Significance of urethral vascular pulsations in genuine stress urinary incontinence.

Urodynamic tracings of 100 women with genuine stress incontinence revealed urethra vascular pulsations in 15 patients, while 85 lacked vascular pulsations. The presence of vascular pulsations correlated with the maximal urethral closure pressure and identified a subgroup of genuine stress incontinence with normal sphincter strength and reflex activity. The only identifiable cause of stress incontinence for each patient in this group was a deficiency in the anatomic supports of the urethrovesical junction responsible for poor transmission of intra-abdominal pressure to the urethra during stress. Those patients lacking vascular pulsations demonstrated resting sphincter weakness as well as decompensation of the sphincteric mechanism with changes in bladder volume and posture. In most women with genuine stress incontinence, the etiology is a combination of urethral sphincter dysfunction and poor anatomic support of the urethrovesical junction.