ARTERIOVENOUS FISTULA

abnormal direct opening between an artery and a vein; it sometimes results from accidental penetration wounds or from vascular disease, or it may be congenital in origin. As a result of the defect, the arterial pressure is passed to the venous side of the fistula, and the pressure in the vein in the side of the fistula away from the heart increases, causing distension. Affected persons complain of aching pain in or beyond the area of the injury, and the legs are usually puffy and frequently show distended veins. When there is an arteriovenous fistula, the pulse in the vein is diminished by direct compression of the supplying artery, resulting in a continuous murmur that may help in diagnosing and locating the fistula. By surgical repair normal flow can usually be reestablished.