Percutaneous tibial nerve stimulation (pTNS): success rate and the role of rectal capacity
Two types of neuromodulation are currently practised for the treatment of fecal incontinence (FI): sacral nerve stimulation (SNS) and percutaneous tibial nerve stimulation (PTNS). This study compares these therapies, as no data exist to prospectively assess their relative efficacy and costs. The subjects of this study were two distinct cohorts undergoing SNS (between 2003 and 2008) or PTNS (2008-onwards) for FI. Clinical outcomes assessed at 3 months included incontinence scores and the number of weekly incontinence episodes. The direct medical costs for each procedure were calculated from the audited expenditure of our unit. Thirty-seven patients (94.6 % women) underwent permanent SNS and 146 (87.7 % women) underwent PTNS. The mean pre-treatment incontinence score (±SD) was greater in the SNS cohort (14 ± 4 vs. 12 ± 4) and the mean post-treatment incontinence scores were similar for the two therapies (9 ± 5 vs. 10 ± 4), with a greater effect size evident in the SNS patients. In a ‘pseudo case–control’ analysis with 37 “matched” patients, the effect of both treatments was similar. The cost of treating a patient for 1 year was £11 374 ($18 223) for permanent SNS vs. £1740 ($2784) for PTNS. Given the lesser cost and invasive nature of PTNS, where both techniques are available, a trial of PTNS could be considered for all patients.