Background

Coronary artery restenosis is an important side effect of percutaneous coronary intervention. Computational models can be used to better understand this process. We report on an approach for validation of an in silico 3D model of in-stent restenosis in porcine coronary arteries and illustrate this approach by comparing the modelling results to in vivo data for 14 and 28 days post-stenting.

Methods

This multiscale model includes single-scale models for stent deployment, blood flow and tissue growth in the stented vessel, including smooth muscle cell (SMC) proliferation and extracellular matrix (ECM) production. The validation procedure uses data from porcine in vivo experiments, by simulating stent deployment using stent geometry obtained from micro computed tomography (micro-CT) of the stented vessel and directly comparing the simulation results of neointimal growth to histological sections taken at the same locations.

Results

Metrics for comparison are per-strut neointimal thickness and per-section neointimal area. The neointimal area predicted by the model demonstrates a good agreement with the detailed experimental data. For 14 days post-stenting the relative neointimal area, averaged over all vessel sections considered, was 20 ± 3% in vivo and 22 ± 4% in silico. For 28 days, the area was 42 ± 3% in vivo and 41 ± 3% in silico.

Conclusions

The approach presented here provides a very detailed, location-specific, validation methodology for in silico restenosis models. The model was able to closely match both histology datasets with a single set of parameters. Good agreement was obtained for both the overall amount of neointima produced and the local distribution. It should be noted that including vessel curvature and ECM production in the model was paramount to obtain a good agreement with the experimental data.

中文翻译：

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3D支架内再狭窄模型与来自猪体内实验的Micro-CT和组织学数据之间的特定位置比较。

背景

冠状动脉再狭窄是经皮冠状动脉介入治疗的重要副作用。计算模型可以用来更好地理解这一过程。我们报告了一种验证猪冠状动脉支架内再狭窄的计算机3D模型的方法，并通过将建模结果与支架后14天和28天的体内数据进行比较来说明这种方法。

方法

该多尺度模型包括用于支架部署，支架血管中血流和组织生长的单尺度模型，包括平滑肌细胞（SMC）增殖和细胞外基质（ECM）产生。验证程序使用来自猪体内实验的数据，方法是使用从支架血管的显微计算机断层扫描（micro-CT）获得的支架几何结构模拟支架部署，并将新内膜生长的模拟结果与在相同位置进行的组织学切片直接进行比较。

结果

用于比较的度量标准是每个支柱的新内膜厚度和每个截面的新内膜面积。该模型预测的新内膜面积与详细的实验数据显示出良好的一致性。支架置入后14天，在所有考虑的血管切片中，平均相对新内膜面积在体内为20±3％，在计算机上为22±4％。28天的体内面积为42 ±3％，计算机模拟面积为41±3％。

结论

此处介绍的方法为计算机再狭窄模型提供了非常详细的，针对特定位置的验证方法。该模型能够使用一组参数将两个组织学数据集紧密匹配。新内膜产生的总量和局部分布均获得了良好的共识。应该注意的是，在模型中包括血管曲率和ECM产量对于与实验数据取得良好一致性至关重要。