Randomized Trial of Percutaneous Versus Transcutaneous Tibial Nerve Stimulation in The Treatment of Refractory Overactive Bladder: Results From The TRANSPER Trial.

BACKGROUND: Overactive bladder (OAB) affects ~21% of the Spanish population. In patients, refractory to pharmacological therapy, tibial nerve stimulation-percutaneous (PTNS) or transcutaneous (TTNS)-is an established treatment option. As maintenance therapy is often required, home-based TTNS could reduce the healthcare burden. We compared the clinical efficacy of TTNS and PTNS in refractory OAB. METHODS: We conducted a prospective, randomized, double-blind, single-center, parallel-arm clinical trial (IRB 2022-598-1). Adults with pharmacologically refractory OAB were randomized to PTNS or TTNS using sealed envelopes; patients and evaluators were blinded to allocation. Stimulation was delivered at 200 μs pulse duration and 20 Hz frequency, with adjustable amplitude (0-10 mA). Treatment consisted of twelve weekly 30 min sessions. Primary outcomes were changes in OABq-SF symptom severity and quality-of-life (QoL) scores from baseline to 1 week after treatment, and Treatment Benefit Scale (TBS) responses. Secondary outcomes included bladder diary parameters. Statistical analyses included the chi-square, Wilcoxon, and Mann-Whitney U tests. RESULTS: Fifty patients were enrolled (TTNS, n = 23; PTNS, n = 27). Mean age was 56 years (SD 15.4), and 78% were women. Baseline characteristics were comparable. Both groups showed significant improvements in OABq-SF symptom (TTNS - 10.7, p = 0.001; PTNS - 11.7, p = 0.001) and QoL scores (TTNS + 11.5, p = 0.011; PTNS + 11.8, p = 0.003), with no significant between-group differences. Treatment satisfaction was similar (TTNS 69.6% vs. PTNS 63%). Bladder diary parameters improved in both groups. The main limitation was the modest sample size. CONCLUSIONS: TTNS was non-inferior to PTNS for the primary outcomes in patients with refractory OAB. TTNS may be a feasible home-based alternative, potentially reducing outpatient resource utilization. This clinical trial is registered in ClinicalTrial.gov, NCT ID not yet assigned.