Infected atherosclerotic ulcer of the abdominal aorta as a cause of mycotic aneurysm treated by in-situ prosthetic graft reconstruction: report of a case.

A 68-year-old man with an infrarenal mycotic aneurysm underwent successful in-situ graft reconstruction using a woven Dacron graft. A tissue culture taken from the excised aortic wall revealed Staphylococcus epidermidis, and histological study subsequently showed penetrating atherosclerotic ulcers (PAU) involving all layers of the aortic wall and marked neutrophilic infiltration with abscess formation inside the ulcer. Atherosclerotic aortic lesions such as PAU are considered susceptible to bacterial infection, which may lead to the formation of an aneurysm after destruction of the vessel wall. Hence, elderly hypertensive patients, being at high risk for such aortic pathology, require careful studies performed to assess the aorta. The usefulness of computed tomographic (CT) scans to determine the presence of PAU or surrounding inflammation should be borne in mind even when a small mycotic aneurysm exists.