Sonographic assessment of compression effect on urethra following transobturator MUS

Abstract

The aim of this study was to investigate the relationship between compression effect exerted by the sling on the urethra using translabial ultrasound and the prognosis of sling surgery in women for stress urinary incontinence (SUI). We retrospectively reviewed 151 women with SUI who had undergone either a TVT-Abbrevo (n = 81) or TVT-O (n = 70) procedure. Preoperative and 12-month postoperative assessments including sonographic data, urinary symptoms and signs were compared. Objective and subjective success rates were assessed at 12months postoperatively. Overall, 140 patients (92.7%) were objectively cured and 138 patients (91.4%) were subjectively cured of SUI 12months after the operation with no significant differences between groups (p > 0.05). After both the TVT-Abbrevo and TVT-O procedures, the shortest distance between the tape and the urethral cavity line (TU) on straining (objective cure 4.1mm vs. 4.5mm, subjective cure 4.1mm vs. 4.4mm), the changes of the angle (∆) between the two arms of the sling (objective cure 15.8° vs. 20.8°, subjective cure 16.5° vs. 21.3°) and the gap between the sling and symphysis pubis (objective cure 9.9mm vs. 12.1mm, subjective cure 9.8mm vs. 12.4mm) were significantly smaller in the success group (p < 0.05). Analysis of ultrasound measurements in women reporting success and those reporting failure of the procedure showed the ∆TU (objective cure 1.6mm vs. 0.9mm, subjective cure 1.6mm vs. 1.0mm) and the angle on straining (objective cure 93.4° vs. 89.2°, subjective cure 94.3° vs. 88.9°) to be significantly bigger (p < 0.05). However, none of the assessed sonographic variables showed any significant differences between the TVT-Abbrevo and TVT-O groups. The change in distance between the tape and urethral cavity line in the center of the urethra in the mid-sagittal plane after straining is an effective indicator of the compression effect exerted by the sling on the urethra after a mid-urethral sling (MUS) procedure and may contribute to both objective and subjective cure rates postoperatively.