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 and cross-sectional area and the occurrence of iliac arterial injuries following transfemoral delivery of endovascular prostheses for repair of abdominal aortic aneurysms. MATERIALS AND METHODS: Iliac arterial curvature values and orthogonal cross-sectional areas were determined from helical computed tomographic (CT) data acquired in 42 patients prior to transfemoral delivery of aortic stent-grafts. The curvature and luminal cross-sectional area orthogonal to the median centerline were quantified every millimeter along the median centerline of the iliac arteries. An indicator of global iliac tortuosity, the iliac tortuosity index, was defined as the sum of the curvature values for all points with a curvature of 0.3 cm(-1) or greater, and cross-sectional area (CSA) was indexed for all points as the mean cross-sectional diameter ((D) over 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 tortuosity index was significantly larger in iliac arteries with dissections (35.5 +/- 20.8 [mean +/- SD]) when compared with both nondissected contralateral 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 delivery in 10 of 11 iliac dissections that developed along the primary component delivery route. CONCLUSION: A high degree of iliac arterial tortuosity appears to impart greater risk for the development of iliac arterial injuries in patients undergoing transfemoral delivery of endovascular devices.