Subclavian vein
Vena subclavia
The subclavian vein continues the axillary vein from the lateral border of the first rib. It crosses the first rib in front of anterior scalene and joins the internal jugular vein behind the sternoclavicular joint to form the brachiocephalic vein.
Overview
The subclavian vein arches over the first rib and the dome of the pleura. It lies in front of anterior scalene, while the subclavian artery lies behind the muscle. The vein sits in a narrow space between the clavicle and the first rib (the costoclavicular space), close to the subclavius muscle. It has a valve about 2 cm before its end, and it receives the external jugular vein. At the venous angle it joins the internal jugular vein, and the major lymphatic ducts drain there.
Anatomy
- Tributaries
The external jugular vein, sometimes the anterior jugular vein, the dorsal scapular vein and, at the venous angle, the thoracic duct (left) or right lymphatic duct.
- Relations
In front: the clavicle and subclavius. Behind: anterior scalene and the phrenic nerve, which separate it from the subclavian artery. Below: the first rib. Behind and below: the dome of the pleura.
Function
- Drains the upper limb and part of the neck and chest wall.
- Receives lymph from the great lymphatic ducts at the venous angle.
Clinical significance
Subclavian central venous access
Subclavian (infraclavicular) lines are comfortable for patients and have a lower infection rate. However, they carry a higher risk of pneumothorax, and bleeding there cannot be stopped by direct pressure. Pacemaker leads are often inserted through this vein or through the axillary vein.
Effort thrombosis (Paget–Schroetter syndrome)
Repeated overhead arm movement, as in swimmers and weightlifters, can compress the vein in the costoclavicular space. The vein then thromboses, causing sudden swelling, blue discolouration and pain in the arm. This is the venous form of thoracic outlet syndrome.
Compiled from standard anatomy and physiology references — see the Cardiovascular System sources. For education only; not medical advice.