Hemodynamic Analysis on the Anastomosis Angle in Arteriovenous Graft Using Multiphase Blood Model

Hyangkyoung Kim,Hong Sun Ryou,Ji Tae Kim

doi:10.3390/app11178160

Hyangkyoung Kim, Hong Sun Ryou + Show 1 more

Open Access

https://doi.org/10.3390/app11178160

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Abstract

Numerical analysis was performed for the effect of the venous anastomosis angle in a forearm arteriovenous graft for hemodialysis using a multiphase blood model. The geometry of the blood vessel was generated based on the patient-computed tomography data. The anastomosis angles were set at 15°, 30°, and 45°. The hematocrit was set at 34%, 45%, and 58%. The larger anastomosis angle, high wall shear stress area >11 Pa, increases to the side of the vein wall away from the anastomosis site. Further, the relatively low wall shear stress area, <3 Pa, occurs near the anastomosis site in larger anastomosis angles. Therefore, the effect of high wall shear stress has advantages in the vicinity of the anastomosis, as the anastomosis angle is larger, but disadvantages as the distance from the anastomosis increases. Moreover, patients with low hematocrit are advantageous for WSS area.

Highlights

Anastomosis Angle in ArteriovenousA lasting functioning vascular access is essential for renal function replacement therapy by hemodialysis
Surgical vascular access creation, including arteriovenous fistula (AVF) and arteriovenous graft (AVG), are the preferred options for long-term dialysis compared to central venous catheters [1]
The patency of vascular access for hemodialysis is mostly limited by growing stenoses that lead to decreased flow rate, thromboses, and, access failure

Summary

Introduction

Anastomosis Angle in ArteriovenousA lasting functioning vascular access is essential for renal function replacement therapy by hemodialysis. Surgical vascular access creation, including arteriovenous fistula (AVF) and arteriovenous graft (AVG), are the preferred options for long-term dialysis compared to central venous catheters [1]. The dialysis access creation technique is widely used in clinical practice, long-term patency remains an unsolved major clinical problem for chronic hemodialysis treatment and a leading cause of morbidity and hospitalization in these patients [2]. Several risk factors are related to the patency of dialysis access, including sex, vessel size or distensibility, surgical technique, hypoxia, and an underlying uremic condition, but no clear pathophysiology has been elucidated yet [3,4,5]. Intimal hyperplasia has been widely studied in various vascular bypass surgeries, not limited to vascular access creation [7,8]. Simulation or animal studies have reported that disturbed flow regions are seen at the heel, the toe, and at the floor of the distal end-to-side anastomosis, which corresponds to the disturbed flow regions [9]

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