OBJECTIVE:

Currently, there is no simple and effective method for validating the quality of a coronary artery bypass graft in the operating room. Here we report our initial experience with a novel technology for visualizing the coronary vasculature on the operating table at the time of a CABG procedure. This technique involves the acquisition of images of the coronary vasculature during the first pass of a bolus of a fluorescent contrast agent through the field of view.

METHODS:

Image acquisition entails positioning an imaging device, (Novadaq Technologies Inc), above the heart and injecting a bolus of a fluorescent contrast agent intravenously (using the central venous line placed for administration of fluids and drugs). The imaging device emits light at 806 nm causing the contrast agent to fluoresce, emitting light at 830 nm, as it passes through the coronary vessels. The images of the vasculature are captured on a video camera, equipped with an 830 nm bandpass filter, and saved to video tape. The passage of contrast agent through the coronary vasculature can also be observed in real time on a video monitor. Subjects were recruited from patients requiring primary, non-emergent coronary artery bypass surgery. Images of the coronary vasculature were acquired prior to starting the bypass procedure and also upon completion of the procedure, following weaning from bypass pump where appropriate.

RESULTS:

Excellent image quality was achieved permitting visualization of coronary perfusion and venous return over the entire vascular bed being imaged. Images were taken pre-bypass, and after graft completion. This technique permits the rapid (2-3 min) acquisition of high quality images of the coronary vasculature under conditions appropriate to the assessment of graft quality at the time of CABG surgery.

CONCLUSION:

This is the first use of a novel imaging system for intra-operative graft assessment. Use of the technology proved feasible, facile and reproducible in the clinical setting. It is anticipated that this will demonstrate excellent potential in standard bypass grafting as well as with minimally-invasive surgery.