Corpus: Subclavian vein
1. Definition
The subclavian vein is a large-lumen, paired vein at the upper thoracic aperture. It continues the axillary vein proximally.
2. Anatomy
2.1. Course
The subclavian vein emerges as an extension of the axillary vein at the lateral edge of the first rib. It runs across the cranial surface of this rib in the subclavian vein groove and thus passes behind the clavicle. It follows the subclavian artery but is separated from it by the tendon of the anterior scalene muscle. The subclavian vein is located in front of the anterior scalene muscle, while the subclavian artery runs behind the muscle. However, both vessels run in front of the middle scalene muscle.
After passing the anterior scalene muscle, the subclavian vein unites with the internal jugular vein behind the origin of the sternocleidomastoid muscle to form the brachiocephalic vein. The passage between the two neck muscles is sometimes referred to as the anterior scalene gap. The union of the two veins occurs at almost a 90-degree angle. This prominent spot is called the venous angle. Here, the thoracic duct opens on the left side of the body, and the right lymphatic duct opens on the right side.
2.2. Fixation
The subclavian vein is fixed to the periosteum of the clavicle by the clavipectoral fascia. This prevents the vessel from collapsing at negative pressure values in the right atrium, ensuring unobstructed blood return to the heart. The vessel lumen has a diameter between 10 and 20 mm.
2.3. Tributaries
3. Function
The subclavian vein drains blood from the upper extremity and the shoulder girdle, as well as blood from the head and neck area.
4. Clinic
The subclavian vein is used as possible access for a central venous catheter (CVC), the subclavian catheter. Acute thrombosis of the subclavian vein leads to the so-called Paget-von-Schroetter syndrome.