The perineal artificial sphincter for acquired incontinence--a cut and dried solution? Sixteen males with stress incontinence due to sphincter damage were investigated with videourodynamic studies after implantation of a perineal artificial urinary sphincter. Twelve patients were rendered dry; 4 remained incontinent, all of whom were shown by cystometry to have incontinence from detrusor instability. Of these, 2 also had stress incontinence proven by videourography. Detrusor instability was present in 9 patients before implantation; the instability worsened considerably in 2 patients and new instability was shown in another 2 patients. The limitations of the artificial urinary sphincter and the implications of detrusor instability in patients with an artificial sphincter are discussed. The artificial urinary sphincter is an extremely successful device for the treatment of acquired stress incontinence. 