Complex Coronary Artery Bypass Grafting: A Safe Concept for Surgical Training

Objectives: Recent studies have revealed advantages of coronary artery bypass grafting (CABG) using aortic-no touch techniques. However, these techniques demand complex CABG methods, such as composite and sequential grafting. So far, no standard guidelines concerning surgical training in bypass grafting in terms of graft choice exist. For residents at our institution we follow the strategy to start with complete arterial revascularization under supervision of an experienced surgeon from the beginning of surgical training.

Methods: From 01/2017 to 07/2019, a total of 672 consecutive patients were referred for isolated CABG to our institution. CABG without cardiopulmonary bypass, single bypass grafting, and aortocoronary cases were excluded. All CABG referrals were evaluated by an experienced CABG surgeon and then selected by coronary morphology for group 1 (experienced surgeons) or group 2 (residents in training). Thirty-day outcomes of group 1 (n = 202) and group 2 (n = 470) were compared.

Result: Age was similar in both groups (group 1: 65.0 ± 10.0 vs. group 2: 64.0 ± 9.8 years; p = 0.24). Logistic EuroSCORE I was significantly higher in group 1 (2.0 ± 2.9 vs. 1.5 ± 1.1%; p < 0.001). Number of patients with three vessel disease was 92.6% in group 1 and 55.1% in group 2 (p < 0.001). Further preoperative variables demonstrated no significant differences. Procedure, extracorporal circulation, and aortic cross-clamp time were significantly higher in group 1 (349 ± 85.5 vs. 315 ± 69.0 minutes; p < 0.001; 141 ± 48.5 vs. 109.2 ± 35.0 minutes; p < 0.001; 99 ± 15.0 vs. 70 ± 27.1 minutes; p < 0.001). Number of anastomoses was significantly higher in group 1 (3.0 ± 0.4 vs. 2.2 ± 0.5; p < 0.001). Use of bilateral internal mammary artery (BIMA) was 55.5% in group 1 and 84.7% in group 2 (p < 0.001). At 30-day follow-up, there were no significant differences in rates of all-cause mortality (1.5 vs. 0.9%; p = 0.43), postoperative myocardial infarction (1.5 vs. 1.7%; p = 1.0), and acute renal failure (1.0 vs. 0.2%; p = 0.22) between groups. No major stroke occurred during follow-up.

Conclusion: Acute outcomes after complex arterial CABG performed by residents were not inferior compared with experienced surgeons even though direct comparability is hampered by more pronounced risk profile and more extensive surgery in group 1. Complex revascularization by residents in training under supervision was safely performed with satisfying results. Selection of lower-risk patients requiring less anastomoses allows for training of complex coronary surgery with adequate safety for patients and high proportion of BIMA use.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
19 February 2021