Background: The rope-ladder technique is the traditional AVF cannulation technique for HD. The buttonhole technique with repeated puncture with a blunt AV needle into a single selected site of AVF is a reliable alternative technique and has been used in Thailand for a few years. The ultrasound dilution technique is a noninvasive method to measure and monitor vascular access blood flow of patients receiving HD. There is no previous report about the evaluation of access blood flow in the buttonhole technique.
Objective: To measure vascular access blood flow by noninvasive ultrasound dilution in HD patients using the buttonhole technique for cannulation of AV needle to AVF and investigate the factors associated with impaired vascular access blood flow.
Material and Method: A cross-sectional study evaluating HD patients using the buttonhole technique at the outpatient HD center of Rajavithi Hospital and National Kidney Foundation at the Priest Hospital in Thailand was performed. The blood flow rate of AVF was measured by the ultrasound dilution technique. After starting HD with cannulated AV needle to AVF by the buttonhole technique and increasing dialyzer blood flow rate according to their HD prescription, measurements of blood flow of vascular access were evaluated within the first hour of the HD session by 2 consecutive measurements.
Results: A total of sixty eight HD patients were recruited. All patients had functioning AVF and received an adequate dialysis delivery dose, but 14.7% of them had impaired access blood flow. The average access flow rate was 1,326 + 858.8 ml/min. The average access flow rate of patients with good and impaired access flow rates was 1,497.8 + 812.4 and 330.0 + 135.0 ml/min. The factors associated with impaired access blood flow were old age, diabetes mellitus and dyslipidemia.
Conclusion: This present study suggests that annual direct measurement of access blood flow as ultrasound dilution technique is an acceptable tool to screen AVF dysfunction, especially HD patients of old age, and/or with diabetes mellitus and dyslipidemia.

Keywords: Vascular access blood flow, Hemodialysis, Buttonhole cannulating technique