arXiv subjects

Chi Shen

Publications and source records attributed to Chi Shen.

4 recordsLinked to original sources

arXiv2026

Influence of Plaque Characteristics on Stent Biomechanical Outcomes - A Case Study on Double Kissing Crush Coronary Stenting

Background Double Kissing (DK) Crush is a two-stent technique for complex coronary bifurcation lesions, yet the biomechanical influence of plaque on its performance remains poorly understood. This study developed a computational biomechanical model of the DK-Crush procedure to quantify how plaque presence and composition affect procedural outcomes and the performance of Xience Sierra and Orsiro stents. Methods A population-representative coronary bifurcation was modelled with no plaque, lipid plaque, and fibrous plaque. The complete DK-Crush sequence was simulated using finite element analysis for both stent platforms. Mechanical outcomes included arterial wall stress, malapposition, side branch ostium clearance, and residual stenosis. Post-deployment hemodynamics was assessed using pulsatile computational fluid dynamics, quantifying high shear rate volume and lumen area exposed to low time-averaged endothelial shear stress (TAESS). Results Plaque presence and stiffness reduced lumen restoration, increased arterial wall stress, led to larger high shear rate regions and, for fibrous plaque, increased exposure to low TAESS. Malapposition and ostial clearance depended mainly on stent design. Plaque also altered the relative performance of the two platforms, revealing differences not observed in plaque-free models. Conclusions Plaque characteristics substantially affect DK-Crush biomechanics and modify stent behaviour. Incorporating plaque is therefore essential for realistic computational evaluation of bifurcation stenting.

physics.bio-ph↗

arXiv2025

Are Ultrathin Stents Optimal for Bifurcation Lesions? Insights from Computational Modelling of Provisional and DK-Crush Techniques

Complex coronary bifurcation lesions remain challenging in percutaneous coronary intervention, with stent design and deployment strategy influencing clinical outcomes. This study compares the mechanical and hemodynamic performance of the ultrathin-strut Orsiro and thin-strut Xience Sierra stent in Provisional Side Branch (PSB) and Double Kissing Crush (DKC) techniques. We used finite element analyses of bifurcation stent deployment to assess malapposition, ostium clearance, and arterial wall stress for both techniques. Computational fluid dynamics simulations quantified the luminal exposure to low Time-Averaged Endothelial Shear Stress (TAESS below 0.4 Pa) and high shear rates (above 1000 1/s). In PSB, Orsiro showed higher malapposition (13.0% vs 9.6%) but improved SB ostium clearance (77% vs 64%) and lower low-TAESS exposure (30.3% vs 33.6%) compared to Xience. Orsiro also produced higher arterial wall stresses, particularly during kissing balloon inflation. In DKC, differences in malapposition and ostium clearance diminished between stents, though Orsiro retained a hemodynamic advantage with lower low-TAESS (28.2% vs 36.3%).Stent design influenced outcomes more strongly in PSB, where anatomical interaction and platform-specific behavior impacted both structural and hemodynamic results. In DKC, procedural complexity minimized those differences, making the stenting technique the primary performance driver. Nonetheless, Orsiro consistently preserved more favorable flow conditions. These findings highlight the need to match device selection with lesion characteristics in PSB, while in DKC, optimizing procedural steps may have a greater impact than the choice of stent platform.

physics.med-ph↗

arXiv2025

High-Intensity Helical Flow: A Double-Edged Sword in Coronary Artery Haemodynamics

The role of Helical Flow (HF) in human coronary arteries remains uncertain, yet its understanding promises unprecedented insights into atherosclerotic processes. In this study, we investigated the effects of HF and key haemodynamic descriptors in 39 patient-specific left coronary artery trees from the ASOCA dataset, including 20 non-stenosed and 19 stenosed cases. Absolute HF intensity $h_2$ correlated with higher Time-Averaged Endothelial Shear Stress (TAESS) in all vessel segments regardless of stenosis (p < 0.05). In stenosed cases, this correlation was so prominent that the vessel area exposed to adversely low TAESS was reduced (< 0.5 Pa, p = 0.0001), while areas of adversely high TAESS increased (> 4.71 Pa, p < 0.05), coinciding with high $h_2$ regions. This suggests that HF in coronary arteries is not always protective as previously thought. It not only mitigates low TAESS, which is associated with long-term plaque development and restenosis, but also exacerbates adversely high TAESS, which is linked to increased plaque vulnerability and acute events. Our findings redefine the current understanding of helical blood flow's role in cardiovascular atherosclerotic disease processes.

physics.med-ph↗

arXiv2023

Exploring the Interplay of Left Coronary Tree Anatomy and Haemodynamics: Implications for Plaque Formation

The link between atherosclerosis and blood flow-induced haemodynamic luminal shear stresses is well established. However, this understanding has not been translated into clinical practice because of the interdependent effects of the complex coronary anatomy and a multitude of potential haemodynamic metrics, which have been challenging to delineate. Thus, this study aims to identify anatomical and haemodynamic differences in coronary trees at different stages of stenoses. A total of 39 left coronary trees were considered, which are publicly available. Each coronary tree was dissected into bifurcations and non-bifurcating segments for comparisons. We calculated a full set of anatomical metrics and performed transient flow simulations to solve the normalised luminal area exposed to Low Time-Average Endothelial Shear Stress (%LowTAESS), High Oscillatory Shear Index (%HighOSI), and High Relative Residence Time (%HighRRT). We statistically investigated the differences between non-stenosed (n=20, Diameter Stenosis DS=0%), moderately (n=12, 0% =70%) stenosed cases, whereby p<0.05* is considered significant. Only the average curvature and %HighOSI differed between the non-stenosed, and moderately or severely stenosed for the coronary trees (p=0.024* and p<0.001*), and non-bifurcating segments (p=0.027* and p<0.001*). %LowTAESS@0.5Pa and %HighRRT@2.5Pa-1 significantly differed between moderately (0% =70\%) stenosed trees (p=0.009* and p=0.012*). Our findings suggest curvature and potentially %HighOSI being critical factors in coronary plaque onset in non-bifurcating segments, whereas %LowTAESS and %HighRRT affect plaque progression after onset.

physics.med-ph↗