AORTA – Abdominal aortic aneurysm (AAA)

This specimen shows the abdominal aorta from just above the coeliac axis to just below the origin of the common iliac arteries. The lower part of the aorta is expanded to form an aneurysm which is completely filled by thrombus. The thrombus extends down into the common iliac arteries. The aorta shows a number of atheromatous plaques as well. It is believed that weakening of the aortic wall by atheroma contributes to aneurysm formation.
This man was admitted to hospital with paraplegia following a motor vehicle accident. The accident does not appear to have been severe. He had a past history of myocardial infarction. Examination showed femoral pulses on both sides, although both lower limbs were cold and blue, and no popliteal pulse could be felt. Death occurred the following day. At autopsy, the lesion displayed here was found. There was no spinal injury, but there was infarction of the cauda equina. This presumably accounted for the clinical picture, and was secondary to the presence of the aneurysm, rather than to the accident described. Death was ascribed to myocardial infarction as a recent infarct (some 24 hours old) was demonstrated.