Endonasal Endoscopic Surgery for Anterior Skull Base Pathologies: A Single Center's Initial Experience

Introduction: Over the past decade, there has been tremendous development in endonasal endoscopic approaches to anterior skull base pathologies. Here we review the first 3 years of our experience with purely endonasal endoscopic approaches in the treatment of a variety of benign and malignant pathologies of the anterior skull base.

Results: Between February 1, 2008 and February 1, 2011, 22 purely endoscopic procedures were performed for pathologies involving the anterior cranial base. The pathologies included malignant tumors, cephaloceles/CSF leaks, mucocele, meningioma, and hemangiopericytoma. The malignant tumors (n = 10) included esthesioneuroblastoma (n = 9), sinonasal undifferentiated carcinoma (SNUC) (n = 1), and adenocarcinoma (n = 1). In all, nine patients with esthesioneuroblastoma and the one patient with the SNUC, a negative margin resection was achieved. In the patient with the adenocarcinoma, this lesion extended intracranially and into the right orbit. Given the patient's age and morbidity associated with an orbital exoneration, a subtotal resection was planned. All 10 patients received postoperative radiotherapy; 3 patients also received adjuvant chemotherapy. The patient with adenocarcinoma developed a spinal metastasis that was treated with radiotherapy. With a mean follow-up of 23 months, all patients remain without evidence of disease. All patients with cephaloceles/CSF leaks (n = 7) underwent successful resection of the cephalocele and skull base reconstruction and perioperative intracranial (ICP) monitoring via a lumbar drain. Two patients had elevated ICP, one treated with diamox and the second with placement of a ventriculoperitoneal shunt (VPS). With a median follow-up of more than 19 months, none have had a recurrent CSF leak. Three patients underwent endoscopic resection of benign tumors including two meningiomas and one hemangiopericytoma. In one of the meningioma patients, a gross total resection was achieved. In the other patient, a planned subtotal resection was achieved, given the patient's age and her preoperative performance score. Residual tumor was treated with fractionated radiotherapy. In the patient with the hemangiopericytoma, an en bloc resection was achieved. There has been no recurrence or progression in this group of patients. Complications were noted in four patients. Postoperative pneumocephalus occurred in one patient and resolved spontaneously. Two patients developed complications following radiotherapy; one patient developed sinusitis requiring an endoscopic sinusotomy and one patient developed worsening dysosmia compared with her preoperative symptoms. One patient with a very anterior meningocephalocele required additional surgery with an external approach for recurrent frontal sinusitis. There were no cases of postoperative CSF leaks or meningitis.

Conclusion: Our series adds to the growing experience of endonasal endoscopic surgery in the treatment of skull base tumors. Additional studies on larger numbers of patients will help define the utility of this approach for patients with anterior skull base tumors.