Prostatic hydroablation (Aquablation): A new effective ultrasound guided robotic waterjet ablative surgery for treatment of benign prostatic hyperplasia.

INTRODUCTION: Bothersome lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH) are increasingly common amongst ageing men leading to poor quality of life. Surgical treatment options targeted at the obstructing prostate are often required to relief the bladder outlet obstruction, following failure or discontinuation of medical therapies. Transurethral resection of the prostate (TURP) has been the mainstay and gold standard for benign prostate surgery for last few decades. Currently with technological advancements, numerous minimally invasive surgical therapies have been employed to provide effective symptom relief while minimalizing morbidities and preserving sexual function. Prostatic hydroablation (Aquablation) is a new technique which involves high velocity water jets used in non-thermal ablation of the obstructing prostatic tissue robotically delivered by a transurethral cystoscopic handpiece and guided by real time transrectal ultrasound imaging. Recent trials have shown that aquablation is safe and effective in the treatment of symptomatic BPH while maintaining sexual preservation.

METHOD: Aquablation using the Aquabeam system (PROCEPT BioRobotics, Redwood Shores, CA, USA) combines the precision of autonomous robotic execution in delivering high velocity waterjets via a cystoscopic handpiece with accurate anatomical prostatic mapping using real time transrectal ultrasound imaging. The initial part of the surgery involves careful treatment planning tailored to the prostatic anatomy with preservation of important landmarks nearby, then, high velocity waterjet streams are delivered to ablate the obstructing prostatic tissue without use of any heat. Following the ablation and removal of handpiece, a routine cystoscopic bladder washout is performed and haemostasis achieved with balloon tamponade from a 3 way catheter placed under tension empolying a custom designed catheter tensioning device.

RESULTS: Initial studies involving a few case series and a phase II trial demonstrated the safety and effectiveness of aquablation in treatment of symptomatic BPH. Subsequently, a large multicentre international prospective randomised blinded clinical trial (WATER) was conducted to assess the efficacy of aquablation versus TURP. Results from this pivotal trial showed non-inferior symptom relief compared to transurethral prostate resection but with a lower risk of sexual dysfunction. WATER II study was then conducted to assess the safety and feasibility from a multicentre prospective study of aquablation in the treatment of symptomatic large-volume BPH. The results from this study showed that aquablation is feasible and safe in treating men with men with large prostates (80-150 mL).

CONCLUSION: The current landscape of BPH surgical treatment should be individualized with a shared decision- making process based on prostatic anatomy and clinical parameters combined with patient's preferences to select the ideal treatment option for each patient. Aquablation is one such option that involves a robotically delivered hydroablation technique based on individualised real time ultrasonic prostatic mapping that can offer safe and effective treatment for symptomatic BPH while minimising sexual dysfunction. Larger trials with longer follow up data will be required to further validate the long term effectiveness of aquablation.