Anatomical knowledge of anterior ethmoidal artery is vital during endoscopic sinus procedures if complications are to be minimized. During its course the anterior ethmoidal artery crosses three cavities (the orbit, ethmoidal labyrinth and anterior cranial fossa of skull). The anterior ethmoidal artery enters the olfactory fossa through the lateral lamella of cribriform plate along the anterior ethmoidal sulcus. The bone over the anterior ethmoidal sulus is very thin and is at risk during endoscopic surgery. The relationship of the anterior ethmoidal artery to the roof of the ethmoid is highly variable and is at risk during endoscopic sinus surgeries. Identification of this artery is important in identifying frontal sinus outflow tract and superior limits of skull base.
Areas supplied by anterior ethmoidal artery:
It supplies the anteror ethmoidal cells and the frontal sinus. As it courses along the olfactory fossa it gives rise to meningeal vessels. This artery also supplies the anterior third of nasal septum and lateral nasal wall.
Stamberger reported that anterior ethmoidal artery may be in direct contact with skull base. This is particularly true if the roof of the ethmoid sinus is low. In majority of cases he reported that a bony mesentry could connect the anterior ethmoidal artery to the skull base. He also reported that there could be a space of about 5 mm between the anterior ethmoidal artery and skull base.
According to Gotwal who extensively studied the course of anterior ethmoidal artery by viewing coronal CT scans of nose and sinuses found that the presence of a notch in the medial wall of orbit indicates the probable site of antrior ethmoidal foramen. He also suggested that the presence of focal funneling in the olfactory fossa could indicate the probable position of anterior ethmoidal artery.
Coronal CT showing a dimple in the medial wall of orbit indicating the probable position of anterior ethmoidal artery canal.
Coronal CT showing anterior ethmoidal artery coursing close to skull base
Coronal CT paranasal sinuses showing the probable location of anterior ethmoidal artery close to the roof of frontal sinus and skull base.
Coronal CT showing anterior ethmoidal canal during its course through the anterior ethmoidal cells
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