Transsphenoidal surgery assisted by navigation system

Microneurosurgical technique combined with precise localization of lesions, can minimize the invasiveness of neurosurgical procedures. This report describes the usefulness of the neuronavigation system in transsphenoidal surgery. Nineteen transsphenoidal operations for sellar lesions including pituitary adenoma, clival chordoma, Rathke's cleft cyst and suprasellar germinoma were assisted by the optical tracking system (OTS). Operations were performed either through the sublabial or the endonasal approach using an operative microscope and, to a certain extent, the endoscope. All five microadenomas were totally removed. The tumors could be precisely localized by the navigation system. Four out of seven macroadenomas were totally removed. The operations were assisted effectively by the excellent guidance to the lateral margin of the tumors and the internal carotid arteries provided by the navigation system. The endonasal approach, in which the surgeon looks through a nostril at the sellar floor obliquely, was especially facilitated by the three-dimensional view provided by the system. The navigation system, however, was not useful in estimating the amount of the suprasellar residual tumor because of the dislocation that occurred during the tumor removal.