Severe Functional Tricuspid Stenosis Secondary to a Giant Saphenous Vein Bypass Graft Aneurysm

A 75-year-old man presented with dyspnea requiring home oxygen, on a background of partial colectomy for colon cancer, chronic renal failure, and coronary artery bypass graft surgery in 1978 (left internal mammary artery to left anterior descending graft and saphenous vein grafts [SVG] to the right coronary artery [RCA] and left circumflex artery). Clinically, he had jugular venous distension and bibasal crepitations, without overt ascites or peripheral edema. Chest x-ray demonstrated remote postoperative changes, cardiomegaly, mild pericardial calcification, and other radiographic findings of congestive heart failure, without apparent mediastinal mass (Figure 1). However, echocardiography revealed a large (9.4×8.7 cm), apparently extracardiac, mass compressing the right ventricle with severe functional tricuspid stenosis (mean gradient, 10 mm Hg) and turbulence of forward transtricuspid flow on color Doppler imaging (Figures 2A, 2B, and 3; Movie IA and IB in the online-only Data Supplement). Noncontrast cardiac MRI revealed a large (10.9×7.4×6.5 cm), relatively homogenous structure adjacent to the atrioventricular groove anteriorly, which was compressing the right heart and obstructing the tricuspid valve. The mass was distinct from adipose tissue, well circumscribed by overlying pericardium, and had no invasive characteristics. Cine imaging demonstrated flow within the mass. The structure location and characteristics were consistent with a partially thrombosed SVG aneurysm (Figure 4; Movie II …