Comparison of overexpansion capabilities and thrombogenicity at the side branch ostia after implantation of four different drug eluting stents

Pawel Gasior,Nicolas Foin,Chen Koon Jaryl Ng,Elvin Kedhi,Hui Ying Ang,Wee Yee Daniel Toong,Wojciech Wojakowski,En Hou Philip Wong,Shengjie Lu

doi:10.1038/s41598-020-75836-6

Abstract

Interventions in bifurcation lesions often requires aggressive overexpansion of stent diameter in the setting of long tapering vessel segment. Overhanging struts in front of the side branch (SB) ostium are thought to act as a focal point for thrombi formation and consequently possible stent thrombosis. This study aimed to evaluate the overexpansion capabilities and thrombogenicity at the SB ostia after implantation of four latest generation drug-eluting stents (DES) in an in-vitro bifurcation model. Four clinically available modern DES were utilized: one bifurcation dedicated DES (Bioss LIM C) and three conventional DES (Ultimaster, Xience Sierra, Biomime). All devices were implanted in bifurcation models with proximal optimization ensuring expansion before perfusing with porcine blood. Optical coherence tomography (OCT), immunofluorescence (IF) and scanning electron microscope analysis were done to determine thrombogenicity and polymer coating integrity at the over-expanded part of the stents. Computational fluid dynamics (CFD) was performed to study the flow disruption. OCT (p = 0.113) and IF analysis (p = 0.007) demonstrated lowest thrombus area at SB ostia in bifurcation dedicated DES with favorable biomechanical properties compared to conventional DES. The bifurcated DES also resulted in reduced area of high shear rate and maximum shear rate in the CFD analysis. This study demonstrated numerical differences in terms of mechanical properties and acute thrombogenicity at SB ostia between tested devices.

Highlights

Interventions in bifurcation lesions often requires aggressive overexpansion of stent diameter in the setting of long tapering vessel segment
The rate of well apposed struts was numerically higher in the Bioss LIM C group when compared to the conventional drug-eluting stents (DES)
Thrombus area was numerically smaller in bifurcation dedicated DES when compared to the Ultimaster, Biomime and Xience Sierrra (Bioss LIM C: 0.00 (0.00–0.04) m m2 vs. Ultimaster: 0.24 (0.24–0.26) m m2 vs. Biomime 0.60 (0.37–0.67) m m2 vs. Xience Sierra 0.52 (0.31–0.58) m m2, p = 0.113)

Summary

Introduction

Interventions in bifurcation lesions often requires aggressive overexpansion of stent diameter in the setting of long tapering vessel segment. This study aimed to evaluate the overexpansion capabilities and thrombogenicity at the SB ostia after implantation of four latest generation drug-eluting stents (DES) in an in-vitro bifurcation model. Lesions located in bifurcations lesions are prone to delayed arterial healing following stent implantation[3] This is especially important in the left main coronary artery (LMCA) bifurcation interventions where large amount of myocardium remains at risk and stenting techniques tend to be complex and are associated with high incidence of adverse e vents[10]. Provisional stenting seems to be preferred strategy for bifurcation lesion treatment, especially in non-severe side-branch ostial involvement. Bifurcation interventions often requires aggressive overexpansion of stent diameter in the setting of long tapering vessel segment. Benchtop models and evaluations have been conducted to assess optimization of side branch re-crossing, crush, culotte and kissing balloon inflation techniques

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Conclusion