Clinical outcomes for endovascular repair of abdominal aortic aneurysm with the Seal stent graft

Abstract

Objective: Since 2007, the availability of the Seal (S & G Biotech Inc, Seong-nam, Gyeonggi-do, Korea) stent graft for endovascular aneurysm repair (EVAR) has improved short-term outcomes in Korea. However, midterm outcome data are lacking. This retrospective study evaluated the midterm outcomes of 126 patients who underwent EVAR using the Seal stent graft between 2007 and 2010.

Methods: Data regarding use of the Seal stent graft for EVAR were collected from 16 Korean centers, and were analyzed retrospectively using Kaplan-Meier and Cox univariate and multivariate analyses.

Results: The mean patient age was 71 ± 8 years (median, 70; range, 49-87 years). Patients who were treated using a bifurcated graft (113; 90%) were generally symptomatic (56; 44%, which included 13 ruptured abdominal aortic aneurysms [10%]) and male (105; 83%). The primary technical success rate was 99%. Four patients (3%) died within 30 days, 5 patients (4%) died after 30 days, and 12 patients (9%) were lost to follow-up. The survival rates were 97% ± 2% (1 month), 97% ± 2% (3 months), 96% ± 2% (6 months), 96% ± 2% (1 year), 94% ± 3% (3 years), and 81% ± 10% (5 years). During a mean follow-up of 55 ± 22 months (median, 40; range, 0.03-91.2 months), 18 reinterventions were performed for 16 patients (13%). The freedom from reintervention rates were 96% ± 2% (1 month), 96% ± 2% (3 months), 94% ± 2% (6 months), 89% ± 3% (1 year), 84% ± 4% (3 years), and 57% ± 17% (5 years). The mean aneurysm diameter significantly decreased from 69.6 to 46.6 mm during the follow-up (P < .0001). A proximal neck of less than 15 mm, different simultaneous endoleaks, and insufficient bilateral coverage of the iliac aneurysm were associated with significantly higher rates of increased or unchanged aneurysm diameters (all P < .0001). Significantly higher rates of clinical failure were observed in patients who were less than 70 years old (P = .04), had a neck length of less than 15 mm (P = .02), and had a neck diameter of greater than 28 mm (P = .02).

Conclusions: Most Seal stent grafts were implanted successfully (even in cases with a physical status of grade IV or higher or a ruptured abdominal aortic aneurysm), had an appropriate reintervention rate, and were stable during the midterm follow-up. However, there was a high rate of type I endoleak, which may be related to the early device model that we used. Therefore, long-term radiologic follow-up is recommended for the early detection of stent graft migration or endoleaks.