Specifics of the hemodynamics in hemodialysis patients with hand ischemia

Background. Successful hemodialysis is impossible without an effective vascular access. However, the average duration of its normal functioning is 2.5-3.0 years that is associated with complications, one of them being steal syndrome of the hand. Aim: to examine the hemodynamic parameters in the permanent vascular access and forearm arteries in chronic hemodialysis patients with ischemic steal syndrome of the hand. Methods. Duplex ultrasound was performed in 550 patients, 517 of which (94.0%) had an arteriovenous fistula, 33 (6.0%) had an arteriovenous graft. The inflow artery, anastomotic zone, outflow vein and arteries distal to the anastomotic zone were assessed during ultrasound examination; linear and volumetric speed indicators, peripheral resistance indices were measured. Results. Steal syndrome was detected in 2.7% of cases. The main causes are the inflow artery alterations due to diabetes and atherosclerosis that lead to insufficient growth of the blood flow through the artery (20.0%); substantial anastomosis diameter that causes a vein dilation and significant increase in the access flow (13.3%); insufficient blood flow through the ulnar, anterior interosseous arteries and the absence of collateral branches not compensating for the retrograde blood flow in the radial artery distal to anastomosis (40.0%); microcirculatory dysfunction of the hand and alterations of the regulation mechanisms of the resistive vessels tone (26.7%). Conclusion. Dynamic ultrasound examination of the vascular access can detect adverse changes in the hemodynamics and avoid severe ischemic complications. The main contribution to the steal syndrome development belongs to the condition of the forearm arteries not participating in the fistula formation and the hand microvasculature.