Ultrasound evaluation of mid-urethral sling position: A potential predictor of outcomes and adverse effects.

OBJECTIVE: To evaluate mid-urethral sling (MUS) position and its association with postoperative outcomes and complications.

DESIGN: This was a prospective cohort study. 92 women who underwent MUS procedure with a median follow-up period of 11 months (interquartile range 5 to 24 months) were recruited.

PARTICIPANTS/MATERIALS, SETTING, METHODS: Two-dimensional trans-labial ultrasound (TLUS) with an endovaginal probe was used to visualize the urethral length (UL), sling distance to the bladder neck (BN) and to the urethra longitudinal smooth muscle (LSM).

RESULTS: Mean sling-LSM, UL and sling-BN distances were 5.97±2.04 mm, 28.66±3.19 mm, and 18.85±4.46 mm, respectively. Sling position relative to BN (proximal vs. middle vs. distal) was not associated with surgery outcomes and complications; however, mean sling-LSM in patients with exposure (4.3%) was significantly higher compared to those who did not experience exposure (8.80±1.9 mm vs. 5.8±2.0 mm, P=0.048). Moreover, the mean sling-LSM distance was associated with patient satisfaction (5.87±2.0 mm in satisfied patients with VAS>6 vs. 6.29± 2.1 mm in unsatisfied patients, p value= 0.043). Likewise, Patients who had worsened or showed de novo overactive bladder (OAB) symptoms (8.8%) had significantly higher mean sling-LSM distance compared to patients with improved OAB symptoms (6.52 ± 2.0 mm vs. 5.37 ± 1.9 mm, P=0.007). Mean sling-LSM distance was lower in patients with recurrent urinary tract infection (UTI), voiding dysfunction, and improved stress urinary incontinence whereas patients with dyspareunia after surgery had higher mean sling-LSM distance; however, these differences were not statistically significant.

LIMITATIONS: Both trans-obturator and retropubic procedures with or without concomitant prolapse surgery were assessed. Heterogeneity of the study population and performing pelvic floor ultrasound by a single urogynecologist were the limitations of the current study.

CONCLUSIONS: Ultrasound visualization of MUS is feasible and has the potential to predict outcomes and complications. High sling-LSM distance was associated with exposure and low sling-LSM distance with increased satisfaction rate, probability of voiding dysfunction and recurrent UTI.