Numerical analysis of different arterial bifurcation lesion plaques and blood interaction

Atherosclerosis is prone to occur at arterial bifurcations. The hemodynamic and biomechanical variations across subtypes of Chen's bifurcation lesion classification are still unclear. This study adopts bidirectional fluid-structure interaction simulations to explore biomechanical features of four common Chen-classified lesion subtypes (I a , I b , II a , II b ) in 60% stenotic bifurcated arteries with unstable plaques. The assumptions of the idealized models and the finite volume computational fluid dynamic technique are used. Multiple hemodynamic and biomechanical indicators are calculated, and plaque fatigue life is evaluated via Basquin S – N curve and Palmgren-Miner rule. The results reveal significant inter-subtype differences in hemodynamic and mechanical properties. Type I a presents elevated wall shear stress and oscillatory shear index at the bifurcation ridge alongside the longest fatigue life. Types I b and II b have the short fatigue life owing to drastic stress fluctuations. Type II a possesses the highest flow velocity and time-averaged wall shear stress with obvious turbulence at branch inlets. Bifurcation ridges and proximal plaque shoulders are identified as high-risk vulnerable regions. This work offers biomechanical references for risk assessment and targeted therapy of bifurcation lesions.