Left Internal Mammary Artery Skeletonization Reduces Bleeding-A Randomized Controlled Trial.

ABSTRACT

BACKGROUND: The objective of this study was to compare the impact of skeletonized versus pedicled left internal mammary artery (LIMA) harvesting on bleeding after coronary artery bypass grafting (CABG). METHODS: In a randomized, single-blinded trial with a parallel group design and equal allocation, we randomly assigned 62 patients undergoing primary elective CABG in a tertiary cardiac center to skeletonized or pedicled LIMA dissection. Before surgery, all aspects of coagulation were assessed. Patients were blinded to LIMA dissection technique and monitored for cumulative drainage at 12 hours (primary outcome) as well as myocardial necrosis markers. RESULTS: With recruitment complete, there were 31 patients in each group; all patients were analyzed. Median postoperative drainage was 395 mL at 12 hours in all patients; it was lower by 28% at 12 hours (P = .02) in patients with skeletonized LIMA (Cohen's d, 0.6; 95% confidence interval (CI), 0.09-1.11). Patients with a LIMA pedicle received more fresh-frozen plasma transfusions than did the skeletonized LIMA group (Median 3; interquartile range 3-5 versus median 3; interquartile range 3-3; P = .03). Study arms did not differ in blood coagulation. Left internal mammary artery skeletonization (odds ratio = 0.04; 95% CI, 0.003-0.44; P = .009) and higher body mass index (odds ratio = 0.63; 95% CI, 0.45-0.89; P = .008) decreased the odds of being in the top drainage quartile at 12 hours (≥550 mL). Creatine kinase was lower in skeletonized LIMA directly after surgery (median 218 U/L; interquartile range 175-310 U/L versus median 424 U/L; interquartile range 256-510 U/L; P < .001), at 6 hours (median 324 U/L; interquartile range 239-424 U/L versus median 529 U/L; interquartile range 374-707 U/L; P < .001), and 12 hours after surgery (median 351 U/L; interquartile range 277-552 U/L versus median 695 U/L; interquartile range 509-1067 U/L; P < .001). CONCLUSIONS: Left internal mammary artery skeletonization results in lower mediastinal drainage after CABG than pedicled LIMA harvesting.