Transcutaneous Tibial Nerve Stimulation for Urinary Incontinence After Radical Prostatectomy

Official title

Efficacy of Transcutaneous Tibial Nerve Stimulation in Patients With Urinary Incontinence After Radical Prostatectomy: A Randomized, Double-Blind, Sham-Controlled Clinical Trial

Overview

Urinary incontinence (UI) after radical prostatectomy (RP) is a common postoperative complication that significantly affects quality of life. This study aims to evaluate the efficacy of active transcutaneous tibial nerve stimulation (TTNS), added to standard pelvic floor muscle training (PFMT), compared with sham TTNS, in patients with UI after RP. The study uses a randomized, double-blind, sham-controlled design. The primary outcome is incontinence severity measured by the 24-hour pad test. Secondary outcomes include voiding diary parameters, pelvic floor muscle strength (perineometry), quality of life, sexual function, and anxiety/depression levels.

Detailed description

The incidence of UI after RP ranges from 17-77% at 1 month, 7-53% at 3 months, and 3-38% at 6 months postoperatively, with full continence recovery typically taking up to one year. PFMT is the most commonly used conservative approach for managing post-RP UI; however, exercise protocols reported in the literature (contraction number, duration, position) are not standardized. In recent years, peripheral neuromodulation techniques, particularly TTNS, have increasingly been studied as an adjunct to PFMT. Existing literature on this topic is limited to retrospective studies without sham control groups, leaving it unclear whether the observed clinical improvement reflects a true neuromodulatory effect or the natural recovery process.

This study is the first prospective, randomized, double-blind, sham-controlled clinical trial comparing the efficacy of active TTNS added to PFMT versus sham TTNS added to PFMT.

Design: Participants are stratified by postoperative time (1-3 months, 3-6 months, 6-12 months) and randomized within each stratum using blocks of four at a 1:1 ratio into two groups.

Interventions - Group 1 (n=52): PFMT + Active TTNS, delivered via Enraf Nonius Myomed 932 at 20 Hz, 200 microseconds pulse width, continuous mode; once weekly, 30 minutes per session, for 12 weeks. Group 2 (n=52): PFMT + Sham TTNS, identical device/duration/frequency, using a four-electrode masking protocol with brief initial sensory stimulation followed by gradual current reduction to zero.

Both groups also follow a 12-week progressive home-based PFMT program.

Blinding: This is a double-blind trial. The participant and the outcome-assessing/data-collecting investigator are blinded to treatment allocation, and the statistician analyzes coded group labels blinded to group identity. The treating clinician, who monitors the motor threshold during stimulation, cannot be blinded but is fully isolated from clinical assessment processes.

Assessment time points: Baseline (T0) and end of 12 weeks (T1).

Sample size: Based on an a priori power analysis (Yamanishi et al. reference data), effect size d=0.585, alpha=0.05, 80% power yielded a minimum of 47 patients per group; accounting for 10% dropout, the final sample size was set at 104 (52 per group).

Interventions

• Device Active Transcutaneous Tibial Nerve Stimulation (TTNS)
  Active TTNS delivered via Enraf Nonius Myomed 932 at 20 Hz, 200 microseconds pulse width, continuous mode; once weekly, 30 minutes per session, for 12 weeks.
• Device Sham Transcutaneous Tibial Nerve Stimulation (TTNS)
  Sham TTNS using the same device and electrode placement; brief initial sensory stimulation followed by gradual current reduction to zero, so no current is delivered during the session. Once weekly, 30 minutes per session, for 12 weeks.
• Behavioral Pelvic Floor Muscle Training (PFMT)
  A 12-week progressive home-based pelvic floor muscle training program with graded contraction/relaxation durations and postural progression.

Primary outcome measures

• Change in 24-Hour Pad Test [Time frame: Baseline (T0) and Week 12 (T1)]

Secondary outcome measures (11)

• Change in Voiding Frequency (Three-Day Voiding Diary) [Time frame: Baseline (T0) and Week 12 (T1)]
• Change in Maximum Voluntary Contraction Pressure (Perineometry) [Time frame: Baseline (T0) and Week 12 (T1)]
• Change in Overactive Bladder Symptom Severity (OAB-V8) [Time frame: Baseline (T0) and Week 12 (T1)]
• Change in Quality of Life (Incontinence Impact Questionnaire-Short Form, IIQ-7) [Time frame: Baseline (T0) and Week 12 (T1)]
• Change in Anxiety and Depression Levels (Hospital Anxiety and Depression Scale, HADS) [Time frame: Baseline (T0) and Week 12 (T1)]
• Change in Sexual Function (International Index of Erectile Function, IIEF-15) [Time frame: Baseline (T0) and Week 12 (T1)]
• Continence Rate [Time frame: Week 12 (T1)]
• Treatment Response (Cure and Improvement Rates) [Time frame: Week 12 (T1)]
• Treatment Satisfaction Level (5-point Likert Scale) [Time frame: Week 12 (T1)]
• Procedure-Related Discomfort Level (5-point Likert Scale) [Time frame: Week 12 (T1)]
• Blinding Success [Time frame: Week 12 (T1)]

Eligibility criteria

Inclusion criteria

• Male patients aged 18-80 years
• Urinary incontinence greater than 8 g on the 24-hour pad test after radical prostatectomy
• Postoperative catheter removed, between 2 weeks and 1 year after surgery
• Willing to complete study questionnaires and able to understand the procedures, benefits, and possible side effects
• Able to provide written informed consent

Exclusion criteria

• History of urinary incontinence prior to radical prostatectomy
• History of conservative treatment after prostatectomy, including tibial nerve stimulation, magnetic stimulation, or electrical stimulation
• Prolonged indwelling urethral catheterization (more than 15 days)
• Anatomical/post-traumatic malformations or active skin conditions at electrode sites preventing electrode application or stimulation
• History of prior urological surgery
• Inability to voluntarily contract pelvic floor muscles on digital rectal examination per ICS terminology
• Currently receiving or having received radiotherapy
• Urethral stricture or active urinary tract infection
• Heart failure, pacemaker, or implanted defibrillator
• History of transurethral resection of the prostate (TURP) for benign prostatic hyperplasia
• Use of medications that may affect bladder function (antimuscarinics, duloxetine, tricyclic antidepressants, etc.)
• History of neurogenic bladder or peripheral/central neurological pathology
• Inability to attend treatment sessions regularly due to distance or physical limitations

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Turkey (Türkiye) · 1 center

• Pamukkale University Faculty of Medicine, Department of Physical Medicine and Rehabilitati — Pamukkale

Publications

• Akin Y, Yorulmaz EM, Kose O, Ozcan S, Gorgel SN, Tumer E. Impact of Posterior Tibial Nerve Stimulation on Early Continence Following Extraperitoneal Laparoscopic Radical Prostatectomy With Three Trocars. Neurourol Urodyn. 2025 Feb;44(2):360-366. doi: 10.1002/nau.25659. Epub 2025 Jan 6. PMID 39760411
• Yamanishi T, Mizuno T, Watanabe M, Honda M, Yoshida K. Randomized, placebo controlled study of electrical stimulation with pelvic floor muscle training for severe urinary incontinence after radical prostatectomy. J Urol. 2010 Nov;184(5):2007-12. doi: 10.1016/j.juro.2010.06.103. Epub 2010 Sep 20. PMID 20850831

Identifiers

NCT: NCT07742176 · E-60116787-020-895730

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