Endovascular management of pararenal aortic aneurysms with multiple overlapping uncovered stents.
This study aims at evaluating the safety and efficacy of a porous stent system consisting of multiple overlapping uncovered stents in the treatment of complex aortic aneurysms with vital branches. Data of all patients with aortic aneurysms treated in our center with multiple overlapping uncovered stents between February 2010 and December 2011 were retrospectively reviewed. Preoperative characteristics, intraoperative details, and follow-up outcomes were documented. Technical success was defined as successful deployment of the stents to target locations without procedure-related complications. Clinical success was characterized by complete shrinkage or stabilization of the aneurysm, preservation of vital branches, and absence of major complications. Patients were grouped, according to rapidity of aneurysm thrombosis, into fast-thrombosis group (complete thrombosis of aneurysmal sac was achieved in ≤6 months) and a delayed-thrombosis group (>6 months required for complete thrombosis). Possible factors affecting the speed of thrombosis were analyzed statistically with the Fisher exact test and the t-test. This porous stent system was used to treat 34 patients (23 men, 11 women; mean age, 65.7 years). Technical success was achieved in all patients (100%). Regular follow-up over 6 months was achieved in 29 patients (mean length of follow-up, 11.4 months). Complete thrombosis of the aneurysm sac within 12 months was observed in 24 patients (83%). Aneurysm shrinkage was documented in seven patients (24%) and stabilization in 21 (72%). All branch arteries covered by bare stents stayed patent during follow-up. The overall clinical success rate reached 97% in the follow-up group. Risk factors for delayed thrombosis included fewer stents implanted (P = .013), longer sac entrance (P = .043), and use of antiplatelet medication (P = .040). An alternative method of management of complicated aortic aneurysm appears to be feasible using overlapping bare stents, which may prevent aneurysm growth while preserving vital branches. The short-term outcome of our study seems encouraging but is not sufficient to draw a robust conclusion. Further hemodynamic and clinical studies are warranted to evaluate long-term efficacy.