Efficiency of Posterior Approach for Ventral and Ventolateral Foramen Magnum Meningiomas

Background: Foramen magnum (FM) meningiomas are uncommon lesions, consideredchallenging because of the vicinity of the medulla oblongata, the lower cranial nerves,and the vertebral artery. Surgery for meningiomas located in the region of the foramenmagnum anterior or anterolateral to the brainstem constitutes a formidable challengeand has been studied by various authors for many years through various approaches.Objective: To evaluate the efficacy of conventional posterior approach for ventral FMmeningioma. Patients and Methods: From September 2002 to June 2008, eight patientswith foramen magnum meningiomas arising from the anterior or anterolateral rim of theforamen magnum underwent operations in the Department of Neurosurgery at KasrAlainy Hospital, Cairo University, Egypt. All patients were operated on in a semi-sittingposition by use of a conventional suboccipital approach with a midline incision andextension of the craniectomy laterally toward the side of the tumor up to the occipitalcondyle. Results: Total tumor resection was achieved in six patients, and a subtotalresection of the tumor was performed in the other two patients due to inability to freevascular territories; in one of them, part of the tumor in relation to the vertebral artery(VA) and in the other, part in relation to posterior inferior cerebellar artery (PICA) wasleft behind. After surgery, one patient developed exaggerated lower cranial nerveweakness and two patient developed pseudomeningocele. The follow-up period was 24months; there has been no recurrence of the tumor or growth of the residual tumor.Conclusion: Ventral and ventrolateral FM meningiomas can be removed gross totallyand safely using a posterior suboccipital approach without the need for far lateralapproach.