Urodynamic Predictors of Outcome After Midurethral Sling for Female Stress Urinary Incontinence

Abstract

Introduction: Midurethral slings (MUS) are effective for stress urinary incontinence (SUI), but not all women achieve cure. This review identifies urodynamic parameters that predict surgical failure.

Methods: Systematic search of MEDLINE, Embase, and Cochrane (2010–2024) for prospective studies of women undergoing MUS with preoperative urodynamics (UDS) and ≥12 months follow-up. Predictors: Valsalva leak point pressure (VLPP), maximum urethral closure pressure (MUCP), and detrusor overactivity (DO). Primary outcome: negative cough stress test post-surgery.

Results: Sixteen studies (n=3,247) were included. Low MUCP (<30 cmH2O) was associated with lower cure rate (68% vs. 86%, OR 0.37, p<0.01). VLPP <60 cmH2O showed similar association (OR 0.42). Preoperative DO did not predict failure (OR 0.91, p=0.67). Intrinsic sphincter deficiency (ISD) defined by MUCP<30 had sensitivity 44% and specificity 82% for failure.

Discussion: Low MUCP is the strongest urodynamic predictor of MUS failure, consistent with ISD pathophysiology. However, many women with low MUCP still achieve cure. Most studies excluded mixed incontinence, limiting generalizability. UDS did not alter treatment decision in most cases.

Conclusions: While low MUCP predicts worse outcomes, it does not contraindicate MUS. Routine urodynamics for uncomplicated SUI is not necessary. For women with very low MUCP, alternative procedures (autologous sling) may be considered.