Lateral approach to the anterior portion of the foramen magnum. Application to surgical removal of 14 benign tumors: technical note.

In surgery, better access to the anterior part of the foramen magnum with less risk to the lower brainstem can be obtained by lateral enlargement of the usual posterior opening. This requires exposure and control of the vertebral artery (VA) and the sigmoid sinus (SS) and, for further enlargement, medial transposition of the VA and section of the SS with inferior petrosal resection. This technique has been applied fully or partially in 14 cases of anteriorly located tumors of the foramen magnum. It widens exposure on the anterior aspect of the neural axis and allows work in a nearly frontal plane.