RESUMO
BACKGROUND: Posterior tibial nerve stimulation (PTNS) is a minimally invasive approach with little adverse effects, but obtaining good results as shown in the different scales for the evaluation of the severity of incontinence. The aim of this study was to determine the effects of PTNS based on manometric determinations of the anal sphincter and severity during a period of treatment of 6 months (18 sessions). PATIENTS AND METHODS: A prospective interventional study of patients with fecal incontinence was performed. Subjects underwent one 30-min session every week for 12 weeks, followed by 6 sessions every 2 weeks. The effect on incontinence was evaluated by means of St. Marks and defecatory urgency scales, and manometry. RESULTS: Seventy-three patients were included. At baseline, 28.8% of the patients had a retention time of less than 1 min. At 12 weeks, 39.7% of the patients presented a retention time to 5-10 min and at 18 weeks 37% presented it over 10 min. At baseline, mean St Marks score was 15.1 + 5.1, improving after 12 weeks of treatment to 8.9 + 5 (p < 0.001). After 18 sessions, a greater improvement was observed up to 4 + 4.8 (p < 0.001). Maximum resting pressure showed a significant increase after treatment (mean increase 9.8 mmHg; p = 0.006). Similarly, maximum squeeze pressure also presented a significant augmentation (mean increase 25.3 mmHg; p = 0.002). CONCLUSION: Eighteen sessions of PTNS, divided in 12 weekly sessions and 6 sessions every 2 weeks, have shown to obtain benefits, reducing the St. Marks and the defecatory urgency scores, and increasing the manometric values.