POSTERIOR TIBIAL NERVE STIMULATION FOR OVERACTIVE BLADDER IN A NON-TRIAL SITUATION
L. CURTISS1, J. DUCKETT 2, M. BASU 3;
1London, Dover, United Kingdom, 2Medway NHS Fndn. trust, Gillingham, United Kingdom, 3Medway NHS Fndn. Trust, Gillingham, United Kingdom.
Introduction: Posterior Tibial Nerve Stimulation (PTNS) is increasingly used for women with refractory overactive bladder (OAB), as well as faecal incontinence. Systematic reviews of randomised trials evaluating the use of PTNS in OAB patients report a significant benefit over sham therapy , however there is very little data in the literature reporting on the use of PTNS outside of a trial situation. Evaluation of such “real world” data will provide information on the efficacy of PTNS in less highly selected women, as well as the effect of clinical confounders on success.
Objective: To evaluate OAB symptoms in women over a 12-week course of PTNS, and to assess whether clinical characteristics affect efficacy.
Methods: The study population consisted of 60 consecutive women with refractory symptoms of overactive bladder and/or faceal incontinence who underwent PTNS between Nov 2015 and Jan 2017 in a secondary care setting. Exclusion criteria included active urinary tract infection and those with neurological conditions. All subjects were enrolled on a 12-week course of PTNS. They underwent baseline and weekly Urinary distress inventory (UDI -6) scoring and weekly interview regarding their symptoms. The primary outcome measure was the change in UDI-6 score. Baseline clinical and demographic data were noted for each patient. The change in UDI scores was tracked on a week by week basis and analysed by symptoms and urodynamic diagnosis. A Wilcoxon matched pairs signed rank test was used to evaluate continuous paired data. A Fishers Exact test was used for discrete data. Formal ethical approval was not applied for since this was classified as a service evaluation under current UK regulations.
Results: 60 women commenced the 12-week course of treatment. 50 completed all 12 weeks with 9 dropping out due to lack of efficacy and another because of the time commitment of the treatment. The mean age of the women was 55.5 years (range 25-81). 97% (58/60) had symptoms of OAB and 15% (9/60) had symptoms of faceal urgency. The change in mean UDI score analysed by week for all women is plotted in fig 1. There was a significant improvement in mean symptom scores of those with paired 12 week samples from 9.9 at week 1 to 7.9 at week 12 (P=0.004). There was however no statistically significant drop in UDI-6 score between any incremental weeks. The greatest fall in mean UDI-6 score was between weeks 3 and 4 (10.4 vs 9.5, p= 0.18). The change in mean UDI-6 score between baseline and12 week was greater in women with concurrent bowel symptoms (n=11) than in those with OAB symptoms alone (2.60 vs 1.89), however this did not reach statistical significance (p=0.34). The change in mean UDI-6 score was greater in women with concurrent symptoms of stress incontinence compared to those with OAB alone (2.57 vs 1.58), however this did not reach statistical significance. The presence of proven detrusor overactivity at urodynamics had no effect on treatment efficacy (p= 0.39). 57% of the cohort either discontinued treatment due to lack of effect (n=9) or at the final treatment reported no improvement (n=25).
Conclusions: A 12-week course of PTNS leads to a statistically significant improvement in symptom scores in women with refractory overactive bladder. The clinical relevance of this however is less clear since over 57% of women in this cohort either discontinued or self reported no improvement at the end of the 12-week course. There were trends to show that women who had concurrent bowel symptoms or symptoms of stress urinary incontinence had a greater improvement in mean UDI scores, although these failed to reach statistical significance. The presence or absence of DO had no effect on treatment success.
References: 1. 1. Neurourol Urodyn 2013; 32(3): 206-214