Realistic anatomical model reconstruction and high-fidelity flow computation in stented coronary arteries for the analysis of in-stent thrombosis.

BACKGROUND AND AIMS: This article aims to develop and validate a methodology for realistic anatomical reconstruction of stented segments from optical coherence tomography (OCT) and angiographic images and the computation of local haemodynamic forces using computational fluid dynamics, towards a more realistic haemodynamic characterisation in coronary atherosclerotic lesions post-PCI. METHODS: Three-dimensional anatomical models of stented vessels (6 silicone models in vitro and 16 patient models) were reconstructed from OCT and angiography, using a new methodology called REFINED, which relies on the separate reconstruction of the lumen and the stent; these two are then fused in a single model. Blood flow simulations were performed using the anatomical models to calculate the endothelial shear stress (ESS) and shear rate (SR). The models were geometrically and haemodynamically evaluated against those reconstructed using conventional models. RESULTS: The reconstruction error distance was smaller with the REFINED approach than with the conventional approach, in both the silicone and patient models [8 (2-15) μm vs 23 (10-54) μm, p < 0.001, and 19 (9-32) μm vs 19 (7-36) μm, p < 0.001]. The REFINED method depicted higher ESS at the top of the struts in both the silicone (8.01 (4.21-14.92) Pa vs 5.54 (2.96-9.63) Pa; p < 0.001) and patient models [2.41 (1.41-3.65) Pa vs 1.44 (0.77-2.52) Pa; p < 0.001], and a more spatially heterogeneous SR compared to the conventional approach (p < 0.001 for all analyses). CONCLUSIONS: The REFINED approach outperforms the conventional method in reconstructing stent geometry and has been shown to be effective in facilitating a high-fidelity computation of the highly disturbed local haemodynamic environment. This demonstrates its potential role in examining device failure.