Risks and Outcomes of Reoperative Cardiac Surgery in Patients With Patent Bilateral Internal Thoracic Artery Grafts

Background: Reoperative cardiac surgery in patients with patent bilateral internal thoracic artery (ITA) grafts is technically challenging. Methods: From 2008 to 2017, of 7640 patients undergoing reoperative cardiac surgery, 116 (1.5%) had patent bilateral ITA grafts, including 28 with a right ITA crossing the midline. Mean age was 70 ± 9.6 years, and 111 patients (96%) were men. Reoperations included isolated coronary artery bypass grafting (n = 11), isolated valve (n = 55), valve + coronary artery bypass grafting (n = 26), and other procedures (n = 24). Clinical details, intraoperative management, and perioperative outcomes were analyzed. Results: Aortic cannulation was central in 64 patients (56%) and through the femoral or axillary artery in 50 (44%). Four patients (3.4%) had planned transection and reattachment of ITAs crossing the midline, and 4 (3.4%) had ITA injuries, all right ITAs, 3 crossing the midline; 3 were repaired with an interposition vein graft, and 1 was managed by translocating the right ITA as a Y-graft off another graft. Patent ITAs were managed by atraumatic occlusion during aortic clamping in 90 patients (78%) and by systemic cooling without ITA occlusion in 19. There were 6 operative deaths, all due to low cardiac output syndrome (5.2%); 4 strokes (3.4%); and 5 cases of new postoperative dialysis (4.3%). Conclusions: Risk of injury to bilateral ITA grafts during reoperation is high, and right ITAs crossing the midline present a particular risk of injury and should inform planning for primary coronary artery bypass grafting. Risk of low cardiac output syndrome underscores the challenge of ensuring adequate myocardial protection.