Modified Transcondylar Approach for a Case of Hypoglossal Neurinoma: Technique

Kang, Maeng Ho; Chung, Hoon; Lee, Sang Pyung

Abstract

Hypoglossal neurinomas are very rare and those which simultaneously involve the intracranial and extracranial portions are extremely unusual. Using the modified transcondylar approach, the authors successfully removed a dumbbell-shaped hypoglossal neurinoma at the intracranial portion and extending to the anterior upper portion of the axis through the hypoglossal canal. After dividing the cervical musculatures into layers, the vertebral artery was mobilized by opening the foramen transversarium and removing the postero-lateral part of the right occipital condyle, the lateral mass of the atlas and the mastoid tip by means of a small lateral suboccipital craniotomy. This approach offers a wide surgical field and a direct approach to the skull base and upper anterior cervical spine. After total removal of the hypoglossal neurinoma, a very simple supplementary autogenous bone graft was performed between the occipital bone and the lateral mass of the atlas, using the corticocancellous bone fixed with small screws. Postoperatively, the tumor was removed totally and there was no limitation on the cervical rotatory movement. A review of cases of hypoglossal neurinomas and the surgical approaches employed is included in this paper.