Retrospective Study of Sacral Neuromodulator Implantations in a French Hospital Center: Lifespan and Hospital Costs Assessment

Sacral nerve neuromodulation (SNM) is a safe and effective therapy for the management of fecal and/or urinary incontinence. The generators InterStim™ and InterStim™ II (Medtronic™) are non-rechargeable active implantable medical devices with a limited lifespan. The aims of this study were to assess the generators’ median lifespan for all indications and the long-term hospital costs of the therapy. This was a retrospective monocentric study that included 215 patients aged over 18 years who were treated by SNM for fecal incontinence and/or urinary incontinence. Lifespan was considered as the amount of time between definitive implantation and observed battery depletion by the surgeon and was assessed by the Kaplan–Meier method. Costs were assessed according to the activity-based pricing of the French public health care system. The median observed lifetime of stimulators implanted in our center was 7.29 years and 5.9 years for InterStim™ and InterStim™ II, respectively. The difference observed between the two generations was statistically significant. The modelling of primary implantation and renewal costs allowed us to observe that the decrease in the lifetime of Interstim™ II is associated with an increase in hospital costs over time. The retrospective study design is one limitation and we did not take into consideration stimulation’s settings. The InterStim™ II lifespan is shorter than the first-generation device. This is associated with an increase of the long-term hospital costs. Additional information about the new neuromodulator will be required to choose the most appropriate IPG for the patient while optimizing the costs.