Abstract 16998: A Novel Preclinical Model of Calcified Coronary Chronic Total Occlusion

Abstract

Introduction: These is significant research into the development of new medications and devices to treat chronic total occlusions (CTO). However, there is a lack of large animal models which reproduce the anatomy of clinical CTOs. Aim: Create an experimental model that mimics the anatomic features of human CTOs. Methods: CTOs were created in coronary arteries of live Yorkshire pigs (weight 80-120 lbs). The bioactive dental plug material (OsteoGen® Plug, Impladent Ltd) was implanted into the middle segment of one of coronary arteries (LAD, LCX or RCA). Angiography (C- Arm, Siemens) was performed before, immediately after plug implantation and before autopsy to confirm the presence of a CTO lesion. Animals were sacrificed at 9 hours to 3 months (n=12) and all coronary arteries underwent histopathological examination. Results: Histopathologic assessment confirmed that the bioactive plug composed of calcium apatite crystals and bovine collagen matrix mimics the pathological appearances of human CTOs. Serial histological sections showed complete resorption of the collagen matrix with replacement by fibrotic tissue 2 months after plug implantation, while the calcium content remains in the CTO. Conclusions: We have developed a reproducible model of calcified CTOs in pigs. Our model can provide a platform for evaluation of new drugs and devices for the treatment of calcified CTOs as well as to serve as a live model for training interventional cardiologists learning to cross CTOs.