**3. Anatomy of the deep arm veins**

The anatomy of the deep veins of the upper extremity is shown schematically in Figure 1. The two brachiocephalic veins (also known as innominate veins) join to form the superior vena cava. Each brachiocephalic vein is formed by the confluence of the subclavian with the internal jugular vein. The subclavian vein arises from (usually more than one) axillary veins, which originate from the usually paired brachial veins. The main superficial arm veins, the cephalic and basilic veins, usually drain into the sublcavian and axillary vein, respectively. The other, smaller arm veins (radial and ulnar veins) are only rarely involved in clinically significant deep vein thrombosis. Superficial thrombophlebitis may involve the cephalic and basilic veins as well as the smaller superficial veins in the cubital region or forearm. Of note, the subclavian vein passes between the clavicle and the first rib ventral of the anterior scalenus muscle, where it may be compressed in some patients especially during strenuous arm exercise. In some patients, this space is further limited by muscular hypertophy (anterior scalenus or suclavius muscle) or bone abnormalities (clavicle, first rib, cervical rib), resulting in venous thoracic outlet syndrome (Illig & Doyle, 2010).

Fig. 1. Schematic view of the principal neck and arm veins.

third of patients with deep arm vein thrombosis will have primary thrombosis, i.e. idiopathic and effort-related thrombosis (Paget-von Schroetter syndrome). The remaining two thirds of patients will have secondary upper extremity thrombosis with exogenous (e.g. central venous catheters) or endogenous (e.g. cancer) risk factors. In intensive care patients as well as in patients suffering from malignant disease with central venous catheters, rates of asymptomatic thrombosis as high as 30% to over 60% have been reported (Timsit et al*.*, 1998; Van Rooden et al*.*, 2005). There appears to be an increase in upper extremity deep vein thrombosis in the last decades, which may reflect the increasing use of central venous catheters (S. Mustafa et al*.*, 2003; Czihal & Hoffmann,

The anatomy of the deep veins of the upper extremity is shown schematically in Figure 1. The two brachiocephalic veins (also known as innominate veins) join to form the superior vena cava. Each brachiocephalic vein is formed by the confluence of the subclavian with the internal jugular vein. The subclavian vein arises from (usually more than one) axillary veins, which originate from the usually paired brachial veins. The main superficial arm veins, the cephalic and basilic veins, usually drain into the sublcavian and axillary vein, respectively. The other, smaller arm veins (radial and ulnar veins) are only rarely involved in clinically significant deep vein thrombosis. Superficial thrombophlebitis may involve the cephalic and basilic veins as well as the smaller superficial veins in the cubital region or forearm. Of note, the subclavian vein passes between the clavicle and the first rib ventral of the anterior scalenus muscle, where it may be compressed in some patients especially during strenuous arm exercise. In some patients, this space is further limited by muscular hypertophy (anterior scalenus or suclavius muscle) or bone abnormalities (clavicle, first rib, cervical rib),

**Superior vena cava**

**Brachiocephalic vein**

2011), improved diagnostic methods, or both.

resulting in venous thoracic outlet syndrome (Illig & Doyle, 2010).

Fig. 1. Schematic view of the principal neck and arm veins.

**3. Anatomy of the deep arm veins** 

I**nternal jugular vein**

**Subclavian vein**

**Cephalic vein**

**Axillar vein**

**Brachial vein**
