Lateral movement of endografts within the aneurysm sac is an indicator of stent-graft instability.

PURPOSE To determine if lateral movement of an aortic endograft 1 year following endovascular abdominal aortic aneurysm (AAA) repair is an indicator of endograft instability and can serve as a predictor of late adverse events. METHODS The records of 60 high-risk AAA patients (52 men, 8 women; mean age 74 years) who were treated with infrarenal (n = 38) or suprarenal (n = 22) endografts and had serial computed tomograms (CT) over > or =12 months were analyzed. Postimplantation and 1-year CT scans were compared, and changes in endograft position within the aneurysm sac [lateral movement (LM) versus no lateral movement (NM)] were measured using a vertebral body reference point. Longitudinal endograft movement was measured with respect to the superior mesenteric artery along the aortic centerline axis. Long-term adverse event rates (endoleaks, secondary procedures, conversion, rupture, and death) were assessed. RESULTS One year after endograft implantation, LM > or =5 mm was present in 16 (27%) patients; 44 (73%) endografts demonstrated no lateral movement. LM patients had larger aneurysms (6.5+/-1.5 versus 5.6+/-0.9 cm, p = 0.02) and a longer endograft-to-hypogastric artery length (p = 0.01) than NM patients. There were no significant differences between patients treated with infrarenal and suprarenal endografts. At 1 year, longitudinal migration > or =10 mm occurred in 5 (31%) of the LM patients versus 2 (5%) in the NM cohort (p<0.0001). There were no significant differences in adverse event rates between LM and NM at 1 year. However, during long-term follow-up (mean 54+/-26 months, range 12-102), 8 (50%) LM patients developed a type I endoleak versus 8 (18%) NM patients (p = 0.02), and 12 (75%) LM patients required a secondary procedure versus 9 (20%) NM patients (p = 0.0002). One (6%) LM patient experienced aneurysm rupture and 2 (13%) other LM patients underwent conversion to open repair. CONCLUSION Lateral endograft movement within the aneurysm sac at 1 year is associated with increased risk of late adverse events and was at least as good a predictor of these complications as was longitudinal migration.