Abstract:ObjectiveTo study the endoscopic anatomy of internal carotid artery (ICA) in order to provide references for the safety of endoscopic skull base surgery.MethodsEndoscopic and general dissections and relative data measurement were performed in the ICA region of 8 adult cadaveric heads (16 sides). The relationships among the ICA and its surrounding structures were observed and related anatomic parameters were measured.ResultsAnterior bend of ICA was located at the superiorposterior aspect of lateral sphenoid wall, slanting inward at about 60° angle with optic nerve impression outboard the sellar base. The horizontal section of ICA was roughly on the same line with the prolongation of tympanic segment of facial nerve with cranial nerves Ⅲ, Ⅳ and Ⅴ adjacent to its front part. Its posterior was adjacent to cochlea and emerged from foramen lacerum.ConclusionsWith close relationships to the structures of ear and nose, each segment of ICA can be located with closely related structures. Comprehensive understandings of the surrounding structures as well as their relationships are of great significance for the safety of endoscopic skull base surgery.