0230: Ultrasound Detection of Intermittent and Positional Dependent Endoleaks; Evidence for a Novel Mehanism of AAA Sac Growth After Endovascular Repair

IntroductionUltrasound is a reliable tool for real-time identification of endoleaks after endovascular repair of abdominal aortic aneurysms (AAA). We have identified a unique subset of patients in whom the endoleak has been shown to be intermittent, with strong evidence of variations in flow with patient positioning.MethodsAll patients presenting with prior endograft repair of AAA were imaged with Philips HDI 5000 and IU22 ultrasound systems using a standard protocol including spectral and colour Doppler analysis. When there were signs of AAA sac growth or instability, patient positioning was varied during the examination including left and right decubitus views to search for evidence of intermittent endoleak. Correlation was made to angiography and CT imaging.ResultsIntermittent endoleaks were confirmed in 13 patients, all of whom had sac enlargement. There was evidence of positional dependence in 11 of the 13 cases. This represents an incidence of less than 1% in a series of more than 1200 endovascular repairs, but 48% (13 of 27) of patients with unstable AAA sac or endotension. These endoleaks were not seen on CT scans in 80% of studies, and 11 of 13 were not seen on supine angiography.ConclusionEndoleaks may be intermittent and position-dependent. Duplex ultrasound is an essential component in diagnosis, enhanced by ultrasound's ability to capture dynamic, real time images. Special posturing should be used in patients with suspicious signs. IntroductionUltrasound is a reliable tool for real-time identification of endoleaks after endovascular repair of abdominal aortic aneurysms (AAA). We have identified a unique subset of patients in whom the endoleak has been shown to be intermittent, with strong evidence of variations in flow with patient positioning.