Endograft migration one to four years after endovascular abdominal aortic aneurysm repair with the AneuRx device: a cautionary note.

BACKGROUND

Positional stability of the endograft is essential for long-term durability after endovascular abdominal aortic aneurysm repair (EAR). However, the cumulative risk of delayed endograft migration has been sparsely reported.

METHOD

A total of 91 patients studied underwent EAR with the AneuRx endograft with a minimum 1 year from implantation. Data from a prospective database were assessed for proximal endograft migration, defined as > or = 5 mm change from the initial endograft position. Multiple anatomic characteristics were also examined. Sixty-nine patients were alive, with complete follow-up at 1 year, with a mean time from implantation of 33.2 +/- 1.1 months. Data are mean +/- SEM.

RESULTS

Endograft migration occurred in 15 patients, giving a cumulative event rate of 7.2% (5/69) at 1 year, 20.4% (10/49) at 2 years, 42.1% (8/19) at 3 years, and 66.7% (2/3) at 4 years post-EAR (P =.01). Although the initial aortic neck diameter did not differ between the groups (21.5 +/- 0.6 mm vs 21.8 +/- 0.3 mm, P =.61), significant (P <.05), late aortic neck enlargement was seen in patients with migration (25.0 +/- 1.6 mm, 26.2 +/- 1.2 mm, and 27.0 +/- 1.0 mm at 1,2, and 3 years, respectively) but not in nonmigrators. Regression analysis demonstrated a statistically significant (P <.05) correlation between endograft oversizing and late aortic neck dilation. Overall migration risk was 29.2% in patients oversized >20% and 18.6% in patients oversized < or = 20%. Aortic neck angulation (23.4 +/- 6.6 degrees vs 23.5 +/- 3.3 degrees, P =.99), aortic neck length (25.9 +/- 2.5 mm vs 27.0 +/- 1.6 mm, P =.74), initial endograft/aortic neck overlap (18.6 +/- 2.6 mm vs 19.4 +/- 1.4 mm, P =.80) and size of abdominal aortic aneurysm (55.5 +/- 1.5 mm vs 54.9 +/- 1.4 mm, P =.84) were similar between migrators and nonmigrators, respectively. Secondary endovascular treatment with aortic cuffs was required in five patients with device migration.

CONCLUSIONS

Device migration after EAR with the AneuRx endograft occurred with significant frequency, the incidence of which increased with the length of follow-up. Late aortic neck dilation was significantly associated with migration. Oversizing of the endograft of >20% may accelerate this late aortic neck dilation. However, the etiologies of endograft migration were likely multifactorial, as the majority (8/15) of patients experiencing migration were oversized <20%. Although endovascular repair of these migrations is usually possible, the long-term durability of these secondary procedures is unknown. Careful surveillance for this endograft failure mode must be an essential component of post-EAR follow-up.