Coronary artery bypass grafting (CABG) relieves coronary artery diseases by bypassing stenosed regions of the coronary vascular. Over 400,000 CABGs are conducted each year in the U.S. alone, and over 6% of these grafts fail in the first 12 months. We postulate that some of these failures are due to mechanical mismatch between the grafted vessel and coronary circulation. We’ve tested this hypothesis through biaxial mechanical testing fit to a continuum mechanics framework. Our results show that a correlation exists between observed clinical failure rates and the degree of mechanical deviation from a vessels in situ and grafted environment. We have provisional patent on a device, “The Descartes Perfusion Bioreactor” capable of improving vascular grafts prior to implantation.