Stenting in coronary bifurcations: an image-based structural simulation of a clinical case

S. MORLACCHI; S. COLLEONI; C. CHIASTRA; R. CARDENES; I. LARRABIDE; J. L. DIEZ; A. F. FRANGI; G. DUBINI; F. MIGLIAVACCA

Marseille

Congreso; Endocardiovascualr Biomechanics Research Symposium; 2012

Introduction - The majority of current models simulates standard stenting procedures in idealized geometries. Consequently, such models can only provide standard guidelines without specific indications for the optimal planning of each patient treatment. The aim of this work is the implementation of a patient-specific structural model that uses image-based reconstructions of atherosclerotic bifurcations. Particular attention is paid to the plaque identification and the positioning of stents by simulating their advancement in the artery. Two clinical cases have been investigated. Materials and Methods - The pre-stenting configurations generated from conventional coronary angiography (CCA) and computed tomography angiography (CTA) [1] are used to construct 3D solid models (Fig. 1a) of the arteries. The diameters of the external wall are chosen in order to respect physiological values of the arterial branches investigated. The geometry is discretized using Ansys ICEM CFD (ANSYS Inc., Canonsburg, PA, USA) with a fully hexahedral mesh. Atherosclerotic plaques are identified based on the distance between each node and the centerline of the external wall surface (Fig. 1b). Structural models implemented in Abaqus (Dassault Systemes Simulia Corp., USA) are used to simulate the advancement of the device in the curved artery (Fig. 1c) and replicate the clinical stenting protocol [2]. Results - Figure 1d shows the expansion of a 28 mm long Multilink stent in the bifurcation and following proximal over-dilatation with a 3.00 mm balloon. Re-opening and straightening of the artery are evident and mainly caused by the insertion of the rigid metallic stent. Deformations and stresses are examined both in the device and the vessel. Conclusions - This work shows the feasibility of implementing a patient-specific virtual model replicating actual clinical cases. Further developments will imply CFD simulations [2], the analysis of different interventional options and the comparison with immediate post-stenting and follow-up configurations.