OBJECTIVEOpen and endoscope-assisted repair are surgical options for sagittal craniosynostosis, with limited research evaluating each technique’s immediate and long-term costs. This study investigates the cost-effectiveness of open and endoscope-assisted repair for single, sagittal suture craniosynostosis.METHODSThe authors performed a retrospective cohort study of patients undergoing single, sagittal suture craniosynostosis repair (open in 17 cases, endoscope-assisted in 16) at less than 1 year of age at Monroe Carell Jr. Children’s Hospital at Vanderbilt (MCJCHV) between August 2015 and August 2017. Follow-up data were collected/analyzed for 1 year after discharge. Surgical and follow-up costs were derived by merging MCJCHV financial data with each patient’s electronic medical record (EMR) and were adjusted for inflation using the healthcare Producer Price Index. Proxy helmet costs were derived from third-party out-of-pocket helmet prices. To account for variable costs and probabilities, overall costs were calculated using TreeAge tree diagram software.RESULTSOpen repair occurred in older patients (mean age 5.69 vs 2.96 months, p < 0.001) and required more operating room time (median 203 vs 145 minutes, p < 0.001), more ICU days (median 3 vs 1 day, p < 0.001), more hospital days (median 4 vs 1 day, p < 0.001), and more frequently required transfusion (88% vs 6% of cases). Compared to patients who underwent open surgery, patients who underwent endoscopically assisted surgery more often required postoperative orthotic helmets (100% vs 6%), had a similar number of follow-up clinic visits (median 3 vs 3 visits, p = 0.487) and CT scans (median 3 vs 2 scans), and fewer emergency department visits (median 1 vs 3 visits). The TreeAge diagram showed that, overall, open repair was 73% more expensive than endoscope-assisted repair ($31,314.10 vs $18,081.47). Sensitivity analysis identified surgical/hospital costs for open repair (mean $30,475, SEM $547) versus endoscope-assisted repair (mean $13,746, SEM $833) (p < 0.001) as the most important determinants of overall cost. Two-way sensitivity analysis comparing initial surgical/hospital costs confirmed that open repair remains significantly more expensive under even worst-case initial repair scenarios ($3254.81 minimum difference). No major surgical complications or surgical revisions occurred in either cohort.CONCLUSIONSThe results of this study suggest that endoscope-assisted craniosynostosis repair is significantly more cost-effective than open repair, based on markedly lower costs and similar outcomes, and that the difference in initial surgical/hospital costs far outweighs the difference in subsequent costs associated with helmet therapy and outpatient management, although independent replication in a multicenter study is needed for confirmation due to practice and cost variation across institutions. Longer-term results will also be needed to examine whether cost differences are maintained.