Pathology of Upper Extremity Arterial Disease



Pathology of Upper Extremity Arterial Disease



Alexander D. Shephard and Joseph Karam


Upper extremity arterial disease is relatively uncommon. Unlike lower extremity disease, where the cause is predominantly atherosclerotic and the patients older, upper extremity arterial pathology is far more diverse and often affects younger persons (Box 1). Treatment modalities for these pathologies vary considerably, making a correct diagnosis imperative. Most patients complain of ischemic symptoms, though patients with aneurysmal disease occasionally experience symptoms related to compression of surrounding structures. As a result of the rich collateral network of the upper extremity and its relatively low workload compared to the lower extremity, patients complain of exercise-induced symptoms (fatigue, numbness, and/or paresthesias) less commonly than those with lower extremity disease.



BOX 1   Upper Extremity Arterial Pathology









Vasospasm


Vasospasm is by far the most common cause of upper extremity ischemia; it is estimated to affect up to 10% of the population, with female patients predominating. Vasoconstriction of the small arteries of the hand is a natural response to sympathetic stimuli, cold, pain, and emotional stress. With pathologic vasospasm, digital arteries are overly sensitive to the offending stimulus, and prolonged vasoconstriction leads to local ischemia. Vasospastic episodes are classically intermittent, with relatively normal or compensated flow between attacks.


Most patients present with some degree of digital ischemia on exposure to cold, tobacco, or emotional stress as manifested by blanching of the fingertips with accompanying numbness and coolness. The classic triphasic color changes as described by Raynaud (pallor to cyanosis to reactive hyperemia when normal flow returns) are seen infrequently. Symptoms, regardless of degree, usually abate slowly with removal of the offending stimulus. Vasospasm of large arteries is very rare, but it can be caused by ergot-containing medications used to treat migraine disease. Vasopressor-induced digital ischemia is an increasingly recognized entity in the modern critical care unit, where tissue loss is a common outcome. Prompt recognition and weaning of causative pressor agents is the best treatment. Cocaine abuse can cause large and small artery vasospasm.



Intrinsic Arterial Disease


Atherosclerosis


The most common cause of intrinsic arterial disease affecting the upper extremity is atherosclerosis. Although any segment of the upper extremity vasculature can be affected, the proximal brachiocephalic arteries are most often involved, particularly the origin of the left subclavian. Multiple lesions affecting the origins of all three arteries occur in up to 25%, and almost 50% have associated carotid bifurcation disease. In contrast to lower extremity atherosclerosis, most such lesions are asymptomatic even when severe.


Symptoms, when they occur, can include both central nervous system and upper extremity ischemia (from either arterial embolization or hypoperfusion). Though reversed flow in the ipsilateral vertebral artery in the presence of hemodynamically significant subclavian disease is often present, classic subclavian steal symptoms including dizziness, vertigo, and visual disturbances with use of the affected arm are relatively rare. Ischemic symptoms in the involved extremity (i.e., effort-induced fatigue, paresthesias, and numbness) can occur but usually suggest multilevel disease. Digital gangrene and ischemia are very rare with brachiocephalic disease and are usually related to atheroembolism from an ulcerated lesion. The most common manifestation of brachiocephalic atherosclerosis in the asymptomatic elderly patient is a blood pressure discrepancy between the two arms.


Radiation arteritis (or radiation-accelerated atherosclerosis) can affect the upper extremities of patients undergoing therapy for a variety of malignancies, most commonly lymphoma, lung cancer, and breast cancer. Fortunately, such lesions are increasingly rare with modern radiation therapy techniques. The axillosubclavian segment is most commonly involved. Azotemic arteriopathy is a particularly virulent form of atherosclerosis that affects the distal extremity vasculature (forearm, palmar, and digital arteries) of patients with diabetes and end-stage renal disease. Diffuse calcification of the digital and palmar arteries often leads to critical limb ischemia.



Inflammatory Diseases


A number of inflammatory diseases can affect the upper extremity arterial vasculature ranging from the large brachiocephalic vessels to the smallest digital arteries. Takayasu disease and giant cell (or temporal) arteritis (GCA) are large-vessel vasculitides that involve the proximal vasculature. Both diseases can be associated with an initial inflammatory stage (fever, arthralgias, myalgias, elevated erythrocyte sedimentation rate) before presenting with ischemic symptoms from characteristic smooth, tapering stenoses resulting from inflammation involving all three layers of the vessel wall. Takayasu disease typically involves the proximal and mid portions of the carotid and subclavian arteries and occurs in young (20–40 years) women. Upper extremity effort fatigue occurs in up to 60%, and approximately 30% experience carotidynia. In contrast, GCA, a far more common vasculitis, usually affects the extracranial branches of the carotid artery in older (>50 years) women. Among patients with GCA, 10% to 15% have involvement of the upper extremity arteries, most commonly the distal subclavian, axillary, and proximal brachial arteries. Such patients can experience asymmetric blood pressures or arm effort fatigue.


Buerger’s disease or thromboangiitis obliterans is a segmental, inflammatory, obliterative disease of the medium and small arteries of the extremities seen in young heavy smokers. In the upper extremities it usually affects the forearm and palmar/digital arteries, sparing the more proximal vessels. Although previously it was thought to be exclusively a disease of men, in modern series 10% to 20% of affected patients are female. Diagnosis is based on a history of recent or current heavy smoking; distal limb ischemia (lower extremity more commonly involved than upper) in the absence of other atherosclerotic risk factors, embolic disease, thrombophilia, or connective tissue disorder; and onset before age 50 years. Angiographic findings that suggest Buerger’s disease include segmental occlusions of distal extremity arteries (diseased segments interspersed with normal-appearing vessels) with classic, but not pathognomonic, corkscrew collaterals and normal nonatherosclerotic proximal arteries.

Stay updated, free articles. Join our Telegram channel

Aug 25, 2016 | Posted by in CARDIOLOGY | Comments Off on Pathology of Upper Extremity Arterial Disease

Full access? Get Clinical Tree

Get Clinical Tree app for offline access