Radiological correlation between the anterior ethmoidal artery and the supraorbital ethmoid cell in relation to skull base

Abstract

Background: The anterior ethmoidal artery (AEA) is an important landmark in functional endoscopic sinus surgery. Iatrogenic injury may result in retraction of the artery into the orbit, with intra-orbital bleeding and possible blindness. Computerized Tomography (CT) scans are the gold standard in diagnosing paranasal sinus diseases. These scans are used as road maps while operating on the paranasal sinuses. We undertook this study to determine the reliability of identification of the artery on the coronal CT scan and to determine whether a correlation exists between the pneumatization of the suprabullar recess and the vertical distance of the artery from the base skull. Methods: 80 randomly selected CT scans were studied. The AEA was identified on each side and the vertical distance between the artery and the base skull was measured. The CT scans were divided into two groups based on whether the supraorbital cell was present or absent. These groups were each further subdivided into 3 groups depending on the vertical distance between the anterior ethmoidal artery and the base skull. Result: The AEA was reliably identified in 98.75 % of the cases. When the supraorbital cell was absent, the mean distance between the artery and the base skull was 1.2 mm; while when the cell was present, the mean distance was 4.52 mm which is statistical highly significant (p value < 0.05). Conclusion: The orbital beak and superior oblique muscle are reliable landmarks to identify the anterior ethmoidal artery. There exists a strong