Behçet Syndrome

Suspected autoimmune vasculitis with a genetic predisposition.

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Behçet Disease.

First described in 1937 by Dr. Helusi Behçet, a Turkish dermatologist.

Prevalence is highest in Turkey (80-320:100,000 in the general population) and Asia (2-30:100,000 in the general population), but patients from many parts of the world have been described. Male gender is predominant, especially in severe Behçet disease.

The majority of cases are sporadic, but familial forms are described. Behçet disease has been associated with HLA-B51 in 45 to 60% of cases, but the significance of this finding for the pathogenesis of Behçet disease is not established.

The cornerstone of the disease is a multisystemic vasculitis involving large and small vessels in various degrees. The underlying cause has not been defined, but an autoimmune pathogenesis, including an abnormal T-cell response to microbial antigens and cross-reaction toward body tissue, is suspected. Characteristically, skin pathergy is present or so-called positive, that is, an exaggerated reaction with formation of a papule or a pustula after minor trauma such as a needle puncture occurs. Although helpful (but not pathognomonic) for the diagnosis of Behçet disease, the majority of patients do not show this reaction.

No specific tests are available. The diagnosis relies on the clinical picture, and criteria for establishing the diagnosis have been published by the International Study Group for Behçet's Disease.

Recurrent oral and genital ulcerations and uveitis or retinal vasculitis are the characteristic findings in Behçet disease. Systemic manifestation may affect joints, gut, kidney, lung, and the cardiovascular system. Lung involvement presents with pulmonary infarction, hemoptysis, recurrent pneumonia, bronchiolitis obliterans, organizing pneumonia, and pleurisy. Cardiovascular manifestations include pulmonary artery aneurysms, intracardiac thrombus formation with right-sided predominance, and deep venous thrombosis of large veins. Aneurysmatic changes and thrombosis have been described in many other sites, including gut and brain. The clinical course of Behçet disease is characterized by alternating periods of disease activity and remission. Therapy mainly consists of antiinflammatory and/or immunosuppressive therapy, usually including steroids with or without cyclophosphamide. Because of the risks and benefits, the therapeutic approach to clot formation must be evaluated individually. Mortality is low and usually is the consequence of a thrombotic or hemorrhagic complication.

The possibility of systemic involvement has a significant impact on anesthesia. Chest radiography should be ordered to assess the extent of pulmonary manifestations. Cardiac and large-vessel involvement can be evaluated sonographically and should include the potential sites of central venous catheter insertion. Laboratory tests should include a complete blood count, coagulation profile, and routine chemistry. Drug history is important, especially to identify patients on anticoagulation or chronic steroid medication warranting perioperative stress prophylaxis.

Reported perioperative events include difficult tracheal intubation from oral scarring and two postoperative deaths from pulmonary hemorrhage in patients who underwent cardiac surgery for removal of an intracardiac thrombus. Intraoperative management should aim at reducing the risk of pulmonary hypertension and includes prevention of acidosis, hypercarbia, hypoxia, and pulmonary vasoconstrictors, and appropriate analgesia and depth of anesthesia. Pulmonary angiography is generally discouraged because of the increased risk of pulmonary vascular injury.

If pulmonary vascular involvement is present, the risk of increasing pulmonary artery pressure should be minimized. Most inhaled anesthetics have the potential to reduce hypoxic pulmonary vasoconstriction and thus might be beneficial, whereas the majority of intravenous anesthetic agents have no effect on hypoxic pulmonary vasoconstriction. α-Adrenergic agents should be used cautiously. If the gut is involved, the risk of gastrointestinal bleeding and bowel perforation is increased, especially in patients on steroid medication. In this case, antacid drugs should be given perioperatively. Glaucoma in patients with Behçet disease has been described, but seems to be rare. If present, drugs that potentially increase intraocular pressure should be avoided (e.g., succinylcholine, ketamine).

Behçet disease is distinguished from a number of other autoimmune vasculitic diseases such as the following:

Systemic Lupus Erythematosus (SLE): Chronic inflammatory, remitting, relapsing, multisystemic disorder of connective tissue, principally involving the skin, joints, kidneys, and serosal membranes.

Polyarteritis Nodosa (PAN): Autoimmune vasculitis affecting the small and medium-size arteries. Any organ can be affected; however, polyarteritis nodosa most often involves the skin, joints, kidneys, gastrointestinal tract, and peripheral nerves. Consequently, the clinical picture is highly variable.