Does Endograft Support Alter the Rate of Aneurysm Sac Shrinkage after Endovascular Repair?

Abstract

Purpose:

To test the hypothesis that stent-graft support influences sac shrinkage independent of endoleak rates after endovascular repair of abdominal aortic aneurysms (AAA).

Methods:

Ninety AAA patients underwent treatment with bifurcated endoluminal devices at our institution between October 1996 and February 1999. Fifty-two patients were treated using a nonsupported (NS) Ancure endograft and 38 using a fully supported (FS) Excluder endograft. Computed tomographic (CT) scans were obtained during the first postoperative month and at 6, 12, and 24-month intervals. Aneurysm diameter was measured as the minor axis of the largest AAA axial slice on the CT scan. Six, 12, and 24-month sac sizes were compared to the first postoperative evaluation.

Results:

Successful endoluminal graft placement was accomplished in all patients. The two groups were matched for age, anatomical criteria, and comorbidities except for baseline AAA size: the mean diameter was 5.4 cm in the NS group and 5.0 cm for the FS group (p<0.01). Endoleak rates were 25% (13/52) in the NS group and 18% (7/38) in the FS group (p<0.05) at 1 month. All endoleaks that did not resolve spontaneously at 6 months were treated. Initial endoleak status did not affect the sac shrinkage rates at the 12 and 24-month evaluations. At 2 years, the NS group had greater shrinkage of the sac (1.2 cm) versus the FS cohort (0.3 cm, p<0.05). In addition, more patients in the NS group had sac shrinkage >5 mm (83% versus 18%, p<0.05).

Conclusions:

Despite a higher endoleak rate, the nonsupported Dacron Ancure endografts were associated with greater sac shrinkage at up to 24 months following implantation.