Bilateral subclavian vein thrombosis in a patient with acquired immunodeficiency syndrome.

Bilateral subclavian vein thrombi developed, in the presence of a Groshong catheter, in a patient with the acquired immunodeficiency syndrome (AIDS) and disseminated cytomegalovirus infection. Thrombosis is an uncommon complication of AIDS, and bilateral subclavian thrombi are rare. Although localized, unilateral thrombi occur in patients with indwelling central venous catheters, unexpectedly extensive bilateral clot formation is seen to develop in patients with human immunodeficiency virus infection. Potentially predisposing factors for thrombosis in AIDS include central venous catheterization, malignancy, elevated anticardiolipin antibodies, alteration of vascular endothelial cell function reflected in low free protein S levels, and enhanced endothelial procoagulant activity related to cytomegalovirus. Anecdotal data strongly suggest that cytomegalovirus enhances the risk for thrombosis, but studies are needed to confirm the association. Physicians should be aware of the enhanced risk for extensive thrombi in AIDS, especially in patients with disseminated cytomegalovirus infection.