Skeletonized versus pedicled left internal mammary artery harvesting and risk of sternal wound infection after coronary artery bypass surgery

Abstract

Background: The left internal mammary artery (LIMA) is the gold standard conduit for coronary artery bypass grafting (CABG). There are two harvesting methods, either pedicled or skeletonized. The choice of any technique must consider its complication profile, especially sternal wound infections (SWI). This study aims to evaluate and compare the occurrence of SWI after pedicled and skeletonized LIMA harvesting techniques for CABG.
 Methods: This prospective observational study included 300 patients who had CABG between 2016 and 2019. We included patients who had pedicled LIMA (n=200) in group 1 and who had skeletonized LIMA (n=100) in group 2. All patients completed a follow-up period of 3 months after CABG. The evaluation during follow-up included: sternal instability, signs of wound infection, temperature, the microbiological study of wound discharge, and chest computed tomography scan.
 Results: There was no significant differences in age (p = 0.20), male to female ratio (p = 0.43), body mass index (p = 0.12), NYHA I/II (p = 0.50), diabetes mellitus (p = 0.28), ejection fraction (p= 0.14), and EuroSCORE II (p= 0.09) between groups. No significant difference in cardiopulmonary bypass time (p = 0.24), and cross-clamp time (p= 0.19) between groups. There was a significant increase in the total operating time in skeletonized LIMA group (212.77±75.25 min vs. 190.78±55 minutes, p= 0.004). Skeletonized LIMA was significantly associated lower incidence of SWI than that with pedicled LIMA (4% vs 15.5%, p= 0.003), and non-significantly lower incidence of deep SWI (1% vs 4.5%, p= 0.11). The risk factors for SWI in patients who had pedicled IMA were obesity (OR: 13.06, 95%CI: 3.98-42.89), diabetes mellitus (OR: 10.51, 95%CI: 2.35-46.84), and excessive diathermy (OR: 12.62, 95%CI: 3.93-40.54).
 Conclusion: Obesity, diabetes, and the use of excessive diathermy for hemostasis may increase the risk of sternal wound infection with pedicled LIMA harvest compared to skeletonized LIMA in patients undergoing CABG.