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 longterm shrinkage of the AAA sac after endovascular repair. Methods: A total of 123 patients with AAA underwent endoluminal treatment w ith 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 wer e 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 embolot herapy. 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 c onsidered a complete collapse of the sac. Results: Successful endoluminal repair was accomplished in 119 of 123 patie nts. The mortality rate was 0.8% (1/123). There was a steady decrease in AA A 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 siz e of 0.5 cm or more, with 28% (11/39) complete collapse. Patients with init ial endoleaks had the same likelihood of regression of sac size (greater th an or equal to 0.5 cm) when compared with the group of patients with no end oleaks at the 24-month evaluation (64% vs 76%, P = .09). Conclusion: Endoluminal AAA repair resulted in a significant reduction in s ac size that continues up to 2 years. Significant shrinkage occurs as early as 6 months after place ment. The initial presence of endoleaks does not p redict the lack of sac regression.