Surg-25. surgical morbidity in relation to the surgical approach for olfactory groove meningiomas—a pooled analysis of 1016 patients and proposal of a new reporting system

Abstract BACKGROUND There is no consensus regarding whether a frontal or lateral approach is superior for resection of olfactory groove meningiomas (OGM). Objective: 1) To compare surgical approaches for microsurgical resection of OGMs for extent of resection and complication rates. 2) To develop a novel preoperative scoring system to guide choice of approach to decrease surgical morbidity. METHODS A PRISMA-guided pooled analysis of 20,672 surgical reports on OGMs published in the MRI era using search terms such as ‘olfactory groove meningioma’ and ‘surgery’. After title screening and removal of duplicates, we assessed 871 studies on surgical management of OGMs. Following exclusion criteria, 27 studies were chosen for the final pooled cohort analysis of reported patient outcomes. RESULTS The 27 studies identified a total of 1,016 individual patients who underwent open microsurgical resection of OGMs. The approaches used included: pterional/unilateral, bifrontal with variations, and anterior interhemispheric approaches. Across all studies, gross total resection (Simpson Grades I or II) was achieved in 91.4% of cases, and subtotal resection (Grades III and IV) was reported in 8.6% of cases. A cumulative 27% of surgical OGM patients sustained some form of complications. Minor complications 22.2% (CSF leak, seizures, infection, transient cranial nerve palsies, hydrocephalus). Major complications 4.7% (hemorrhage, ischemic infarct, malignant cerebral edema). Correlation between complications and the surgical approach was performed. Among 426 patients who underwent unilateral approaches, 14% experienced minor complications, and 2.1% experienced major complications. The 410 patients who underwent bifrontal approaches, 24.6% experienced minor complications, and 7% experienced major complications. CONCLUSIONS Unilateral approaches appear to have lower complication rates than bilateral approaches, however, the extent of resection is not uniformly reported, making it difficult to identify differences. We herein propose a novel preoperative imaging-based classification scoring system to help select the most suitable surgical approach to achieve lower post-surgical complication rates.