[Acquired systemic arteriovenous fistulas. Experience of 33 cases]

We analyzed 33 cases of Acquired Systemic Arteriovenous Fistulas (FAVSA) seen in the INC-ICH between 1945 and 1981. The most frequent causes were traumatic (gunshot and knife wounds) and iatrogenic (surgery). The most affected vessels were femoral, carotid, axillary and subclavian. The FAVSA produced a hyperkinetic hemodynamic syndrome of high output that frequently resulted in fistular cardiopathy. Fistular cardiopathy and heart failure became evident from 4 days to 31 years after the initial insult and was related to the magnitude of the arteriovenous shunt. The latter depended on the distensibility of the communicating ring (the development of perifistular fibrosis did not allow dilatation of the fistular opening). Heart failure was a result of the magnitude of the shunt, even when the patient was young with a healthy heart. A detailed traumatic or surgical history was extremely important in the diagnosis. Relevant physical signs included: bounding pulses, a wide pulse pressure, the presence of a continuous murmur and thrill, a positive Nicoladoni-Branham's sign with a decrease in the heart rate and an increase in systemic blood pressure when the FAVSA was compressed. The existence of the condition became suspicious when heart failure appeared otherwise unexplained by an obvious cardiac lesion. Other important signs included the development of distal venous insufficiency and the presence of a palpable pulsatile mass. Fistular cardiopathy was observed in 60% of the cases studied, although the ECG was normal in 33%; 73% had cardiomegaly which improved with correction of the FAVSA. The treatment is necessarily surgical and required the appropriate technique.