Midterm results of the transarterial use of Onyx in the treatment of persisting type II endoleaks after EVAR

Aim. Type II endoleaks with growing aneurysm sac >5 mm in diameter after EVAR require treatment. Different treatment options have been reported. The aim of this study was to evaluate the use of an ethylene-vinyl alcohol copolymer (Onyx) in an endovascular approach. Methods: Between January 2010 and December 2011, 10 consecutive patients with persistent type II endoleaks leading to aneurysm growth >5 mm were treated in our center by transarterial Onyx embolization by super selective cannulation of the endoleak with microcatheters. Technical success was defined as transarterial Onyx deployment directly into the aneurysm sac. Clinical success was defined as stable or shrinking axial aneurysmal diameter during follow-up using an angiographic computed tomography. Results. Ten patients with 13 persistent type II endoleaks leading to aneurysm sac growth of >5 mm were identified in the time period. Technical success was 92% (12/13 patients). Two patients underwent a staged procedure because several, unconnected type II endoleaks were present. In one patient a cannulation of the inflow vessel responsible for the endoleak was not possible, continued efforts led to a rupture of the hypogastric artery which was treated by covered stent implantation. In one patient an extravasation of onyx out of the aneurysm sac into the inferior vena cava during the embolization process made a transvenous goose snare maneuver necessary to retrieve the dislocated copolymer. No further complications were observed during the mean follow-up of 19.8 months (range, 3-31 months). In all patients with successful embolization the aneurysm sac remained stable or was decreased within the follow-up period. Conclusion. Use of Onyx in the endovascular treatment of type II endoleaks after EVAR is feasible, safe when accurately deployed and efficient. Further studies are necessary to evaluate the value of the different treatment modalities (translumbar vs. transarterial).