Vascular steal

Abstract

Vascular steal is a hemodynamic derangement in which two vascular systems having different levels of pressure/resistance are interconnected by collateral vessels. Blood flow is shunted from the high to low pressure system. This can lead to reversal of blood flow in the distal arteries, a phenomenon referred to as vascular steal. Four vascular steal syndromes have been described in association with a dialysis vascular access-(1) subclavian-coronary artery steal syndrome, (2) subclavian-vertebral artery steal syndrome, (3) ischemic monomelic neuropathy, and (4) hemodialysis access-induced distal ischemia (HAIDI). HAIDI is the most common of these syndromes. Hand ischemia associated with the syndrome can be very serious and can lead to extensive tissue loss if not recognized early and treated. The pathophysiology of the syndrome is not simply the diversion of blood flow, but is the result of distal hypoperfusion. Reversal of flow within the artery distal to the AV access may be seen but is asymptomatic in most cases. Peripheral arterial occlusive disease is the primary risk factor for HAIDI. The syndrome occurs most often in association with an arteriovenous fistula associated with the brachial artery. Although clinical testing may be helpful, the diagnosis can generally be made based upon the patient's signs and symptoms. Most cases are mild and require only conservative management. Multiple treatment modalities have been described for the treatment of more serious cases of HAIDI. The ultimate treatment strategy should be based on severity of symptoms, the extent of patient co-morbidity the pathophysiology of the individual case with vascular access blood flow being of particular importance.