Purpose: To describe the anatomical variability of the ethmoidal arteries (EAs). To evaluate the reliability of cone beam computed tomography (CBCT) in preoperative assessment of EAs.
Methods: Fourteen cadaver heads underwent CBCT and endoscopic dissection. The following anatomical features were evaluated for anterior (AEA), middle (MEA), and posterior (PEA) EAs: presence, cranio-caudal position, antero-posterior position, and dehiscence of the bony canal. Accuracy of radiological assessment was calculated.
Results: AEA, MEA, and PEA were identified in 100, 28.6, and 100% of sides. They were caudal to the skull base in 60.7, 25, and 17.9%, respectively. CBCT showed a high accuracy in identifying these features. The antero-posterior position of EAs, which was highly variable, was correctly assessed by CBCT. A dehiscent bony canal of AEA, MEA, and PEA was found in 46.4, 12.5, and 28.6% of sides, respectively. Accuracy of CBCT in picking up this feature was poor but negative predictive value was high.
Conclusions: CBCT was adequate in identifying and localizing EAs. In addition, it can be used to exclude the presence of MEA and dehiscence of ethmoidal canals, whereas the accuracy in detecting these anatomic variants was low.
Keywords: Arteries; Cone beam computed tomography; Endoscopy; Ethmoid sinus; Transnasal endoscopic surgery.