There is a paucity of new, substantive information concerning the presentation or histopathology of thromboangiitis obliterans since the initial observations of Leo Buerger 85 years ago. In fact, due to a poor understanding of the disease and a lack of rigid diagnostic criteria, the condition became mired in controversy for many years and its very existence was questioned by influential authors writing in prestigious medical journals. This controversy prompted a critical re-examination of the diagnosis and clinical presentation of the disease. Clearly, most reports prior to the 1960s mistakenly included many patients with premature atherosclerosis, as well as unsuspected autoimmune diseases or hypercoagulable states. Abundant evidence supports the existence of Buerger's disease as a discrete clinical and pathophysiologic entity. It is clearly not variant atherosclerosis. Segmental thrombotic occlusions of medium and small-sized extremity arteries characterize the disease. The high frequency of upper extremity involvement differs distinctly from the pattern of atherosclerotic occlusive disease. Buerger's disease is frequently associated with superficial migratory phlebitis and Raynaud's syndrome. Although it most frequently occurs in young male smokers, it also definitely occurs in women. True Buerger's disease has declined in prevalence in North America over the last 30 years, however, eastern Europe, the Middle East, and the Orient continue to report large numbers of patients. The histopathology of the acute Buerger's lesion is diagnostic. A hypercellular intraluminal thrombus with inflammation of the vessel wall and giant cell foci are visible in distal extremity arteries and veins. The elastic lamina of the vascular wall remains intact, however, an important point of distinction from immune arteritis. The aetiology of Buerger's disease is unknown. A recent report from Japan used radioisotope studies to document an apparent breakdown in the microcirculation very early in the course of Buerger's disease. The cause of this microvascular disruption is unclear. There is an undeniable association of Buerger's disease with tobacco use, and disease progression is clearly associated with continued smoking. At present, however, tobacco appears to be only a permissive factor. Antibodies to purified human types I and III collagen have been reported in patients with Buerger's disease, and other immunologic abnormalities of cellular and humoral responses detected, but it is uncertain whether these findings represent primary aetiologic factors, or secondary phenomena occurring in response to vascular wall inflammation. Tobacco abstinence remains the cornerstone to medical management. No medical therapy is of proven benefit, although antiplatelet therapy appears reasonable, and calcium channel blockers are of occasional benefit in patients with severe Raynaud's symptoms. Ischaemic upper extremity ulcers are treated with a conservative regimen to attain healing and preserve maximal digital length. Pentoxifylline may be of benefit in the treatment of ischaemic digital ulcers. Thoracic sympathectomy is of no lasting benefit and cannot be recommended. In contrast to upper extremity lesions, for which less than 5-8% of patients progress to finger amputation and major limb amputation is virtually never required, the prognosis for lower extremity Buerger's disease is much more somber. Approximately 20% of patients will require toe or forefoot amputation during the course of their diases; 20 of patients reported in the literature required major lower extremity amputation below or above the knee. This latter figure is over 30% in my personal experience of patients meeting rigid diagnostic criteria. Neither lumbar sympathectomy nor arterial reconstruction has significantly altered this natural history. In contrast to the risk of major lower extremity amputation, life expectancy in patients with Buerger's disease approaches that of the normal population. In summary, Buerger's disease is a discrete diagnostic entity which can be defined by typical clinical, histopathologic, epidemiologic, and natural history studies. Although a proposed immunologic basis for the disease holds promise, further research in well-defined patient populations meeting strict diagnostic criteria will be required. The development of effective therapy will probably occur only once the aetiology has been established.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine