This work introduces a mathematical model and its numerical implementation within a finite element (FE) framework to investigate the progression of atherosclerosis, a prevalent vascular disease characterized by abnormal thickening of the arterial wall. The model follows the outside-in paradigm, which attributes the disease's origin to the dysfunction of the vasa vasorum (VVs) the microvascular network responsible for nourishing the artery wall. Vasa vasorum malfunction triggers an inflammatory response, leading to excessive tissue growth and wall thickening, ultimately causing stenosis and narrowing of the lumen. Additionally, this inflammatory process induces abnormal mechanical stresses within the arterial wall and activates homeostatic growth mechanisms. The interplay between inflammation and stress-driven growth governs the disease's progression. The numerical implementation is facilitated by AceGen, a symbolic and automatic differentiation tool, enabling the generation of a FORTRAN subroutine that interfaces with the FEM solver ANSYS.