The brachiocephalic artery, brachiocephalic trunk, or innominate artery is an artery of the mediastinum that supplies blood to the right arm, head, and neck.
It is the first branch of the aortic arch. Soon after it emerges, the brachiocephalic artery divides into the right common carotid artery and the right subclavian artery.
There is no brachiocephalic artery for the left side of the body. The left common carotid artery and the left subclavian artery come directly off the aortic arch. Despite this, there are two brachiocephalic veins.
Structure
The brachiocephalic artery arises on a level with the upper border of the second right costal cartilage from the start of the aortic arch
- anterior - left brachiocephalic vein and thymus
- posterior - trachea
- right - superior vena cava, right brachiocephalic vein, and pleura
- left - left common carotid artery and thymus
The thymus typically sits atop the brachiocephalic artery, and it separates the artery from the posterior surface of the manubrium of sternum.
Function
The brachiocephalic artery sends blood from the heart to the right arm, head, and neck. Oxygenated blood from the aortic trunk is taken through the brachiocephalic artery into the right subclavian artery, which transports blood to the right arm, and into the right common carotid artery, where blood is transported to the head and neck.
Clinical significance
Innominate artery aneurysms represent 3% of all arterial aneurysms. Because there is a risk of thromboembolic complications and spontaneous rupture, surgical repair is usually recommended early on after discovery. Innominate artery aneurysms often present with signs of innominate artery compression syndrome and have a very high risk of rupture. The majority of IA aneurysms are due to atherosclerosis. Other causes include syphilis, tuberculosis, Kawasaki's disease, Takayasu's arteritis, Behçet's disease, connective tissue disease, and angiosarcoma.
Several abnormalities of the brachiocephalic artery have been reported. A retroesophageal innominate artery is a rare congenital anomaly. Also, aberrant innominate artery crossing anterior to the trachea just below the thyroid isthmus was reported. Anterior neck surgeries such as bronchoscopies and mediastinoscopies are common and safe procedure, since operating around the trachea, no major vessel is encountered in the surgical field. However, when this type of abnormality is encountered, even minor trauma can lead to mass bleeding culminating in death. Aberrant innominate artery can cause incomplete vascular ring. It does not completely encircle the trachea and esophagus, but some compress either the trachea or esophagus. Anomalous innominate artery originates later from the transverse arch and then crosses the trachea causing anterior tracheal compression.
Additional images
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File:Slide15e.JPG|Brachiocephalic artery
File:Slide3eeee.JPG|Brachiocephalic trunk
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See also
- Hip bone (Innominate bone)