AEF is a relatively rare condition that is often life-threatening [1-3].There are several etiologies of primary AEF including thoracic aortic aneurysm, foreign body ingestion, esophageal malignancy, and prolonged gastric intubation [6, 7]. There are several etiologies of secondary AEFresulting fromsurgery in the posterior mediastinumsuch as aortic arch replacement, TEVAR to descending aorta, and esophageal surgery [4, 8].The number of secondary AEFis increasing due to increase in the number of TEVAR being performed. Treatment of secondary AEFcan be more challenging than that of primary AEF due to the presence ofadhesion in the pleural space and the poor general status of patients. In the patients in this study who underwent combined repair, reconstruction of the aorta and esophagus could not be completed due to severe adhesions caused by previous TEVAR. There have been few studies comparing the degree of adhesion betweenpost-TEVAR cases and post-graft replacement cases, however,secondary AEF after TEVAR can be more critical than secondary AEF after graft replacement.
The exact mechanism of secondary AEF after TEVAR remains unknown. Eggebrecht et al. reported that the incidence of AEF was 1.9% and occurred 1–16 months following intervention in a series of 268 patients who underwent TEVAR . Some reports suggested that its pathogenesiswas related to inflammation of the aneurysmal wal [9, 10]. They also suggested that the pathogenesis was related to esophageal ischemia secondary to elevated pressure in the posterior mediastinum, inflammation due to the resorbed hematoma, and mechanical compression by a large aneurysm following TEVAR [9, 10]. In post-TEVAR cases, fistulas were reportedly caused by endoleaks into the residual aneurysmal sac, erosion of the stent-graft through the aorta, and ischemic necrosis of the esophageal wall due to compression of its feeding arteries by the stent-graft [4, 5]. In accordance with these reports, severe adhesion between the descending aorta and esophagus might occur more frequently in secondary AEF after TEVAR than after graft replacement. In aortic rupture cases, endovascular stenting does not remove the hematoma or the thrombosis, and thoracic compartment syndrome is likely to occur. Therefore, emergency TEVAR is associated with an increased risk of AEF occurrence [4, 5, 11].In the present study, in three (75%) patientswho had undergoneTEVAR previously,AEF developed after emergency TEVAR.
It has been previously reported that aggressive treatment for patients with AEF was associated with good outcomes [5, 10, 12]and reduced short-term mortality.In the present study, although patients who received open surgical repair were hospitalized for a longer period, they were discharged without complications. However, the patients who underwent TEVAR alone were also discharged without complications. Moreover, they were hospitalized more shortly than open surgical repair cases. The patients who received combined repair were hospitalized for a long period and died subsequently during hospitalization. In secondary AEF after TEVAR cases, palliative treatment using TEVAR without open reconstuction of aorta and esophagus maybe better as an alternative. If the remained esophagus is problematic or bleeding control is necessary, esophageal stent can be introduced.Although TEVAR was proposed as an alternative surgical management strategy for open surgery , late complications of TEVAR are becoming increasingly evident [4, 5]. The treatment strategy for secondary AEF after TEVAR should be carefully designed considering the presence of severe adhesions between the aorta and esophagus. Moreover,the patient’s frailty should be considered in the decision of treatment.Further studies on treatment strategy for secondary AEFincludingsurgical indications and exclusion criteria are warranted.
This study had several limitations. First, a small number of patients was included owing to the rarity of secondary AEF. Therefore, accurate evaluation might be difficult because combined surgery was performed on severely ill patients. Second, it was a retrospective study and the data were obtained from a single institution. Therefore, the study results may not reflect the general features of patients with AEF. Third, endovascular treatment strategy has evolved during the time period of this study.