Posterior Ethmoidal Artery: A Computed Tomography Analysis and New Classification

Introduction: In order to perform a successful and safe endoscopic frontal sinus surgery, it is essential to understand the anatomy of the ethmoidal arteries and their variations. Objective: To study the PEA using computed tomography (CT), analyzing its anatomical features and relations. Methods: The PEA was assessed by computed tomography (CT) in 100 consecutive subjects. Assessment. Measurements were taken including; the PEA length, the distance from the PEAs to the AEAs, to the skull base, to the optic nerve laterally and posteriorly, and to the basal lamella of the middle turbinates. Results: Within 100 patients (200 sides), the mean length of the PEA was 5.8±2 mm and the PEA was found embedded in the skull base in 98% of cases. The mean distance between the PEA and the optic nerve posterior was 9.2 ± 1.1 mm, while the mean distance between the PEA and the optic nerve laterally was 5.9±1.5 mm. The mean distance between the PEA and the anterior sphenoid wall was 6±2.4 mm and the mean distance between the PEA and the basal lamella of the middle turbinate was 20.36±4.2 mm. Conclusion: This study offers essential data for preoperative assessment of PEA in the way to improve surgeons’ and radiologist awareness of the PEA region for optimal safe EFSS with lower incidence of complications and recurrences.