Skull base surgery for malignant nasal and paranasal tumors involving anterior skull base

Abstract

We report here a retrospective study of 24 patients with malignant nasal and paranasal tumors who underwent anterior skull base surgery at the Department of Otolaryngology Head and Neck Surgery, Kurume University Hospital since 1984. All patients received surgery by the supraorbital transbasal approach. The criteria of this treatment are : tumor does not involve the cavernous sinus or brain, and intraorbital invasion, if any, is localized to one side, Pathologically they were 19 highgrade malignancies (15 squamous cell carcinoma, 2 rabdomyosarcoma, 1 adenocarcinoma and 1 anaplastic carcinoma) and 5 low-grade malignancies (3 olfactory neuroblastoma and 2 chondrosarcoma). Follow-up period ranged from 3 to 185 months (median 72 months). Facial incision was performed in twenty patients, and combined orbital exentration was performed in 19 patients. Complications were observed in 4 patients (local infection : 2, rupture of carotid artery, sepsis : 1). Fifteen patients died of the primary disease and the causes of death were: local recurrence: 10, distant metastasis death: 3, complication: 2. Five-year cause-specific survival rates determined by the Kaplan-Meier method were 54% (48% in high-grade malignancies and 60% in low-grade malignancies) In conclusion, anterior skull base surgery employed as a team approach is a safe surgical procedure. From our clinico-pathological observation dura was formed to be a strong barrier against tumor invasion. Therefore, if an en block resection of the tumor with dura is possible, it enables complete resection against a malignant nasal and paranasal tumor invading the anterior skull base.