Concurrence of symmetrical peripheral gangrene and venous limb gangrene following polytrauma: a case report.

BACKGROUND: Symmetrical peripheral gangrene is characterized as acral (distal extremity) ischemic limb injury affecting two or more extremities, without large vessel obstruction, typically in a symmetrical fashion. Risk factors include hypotension, disseminated intravascular coagulation, and acute ischemic hepatitis ("shock liver"). In contrast, venous limb gangrene is characterized by acral ischemic injury occurring in a limb with deep vein thrombosis. Both symmetrical peripheral gangrene and venous limb gangrene present as acral limb ischemic necrosis despite presence of arterial pulses. The coexistence of symmetrical peripheral gangrene and venous limb gangrene is rare, with potential to provide pathophysiological insights.

CASE PRESENTATION: A 42-year-old Chinese man presented with polytrauma (severe head injury, lung contusions, and right femur fracture). Emergency craniotomy and debridement of right thigh wound were performed on presentation. Intraoperative hypotension secondary to bleeding was complicated by transient need for vasopressors and acute liver enzyme elevation indicating shock liver. Beginning on postoperative day 5, he developed an acute platelet count fall (from 559 to 250 × 109 /L over 3 days) associated with left iliofemoral deep vein thrombosis that evolved to bilateral lower limb ischemic necrosis; ultimately, the extent of limb ischemic injury was greater in the left (requiring below-knee amputation) versus the right (transmetatarsal amputation). As the presence of deep vein thrombosis is a key feature known to localize microthrombosis and hence ischemic injury in venous limb gangrene, the concurrence of unilateral lower limb deep vein thrombosis in a typical clinical setting of symmetrical peripheral gangrene (hypotension, proximate shock liver, platelet count fall consistent with disseminated intravascular coagulation) helps to explain asymmetric limb injury - manifesting as a greater degree of ischemic necrosis and extent of amputation in the limb affected by deep vein thrombosis - in a patient whose clinical picture otherwise resembled symmetrical peripheral gangrene.

CONCLUSIONS: Concurrence of unilateral lower limb deep vein thrombosis in a typical clinical setting of symmetrical peripheral gangrene is a potential explanation for greater extent of acral ischemic injury in the limb affected by deep vein thrombosis.