Cost-effectiveness of Antibacterial Envelope for Sacral Neuromodulation Infection Prevention

IMPORTANCE: Infections following sacral neuromodulation (SNM) implantation are associated with significant morbidity, device explantation, and increased health care costs. Use of an antibiotic-impregnated envelope may reduce this risk, but its cost-effectiveness remains uncertain. OBJECTIVE: The objective of this study was to determine whether universal or selective (salvage) use of an antibiotic envelope is a cost-effective strategy for preventing infections during SNM implantation. STUDY DESIGN: A Monte Carlo cost-effectiveness analysis (10,000 iterations) using a decision-analytic Markov model was developed from a third-party payer perspective. Three strategies were compared: (1) no envelope, (2) salvage use during reimplantation after infection, and (3) universal use at all SNM implants. The model incorporated costs, utilities, and clinical transition probabilities over a 3-year horizon. A willingness-to-pay threshold of $100,000 per quality-adjusted life year was applied. Sensitivity analyses, including 2-way threshold and probabilistic simulations, evaluated model robustness. RESULTS: Salvage envelope use was cost-effective with a minimum infection reduction of 0.54%, preventing 1 infection per 186 implants. Universal use became cost-effective at a 1.58% infection reduction (1 infection per 64 implants) or with a price decrease of $42.47 from the $895 base-case. Probabilistic sensitivity analysis favored salvage use in 55.2% of simulations and universal use in 44.8%. The "no envelope" strategy was rarely preferred. CONCLUSIONS: Selective use of the antibiotic envelope during reimplantation is cost-effective under current pricing. Universal use may become cost-effective with modest improvements in infection prevention or reduced cost. These findings support data-driven use of the envelope and may inform clinical guidelines and pricing policy.