Cranial neuronavigation in neurosurgery: assessment of usefulness in relation to type and site of pathology in 284 patients.

OBJECTIVE: Neuronavigation improves intraoperative topographical orientation in neurosurgery. We wanted to better define the practical value of this technique in relation to the pathology operated on and the types of cranial surgery that profit the most from it.
METHODS: Usefulness, interactive use and probably preventive effect of neuronavigation in cranial neurosurgery were assessed in a consecutive series of 284 patients on the basis of questionnaires with two- or five-point scale ratings by different neurosurgeons.
RESULTS: Neuronavigation was most helpful in tumors of the hemispheres (particularly the central area) not visible at the cortical surface or resembling normal white matter, and in endoscopic procedures within small ventricles or cysts with non-translucent walls or when vision was blurred by cloudy CSF. In the same pathologies and surgical procedures, the device was interactively used, taking advantage of the specific possibilities of interactive image-guided neurosurgery. A probably preventive effect of neuronavigation was noted in operations in eloquent areas; highest scores were given for intraaxial tumors of the central region. The subjective assessments of usefulness, interactive use or preventive effect were not dependent on the involvement of the neurosurgeons in this study.
CONCLUSION: We recommend this technique in resecting tumors in eloquent areas of the cortex or white matter, in approaching deep-seated processes not visible at the cortical surface, in defining borders of tumors resembling normal brain tissue, and in guiding endoscopes where ventricles are small or vision is blurred. This recommendation applies to any neurosurgeon familiar with the technique and managing neurosurgical cases requiring precise topographical orientation where normal anatomic landmarks are missing.