Nasal branch of the anterior ethmoid artery: a consistent landmark for a midline approach to the frontal sinus

Background Frontal sinusotomy can be challenging when significant scarring or distorted anatomy is present. Identifying a reliable anatomic structure, when traditional landmarks or navigation are absent, may assist the surgeon in revision and complicated frontal sinusotomies via a midline approach. We aimed to characterize the anatomic relationship of the nasal branch of the anterior ethmoid artery (NBAEA) to the frontal infundibulum, specifically the first olfactory fili, posterior frontal infundibulum, and anterior cribriform plate. Methods Dissection of the NBAEA was carried out in 11 cadaveric heads, resulting in a total of 21 dissections (1 aplastic frontal). Mean with standard deviation and a range were established for 7 relative measurements. Results The total length of NBAEA cleft when present (mean 2.43 mm), the anterior edge of NBAEA cleft to anterior infundibulum coronal plane (mean 1.71 mm), the posterior edge of NBAEA cleft to posterior infundibulum coronal plane (mean 3.33 mm), the posterior edge of NBAEA cleft to 1st olfactory fili (mean 2.86 mm), and the first olfactory fili to posterior infundibulum coronal plane (mean 0.48 mm) were consistent measurements supporting the use of the NBAEA as a consistent anatomical landmark for the correct surgical coronal trajectory into the midline frontal sinus. Conclusion The NBAEA is a consistent anatomic landmark with minimal intercadaveric and intracadaveric variation. It can be used reliably as a “sentinel artery” notifying the surgeon when one is approaching the first olfactory fili, to determine the correct trajectory into the midline frontal sinus.