Comparative analysis of bypass vs. stent for coronary revascularization using an ex-vivo organ care system in an animal model

Many patients with coronary artery disease are eligible for either percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Technical and clinical aspects influence the decision for either treatment. However, biological effects of PCI and CABG on long-term coronary artery anatomy and physiology should be considered but are largely unknown. Eight German landrace swine were used in this study. An artificial atherosclerotic plaque (AAP) was implanted into the left anterior descending coronary artery (LAD) to simulate coronary atherosclerosis. Physiological changes of PCI and surgical CABG in vascular and perivascular tissue were assessed in an ex vivo setting (organ care system OCS). Furthermore, radiological and nuclear imaging was performed using single photon emission computed tomography (SPECT) and computed tomography (CT). Furthermore, interventional (PCI) and surgical (CABG) treatment was evaluated using an ex-vivo setting. Lymphatic flow and myocardial perfusion were improved in pigs in the CABG group compared to the PCI group. The PCI group showed a significantly higher mean count number proximal to the intervention in the LAD area. Stenting experiments showed a significantly higher mean count number proximal to the intervention in the LAD area. This effect could also be demonstrated macroscopically, as myocardial infarct areas were smaller and myocardial function was better after defibrillation in the OCS (organ care system) in the CABG treated hearts. The artificial atherosclerotic plaque model in porcine hearts is a new valuable tool to simulate coronary artery stenosis without damaging other organs. It may serve as a tool for future medical testing and for further specific research on coronary artery physiology. Our data suggest that the cardiac lymphatic vascular system and perfusion capability are partly restricted after PCI as compared to CABG.