Morphological characteristics of the anterior ethmoidal artery in ethmoid roof and endoscopic localization.

OBJECTIVES: To provide anatomical data to help identify and locate the anterior ethmoidal artery (AEA) precisely during endoscopic procedures. METHOD: We dissected 15 adult cadaver heads, which provided 30 specimens, to study morphological characteristics, courses, and several types of variations. RESULTS: We found the average diameter of the AEA to be 0.80 +/- 0.24 mm. In 85.7% of the cases, the artery was seen between the second and third lamella. Other locations were over the roof of the frontal recess cells (10.7%) and the roof of the posterior ethmoid sinus (3.6%). The AEA ran parallel to the ethmoid roof and formed a slight curve. When viewed from the superior side, the angle formed by the long axis of the artery and the lamina papyracea was 60.5 degrees +/- 16.4 degrees. In 83.3% of the cases, the anterior ethmoidal canal (AEC) was identified as a separate canal, and in 16.7% the canal was embedded in the ethmoid roof. In 10 of the 30 cases (33.3%), the AEC presented some degree of dehiscence. CONCLUSION: As a result of these dissections, we found that the AEA's course in the ethmoid roof varies. The morphological characteristics-that the AEA runs parallel to the ethmoid roof, forming a slight posterolateral to anteromedial curve as it passes from the orbit to the cribriform plate-are the most reliable factors used to identify the artery during surgery.