Skull Base Tumors Treated via Endonasal Endoscopic Approaches. Case Series

Objective: A different tumors of the skull base could be treated via endoscopical endonasal routes. Due to the small number of each neoplasm we consolidate those heterogenic pathologies according to the type of surgical approach. The aim of this paper is to emphasize the effectiveness of endoscopic endonasal approach (EEA) in different skull base tumors treatment.

Methods: A retrospective review of patient's data with non-pituitary skull base tumors treated via EEA in the department of neurosurgery at Interregional Clinical Diagnostic Center in the period of 2010 to 2019 was made. Type of pathology, extent of resection, reconstruction technique, complications and outcomes were collected.

Results: A total of 54 patients with 19 different pathologies were operated. Among them were 17 meningiomas, 8 chordomas, 3 neuroendocrin carcinoma, 3 chondromyxoma, 3 metastasis, 3 SNAC, 2 SNUC, 2 ENB, 2 chondrosarcoma, 2 plasmocytoma, aggressive fibromatosis, angiofibroma, cylindroma, hemangiopericytoma, lymphoma, neurinoma, neuroenteric cyst, RCC, and vidian nerve neuroma by 1 case per pathology. There were 21 males and 33 females. Patient's age was between 19 and 76 years, with median of 51.8 years. 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. With regard to extent of resection there were 7 biopsies, 12 partial removals, 14 STRs, 6 NTRs, and 17 GTRs. In a vast majority of cases, a skull base reconstruction with pedicle vascularized nasoseptal flap was made. Reconstruction with pedicle vascularized pericranial flap was made in four cases and in one case with free pericranial flap. A postoperative CSF diversion with external drainage was applied in 20 (37.03%) patients and one of them required a subsequent shunting. Five patients (9.25%) developed a postoperative CSF leak and in two (3.7%) of them a meningitis was marked. Both were cured with delay extracranial complication in one case. Among other complications two (3.7%) patients had visual deteriorations, two (3.7%) cases of vascular injury including one basilar artery injury with brain stem stroke, two (3.7%) cases of CN VI palsy, two (3.7%) cases of brain tissue injury, five (9.25%) cases of excessive blood loss, two (3.7%) cases of DVT, and three (5.5%) patients developed a DI. Perioperative mortality rate was a 1.8% in this series.

Conclusions: Different skull base pathologies could be treated via EEA. Depends on their biology surgical treatment could be as a treatment of chose or provide the disease diagnosis and be a part of combined treatment. A learning curve is a critical point impacting on effectiveness of surgery and its outcomes.