Objective: To determine the mechanism by which continence is restored following the colpo-needle suspension procedure.
Study design: During 1990-1991, 37 women underwent colpo-needle suspension for stress urinary incontinence. Urodynamic investigation was performed preoperatively and 6-12 months postoperatively, and the results of these tests were compared in order to define the changes that might be responsible for the restoration of continence.
Results: In comparing the preoperative and postoperative cystometric and uroflowmetric measurements, we found no significant differences in the values for bladder capacity, residual volume pressure rise on filling or standing, maximal urethral voiding pressure or peak flow rates. The urethral pressure profiles at rest did not result in statistically significant differences regarding urethral length or urethral pressure. The only such differences postoperatively were elevation of pressure. Transmission ratios on coughing and in the proximal half of the urethra were Q1, 100.3 (P < .001), and Q2, 100.4 (P < .002), respectively.
Conclusion: Colposuspension appears to correct genuine stress incontinence by repositioning the proximal urethra in the intraabdominal pressure zone, causing restoration of positive pressure transmission to the proximal urethra.