Purpose This study's goal is to evaluate the safety and efficacy of the Axium Prime Extra Soft (ES) coil for treatment of intracranial aneurysms.

Methods We conducted a retrospective review of all consecutive patients with intracranial aneurysms treated with Axium Prime ES coils at a single center between January 26^th, 2016 and March 28^th, 2017. Baseline patient and aneurysm characteristics, procedural variables and complications were recorded. Aneurysm occlusion at angiographic follow-up was determined using the Roy-Raymond scale. Aneurysm retreatment was recorded.

Results 45 patients with 48 intracranial aneurysms were included, 36 women (80%). Mean age was 58.2 years (median 58 years, 36–92 years). 47 aneurysms were treated successfully with coils (98%). 17 aneurysms were ruptured (35%), 8 recurrent (17%) and 3 symptomatic (6%). Mean maximum aneurysm size was 5.7mm (median 5.2mm, 2.2-26.2mm), mean neck 2.8mm (median 2.6mm, 1-6.2mm), mean dome to neck ratio 1.7 (median 1.4, 0.9-11.5). Aneurysm locations were: 13 anterior communicating artery, 11 middle cerebral artery, 10 internal carotid artery, 5 anterior cerebral artery, 4 posterior communicating artery, 1 basilar tip, and 1 each posterior inferior cerebellar, superior cerebellar, posterior cerebral and persistent hypoglossal arteries. Aneurysm embolization techniques were: 23 balloon-assisted coiling (48%), 11 stent-assisted coiling (23%), 10 simple coiling (21%), 3 Pipeline/coiling (6%), and 1 aneurysm was treated with flow diversion after attempted coiling (2%). Mean total number of coils deployed per aneurysm was 3.5mm (median 3, 1-14). Mean number of Axium Prime ES coils deployed per aneurysm was 2.1mm (median 2, 1-7). Mean Axium Prime ES coil length as total coil length percentage was 55.1% (median 42%, 11.1-100%). Mean packing density was 35.2% (median 35.7%, 1.6-63%). There were 6 peri-procedural complications: 3 coil herniations during balloon-assisted coiling requiring stenting (6%), 1 intra-operative aneurysm re-rupture controlled with balloon inflation (2%), 1 small peripheral subarachnoid hemorrhage on post-operative day 1 (2%), and 1 subacute stent thrombosis on post-operative day 4 (2%). The subacute stent thrombosis resulted in the patient’s death (2.2%). No other treatment-related complication resulted in a permanent neurological deficit or death. Overall mortality was 4.4%. Angiographic follow-up was performed in 19 aneurysms (42%, 26 aneurysms currently pending follow-up). Follow-up was completed with MR angiography in 17 aneurysms (90%) and catheter angiography in 2 aneurysms (10%). Mean time to follow-up was 6.3 months (median 6.1 months, 5.9-7.6 months). At follow-up, 14 aneurysms were completely occluded (74%, Raymond 1) and 5 showed residual neck (26%, Raymond 2). There were no residual aneurysms at follow-up (Raymond 3). No aneurysms were retreated.

Conclusion The Axium Prime ES coil is safe and effective for the treatment of intracranial aneurysms, achieving high packing densities, low risk of major treatment-related complications, high medium-term complete/near-complete aneurysm occlusion rates, and low re-treatment rates.

Disclosures: J. Delgado Almandoz: 2; C; Medtronic Neurovascular. Y. Kayan: 2; C; Medtronic Neurovascular. J. Scholz: None. A. Milner: None. A. Wallace: None. J. Fease: None. M. Mulder: None.