively enrolled at 16 centers in Canada and the USA.

Results

The mean prostate volume was 107 mL. The mean length of hospital stay after the aquablation procedure was 1.6 days (range: same day to 6 days). The primary safety endpoint (Clavien–Dindo grade 2 or higher or any grade 1 event resulting in persistent disability) at 3 months occurred in 45.5% of men, which met the study design goal of < 65% (P < 0.001). At 6 months, 22% of the patients had experienced a Clavien–Dindo grade 2, 14% a grade 3 and 5% a grade 4 adverse event. Bleeding complications requiring intervention and/or transfusion were recorded in eight patients prior to discharge and in six patients after discharge. The mean International Prostate Symptom Score improved from 23.2 ± 6.3 at baseline to 6.7 ± 5.1 at 3 months, meeting the study’s primary efficacy endpoint goal (P < 0.001). The maximum urinary flow rate increased from 8.7 to 18.8 mL/s (P < 0.001) and post‐void residual urine volume decreased from 131 at baseline to 47 at 6 months (P < 0.0001). At 6 months, prostate‐specific antigen concentration reduced from 7.1 ± 5.9 ng/mL at baseline to 4.0 ± 3.9 ng/mL, a 44% reduction.

Conclusions

Aquablation is safe and effective in treating men with larger prostates (80–150 mL), without significant increase in procedure or resection time.

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

April 10, 2019/by Admin

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 DeGuenther¹⁶and 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, ⁷Addenbrooke’s 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

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Abstract

Objective

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.

Methods

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.

Results

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.

Conclusions

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

April 10, 2019/by Mark Speakman

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.

References

Plante, M, Gilling, P, Barber, N et al. Symptom relief and anejaculation after aquablation or transurethral resection of the prostate: subgroup analysis from a blinded randomized trial. BJU Int 2019; 123: 651– 60
Gilling, P, Barber, N, Bidair, M et al. WATER: a double‐blind, randomized, controlled trial of Aquablation^® vs transurethral resection of the prostate in benign prostatic hyperplasia. J Urol 2018; 199: 1252– 61
Gilling, P, Reuther, R, Kahokehr, A et al. Aquablation ‐ image‐guided robot‐assisted waterjet ablation of the prostate: initial clinical experience. BJU Int 2016; 117: 923– 9
Gilling, P, Anderson, P, Tan, A. Aquablation of the prostate for symptomatic benign prostatic hyperplasia: 1‐year results. J Urol 2017; 197: 1565– 72
Desai, M, Bidair, M, Bhojani, N et al. WATER II (80‐150 mL) procedural outcomes. BJU Int 2019;123: 106– 12
Aljuri, N, Gilling, P, Roehrborn, C. How I do it: balloon tamponade of prostatic fossa following Aquablation. Can J Urol 2017; 24: 8937– 40

Article of the week: WATER II (80–150 mL) procedural outcomes

January 23, 2019/1 Comment/by Admin

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.

WATER II (80–150 mL) procedural outcomes

Mihir Desai*, Mo Bidair^†, Naeem Bhojani^‡, Andrew Trainer^§, Andrew Arther^§, Eugene Kramolowsky^¶, Leo Doumanian*, Dean Elterman**, Ronald P. Kaufman Jr.^††, James Lingeman^‡‡, Amy Krambeck^‡‡, Gregg Eure^§§, Gopal Badlani^¶¶, Mark Plante***, Edward Uchio^†††, Greg Gin^†††, Larry Goldenberg^‡‡‡, Ryan Paterson^‡‡‡, Alan So^‡‡‡, Mitch Humphreys^§§§, Claus Roehrborn^¶¶¶, Steven Kaplan****, Jay Motola**** and Kevin C. Zorn^‡

