[Duplex sonography of dialysis shunts. Noninvasive evaluation of the arteriovenous fistula in dialysis patients].

Duplex sonography permits non-invasive evaluation of both the anatomy and function (flow volume) of the AV-fistula in patients on hemodialysis in a single session. It should be the first imaging procedure to be applied when access to the circulation presents a problem. Comparisons with angiography and surgical reports confirm the adequate sensitivity and specificity of the procedure. Diagnostic problems may occur with ambiguous vascular anatomy, stenoses affecting the anastomosis or central veins. Duplex sonography makes the establishment of the indication for angiography or therapy much more accurate.