A comparative study of iliac and abdominal aortic aneurysms

The aim of the paper is to compare the epidemiology, risk factors and manifestations of iliac and abdominal aortic aneurysms.

Two studies were used: 1. 5,470 65-73-year-old men invited for screening for abdominal aortic aneurysms. 2. Review of all 350 patients operated on for central aneurysms in the county of Viborg, Denmark from 1989-1997.

4,176 attended for screening. One hundred and seventy (4.0%) had an abdominal aortic aneurysm. Twenty-one (0.56%) needed operation. The proportion of patients with common iliac aneurysms requiring surgery was 0.17%. The operative incidence of iliac aneurysm was 18.4 per million per year, and 92.4 per million per year were operated on for abdominal aortic aneurysm. The mean serum cholesterol level for isolated iliac aneurysm and combined aneurysms was significantly lower compared to isolated abdominal aortic aneurysm (p<0.05). Urological symptoms were present in 42% of cases with isolated iliac aneurysm, and 25% of combined aneurysms compared to 8% of isolated abdominal aortic aneurysms. Fifty-eight percent of the isolated iliac aneurysms were ruptured, as against 27% of the abdominal aortic aneurysms. The peri- and postoperative mortality was 57% in ruptured isolated iliac aneurysms, 47% in ruptured combined aneurysms, and 31% in ruptured isolated aortic aneurysms.

Iliac aneurysms seem to be more underdiagnosed than abdominal aortic aneurysms, and are often diagnosed because of clinical manifestations, especially urological, or rupture. Iliac aneurysms seem more lethal than those of the abdominal aorta in cases of rupture.