Endoscopic Study of Ethmoidal Canals in Cadavers, Including a Histological Analysis of Their Contents

Abstract Introduction The advent of the endoscope has enabled the use of the endonasal approach for a variety of diseases. Studying the ethmoidal canals is important for surgeries of the paranasal sinuses and the anterior base of the skull. Objective To investigate the ethmoidal canals and evaluate their structure, the presence of vessels and nerves, their location, and to perform an anatomopathological study of their contents. Methods We evaluated 20 cadavers (20 left and 20 right nasal cavities) through endoscopic dissection of the anterior base of the skull and exposure of the medial periorbita and dura mater; then, the ethmoidal canals were located and measured in relation to the anterior wall of the sphenoid sinus and between the ethmoidal canals, followed by removal of their content for histological analysis. Results Vessels were present in 75% of the left anterior ethmoidal canals, 70% of the left posterior ethmoidal canals, 75% of the left middle ethmoidal canals, 85% of the right anterior ethmoid canals, and 64.5% of the right posterior ethmoid canals; 50% of the right middle ethmoidal canals contained one vessel. Conclusion The ethmoidal canal does not necessarily contain an ethmoidal artery. Studies with a larger sample should be performed to quantify the correct proportion of arteries and ethmoidal canals.

In Vivo Computed Tomography Direct Volume Rendering of the Anterior Ethmoidal Artery: A Descriptive Anatomical Study

Abstract Introduction The clinical relevance of the anatomy and variations of the anterior ethmoidal artery (AEA) is outstanding, considering its role as a landmark in endoscopic surgery, its importance in the therapy of epistaxis, and the high risks related to iatrogenic injuries. Objective To provide an anatomical description of the course and relationships of the AEA, based on direct computed-tomography (CT)-based 3D volume rendering. Methods Direct volume rendering was performed on 18 subjects who underwent (CT) with contrast medium for suspected cerebral aneurism. Results The topographical location of 36 AEAs was assessed as shown: 10 dehiscent (27.8%), 20 intracanal (55.5%), 6 incomplete canals (16.7%). Distances from important topographic landmarks are reported. Conclusion This work demonstrates that direct 3D volume rendering is a valid imaging technique for a detailed description of the anterior ethmoidal artery thus representing a useful tool for head pre-operatory assessments.