Iliac arterial injuries after endovascular repair of abdominal aortic aneurysms: Correlation with iliac curvature and diameter

PURPOSE: To determine the relationship between iliac arterial tortuosity an d cross-sectional area and the occurrence of iliac arterial injuries follow ing transfemoral delivery of endovascular prostheses for repair of abdomina l aortic aneurysms. MATERIALS AND METHODS: Iliac arterial curvature values and orthogonal cross -sectional areas were determined from helical computed tomographic (CT) dat a acquired in 42 patients prior to transfemoral delivery of aortic stent-gr afts. The curvature and luminal cross-sectional area orthogonal to the medi an centerline were quantified every millimeter along the median centerline of the iliac arteries. An indicator of global iliac tortuosity, the iliac t ortuosity index, was defined as the sum of the curvature values for all poi nts with a curvature of 0.3 cm(-1) or greater, and cross-sectional area (CS A) was indexed for all points as the mean cross-sectional diameter ((D) ove r bar = 2 root [CSA/pi]). Following stent-graft deployment, helical CT data were analyzed for the presence of iliac arterial dissections independently by two reviewers. RESULTS: Eighteen dissections were detected in 16 patients. The iliac tortu osity index was significantly larger in iliac arteries with dissections (35 .5 +/- 20.8 [mean +/- SD]) when compared with both nondissected contralater al iliac arteries in the same patients (26.1 +/- 21.0, P = .001) and iliac arteries in patients without any iliac arterial injury (20 +/- 9, P = .009) . The tortuosity index was higher ipsilateral to the primary component deli very in 10 of 11 iliac dissections that developed along the primary compone nt delivery route. CONCLUSION: A high degree of iliac arterial tortuosity appears to impart gr eater risk for the development of iliac arterial injuries in patients under going transfemoral delivery of endovascular devices.