Late rupture is of increasing concern after endoluminal repair of abdominal aortic aneurysm. This usually results from detectable failure or migration of the endograft. Surveillance programmes are therefore generally recommended so that problems, particularly endoleak, can be corrected.

ASERNIP-S, the Australian audit of endoluminal repair of abdominal aortic aneurysm, reported at 12 months follow-up, a 3.8% incidence of Type I endoleak (incomplete seal between the ends of the endograft and the native arterial wall) and a 15.2% incidence of Type II endoleak (filling of the residual aneurysm sac from branch arteries). New endoleaks were observed at all intervals of follow-up.

There has been concern about the radiation exposure from frequent CT scans so there has been increased interest in colour-enhanced ultrasound as the first-line method of surveillance, with selective use of CT scanning and angiography. There are concerns using MR with metallic stents. Plain X-rays are the best means to detect wire fracture or separation. Ultrasound can monitor the aortic diameter and detect blood flow in the aneurysm sac, indicative of endoleak, and usually localize its source. Intervention is usually indicated for all Type I endoleaks, and selectively for Type II.

1. Stavropoulos SW, Baum RA. Imaging modalities for the detection and management of endoleaks. Semin Vasc Surg 17:154-60, 2004