Impact of Malapposed and Overlapping Stents on Hemodynamics: A 2D Parametric Computational Fluid Dynamics Study

Despite significant progress, malapposed or overlapped stents are a complication that affects daily percutaneous coronary intervention (PCI) procedures. These malapposed stents affect blood flow and create a micro re-circulatory environment. These disturbances are often associated with a change in Wall Shear Stress (WSS), Time-averaged WSS (TAWSS), relative residence time (RRT) and oscillatory character of WSS and disrupt the delicate balance of vascular biology, providing a possible source of thrombosis and restenosis. In this study, 2D axisymmetric parametric computational fluid dynamics (CFD) simulations were performed to systematically analyze the hemodynamic effects of malapposition and stent overlap for two types of stents (drug-eluting stent and a bioresorbable stent). The results of the modeling are mainly analyzed using streamlines, TAWSS, oscillatory shear index (OSI) and RRT. The risks of restenosis and thrombus are evaluated according to commonly accepted thresholds for TAWSS and OSI. The small malapposition distances (MD) cause both low TAWSS and high OSI, which are potential adverse outcomes. The region of low OSI decrease with MD. Overlap configurations produce areas with low WSS and high OSI. The affected lengths are relatively insensitive to the overlap distance. The effects of strut size are even more sensitive and adverse for overlap configurations compared to a well-applied stent.

Everolimus-eluting bioresorbablecoronary scaffold in Asian patients; a 2-yearfollow-up

Indo-Pakistan population has one of the highest risk of coronary artery disease(CAD) in the world.1Percutaneous interventions with the use of stents has been the mainstay of treatment for CAD, evolving from balloon angioplasty to bare metal stents and then to drug eluting stents. However, there are a few drawbacks related to the metal implant in the coronary, leading to the development of bio-resorbable vascular scaffolds(BVS). This case series studies the implantation techniques and 24 month clinical outcome of bioresorbable stent Absorb at Rawalpindi Institute of Cardiology. From November 1, 2013 till June 30, 2018. Fifty patients undergoing angioplasty with Absorb BVS as elective or primary PCI were enrolled. Case selection was at the discretion of the operator. Patients were followed up clinically. Repeat angiogram was conducted if clinically indicated. Continuous...