Interhemispheric approach for microsurgical removal of olfactory groove meningiomas.

Eighteen consecutive patients with olfactory groove meningiomas, with diameters ranging from 1.5 to 7 cm, underwent microsurgical tumour resection using a unilateral frontal interhemispheric approach. Unilateral frontal craniotomy, superior to the frontal sinus, exposing the superior sagittal sinus was performed. The ipsilateral frontal lobe was gently retracted laterally, and the tumour resected through the gap between the falx and the medial aspect of the frontal lobe, anteriorly to the genu of the corpus callosum. Gross total tumour resection was achieved in all the patients. There was no evidence of damage to the frontal lobes, the anterior cerebral arteries or the optic system. Compared with the more commonly applied subfrontal route, the interhemispheric approach has the advantages of sparing the frontal sinuses and providing excellent overview of the dissection of the anterior cerebral arteries and the optic system, as well as for the resection of tumour invading the frontal cranial base.