The high prevalence of OAB, the drive to expand treatment options, and the success of the tibial nerve as a therapeutic target led to the development of ITNS devices. ITNS devices deliver therapy through the same mechanism of action as percutaneous tibial nerve stimulation (PTNS), enabling stimulation of the nerve at home and eliminating the need for repeated visits to a clinic. To date, two ITNS devices have received FDA marketing authorization for the treatment of urge urinary incontinence: eCoin (Valencia Technologies) and Revi (BlueWind Medical). In addition, clinical trials are ongoing for investigational ITNS devices from Medtronic, Coloplast, Uro Medical, and BioNess. There is a high level of interest in ITNS devices by patients, providers, and the industry, which reflects positive momentum for expanding treatment options for our OAB patients. The recent new American Urological Association guidelines on OAB support shared decision-making with patients and a holistic approach where all treatment options are discussed and care is individualized.
Because PTNS and ITNS utilize the same mechanism of action, data from randomized trials of PTNS are applicable to ITNS devices. In this narrative review, a comprehensive literature search identified 10 randomized controlled trials (RCTs) of PTNS vs. sham or other guideline-recommended therapies for OAB. These studies provide high-quality evidence that consistently demonstrates the safety and efficacy of PTNS with superiority over sham and similar efficacy to anticholinergic medications. Patients receiving PTNS demonstrated improvements in OAB symptoms as well as quality of life and other patient-reported outcomes. Given the equivalent mechanism of action and shared nerve target utilized by ITNS, data for these PTNS RCTs provide high-quality evidence supporting the efficacy of ITNS for the treatment of OAB. Our purpose in this piece was to review the PTNS literature and provide an up-to-date descriptive summary. The PTNS data is relevant and important to consider as the literature specific to ITNS is growing and will take time to mature and demonstrate medium- and long-term results.
ITNS provides patient convenience and autonomy, offering an attractive, minimally invasive, patient-centered approach to targeting the tibial nerve to deliver the intended clinical benefit. While future studies are needed to fully evaluate the longer-term outcomes of ITNS, this is an exciting time for OAB patients.
Written by:
- Una J. Lee, MD, Urologist, Virginia Mason Medical Center, Seattle, WA, USA
- Emily Gillespie, PhD, Senior Principal Clinical Evidence Specialist, Medtronic, Minneapolis, MN, USA