Predominant Use of Bilateral Internal Mammary Arteries in Off-Pump Coronary Artery Bypass Surgery

Bilateral internal mammary artery (BIMA) in coronary artery bypass grafting (CABG) has been shown to provide long-term clinical benefits over single internal mammary artery (SIMA) grafting. Nevertheless, the perceived technical complexity of the procedure and concerns about potential early postoperative complications, particularly, sternal wound infections, have led to a utilization rate of BIMA grafting of less than 5% in the United States. We systematically compared early (30-day) postoperative outcomes between the BIMA and SIMA cohorts in patients with similar baseline characteristics. A retrospective single-center study was conducted on matched patients, using stabilized inverse probability treatment weighting to mitigate bias between the 2 study cohorts. From 546 patients who underwent off-pump CABG initially identified, we examined 328 BIMA and 213 SIMA grafts from the matched samples. Despite using 60.4% BIMA grafts, we observed similar rates of 30-day overall and cardiac mortality between the BIMA and SIMA groups. The rates of 30-day postoperative complications, including superficial and deep sternal wound infections, stroke, sepsis, acute kidney injury, and cardiac arrest, were similar between the 2 groups. The rates of 30-day overall and cardiac readmission were also similar. In addition, the median length of hospital stays, intensive care unit stay, and ventilation times were similar between the 2 groups. In conclusion, our data suggest that a BIMA utilization rate of 60.4% in off-pump CABG procedures is achievable without causing any significant increment in early postoperative complications, including deep sternal wound infection.