Urodynamic changes in bladder storage function after single‐incision mid‐urethral sling surgery for stress urinary incontinence

OBJECTIVE: This study evaluates changes in bladder storage capacity and function following mid-urethral sling (MUS) surgery in women with urodynamic stress incontinence (USI). METHODS: In this retrospective cohort study, 685 women with USI underwent MUS using single-incision sling devices (Ophira, Solyx, or I-Stop Mini) between 2015 and 2024 at a tertiary urogynecology center. Preoperative and postoperative assessments included validated quality-of-life (QoL) questionnaires, 1-h pad test, and multichannel urodynamic studies. Subgroup analysis was performed in women with greater baseline leakage burden (pad test ≥5 g). The primary outcome was change in cystometric capacity (CC); secondary outcomes included urodynamic parameters, QoL, and continence outcomes. Objective cure was defined as a 1-h pad test <2 g with no leakage on urodynamics and subjective cure as Urogenital Distress Inventory-6 Question 3 ≤1. RESULTS: At 1 year, objective and subjective cure rates were 89.5% and 87.0%, respectively. Although overall CC increased modestly (369.6 ± 118.8 to 377.1 ± 121.3 mL; P = 0.097), a significant improvement was observed in women with greater baseline leakage (374.1 ± 118.2 to 391.8 ± 122.5 mL; P = 0.005). Mean 1-h pad test weight decreased markedly (25.1-2.7 g; P < 0.001). QoL scores improved significantly across both success and failure groups. De novo detrusor overactivity occurred in 3.9% of patients. CONCLUSION: Mid-urethral sling surgery achieved high continence rates and significant QoL improvement in women with USI. Although overall postoperative changes in cystometric capacity were modest and did not reach statistical significance, patients with greater baseline leakage (pad test ≥5 g) demonstrated significant improvements in bladder storage parameters. These findings suggest a possible association between successful continence restoration and improved bladder storage function in selected patients. Further prospective studies are warranted to confirm these observations and clarify underlying mechanisms.