MICROSURGICAL REMOVAL OF OLFACTORY GROOVE MENINGIOMAS VIA THE PTERIONAL APPROACH

Commonly used frontobasal approaches for microsurgical removal of olfa ctory groove meningiomas have certain disadvantages, such as late expo sure of the neurovascular complex located dorsal to the tumor, namely, the internal carotid artery, middle cerebral artery, anterior cerebra l artery, and the optic nerves. In addition, the frontal sinuses are f requently opened and there can be compression of the frontal lobes fro m significant spatula pressure. We report our experience with the pter ional approach for these tumors in 28 patients. All patients presented with hyposmia/anosmia; 20 had personality changes and 8 had visual de ficits. At surgery, after dissection of the sylvian fissure, the inter nal carotid artery, middle cerebral artery, anterior cerebral artery, and the homolateral optic nerve were exposed before removal of the pos terior tumor parts. Reduction of focal pressure was achieved by remova l of the contralateral tumor following partial resection of the falx a nd crista galli. Total tumor removal was obtained in all but 1 patient . One patient died of pulmonary embolism. The psychoorganic syndrome r esolved in all but 1 patient; visual deficits improved in 6 patients. There were no postoperative infections. We consider the pterional appr oach to be superior to others for these lesions because it provides ea rly exposure of the neurovascular complex, preservation of the frontal venous drainage, and avoidance of postoperative cerebrospinal fluid f istulae.