Using Intraoperative Coronary Bypass Graft Imaging to Improve Graft Patency

The immediate and long term success of coronary surgery is dependent on the construction of a high quality anastomosis with a durable conduit to an appropriate target coronary vessel. Significant advances in medical therapy including early post-operative aspirin administration and increased use of arterial grafting have improved early, midterm and late graft patency. However, modern coronary bypass series continue to report perioperative graft occlusions rates as high as 11%. These very early graft failures have been predominantly ascribed to technical problems at graft anastomosis sites and may be preventable. New intraoperative graft assessment technologies have recently become available which can identify technical problems such that they can be repaired in the operating room. However, these techniques increase the length of the bypass operation and may have false positives, which may lead to unnecessary and potentially damaging graft revisions. The primary objective of the proposed study is to determine if a strategy of intraoperative patency assessment and graft revision can decrease the rate of graft occlusion or significant stenosis(>50%) at 6-12 weeks after coronary artery bypass grafting (CABG) versus traditional operative management without routine intraoperative patency assessment.

Inclusion criteria

• isolated aortocoronary bypass surgery
• left ventricular ejection fraction >20%
• expect at least 2 bypass grafts

Exclusion criteria

• renal insufficiency (creatinine >180 umol/L)
• known allergy to indocyanine green contrast dye
• severe peripheral vascular disease precluding femoral access
• known allergy to radiographic contrast media
• women of childbearing potential
• co-morbid illness which precludes the use of follow-up angiography
• geographically inaccessible for follow-up angiography