• Active tobacco use, typically moderate to heavy.
  
• Severe digital ischemia without evidence of internal organ involvement.
  
• Angiography reveals segmental involvement of medium-sized arteries, with abrupt vascular cut-offs and corkscrew collaterals.
  
• The major vessel involvement occurs at the levels of the ankle and wrist.

In Buerger disease, also called thromboangiitis obliterans, the classic patient is a young male smoker. The mean age of onset is approximately 40 years, but the disease can occur in teenagers as well as in the elderly. Although the patients described initially were men, the disease may afflict women as well, probably in direct proportion to the number of women in any particular society who smoke. The precise mechanism underlying the relationship between Buerger disease and cigarette smoking is unknown; autoimmune reactions to constituents of tobacco have been postulated. Cases may present several years after the start of smoking, but Buerger disease does not occur in the absence of ongoing tobacco exposure.

There are four keys to the diagnosis of Buerger disease: (1) Recognition of clinical findings compatible with that condition; namely, digital ischemia without involvement of other organs. (2) Identification of the typical pattern of vascular involvement by angiography. (3) Exclusion of diseases that may mimic Buerger disease (Table 41–1). (4) Confirmation that the major risk factor, ongoing tobacco exposure, is present.

Because of difficulty in accessing medium-sized vessels for biopsy, the diagnosis is rarely confirmed by biopsy. The exceptions to this rule are superficial thrombophlebitis, which seldom comes to medical attention, and amputation specimens, by which time medical attention is (at least in some senses) too late. When biopsy is possible, acute Buerger disease is characterized by a highly inflammatory thrombus, composed of a variety of cell types: lymphocytes, neutrophils, giant cells, and occasional microabscesses. Inflammation is typically more intense within the clot itself than within the walls of affected blood vessels. Fibrinoid necrosis, a hallmark of most systemic vasculitides, is absent in Buerger disease.

Symptoms and Signs

Extremities

A major hallmark of Buerger disease is its confinement to the extremities. The initial symptoms may be nonspecific pains in the calf, foot, or toes. The progression of thrombosis and vasculitis can lead to horrific pain in the digits and limbs and ultimately to gangrene and tissue loss, through either autoamputation or elective amputation. For unknown reasons, however, other vascular beds (eg, the cardiac, pulmonary, renal, and mesenteric vasculature) are nearly always spared in Buerger disease.

Although Buerger disease has a predilection for the feet and toes, the hands and fingers may also be affected prominently. More than 60% of patients have abnormal Allen tests, indicating compromise of circulation to the hand; many demonstrate obliterations of the radial or ulnar artery pulses on physical examination. In contrast to atherosclerosis, which is a disease of the proximal vasculature, Buerger disease is characterized by inflammation and thrombosis of medium-sized, distal blood vessels (both arteries and veins), most intense at the levels of the ankles and wrists.

Skin

The earliest lesion may be a superficial thrombophlebitis. This complaint is often disregarded by the patient or misdiagnosed as deep varicosities. Histologic examination of these lesions reveals an acute thrombophlebitis with marked perivascular infiltration. This herald lesion is then followed by progressive occlusion of the deeper veins and arteries, leading the patient to seek medical attention. Patients with Buerger disease may have splinter hemorrhages, arousing suspicions of infective endocarditis. Most cutaneous features of disease are those of a process involving the medium-sized vessels exclusively (purpura, for example, a manifestation of small-vessel disease, is absent).