Case Description
A 70-year-old man presented with dyspnea on effort and lower limb edema. Chest radiography showed cardiomegaly (cardiothoracic ratio of 57%). Transthoracic echocardiography showed a huge mass measuring 44 × 56 mm originating from the right atrium and right ventricle. The mass was almost completely adhered to the tricuspid valve, resulting in moderate stenosis with a mean pressure gradient of 9 mmHg (Video 1). Enhanced computed tomography showed that the tumor had invaded the anterior wall of the right atrium and right ventricle, totally involving the right coronary artery (Figure 1A, B). The interleukin-2 receptor level was extremely high (890 U/mL). Fluorodeoxyglucose positron emission tomography revealed abnormal accumulation in the right atrium, right ventricle, atrial septum near the mitral valve annulus, and intestinal and prepericardial lymph nodes (Figure 2).
Cardiopulmonary bypass was established through ascending aortic cannulation and bicaval drainage, and the heart was arrested. The tumor had invaded the anterior and posterior tricuspid annulus, but not the septal leaflet or coronary sinus. We performed complete en bloc resection of the tumor and most of the right atrium, right ventricle, tricuspid valve, and right coronary artery, preserving the coronary sinus. The tricuspid septal annulus was also preserved, and we applied several everting mattress stitches for placement of a biological valve. A large double-folded bovine pericardial patch was then sutured to the remaining biological cuff; one side of the patch was trimmed and sutured to the right ventricle, while the other side was sutured to the right atrium. Finally, coronary bypass was performed from the great saphenous vein to the posterior descending artery (Video 2). No atrioventricular block was present postoperatively. The operation, cardiopulmonary bypass, and cross-clamping times were 332, 175, and 121 minutes, respectively. Pathological examination revealed diffuse large B-cell lymphoma.
Postoperative transthoracic echocardiography revealed no tumor or thrombus and showed good performance of the biological valve with a mean pressure gradient of 5 mmHg (Video 1). Postoperative enhanced computed tomography showed a well-reorganized right atrium and right ventricle. The patient was discharged on postoperative day 14 with no signs of heart failure. Although the excised end of the tumor was pathologically positive, the patient was able to receive optimal chemotherapy because an accurate qualitative diagnosis had been obtained by surgery. The chemotherapy resulted in a partial response at 6 months postoperatively.