Abstract
The vascular access (VA) necessary for chronic hemodialysis can be assessed using VA ultrasonography. We discuss the assessment of stenosis and occlusion of arteriovenous fistula (AVF), arteriovenous graft (AVG), and subcutaneously fixed superficial artery by VA ultrasonography. B-mode can be used to assess the shunt vessel course and properties of the involved area in VA stenosis and occlusion. In addition to morphological assessment, functional assessment of AVF and AVG is possible with pulsed Doppler by using flow volume (BA-FV) in 1 minute calculated based on the flow pattern of the brachial artery and the resistance index (RI), and measuring these is very useful as an indicator in the functional monitoring of VA in all cases. Anastomotic stricture and venous (including hardening of venous valve) and stent site stenosis occur in AVF. In cases with occlusion, it is often caused by a thrombus, but it is important to identify the origin of the stenosis that is causing thrombus formation. Morphological assessment of AVG using VA ultrasonography consists of assessment of stenosis and occlusion occurring in the graft and assessment of stenosis that tends to occur at the venous outflow tract. Stenosis can occur at the cannulation site of a subcutaneously fixed superficial artery. Occlusion can also occur due to a thrombus or other cause. Subcutaneously fixed superficial artery is often complicated by damage to the arterial wall due to repeated punctures, and regular follow-up observation with VA ultrasonography is important.
