The implication of seniority of supervising attending surgeon on the reexploration rate following elective coronary artery bypass grafting

Background and aims: During coronary artery bypass graft (CABG) surgery, the residual hemostasis procedures, from weaning cardiopulmonary bypass to closing sternotomy, are always completed by residents and supervised by attending surgeons. We want to evaluate the teaching effectiveness for residents under the supervision of attending surgeons with different levels of seniority. Materials and methods: Between January 1st 2001 and December 31st 2010, 2279 consecutive CABG surgeries were performed in our medical center. In total, 83 patients underwent a reexploration for postoperative bleeding. All causes of bleeding were identified and recorded. Competent attending surgeons were defined as having >3 years' experience and young attending surgeons with ≦3 years' experience. We compared the reexploration rate and aimed to identify the common sources of bleeding by the two groups. We also assessed the impact of attending experience on the outcomes and major complications after reexploration. Results: There were 36 surgical bleeding and 17 non-surgical bleeding in the young group and 16 surgical bleeding and 14 non-surgical bleeding in the competent group. The young group experienced more mediastinal drainage before a reexploration and a longer time interval to a reexploration. However, both are without statistical significance. Furthermore, the young group has a significant longer hospital stay. The most common intra-pericardium surgical bleeding included two-stage cannulation, side branch of the left internal mammary artery (LIMA), and side branch of vein grafts. The most common extra-pericardium surgical bleeding included a puncture hole by sternal wires, LIMA bed, and fragile sternum. Conclusion: Young attending surgeons indeed had both higher incidence of reexploration and surgical bleeding after a CABG. However, the supervisor experience only impacted hospital stay, not major complications or mortality after a reexploration. This might imply the competent attending surgeons provide higher teaching effectiveness for the hemostasis procedure after CABG. Keywords: Reexploration, Resident training, Surgeon experience, Cardiac surgery, Coronary artery bypass graftin