Numerical simulation to study the impact of compliance mismatch between artificial and host blood vessel on hemodynamics

Abstract

Small-diameter artificial blood vessels are prone to cause intimal hyperplasia (IH) after transplantation, which leads to restenosis and low long-term patency rates. The main biomechanical factor for IH formation is the compliance mismatch between the artificial and host blood vessels which can cause abnormal hemodynamics. Although there have been many studies on vascular compliance mismatches, however, little attention has been paid to the effect of the degree of compliance mismatch between graft and the host vessel on hemodynamics. At present, the research on compliance mismatch between the artificial and host blood vessels is still very limited, especially with regard to the specific impact of the compliance mismatch degree on hemodynamics. Therefore, three end-to-end anastomosis models (the compliance of the artificial blood vessel is lower than, similar to, and higher than that of the host blood vessel, called model 1, model 2, model 3, respectively) were constructed and simulated in this study. Simulation results showed that the radial displacement difference between the artificial and host blood vessels were 0.281 ​mm, 0.183 ​mm and 0.485 ​mm in model 1, model 2 and model 3, respectively. A low-velocity recirculation zone near the distal anastomosis was formed in model 1 which resulted in excessively low TAWSS (9.261 ​E-5Pa) and high OSI (0.497). Similarly, a low-velocity recirculation zone near the proximal anastomosis was formed in model 3 and lead to low TAWSS (6.007 ​E-4Pa) and high OSI (0.480). However, there was no low-velocity recirculation zone near the anastomosis stoma in model 2. The results are instructive for the design and preparation of artificial blood vessels.

Keywords

• Numerical simulation
• Artificial blood vessel
• Compliance mismatch
• Wall shear stress
• Oscillatory shear index