Ruptured inflammatory abdominal aortic aneurysm (AAA) is relatively rare and there has been little documentation of the process of rupture. An 83-year-old man presented with abdominal pain, abdominal tenderness and mild elevation of serum inflammatory makers for 1 week. Computed tomography demonstrated an AAA with a periaortic high-density area located just outside the calcified aorta, which was suspected to represent fresh haemorrhage. Emergency surgery revealed an inflammatory AAA with sealed rupture and localized haemorrhage into the thickened retroperitoneal fibrosis.
The thickened aneurysm wall with fibrous tissue is often so rigid at elective surgery that it is difficult to understand how extravasation into the retroperitoneal space can occur. To our knowledge, the present case is a rare example of leakage confined within the thickened retroperitoneal fibrosis and may represent a transitional state in the process of rupture through the inflammatory mantle surrounding the aorta. It also suggests that inflammatory tissue can completely enclose the AAA and prevent major leakage, thus maintaining haemodynamic stability for 1 week ( Figs. 1 and 2 ).
