The Visualized Urethral Mobility Profile in Stress Urinary Incontinence Described by Four-Dimensional Transperineal Ultrasound

OBJECTIVES To describe the urethral mobility during urine leaking in stress urinary incontinence (SUI) by transperineal ultrasound (TPUS) with urethral mobility profile (UMP) analysis. METHODS This was a prospective study of 380 women who had a cough stress test (CST) with TPUS. UMP software automatically placed six equidistant points from the bladder neck (Point 1) to the external urethral meatus (Point 6) and determined their x and y coordinates relative to the symphysis pubis. Urethral mobility vector of Points 1-6 (Vectors 1-6) and the distance between the six points and the symphysis (Dist. 1-6) were calculated and compared between the two groups. The visualized UMP was created by reproducing the positions of the six points at rest and on Valsalva. RESULTS Valid data of 188 women with SUI and 174 continent women were analyzed. The mean age of all 362 women was 49.3 years. Mean body mass index in the SUI group was significantly increased (23.8 vs 22.2 kg/m2 , P < .001). During CST, Vectors 1-6 and Dist. 2-6 were significantly increased (all P < .005) in the SUI group. The UMP showed the mid-urethral rotated down around the symphysis pubis. The upper urethral profile in the two groups was similar. But the gap between the mid-urethra and the symphysis was wider in the SUI group. CONCLUSIONS The visualized UMP illustrated the mid-urethral hypermobility in SUI by showing a wider gap due to the unstable connection between the mid-urethra and the symphysis pubis.