Although much of the focus of venous disorders concentrates on the lower extremities, pathologic conditions such as deep venous thrombosis (DVT) also affect the upper extremities with significant frequency. Certain venous disorders, such as Paget-Schroetter syndrome (PSS), arise specifically because of anatomic relationships seen only in the upper limbs. The increasing usage of central venous catheters is also linked to the increased prevalence of upper extremity venous pathology. Advancements in noninvasive diagnosis and treatment have expanded the therapeutic options for upper extremity venous disorders.
UPPER EXTREMITY VENOUS ANATOMY
The similarities in arterial development of the upper and lower extremities are also present in the venous system. The upper limb has both a superficial and deep system of veins. These both drain into a single outflow tract, the axillary vein. The dorsal aspect of the upper extremity receives venous drainage primarily via the cephalic vein laterally and the basilic vein medially. The median cubital vein joins both of these veins at the antecubital fossa and is a frequent site of blood draws. The cephalic vein continues along the surface of the biceps muscle in the upper arm and then pierces the clavipectoral fascia to join the axillary vein. The basilic vein travels along the medial aspect of the arm and pierces the fascia of the upper arm to join the deep brachial vein to become the axillary vein. The deep veins of the upper extremity begin with the palmar interosseous veins and continue as paired communicating veins traveling alongside the radial and ulnar arteries. These radial and ulnar veins join with a third group of deep veins, the forearm interosseous veins. These then form the paired brachial veins, which continue as the axillary, subclavian, and innominate (brachiocephalic) veins centrally.
The upper central venous system consists of both internal jugular veins and subclavian veins. These unite behind the sternoclavicular joints to form the right and left innominate veins. Both innominate veins then join to form the superior vena cava (SVC). The right and left innominate veins are asymmetric, the left being 6 cm in length compared with 2.5 cm on the right. The SVC descends along the right side of the ascending aorta to enter the right atrium at the level of the third costal cartilage. The azygous vein joins the SVC posteriorly just before it enters the pericardium.
Variations in the venous anatomy of the upper extremity are frequent but are rarely of clinical significance. Unlike the lower extremities, venous drainage of the upper limb is largely dependent on cardiac function. This is secondary to the lack of a muscle pump, lessening the importance of venous valves. In addition, blood flow in the arm veins may increase with respiration and decrease with expiration because there is no high-pressure area corresponding to the abdomen between the thorax and the arm. Because of the human erect posture, pathologic venous conditions ...