[Endoscopic endonasal sinus surgery using a navigation system for pituitary adenoma].

Hardy's operation using a microscope has long been the standard for treating pituitary adenoma. A new endonasal approach to the sella using an endoscope combined with a navigation system has been reported, which we used to conduct endocopic endonasal hypophysectomy from October 2000 to June 2003 in 11 patients with pituitary lesions. We introduced an angle-dependent navigation system, Neuro Navigator III. We approached the sphenoid sinus mainly via the hemilateral common meatus. The deviation of the nasal septum and sphenoidal septum was carefully evaluated to determine the optimal operating side. We concluded that the hemilateral common meatus route is useful because it is least invasive in endocopic endonasal hypophysectomy. Another route should be taken, however, if hemorrhaging is uncontrollable or the tumor is quite large. Navigation systems are quite effective in executing this operation safely. Angle-dependent navigation system is a good choice for this operation, considering its cost performance.