Harnessing the power of water

Neil barber headshot

Neil J Barber

Frimley Park Hospital, Frimley Health NHS Foundation Trust

The headline on the Sunday ‘Daily News’ at this years AUA in San Francisco read ‘Technology will continue to change urology practice, AUA president says’. He reflected in his presidential address that ‘urologists have historically been early adopters and adapters of new technology…….ongoing advances in machine learning, automation and robotics will continue to change for the better the way we practice urology’.

To my mind, aquablation of the prostate using the Aquabeam system (Procept Biorobotics, Ca) represents all that Dr Thrasher was alluding to. Currently the subject of evaluation through the Interventional Procedures Programme of NICE, the procedure involves the use of a high pressure water jet to remove prostate tissue, much like TURP and indeed lasers to disobstruct the bladder outlet and improve bothersome LUTS in men with symptomatic BPH. This ultrasound guided, robotic delivered procedure, is a real step change in this field, being the first surgical intervention that creates a TURP like defect through the prostate without the use of any heat energy.

Results from WATER, a global multicentred, double blind randomized study have confirmed safety and efficacy of aquablation but with some interesting potential advantages over TURP. In a world where urologists are becoming increasingly aware of men’s concerns about the possible, indeed likely, negative impact of prostate surgery on sexual function, aquablation appears to have a risk of anejacualtion of 7% when no heat energy is applied and no discernable impact on erectile function. Furthermore, in larger prostates (50 – 80ml in this study), aquablation led to greater and faster improvements in symptoms.

The 6 month data from WATER was the trigger for aquablation to get FDA approval in December last year and I will be presenting the one year data at BAUS. Meanwhile results from WATER II – aquablation of prostates with volumes 80 – 150ml was presented at the AUA with good results but a slightly high transfusion rate and studies are also running in France and another, OPEN WATER, in Europe – a prospective post marketing study for all comers.

Aquablation of the prostate using the Aquabeam system is easy and quick to learn. A standard biplanar transrectal transducer allows real time planning of the treatment zone and the delivery of the water jet to create the defect is very fast and minimally influenced by prostate size. This means a short learning curve and predictable procedure times. The software is self explanatory and easy to use, planning taking 10 minutes or so. The aquablation itself takes 3 to 5 minutes depending on the size of the prostate.

The challenge remains haemostasis. This is achieved with a thorough bladder wash out via a 26Ch standard resectoscope sheath (removing clot and prostate tissue) and balloon tamponade using a standard 22Ch 3 way catheter – held in place by a bespoke Catheter Tensioning Device (CTD). The volume of water in the catheter balloon is determined by preop prostate volume. As the procedure has evolved, less and less post op irrigant is being required and we are now at a point where next day TWOC is the norm.

Having performed some 70 cases or so now, it seems to me that the lack of heat energy is important in some of the differences seen in the outcome of patients compared to more standard approaches. Not only is there the hugely lesser chance of anejaculation, but once the post operative haematuria settles, patients see a rapid improvement in symptoms and impressively quick return to normal activities – more akin to the minimally invasive options out there. The lack of thermal damage means that persistent dysuria and secondary bleeding is not a reported feature of post op recovery.

As the pace of technological advance gets ever faster, so we, the surgical specialty that grasps innovation, now see a procedure that may change this field forever. There are undoubtably numerous potential advantages for this novel procedure to both healthcare systems and patients. A short learning curve where familiarity with trans rectal ultrasound images of the prostate and the ability to pass a resectoscope sheath under vision into the bladder is all that is required; a procedure time minimally influenced by prostate size allowing efficient use of OR time in an era of significant capacity issues; a procedure that achieves equitable bladder outlet disobstruction and symptom improvement to standard procedures and a surgical option that does so with a side effect profile on sexual function more akin to popular minimally invasive options such as Rezum– will aquablation sweep all before it?

We will see what the future holds. As achieving adequate haemostasis becomes more reliable, the prospect of a day-case procedure becomes tantalizingly closer. Procept Biorobotics are examining redesigns that will significantly speed up set up time and ease of use. Development continues for aquablation and whilst others focus on alternative minimally invasive approaches, this exciting technology represents the only innovative challenge to TURP and lasers.

See BJUI Knowledge module “Robotically assisted Aquablation for BPH”