Doppler ultrasound: a powerful tool for vascular access surveillance.

National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF KDOQI) guidelines recommend Doppler ultrasound (DU) for surveillance of vascular access (VA), but trials have not been unanimous about its benefit on VA patency. The aim of this study was to evaluate the accuracy of DU for patency, as well as to highlight additional data provided by this method. A transversal study was conducted to evaluate DU method in correlation with BTM using paired t-test and Pearson test. Ultrasonography evaluation was performed with a Siemens Acuson X150 Ultrasound device and BTM-Qa with the Blood Temperature Monitor BTM(®). Access blood flow (Qa) values were correlated with several factors by nonparametric tests. Fifty hemodialysis patients were included, with mean age of 64.5 ± 13.7 years; durations of hemodialysis and VA were 51.4 ± 47.3 and 47.6 ± 42.1 months, respectively. The mean difference between DU and BTM flows was 20.5 ml/minute (p 0.624). Pearson correlation was 0.851 (p < 0.001). DU-Qa values varied significantly with several factors: type of VA, reason for DU referral, the presence of artery stenosis, and the location and number of stenosis. BTM-Qa values only varied significantly with the presence and number of stenosis. Various silent abnormalities were detected with DU. DU provides accurate anatomic and hemodynamic data to further knowledge regarding the etiology of stenosis and other abnormalities that compromise VA well functioning.