Aquablation was first introduced in the US in 2017 after showing non-inferior outcomes to transurethral resection of the prostate (TURP). Non-resective treatment of the prostate has relatively poor efficacy in the treatment of urinary retention, whereas resection or enucleation of the prostate with electrocautery or laser has been associated with high success rates for treating urinary retention.  Current literature on outcomes of Aquablation in men with acute and chronic urinary retention is limited. We present our experience with Aquablation in men with and without urinary retention.

We conducted a retrospective review of all men undergoing Aquablation during our first year of experience - between May 2021 and May 2022. Aquablation was performed using the AquaBeamTM (PROCEPT BioRobotics, Redwood Shores, CA) system, in which a high pressure waterjet was used to resect obstructing prostate adenoma while sparing the ejaculatory ducts and verumontanum. The treatment area was mapped using cystoscopic and transrectal ultrasound (TRUS) guidance. After waterjet resection, bipolar cautery was used at the bladder neck. All patients were given antibiotic prophylaxis and kept overnight for continuous bladder irrigation, and the catheter was typically removed 2 days after surgery. Men were classified as having urinary retention if they required either intermittent or indwelling catheter or if they had a post void residual (PVR) ≥300mL prior to surgery.

A total of 95 men underwent Aquablation from May 2021-May 2022 (Table 1). 25 had a catheter preoperatively (Foley catheter, n=14, clean intermittent catheterization, n=11; mean duration 7 months, range 1-32 months) and an additional 14 had chronic symptomatic urinary retention with a PVR ≥ 300 mL (range 300-900 mL). Of the urinary retention patients, 35% had preoperative urodynamics, and 13/14 (93%) had a volitional bladder contraction (pdet@qmax ≥ 30 cmH2O). Remaining preoperative characteristics are described in Table 1. Mean operative time was 55 minutes and there was no correlation between prostate size and surgery duration (r=0.27). Failure of initial void trial  was more likely to occur in urinary retention patients who had a catheter preoperatively than those who had only an elevated PVR (42% vs 7%, p=0.03). Of those with urinary retention, 38/39 (97%) are currently voiding without a catheter.  There was no difference in complication rates between those with and without preoperative urinary retention (see Table 1).

A large meta-analysis has demonstrated the superiority of alpha-1-adrenergic receptor antagonists over placebo in promoting a successful trial of urination in men with AUR, with  success rate for first TWOC is 61%, and for a second trial after failure to void success was 29.5% for an overall success rate of 73% [1].  There is a paucity of of literature supporting the utility of prostatic urethral lift the the treatment of urinary retention, while water vapor therapy is associated with a catheter-free rate similar to that of simple void trial (70-79%) [2]. The non-resective prostatic artery embolization has an even lower success rate  than simple void trial.  

On the other hand, resective treatment has a substantially higher success rate in men with AUR or with chronic retention.  Transurethral resection of the prostate generally has a success rate ranging from 82-90%.  For photovaporization of the prostate, approximately 96% of men in retention are rendered catheter-free.  A recent large prospective study demonstrated success rates > 98% for treating acute and chronic retention with holmium laser enucleation of the prostate [2].

The literature is sparce with respect to the success rate of Aquablation for the treatment of urinary retention, with only one other report of only 20 patients with urinary retention. Our study is the largest to date of men with urinary retention, and supports the use of Aquablation for the treatment of urinary retention.  And with better preservation of sexual function compared to resection or enucleation with electrocautery or laser, Aquablation is an attractive option for sexually active men with urinary retention refractory to pharmacotherapy.

Aquablation is an effective surgery for treating men with urinary retention, with 97% achieving spontaneous voiding. This high success rate is better than those typically achieved with non-resective treatment, and equal to the success rate of other resective surgical treatments. Men requiring catheterization prior to surgery were more likely to fail their initial void trial, which may support the recommendation for a delayed trial of urination. Complication rate was not increased in men with urinary retention compared to those who did not have retention prior to surgery.

Yoon PD, Chalasani V, Woo HH; Systematic review and meta-analysis on management of acute urinary retention. Prostate Cancer Prostatic Dis 2015; 18:297-302.
Bassily D, Wong V, Phillips JL, et al: Rezum for retention-retrospective review of water vaporization therapy in the management of urinary retention in men with benign prostatic hyperplasia. Prostate 2021; 81:1049-1054.
Abo T, Finch W, Jefferson P: HoLEP for acute and non-neurogenic chronic urinary retention: how effective is it? World J Urol 2021; 39: 2355-2361.

Continence 7S1 (2023) 100837
DOI: 10.1016/j.cont.2023.100837