The anatomic landmarks of ethmoidal arteries for the surgical approaches.

Knowledge of variations in the possible patterns of origins, courses, and distributions of the ethmoidal arteries are necessary for the diagnosis and important for the treatment of orbital disorders. Ethmoidal arteries are damaged in endonasal surgical interventions and in operations performed on the inner wall of the orbita.A description of the anatomic landmarks of the ethmoidal arteries and ethmoidal canals is presented, based on data from microdissection in 19 adult cadavers studied after injection of red-dyed latex into the arterial bed. In all subjects, each of ethmoidal arteries originated from ophthalmic artery. The anterior ethmoidal artery was observed in all specimens except for one case. The diameter of the artery thicker than the posterior ethmoidal artery was 0.92 +/- 0.2 mm on the right and 0.88 +/- 0.15 mm on the left. The branching of the anterior ethmoidal artery from the ophthalmic artery was determined in four different types. The diameter of the posterior ethmoidal artery was measured as 0.66 +/- 0.21 mm on the right and 0.63 +/- 0.19 mm on the left. The anterior ethmoidal canal was located between the second and third lamella in 29 of 38 cases. The mean distance between the limen nasi and anterior ethmoidal canal was 48.1 +/- 3.2 mm.The article confirms the well-known variability of the ethmoidal arteries and their topographic relation to the ethmoidal canals. Advances in surgical techniques, instrumentation, and regional arterial anatomy have resulted in functional operations of endoscopic sinus and orbital surgery with fewer complications.