Analysis of the Correlation of the Lamina Papyracea-to-Midline Distance with the Location of Anterior Ethmoidal Artery and Keros Classification

The aim of the study was to investigate the relations between anatomical structures that are susceptible to inadvertent injuries during the surgery using preoperative computed tomography (CT) scans. 153 CT scans were reviewed and the distance from the lamina papyracea (LP) to the midline and the distance of the anterior ethmoidal artery (AEA) to the skull base were measured bilaterally. Also, the depth of olfactory fossa was measured and categorized using the Keros classification. The measurements were analyzed to determine whether LP-to-midline distance was correlated with the distance between the AEA and the skull base and Keros classification. Additionally, correlation of Keros classification with the distance from the AEA to the skull base was investigated. In a total of 306 measurements, 26 (%8.49) were classified as Keros type I, 200 (65.35%) as Keros type II and 80 (25.14%) as Keros type III. Statistically, LP-to-midline distances on the right and left sides were significantly associated with the distance from the AEA to the skull base on the same side (R:p < 0.001, L:p = 0.01) and the Keros classification on the same side (R:p < 0.001, L:p = 0.004). Also, a significant association was found between the Keros classification and the distance from the AEA to the skull base (R:p < 0.001, L:p = 0.02). The locations of anatomical structures are defined in relation to each other during the development of maxillofacial bones. CT scans should be examined and anatomical structures and relations among them reviewed very carefully before ESS. Otherwise, some accidental injuries may arise during the surgery while trying to avoid complications.