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

Abstract

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) post-operative 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 two study cohorts. From 546 off-pump CABG patients initially identified, we examined 328 BIMA and 213 SIMA grafts from the matched samples. Despite utilizing 60.4% BIMA grafts, we observed similar rates of 30-day overall and cardiac mortality between the BIMA and SIMA groups. 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 two groups. Rates of 30-day overall and cardiac readmission were also similar. Additionally, median length of hospital stays, intensive care unit stay, and ventilation times were similar between the two groups. In conclusion, our data suggest that a BIMA utilization rate of 60.4% in off-pump CABG procedure is achievable without causing any significant increment in early post-operative complications, including deep sternal wound infection.