Radiological and clinical outcomes of endovascular coiling of proximal A1 aneurysms

•Proximal A1 segment aneurysms are rare and difficult to treat.•We evaluated the features and outcomes of endovascular coiling of such aneurysms.•There was a rather high complication rate but no morbidity/mortality association.•The recurrence/retreatment rate of proximal A1 aneurysm coiling was relatively high.•The presence of rupture was significant for recurrence. Aneurysms of the proximal anterior cerebral artery (A1) are rare. Of these A1 aneurysms, proximal A1 aneurysms are among the most challenging for endovascular coiling. This study aimed to evaluate the angiographic features and radiological and clinical outcomes of endovascular coiling of proximal A1 aneurysms. We recruited 38 patients with 38 proximal A1 aneurysms treated with endovascular coiling between September 2005 and April 2016. Baseline patient characteristics, aneurysm morphology, endovascular treatment techniques, immediate post-procedural radiological outcome, and follow-up clinical and radiological outcomes were evaluated, as were risk factors for recurrence. Sixteen proximal A1 aneurysms ruptured (42.1%). Six procedural complications (15.8%), including 5 thromboembolisms and 1 coil migration, were noted. There was no procedural morbidity or mortality. Immediate post-procedural radiological outcomes showed complete occlusion in 23, residual necks in 12, and residual sacs in 3 lesions. Follow-up angiographic outcomes were possible for 28 lesions (73.7%). Follow-up angiography showed sac recurrence in 3 (10.7%) and neck recurrence in 3 (10.7%) lesions. Retreatment was performed in 4 lesions (14.3%); all were treated by endovascular coiling. The presence of aneurysmal ruptures was only significant regarding recurrence in univariate logistic regression analysis. In our study, endovascular coiling of proximal A1 aneurysms was associated with a relatively high rate of procedural complications but not with procedural morbidity and mortality. The recurrence and retreatment rates of endovascular coiling of proximal A1 aneurysms were relatively high, and presence of rupture was significant for recurrence.