Mechanism of continence after modified Pereyra bladder neck suspension. Prospective urodynamic study.

Twenty females with genuine stress urinary incontinence who underwent modified Pereyra bladder neck suspension were urodynamically studied pre- and postoperatively in an attempt to determine the mechanism by which continence was restored. Detailed analysis demonstrated no significant change comparing the pre- and postoperative cystometry findings, uroflow parameters, maximal voiding pressure, urethral resistance, maximal urethral closure pressure, or functional urethral length. The only significant change identified as a result of the surgical procedure was an alteration of proximal urethral pressure transmission during stress from negative to positive gradients. It is concluded that the modified Pereyra bladder neck suspension restores continence by restoring proper urethral support with restoration of positive pressure transmission to the proximal urethra without causing outflow obstruction, changing functional length, or altering maximal urethral closure pressure.