This study is designed as a prospective cohort study. Our hypothesis is that mid-urethral sling provides backstop for excessive swing motion of distal urethra and helps with urethral compression along its luminal axis.~Aim 1: Investigate the effect of mid-urethral sling on the urethral shape at rest and maximum Valsalva, in other words dynamic urethral shape.~Aim 2: Compare the effect of mid-urethral sling on urethral dynamic shape in women with successful surgical outcome (absence of stress urinary incontinence at 3 and 12 months after the surgery) and women with surgical failure (presence of stress urinary incontinence at 3 and 12 months after the surgery).
The purpose of this prospective cohort study is to investigate the effect of sling on urethral dynamic shape and motion using static and dynamic pelvic floor ultrasound and additionally compare the findings among women with successful vs failed surgical outcome.