Acute Spontaneous Aorto-Vena Caval Fistula

THE acute development of a spontaneous arteriovenous fistula between the abdominal aorta and the inferior vena cava produces a remarkable clinical picture. Most important among the clinical features of this condition is high output cardiac failure. In this connection it is well recognized that cardiac disturbances are more pronounced in cases with fistula of spontaneous origin than in those following trauma. This is because the onset in the spontaneous group is usually more rapid and the fistulous opening greater in size. In addition to the usual hemodynamic changes associated with systemic arteriovenous communications, abdominal aorto-vena caval fistulas of spontaneous origin present special clinical findings. The lower extremities may be enormously enlarged, cold, and cyanotic in association with suddenly increased venous pressure and decreased arterial perfusion. Oliguria and hepatomegaly with liver failure may result from increased venous pressure in visceral veins and decreased arterial perfusion. A loud toand-fro murmur is present