The brachiocephalic artery (or brachiocephalic trunk or innominate artery) is an

artery An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...

of the mediastinum that supplies blood to the right arm and the head and neck. It is the first branch of the

aortic arch The aortic arch, arch of the aorta, or transverse aortic arch () is the part of the aorta between the ascending and descending aorta. The arch travels backward, so that it ultimately runs to the left of the trachea. Structure The aorta begins ...

. 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, and the left subclavian artery, come directly off the aortic arch. However, there are two

brachiocephalic vein The left and right brachiocephalic veins (previously called innominate veins) are major veins in the upper chest, formed by the union of each corresponding internal jugular vein and subclavian vein. This is at the level of the sternoclavicular ...

Structure

The brachiocephalic artery arises, on a level with the upper border of the second right costal cartilage, from the start of the

, on a plane anterior to the origin of the left carotid artery. It ascends obliquely upward, backward, and to the right to the level of the upper border of the right sternoclavicular articulation, where it divides into the right common carotid artery and right subclavian arteries. The artery then crosses the

trachea The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air- breathing animals with lungs. The trachea extends from t ...

in front of it obliquely from the left to the right, roughly at the middle of the trachea or the level of the ninth tracheal cartilage.

Relations

Brachiocephalic artery has relation with: * ''anterior'' - left

and thymus * ''posterior'' - trachea * ''right'' - superior vena cava, right brachiocephalic vein, and

pleura The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls. The inner pleura, called the visceral pleura, covers the surface of each lung and dips b ...

* ''left'' - left common carotid artery and thymus

Thymus The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or '' T cells'' mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders ...

typically sits atop the brachiocephalic artery, and separates the artery from the posterior surface of the manubrium of sternum.

Branches

The thyroid ima artery ascends in front of the trachea to the lower part of the

thyroid The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The ...

, which it supplies.

Variation

The innominate artery usually gives off no branches, but occasionally a small branch, the thyroid ima artery, arises from it. Other times, it gives off a thymic or bronchial branch. Thyroid ima artery varies greatly in size, and appears to compensate for deficiency or absence of one of the other thyroid vessels. It occasionally arises from the aorta, the right common carotid, the subclavian or the

internal mammary In human anatomy, the internal thoracic artery (ITA), previously commonly known as the internal mammary artery (a name still common among surgeons), is an artery that supplies the anterior chest wall and the breasts. It is a paired artery, with one ...

Development

Aortic sac is the embryological precursor of proximal portion of the aortic arch. It is chronologically the first portion of the aorta to form, and appears as a dilation superior to the truncus arteriosus. Between the two horns of aortic sac, right horn gives rise to the brachiocephalic artery. Then the right horn fuses with the right-sided third and fourth aortic arches, which give rise to the right common carotid artery and the proximal right subclavian artery respectively. Eventually, brachiocephalic artery is derived from

ventral aorta The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes o ...

, same as

ascending aorta The ascending aorta (AAo) is a portion of the aorta commencing at the upper part of the base of the left ventricle, on a level with the lower border of the third costal cartilage behind the left half of the sternum. Structure It passes obliqu ...

. Left horn forms proximal ascending portion of aorta.

Function

Brachiocephalic artery brings blood from heart to right arm, head, and neck.

Clinical significance

Innominate artery aneurysms represents 3% of all arterial aneurysms. Since there is the risk of thromboembolic complications and spontaneous rupture, surgical repair is usually recommended on an early period. Innominate artery aneurysms can 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 Syphilis () is a sexually transmitted infection caused by the bacterium '' Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms of syphilis vary depending in which of the four stages it presents (primary, secondary, latent, a ...

tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, ...

Kawasaki's disease Kawasaki disease is a syndrome of unknown cause that results in a fever and mainly affects children under 5 years of age. It is a form of vasculitis, where blood vessels become inflamed throughout the body. The fever typically lasts for more ...

, Takayasu's arteritis, Behçet's disease, connective tissue disease, and angiosarcoma. Tracheo-innominate artery fistula (TIF) is a surgical emergency with high mortality rates. Reported incidence is 0.1%-1.0% after tracheostomy. TIF is usually fatal once it bleeds. For the successful management of TIF, treatment should be initiated immediately with the special considerations kept in mind. Several abnormalities of 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

and

esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...

, 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

File:Slide15e.JPG, Brachiocephalic artery File:Slide3eeee.JPG, Brachiocephalic trunk

References

External links

* {{Authority control Arteries of the thorax