Final results of the multicenter, prospective Axium MicroFX for Endovascular Repair of IntraCranial Aneurysm Study (AMERICA)

Background: We previously performed a multicenter prospective single-arm trial of 100 patients treated with Axium MicroFX Coils (ev3; Plymouth, Minnesota, USA), AMERICA: Axium MicroFX for Endovascular Repair of IntraCranial Aneurysm study. Initial angiographic and clinical outcomes were excellent. The final results are presented herein.

Methods: AMERICA is a multicenter, prospective single-arm trial evaluating the safety and efficacy of the ev3 Axium MicroFX coil system in 100 separate aneurysms between April 2010 and October 2012. Trial endpoints were 3-6 month angiographic occlusion and clinical status, as reported by treatment center.

Results: Mean follow-up was 157.9 days (median 153.5, range 1-445, SEM 9.3 days). At last follow-up imaging, 90.6% of all aneurysms, 90% of unruptured aneurysms, and 93.3% of ruptured aneurysms had Raymond grade I or II occlusion. Progression to further occlusion (lower Raymond occlusion grade) occurred in 29/85 aneurysms (34.1%). Aneurysm recurrence occurred in 11/85 aneurysms (12.9%). Ninety-nine per cent of patients treated electively and 68.7% of ruptured patients had a modified Rankin score of 0-2. Delayed adverse events (AEs), occurring after discharge and during the follow-up period, occurred in 10% of patients. In total, two AEs (one severe and one moderate) were potentially related to the device, thereby providing a 2% device-related AE rate.

Conclusions: In this prospective, multicenter series of 100 aneurysms treated with Axium MicroFX PGLA (polyglycolic/polylactic acid) coils, 3-6 month angiographic occlusion and clinical outcomes were excellent. This study suggests that Axium MicroFX PGLA coils are safe and effective in the treatment of intracranial aneurysms.