The Urethral Motion Profile Before and After Suburethral Sling Placement

Purpose: We examined the effect of the Monarc™ suburethral sling on urethral mobility. Materials and Methods: We retrospectively studied the records of 54 consecutive women who received a Monarc suburethral sling between July 2005 and November 2008. All patients were examined by volume ultrasound preoperatively and at followup (average 0.7 years). Volume data sets were analyzed using post-processing software. Urethral mobility was described by vectors of movement from rest to a maximum Valsalva maneuver of 6 equidistant points marked evenly along the urethra from bladder neck (point 1) to external urethral meatus (point 6), as identified in the mid sagittal view. Measurements were made of point coordinates relative to the pubic symphysis dorsocaudal margin at rest and during maximal Valsalva maneuver. To determine the urethral motion profile we calculated mobility vectors of the 6 points using the formula, square root [(x_val - x_rest)² + (y_val - y_rest)²], where val represents the value during the Valsalva maneuver and rest represents the value at rest. We compared values before and after sling placement. Results: The subjective cure rate for stress urinary incontinence was 78% (42 cases). There was a statistically significantly decreased mobility at points 2 to 4, corresponding to the urethral central aspect (p = 0.002 to 0.018). No significant change in mobility was noted at the bladder neck and distal urethra (p = 0.39 to 0.89). Conclusions: Monarc suburethral sling placement decreases mid urethral mobility but does not seem to affect the bladder neck.