外頚動脈・中硬膜動脈—脳血管内治療に必要な外頚動脈の知識，特に中硬膜動脈と後頭動脈を中心に

External Carotid Artery:Essential Knowledge of the External Carotid Artery Required for Neuroendovascular Surgery, with a Focus on the Middle Meningeal Artery and Occipital Artery

Point

・脳血管内治療において外頚動脈は軽視されがちであるが，実際は内頚動脈や椎骨動脈との吻合が豊富であり，その理解は必須である．

・中硬膜動脈はpetrosal branchと顔面神経，anterior（frontal）branchと眼動脈など，重要構造物と関連をもつ．

・後頭動脈はpharyngo-occipital systemで説明されるように，上行咽頭動脈や椎骨動脈などと密接な関連，吻合をもつ．

　The perfusion territory of the external carotid artery is often underestimated; however, this blood vessel forms abundant “dangerous anastomoses” with the internal carotid and vertebral arteries. An understanding of these vascular anastomoses is crucial to ensure safe cerebrovascular interventions. There are several important aspects of the middle meningeal artery that should be considered, including anastomoses with the anterior（frontal）branch and ophthalmic artery through the sphenoidal artery（recurrent meningeal artery）and meningolacrimal artery. Additionally, the blood supply to the facial nerve via branches of the petrosal branch, such as the superior tympanic artery, and the formation of the facial arcade by the superior tympanic and stylomastoid arteries, which often originate from the posterior auricular artery, is significant. The occipital artery demonstrates rich anastomoses with vessels, such as the ascending pharyngeal and vertebral arteries, forming what is known as the pharyngo-occipital system.