Anastomotic pseudoaneurysm occurred at long time after surgery for atherosclerotic thoracic aortic aneurysm.

We encountered two cases of ruptured anastomotic pseudoaneurysms 47 and 77 months after surgery for atherosclerotic thoracic aortic aneurysms. Autopsy was performed in one case and emergency re-operation was performed in the other case. We gained some interesting findings in the autopsy and the re-operation. The anastomotic sites were sustained by sutures only, and there was no evidence of tissue supplementation at the anastomotic sites in macroscopic observation. Microscopic findings demonstrated endothelium healing on the internal side of the prosthesis near the anastomotic site. There was no tissue connection between the prostheses and the native aortic walls, although over four or six years had passed after the previous anastomoses. Anastomotic pseudoaneurysms may occur even in a long time after surgery. Careful operative procedures and long-term computed tomography or magnetic resonance imaging follow-up are crucial.