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 42-year-old female was referred to the outpatient department, with features suggestive of lower respiratory tract infection. Physical examination was unremarkable. She had no history of any cardiac disease or injury to thoracic cage. She had no history of antecedent serious illness. Family history was also non-contributory.\nChest X-ray was done for the workup of respiratory symptoms, which showed abnormal contour and widening of right border of mediastinum (). In chest X-ray, the cervico-thoracic sign and hilum overlay sign were present in posteroanterior (PA) view. Lateral view showed anterior bulging of mediastinum.\nComputed tomography (CT) of thorax was done for further workup in angiographic protocol which was suggestive of aneurysmal ectasia of SVC and patchy consolidation of right lower lobe. Aneurysmal ectasia of SVC measuring 4.5 × 5.5 cm in maximum dilatation and for a length of 8.9 cm without internal thrombosis or dissecting flap was present ( and ). No other vascular anomalies were detected.\nSince CT did not reveal any signs of obstruction, we believe that the SVC aneurysm is primary and can be classified as congenital primary superior vena caval aneurysm (CPSVCA), class 1A as per Abott’s classification (1964) [].