Artificial urinary sphincter

OBJECTIVE: To review the literature on artificial urinary sphincters, to describe their function, technique of implantation, indications, results and complications, and to analyze the possible utility of the prosthesis in the treatment of stress incontinence. METHODS: Medline (Index Medicus Online) and Embase (Excerpta Medica Online) were accessed to review the literature on artificial urinary sphincters published from 1974 (when the first artificial urinary sphincter was described by Foley) to October 1999. Of 322 articles identified, only those that described the patient selection criteria, type of prosthesis utilized, results and complications, and mean follow-up were considered. Articles describing historical aspects and new prototypes were also reviewed. Papers by the authors of the present article were excluded to avoid the bias of author preference. The bias of the language barrier, which occurs when articles published in Spanish, English and French are reviewed, was minimum. RESULTS: The AMS-800 is the only model available today. The results achieved are excellent if the indication is correct and perioperative management is careful and exact. The ideal candidate is one with genuine stress urinary incontinence and normal bladder function, although hyper or hyporeflexia is not an absolute contraindication if corrected before, during or after insertion of the prosthesis. The surgical technique is relatively simple and the only difficulty consists in the choice of the appropriate cuff and reservoir. The complications include urethral atrophy, erosion, infection and bladder instability, and are less frequent in women with stress urinary incontinence type III and in men incontinent after prostate surgery, and more frequent in patients with incontinence following pelvic trauma, incontinence due to congenital malformation and those with a neurogenic bladder. The mechanical failures of the prosthesis have diminished with its improved design. New hydraulic and non-hydraulic prototypes have been designed to reduce the complications, but the results are as yet unavailable. CONCLUSIONS: Today, patients with stress urinary incontinence have more possibilities to recover continence. If incontinence persists after all the available medical and surgical options have been attempted, one possibility still remains: the artificial urinary sphincter.