Nasal Branch of the Anterior Ethmoidal Artery and Cribroethmoidal Groove: New Frontal Sinus Landmarks

Objective: Expanded frontal sinusotomies (Draf IIb/c-III) are essential surgical procedures for managing complex frontal sinus pathologies. However, traditional anatomical landmarks may be difficult to identify, particularly in tumor or revision cases. This manuscript investigates the nasal branch of the anterior ethmoidal artery (NbAEA) and the cribroethmoidal groove (CrEGr) as reliable and consistent landmarks for endoscopic frontal sinusotomies. Methods: This study included anatomical dissections (medio-lateral approach) on three fresh cadavers (six sides) focused on the region anterior to the first olfactory phylum, namely the cribo-frontal area. Additionally, a retrospective clinical case series of patients that underwent centripetal dissection with a medio-lateral approach to the frontal sinus was performed. Identification of NbAEA, CrEGr, and the first olfactory phylum, along with surgical outcomes and complications, was analyzed. Results: The NbAEA and CrEGr were identified in all dissected sides and were located anterior to the first olfactory phylum. Considering the 19 enrolled patients, 13/19 (68.4%) were treated with a bilateral centripetal dissection and Draf III procedure (26 sides); whereas 6/19 patients (31.6%) underwent a unilateral approach with a Draf IIb/c procedure. The NbAEA and CrEGr were identified in all cases (100%) and in only 9/19 cases (47.7%) the first olfactory phylum was additionally exposed, reinforcing the role of these new anatomical landmarks. No perioperative complications were recorded. Conclusions: This study supports the clinical significance of NbAEA and CrEGr as reliable anatomical landmarks, and their identification in 100% of cases reinforces their practical applicability in surgical approaches to the frontal sinus. Level of Evidence: Level 4.