Figure 90-1. Manifestations of upper extremity ischemia. Splinter hemorraghes in the nails arising from a proximal embolic source (A). Gangrene affecting the tip of the third finger (B). Advanced, severe gangrene in the radial artery distribution secondary to complications related to an arterial line (C).
Ergotamine-induced vasospasm can create ischemia of the hands and the feet. Historically, several epidemics occurred in Europe during the Middle Ages caused by the ingestion of rye contaminated by alkaloid-producing fungi. After a miraculous cure that was believed to have occurred thanks to the relics of Saint Anthony the Great, the Hospital Brothers of St. Anthony’s order was founded and the term “St. Anthony’s Fire” became popular. Today, most cases of ergotism are due to antimigraine drugs or recreational substance abuse.5
Connective tissue disorders are a common cause of upper extremity ischemia. Lesions typically affect the distal vasculature and are more common in scleroderma, rheumatoid arthritis, CREST syndrome, mixed connective tissue disorder, and lupus. Raynaud phenomenon is often the manifestation in early stages whereas digital gangrene occurs in late stages of the disease.
Peet et al. first coined the term thoracic outlet syndrome (TOS) in 1956 to encompass a group of signs and symptoms related to compression of the brachial plexus, subclavian artery, or subclavian vein as they pass from the thorax into the axilla. Only in 1% of all cases of TOS, the artery, is the structure compressed. Although TOS is often asymptomatic, patients may present with a range of signs and symptoms, from fatigue or pain in the affected arm upon exertion and Raynaud phenomenon to critical ischemia of the upper extremity because of emboli arising from the chronically injured artery or from a mural thrombus in a poststenotic aneurysm sac. The artery is compressed as it passes through the thorax into the axilla through the narrow gap formed by the clavicle superiorly, the first rib inferiorly and the subclaveous muscle anteriorly and superiorly, as well as the scalene muscles posteriorly (Fig. 90-4). Bony anomalies, such as cervical rib or an abnormal first thoracic rib, are sometimes present. Aneurysms can also form because of repetitive trauma in branches of the subclavian artery. These aneurysms can be the source of emboli that manifest as ischemic lesions in the hands.6 Pectoralis minor syndrome is a distinct condition caused by compression of the subclavian artery by the pectoralis minor as it travels cephalad to insert in the coracoid process (Fig. 90-4).
Ischemia caused by abnormalities in the axillary, brachial, radial, and ulnar arteries is often the result of iatrogenic etiologies. One of the most common causes of ischemia seen in our practice is due to hemodialysis access. Hand ischemia due to steal phenomenon is common and ischemia as a result of intra-arterial catheters also occurs frequently.
Occupational injuries to the arteries of the hand result in thenar or hypothenar hammer syndrome. The ulnar artery is vulnerable to injury at the hypothenar eminence, just distal to the wrist where the ulnar artery passes through Guyon canal bound by the pisiform and hamate bones. Here, the ulnar artery is cushioned only by skin, subcutaneous tissue, and the thin palmaris brevis muscle. Repetitive use of the palm of the hand as a “hammer” compresses the unprotected ulnar artery against the nearby hook of the hammate bone. Both aneurysm formation and occlusive disease can occur (Fig. 90-5). 7
HISTORY AND PHYSICAL EXAMINATION
Given the frequent association of upper extremity ischemia with systemic and occupational disorders, a thorough medical and social history is mandatory. Interrogation should include inquiring about tobacco and drug use. Antimigraine medications, HIV antivirals, and most commonly recreational drugs, like cocaine and other alkaloids, can cause ergotism. Occupational history is of particular importance when evaluating upper extremity vascular issues. TOS occurs in athletes who are required to perform repetitive overhead shoulder motion (swimmers, baseball pitchers, weight lifters, etc.). Repetitive trauma to the palmar eminences (thenar and hypothenar) is typically observed in manual laborers (machinists, carpenters, and construction workers) but has also been described in athletes, musicians, and even computer workers who use their hands repetitively causing injury to the palms.
Figure 90-2. Selective left-hand angiogram in a patient with chronic renal insufficiency. There is severe, diffuse disease affecting a heavily calcified ulnar artery (arrow). In addition, there is lack of contrast opacification in several of the digital arteries.
Figure 90-3. Aortogram in the right oblique projection of a patient with Takayasu arteritis. Long-segment right common carotid stenosis (small arrows) leading into a normal appearing carotid bifurcation. Segmental occlusion of the right subclavian artery (block arrow) just distal to the origin of the right vertebral. There is distal reconstitution via a large collateral. There is also an aneurysm (star) of a previous bypass in the left subclavian artery.
Figure 90-4. Compressive zones of the thoracic outlet. The subclavian structures can be compressed at the costoclavicular space, the scalene triangle, or distally at the border of the pectoralis minor muscle.
The presence of atherosclerotic disease in the heart or other vascular beds should also be investigated. History of connective tissue disorders or their symptoms (dysphagia, arthritis, telangiectasia, and other skin abnormalities) cannot be obviated during the evaluation of upper extremity ischemia. Changes in the appearance of the skin of the hands suggestive of Raynaud’s should be explicitly investigated.
Figure 90-5. Ulnar artery aneurysm resulting from repetitive trauma in a construction worker.
It is necessary to obtain clear documentation of any prior intervention in the arm (hemodialysis access, biopsies, brachial or axillary access for cardiac catheterizations) or episodes of trauma (clavicular or rib fractures, humeral, shoulder, or elbow injuries) (Fig. 90-6).
A complete physical examination needs to include a systemic evaluation looking for signs of atherosclerotic, inflammatory, or autoimmune disease. A meticulous inspection, auscultation, and palpation of both sides of the neck, periclavicular areas, shoulders, and the entire arms and hands is done in the resting, neutral position, and also while abducting the arm. A bruit or a thrill in the periclavicular area would suggest the presence of stenosis or poststenotic dilation arising from TOS and a prominent pulse should point to an aneurysm in the subclavian artery. Comparison between the two upper extremities is of crucial importance since bilaterality often points to a systemic disorder. A careful hand examination includes inspecting for splinter hemorrhages under the beds of the nails, skin evidence of embolism or gangrene, changes in the color of the skin related to vasospasm and signs of trauma in the hand. Careful palpation of the radial, ulnar, snuffbox, and even digital pulses is done. Digital pressure is then applied to the ulnar and radial arteries in the wrist. After the patient opens and closes his or her hand, pressure is removed from one of the wrist arteries and inspection of the color of the hand and palpation of the distal pulses is repeated (Allen test). The test is normal if the entire hand recovers its color and capillary refill. If a portion of the hand fails to normalize, suspicion arises that the palmar vascular collateral circulation (palmar arch) is incomplete. Finally, blood pressure measurements in both arms are obtained and compared (brachiobrachial index).
Figure 90-6. Old clavicular fracture treated with a metallic prosthesis. Notice the luminal abnormality in the subclavian artery as it crosses the clavicle. This lesion was caused by periosteal scarring and caused distal embolism in the hand.