Abstract 19390: Two Stenting at Coronary Artery Bifurcation Yields Slow-Flow Region at Carina: In vitro Pulsatile Flow Investigation Using Elastic 3-Dimensional Stenotic Bifurcated Artery Replica
Introduction: Coronary bifurcation lesions are identified as predictors of stent thrombotic events throughout real-world clinical data. However, the causes have not been well understood yet. We aimed to assess potential flow disturbances after two-stenting in an elastic three-dimensional stenotic bifurcated artery replica, using a physiological coronary circulation simulator.
Methods: Based on referenced clinical computed tomography (CT) data of left main bifurcation, an elastic stenotic bifurcated artery replica with the angles of 150° between left main coronary trunk (LMT) and left anterior descending artery (LAD), 130° between LMT and left circumflex artery (LCx), and 80° between LAD and LCx, was developed. The flow tract from LMT to the two distal bifurcated arteries was curved by 120°. The replica equipped a 60% stenosis along the vessel wall from LMT to LAD and a 50% stenosis at LCx ostium. The referenced vessel diameter for LMT, LAD, and LCx were 4.0 mm, 3.5 mm, and 3.0 mm. Using cobalt alloy stents of 3.0mm×18mm and 3.5mm×24mm, mini-crush and modified-T stenting were performed respectively. Simultaneous kissing balloon post-dilation were conducted. Under physiological pulsatile flow and pressure of 80/30(mean: 60) mL/min and 120/80(mean:100) mmHg at pulse rate of 70bpm, flow characteristics at bifurcation were investigated using particle image velocimetry technique. The stenotic and non-stenotic bifurcation replicas without stenting were included for comparison.
Results: Micro-focus CT and intravascular ultrasound examination confirmed removal of stenosis after mini-crush and modified-T stenting. However, microscopic observation revealed presence of carina surface non-covered by stents. There formed a small gap among carina tip and stent struts deployed in the main and side branches. Flow visualization study demonstrated that mini-crush and modified-T stenting both yielded distinctly slow flow region at the gap during a cycle due to blockage of incoming flow from LMT by the contact of two stents. Shear stress in the gap region after two-stenting was lower by approximately 5 times as compared with that before stenting.
Conclusions: This study revealed that two stenting at coronary bifurcation yielded slow flow region at carina.
- © 2010 by American Heart Association, Inc.