Publication:

Relationship of anterior ethmoidal artery with skull base and posterior wall of frontal sinus: a computed tomography-based retrospective clinical study

Background The close proximity of anterior ethmoidal artery (AEA) to the skull base predisposes the artery to injury during ESS. This study aims to decipher the course of AEA and determine its relationship with the skull base and posterior wall of frontal sinus with the help of computed tomography.

Methods The vertical distance between the skull base and the anterior ethmoidal foramen in the coronal scans, the horizontal distance between posterior wall of frontal sinus ostium and AEA in the sagittal scans and the number of intervening cells between posterior wall of frontal sinus and AEA were analyzed in CT scans of 75 patients over a period of six months.

Results The AEA was lying 2.5-5 cm below the level of skull base in majority of the CT scans analyzed. Most of the CT scans studied demonstrated only a single intervening cell between posterior wall of frontal sinus ostium and AEA on either side. In our study there was a strong positive relationship between the AEA- skull base distance and between the AEA-posterior wall of frontal sinus distance on either side.

Conclusions Distance between the AEA and skull base is variable, but a freely running AEA within a bony canal was a more common variant than skull base variant in our study. AEA-skull base distance and AEA-frontal sinus distance on right side correlated with values of left side indicating symmetrical course of the AEA on either side in an individual.