Costs and outcomes of sacral nerve stimulation for faecal incontinence in New Zealand: a 10-year observational study

Background Faecal incontinence is a debilitating condition that affects more than 10% of New Zealanders. In well-selected cohorts, sacral nerve stimulation (SNS) offers a therapeutic option for patients refractory to conservative and other surgical treatments. The aim of this study was to define the clinical efficacy, rate of reinterventions and explants and healthcare costs associated with SNS in the New Zealand setting. Methods Clinical records of all consecutive patients undergoing SNS at Auckland District Health Board between 2008 and 2019 were retrospectively reviewed and paired with the results of a postal survey to 100 patients who had retained the implant at August 2019. Results Over the 10-year period, 142 patients underwent stage 1 SNS, of which 126 (88.7%) progressed to a permanent implant and 108 (76.1%) had retained the implant at a median follow-up of 41.2 months. SNS therapy significantly reduced weekly faecal incontinence episodes (P < 0.001), medication use (P < 0.001) and pad use (P = 0.01) at median 41.2 months. Complications were common, with infections in 9.2%, lead fractures in 4.9% and component migrations in 12.7%. The probability of retaining the same battery at 6.3 years was >90%. In total, reintervetion was necessary in 41.5% of the cohort. SNS therapy was expensive, costing >NZ$30 000 for implantation, increasing to >NZ$46 000 if a further reintervention was required. Conclusions SNS is an effective long-term therapy for faecal incontinence. However, it is expensive and associated with a high rate of reinterventions and explants.