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 50-year-old female patient presented with the incidental finding of an anterior mediastinal mass on chest radiography during a routine health examination in October 2020. No related subjective symptoms were reported and the physical examination showed no abnormalities. Contrast-enhanced computerized tomography (CT) of the chest showed a 4.8 × 4.6 cm anterior mediastinal mass with significant homogenous enhancement after injection of the contrast (mean CT values before and after contrast injection were 38 and 115 HU, respectively), suggesting a diagnosis of Castleman's disease, but not excluding thymoma ().\nThe patient underwent surgical resection of the anterior mediastinal mass under a thoracoscopic approach. After the intubation of the single lumen tube with a bronchial obstruction balloon, single lung ventilation on the contralateral side was performed under general anesthesia. The patient was placed in the lateral position with a retroversion of 30°. The operation was performed via a single-utility port: the endoscopic port was a 1-cm incision at the 6th intercostal space in the midclavicular line, and the utility port was a 3-cm incision at the 4th intercostal space along the anterior axillary line. Intraoperatively, the anterior mediastinal mass was determined to be an aneurysm originating from the left innominate vein. Through careful surgical manipulations and adequate exposure of the operative field, the root of the aneurysm was fully dissected and ligated, and then the root vessel was divided with a cutter closure (). Postoperative pathology confirmed the diagnosis of left innominate vein aneurysm. The patient experienced an uneventful postoperative course. The thoracic drainage tube was removed on postoperative day 1 after chest X-ray imaging showed complete re-expansion of the lung, with no obvious pneumothorax or hydrothorax. She was discharged from the hospital on postoperative day 2. At her 6-month follow-up, the patient did not report any specific discomfort.