Matrix² coils in embolization of intracranial aneurysms: 1-year outcome and comparison with bare platinum coil group...

The endosaccular occlusion by using BPC has been useful in the treatment of intracranial aneurysms, but its limited durability remains a deep-seated drawback. The Matrix² coil, one of the bioactive-coated coils, had been developed to improve this limited durability. To evaluate durability of Matrix² coils after embolization of intracranial aneurysms, we retrospectively compared 1-year outcomes with that of BPC groups.

A group of 121 aneurysms in 114 patients were embolized by using Matrix² coils between April 2006 and September 2008. The BPC group consisted of 151 aneurysms in 137 patients embolized by using BPCs alone between October 2007 and October 2008. The initial outcomes including packing densities, occlusion grades, and periprocedural complications, and the 1-year outcomes on MR angiography were retrospectively compared between the 2 groups.

The Matrix² coil group and BPC group with similar baseline demographic characteristics revealed comparable initial outcomes. The rates of overall recurrence, major recanalization, and retreatment were 17.4%, 14.0%, and 10.7% versus 7.3%, 5.3%, and 4.6%, respectively (P = .066). However, the rates of subgroups with aneurysm volumes between 50 and 200 mm³ were 23.7%, 13.1%, and 10.5% versus 2.2%, 0%, and 0% (P = .022), respectively. The rates of subgroups with packing attenuation <30% were 38.3%, 31.9%, and 23.4% versus 13.3%, 11.7%, and 10% (P = .025), respectively. There were no differences in packing attenuation (P = .152), initial occlusion grade (P = .098), and 1-year outcomes (P = .209) according to the length of Matrix² coils used.

Overall, initial and 1-year outcomes of the Matrix² coil group were comparable to those of the BPC group. However, in certain subgroups of aneurysm volume and packing attenuation, the 1-year durability of Matrix² coils was inferior to that of the BPC group.