Changes of bladder urodynamics after combined pelvic floor muscle training and intravaginal stimulation in women with stress urinary incontinence: a retrospective cohort study.

INTRODUCTION: Sling implantation increases bladder outlet resistance and consequently elevates voiding workload in patients with stress urinary incontinence (SUI). This study investigated whether a non-invasive approach-pelvic floor muscle strengthening combined with intravaginal stimulation (PFMT + IVS)-modulates voiding work through alterations in outlet resistance. METHODS: Cystometric data from 20 female patients with SUI who completed a home-based PFMT + IVS program were retrospectively analyzed. The intervention consisted of biofeedback-assisted pelvic floor muscle training and intravaginal electrical stimulation (20 min each, twice weekly for 3 months). Symptom severity and quality of life were assessed using the Urogenital Distress Inventory-6 (UDI-6) and Incontinence Impact Questionnaire-7 (IIQ-7). Urodynamic parameters and pressure-volume analysis (PVA) indices were evaluated before and after treatment. RESULTS: Following PFMT + IVS, patients showed significant reductions in UDI-6 (p < 0.001; N = 20) and IIQ-7 scores (p < 0.001; N = 20). Voided volume (Vvoid; p = 0.042), voiding time (Tvoid; p = 0.028), and the pressure-volume trajectory area (Apv; p = 0.044), a surrogate of voiding work, were significantly increased. In contrast, no significant changes were observed in voiding resistance (Rvoid; p = 0.089), voiding pressure (Pvoid; p = 0.306), or flow rate (Fvoid; p = 0.271). The increase in Apv correlated positively with the increase in Vvoid (r = 0.450, p = 0.046), and the increase in Vvoid correlated with prolonged Tvoid (r = 0.665, p = 0.001). CONCLUSION: PFMT + IVS appears to maintain adequate outlet resistance during storage while permitting effective relaxation during voiding, thereby preserving voiding pressure and flow. Although total work per voiding cycle increased, work normalized to voided volume remained unchanged, suggesting preserved voiding efficiency.