Australia & New Zealand Society of Vascular Surgeons

Introduction CT scan is widely used for follow-up of patients after endovascular repair of AAA, however, it is a relatively expensive investigation that involves administration of IV contrast and exposure to irradiation. Aim Our aim was to determine whether US could replace CT scan for follow-up after EVR of AAAs. Materials and Methods 100 patients who had EVR of AAAs between 1997 and 2002 were prospectively followed-up using US and CT scan at 1,6 and 12 months; then annually thereafter. CT scan was assumed to be the gold standard and US was compared to this. The parameters evaluated were the maximum aneurysm body and neck diameters and the presence or absence of endoleaks. Bland-Altmann plots were used to determine the degree of correlation between US and CT, and 4mm was considered the maximum acceptable difference between the two investigations. Results 95% tolerance intervals for US vs CT were -5.06 to 5.59mm for maximum aneurysm body diameters and -6.62 to 3.15 mm for maximum neck diameters. Ultrasound also failed to detect 2/12 endoleaks. Sensitivity and specificity for US detection of endoleaks were 83.3% and 97.4% respectively. Conclusion US was not able to replace CT scan as the investigation of choice for follow-up of patients after EVR of AAAs.