Percutaneous Tibial Nerve Stimulation for the Treatment of Overactive Bladder

PICHON RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; BARDACH, A.; CIAPPONI, A; REY-ARES, L.

Documento de Evaluación de Tecnologías Sanitarias

IECS

Año: 2012 p. 1 - 30

1668-2793

According to the International Continence Society, the Overactive Bladder (OAB) syndrome is defined as the presence of urgency, with or without incontinence usually associated with frequency and nocturia. Studies have reported a prevalence between 16 and 23%This pathology requires life-long treatment to control symptoms. The purpose of the treatment is to restore quality of life attaining balance between treatment effectiveness and its adverse effects. First-line treatment for OAB includes bladder and pelvic floor muscle training, and therapy with drugs such as oxybutynin and tolterodine. Second-line treatment options include the use of botulinic toxin, sacral nerve stimulation, augmentation cystoplasty and urinary diversion.Neuromodulation Therapy or Percutaneous Tibial Nerve Stimulation (PTNS) is proposed as a non-invasive therapeutic tool that may relieve OB-related symptoms.TechnologyThe posterior tibial point is electrically stimulated using a needle electrode and an electrode is placed on the foot, at the calcaneus.. Since the posterior tibial nerve is a root to the sacral plexus nerve, originated at the S2-S4 segment, its stimulation makes the sacral plexus nerve roots related with the control of the pelvic floor muscles and guts be retrogradely stimulated. Thirty-minute sessions are performed, weekly, bi or tri-weekly, and in some cases, daily as indicated in different protocols.Those patients, whom posterior tibial nerve stimulation was effective, require periodic treatment to maintain effects in time.PurposeTo assess the available evidence on the efficacy, safety and issues related coverage policies for the use of PNTS in patients with OB.MethodsA bibliographic search was carried out on the main databases: DARE, NHS EED, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs); health technology assessments and economic evaluations; clinical practice guidelines and coverage policies of other health systems.ResultsFour RCCTs (one with 4-week and the other 3 with 12-week follow ups), one meta-analysis conducted on cohort studies and one prospective cohort study, one technology assessment and two coverage policies were found.Two placebo-controlled RCCTs were conducted on 35 females and 220 patients (79% females) with OAB; the first trial considered as responders the patients who reported a 50% or greater reduction in incontinence episodes and it showed statistically significant differences between the e PTNS and the placebo group (12/17 (71%) Vs 0/15 (0%) p<0.001); while in the second trial, the treatment group showed an improvement in 42.7% of the patients in the PTNS group and in the 22.9% of the patients in the placebo group (p=0.003).One multicenter RCCT comparing PTNS with Tolterodine (4 mg daily) on 100 patients (90% females) showed that PTNS patient assessment of OAB symptoms was statistically significant for improvement or cure in 79.5% compared to 54.8% in the Tolterodine arm (p=0.01). Symptoms improvement was statistically significant within groups but not compared between groups. A prospective study with a 12-month follow up of the PTNS arm on 25 patients who continued receiving PTNS showed that the improvement in the parameters observed after 12 weeks of treatment persisted in the subsequent measurements.A fourth RCCT comparing bladder training and exercises to strengthen the pelvic floor muscles with and without supplementary treatment with PTNS showed post treatment statistically significant differences for the PTNS group in reduction of frequency p=0.013, nocturia p<0.001 and urge incontinence p<0.001.Finally, one meta-analysis conducted on the results of 6 non-controlled prospective trials and on the OrBIT trial PTNS arm showed a reduction in the number of daily voids of 2.8 (p<0.001) with an average improvement of 23%, decrease in episodes of nocturia of 1.2 (p=0.002; 41% average improvement), reduction in the incontinence episodes of 1.9 (p=0.023) with a 45% average improvement.The technology assessment concludes that if PTNS is not considered as a suitable technology to be used in their patients.The two coverage policies found consider PTNS as a medically necessary treatment that they will cover. One of them specifies that it will provide coverage in patients with symptoms 12-month or more long who have not responded to proper drug therapy plus behavioral therapy.ConclusionsPTNS might be a therapeutic alternative which has proved to moderately improve OAB symptoms. This information comes from good methodology quality controlled trials although adherence to long-term treatment is still uncertain when considering the technique characteristics and pathology chronicity. If used, it should be indicated in patients that did not respond to drug or behavioral therapy.