Long-term fate of the aneurysmal sac after endoluminal exclusion of abdominal aortic aneurysms

Purpose: Shrinkage of an abdominal aortic aneurysm (AAA) is the hallmark of successful endoluminal treatment. Our goal was to prospectively assess the midterm to long-term shrinkage of the AAA sac after endovascular repair. Methods: A total of 123 patients with AAA underwent endoluminal treatment with the Ancure device at our institution between February 1996 and February 2000. At least a 1-year follow-up was available for 70 of the 123 patients. AAA sac size, presence of endoleaks, calcifications, and outcome data were collected on these patients at 6, 12, 24, and 36 months after repair and compared with the preoperative AAA size and characteristics. All endoleaks found at the 6-month follow-up visit were treated aggressively with embolotherapy. An AAA sac regression of 0.5 cm or more was considered the minimum measurable decrease. Regression of the sac diameter to 3.5 cm or less was considered a complete collapse of the sac. Results: Successful endoluminal repair was accomplished in 119 of 123 patients. The mortality rate was 0.8% (1/123). There was a steady decrease in AAA sac size from baseline (5.56 ± 0.1 cm), to 6 months (5.0 ± 0.14 cm, P = .0006), to 12 months (4.65 ± 0.13 cm, P = .04), and to 24 months (4.26 ± 0.16 cm, P = .03). At 24 months, 74% (29/39) had a decrease in sac size of 0.5 cm or more, with 28% (11/39) complete collapse. Patients with initial endoleaks had the same likelihood of regression of sac size (≥ 0.5 cm) when compared with the group of patients with no endoleaks at the 24-month evaluation (64% vs 76%, P = .09). Conclusion: Endoluminal AAA repair resulted in a significant reduction in sac size that continues up to 2 years. Significant shrinkage occurs as early as 6 months after placement. The initial presence of endoleaks does not predict the lack of sac regression.