A COMPARISON OF BIOELECTRICAL AND MECHANICAL-ACTIVITY OF THE FEMALE URETHRA

Objective To determine the relationship between mechanical function and innervation of the urethra in order to clarify the effect of denervation and re-ennervation on urethral function. Design Prospective observational study. Setting Tertiary referral urodynamics unit. Subjects Thirty-six women, 21 with urinary symptoms and urodynamically proven genuine stress incontinence and 15 without urinary symptoms. Interventions All women underwent concentric needle electromyography of the urethral sphincter and urethral pressure profilometry at rest and during cough induced stress. Results Significant correlations were found between variables indicating denervation and reinnervation and improved resting urethral function. No correlation was found between these variables and urethral function under stress. Conclusions Our findings contradict current opinion that denervation of the urethral sphincter is associated with a reduction in the sphincteric function of the urethra, at rest or during stress, and suggest that denervation cannot therefore be a major aetiological factor in the development of genuine stress. incontinence.