Mesh-based numerical techniques are generally categorized into body-fitted (conforming) and unfitted (non-conforming) approaches, depending on how mesh boundaries align with the geometries of the analysed bodies. In this work we aim to exploit the unfitted techniques for the efficient simulation of patient specific aortic dissection(AD) models. The methodology used in this work is based on the substitution of the standard FE space by an alternative one in those elements of background mesh that are intersected by the IF (i.e., the elements featuring both positive and negative elemental distance values) [1]. Such alternative space is capable to represent the discontinuity in the velocity and pressure fields coming from the presence of the IF. The FE space substitution is complemented a relocation of the integration points and a weak imposition of the boundary condition over the IF intersection by using the Nitche’s method [2]. The AD models are generated in two steps: initially creating a volume mesh of the aorta without distinguishing between the true lumen (TL) and false lumen (FL) (fix mesh), and then, segmenting the intimal flat (IF) to distinguish between TL and FL. The division into TL and FL is introduced into the model by calculating the level set function representing by the IF model. The level set function is automatically computed by an algorithm from the intersections of a surface mesh representing the IF and makes possible to alternatively locate the position of the IF (moving mesh) into the volume mesh, thus allowing to impose the corresponding wall boundary conditions over it [3]. By using patient-specific imaging data from CTA or 4D flow MRI, this methodology can accurately model the behavior of the dissection membrane and the aorta, capturing their dynamic deformation. This characteristic enables the resolution of a Fluid-Structure Interaction (FSI) problem without requiring any knowledge about the tissue's mechanical properties, regardless of its health status.