Transsternal Thymectomy Anna Maria Ciccone, Bryan F. Meyers  Operative Techniques in Thoracic and Cardiovascular Surgery  Volume 6, Issue 4, Pages 190-200 (November 2001) DOI: 10.1053/otct.2001.30176 Copyright © 2001 Elsevier Inc. Terms and Conditions

1 (A, B) After induction of general anesthesia, the patient is placed in a supine position with the arms at the sides. A pad can be placed behind the patient's shoulders to extend the neck and improve access to the upper end of the incision. The incision is made from beneath the suprasternal notch to the lowermost point of the xiphisternum and extended to the periosteum of the sternum and linea alba with electrocautery. The sternum is divided at the midline along its length with a sternal saw with a vertical oscillating blade. Operative Techniques in Thoracic and Cardiovascular Surgery 2001 6, 190-200DOI: (10.1053/otct.2001.30176) Copyright © 2001 Elsevier Inc. Terms and Conditions

2 A sternal spreader with broad blades is positioned and opened gradually to avoid fracture of the sternum and upper ribs and neurologic insult. Fatty tissue behind the sternum is cleared laterally with a swab, and the pretracheal fascia is exposed as it extends down from the neck to form the anterior capsule of the thymus. Operative Techniques in Thoracic and Cardiovascular Surgery 2001 6, 190-200DOI: (10.1053/otct.2001.30176) Copyright © 2001 Elsevier Inc. Terms and Conditions

3 After the thin fascia around the perimeter of the thymus is incised, blunt and sharp dissection are used to free the gland from the pericardium and the adjacent mediastinal pleura, exposing and reflecting cephalad the lower poles. At this time, the pleural spaces are usually opened to allow early visualization of the phrenic nerves. If the thymoma abuts the mediastinal pleura, then this pleura should be left attached to the mass and resected with it. Mobilization is continued from caudal to cranial, using the electrocautery with caution to avoid unintentional injury of the small arterial branches from the internal mammary artery. These branches should be identified and divided between ligatures on each side. Additional blood supply is encountered arising from the inferior thyroid artery at the upper extent of the dissection. Operative Techniques in Thoracic and Cardiovascular Surgery 2001 6, 190-200DOI: (10.1053/otct.2001.30176) Copyright © 2001 Elsevier Inc. Terms and Conditions

4 As the dissection plane approaches the innominate vein, one to three thymic veins are encountered. These veins enter the innominate vein inferiorly and anteriorly and should be ligated and transected. With the thymus reflected upward, the entire anterior surface of the pericardium is exposed. When the tumor abuts the pericardium, the surgeon should not hesitate to resect with liberal margins any portion of the pericardium attached to the tumor. Operative Techniques in Thoracic and Cardiovascular Surgery 2001 6, 190-200DOI: (10.1053/otct.2001.30176) Copyright © 2001 Elsevier Inc. Terms and Conditions

5 Retraction of the upper end of the wound allows identification of the two upper poles of the thymus passing upward into the neck. Gentle traction of the body of the thymus and blunt dissection of the cervical extension of each lobe will deliver these into the wound. After the thyrothymic ligament and the adjacent veins are divided, the upper poles of the thymus are freed. Operative Techniques in Thoracic and Cardiovascular Surgery 2001 6, 190-200DOI: (10.1053/otct.2001.30176) Copyright © 2001 Elsevier Inc. Terms and Conditions

6 It is important to remove all of the adipose tissue to ensure complete removal of any collections of identifiable macroscopic and microscopic thymic tissue that may be found as additional mediastinal lobes and islets of tissue outside the thymic capsule extending from the neck to the diaphragm. Operative Techniques in Thoracic and Cardiovascular Surgery 2001 6, 190-200DOI: (10.1053/otct.2001.30176) Copyright © 2001 Elsevier Inc. Terms and Conditions

7 To achieve an “extended” thymectomy, careful exploration of both pleural spaces is necessary, searching for supernumerary lobes and discontinuous nodules and excision of the anterior mediastinal fat from the pericardiophrenic angles inferiorly to the neck superiorly and laterally from phrenic nerve to phrenic nerve. (Reprinted with permission.17) Operative Techniques in Thoracic and Cardiovascular Surgery 2001 6, 190-200DOI: (10.1053/otct.2001.30176) Copyright © 2001 Elsevier Inc. Terms and Conditions

8 If an invasive tumor is found, then en bloc removal of affected structures is performed along with the total thymectomy. These resectable structures include pericardium, pleura, lung, phrenic nerve, innominate vein, vena cava, and the chest wall. Small pericardial defects do not necessitate specific reconstruction, though larger and lateral defects create a risk for cardiac herniation and should be repaired. To achieve a complete resection, all resectable mediastinal structures invaded by the mass should be resected. (A) The reconstruction after resection of pericardium and innominate vein. The reconstruction of the pericardium was achieved with Marlex mesh and and the vein was replaced with bovine pericardium. (B) The result after resection of a stage III thymoma invading innominate vein and superior vena cava and reconstruction with a ribbed polytetraflouroethylene prosthetic graft. If a single phrenic nerve is involved, then resection of the tumor and the attached nerve should be carried out according to the preoperative evaluation of the patient's respiratory status and the functional state of both nerves before surgery. If both phrenic nerves are involved and functioning preoperatively, neither should be resected and the area should be debulked only. Clips should mark those areas of residual disease to facilitate postoperative radiotherapy. Operative Techniques in Thoracic and Cardiovascular Surgery 2001 6, 190-200DOI: (10.1053/otct.2001.30176) Copyright © 2001 Elsevier Inc. Terms and Conditions

9 After a simple thymectomy that did not include pleural entry, a suction drainage or chest tube is placed in the anterior mediastinum and brought out through a stab wound near the lower end of the incision. In the more typical case of bilateral opened pleural spaces, however, one or two pleural tubes are required. Once the resection and reconstruction have been completed, the sternum is approximated with four to eight stainless steel wires passed around the sternum through the intercostal spaces. Operative Techniques in Thoracic and Cardiovascular Surgery 2001 6, 190-200DOI: (10.1053/otct.2001.30176) Copyright © 2001 Elsevier Inc. Terms and Conditions