Comparison of Transbasal, Endoscopic Endonasal, and Combined Approaches for Olfactory Groove Meningiomas: A Single Surgeon's Experience

Background The endoscopic endonasal approach (EEA) has become an accepted treatment for skull base tumors, yet its role for skull base meningiomas remains controversial. Here, we review the surgical results for olfactory groove meningioma (OGM) from a single surgeon using EEA, open transbasal approach, and a combination of both. We analyze the factors involved in approach selection.

Methods We retrospectively reviewed 28 OGM cases from a prospective database, which were divided into three groups based on surgical approach: transbasal (n = 15), pure EEA (n = 5), and combined transbasal-EEA (n = 8). Statistical analysis was performed where appropriate.

Results Eighteen patients (64.29%) presented with primary tumors, whereas 10 (35.71%) presented with recurrent ones. The combined group had the largest mean tumor volume (101.15 cm³, ± 71.24 cm³), while the transbasal group had the highest incidence of cerebral edema (73.33%, p < 0.001) and vascular involvement (66.67%, p < 0.001). Likewise, the transbasal group had significant lateral dural extension (73.33%, p < 0.001) and hyperostosis (73.33%, p < 0.001), with the lowest incidence of a cortical cuff (33.33%, p = 0.019). The pure EEA group had the smallest mean tumor volume (33.33 cm³, ±18.98 cm³), all with a cortical cuff and without optic nerve or vascular involvement. The combined transbasal EEA group all had recurrent tumors that invaded the sinonasal cavity with the highest incidence of optic nerve involvement (62.5%, p = 0.011). Gross-total resection was achieved in 100% of EEA, 80% of transbasal, and 62.5% of combined cases. CSF leak rate was 0% in the transbasal and combined groups, while there were two leaks in the EEA group (40%). Thirty-day readmission occurred in 13.33% of transbasal cases (2/15 cases), 40% of EEA cases (2/5 cases), and 25% of combined approach cases (2/8 cases). Modified Rankin's scale (mRS) was an average of 0.79 after transbasal, 2 after EEA, and 2.4 after combined approach (p = 0.0604).

Conclusion When addressing OGM, maintaining an armory of surgical tactics is paramount. In our practice, the transbasal approach remains the workhorse for removing larger, complex tumors. The role of EEA appears to be limited to smaller, appropriately selected tumors. EEA also plays an important adjunctive role in sinonasal inspection and skull base reconstruction when combined with the transbasal approach in recurrent OGMs invading the sinonasal cavity. Careful patient selection and individualized case analysis dictate optimal approach for best functional outcome and recovery.