Evaluation of the Contribution of CAS in Combination with the Subcranial/Subfrontal Approach in Anterior Skull Base Surgery.

In this study, 31 cases with different anterior skull base lesions mandating broad exposure, including the sphenoidal, parasellar, and clival region, were surgically treated using the frameless computer assisted surgery (CAS) system. The contribution of navigated surgery in relation to the broad exposure and direct visualization of this region rendered by the subcranial-subfrontal approach was evaluated. In group I, consisting of extensive tumors, the contribution of CAS was only given in five cases for the exposure of the tumor extensions located to the parasellar sphenoclival complex with concomitant distortion of the anatomic landmarks. No advantages were experienced in the more anterior locations along the ethmoidal compartment and frontal sinus. In the cases in group II, consisting of congenital anomaly implying fronto-orbital advancement and a meningoencephalocele as well as extensive mucoceles, the CAS was only helpful in those cases with an extremely aberrative anatomy in these regions.