An arteriovenous fistula may be congenital (usually affecting smaller vessels) or acquired as a result of trauma (eg, a bullet or stab wound) or erosion of an arterial aneurysm into an adjacent vein. In patients with end-stage renal disease requiring hemodialysis Hemodialysis In hemodialysis, a patient’s blood is pumped into a dialyzer containing 2 fluid compartments configured as bundles of hollow fiber capillary tubes or as parallel, sandwiched sheets of semipermeable... read more , an arteriovenous fistula is created surgically to provide vascular access for the procedure.
The fistula may cause symptoms and signs of
Arterial insufficiency Peripheral Arterial Disease Peripheral arterial disease (PAD) is atherosclerosis of the extremities (virtually always lower) causing ischemia. Mild PAD may be asymptomatic or cause intermittent claudication; severe PAD... read more (eg, ulceration due to reduced arterial flow or ischemia)
Chronic venous insufficiency Chronic Venous Insufficiency and Postphlebitic Syndrome Chronic venous insufficiency is impaired venous return, sometimes causing lower extremity discomfort, edema, and skin changes. Postphlebitic (postthrombotic) syndrome is symptomatic chronic... read more due to high-pressure arterial flow in the affected veins (eg, peripheral edema, varicose veins, stasis pigmentation)
Emboli may pass from the venous to the arterial circulation (and cause ulceration when they lodge in distal vessels), although pressure differences make this unlikely. If the fistula is near the surface, a mass can be felt, and the affected area is usually swollen and warm with distended, often pulsating superficial veins.
A thrill can be palpated over the fistula, and a continuous loud, to-and-fro (machinery) murmur with accentuation during systole can be heard during auscultation.
Rarely, if a significant portion of cardiac output is diverted through the fistula to the right heart, high-output heart failure Heart Failure (HF) Heart failure (HF) is a syndrome of ventricular dysfunction. Left ventricular (LV) failure causes shortness of breath and fatigue, and right ventricular (RV) failure causes peripheral and abdominal... read more develops.
Diagnosis of Arteriovenous Fistula
Fistulas are diagnosed clinically based on presence of thrill, murmur, and other signs. Doppler ultrasonography is the best confirmatory test.
Treatment of Arteriovenous Fistula
Sometimes percutaneous occlusion techniques
Congenital fistulas need no treatment unless significant complications developing. When necessary, percutaneous vascular techniques can be used to place coils or plugs into the vessels to occlude the fistula. Treatment is seldom completely successful, but complications are often controlled.
Acquired fistulas usually have a single large connection and can be effectively treated by surgery.