Subclavian artery
The structure of the subclavian artery
The subclavian artery is a paired organ consisting of the right and left subclavian arteries that supply blood to the arm and neck.
It is part of the systemic circulation and originates in the anterior mediastinum: the right subclavian artery comes from the brachiocephalic trunk, being its final branch, while the left one departs from the aortic arch. The left subclavian artery is longer than the right one: its intrathoracic part lies behind the brachiocephalic vein.
The direction of the subclavian artery in relation to the superior aperture of the chest lies laterally and upward, forming a slightly convex arch, enveloping the apex of the lung and the dome of the pleura.
Having reached the I rib, the subclavian artery enters the interscalene space, which is formed by the adjacent surfaces of the middle and anterior scalene muscles. In the indicated interval, there is the brachial plexus on it.
Having skirted the I rib, the subclavian artery goes under the collarbone and enters the axillary cavity, where it is already called the axillary artery.
There are three main sections of the left and right subclavian arteries:
- The first. It originates from the place of its formation to the entrance to the interstellar gap;
- Second. Starts in the interstellar space;
- Third. It starts at the exit from the interstellar space up to the entrance to the axillary cavity.
The following branches of the subclavian artery branch off from the first section:
Vertebral artery (a.vertebralis). Its path lies through the opening of the transverse process of the sixth cervical vertebra, rising up and entering the cranial cavity through the foramenmagnum - the large occipital foramen. Then it connects to the artery on the other side, forming together with it the basilar artery. The function of the vertebral artery is to supply blood to the spinal cord, muscles and the dura mater of the brain (its occipital lobes)
- The internal thoracic artery (a. Thoracicainterna) originates from the lower surface of the subclavian artery. It supplies blood with nutrients dissolved in it to the thyroid gland, main bronchi, diaphragm, sternum, chest, tissue of the anterior and upper mediastinum, as well as the chest and rectus abdominis muscle;
- Thyroid trunk (truncusthyrocervicalis). It departs from the inner edge of the scalene muscle, reaching a length of about 1.5 cm, and is subdivided into several branches that supply blood to the mucous membrane of the larynx, muscles of the neck and scapula.
The second section of the subclavian artery has only one branch: the costal-cervical trunk (truncuscostocervicalis). It originates on the posterior surface of the subclavian artery and is also divided into several branches: the deep cervical artery and the highest intercostal artery, from which the posterior (leading to the back muscles) and spinal branches branch off.
The branch of the third section of the subclavian artery is the transverse artery of the neck, which penetrates the brachial plexus and is subdivided into the superficial artery that supplies blood to the muscles of the back, the deep branch of the subclavian artery, and the dorsal artery of the scapula, which descends to the vastus muscle of the back, feeding it and the accompanying small muscles.
Subclavian artery lesions
Stenosis (narrowing of the lumen) is the main disease that affects the subclavian artery and its branches.
Stenoses are most often the result of atherosclerotic changes in the vessels or thrombosis. The causes of acquired (not congenital) stenosis of the subclavian artery are metabolic disorders in the body, inflammatory diseases and neoplasms.
Deposits on the walls of blood vessels that block the artery are lipid-based, being, in fact, derivatives of cholesterol.
Narrowing or stenosis of the subclavian artery, which reduces about 80% of the lumen of the vessel, leads to a decrease in volumetric blood flow, which leads to a very negative effect - a lack of nutrients and oxygen in the tissues that are supplied from the subclavian artery.
Arterial stenosis is often accompanied by the appearance of atherosclerotic plaques, which can completely block the flow of blood in the artery and increase the likelihood of ischemic stroke.
The main complaint of patients with stenosis of the subclavian artery: pain that increases with physical exertion, mainly on the side of the affected limb.
Treatment
The main methods of treatment for stenosis of the subclavian arteries are:
- X-ray endovascular stenting;
- Sleepy-subclavian shunting.
Carotid-subclavian bypass grafting is performed in patients with hypersthenic constitution (in whom the isolation of 1 section of the subclavian artery is associated with certain difficulties), as well as when stenosis is found in the second section of the subclavian artery.
Endovascular stenting has great advantages over open surgery: the operation is performed under local anesthesia through a small (2-3 mm) incision in the skin through a puncture hole.
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