A 45-year-old male was diagnosed with an anterior mediastinal tumor and referred to our hospital. Open biopsy results of the tumor revealed a squamous cell carcinoma and cytology findings were positive for pericardial effusion. Chest computed tomography (CT) showed a mass approximately 10 cm in size with invasion to the left hilar part of the left lung and aortic arch, as well as pericardial effusion (Fig. 1A-C), thus the patient was diagnosed with a thymic carcinoma, c-Stage IVa (cT4N0M1a). Six courses of chemotherapy with carboplatin and paclitaxel were performed, followed by S-1 administration for 1 year. The results included disappearance of pericardial effusion and slightly decreased tumor size in chest CT findings (Fig. 1D-F), while fluorodeoxyglucose (FDG)-position emission tomography also revealed that FDG uptake was decreased after the chemotherapy regimen (Fig. 2). However, at this time the patient was affected by liver dysfunction due to chemotherapy, thus we considered surgical options because that administration could not be continued.
A left lateral thoracotomy was initially performed and the findings ruled out pleural or pericardial dissemination, thus a median sternotomy was added. The tumor was suspected to have invaded the main pulmonary artery (PA) trunk as well as aortic arch. The left brachiocephalic vein showed obvious tumor invasion and was dissected, though the mass could not be divided from the aorta. Moreover, the left PA could not be encircled in the pericardium. Following systemic heparinization (300 U/kg), a cardiopulmonary bypass (CPB) was established with right atrium drainage, as well as 2 points of arterial perfusion via the femoral and right axillary arteries. The shrunken left main trunk of the PA was then dissected and divided with a stapler, and the upper and lower pulmonary veins, and left main bronchus were also divided. Finally, the tumor was sharply separated from the aorta and removed along with the left lung. Although the mass was removed from the wall of the aortic arch, some tumor residue remained on that wall, thus residual tumor resection with replacement of the aortic arch using total rerouting of the supra-arch vessels (3) was performed. Anastomoses of the ascending aorta and trunk of the trifurcation graft (Hemashield three-branch graft, 12-8-8 mm) were performed with side-clamping, and subsequently the brachiocephalic artery, left common carotid artery, and left subclavian artery were reconstructed one by one with simple clamping method. Next, after clamping the ascending aorta just distal to the trifurcated graft inflow anastomosis and proximal descending aorta, the aortic arch was resected with the residual tumor and reconstructed using a 26-mm graft. Cardiac arrest was not introduced during the whole procedure, however CPB could not be weaned off because of right heart failure caused by PA bifurcation stenosis. Therefore, we reconstructed the PA bifurcation, which stenosis was due to division line of left PA being too close to PA trunk, using an 18-mm tube graft (Fig. 3) by replacing PA trunk and right PA. After the repair of PA, CPB was weaned off uneventfully. The operative time was 958 minutes and CPB time was 254 minutes, while blood loss was 7980 ml. The patient was extubated on postoperative day (POD) 2 and the postoperative course was uneventful. He was discharged on POD 42 and free from recurrence at 3 years after the operation.