Venturi-effect ultrasonography for early detection of AVF stenosis: a prospective multicenter study

This study aims to evaluate the diagnostic value of the Venturi effect combined with conventional ultrasonographic indicators for the early detection of arteriovenous fistula (AVF) stenosis in hemodialysis patients. A total of 169 patients with suspected AVF dysfunction were enrolled from January 2019 to June 2024 at the Department of Nephrology. Ultrasound parameters assessed including the minimal lumen diameter (MD) at the suspected stenosis site of the cephalic vein, the Venturi effect presence, peak systolic velocity (PSV), peak systolic velocity ratio (PSVR), brachial artery resistance index (BA-RI), and the flow volume difference (ΔFV). The diagnostic performance of each individual conventional parameter was compared with that of its combination with the Venturi effect for early AVF stenosis detection. Among the 169 patients, 158 were confirmed as stenotic. The conventional ultrasound indicators with the highest sensitivity and specificity for diagnosing AVF stenosis were MD, with a sensitivity of 93.7% and specificity of 93.8%. The area under the receiver operating characteristic curve (AUC) of individual parameters was ranked from highest to lowest as follows: AUC_MD > AUC_BA-RI > AUC_PSV > AUC_PSVR > AUC_ΔFV. After combining the Venturi effect with each indicator, diagnostic sensitivity for AVF stenosis improved to varying degrees. Among them, the diagnostic performance of PSV, PSVR and ΔFV has significantly improved (P < 0.005). The Venturi effect combined with conventional ultrasonographic indicators demonstrates high diagnostic efficacy in the early diagnosis of AVF stenosis.