The artificial urinary sphincter (AUS) has proved its usefulness in the management of urinary incontinence in both male and female patients, being now considered the gold standard for the management of severe stress urinary incontinence in males with a high success rate (1).
The aim of the study is to first report the experience in 4 tertiary hospitals in Spain with the pre-connected, pre-filled and refillable AUS ZSI 375 PF (Zephyr Surgical Implants, Geneva, Switzerland).

Retrospective, nonrandomised, multicentre study. 
From December 2015 to March 2018, 23 male patients underwent refillable artificial urinary sphincter ZSI 375 PF implantation in 4 tertiary hospitals in Spain. 
Success rates were defined as dry (≤1 pad/day), improved (≥2 pads/day) and failed.
Data collection of clinical chart and clinical interview and exploration of the patients was performed and introduced in an Excel calculation worksheet. Statistical analysis was done through G-stat 2.0.

Median age was 69 years old (range 56-83). Open radical prostatectomy (RP) was performed in 14 patients (60.9%), laparoscopic RP in 4 (17.4%), robot-assisted RP in 3 (13.1%), open adenomectomy (Millin) in 1 (4.3%) and transurethral resection of the prostate in 1 (4.3%). External radiation therapy (ERT) was performed in 15 patients (and HIFU in one patient). Three patients previously had an AMS-800™, 1 patient had first a male sling and a Flow-Secure™ after, and 2 patients had botulinum toxin and Urolastic™ respectively. Cervicotomy was performed in 9 patients (twice in one patient), and 3 patients had prior history of recurrent urinary tract infections (RUTI). Median pad test was 1200 g (range 260-1533). Urodynamic study was performed showing urinary incontinence in all patients, plus overactive bladder in four (17.4%). No intraoperative complications were recorded, and patients were discharged 1-3 days after surgery. The device was activated 50 days after surgery on average (range 45-60). 4 patients are awaiting activation.
Refill was performed in 12 patients (1-3 times each) with a median volume of 0.4 ml. Nine of these patients have received ERT (including the patient after HIFU, 75%). 
Continence rate: 12 patients are dry (63.2%), 5 patients are improved (26.3%) and 2 patients failed (due to AUS explantation) (10.5%).
Persistent urinary incontinence has been diagnosed in 7 patients (36.9%), 5 with prior ERT (p=0.8104) and 3 with prior anti-incontinence surgeries (p=0.3505).
Complications: Erosion developed in 2 patients with prior RUTI and cervicotomy and the device was explanted (Clavien-Dindo IIIb) (10.5%); one patient had prior ERT. Postoperative hydrocele appeared in another patient which was managed conservatively (Clavien-Dindo I).

The first report of the use of an artificial urinary sphincter (AUS) was made by Foley in 1947. Since then, the AUS has proved its usefulness in the management of male urinary incontinence with a high success rate (1). Nonetheless, a high complications rate including erosion, infection and mechanical failure has been also reported, with a high percentage of patients needing reinterventions. 
Several devices have been marketed, but the most popular is the AMS 800™ Urinary Control System (Boston Scientific, Massachusetts, USA), composed by three components (cuff, pump and reservoir) which have to be assembled during the surgical procedure. In 2009, a device with two pre-connected (and pre-filled since 2015) components was marketed, which also allows to inject saline solution in the compensation pouch in order to increase the pressure if the patient presents with urinary leakage after implantation.
The marketing of a conceptually new pre-assembled and pre-filled artificial urinary sphincter intends to diminish mechanical failures (avoid the introduction of air bubbles in the system, prevent liquid leakage at the connections, elude passing needles that may damage the components). 
Recent studies suggest that prior radiation therapy and sling surgery may predict earlier reoperation in patients with artificial urinary sphincter and a higher complications rate (2,3). The small number of patients in this study did not achieve statistical significance, but the complications and risk factors are the same than with the AMS-800™.

The refillable artificial urinary sphincter ZSI 375 PF is a reliable alternative with good continence results and a low complications rate. Although previous radiation therapy might influence the achievement of complete continence after implantation, it is not an absolute contraindication. Careful information should be given to patients with previous urinary tract infections since they seem to have a higher risk for device infection and explantation.

Van der Aa F, Drake MJ, Kasyan GR, Petrolekas A, Cornu JN; Young Academic Urologists Functional Urology Group. The artificial urinary sphincter after a quarter of a century: a critical systematic review of its use in male non-neurogenic incontinence. Eur Urol. 2013 Apr;63(4):681-9. doi: 10.1016/j.eururo.2012.11.034.
Sacomani CAR, Zequi SC, Costa WHD, Benigno BS, Campos RSM, Bachega W Jr, Guimarães GC. Long-term results of the implantation of the AMS 800 artificial sphincter for post-prostatectomy incontinence: a single-center experience. Int Braz J Urol. 2018 Jan-Feb;44(1):114-120. doi: 10.1590/S1677-5538.IBJU.2017.0165.
Cohen AJ, Kuchta K, Park S, Milose J. Patterns and timing of artificial urinary sphincter failure. World J Urol. 2018 Jan 30. doi: 10.1007/s00345-018-2203-0.