Olfactory groove meningiomas: An analysis based on surgical experience with 129 cases

Objective: The surgical strategy and outcome for 129 patients operated for an olfactory groove meningioma is retrospectively analyzed. Material and Methods: One hundred and twenty nine patients with an olfactory groove meningioma operated between the years 1987 and 2016 were analyzed on the basis of clinical and radiological factors that appeared to affect the conduct of surgery and its outcome. Each factor was given points, and the points were added to obtain a score. On the basis of the score, the tumors were divided into three grades. The grades determined the difficulties that could be anticipated during surgery. In the initial part of the series, a bifrontal craniotomy was done to resect the tumor in all patients. In the later half of the series, majority of the patients were operated by the use of a unifrontal craniotomy. The aim of surgery was to resect the tumor completely. Results: Total tumor resection was achieved in 86 patients, and subtotal tumor resection with less than 10% tumor left behind was achieved in 43 patients. Seven patients died in the immediate postoperative period. All patients where a subtotal tumor resection was done and where the patient died after surgery had a higher grade tumor. The average follow-up period was 82 months. There was non-symptomatic recurrence in 11 patients. Conclusions: The location and size of the tumor, extent and duration of visual symptoms, extent of tumor adjoining cerebral edema, encasement of anterior cerebral artery complex and extension in the extracranial compartment were more important factors that affected the outcome of surgery.