Aortocaval fistula: an easily missed diagnosis

Four cases of rupture of an abdominal aortic aneurysm into the inferior vena cava are presented. Clinical diagnosis may be difficult because characteristic symptoms are not always present. It is important to recognize the symptoms of an aortocaval fistula as it is usually rapidly fatal. Recognition must lead to immediate surgical intervention. Special attention must be paid to prevent the serious complications inherent in this syndrome such as copious venous bleeding. Preoperatively, strict monitoring of intravenous transfusion is essential. During the operation care in handling the aneurysm is necessary to avoid pulmonary embolism. Surgical closure of the fistula is easy from within the aneurysm.