Endoscopic Endonasal Internal Carotid Artery Transposition Technique in Tumor With Parasellar Extension: A Single-Center Experience

BACKGROUND AND OBJECTIVES: Lateralization or mobilization of the internal carotid artery (ICA) during a midline approach is required to expose lesions behind or lateral to the ICA. However, there have been no published data regarding the surgical outcomes of the endoscopic endonasal internal carotid transposition technique (EEITT). This study aimed to analyze the relevant surgical anatomy around the ICA and propose a grading scheme of EEITT. METHODS: A retrospective review of patients who underwent EEITT at a single institution was performed. Based on structures that limited the ICA and intraoperative findings, an anatomically surgical grading scheme of EEITT was proposed. RESULTS: Forty-two patients (mean age 45.6 years, 57.1% female patients) were included. Of them, 29 cases (69.0%) were Knosp grade 4 pituitary adenoma, 6 cases (14.3%) were chordoma, 6 cases (14.3%) were meningioma, and a single case (2.4%) was meningeal IgG4-related disease. The EEITT was categorized into Grades 1, 2 and 3, which was used in 24 (57.1%), 12 (28.6%), and 6 (14.3%) cases, respectively. The most common symptom was visual disturbance (45.2%). The gross total resection rate in Grade 1 (79.2%) and Grade 2 (83.3%) was much higher than that in Grade 3 (66.6%). The overall rate of visual function improvement, preoperative cranial nerve (CN) palsy improvement, and postoperative hormonal remission was 89.4%, 85.7%, and 88.9%, respectively. The rate for the following morbidities was cerebrospinal fluid leakage, 2.4%; permanent diabetes insipidus, 4.8%; new transient CN palsy, 9.5%; permanent CN palsy, 4.7%; panhypopituitarism, 7.1%; and ICA injury, 2.4%. CONCLUSION: The EEITT is technically feasible and could be graded according to the extent of disconnection of limiting structures. For complex tumor with parasellar extensions, the distinction into Grades 1, 2, and 3 will be of benefit to clinicians in predicting risks, avoiding complications, and generating tailored individualized surgical strategies.