The effect of uterovaginal prolapse on urethrovesical pressure dynamics.

Complete urodynamic evaluations were performed on patients with severe uterovaginal prolapse with the prolapse protruding and after reduction with a pessary. These results were compared with those from patients with genuine stress incontinence without prolapse. There was a significant increase in urethral closure pressure in patients with prolapse on the assumption of a more erect posture or on Valsalva maneuver. The opposite relationship was observed in patients with genuine stress incontinence in whom the urethral closure pressure significantly decreased under similar conditions. These results strongly suggest that the mechanism of continence in patients with significant prolapse is urethral obstruction. Reduction of the prolapse with a pessary can differentiate those patients who will require urethrovesical neck suspension.