The Evolution of Endoscopic Endonasal Approach for Olfactory Groove Meningiomas

Abstract

BACKGROUND: There is controversy over the choice of optimal approach for olfactory groove meningiomas (OGM). The endoscopic endonasal approach (EEA) is one of the most recently described corridors, which provides direct access to the tumor base. OBJECTIVE: To detail the evolution of the endoscopic endonasal technique over the past 2 decades and demonstrate the impact of this evolution on patient outcomes. METHODS: This is a retrospective study based on a prospectively maintained database of consecutive cases of OGM operated on at our institution via EEA. For analysis, the whole cohort has been divided into 3 equal “eras” according to the time period during which the surgery happened, creating early, middle, and contemporary groups. RESULTS: Seventy-five patients were included, 25 in each group. The rate of postoperative cerebrospinal fluid leak significantly decreased over time (28%, 32%, and 8% in the early, middle, and contemporary groups, respectively, P = .020). The rate of postoperative encephalomalacia was significantly lower in more recent groups (24%, 16%, and 0% in the early, middle, and contemporary groups, respectively, P = .029), as was the time to resolution of postoperative brain edema (103.9 months, 87.3 months, and 16.8 months in the early, middle, and contemporary groups, respectively, P = .020). CONCLUSION: The endoscopic endonasal approach for OGM significantly evolved over time, achieving lower cerebrospinal fluid leak rates while providing a high rate of Simpson grade 1 resection. Technical improvements minimized the frontal lobe impact. Current data support EEA as a safe and effective corridor to treat OGM.