Treatment of refractory overactive bladder with OnabotulinumtoxinA vs PTNS: TROOP trial

Introduction and hypothesis: We hypothesized that patients with refractory overactive bladder (rOAB) have similar improvement with percutaneous tibial nerve stimulation (PTNS) and OnabotulinumtoxinA (BTX). Methods: This multicenter cohort study compared BTX and PTNS in women with rOAB. Baseline information included Overactive Bladder Questionnaire (OABq) short form, Urinary Distress Inventory-6 (UDI-6), and voiding diary. Primary outcome was cure, defined as “very much better” or “much better” on the Patient Global Impression of Improvement (PGII) AND a reduction in OABq symptom severity scale (SSS) ≥10 at 3 months after treatment. Assuming 80% power to detect a ten-point difference in OABq-SSS, 80 participants were required per group. Results: A total of 150 patients were enrolled; 97 completed 3 months of therapy and were included. At baseline, BTX patients had more detrusor overactivity (70% vs 40%, p = 0.025), urgency incontinence (UUI; OABq-SSS#6 4 vs 3, p = 0.02, SSS 65 vs 56, p = 0.04), but similar health-related quality of life (HRQL 49 vs 54, p = 0.28), voids (7 vs 8, p = 0.13), and UUI episodes (2 vs 2, p = 1.0). At 3 months, cure rates were similar: BTX 50% vs PTNS 44.2% (p = 0.56). Both groups had improved SSS (−37 vs −29, p = 0.08) and HRQL (31 vs 24, p = 0.14). Patients receiving BTX had a greater improvement in urgency (ΔOABq-SSS#2–3 vs −2; p = 0.02) and UUI (ΔOABq-SSS#6–2 vs -1; p = 0.02). No characteristics were predictive of cure. Conclusions: BTX resulted in significantly greater improvement in urgency and UUI than PTNS, but no difference in success based on PGII and OABq-SSS, which may be due to a lack of power.