RESUMO
Introduction: Faecal incontinence (FI) is a common condition with a significant impact on quality of life (QoL). Neuromodulation treatments delivered by members of the multidisciplinary team including sacral nerve stimulation (SNS) and percutaneous tibial nerve stimulation (PTNS) are options for FI refractory to conservative management. The aim of this study was to assess whether a successful treatment with one neuromodulation modality corresponds with success in the other. Methods: A retrospective review of a prospectively managed neuromodulation database identified 15 patients who had undergone both PTNS and SNS. The definition of success of each treatment was a >50% improvement in any of The St. Mark's Incontinence Score, Manchester Health Questionnaire, or weekly faecal urgency or FI episodes. Results: Complete data from 12 patients was available for assessment and PTNS was delivered as the first treatment in nine patients. Overall, seven patients (58%) had successful PTNS treatment, with 10 (83%) having a successful SNS trials. Of the seven patients who had successful PTNS treatment, six patients (85.4%) went on to have success with SNS. Of the five patients who failed PTNS, four (80%) went on to have SNS success. Five (71%) of those who had positive PTNS outcomes had permanent SNS implantation as their final treatment decision. Conclusion: This study suggests that there is no clear relationship between successful PTNS treatment and an SNS trial period which may be explained by differing mechanisms of action or the potential placebo effect of PTNS. Further work is required to investigate any association in larger studies to inform clinical practice.
RESUMO
BACKGROUND: Posterior tibial nerve stimulation (PTNS) is a novel treatment for patients with faecal incontinence (FI) and may be effective in selected patients; however, its mechanism of action is unknown. We sought to determine the effects of PTNS on anorectal physiological parameters. METHODS: Fifty patients with FI underwent 30 min of PTNS treatment, weekly for 12 weeks. High-resolution anorectal manometry, bowel diaries and Vaizey questionnaires were performed before and after treatment. Successful treatment was determined as a greater than 50% reduction in FI episodes. RESULTS: Fifty patients with FI were studied; 39 women, median age 62 years (range 30-82). Compared with pretreatment, there were reductions in episodes of urgency (16.0 versus 11.4, p = 0.006), overall FI (14.5 versus 9.1, p = 0.001), urge FI (5.4 versus 3.2, p = 0.016) and passive FI (9.1 versus 5.9, p = 0.008). Vaizey score was reduced (16.1 versus 14.5, p = 0.002). Rectal sensory volumes (ml) decreased (onset 40.3 versus 32.6, p = 0.014, call 75.7 versus 57.5, p < 0.001, urge 104.1 versus 87.4, p = 0.004). There was no significant change in anal canal pressures (mmHg) (maximum resting pressure 41.4 versus 44.2, p = 0.39, maximum squeeze pressure, 78.7 versus 88.2, p = 0.15, incremental squeeze pressure 37.2 versus 44.1, p = 0.22). Reduction in FI episodes did not correlate with changes in physiological parameters (p > 0.05). Treatment success of 44% was independent of changes in manometric parameters (p > 0.05). CONCLUSIONS: PTNS has a measureable physiological effect on rectal sensory volumes without an effect on anal canal pressures. It also reduces FI episodes; however, this effect is independent of changing physiology, suggesting that PTNS has a complex mechanism of action.