A novel geometric model of blood flow in stenosed small arteries with luminal surface irregularities

The main goal of this study is to develop a novel geometric model for blood flow in stenosed small arteries. Blood is represented as a couple stress fluid, and the effects of the luminal surface irregularities are explicitly incorporated. The model describes flow behavior upstream of, within, and downstream of the stenotic region. The problem’s governing equations and the corresponding boundary conditions were set dimensionless via suitable quantities. The problem complexity was simplified, and closed-form analytical solutions were derived by carrying out the assumptions of lubrication approximation and low Reynolds number. This study presents an in-depth analysis to relate geometric parameters to hemodynamic variables (wall shear stress, pressure gradients). The significant role of pertinent parameters was displayed through plots. It has been noted that the small-scale stenotic surface irregularities superimpose high-frequency oscillations to the overall magnitude and shape of the pressure and shear stress profiles. Alignment of out-of-phase surface irregularities creates highly tortuous flow paths, whereas in-phase surface irregularities generate a single broad bell-shaped peak. The results provide mechanistic insight into the hemodynamic effects of luminal irregularities in stenotic lesions of small arteries. They may also contribute to future diagnostic and therapeutic approaches for arteriolosclerosis