Assessment of Sling Characteristics After Transobturator Tape Placement Using Transperineal Ultrasonography: Relationship with Continence and Dyspareunia—A Cross-Sectional Study

Background/Objectives: Stress urinary incontinence (SUI) is a common condition that adversely affects women’s quality of life, and transobturator tape (TOT) surgery is one of the most commonly used treatments; however, the determinants of surgical success and postoperative complications remain incompletely understood. The aim of this study was to evaluate the association between postoperative transperineal ultrasound (TPUS) findings and surgical outcomes after TOT surgery for SUI, with particular emphasis on the relationship between sling arm morphology and postoperative dyspareunia. Methods: In this single-centre, cross-sectional follow-up study of a retrospectively identified cohort, 74 of 148 women who underwent TOT surgery between February 2019 and November 2024 were evaluated. TPUS was used to assess sling position, morphology, mobility, deformability, symphysis pubis–sling distance (SP-TAPE), urethral concordance, and bladder wall thickness. Patient-reported outcomes were evaluated using the I-QOL, UDI-6, IIQ-7, and OAB-V8 questionnaires. Factors independently associated with surgical success were identified using multivariable logistic regression analysis. Results: Objective surgical success was achieved in 71.6% of patients, whereas 91.9% reported satisfaction with the outcome. Concordant movement of the sling with the urethra (OR 8.963, 95% CI 1.612–49.857, p = 0.012), a shorter SP-TAPE distance during Valsalva (OR 0.337, 95% CI 0.181–0.629, p = 0.001) and a thinner bladder wall (OR 0.375, 95% CI 0.185–0.759, p = 0.006) were independently associated with objective success. Although sling arm morphology was not associated with surgical success (p = 0.797), among sexually active women (n = 61), curved sling arms were strongly associated with postoperative dyspareunia (75.0% vs. 27.3%; OR 8.00, 95% CI 2.54–25.22, p < 0.001). Bladder wall thickness correlated moderately with all four instruments (|r| = 0.551–0.667; all p < 0.001), inversely with I-QOL and positively with UDI-6, IIQ-7, and OAB-V8. Conclusions: Successful TOT surgery depends not only on appropriate sling localization but also on concordant sling–urethral movement and favourable dynamic sling behaviour. Although sling arm morphology was not associated with continence outcomes, its association with postoperative dyspareunia highlights the importance of evaluating both functional cure and postoperative quality of life. In the absence of preoperative data, this association should be regarded as exploratory. TPUS provides clinically valuable information for the postoperative assessment of outside-in transobturator slings; because all assessments were performed at a single visit, the relationships reported here are associations rather than demonstrated predictive relationships.