Advanced CT imaging demonstrating the bulla lamella and the basal lamella of the middle turbinate as endoscopic landmarks for the anterior ethmoid artery

Objective: Our objective is to show how the use of Computer Tomography (CT) multiplanar displays (MPR) and 3D Stereoscopic Imaging (3DSI), can provide precise anatomical landmarks to identify the location of the Anterior Ethmoid Artery (AEA) during endoscopic sinus surgery (FESS). Materials and Methods: The study comprised 48 patients, representing 96 nasal cavity/sinus sides. The anterior ethmoid foramen was the landmark that defined the entry of the AEA into the ethmoid on CT MPR and 3DSI, and anatomic relationships closely related to to the AEA were recorded. Results: The anterior ethmoidal foramen (AEF) was associated with the bulla lamella (BL) in 46.9% of cases, and the basal lamella of the middle turbinate (BLMT) in 31.6%. In 7.1% of cases, the AEF was associated with both lamellae. Similarly, at the AES, the AEF was associated with the BL and BLMT in 72.5% and 46.9% of cases, respectively. In 29.6%, the AEA was associated with both lamellae. In 48%, the AEF and AES were at or in the bone of the ethmoidal roof/ skull base. In 48%, the AEA, the AEF, and the AES were in the same coronal plane, indicating a straight horizontal course across the ethmoid. In the remaining samples, the AES was anterior to the AEF, indicating an oblique course of the AEA. Conclusion: This study demonstrates that 3DSI imaging provides improved localization of the AEA, and establishes recognizable anatomic landmarks for endoscopically guided surgery, thus, preventing inadvertent complications.