Peripheral arteriovenous fistula. Detection by contrast echocardiography

A method for detecting peripheral arteriovenous fistulas using contrast echocardiography is described. The detection of intracardiac and intrapulmonary shunts by this technique has previously been documented. After injection of indocyanine green dye into the blood stream, a dense cloud of echoes can be detected downstream as well as at the injection site. This echo-producing effect is completely lost on a single transit through a capillary bed. Thus detection of resultant echoes in the systemic venous circuit after systemic arterial injection of dye would indicate the presence of an abnormal arteriovenous communication. We have recently tested this hypothesis for the confirmation of left-to-right shunts in two patients who had suspected traumatic lower extremity arteriovenous fistulas. After injection of indocyanine green dye through a small-gauge needle into the femoral artery, a dense cloud of contrast echoes appeared in the right ventricle, which indicated the presence of arteriovenous shunting. This procedure is safe and easily performed and represents a new and relatively noninvasive technique for the detection of peripheral arteriovenous fistulas.