Abstract
Indication and limitation of the skull base resection for the sinonasal malignancies was discussed in the anatomical and statistical point of view. 1) En bloc resection of the sinonasal primary site and the skull base was necessary for a good surgical result. 2) Orbital apex, optic canal, anterior clinoid process, sphenoid body, anterior border of foramen lacerum, carotid canal and clivus were thought as borderline sites against en bloc complete resection of the skull base. Becase the internal carotid artery had intimate relationship with these sites, respectively. 3) The outer surface of the cavernous sinus (CS) dura could be included in the en bloc resection of the skull base as one of the intracranial tissues. If the tumor invaded deeper and more extensive into the CS, the operative indication was decided whether internal carotid artery could be resected or not. 4) Combined resection of brain parenchyma and the skull base should be a candidate for a new method of en bloc resection of the skull base and sinonasal malignancies. 5) Resectability of the tumor was one of the most influencing factors to the outcome of the skull base surgery for the sinonasal malignancies: Incomplete resection of the tumor did not assure longer than 21-month survival for all the patient after skull base surgery and the resectability of the tumor was more significant for the cumulative 5-year survival rates than factors such as the site involved by the tumor or the histlogic type of the tumor.
