Background Anterior or anterolateral lesions of the lower third clivus and/or foramen magnum require a surgical exposure that provides a clear visualization of both pathological and normal anatomy without retraction of neural or vascular structures. The posterolateral approach permits access to the anterolateral intradural aspect of the brainstem. The aim of this study was to stress that there is no need for vertebral artery transposition, occipital condyle drilling, occipitocervical fixation or trans-oro-pharyngeal access to remove these lesions. Methods All five consecutive patients treated surgically for an intradural foramen magnum lesion in the Department of Neurosurgery at Angers University Hospital, between May 2012 and January 2015, were included in this retrospective study. In 4 cases, patients were referred to us for a second opinion after an initial surgical proposal at another institution. For all patients, the data collected were age at diagnosis, clinical signs, and quality of rostral and caudal exposure of the lesion, quality of resection, complications and postoperative neurological deficits. Results All patients were operated on with a control of the rostrocaudal part of the lesion, without touching the vertebral artery, or the use of occipital condyle drilling. There was no need for occipitocervical fixation. Total resection was achieved in 4 cases, subtotal resection in one. All had watertight dural closure with no dural patch, or postoperative neurological deficits. No recurrence occurred between 6 and 30 months after surgery. Conclusion Based on these results, the posterolateral approach was a simple, effective and safe procedure for anterior and anterolateral intradural lesion of the foramen magnum.
