Spontaneous Aorto-Venous Fistula: An Occult Diagnosis

Abstract

Intravenous rupture of abdominal aortic aneurysms are an uncommon occurrence. The classic syndrome of recent high output heart failure, pulsatile abdominal mass, continuous bruit, oliguria and regional venous hypertension should raise the suspicion of this diagnosis. Our experience of four cases are presented with two survivors. None of the four patients had preoperative aortograms. In only one patient was the diagnosis considered preoperatively. The others were variants in that one had the fistula occluded by thrombus, while the remaining two presented with clinical signs of ruptured aneurysm. The diagnosis, in the variants, was established intraoperatively when profuse venous bleeding ensued upon removing the clot from within the aneurysm. Our experi ence revealed that aorto-venous fistula is many times an occult diagnosis. Successful results depend upon prompt surgical intervention and high index of suspicion especially in cases of ruptured aneurysms.