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.