Photochemical Tissue Passivation Treatment of Saphenous Vein Grafts in CABG

Inclusion Criteria: 1. Signed informed consent, inclusive of release of medical information, and Health Insurance Portability and Accountability Act (HIPAA) documentation. 2. Age 21 years or older. 3. Planned and scheduled on-pump, arrested heart CABG. 4. Two or more vein grafts to native vessels having at least 75% stenosis and comparable runoff. 5. IMA graft indicated for the LAD. 6. Appropriately sized and accessible target coronary arteries, with a minimum diameter of 2 mm and adequate vascular bed (without significant distal stenosis), as assessed by pre-operative cardiac angiography and verified by diameter gauging intraoperatively. \- Exclusion Criteria: 1. Concomitant non-CABG cardiac surgical procedure. 2. Prior cardiac surgery. 3. Emergency CABG surgery (e.g., cardiogenic shock, inotropic pressure support, intraaortic balloon pump, ECMO). 4. Contraindication for on-pump CABG with cardioplegic arrest (e.g., severely calcified aorta). 5. Calcification at the intended anastomotic sites, as assessed upon opening of the chest and before randomization. 6. Platelets \< 50,000/mm3 or other evidence of coagulopathy, INR greater than 1.5 in the absence of anticoagulation therapy. 7. Infection (WBC ≥12.5 x 103/ml and or temperature ≥100.5°F/38°C). 8. History of cerebral vascular accident (CVA) or transient ischemic attacks (TIA) within the last 3 months. 9. Unwilling or unable to receive blood transfusion. 10. Inability to undergo treatment with heparin. 11. Participants on dialysis or GFR of \<30 ml/min/1.73m2. 12. Primary liver disease with bilirubin, SGOT, or SGPT \> 4X upper limit of normal. 13. Prior history of allergic reaction to contrast media with anaphylaxis or severe peripheral edema. 14. Any medical condition that, in the opinion of the investigator, would compromise the safety of the participant or quality of the study data. 15. Pregnancy and nursing or lactating. 16. Current, or past participation in a clinical trial within the past 30 days.