Three-dimensional ultrasonographic assessment of compression effect on urethra following tension-free vaginal tape and transobturator tape procedures

Objective To compare the anatomical difference using three-dimensional (3D) ultrasound between the urethra at rest and during straining, in women who have undergone a tension-free vaginal tape (TVT) or TVT-obturator tape (TVT-O) procedure for stress urinary incontinence (SUI). Methods We reviewed retrospectively 48 women with SUI who had undergone either a TVT (n = 24) or a TVT-O (n = 24) procedure. All women underwent urinalysis, pelvic examination, pad test, 3D perineal ultrasonography and personal interview about urinary symptoms within 1 year after surgery. Results After both TVT and TVT-O procedures, the area and longest and shortest diameters of the hypoechoic core of the mid-urethra were significantly smaller during straining than during resting (P < 0.01). The distance between tape and urethra was similarly smaller during straining in both groups. Analysis of ultrasound measurements in women reporting success (n = 40) and those reporting failure (n = 8) of the procedure showed the area and longest and shortest diameters of the hypoechoic core of the mid-urethra to be significantly smaller during straining than during resting in both groups (P < 0.01). However, the shortest diameter of the proximal and distal urethra during straining were significantly smaller only in the successful group (P < 0.01). Conclusion There are differences in urethral morphology during straining compared with during resting in women with TVT and those with TVT-O, regardless of tape procedure. A urethral compression effect of slings may have an important role in the continence mechanism. Copyright (C) 2012 ISUOG. Published by John Wiley & Sons, Ltd.