Figure 4 : A : The left lobe of the thymus has been removed, exposing the innominate vein, the innominate artery, the left carotid artery and the proximal aortic arch covered by the pericardial investment. B : A full thymectomy is subsequently performed by removing the right lobe and is a key step as it increases the antero-superior mediastinal space. A limited superior pericardiotomy is performed to expose the junction of the innominate artery and the aortic arch. It is critical to not circumferentially dissect the innominate artery.
Typically, three sets of anchoring suture are required. The first set is placed at the junction middle and proximal thirds of the innominate artery, the second set is placed at the base of the innominate artery near the aortic arch and the third set is placed 0.5 to 1 cm below this on the anterior surface of the proximal aortic arch. At times, additional sutures may have to be placed distally and proximally to aforementioned sutures to optimize the result. This can be guided by pulling on the anterior surface of the innominate artery and the arch with real time flexible bronchoscopic exam to assess sites for suture placement (Figure 5 ).