Surgical Approach to Giant Thymoma: Is the Hemi-Clamshell Incision the Best Option?

We read with interest the article by Gotte and Bilfinger titled “Resection of giant right-sided thymoma using a lateral thoracotomy approach followed by median sternotomy for completion thymectomy”. As the authors have pointed out, the most commonly used approach for thymomas is a median sternotomy, but they decided to perform a lateral thoracotomy because of the size and location of the tumor in the right chest cavity. The mass was successfully resected, and a median sternotomy was performed in a separate setting for completion thymectomy. The second surgical procedure was necessary because the thymus gland could not be resected due to limited exposure of the right lateral thoracotomy [[1]].

A median sternotomy is the most common approach for anterior mediastinal tumors, due to the good exposure of the pericardium, thymus gland and main vessels. However, by a sternotomy, diaphragm, posterior chest wall, and lower lobes are not exposed as well as by a posterolateral thoracotomy, and surgical treatment of mediastinal tumors extensively involving hemithorax is limited.

Various approaches to the chest have been described: posterior, lateral, and anterior approaches are effective surgical options, and the choice of which incision to perform depends on the tumor site and involved structures. Posterior and lateral approaches provide adequate exposure of the chest cavity, but they are not suitable for en bloc resection of a thymoma and the thymus gland, or for resection of other malignancies involving the anterior cervicothoracic junction. For such tumors invading the thoracic inlet, an L-shaped transcervical approach has been described, although the main disadvantage of this technique is the lack of access to the pulmonary vessels which can require a separate posterolateral thoracotomy to perform a major pulmonary resection [[2], [3]].

The hemi-clamshell (or trap-door) incision provides simultaneous effective exposure of the mediastinum, the involved hemithorax and the anterior cervicothoracic junction, and access to the pulmonary hilum is excellent [[4], [5], [6]]. The surgical technique consists of a median partial sternotomy combined with an anterolateral thoracotomy in the fourth intercostal space. The incision can be prolonged to the cervical region to provide an excellent view of the subclavian vessels. When the tumor involves the inferior chest cavity, as in the case presented by Gotte and Bilfinger, the thoracotomy can be performed in the fifth intercostal space to facilitate access to the lower lobe and diaphragm [[7]]. On the other hand, the hemi-clamshell approach does not provide a good exposure of the posterior chest wall, and a posterolateral thoracotomy can be required to facilitate a chest wall resection [[5]].

In the last ten years, 77 tumors of the anterior mediastinum were resected in our department: 52 thymomas, 15 carcinomas of the thymus and 10 germ cell tumors. We performed an hemi-clamshell incision in 14 cases because of the size and location of the tumor. En bloc resection of the mediastinal tumor and invaded structures was successful in all patients, and no additional posterolateral thoracotomy was necessary. We had no complications due to the surgical approach.

As reported, the hemi-clamshell incision does not have a greater morbidity than standard approaches [[5], [7]]. In our experience, for large tumors involving both the anterior mediastinum and one chest cavity, the hemi-clamshell incision has several advantages over traditional approaches: exposure of the mediastinum, chest cavity and anterior cervicothoracic junction is excellent, major pulmonary resection is facilitated, and surgical resection is usually a single-step procedure.

References

• 1 Gotte J M, Bilfinger T V. Resection of giant right-sided thymoma using a lateral thoracotomy approach followed by median sternotomy for completion thymectomy.  Thorac Cardiovasc Surg. 2007;  55 336-338
• 2 Dartevelle P G, Chapelier A R, Macchiarini P. et al . Anterior transcervical-thoracic approach for radical resection of lung tumors invading the thoracic inlet.  J Thorac Cardiovasc Surg. 1993;  105 1025-1034
• 3 Grunenwald D, Spaggiari L. Transmanubrial osteomuscular sparing approach for apical chest tumors.  Ann Thorac Surg. 1997;  63 563-566
• 4 Bains M S, Ginsberg R J. Jones WG 2nd et al . The clamshell incision: an improved approach to bilateral pulmonary and mediastinal tumor.  Ann Thorac Surg. 1994;  58 30-32
• 5 Korst R J, Burt M E. Cervicothoracic tumors: results of resection by the hemiclamshell approach.  J Thorac Cardiovasc Surg. 1998;  115 286-295
• 6 Ohta M, Hirabayasi H, Shiono H. et al . Hemi-clamshell approach for advanced primary lung cancer.  Thorac Cardiovasc Surg. 2004;  52 200-205
• 7 Lardinois D, Sippel M, Gugger M. et al . Morbidity and validity of the hemi-clamshell approach for thoracic surgery.  Eur J Cardiothorac Surg. 1999;  16 194-199