Agreement between physical and ultrasound examination for arteriovenous fistula maturation diagnostics in Thai hemodialysis patients

Abstract

Introduction: Physical examination (PE) is used to determine if arteriovenous fistula (AVF) meets criteria for first hemodialysis (HD) cannulation in chronic kidney disease (CKD) with HD patients. Three ultrasound (US) based criteria are adopted to investigate maturation: (i) Rule of Six: blood flow ⩾600 milliliters per minute (mL/min), vein diameter ⩾6 millimeters (mm), vein depth ⩽6 mm); (ii) Rule of Five: blood flow ⩾500 mL/min, vein diameter ⩾5 mm, vein depth ⩽6 mm; and (iii) Rule of Four: blood flow ⩾500 mL/min, vein diameter ⩾4 mm, vein depth ⩽6 mm. In Thai, no study determined optimal US criteria for predicting AVF maturation measured by PE before first cannulation. This study examined the significance of these US criteria on the physical AVF maturation in Thai. Methods: Fifty CKD patients, operated brachiocephalic AVF, were enrolled and examined on the operative day and 6 weeks afterwards. PE was evaluated by an experienced vascular surgeon, and US measurements were obtained by an experienced US technologist. Matching mature number between US criteria and PE was computed using McNemar test. Agreement between US criteria and PE was measured using Kappa. Mature and immature discrimination were evaluated by the Receiver Operator Characteristics (ROC) curve and Youden index. Results: Rule of Six and Rule of Five had higher non-mature matching number than Rule of Four ( p < 0.001 both). Regarding Kappa statistics, Rule of Six and Rule of Five agreed with the PE ( p < 0.01 both). The ROC curve of Rule of Six and Rule of Five were 0.75 and 0.74, respectively ( p <0.01 both). Youden index (maturity and immaturity discriminating performance) of both rules was 0.5 and 0.47, respectively. Conclusion: Rule of Six and Rule of Five agreed with the PE, with the highest performance of the Rule of Six to predict first successful cannulation in Thai.