Two autopsy cases of rupture of the aorta by fistula formation after thoracic endovascular aortic repair and open stent-grafting on aortic arch aneurysm.

The mortality rate of aortic aneurysm/dissection is low in Japan. Two surgical procedures, the thoracic endovascular aortic repair (TEVAR) and the open stent-grafting have contributed much in survival of such aneurysmal patients. We encountered with two autopsy cases of death by aortic rupture with fistula formation after these procedures. Case 1 is an 85-year-old male who had the history of TEVAR for thoracic aorta aneurysm one and a half year before his death. His endovascular stent-graft was composed of a steel endoskeleton consisting of six Z-shape elements while at autopsy, one of the elements locating at the distal part was found inserted deep into the wall of descending aorta, causing aorto-esophageal fistula. Case 2 is an 88-year-old male who had the history of open stent-grafting for aortic aneurysm eight years ago. At autopsy, the stent-graft was found detached from aorta at its lesser curvature, causing gap formation between the aorta and the stent. Six Z-shaped stent elements, the parts of stent-graft, were found separated from descending aorta and located in the aneurism. Furthermore, three of the separated elements were found inserted deep in the aortic wall, causing aorto-pulmonary fistula. Since aorto-esophageal fistula formation after surgery for aortic aneurysm is very rare in TEVAR and there are no reported cases of death by aorto-pulmonary fistula in the open stent-grafting, these cases are reported here.