Aorto-inferior vena caval fistula of neoplastic origin. Hemodynamic and coronary blood flow studies.

Abstract

A case report of a 51-year-old man is presented, who spontaneously developed an aorto-vena caval fistula in the region of a mesenchymal tumor involving both the abdominal aorta and vena cava. The disease was manifested clinically by rapidly progressive and massive leg swelling, prominent abdominal and leg veins, a machinery murmur over the abdomen and in the flanks, and a pulsatile abdominal mass, with signs of cardiac enlargement and a high output state. The fistula was demonstrated preoperatively by translunmbar aortography and closed surgically by resection of the tumor en masse, with a part of the vena caval wall and the distal aorta and proximal common iliac arteries. Vascular continuity was restored by lateral suture of the vena cava and by insertion of a bifurcation graft bridging the defect in the aorta and iliac arteries. The patient has been relieved of all clinical manifestations of the fistula to date, 1 year after operation. Preoperative hemodynamic studies revealed certain alterations characteristic of systemic arteriovenous fistula, including increased pulse pressure, high cardiac output and stroke volume, reduced systemic vascular resistance and arteriovenons oxygen difference, and increased plasnma and circulating blood volumes. Some degree of cardiac failure appeared to be present. Coronary arteriovenous oxygen difference was normal, indicating that the observed increase in coronary blood flow closely paralleled the augmented energy requirement of the heart as reflected by the ventricular oxygen uptake. Reversion to normal of the observed changes in systemic hemodynamics, coronary blood flow, and myocardial metabolism was demonstrated 2 weeks postoperatively.