The physiological disturbances produced by an Arteriovenous Fistula are well known.
In an extremity, the abnormally increased blood flow through a fistula results in! engorgement and dilatation of the veins, with increased local temperature.
Distal to the fistula,` however, varying degrees of ischemia may be caused and ´there may be overgrowth of the affected extremity, especially in childhood. This is presumably due to the diminished arterial flow caused by the reduced arterial pressure distal to the shunt.
When an arterio-venous fistula occurs between renal vessels, the hemodynamic changes may produce "Gold blatt kidney" on the affected side due to renal ischemia with resulting systemic hypertension.
In cases of an arteriovenous fistula in the lung, unsaturated blood may bypass the lung through the fistulous opening and return to the Lt. side of the heart and result in systemic cyanosis.
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