An extreme lateral approach to intradural lesions of the cervical spine and foramen magnum.

Meningiomas and neurofibromas are the most common intradural extramedullary tumors of the foramen magnum and cervical spine. Many of these tumors are located ventral or ventrolateral to the spinal cord and medulla. Posterior approaches, although adequate for the management of most of these tumors, can sometimes result in incomplete removal of the tumor and exacerbation of the neurological deficits. Although the transoral and transcervical approaches provide a direct route to the tumor, the exposure of the lateral margins in the case of large tumors is inadequate. In addition, because of the removal of vertebral bodies, subsequent fusion may be necessary. In the present report, an extreme lateral approach to the foramen magnum and cervical spine for the removal of intradural tumors is described. The approach provides a lateral exposure of the tumor-cord/stem interface, thus permitting safe dissection without retraction of the cord. The entire longitudinal and lateral extent of the tumor and also its extradural extension can be can be managed by this approach. This approach can be considered in such a group of patients harboring entirely ventral or recurrent tumors for which the conventional posterior approach has failed. Six patients who underwent this procedure are described to illustrate its application.