RT Journal Article SR Electronic T1 E-234 Single-centre study of endovascular treatment of middle cerebral artery (MCA) aneurysms JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP A156 OP A157 DO 10.1136/neurintsurg-2020-SNIS.265 VO 12 IS Suppl 1 A1 Chia, G A1 Rice, H A1 Jaya Kumar, M A1 Sharma, R A1 Rapier, C A1 Withers, T A1 de Villiers, L YR 2020 UL http://jnis.bmj.com/content/12/Suppl_1/A156.2.abstract AB Purpose To evaluate safety and efficacy of endovascular treatment of MCA aneurysms. Current published data does not clearly demonstrate an advantage with either endovascular treatment or open neurosurgical clipping.Methods and Materials Consecutive patients with ruptured and unruptured MCA aneurysms, treated with endovascular methods in our comprehensive multidisciplinary institution, from January 2008 to September 2019 were included. Database was prospectively acquired and retrospectively analysed. Baseline patient demographics, aneurysm location, size and previous treatments were collected. Imaging follow up was performed at 3 months, 6 months, 18 months, 2 years and 5 years. Data analyses focused on type of device used, procedure-related adverse events, long term angiographic results and clinical outcomes.Results 140 treatments on 124 MCA aneurysms were performed in 111 patients (18 M1, 91 M1/2 bifurcation, 11 M2, 4 M3 or M4 aneurysms). 45% treated were ruptured aneurysms. 66 were treated with coils alone, 5 with stent-assisted coiling, 19 with a combination of coils and flow diverting stents, 47 with flow diverting stents alone, and 3 with WEB devices. Occlusion rates were 81%, 90% and 88% at 6 months, 2 years and 5 years respectively. Specifically, occlusion rates for aneurysms treated with Pipeline flow diverting stents were 92% at 6 months and 100% at 1 year with no subsequent recurrence. All cause procedure-related morbidity was 3.6% (5/140) and mortality 1.4% (2/140).Conclusion Endovascular treatment of MCA aneurysms results in high rates of complete aneurysm occlusion with low rates of complication. Treatment with flow diverting stents have resulted in high durable aneurysm occlusion rates.Disclosures G. Chia: None. H. Rice: 1; C; Medtronic, Stryker, Microvention, Philips, Siemens and GE. 2; C; Medtronic, Stryker, Microvention, Philips, Siemens and GE. M. Jaya Kumar: None. R. Sharma: None. C. Rapier: None. T. Withers: None. L. de Villiers: 1; C; Medtronic, Stryker, Microvention, Philips, Siemens and GE. 2; C; Medtronic, Stryker.