Purpose: To report the incidence of delayed com plications following endova
scular abdominal aortic aneurysm (AAA) repair and the relationship of these
sequelae to morphological changes in the sac and endograft.
Methods:Twenty-six AAA patients treated with Vanguard endografts had comple
ted greater than or equal to 1-year follow-up. Postoperative angiograms and
spiral computed tomographic (CT) scans with 3-dimensional reconstruction w
ere compared to the 1-year images to determine morphological changes in the
aneurysm sac a nd the endograft. These changes were then related to compli
cations occurring between 1 and 12 months postoperatively in the study grou
Results: Comparison of angiograms uncovered endograft buckling in 18 (69%)
patients and acutely angled or kinked endografts in 10 (38%). Measurements
from the CT scans found that undistorted endografts had a mean change in sa
c length of +6.6 mm. Mean sac length change in buckled endografts was -3.1
mm, while kinked endografts displayed a mean change of -6.2 mm (p < 0.002,
Student's t-test). Five (19%) patients, all with distorted endografts, demo
nstrated late (1 to 12 months) complications (4 endoleaks and 1 graft limb
thrombosis) owing to component separation, distal stent migration, and acut
e angulation. No movement in the proximal stent was observed. Elongation of
the endograft (flow line measurement) was observed in one tube graft only.
Conclusions: In this study, longitudinal shrinkage of the sac following end
ovascular aortic aneurysm repair led to buckling or kinking of the endograf
t within 1 year in 69% of patients. This appears to be an important source
of delayed complications.