Abstract: Objective The primary purpose of this study is to explore the clinical value of ultrasound dilution (UD) technology for vascular access flow detection among patients undergoing maintenance hemodialysis (MHD) by conducting a single-center retrospective study. Methods We retrospectively studied the clinical
characteristic data and detection results from Transonic HD02 hemodialysis monitor, collected from a cohort of 213 patients undergoing MHD longer than six months in our hemodialysis center. UD was applied to detect the blood flow, access flow (Qa), cardiac output (CO), Qa/CO, cardiac index (CI) in MHD patients with arteriovenous fistula (AVF). Results ①Comparative results from two independent samples grouped by access flow (Qa ＜500 ml/min vs. Qa ≥500ml/min) indicated that significantly higher prevalence of fistula thrombus and vascular stenosis could be found in patients with Qa＜500 ml/min when compared to those with Qa≥ 500ml/min (38.235% vs. 11.173%; c2=15.983; P＜0.001 and 20.588% vs. 1.676%; c2=22.840; P＜0.001, respectively),②Results from multivariate logistic regression analysis indicated that vascular stenosis was a significant risk factor for Qa insufficiency (OR=14.192, 95% CI 3.410～59.056, P＜0.001), while the associations of Qa insufficiency with age, diabetes mellitus and time of AVF use were insignificant; ③Both actual flow in fistula and Qa were significantly improved after the intervention towards AVF stenosis; ④For patients with Qa ≥500ml/min, no significant differences were found between baseline results and the figures one year later concerning left ventricular volume and left ventricular ejection fraction (t=-0.424, P=0.681; t=0.497, P=0.631). Conclusion For patients with AVF, AVF thrombus and vascular stenosis were associated with lower AVF flow, and notably vascular stenosis acted as an independent risk factor. It is of great clinical value to detect Qa based on UD technology among MHD patients to maintain vascular access, especially for effectively recognizing access dysfunction. A multi- center prospective cohort study based on a larger scale is on our schedule to further validate the findings from this study.

Key words: hemodialysis, ultrasound dilution, vascular access, access recirculation, access flow, arteriovenous fistula