The Use of Bilateral Internal Mammary Artery Grafting in Different Degrees of Obesity

Background Obesity is a limiting factor for the use of bilateral internal mammary arteries (BIMAs). Therefore, we assessed the safety of their use in different degrees of obesity. Patients and Methods We studied two groups of patients with obesity using propensity matching. The first group received single internal mammary artery and saphenous vein grafts (SIMA group, 526 patients) and the second group received bilateral internal mammary arteries (BIMA group, 526 patients). Patients were classified further according to their body mass index (BMI) into overweight (BMI = 25-29.9 kg/m²), obese (BMI = 30-34.9 kg/m²), and severely obese (BMI ≥ 35 kg/m²). Results Preoperative data were similar regarding age (62.78 ± 9.96 vs. 62.98 ± 9.66 years; p = 0.734), female sex (17.5 vs. 18.6%; p = 0.631), diabetes mellitus (26.3 vs. 27.2%; p = 0.74), EuroSCORE (3.21 ± 2.23 vs. 3.18 ± 2.41; p = 0.968), and COPD (16 vs. 16%; p = 1). No significant differences were noticed between the two groups regarding the number of peripheral anastomoses (3.09 ± 0.84 vs. 3.12 ± 0.83; p = 0.633), myocardial infarction (1.7 vs. 1.7%; p = 1), reexploration (1.3 vs. 2.1%; p = 0.34), deep sternal wound infection (DSWI) (2.1 vs. 2.9%; p = 0.43), and 30-day mortality (0.8 vs. 1.1%; p = 0.53). Multivariate analysis identified BMI and intensive care unit stay as independent predictors for DSWI. However, postoperative blood loss (694.56 ± 631.84 vs. 811.67 ± 688.73 mL; p < 0.001) and the incidence of pneumothorax (1 vs. 2.7%; p = 0.037) were higher in BIMA group. Conclusion Patients with obesity can benefit from BIMA grafting. However, postoperative blood loss and the incidence of pneumothorax can be higher using this technique.