Endoscopic Endonasal Skull Base Surgery: Case Series

Objective The different skull base lesions could be treated via endoscopic endonasal approaches (EEAs).

Methods A retrospective review of all transnasal procedures performed between 2010 and 2017 was made. Patients with pituitary tumors and those who were operated via transnasal microscopical approach were excluded. All possible data concerning types of pathology, approaches, levels of complexity, methods of reconstructions, complications, and outcomes were collected.

Results A total of 113 patients underwent surgery. There were 23 (20.35%) patients with craniopharyngiomas, 7 (6.19%) with chordomas, 10 (8.84%) with meningiomas, 27 (23.9%) with other different skull base tumors, 24 (21.23%) with meningocele, 10 (8.84%) with posttraumatic cerebrospinal fluid (CSF) leak, 6 (5.3%) with spontaneous CSF leak, and 6 (5.3%) with CSF leak after transcranial approaches. Twenty-four (21.24%) transsellar, 21 (18.6%) suprasellar, 40 (35.4%) transethmoidal, 7 (6.20%) transclival, 15 (13.28%) transsphenoidal, 5 (4.43%) transpterigoid, and 1 (0.89%) transcribriform approaches were performed. Patient’s age was between 16 and 76 years, with mean age of 46.65 years. The mean period of follow-up is 42.6 months. According to the complexity, 24 (21.23%) cases correspond to level IV; 47 (41.6%) to level III; 41 (36.29%) to level II, and 1 (0.89%) case to level I. Skull base reconstruction was performed with the use of allogenic and autological (free and vascularized flaps). More often, a pedicle vascularized nasal septal flap was used. But in three cases, a skull base reconstruction with pedicle vascularized pericranial flaps was performed. Among complications, there were one internal carotid artery and one A1 intraoperative damage. Both were cured without stroke. A postoperative CSF leak occurs in 13.28% of cases and was a reason of meningitis in 7 (6.19%) patients. All were cured. One patient developed a spinal arachnoiditis associated with meningitis due to long-term lumbar drainage placement. Neural injury occurs in one patient and was a reason of death. Among other complications, there were massive blood loss—four (3.54%) cases: three (2.66%) patients developed DVT and in one case, it was associated with pulmonary embolism. New endocrinological deficit was associated with DI formation in 5 (4.43%) and diencephalic syndrome in 1 (0.98%) patient. Mortality rate was 1.7%.

Conclusion EEAs are safe and effective. 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.