Fate of endoleaks detected by CT angiography and missed by color duplex ultrasound in endovascular grafts for abdominal aortic aneurysms

Purpose: To analyze the clinical implications of endoleaks documented by computed tomographic angiography (CTA) and missed by color duplex ultrasound (CDU). Methods: During a recent 5-year period, 232 patients underwent endovascular aortic reconstruction (EVAR) and were followed according to a protocol that included CTA and CDU at 1 month and every 6 months thereafter. CTA was the gold standard for determining the presence of endoleaks. The size of the AAA sac at the latest postoperative follow-up was compared to the preoperative size and correlated to the type of endoleak and clinical outcome. This study analyzed only patients with endoleak documented by CTA and CDU and specifically analyzed the outcome of patients with false negative CDU studies for endoleaks. Results: Thirty-nine endoleaks were documented in 35 (15%) of 232 patients using CTA. Four patients had both early and late endoleaks. The mean follow-up was 25 months (range 1-64). CDU was more helpful in detecting type I endoleaks than type 11 endoleaks (89% versus 58%, p<0.05). There were 18 (46%) type I endoleaks (12 early, 6 late) detected by CTA; 16 (89%) of these were detected by CDU (2 late endoleaks missed). Nineteen (49%) type 11 endoleaks (16 early, 3 late) were diagnosed using CTA, 11 (58%) of which were detected by CDU (6 early and 2 late missed). Of the 2 (5%) early type IV endoleaks found on CTA, 1 (50%) was missed by CDU. Overall, CDU failed to identify endoleak in 11 (28%) of 39 endoleaks [2 late type I, 8 type II (6 early, 2 late), and 1 early type IV]. Consequences to treatment occurred in 2 (20%): 1 type I endoleak required treatment and 1 type II endoleak would have missed treatment. Conclusion: CDU has a lower sensitivity in detecting endoleak, particularly type 11; therefore, EVAR surveillance should not be based solely on CDU. Although a significant number of type 11 endoleaks resolved spontaneously, intervention can be offered for type 11 endoleaks if associated with an increasing sac size.