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


CONCLUSIONS
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.
Department of Surgery, Division of Vascular Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA.
Benjamin Y
BY
Rafii
Oscar J
OJ
Abilez
Peyman
P
Benharash
Christopher K
CK
Zarins
D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography / Q000379:methods; D001363:Awards and Prizes; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D019544:Equipment Failure Analysis; D005260:Female; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D015203:Reproducibility of Results; D015607:Stents; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure