The anterior ethmoidal artery: radio-anatomical comparison and its application in endonasal surgery.
High-resolution CT scans are able to determine with accuracy the location of the anterior ethmoidal artery in relation to the roof of the ethmoid. This investigation should greatly help functional endoscopic sinus surgery to avoid accidental injury of the artery and to coagulate the vessel in cases of severe epistaxis. This was a radio-anatomical study of the anterior ethmoid artery in order to assess the course of the artery prior to endoscopic cauterization. Eighteen ethmoid sinuses (nine heads) were dissected and high-resolution CT scans were performed in axial, coronal and sagittal planes. All anterior ethmoidal arteries were identifiable. The arteries were included in the roof of the ethmoid in eight cases. In three cases the arteries were prominent under the roof. In seven cases the dissection found the arteries distant from the roof. This anatomical feature was associated with pneumatization of the floor of the orbit. The correlation between CT scan and dissection was very satisfactory.