Background and Purpose: Intracerebral hemorrhage (ICH)’s ictus frequently locates in the lenticulostriate arteries (LSAs) which are perforator arteries from the horizontal segment (M1) of middle cerebral artery (MCA). LSAs supply the basal ganglia and the internal capsule. And the arteriopathy of LSAs may increase the occurrence of ICH. The goal of this study is to clarify the pathogenesis of ICH in the LSAs and provide a basic theory on the prevention of ICH. At the previous stage, computational Fluid dynamics (CFD) technology has been used to qualitatively analysis blood pressure and flow velocity in LSAs to investigate the initial state of ICH.
Methods: Firstly, 2D model of LSAs is generated by GAMBIT2.4.6, including M1 segment of MCA (the diameter of 3 mm, the length of 1 mm), three levels of LSA branches (the diameter of 0.1 mm, 0.1mm, 0.2mm, respectively). Secondly, the circulating Fluid dynamics is simulated under pulsatile Flow conditions using FLUENT6.3.26.Navier-Stokes equation (N-S equation) has been used to perform numerical calculation of Newton fluid (circulating blood: density ρ=1055 kg/m3, dynamics viscosity υ=3.3*10-4 Pa·s), and the vessel walls are assumed to be rigid. The inlet pressure of M1 has the simplified waveform of an aortic with period T=0.8s. The outlet pressure at M1 and LSAs are imposed to be 10667 Pa.
Results: It shows from contours of velocity magnitude that the velocity is intimately associated with the diameter of LSAs. The bigger the diameter is, the faster the velocity is. Relative to the same diameter of LSAs, the different location of LSAs show great difference on the velocity as well. With the computed streamlines, there are vortical structures in the origin of LSAs. From contours of total pressure, blood pressure in LSAs and M1 reduces gradually. With LSAs closer to the inlet of M1, the pressure gradient along LSAs is increased significantly. Besides, the pressure change demonstrates that the total pressure in M1 and LSAs changes periodically in a waveform.
Conclusion: The pressure and velocity distributions in LSAs tend to be relevant to the diameter and original position of LSAs. However, to improve CFD model in this study, additional investigations should be performed to evaluate the relevance of the vasoactivity.