Diagnostic performance and inter-reviewer agreement of colour Doppler ultrasound in haemodialysis fistula and graft complications: a multicentre prospective study

Purpose
Haemodialysis provides various options for vascular access, including native arteriovenous fistulas (AVFs), arteriovenous grafts (AVGs), and central intravenous catheters. However, the use of catheters should be avoided due to their association with greater risks when opposed to AVFs or AVGs. AVFs have garnered strong endorsement as the favoured vascular access choice for extended haemodialysis.

Material and methods
A total of 200 patients initially diagnosed with AVF/AVG dysfunction were referred to the radiology department across 3 different institutions. The inclusion criteria involved patients who encountered repeated difficulties with access cannulation during dialysis. Conversely, the exclusion criteria comprised cases that had been solely assessed using colour Doppler ultrasound (CDUS), those exclusively evaluated with digital subtraction angiography (DSA), situations where DSA was not feasible, instances requiring immediate intervention due to acute access failure, and cases in which patients refused participation.

Results
Inter-observer agreement regarding complications of AVF/AVG was very good for the identification of thrombus (κ = 1.0), seroma (κ = 0.953), aneurysm (κ = 0.851), and pseudoaneurysm (κ = 0.851). It was considered good for the detection of juxta-anastomosis stenosis (κ = 0.751) and feeding artery stenosis (κ = 0.638). However, the agreement was fair for identifying draining vein stenosis (κ = 0.380) and distal arterial steal syndrome (κ = 0.210). The overall diagnostic performance of CDUS exhibited 86% sensitivity in identifying stenosis, with a specificity of 99.1%, a positive predictive value (PPV) of 96.5%, a negative predictive value (NPV) of 97%, and an accuracy of 94.3%.

Conclusions
CDUS is a noninvasive diagnostic approach for the prompt picking of AVF complications. It serves as a suitable first-line imaging modality for nonfunctional AVF due to its cost-effectiveness and accessibility. Additionally, we provide evidence of reproducibility, encouraging the diligent use of CDUS in AVF and AVG evaluation for early complication detection and management guidance.