A 74-year-old man had an inflammatory pseudoaneurysm of the ascending aorta. He was admitted to a local hospital because of loss of appetite. Following intravenous hyperalimentation, he was placed under ventilatory support because of acute respiratory failure. Since his high fever and respiratory failure continued, he was transferred to our hospital. Computed tomography revealed a sealed rupture of an aneurysm in the ascending aorta. During the operation, we identified the ascending aortic aneurysm but it was very tightly attached to the surrounding wall in the perianeurysmal space. To avoid excessive hemorrhage, we closed the communication between the aneurysm and the aorta with a Dacron graft patch under deep hypothermia with circulatory arrest. He was discharged 42 days after operation without any complications. A pathological evaluation of the aneurysmal wall revealed an inflammatory pseudoaneurysm with a thick and inflammatory infiltration in the adventitia.

Among 232 patients undergoing repair for abdominal aortic aneurysms (AAA) during a 10-year period, 5 (2.2%) patients had evidence of inflammatory abdominal aortic aneurysms (IAAA). We examined their clinical course, laboratory, operative and histopathological findings, and considered possible correlations between their diagnosis and surgical treatment. Among these cases of IAAA, 2 patients complained of severe abdominal or back pain. The differential diagnosis from rupture of AAA was difficult in these cases. They also showed inflammatory signs in laboratory, operative and histopathological findings. Ultrasonography, computed tomography and magnetic resonance imaging appear to offer reliable means for diagnosing IAAA; In particular we could recognize the“Inflammatory mantle”in 3 cases, which indicated IAAA. In the surgical treatment, the presence of IAAA necessitates certain modifications in the surgical approach, in order to avoid injuring the retroperitoneal and abdominal structures. We could observe post-operative change in the thickness of the aortic wall, which decreases with time without anti-inflammatory agents.