An Uncommon Complication of Nondissected Ascending Aortic Aneurysm
An 86-year-old woman was admitted with a 2-week-long history of increasing dyspnea. She had an ascending thoracic aortic aneurysm (8×9 cm) diagnosed 5 years before. On admission, the patient was in moderate respiratory distress. Her vital signs were blood pressure 130/80, heart rate 72 bpm (irregular), respiration rate 32 rpm, and temperature 36°C. Chest auscultation revealed decreased breath sounds at right base. The ECG showed atrial fibrillation. Basic laboratory data were unremarkable. Chest x-ray findings are shown in Figure 1. The echocardiogram revealed a nonenlarged left ventricle. Thoracocentesis yielded a pleural fluid with characteristics of transsudate. A thoracic CT scan confirmed that aortic aneurysm had been enlarged (9.5×10 cm), extended posteriorly, and severely compressed the right pulmonary vessels and left atrium, causing a massive right pleural effusion and pulmonary collapse without dissection, rupture, or pericardial effusion (Figures 2 and 3⇓). The treatment was conservative because of the high risk involved.
Thoracic aortic aneurysms enlarging as mediastinal masses are associated by compression or by rupture with a number of ischemic and mechanical complications. A large midline aneurysm of the ascending aorta may compress the pulmonary vessels, usually causing pulmonary venous hypertension and pulmonary edema. This patient represents an extremely unusual case of unilateral transudative pleural effusion caused by compression of pulmonary vessels by a large, nondissected aneurysm of the ascending aorta.