Meningiomas Involving the Sphenoid Wing Outcome after Microsurgical Treatment – A Clinical Review of 73 Cases

Abstract

Sphenoid wing meningiomas represent a difficult to access subtype of intracranial meningiomas involving important neurovascular structures such as the optic nerve, cavernous sinus or carotid artery. They cause neurological compromises by direct compression of adjacent cranial nerves. Insidious and aggressive dural, bony, and orbital involvement produces several difficulties for adequate resection leading to higher rates of recurrence. This retrospective case analysis consists of 73 patients who were surgically treated for meningiomas involving the sphenoid wing, where a pterional approach was performed between April 2001 and February 2006. 51 women and 22 men with a mean age of 59.4 years were operated on. The follow-up period ranged from 3-75 months (mean 29.8 months). Patients were divided into the following groups based on the site of the tumor: group 1: outer part of the sphenoid ridge (lateral, n=16); group 2: middle part of the sphenoid ridge (intermediate, n=5); group 3: inner part of the sphenoid ridge (medial, n=22); and group 4: spheno-orbital meningioma (n=30). The majority of patients presented with visual impairment (55%), followed by generalized headaches (36%) and visual field defects (33%). Total microscopic tumor resection was achieved in 35 patients (47.9%). Visual acuity improved in 58% of the patients, with 23% returning to normal vision. Preexisting cranial nerve deficits remained unchanged in the majority of patients (79%) and improved in 18%. Temporary new cranial nerve deficits occurred in 6 cases, and 1 patient (1%) developed permanent third nerve palsy. The mortality rate was 3% (2 patients) and the rate of permanent nonvisual morbidity was 7% (5 patients). 12 patients (16%) received postoperative radiotherapy. In 6 of 7 patients who were observed for at least 1 year after radiotherapy, stable tumor volume was noted at the follow-up review (mean 30.2 months, range 16-50 months), which provides a tumor growth control rate of 86%. The overall recurrence rate was 15% (11 of 73 patients). The result of this study affirms the safety of microsurgical treatment strategies, so that sufficient tumor control can be achieved with minimal morbidity and satisfying functional results in most cases.