ABSTRACT
Anterior ethmoidal artery [AEA] has a great clinical and surgical importance. It is a particularly important landmark for the fovea ethmoidalis and the base of the anterior cranial fossa. It is a possible sight of traumatic or intraoperative bleeding. Accurate localization of the anterior ethmoidal canal [AEC] and anterior ethmoidal artery [AEA] both radiologically and surgically and their relation to nasal lamellas and skull base in order to avoid the serious complications that might happen after violation of the canal or the artery. 50 patients diagnosed to have chronic rhinosinusitis [CRS] with or without sinonasal polyposis were selected. All the cases were subjected to: a] preoperative computerized tomography. b] operative intervension in the form of endoscopic sinus surgery [ESS], with dissection of the roof of the ethmoid sinuses for indentification of the anterior ethmoidal canal [AEC]. Radiological evaluation was done by axial, helical thin cuts and reconstructed saggital views, while assessment during surgery was encountered after direct endoscopic visualisation, using palpation with a probe and simple ruler measurements. Twelve patients had ESS performed on one side and 38 patients ESS on both sides. Thereby, a total of 88 AEC identifications were performed. In all dissections the AEC and AEA were successfully identified surgically and radiologically. On comparing surgical and radiological localization of the AEC in relation to the lamellas, it was found that the location of the AEC was the same in 86 dissections, while not in 2 dissections. AEC was positioned inside the skull base without bony defects in 82 dissections, and in 6 dissections, 2mm below the skull base, connected to it by a mesentry. Endoscopic localization of the AEC during surgery and the results of CT imaging were comparable. It was found that the AEA, the anterior turbinate axilla and the superomedial edge of the nostril were in a straight line. This finding was extremely helpful in the endoscopic search for the AEA