Infrarenal aortic dilatation less than 4 cm is not unusual in patients with aortoiliac occlusive disease.

BACKGROUND

The relationship between atherosclerosis and abdominal aortic aneurysm is now controversial. To better define the contribution of atherosclerosis to the development of aneurysm of the infrarenal aorta, we determined the incidence of aortic dilatation in patients undergoing arterial reconstruction for an atherosclerotic aortoiliac occlusive disease (AIOD). The role of aortic wall calcification and intraluminal thrombus was also determined.

SETTING

patients treated in a university hospital.

SUBJECTS

40 patients who underwent bifurcated graft bypass operation for AIOD without an abdominal aortic aneurysm =or>4 cm in size.

MEASURES

Diameter, luminal calcification and intraluminal thrombus of the infrarenal aorta were evaluated using preoperative contrast enhancement computed tomography.

RESULTS

Sixteen patients (40%) had an infrarenal aorta larger than the aorta at the level of the left renal vein. Of these, 5 patients (12.5%) had a 50% enlargement or more. Infrarenal aortic diameter correlated negatively with the extent of calcification of the infrarenal aorta and positively with the amount of intraluminal thrombus.

CONCLUSIONS

Infrarenal aortic dilatation less than 4 cm in size is not unusual in patients with AIOD, suggesting a possible relationship between aortic atherosclerosis and dilatation. An aorta with atherosclerotic plaque containing abundant thrombus and few calcifications may develop enlargement.