Effect of Second Sling Type on the Success of Repeat Procedures.

IMPORTANCE: The optimal surgical strategy after failed midurethral sling (MUS) surgery remains controversial, and robust comparative data are needed to guide the choice between repeating the same sling type and converting to an alternative approach. OBJECTIVES: The objectives of this study were to compare the effectiveness and safety of 4 redo MUS strategies and to assess whether sling-type conversion offers clinical advantages over same-type repetition. STUDY DESIGN: In this multicenter retrospective cohort study (2015-2025), 256 women undergoing redo MUS surgery for persistent or recurrent stress urinary incontinence (SUI) were included. Patients were categorized into 4 groups according to redo sling type: (1) tension-free vaginal tape-retropubic sling (RP)→transobturator sling (TO) (n=33), (2) RP→RP (n=38), (3) TO→ RP (n=92), and (4) TO→TO (n=93). The primary outcome was objective cure at final follow-up. Secondary outcomes included repeat failure, change in International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) severity category, and mesh-related complications. Inverse probability of treatment weighting (IPTW) was applied to adjust for baseline differences. RESULTS: Baseline characteristics were comparable across groups. In IPTW-adjusted analyses, sling-type conversion was associated with significantly higher objective cure rates compared with same-type repetition (83.2% vs 61.8%; OR, 3.44; 95% CI, 1.86-6.37; P=0.001) and lower repeat failure (16.8% vs 38.2%; OR, 0.29; 95% CI, 0.16-0.54; P<0.001). Symptom improvement favored switch strategies, with mild postoperative ICIQ-SF scores observed in more than 80% of conversion groups. Mesh-related complications were also reduced with switching (OR, 0.63; 95% CI, 0.40-0.98), particularly in early redo procedures. In recurrent SUI, the switch strategy continued to show benefit in early recurrence, while in late recurrence (≥36 mo), no clear advantage was demonstrated. CONCLUSIONS: Sling-type conversion after failed MUS surgery is associated with superior efficacy and improved safety, supporting an individualized, strategy-driven approach to redo surgery.