Outcome of common iliac arteries after aortoaortic graft placement during elective repair of infrarenal abdominal aortic aneurysms.

Purpose: The purpose of this study was determination of the expansion rates relative to the size of the common iliac artery (CIA) after elective placement of a straight aortic tube graft for an infrarenal abdominal aortic aneurysm (AAA).
Methods: Between January 1993 and December 1997, 74 men (mean age, 69 years) with AAA underwent surgical repair with a straight tube graft. All patients underwent preoperative and postoperative computed tomography (CT) scans. The mean follow-up period was 68.3 months. The preoperative CT scan revealed a dilatation of at least one of the two CIAs in 32 patients (43.2%; group A). Within this group, the CIA was ectatic (12 mm < diameter < 18 mm) in 13 patients (subgroup A1) and aneurysmal (diameter >/=18 mm) in 19 patients (subgroup A2). The diameters of both CIAs were normal (diameter </=12 mm) in the other 42 patients (56.8%; group B).
Results: Two patients (2.7%) in group A2 needed reoperation because of expansion of the diameter of the CIA; the preoperative diameter of the CIA in both patients was 30 mm. The diameters of the CIA aneurysms in the 17 other patients in subgroup A2 were smaller than 30 mm on the preoperative CT scan. After aortic surgery, the sizes of these aneurysms remained stable the first 5 years and reached a diameter of 30 mm on the CT scans obtained 7 to 8 years after surgery. Overall, 10 of the 74 patients (13.5%) had a CIA aneurysm develop that was smaller than 30 mm in diameter (mean diameter, 19.2 mm) 7 to 8 years after aortic surgery. The presence of a celiac aorta dilatation greater than or equal to 25 mm was the only statistically significant factor predictive of postoperative expansion of a CIA dilatation (P =.03).
Conclusion: Straight aortoaortic tube grafts are indicated for CIAs with diameters smaller than 18 mm. Aorta biiliac bifurcated grafts are justified when the CIA diameter is between 18 and 30 mm, when the patient's life expectancy is longer than 8 years, or when the diameter of the celiac aorta is greater than or equal to 25 mm. A CIA aneurysm greater than or equal to 30 mm should be repaired during the same operative session as the AAA with placement of an aorta biiliac bifurcated graft.