Giant saphenous vein graft pseudoaneurysm to right posterior descending artery presenting with superior vena cava syndrome

Abstract

Saphenous vein grafts (SVG) pseudoaneurysms, especially giant ones, are rare and occur as a late complication of coronary artery bypass grafting. This condition affects both genders and typically occurs within the sixth decade of life. The clinical presentation ranges from an asymptomatic incidental finding on imaging studies to new onset angina, dyspnea, myocardial infarction or symptoms related to compression of neighboring structures. An 82-year-old woman presented with acute onset back pain, dyspnea and was noted to have significantly engorged neck veins. In the emergency department, a chest computed tomographic angiogram with intravenous contrast revealed a ruptured giant bilobed SVG pseudoaneurysm to the right posterior descending artery (RPDA). This imaging modality also demonstrated compression of the superior vena cava (SVC) by the SVG pseudoaneurysm. Coronary angiogram with bypass study was performed to establish the patency of this graft. Endovascular coiling and embolization of the SVG to RPDA was initially considered but disfavored after the coronary angiogram revealed preserved flow from the graft to this arterial branch. After reviewing the angiogram films, a surgical strategy was favored over a percutaneous intervention with a Nitinol self-expanding stent since the latter would have not addressed the superior vena cava compression caused by the giant pseudoaneurysm. Intraoperative transesophageal echocardiogram demonstrated SVC compression by the giant pseudoaneurysm cranial lobe. Our patient underwent surgical ligation and excision of the giant pseudoaneurysm and the RPDA was regrafted successfully. In summary, saphenous vein grafts pseudoaneurysms can be life-threatening and its therapy should be guided based on the presence of mechanical complications, the patency of the affected vein graft and the involved myocardial territory viability.

Keywords: Giant saphenous graft pseudoaneurysm; Late complication of coronary artery bypass grafting; Superior vena cava syndrome; Endovascular coiling and embolization; Nitinol self-expanding stent

Core tip: Saphenous vein grafts (SVG) pseudoaneurysms, especially giant ones, are rare and occur as a late complication of coronary artery bypass grafting. Although unusual, superior vena cava (SVC) syndrome has been reported as a complication of saphenous vein graft pseudoaneurysms causing compression of the SVC. Here we report a case of such condition illustrated with state-of-the-art multi-modality images which were critical for the planning of the most appropriate treatment strategy. SVG pseudoaneurysms can be life-threatening and their therapy should be guided based on the presence of mechanical complications, the patency of the affected vein graft and the involved myocardial territory viability.