Development of a prosthetic coronary artery bypass graft

The patient population undergoing repeat coronary revascularization is increasing, with estimates of approximately 15% of these patients in need of alternative conduits. Pre-existing conditions may limit the availability of suitable autogenous vessels for complete coronary revascularization. As an alternative, previous investigators have attempted to develop prosthetic conduits for coronary artery bypass grafting (CABG), but as yet without clinical success. To be of clinical benefit, a prosthetic graft would require demonstrated patency at least as good as a marginal quality autogenous vessel used in the same position, without unexpected adverse effects. The use of a prosthetic graft may also reduce surgical complications associated with conduit harvesting and thereby enhance the speed of patient recovery.

Our group has investigated the potential of a novel synthetic small diameter vascular graft (2.5- to 3.5-mm diameter), as an alternative conduit for CABG. The graft is designed with three distinct layers composed of Thoralon, a proprietary polyetherurethaneurea with a silicone-based surface modifying additive. This biomaterial is the same material successfully used for the thromboresistant blood-contacting surfaces of an FDA approved and clinically successful ventricular assist device.

Aria grafts underwent extensive preclinical testing in sheep with results to over one year that demonstrate the graft's biocompatibility, biodurability, and ability to maintain patency in both peripheral access graft and coronary applications. Compassionate use human coronary implants have been performed in 27 patients in the coronary position in Canada and Europe. Although incomplete, the data demonstrate no device related serious injury or and all surviving patients have remained symptom free.

A prosthetic coronary artery bypass graft has been developed and has undergone extensive pre-clinical testing and preliminary clinical use. Based upon the results, a prospective, randomized, controlled clinical study, the AEGIS/Canada (AlternativE Graft Investigational Study) trial using the Aria graft in the coronary position in human patients is underway. Additionally, a pre-IDE submission has been submitted to the FDA to expand the AEGIS clinical trial device to the United States.