Summary: This study reports important variations in branches of the subclavian artery in a singular cadaver. The origin of the left vertebral artery was from the aortic arch. On the right side, no thyrocervical trunk was found. The subclavian artery, the main artery of the upper extremity, also gives off the branches which supply the neck region. The right subclavian arises from the brachiocephalic trunk, the left from the aortic arch. Because of this, the first part of the right and left subclavian arteries differs both in the origin and length. The branches of the subclavian artery are vertebral artery, internal thoracic artery, thyrocervical trunk, costocervical trunk and dorsal scapular artery. On the left, all branches except the dorsal scapular arise from the first part; on the right, the costocervical trunk usually springs from the second part").The vertebral artery is the first and largesi branch of the subclavian artery. Its extracranial part arises from the superoposterior aspect of the subclavian, usually enters the foramen of sixth cervical transverse processes, rarely the seventh, curves medially behind the lateral mass of the atlas and then enters the cranium via the foramen magnum. Its intracranial part joins its fellow to form the basillar artery at the lower pontine border.In this study, the variations of the branches oi the subclavian arteries in the cadaver of an eighty year-old man were described. On the left side, the vertebral artery arose directly from the aortic arch but on the right side, it was as usual. However on the right side, there was no thyrocervical trunk and the transverse cervical artery arose directly from the subclavian artery. It was also observed the righi suprascapular artery began from the internal thoracic artery.The variations of the subclavian artery and its branches have a great importance both in blood vessels surgery and in angiographic investigations.
SubjectsThis work is based on a dissection carried out in the Department of Anatomy in the Faculty of Medicine of the cukurova University in 1996-199'7 academic year. A dissection was made of neck region of 80-year-old male cadaver. After seeing variations, the dissection was completed by following the course of the subclavian arteries and their branches.
FindingsIn our case, the left vertebral artery originated from the superior aspect of the aortic arch between the left subclavian artery and the left common carotid artery instead of the left subclavian artery. It first ascended behind the carotid sheath for about 9.5 cm and then passed through the foramen of fifth cervical vertebra. Thyrocervical trunk arising from the superior aspect of the first part of the left subclavian artery gave off a common trunk . The transverse cervical artery and the suprascapular artery originated from this trunk near the medial border of the scalenus anterior muscle and crossed this muscle anteriorly (Fig. 1.a, b, c).