A new method to determine anastomosis angle configuration for arteriovenous fistula maturation

Background: The kidneys of patients with chronic kidney disease (CKD) do not function well enough and those in end-stage renal disease (ESRD) of CKD need hemodialysis (HD) as a common renal replacement therapy (RRT) procedure. HD requires a vascular access (VA), and arteriovenous fistula (AVF) is the common VA choice in the world due to its very few complications. Despite the widespread use of AVFs, some risk factors maximize AVF failure, which is accompanied by complications of the patient such as repeating VA surgeries and hospitalization. Therefore, finding effective factors in the success of surgery is highly important and, thus, this study aimed at measuring the effect of anastomosis angle on the success of AVF surgery. Methods: This study evaluated the effect of conducted angle in an AVF anastomosis on AVF maturation. The images of 48 created AVFs for CKD patients was provided over a one-year period (from May 2016 to April 2017). Cross-tab analysis was used, and significance level was considered meaningful at p-value≤0.001. A centralized database was designed to integrate data. A method for image processing was developed and geometrical characteristics of the vessels (such as anastomosis angle) and also the diameter of artery and vein were measured via AutoCAD 2017 software and exported to the database along with other data. Results: The rate of the AVF failure in the studied patients was 8.96%. The anastomosis angle ≤ 30° is preferable from the AVF status point of view because most AVF maturation (or least AVF failure) rates are detected at this range. Conclusion: This study was performed based on a new approach without the need to measure hemodynamic parameters. Moreover, it signified the important role of anastomosis angle in the function of AVF, showing that the anastomosis angle ≤ 30° is a preferable intraoperative recommendation for AVF surgery.