Porcine Dermal Collagen (Permacol) for Sternal Reconstruction
A 63-year-old male visited the hospital for chest pain. A simple chest radiologic examination suggested an anterior mediastinum tumor. Other than the chest pain, the patient did not show myasthenia gravis or any other notable symptoms on physical examination. A chest computed tomography (CT) showed a 6.8 cm tumor at the anterior mediastinum (). The tumor seemed to cover the left innominate vein and invade the thoracic wall. This tumor had invaded the sternum, left side of the parasternal area, ribs, and intercostal muscles. Based on the positron emission tomography--CT results, hypermetabolic uptake lesions were noted at the main mass and lymph nodes of the 3rd and 4th left costal bones and paratracheal area. Accordingly, preoperative percutaneous needle biopsy was executed for the main mass, and the result came out as thymic carcinoma with the possibility of squamous cell carcinoma.\nFive cycles of neoadjuvant chemotherapy (paclitaxel+cisplatin) were followed. After chemotherapy for three months, the tumor size seemed to have increased, but did not show any other metastasis according to the other test results. Considering the patient and disease status, surgical treatment was planned.\nAfter general anesthesia, a single-lumen endotracheal tube was inserted and the operation proceeded in the supine position. After a median skin incision, the mass invading the chest wall was observed. Thus, undermining of both subcutaneous layers and muscle layers was performed in order to determine the invasion range. In addition, extensive resection procuring the tumor margin was performed at the sternal body and 2nd through 5th intercostal rib cartilages using an oscillating saw and rib cutter (). The tumor not only had invaded the sternum and both chest walls, but had also invaded the left jugular vein and the brachiocephalic vein, which were shrunken due to the tumor and had adhered to the left upper lobe. Hence, after saving and detachment of the left phrenic nerve, division at the superior vena cava-innominate vein junction and left jugular vein proximal area was performed by vascular endo-GIA. Despite the obstruction of the innominate vein and left jugular vein, symptoms such as left arm and facial swelling did not appear preoperatively. Therefore, only vascular resection without reconstruction was done, and no such symptoms were noted postoperatively. Tumor invasion to both lungs was also found. Therefore, both pleurae were opened, and wedge resections of the right and left upper lobes were performed using GIA staplers. Since the tumor was also abutting the aortic arch, the parietal pericardium was opened and the tumor was cautiously detached and removed from the aortic wall ().\nThe sternum and chest wall defect was wide and chest wall reconstruction using a Permacol patch (20×15 cm) was planned. The margin of the defect was calculated as stated in , and was tailored based on the shape of the defect. Using steel wire for the upper margin, suture of the manubrium and a tailored patch were performed. The tailored patch was anchored at the lateral margins of the bilateral ribs and the lower margin with multiple intermittent sutures using 1/0 polypropylene. Finally, the chest wall reconstruction was completed ().\nPostoperative pathological examination confirmed that the tumor was thymic carcinoma (large-cell neuroendocrine carcinoma). Despite a normal appearance on intraoperative gross examination, the resection margins of the superior, medial, and lateral areas showed tumor involvement. In addition, metastasis to one lymph node (LN11) was confirmed.\nThe patient was transferred to the intensive care unit after the surgery, was extubated after 20 hours, and was transferred to the general ward on day 2 postoperatively. The mediastinal chest tube was removed on postoperative day 5, the pericardial Hemovac drain was removed on day 10 postoperatively, and the patient was discharged on postoperative day 19 without showing any other complications.\nConsidering R1 resection at the surgical margins, postoperative chemoradiation (chemotherapy, low-dose cisplatin: 7 cycles, radiotherapy, total 6,300 cGy/34F) was applied beginning from day 29 after surgery. Based on chest CT results taken 6 months after surgery, no signs of tumor relapse were observed and the patient did not show any abnormal signs or symptoms ().