*Institute of Urology, University of Southern California, Los Angeles, ^†San Diego Clinical Trials, San Diego, CA, USA, ^‡University of Montreal Hospital Centre, University of Montreal, Montreal, QC, Canada, ^§Adult Paediatric Urology and Urogynecology, P.C., Omaha, NE, ^¶Virginia Urology, Richmond, VA, USA, **University Health Network University of Toronto, Toronto, ON, Canada, ^††Albany Medical College, Albany, NY, ^‡‡Indiana University Health Physicians, Indianapolis, IN, ^§§Urology of Virginia, Virginia Beach, VA, ^¶¶Wake Forest School of Medicine,Winston-Salem, NC, ***University of Vermont Medical Centre, Burlington, VT, ^†††VA Long Beach Healthcare System, Long Beach, CA, USA, ^‡‡‡University of British Columbia, Vancouver, BC, Canada, ^§§§Mayo Clinic Arizona, Scottsdale, AZ, ^¶¶¶Department of Urology, UT Southwestern Medical Centre, University of Texas Southwestern, Dallas, TX and ****Icahn School of Medicine at Mount Sinai, New York, NY, USA

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Abstract

Objectives

To present early safety and feasibility data from a multicentre prospective study (WATER II) of aquablation in the treatment of symptomatic men with large‐volume benign prostatic hyperplasia (BPH).

Methods

Between September and December 2017, 101 men with moderate‐to‐severe BPH symptoms and prostate volume of 80–150 mL underwent aquablation in a prospective multicentre international clinical trial. Baseline demographics and standardized postoperative management variables were carefully recorded in a central independently monitored database. Surgeons answered analogue scale questionnaires on intra‐operative technical factors and postoperative management. Adverse events up to 1 month were adjudicated by an independent clinical events committee.

Results

The mean (range) prostate volume was 107 (80–150) mL. The mean (range) operating time was 37 (15–97) min and aquablation resection time was 8 (3–15) min. Adequate adenoma resection was achieved with a single pass in 34 patients and with additional passes in 67 patients (mean 1.8 treatment passes), all in a single operating session. Haemostasis was achieved using either a Foley balloon catheter placed in the bladder under traction (n = 98, mean duration 18 h) or direct tamponade using a balloon inflated in the prostate fossa (n = 3, mean duration 15 h). No patient required electrocautery for haemostasis at the time of the primary procedure. The mean length of stay after the procedure was 1.6 days (range same day to 6 days). The Clavien–Dindo grade ≥2 event rate observed at 1 month was 29.7%. Bleeding complications were recorded in 10 patients (9.9%) during the index procedure hospitalization prior to discharge, and included six (5.9%) peri‐operative transfusions.

Conclusions

Aquablation is feasible and safe in treating men with large prostates (80–150 mL). The 6‐month efficacy data are being accrued and will be presented in future publications (ClinicalTrials.gov number, NCT03123250).

Editorial: Aquablating urological skills

January 23, 2019/by Peter Chin

Waterjet Ablation Therapy for Endoscopic Resection of prostate tissue (WATER) II (80–150 mL) procedural outcomes by Desai et al. [1] in this issue of the BJUI, reports the results of a robotically controlled cavitating procedure in a multicentre prospective trial that may have wider implications than relief of prostatic hyperplasia causing obstruction.

Management of the large prostate (>80 mL) is often a challenge for many practicing Urologists and requires practice, constant development, and improvement in endoscopic skills. As a result, many differing approaches have been developed and honed, modifying and improving varied skills in the urologist’s armamentarium to equip them to tackle the large prostate. The traditional TURP is recommended only for prostates of 35–80 mL (European Association of Urology [EAU] guidelines 2015). Whilst there are some Urologists who have developed their TURP skills to tackle larger prostates [2], for most other urologists, other procedures have had to be developed to address the very large prostate (>80 mL). As the authors of the paper report, holmium laser enucleation of the prostate (HoLEP) and photoselective vaporisation of the prostate (PVP) have evolved to enable treatment of the larger prostates endoscopically, but have limited penetrance due to the relatively significant learning curve and fellowship training requirements. Open simple prostatectomy (OSP) has good results but significant potential complications [3]. Robot‐assisted simple prostatectomy is being evaluated as another option [4], but requires an expensive robot and extensive training to develop the skill‐set required to perform the procedure. Laparoscopic simple prostatectomy (LSP) also requires extensive training and experience.

