Phlegmasia cerulea dolens is a condition in which total or near-total occlusion of the venous outflow tract produces massive edema of the extremity and a characteristic violaceous discoloration of the skin. This extensive venous obstruction ultimately leads to ischemic necrosis. Although the mechanism for this remains obscure, a derangement of capillary function would seem to be implicated. More specifically, a marked decrease in the arteriovenous pressure gradient caused by an absolute increase in the venous pressure would seem to inhibit the arterial inflow critically, while the resultant damage to the capillary walls would interfere with the transfer of oxygen to the tissues. Major occlusion of veins as the cause of gangrene was first described by Fabricus Hildanus in 1593.1 The entity received little attention in the medical literature until 1937, when Fontaine and de Sousa-Pereira2 reported that gangrene resulted in the hind limb of a dog after total