Evolution of Bilateral Mammary Arterial Grafting Program in Veterans Affairs Medical Center.

Background: Coronary revascularization with bilateral internal mammary arteries is associated with increased long-term survival, but underutilized due to sternal wound infection concerns. Dedicated bilateral mammary grafting programs are typically high-volume academic or private practices, rather than lower-volume federal institutions whose results are not captured in the Society of Thoracic Surgeons database. Our institution used only single internal mammary arterial grafting in the year prior to implementing a dedicated bilateral grafting program using skeletonized technique. We describe our experience transitioning to bilateral mammary grafting and its impact on sternal wound infection.

Methods: Retrospective cohort study at San Francisco Veterans Affairs Medical Center in 200 patients undergoing first-time isolated, multi-vessel coronary artery bypass from August 2014 to October 2017. Sternal wound infection was defined broadly to include any patient receiving antibiotics for suspicion of sternal infection. Patients were followed for wound complications until 3 post-operative months.

Results: Of 200 total patients, 45.5% (n=91) were diabetic, 44% (n=88) had BMI >30, and 61.5% (n=123) underwent bilateral mammary grafting. Bilateral mammary grafting population had 2.4% (n=3/123) deep sternal wound infection with 1.6% (n=2/123) requiring sternal reconstruction while single mammary population had 1.3% (n=1/77, p=1.0). Bilateral mammary grafting population had 6.5% (n=8/123) superficial sternal wound infection compared to 5.2% (n=4/77, p=0.77) in single mammary grafting population.

Conclusions: Transitioning to high rates of bilateral mammary utilization was possible in a year with low rates of complications. Based on our experience, surgeons should consider adopting a skeletonized bilateral mammary grafting approach given potential long-term survival benefit.