The authors [1] report impressive results of aquablation in these usually challenging large prostates. The mean operative time (OT) was 37 min, which is quick for a large prostate. The average length of stay was 1.6 days. The transfusion rate (TR) was 5.9%, which is higher than HoLEP (0–4%) [4], but is lower than OSP, PVP and LSP. It is important to note that the study involved 16 different sites (13 American and three Canadian) and showed that similar results were achieved across all sites irrespective of the experience of the operator, highlighting the very low learning curve for this procedure. Although this was only a single‐arm study with no control group, the authors have endeavoured to provide a comparison of OT, mean hospital stay and TR between aquablation and other procedures (OSP, PVP, HoLEP and LSP; table 5) based on published literature. Complication rates, operative and hospital metrics of aquablation appear to compare favourably with the current accepted means of managing the large prostate.

The use of balloon tamponade for haemostasis appears to hark back to the days of hanging a saline bag attached to an Indwelling Catheter (IDC) off the end of the bed after a monopolar TURP. Bladder traction was maintained for an average of 18 h. The authors report that fulguration was available to the surgeons in this trial, but none chose to use it as they felt that balloon tamponade was an effective haemostatic mechanism. Fulguration was preferentially avoided based on the WATER trial [5], where it was noted that anejaculation rates were twice as large in the aquablation with fulguration compared to the aquablation without fulguration group (16% vs 7%). The company (PROCEPT BioRobotics, Redwood City, CA, USA) even developed a novel catheter tensioning device (CTD) to assist with controlling the tension on the balloon tamponade demonstrating the old adage that ‘Necessity is the mother of Invention’. It would be interesting to see an objective assessment of discomfort from the balloon tamponade in future studies.

The results of this safety and feasibility trial suggest that aquablation is a quick procedure (37 min) for managing very large prostates. The complication rate is comparable to current endoscopic techniques (HoLEP and PVP) and appears superior to more invasive techniques (LSP and OSP). This study only reported perioperative measures and safety outcomes. No functional outcome or effectiveness measures were reported. The initial WATER trial [5] hints at possible effectiveness, but we will have to wait to see the results from this particular cohort of patients with large prostates (WATER II).

The short learning curve hints at a possible future. If the functional results from this cohort of large prostates treated by the aquablation robot compare favourably to current techniques, the patient with the very large prostate will no longer be only treatable by a few surgeons with an advanced and particular skill set.

Is this truly a quick, safe, effective procedure with no learning curve for large prostates? A randomised controlled trial of longer duration to assess functional outcomes, durability and complications may determine if the aquablation robot eventually renders the current surgical skill sets redundant.

References

Desai M, Bidair M, Bhojani N et al. Aquablation Procedural Outcomes for BPH in Large Prostates (80–150cc): Initial Experience. (WATER II {80‐150 ml} procedural outcomes). BJU Int 2019; 123: 106–12
Persu C, Georgescu D, Arabagiu I, Cauni V, Moldoveanu C, Geavlete P. TURP for BPH. How large is too large? J Med Life 2010; 15: 376–80
Gratzke C, Schlenker B, Seitz M et al. Complications and early postoperative outcome after open prostatectomy in patients with benign prostatic enlargement: results of a prospective multicenter study. J Urol 2007; 177: 1419–22
Pokorny M, Novara G, Geurts N et al. Robot‐assisted simple prostatectomy for treatment of lower urinary tract symptoms secondary to benign prostatic enlargement: surgical technique and outcomes in a high‐volume robotic centre. Eur Urol 2015; 68: 451–7
Gilling PJ, Barber NJ, Bidair M et al. WATER: a double‐blind, randomized, controlled trial of aquablation® vs transurethral resection of the prostate in benign prostatic enlargement. J Urol 2018; 5: 1252–61

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

May 10, 2016/by Peter Gilling

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

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Objective

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.

Results

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 (Q_max) 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 Q_max 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 Q_max 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.

Conclusions

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.