Traumatic Failure of a Left Internal Mammary Artery Graft Following Coronary Artery Bypass Grafting: A Case Report

Traumatic injury to coronary artery bypass grafts is an uncommon but clinically significant cause of recurrent myocardial ischemia after coronary artery bypass grafting (CABG). Internal mammary artery grafts are generally associated with excellent long-term patency; however, blunt chest trauma may result in graft distortion, anastomotic injury, or occlusion. We report a case of a 78-year-old man with hypertension who presented with non-ST elevation myocardial infarction (NSTEMI) and was found to have severe three-vessel coronary artery disease. He underwent uncomplicated three-vessel CABG consisting of left internal mammary artery (LIMA) to left anterior descending artery (LAD), right internal mammary artery (RIMA) to right posterior descending artery (RPDA), and saphenous vein graft (SVG) to obtuse marginal artery (OM). Three months later, he sustained blunt chest trauma after falling from the roof of a shed and subsequently developed exertional angina. Stress myocardial perfusion imaging demonstrated apical ischemia in the LAD territory. Coronary angiography revealed severe stenosis of the distal LIMA-LAD anastomosis and occlusion of the SVG-OM graft. Coronary computed tomography angiography (CCTA) confirmed traumatic distortion of the distal LIMA graft. The patient underwent successful percutaneous coronary intervention (PCI) of the LIMA-LAD graft with overlapping drug-eluting stents (DES) measuring 2.5×38 mm and 2.5×18 mm, as well as PCI of the native circumflex artery with DES implantation. At follow-up, his anginal symptoms had completely resolved. This case highlights blunt chest trauma as a rare mechanism of graft failure following CABG and underscores the role of multimodality imaging and percutaneous revascularization in management.