Endonasal Endoscopic Approaches in the Treatment of Skull Base Tumors

Objective: Pituitary adenomas as well as other different tumors of the skull base could be treated via endoscopic endonasal approaches (EEA). The aim of this paper is to emphasize the effectiveness of EEA in different skull base tumors treatment.

Methods: A retrospective review of patients with nonpituitary skull base tumors and lesions treated via EEA in the Department of Neurosurgery at Interregional Clinical Diagnostic Center in the period of 2010–2018 was made. Type of pathology, extent of resection, reconstruction technique, complications, and outcomes were collected.

Results: A total of 75 patients were operated. There were 30 males and 45 females. Patient’s age was between 19 and 76 years, with median of 51 years (±2.3). Due to the pathology, there were 21 (28%) patients with craniopharyngiomas, 12 (16%) with chordomas, 1 5(20%) with meningiomas, 26 (34%) with other different skull base tumors. With regard to the pathology’s location different types of endonasal approaches to the anterior, central and posterior skull base were used. Most of them were extended and required a multilayer reconstruction as a final step of surgery. In the vast majority of cases, a skull base reconstruction with pedicle vascularized nasoseptal flap was made. Free mucosal flap of the middle turbinate was a second option. Reconstruction with pedicle vascularized pericranial flap was made in 4 cases and in one case with free pericranial flap. A gross-total resection was achieved in 30 (39.47%) cases, near-total resection in 11 (14.47%) cases, subtotal in 15 (19.73%) cases, and partial in 13 (17.1%) cases. There were 7 (9.21%) biopsies performed. 17 (14.16%) patients developed a postoperative CSF leak and in 7 (5.83%) of them, a meningitis was marked. In six patients, meningitis was cured. But in one patient, a delay complication associated with long staying of external lumbar drainage occurred. It was a persistent multiple spinal epiduritis required a long-term treatment including administration of steroids. Complication was cured conservatively without any neurological deficit. A postoperative CSF diversion with external drainage was applied in 48 (40%) patients and two of them required a subsequent shunting. Other complications included visual deterioration in 2 (1.6%) patients, intraoperative carotid artery injury in 1 (1.6%) case, excessive blood loss in 4 (3.2%) patients, new endocrinological deficit developed in 7 (5.83%) patients, 1 (0.83%) patient developed an epistaxis, and 3 (2.5%) patients developed deep vein thrombosis (DVT) associated with pulmonary embolism (PE) in one patient. Perioperative mortality rate was a 1.3% in this series.

Conclusion: Endoscopic endonasal approaches could be effectively applied for the surgical treatment of nonpituitary tumors of the skull base. Dynamic endoscopy with bimanual dissection makes surgery similar to conventional microsurgery. Usage of vascularized pedicle flaps for skull base reconstruction in endonasal surgery reduces risks of postoperative CSF leak. A learning curve is a critical point impacting on effectiveness of surgery and it outcomes.

No conflict of interest has been declared by the author(s).