The role of ethylene–vinyl alcohol copolymer in association with other embolic agents for the percutaneous and endovascular treatment of type Ia endoleak

Aim: To evaluate safety, technical and clinical success of embolization of type Ia endoleak (T1a EL) using ethylene–vinyl alcohol copolymer as embolic agent alone or in combination with other materials. Materials and methods: Five patients presented T1a EL after endovascular repair of aortic aneurysms (EVAR) with radiological evidence of expanding sac size; in particular, three had contained rupture. In one patient, proximal cuff insertion was previously performed, in three patients proximal cuff was urgently inserted but T1a EL persisted; one patient, previously treated with Ovation Abdominal Stent Graft System, was directly proposed for endovascular treatment. In all cases, endovascular embolization was successfully performed and the transfemoral approach was always chosen; in one case it failed and translumbar approach by direct puncture of the sac was required. Used embolization agents were glue, ethylene–vinyl alcohol copolymer (Onyx) and coils in three cases, n-butyl cyanoacrylate and Onyx in one case, Onyx and coils in the last case. Results: Technical success rate was 100% as well as clinical success. No major or minor complication, including non-target embolization, was registered. Clinical success was 100% until today and the sac diameter remained stable in four patients and decreased in one. Conclusions: Onyx may be considered a suitable embolic agent in the treatment of patients with type Ia endoleaks after EVAR, after failure of conventional treatments such as prolonged balloon inflation of the aortic neck or deployment of large bare stent.