In vivo evaluation of a novel compliance-matching vascular graft

Abstract

BackgroundThe mismatch of elastic properties between the arterial tissue and the vascular grafts, commonly called compliance mismatch, is responsible for many deleterious post-operative complications. Currently, there is an absence of prostheses that conform with the compliance of healthy aortas. ObjectivesWe proposed a novel compliance-matching graft design, composed of a standard aortic graft surrounded by an optimized Nickel-Titanium compliance-augmenting layer. We aimed to evaluate the in vivo performance of the novel grafts in a swine model and compare it to the native aorta and to gold-standard aortic grafts. MethodsWe replaced the thoracic aorta of six domestic pigs with compliance-matching grafts under cardiopulmonary bypass. We removed the compliance-regulating layer of the compliant grafts, so that gold-standard grafts remained implanted. ResultsThe compliance-matching grafts were implanted without surgical complications and without inducing post-operative hypertension by maintaining systolic pressure (11% increase), aortic pulse wave velocity (17% decrease) and aortic distensibility (40% increase) at healthy levels. The gold-standard grafts caused a significant rise in systolic pressure (47%), pulse pressure (126%) and pulse wave velocity (64%). ConclusionsOur novel compliant grafts could diminish the complications caused by compliance-mismatch and they could surpass the clinical performance of existing prostheses. The proposed grafts comprise a step towards optimized treatment and improved life expectancy of patients subjected to aortic replacement.