Sternal healing after bilateral internal mammary arteries use for Coronary artery bypass grafting in diabetic Patients; short-term results

Background:  Bilateral internal mammary artery (BIMA) use may improve long-term outcomes after coronary artery bypass grafting (CABG); however, the risk of infection is high.   Skeletonization of the internal mammary may decrease the risk of infection, especially in patients with diabetes. Our study aimed at evaluation of sternal healing in diabetic patients with different techniques of bilateral internal mammary artery harvesting. Methods: This prospective randomized study included 200 diabetic patients who underwent CABG using BIMA between 2017 and 2019. We divided patients into two groups; Group A had skeletonization of both internal mammary arteries, and Group B had pedicled left mammary and skeletonized right mammary. Patients were observed for three months, post-operatively for any sternal wound problems. Results: There was no significant difference regarding the baseline variables. Type I diabetes mellitus was present in 25% in group A (n= 24) and 13.64% in group B (n= 12) (p= 0.324). There was no difference in harvest time between groups (83 ±4 vs. 81 ±3 minutes in group A vs. B, respectively. P= 0.1). The mean number of grafts was 3± 0.5 in Group A and 3± 0.6 in Group B (p= 0.8). Postoperative drainage was 402.9 ± 174.1 ml in Group A vs. 387.2 ± 153.6 ml in Group B (p= 0.474). The duration of ICU stay did not differ significantly between groups (2± 0.7 in Group A vs. 2± 0.5 in Group B; p= 0.8). Deep sternal wound infection occurred in 4.17% in group A (n= 4) and 4.55% in group B (n= 4) (p= 0.705). Superficial wound infection occurred in eight patients in group A (8.33%) and eight patients in group B (9.1%) (p= 0.59). No patient had sternal dehiscence in group A vs. four patients in group B (4.55%) (p= 0.39). Conclusion: We did not find differences between bilateral mammary artery harvest with skeletonization of both arteries versus skeletonization of the right mammary only on sternal healing nor wound infection in diabetic patients undergoing CABG. A larger study is recommended.