ABSTRACT
Objective: To evaluate the feasibility of the endoscopic transnasal approach (ETA) and to analyze the outcomes and factors of this surgical technique in the management of the tumor invading the anterior skull base. Methods: A retrospective analysis was performed on 42 patients (31 males and 11 females, with mean age of 49 years) with sinonasal tumor invading the anterior skull base, who underwent ETA from June 2015 to April 2019 in Eye, Ear, Nose and Throat Hospital of Fudan University. Pathologically, there were 15 cases of squamous carcinoma (14 patients with T4bN0M0 and 1 patient with T4bN1M0) and 27 of olfactory neuroblastomas with Kadish stage C. Anterior skull base reconstruction was performed using the vascular pedicled nasoseptal mucoperiosteal flap and fascia lata. Brain non-contrast-enhanced CT was performed on the first postoperative day to exclude massive pneumocephalus, relevant brain edema and subarachnoid hemorrhage. Sinonasal contrast-enhanced MR was performed to assess the extent of the tumor removal. Kaplan-Meier analysis was used to calculate the overall survival (OS) and Cox multivariate regression analysis was used to determine the prognostic factors. Results: The mean duration of the surgery was 452 minutes. Total resection was performed in 36 patients (85.7%), subtotal resection in 2 patients (4.8%) with orbital involvement, partial resection in one patient (2.4%) with injury of the internal carotid artery. One patient (2.4%) underwent the second resection because of the tumor residual, two patients (4.8%) with unsure tumor residual. Mean follow-up was 20 months, with 17 months of median follow-up. One-, two-and three-year overall survival was 86.5%, 76.9% and 64.5%, respectively. For squamous carcinoma, one-, two-and three-year overall survival was 86.2%, 86.2% and 57.4%, respectively. For olfactory neuroblastomas, One-, two-and three-year overall survival was 86.9%, 75.3% and 67.8%, respectively. Multivariate analysis showed that tumor residual (P=0.001) and recurrence (P<0.01) were independent prognostic factors for survival. Conclusions: The ETA is safe and feasible in selected patients with sinonasal tumor invading the anterior skull base. Tumor residual and recurrence are independent prognostic factors for survival.