Supplementary Material for: Impact of Obesity on Postoperative Complications After Lateral Skull Base Surgery: A Systematic Review

Introduction: The relationship between obesity and complications after lateral skull base tumor resection is not clear. There is conflicting evidence regarding the incidence of postoperative complications in this patient population. The purpose of this study is to examine the relationship between obesity and outcomes following lateral skull base tumor resection, Data Sources: PubMed, Embase, CINAHL, and Cochrane CENTRAL Methods: Included studies assessed the relationship between obesity and outcomes following lateral skull base tumor removal. Studies with ≤5 patients, pediatric patients, duplicate patient populations, or insufficient data were excluded. Two independent investigators reviewed each study for inclusion. A third reviewer served as a tie-breaker for any conflicts. Extracted data includes patient demographics, tumor pathology, surgical approach, and postoperative outcomes including incidence of CSF leak and other postoperative complications, length of stay (LOS), and readmission and reoperation rates. Descriptive statistics were used to compare postoperative outcomes for obese and non-obese controls. Results: 14 studies met final inclusion criteria. Nine studies evaluated the relationship between obesity and CSF leaks. Four studies found a significant increase in post-operative CSF leak in obese patients compared to non-obese controls. The remaining studies trended towards an increased incidence of CSF leak in the obese population however did not reach statistical significance. One out of seven studies found that obesity increased post-operative LOS, and one out of five studies found that obesity increased reoperation rates following tumor resection. Conclusions: Based on the results, obesity does not appear to increase length of stay, readmission, or reoperation rates after lateral skull base tumor resection. The relationship between obesity and post-operative CSF leak however warrants further analysis.