Ischaemic breast necrosis following coronary artery bypass grafting using left internal mammary artery: understanding the risks.

[BACKGROUND] Coronary artery bypass grafting (CABG) is a common procedure performed commonly using left internal mammary artery (LIMA). We report a case of sternal wound dehiscence and breast necrosis following LIMA harvest in a 55-year-old obese lady with macromastia, diabetes mellitus, hypertension and end stage renal disease requiring dialysis. We also review the existing literature.

[METHODS] Publications were identified from Medline All, Web of Science Core Collection, Google Scholar and Cochrane Central Register of Controlled Trial between 1974 and 2 January 2020. We assessed patient co-morbidities, presentation time frame, quadrant of breast necrosis and reconstruction option utilized.

[RESULTS] There were 18 cases of breast necrosis reported post-CABG. The patients were aged 50 or over, morbidly obese and had large tubular breasts. Other risk factors included chronic renal insufficiency, diabetes and hypertension. The presentation was delayed with necrosis only evident 7 days or more after CABG. All the reported cases had necrosis at lower inner quadrant of the left breast with nipple-areola complex.

[CONCLUSION] Blood supply to the breast is segmental with considerable overlap, however, this overlap is reduced in large breasts. Patients with macromastia and multiple co-morbidities need preoperative imaging (computed tomography angiogram) to evaluate breast vascularity prior to CABG. Risk of breast necrosis needs to be explained during the informed consent. Surgical management of the hypermastia (breast reduction or amputation) may be a factor in facilitating the CABG procedure if indeed the LIMA is absolutely indicated considering the risks and benefits.