NEUROLOGY & FEMALE UROLOGY

Long-term durability of percutaneous tibial nerve stimulation for the treatment of overactive bladder
MacDiarmid SA, Peters KM, Shobeiri SA, Wooldridge LS, Rovner ES, Leong FC, Siegel SW, Tate SB, Feagins BA
Alliance Urology Specialists, Greensboro, North Carolina, USA
J Urol. 2010; 183: 234-40

• Purpose: The Overactive Bladder Innovative Therapy Trial during phase 1 was a randomized trial demonstrating comparable effectiveness of percutaneous tibial nerve stimulation and extended-release tolterodine during 12 weeks of therapy for frequency, nocturia, urgency, voided volume and urge incontinence episodes. In this second phase of the Overactive Bladder Innovative Therapy Trial we assessed the sustained therapeutic efficacy of percutaneous tibial nerve stimulation in subjects with overactive bladder during 1 year.
  Materials and Methods: After 12 weeks subjects randomized to weekly percutaneous tibial nerve stimulation with Urgent((R)) PC were offered an additional 9 months of treatment with assessments at 6 and 12 months from baseline. Outcome measures included voiding diary data, overactive bladder questionnaires, global response assessments and safety assessments.
  Results: A total of 33 percutaneous tibial nerve stimulation responders continued therapy with 32 and 25 subjects completing 6 and 12 months of therapy, respectively. Subjects received a mean of 12.1 treatments during an average of 263 days, with a mean of 21 days (median 17) between treatments. Subject global response assessments showed sustained improvement from 12 weeks at 6 and 12 months, with 94% and 96% of responders, respectively. At 12 months mean improvements from baseline included a frequency of 2.8 voids daily (p <0.001), urge incontinence of 1.6 episodes daily (p <0.001), nocturia with 0.8 voids (p <0.05) and a voided volume of 39 cc (p <0.05). Overactive bladder questionnaire symptom severity was significantly improved from 12 weeks to 12 months (p <0.01) as well as from 6 to 12 months (p <0.01). No serious adverse events occurred.
  Conclusions: Statistically significant overactive bladder symptom improvement achieved with 12 weekly percutaneous tibial nerve stimulation treatments demonstrates excellent durability through 12 months. The durability of response demonstrates the effectiveness of percutaneous tibial nerve stimulation as a viable, long-term therapy for overactive bladder.

• Editorial Comment
  In this study, the authors reviewed the response of patients to percutaneous tibial nerve stimulation (TTNS) over a one year time period. Of the 44 subjects enrolled in the trial, 35 responded to the therapy and of those 35 patients, 33 chose to continue on with the treatment. As noted by the authors, this trial identified that the symptom improvements obtained after the initial 12 treatments were able to be continued with routine ongoing therapy. The authors identified that a longitudinal 30 minutes session every 3 weeks would help keep the symptomatic response durable.
  This is an important paper to review especially in view of the increasing popularity of this technology for the treatment of the overactive bladder. Its efficacy, when used with patients who are refractory to medication, raises the consideration for use as a first line therapy. The fact that after the initial 12 weeks sessions, a treatment every three weeks sustains the symptoms makes it an attractive alternative to daily anti-cholinergic therapy. The economic comparisons of the two long term results will be very interesting. Also exciting is the potential use for patients in the institutional setting in which the side effects of anti-cholinergics such as cognitive disorder, xerostomia, and constipation could be avoided by an every 3 week bedside treatment.

Dr. Steven P. Petrou
Professor of Urology, Associate Dean
Mayo School of Graduate Medical Education
Jacksonville, Florida, USA
E-mail: petrou.steven@mayo.edu