Stress urinary incontinence, a new concept

Objective: A new concept is put forward to explain stress urinary incontinence (SUI). Urine continence depends on an intact strong internal sphincter and a reactive sympathetic activity. Study design: Thirty patients suffering from SUI were evaluated clinically and by urodynamic studies. During surgical repair of SUI, minute tissues were taken from the bladder neck and were examined microscopically after preparation and staining. Furthermore, examination of 15 postmortem specimens was done. Also a clinical trial was done to demonstrate the effects of sympathomimetics and alpha-blockers on the internal sphincter. Results: There is paucity and dispersion of collagenous and elastic tissues constituents of the internal sphincter in patients suffering SUI. alpha-Blockers lower the urethral pressure, while sympathomimetics increases it. Conclusion: Sudden increase of intravesical pressure overcomes a weak internal sphincter leading to leakage of urine. This initiates a reactive sympathetic quick response that increases the internal sphincter tone preventing further leakage.