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Computer Assisted Stenting in Heavily Calcified Coronary Artery

Pengfei Dong, University of Nebraska - Lincoln

Abstract

Heavily calcified coronary artery is a great concern when implementing a stenting intervention. Characteristics of calcification are commonly associated with the stent underexpansion and malapposition. Post-dilatation is generally adopted to improve the stent expansion. In addition, the suboptimal stent deployment could lead to long term complications, including restenosis. However, there are scarce engineering data on the role of calcification characteristics in the acute and chronic stenting outcomes. In this work, the influence of calcification characteristics on acute stenting outcomes in term of lumen gain, stent underexpansion, strut malapposition, and lesion stress or strain distributions was quantitatively inspected using finite element method. The arterial growth model and the degradation model of bioresorbable stent were implemented to quantify the chronic response of stenting Patient-specific artery models were reconstructed from optical coherence tomography (OCT) images to investigate the impact of calcification characteristics on stenting outcomes. Stylized artery models were also developed to isolate the contribution of each calcification characteristic on stent expansion. Results have shown that the minimal lumen area following stenting occurred at the cross section with the greatest calcification angle. The calcification with a larger angle constricted the stretchability of the lesion and thus resulted in a small lumen area. The maximum principal strain and von Mises stress distribution patterns in both the fibrotic tissue and artery were consistent with the calcification profiles. Moreover, machine learning (ML) methods were utilized to predict the stent expansion in the calcified artery based on the geometrical features of the vessel. The ex-vivo and in-silico post-dilation experiments were developed to guide the selection of balloon size (diameter) and inflation pressure for heavily calcified artery. Results have shown that the lumen gain is more sensitive to balloon diameter than inflation pressure. In addition, computational framework was developed to capture the chronic remodeling of the artery as well as the degradation behavior of the PLLA stent. These detailed mechanistic quantifications could be used to provide a fundamental understanding of the role of calcification in stent expansions, as well as to exploit their potential for enhanced stenting strategies.

Subject Area

Engineering|Biomechanics|Biomedical engineering

Recommended Citation

Dong, Pengfei, "Computer Assisted Stenting in Heavily Calcified Coronary Artery" (2020). ETD collection for University of Nebraska - Lincoln. AAI27837993.
https://digitalcommons.unl.edu/dissertations/AAI27837993

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