Upper vena cava

Upper vena cava – the short thin-walled vein with a diameter from 20 to 25 mm located in a front mediastinum. Its length on average varies from five to eight centimeters. The upper vena cava belongs to veins of a big circle of blood circulation and is formed by merge of two (left and right) brachiocephalic veins. It collects a venous blood from the head, upper parts of a thorax, a neck and hands and falls into the right auricle. The only inflow of an upper vena cava is the unpaired vein. Unlike many other veins, this vessel has no valves.

The upper vena cava is directed down and enters a pericardium cavity at the level of the second edge, and falls into the right auricle slightly below.

The upper vena cava is surrounded:

• At the left – an aorta (the ascending part);
• On the right – a mediastinal pleura;
• Ahead – a thymus gland (thymus) and the right lung (the mediastinal part covered with a pleura);
• Behind – a root of the right lung (a front surface).

System of an upper vena cava

All vessels which are logging in an upper vena cava are located rather close to heart, and during relaxation appear as a result of prisasyvayushchy operation of its cameras. Also affects them during respiratory movements a thorax. At the expense of these factors in system of an upper vena cava rather strong negative pressure is created.

The main inflows of an upper vena cava are valveless brachiocephalic veins. In them also always very low pressure therefore there is a risk of hit of air at their wound.

The system of an upper vena cava is made by veins:

• Areas of a neck and head;
• Chest wall, and also some veins of walls of a stomach;
• Upper shoulder girdle and upper extremities.

Venous blood from a chest wall comes to inflow of an upper vena cava – an unpaired vein which incorporates blood from intercostal veins. At an unpaired vein two valves located in its mouths.

The outside jugular vein is located at the level of a mandible corner under an auricle. In this vein blood from the fabrics and bodies located in the head and a neck gathers. Veins fall into an outside jugular vein back ear, occipital, nadlopatochny and front jugular.

The internal jugular vein originates about a jugular foramen of a skull. This vein together with a vagus nerve and the general carotid artery forms a bunch of vessels and nerves of a neck, and also includes brain veins, meningeal, eye and diploichesky veins.

The vertebral veniplexes which are logging in a hollow upper vein are subdivided on internal (passing in the spinal channel) and outside (located on the surface of bodies of vertebrae).

Syndrome of a prelum of an upper vena cava

The syndrome of a prelum of an upper vena cava which is shown as disturbance of its passability can develop for several reasons:

• When progressing development of oncological diseases. At a disease of lung cancer and lymphoma lymph nodes in close proximity to which there passes the hollow upper vein often are surprised. Also metastasises of a breast cancer, myagkotkany sarcomas, a melanoma can lead to disturbance of passability;
• Against the background of cardiovascular insufficiency;
• At development of a retrosternal craw against the background of pathology of a thyroid gland;
• When progressing some infectious diseases, such as syphilis, tuberculosis and гистиоплазмоз;
• In the presence of iatrogenic factors;
• At an idiopathic fibrous mediastinitis.

The syndrome of a prelum of an upper vena cava depending on the reasons which caused it can gradually progress or develop quickly enough. It is possible to carry to the main symptoms of development of this syndrome:

• Puffiness of the person;
• Cough;
• Convulsive syndrome;
• Headache;
• Nausea;
• Dizziness;
• Dysphagy;
• Change of features;
• Drowsiness;
• Asthma;
• Faints;
• Thorax pains;
• Swelling of veins of a thorax, and in certain cases – a neck and upper extremities;
• Cyanosis and plethora of upper parts of a thorax and person.

For diagnosis of a syndrome of a prelum of an upper vena cava the X-ray analysis allowing to reveal the pathological center, and also to define borders and extent of its distribution is, as a rule, carried out. Besides, in certain cases carry out:

• Computer tomography – for obtaining more exact data on an arrangement of bodies of a mediastinum;
• Flebografiya – for assessment of extent of the center of disturbance and carrying out differential diagnosis between vascular and extravasated defeats.

After the conducted researches taking into account the speed of progressing of pathological process the issue of performing drug treatment, himio-or radiation therapy or operation is resolved.

In cases when thrombosis is the reason of changes of a vein, carry out thrombolytic therapy with the subsequent purpose of anticoagulative drugs (for example, heparin sodium or therapeutic doses of warfarin).