Applied anatomy of occipital artery

to study origin, diameter, course, branches and distribution of occipital artery, and provide anatomical data for extracranial-intracranicial arterial anastomisis and occipital-vertebral arterial anastomosis. occipital arteries and third segment of the vertebral arteries were dissected and observed on the 16 cadavers. The occipital artery arises from the posterior wall of external carotid artery at inferior border of posterior belly of the digastric muscle. Occipital artery runs obliquely upward and backward parallel to the lower border of posterior belly of the digastric muscle, often covered by this muscle. Then the occipital artery runs in occipital groove on medial side of mastoid process. The site from which occipital artery perforates deep fascia is located at (17.31±3.14) mm below superior nuchal line, and (24.57±5.27) mm lateral to milline. The average external diameter of occipital artery are (1.93±0.23) mm at original part, (1.72±0.24) mm at the site of piercing deep fascia. Branching patterns of occipital artery in scalp are main stem type, two and three branch type. The third part of the vertebral artery is in U shape and around posterior part of the superior articular facet of atlas. Its external diameter is (3.17±0.59) mm. Some occipital arteries give their branches to deep muscle of nape and anatomose with descending branches of occipital arteries and cervical deep arteries.[Conclusion] The present study presented some anatomical data about occipital artery and third segment of vertebral artery, which would advantage occipital-vertebral artery anastomosis and occipital-middle cerebral artery or occipital-posterior inferior cerebellar artery anastomosis to treat vertebrobasilar ischemia.