Arterio-Venous Fistula Recirculation in Hemodialysis: Causes and Prevalences

Abstract

Introduction: The measurement of Arterio-Venous (A-V) Fistula Recirculation has important diagnostic implications because the efficiency of haemodialysis (HD) may be limited, resulting in dialysis delivery being less than that prescribed. The purpose of the study is to determine its prevalence and causes in our HD patients. Materials and Methods: We randomly selected 100 end stage renal disease patients with AV fistula that they were on HD more than 3 months. The degree of recirculation was also measured with Urea based two needle technique method. For each patient distances between arterial and venous and distances of needles from fistula and its directions was recorded. Echocardiography and A-V fistula Color Doppler Ultrasound were also performed. Results: Blood flow rate and dialysate flow rate were 300 mL/min and 500 mL/min respectively. The prevalence of A-V fistula recirculation was 17% (17patients).Average degree of recirculation between these patients was 9.562.32 %. The most common cause was misplacement and or misdirection of needles (17 patients). The second cause was heart failure with Ejection Fraction > 40% (8 patients). No difference was seen between diabetic versus non diabetic (P =0.28) and hypertensive versus normotensive (P =0.21%) HD patients. Conclusions: A-V fistula recirculation is common occurrence in HD patients and the most common cause of recirculation is misplacement and or misdirection of needles so we should have more emphasis on education and training of HD staffs.