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Updated: Aug 17, 2026

Microvascular Decompression: Salient Surgical Principles and Technical Nuances
Published on: July 5, 2011
[Foramen magnum meningioma of ventral type]
I Yamakami1, A Yamaura, T Nakamura
1Department of Neurosurgery, Chiba University School of Medicine.
Abstract:
We reviewed the clinical findings and the surgical results of five cases of patients with foramen magnum meningioma of ventral type who underwent preoperative magnetic resonance imaging (MRI) and tumor removal by the posterolateral approach. Patients showed a variety of neurological symptoms and signs including dysesthesia of extremities, but the neurological diagnosis could not determine the dominant side of the tumor. MRI determined the dominant side of the tumor and this side was chosen as the side of the surgical approach. By MRI findings of the extent of the tumor in the posterior fossa and the spinal canal, patients were classified into three cases of craniospinal type and two cases of spinocranial type. The result of tumor removal by the posterolateral approach was a total removal in the two cases of spinocranial type and a "near-total" removal in the three cases of craniospinal type. There was no surgical mortality and the surgical morbidity was negligible. The foramen magnum meningioma of ventral type, especially of the spinocranial type, can be managed safely and satisfactorily by the posterolateral approach.
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