COMMON ILIAC ARTERY ANEURYSMS IN PATIENTS WITH ABDOMINAL AORTIC-ANEURYSMS

Objectives: To determine the incidence of common iliac artery (CIA) an eurysms in patients with abdominal aortic aneurysms (AAA) and to evalu ate the relationship between AAA and CIA diameter. Methods: Spiral CT angiography was used to measure the maximum diameters of the abdominal aorta and the common iliac arteries of 215 patients with AAA. Results : The medium CIA diameter was 1.7 cm - significantly greater than the published mean of 2.25 (2 S.D. = 0.85-1.65) cm of an age-matched, non- vascular population. Thirty-four patients (16%) had unilateral and 26 patients (12%) bilateral CIA aneurysms greater than or equal to 2.4 cm diameter. Eight-six vessels (20%) were affected. Right CIA diameters were wider than left CIA diameters (p<0.0001, Wilcoxon marched-pairs s igned rank test). The correlation between AAA size and CIA diameter wa s weak. Conclusions: The AAA population has abnormally dilated common iliac arteries. In this population, common iliac artery aneurysms shou ld be defined as those greater that 2.4 cm diameter. 20% of CIAs in pa tients with AAA are aneurysmal according to this definition.