Coronary artery bypass grafting using both internal mammary arteries-a safe concept for surgical training

In our centre, a bilateral internal mammary artery first approach is established from day 1 of surgical training. We herein aimed to investigate safety and clinical efficacy of this training concept.

All patients undergoing isolated bypass grafting between 2009 and 2021 at our institution were included in this study. Patients provided with single mammary artery, radial artery or vein grafts were excluded. According to a preoperative evaluation conducted by experienced coronary bypass surgeons, coronary artery disease severity was classified, and patients were allocated to group 1 (surgery performed by staff surgeons) and group 2 (surgery performed by residents under supervision of staff surgeons). Thirty-day outcome parameters were compared between groups.

A total of 2125 patients were allocated to group 1, and 431 patients were assigned to group 2. Patients in group 1 presented a higher risk profile. Coronary artery bypass grafting in group 2 was more often performed as on-pump procedure with a longer procedure duration. Number of performed bypasses was lower in group 2 with fewer composite grafting and fewer anastomoses to the RCA territory. No significant differences in 30-day all-cause mortality, myocardial infarction, stroke or acute kidney injury were seen.

Thirty-day outcomes after coronary artery bypass grafting using bilateral internal mammary artery grafts performed by residents were without significant differences to outcomes of staff surgeons, suggesting that application of both internal mammary arteries by residents is safe and effective when performed under supervision and after preoperative patient screening.