The veins

• The internal thoracic artery; and • The costocervical trunk, which divides into the superior intercostal and the deep cervical arteries.

The subclavian artery becomes the axillary artery at the outer border of the first rib. The axillary artery lies w i th the brachial plexus and the axillary vein. It supplies six arteries to the chest wall and the shoulder (SALSA): • The superior thoracic artery; • The acromiothoracic trunk; • The lateral thoracic artery; • The subscapular artery; and • The anterior and posterior circumflex humeral arteries.

The brachial artery begins at the lower border of teres major. Its branches are: • The profunda brachii artery (which arises medially); • The nutrient artery to the humerus; • The muscular branches; and • The branches to the elbow joint.

At the level of the radial head (but sometimes much more proximally) the brachial artery divides into the radial and ulnar arteries. The radial artery passes on the lateral side of the forearm to the wrist, where it gives a branch to the superficial palmar arch and then passes via the floor of the anatomical snuffbox to the dorsum of the hand. It passes between the first and second metacarpals to form the deep palmar arch.

The ulnar artery is larger and deeper than the radial artery. It gives rise to the common interosseus artery, which in turn divides into the anterior and posterior interosseus arteries, the latter passing over the top of the interosseus membrane to supply the muscles of the dorsum of the forearm. Close to the wrist the ulnar artery becomes superficial and, having crossed the wrist, becomes the superficial palmar arch and sends a branch to the deep palmar arch.

Radiological features of the arterial supply of the upper limb

Arteriography (see Fig. 1.42) Arteriography of the aorta or of its coronary or other branches can be achieved via the arteries of the upper limb. Percutaneous puncture of the axillary artery carries the risks of brachial plexus damage, either directly or by haematoma formation. The brachial artery, although smaller, is easier to puncture because of its superficial location over a bone. Damage to the nearby median nerve may occur, as may embolism distally to the radial or ulnar arteries.

Arteriography of the upper limb is achieved usually via the aortic arch by a femoral approach. The vessels and their branches already described are seen. Direct puncture of the subclavian, axillary or brachial arteries is occasionally used, particularly for interventional work such as embolization of arteriovenous malformations of the forearm or hand. THE VEINS OF THE UPPER LIMB (Fig. 7.17) Superficial and deep veins drain blood from the upper limb. The superficial veins commence in the hand, where smaller veins unite to form three veins - the cephalic and basilic veins from the dorsum and the median vein from the palm.

The cephalic vein ascends from the radial side of the dorsum of the hand and winds around the forearm towards the elbow. Here it gives the median cubital vein to join the basilic vein and it then continues on the lateral side of the biceps muscle. At the shoulder it passes medially, pierces the clavipectoral fascia to become deep and joins the axillary vein.

The basilic vein has a similar course on the medial side of the forearm and elbow. At midhumeral level it passes deeply and joins the brachial vein to become the axillary vein.

The median vein of the forearm passes from the palm along the volar aspect of the forearm to join either the basilic or the cephalic veins at the elbow.

The deep veins of the upper limb are usually paired venae comitantes, which accompany the arteries. The axillary veins are usually double, whereas the subclavian vein is usually single.

Radiological features of the veins of the upper limb

Venography Venography of the upper limb is achieved by injection of the superficial veins of the dorsum of the hand. To visualize the deep veins, films are taken w i th and without inflation of a tourniquet on the arm above the elbow.

Superior venacavography is achieved by simultaneous injection of veins of both arms. If thrombosis of the superior vena cava (SVC) is suspected and extension into the axillary veins is a possibility, then cannulation of the basilic veins is preferable to cannulation of the cephalic veins, as the latter bypass the proximal part of the axillary veins.

Intravenous injection of contrast or radionuclides in dynamic studies Blood flow in the cephalic vein may be held up at the site where it passes through the clavipectoral fascia. This makes this vein less suitable than the basilic vein for intravenous injection of contrast or radionuclides in dynamic studies.