A 55-yr-old male presented with acute chest pain, dyspnea, and hypotension on December 8, 2009. The patient has been followed without any medications for incidentally detected asymptomatic SVC aneurysm for last 2 yr (, and the size of the SVC aneurysm did not change (). Chest radiography at admission showed marked widening of the right middle mediastinum due to abnormal soft-tissue density suggesting the rapid expansion of previously noted SVC aneurysm (). Echocardiography revealed marked enlargement and hypokinesia of the right ventricle (RV) with moderate pulmonary hypertension suggesting acute PE. Chest computed tomographic angiography (CTA) showed about 6.9 × 6.1 × 9.9 cm sized lobulated giant saccular aneurysm originating from mainly SVC and partially involving left brachiocephalic vein with internal thrombi (). Considerable amounts of thromboembolic filling defects in left pulmonary artery, both left and right lobar, segmental, and subsegmental arteries were also noted (). Three-dimensional reconstruction with endovascular views showed the giant saccular SVC aneurysm with 4.1 × 3.7 cm sized internal thrombi, and the thrombi protruded into the SVC through the narrow aneurysmal neck (). Venous CTA of the lower extremities and abdominal CTA showed no evidence of deep vein thrombosis or other venous aneurysms. To exclude the possible hypercoagulable status as a cause of pulmonary thromboembolism, the laboratory tests for hypercoagulability was done and revealed no abnormalities. Surgical exclusion of SVC aneurysm with pulmonary embolectomy was planned, but the patient and family refused surgery. Therefore, thrombolytic therapy using recombinant tissue plasminogen activator with the dose of 200 mg was administered intravenously for 2 hr for hemodynamically significant PTE, and the RV function and pulmonary artery pressure was normalized on FU echocardiography. However, the patient complained recurrent chest pain and dyspnea on the next day. FU CTA revealed more decreased amounts of thrombi in the left pulmonary artery and its branches, but the amounts of thrombi in the SVC aneurysm, SVC, right pulmonary artery and its branches were increased. Mobilization of thrombi from the SVC aneurysm due to thrombolytic therapy was the possible cause of recurrent PTE, and it was expected that further embolization of thrombi would be fatal to the patient. Therefore, surgical treatment was strongly recommended. Resection of SVC aneurysm and pulmonary artery embolectomy were performed successfully. At surgery, femoral arterial and venous cannulation was done to prepare for accidental rupture of aneurysm during sternotomy. After dissection of the aneurysm, the other venous cannulation at the innominate vein and isolation of the proximal and distal portion of the aneurysm was done. Under cardiopulmonary bypass, aneurysmal wall was opened longitudinally after snaring of proximal and distal portion of the aneurysm and innominate vein. Aenurysm which contained fresh thrombi was thin-walled and had relatively normal venous endothelium grossly (), and the histopathologic examination showed compatible findings of true aneurysm (). Thin-walled aneurysmal wall was completely resected and subsequent reconstruction of the superior vena cava was performed with glutaraldehyde fixed autologuous pericardium that was already harvested. Outer surface of the pericardium was buttressed with Dacron to prevent potential formation of pseudoaneurysm. A transverse arteriotomy was made in the pulmonary trunk to the left main pulmonary artery and another incision was made in the right main pulmonary artery, and the fresh and organized thrombi were gently extracted. Following the successful surgical management, the mediastinal widening on chest radiography was normalized () and the patient was recovered without any postoperative events. The patient was discharged and treated by anticoagulation with warfarin for 6 months to achieve complete resolution of the possible remained pulmonary arterial thrombi.
A 52-year-old male patient was admitted to the hospital due to an irritating cough for more than 1 month. He had no recent history of chest trauma surgery or respiratory diseases. A chest CT scan showed anterior mediastinal space, and showed differential diagnosis of teratoma, thymoma and lymphomas, in order to clarify the relationship between the space-occupying lesions and blood vessels and surrounding tissues, a chest-enhanced CT examination was performed. After intravenous injection of contrast medium, a dual-phase scan was performed. It was found that there was a localized aneurysm-like expansion in the left brachiocephalic vein and its diameter was 5.2 cm with the smooth edge (Fig. ), which confirmed the diagnosis of venous aneurysm. After careful evaluation of the patient, surgery was performed.\nA median sternum incision was selected in the surgery. During the operation, a huge aneurysm is found to be located in front of the left brachiocephalic vein. The aneurysm and surrounding tissues were carefully separated to prevent uncontrollable bleeding during the process, and to mechanical damage caused by extracorporeal circulation. We first performed heparinization of the whole body blood, and blocked both ends of the brachiocephalic vein, separated the fibrous membrane of the venous blood vessel, and found that the aneurysm wall was thin. The aneurysm was cystic expansion, and there as a larger aneurysm neck connected to it. After the aneurysm was removed, a double-layer continuous suture with 5–0 prolene thread was used to suture the brachiocephalic vein. We paid attention to the shape of the normal brachiocephalic vein during the suture process. To prevent vascular distortion and lumen stenosis, we carefully loosened the blocking bands at both ends before knotting, determined the shape of the formed blood vessel, and expelled the possible air (Fig. ). After confirming that there is no obvious active bleeding, heparin was neutralized with protamine, and the operation ended after the sternum is fixed by the wire.\nThe mediastinal drainage tube was removed on the third day after the operation, and the patient was discharged from the hospital 2 days later. Postoperative pathology showed that the specimen was thinned venous wall tissue (Fig. ). He was followed up for 6 months, and there was no obvious abnormality in the chest enhanced CT, with good recovery.