Real-time multispectral imaging for intraoperative monitoring of coronary artery bypass graft patency.

Significance: Coronary artery disease is the leading cause of death worldwide, accounting for 16% of all deaths. A common treatment is coronary artery bypass grafting (CABG), though up to 12% of bypass grafts fail during surgery. Early detection of graft failure by intraoperative graft patency assessment could prevent severe complications.

Aim: We aim to evaluate multispectral imaging (MSI) as a non-invasive, contrast-free method for assessing graft patency during CABG surgery.

Approach: MSI was conducted at video rate during three CABG surgeries and two control surgeries. Two multispectral snapshot cameras captured images in the visible and near-infrared range. Tissue oxygenation and perfusion were derived using linear spectral unmixing and spectral indices.

Results: Significant increases in both oxygenation ( $12.22\pm 10.24\%$ , $p<0.001$ ) and perfusion index ( $4.50\pm 1.79$ , $p<0.001$ ) were observed after CABG, with no significant changes in control surgeries (oxygenation: $-0.36\pm 2.57\%$ , $p=0.041$ ; perfusion: $0.41\pm 1.33$ , $p=0.482$ ). These findings demonstrate the ability of MSI to indicate graft patency, in which the bypass graft restores oxygen-rich blood flow.

Conclusions: MSI could offer a valuable tool for surgeons, helping to reduce the risk of graft failure and improve patient outcomes.