Local tumor relapse after definitive chemoradiotherapy occurs in up to 35% of non-small cell lung cancer patients and remains the dominant cause of death after initial therapy [4]. Although there is no clear consensus on the effective local treatment modality, previous studies have reported the median progression-free survival (PFS) and overall survival (OS) after salvage surgery to be 12–43.6 months and 22–46 months, respectively [2, 5,6,7]. The studies also reported that salvage lung resection may be a means of achieving local control and improving survival. However, salvage surgery is generally considered as technically more difficult with potentially higher morbidity than alternative therapies. Therefore, careful patient selection and surgical expertise are both extremely important [8].
Some important points with respect to patient selection for salvage surgery are as follows: (1) adequate pulmonary reserve and good performance status, (2) possibility of complete resection, and (3) controlled lymphatic and distant metastases. In the present case, the patient was able to withstand surgery, and lymph node and distant metastases were controlled. Despite aortic invasion, the tumor was considered to be resectable after careful assessment by cardiovascular surgeons. For lung cancers with aortic invasion, complete resection and no mediastinal lymph node metastases have been identified as predictors of improved survival [9]. Induction chemoradiotherapy has been found to improve resectability and survival [10]. In contrast, only one case of unsuccessful salvage surgery combined with descending aorta resection has been reported [5], and no clear evidence is available supporting the suitability of this operation. However, in our case, controlling the tumor progression (the re-enlargement of the primary tumor) using modalities other than surgery would be difficult. Therefore, we presumed that the prognosis could be improved by complete resection combined with aortic resection.
In cases of combined aortic resection, the surgical strategy varies depending on whether the invaded part is the proximal or distal to the left subclavian artery. If the infiltrated part is distal to the subclavian artery, it can be resected by replacing the distal aortic arch or descending aorta. Conversely, it is necessary to replace the aortic arch if the infiltrated part is proximal to the subclavian artery. Unlike replacing the aortic arch, replacing the distal aortic arch or descending aorta maintains the blood flow to the upper body; hence, only the blood flow to the lower body required external management through partial extracorporeal circulation such as the femoral artery–femoral vein bypass (F-F bypass). Therefore, there is no need for cardiac arrest and extracorporeal circulation of the brain. Extracorporeal circulation time is short, and it can be performed relatively safely without complications such as cerebral infarction. In the present case, the aortic infiltration site was considered to be in the distal to the left subclavian artery. This was the primary reason for performing salvage surgery. In fact, the extracorporeal circulation time was approximately 30 min and complications associated with extracorporeal circulation were not observed.
In this case, we did not perform preoperative thoracic endovascular aortic repair (TEVAR) because the infiltrated part was located close to the left subclavian artery (as seen in a preoperative image), resulting in an insufficient landing zone. However, TEVAR followed by surgery is a less invasive and useful alternative option [11]. Particularly, in cases in which the infiltrated part involves the aorta proximal to the left subclavian artery, aortic arch replacement should be avoided by performing fenestration stent placement [12] or by debranching followed by TEVAR [13]; this is because aortic arch replacement is highly invasive.
No clear consensus exists regarding salvage surgery combined with aortic resection for primary lung cancer. However, we believe that this surgery may improve the survival of carefully selected patients.
