Advanced neuronavigation in skull base tumors and vascular lesions.

Objective: The purpose of this study was to describe the usefulness of recent advances of neuronavigational technology in the management of skull base tumors and of vascular lesions, treated via a skull base approach.

Methods: In 16 patients (skull base meningioma n = 9, petrous apex epidermoid n = l, craniopharyngeoma n = 1, giant internal carotid artery aneurysm n = 1, basilar/vertebral artery aneurysm n = 2, brain stem cavernoma n = 2), "advanced" neuronavigation was used. In contrast to "conventional" neuronavigation, the information for the neurosurgeon was enhanced by the intraoperative screen display of 3-dimensional reconstructions of the lesion, vessels, nerves and fiber tracts at risk. The 3-dimensional reconstructions were obtained by preoperative manual or automated segmentation processes. In addition, different imaging modalities (computed tomography [CT] with magnetic resonance imaging [MRI], CT with CT angiography, T (l)- with diffusion-weighted MRI) were fused and shown on the screen.

Results: In the cases of tumors, "advanced" neuronavigation facilitated the approach (n = 4), contributed to tailor the approach (n = 2) and helped to identify hidden neurovascular structures (n = 9). In the cases of aneurysms, "advanced" neuronavigation allowed us to reduce the skull base approach to the needs of safe aneurysm clipping (n = 3). In both cases of brain stem cavernoma, "advanced" neuronavigation was deemed useful for definition of the best surgical approach in relation to the pyramidal tract and brain stem nuclei.

Conclusion: The authors' experiences suggest that neuronavigation, which displays 3-dimensional reconstructions of lesion, vessels, nerves and fiber tracts during surgery and makes use of image fusion techniques, is an important tool in the neurosurgical management of skull base lesions.