Back to 2016 Annual Meeting Cardiac Track

OBJECTIVE: Clinical and experimental approaches to directly measure flow in epicardial coronary arteries, coronary bypass grafts, and anastomoses are severely limited by the invasiveness and inaccuracy of existing technologies. As a result, < 25% of patients undergoing CABG worldwide have any intraoperative evaluation performed. The advent of a simple, accurate and non-invasive technology to directly quantify blood flow in conduits and rheology at anastomotic sites would provide intraoperative quality documentation and new physiologic information that would improve outcomes.
METHODS: The fact that existing technologies are unable to meet this demand necessitated a different technology solution. Using an optical physics approach, flow in conduits and tissue can be quantified in real time with non-ionizing broad-spectrum imaging and temporal and spatial analyses. In particular, cardiac motion must be addressed so that flow can be quantified at any point throughout the cardiac cycle.
RESULTS: This new, proprietary and patented technology is demonstrated in the FIGURE in an established porcine cardiac experimental model. Flow velocities and flow in the mid-distal left anterior descending coronary artery (white box) vary with the cardiac cycle. The quantified change in flow velocity in the mid-distal LAD is shown by the blue curve within each cardiac cycle and at end-systole (middle panel) and end-diastole (right panel). These imaging data are captured, analyzed and displayed in real-time as a video from a viewing distance of 30 cm. The field of view of is 9 cm x 9 cm, large enough to capture flow in the proximal and distal epicardial coronary, the conduit, and at the anastomosis simultaneously.
CONCLUSIONS: The rheologic interaction between conduit flow and native coronary flow at the anastomosis remains the most poorly understood aspect of coronary artery bypass grafting. A non-invasive, non-contact, no-risk imaging technology as simple as a snapshot can provide this critical physiologic information, validate and document intraoperative quality, and improve even further CABG outcomes.