Abstract WP91: Long Term Outcome of Unruptured Large and Giant Aneurysms; a 12 years, Single Center Experience in Consecutive160 Aneurysms

Introduction: Endovascular treatment for large and giant aneurysm is still challenging due to higher recanalization rate and higher complication rate. Intracranial stent for aneurysm treatment was approved in 2010 by Japan government, and treatment strategy for the aneurysms is changing after introduction of intracranial stent. This analysis was to evaluate long-term outcome of unruptured large and giant aneurysms with endovascular treatment retrospectively. Method: In our institute, a total of 202 unruptured large or giant aneurysms were treated from 2003 to 2014. Surgical clipping cases and cases with parent artery occlusion were excluded. Finally, a total of 160 intracranial aneurysms that underwent endovascular coiling were analyzed. Aneurysms were treated by using simple coil embolization or by using adjunctive techniques; i.e., balloon assisted coil embolization, double catheter technique, and stent assisted coil embolization. Results: The mean size was 13.4mm, ranging from 10 to 30.7mm, and average age was 62.1 years old, ranging from 28 to 71 years old. Before stent approval, a total of 93 aneurysms were treated by simple technique, balloon assisted, and double catheter technique: 43%, 41%, 16%, respectively. After stent approval, 67 aneurysms were treated by stent assisted, simple technique, balloon assisted, and double catheter technique: 39%, 9%, 3%, 49%, respectively. Retreatment was performed on 40 patients (25%), and mean aneurysm size of retreatment group was 15.03mm, which was larger compered to that without retreatment (12.4mm). Retreatment rate before stent approval was 29%, in contrast, retreatment rate after stent approval was 19%. Morbidity rate was 5% (8 cases in 160 aneurysms), and mortality rate was 1.2% (2 cases in 160 aneurysms). Conclusion: Retreatment rate was dramatically improved after stent approval. Adjunctive technique, stent assisted coil embolization and double catheter technique, may contribute this favorable results. Morbidity rate and mortality rate was relatively low when compered to previous reports.