Background Internal carotid artery (ICA) bifurcation aneurysms are uncommon. Therefore, there have been only a few endovascular series on ICA bifurcation aneurysms published to date. The purpose of this study is to report the safety and efficacy of endovascular therapy for ICA bifurcation aneurysms.

Methods There were 25 ICA bifurcation aneurysms (unruptured n=23, ruptured n=2) in 25 patients in this study. There were 14 women, with a mean age of 60.9±10.1 years. All patients underwent endosaccular coil embolization.

Results Aneurysm size and neck size ranged from 2.5 to 10.0 mm (mean 5.4±1.5) and from 1.5 to 4.0 mm (mean 2.7±0.8), respectively. Regarding the clinical outcomes of the 23 patients with unruptured aneurysms, 22 patients had no change in their preprocedural modified Rankin Scale (mRS) score. The other patient died of ventilator associated aspiration pneumonia. Two patients with ruptured aneurysms each had scores of mRS 0. Overall morbidity and death rates were 0% and 4%, respectively. 15 aneurysms were treated with a simple technique. The 10 remaining aneurysms required adjunctive techniques: balloon assisted (n=9) and double catheter (n=1). The immediate anatomical outcomes were complete occlusion (n=19 (76.0%)), residual neck (n=4 (16.0%)) and residual aneurysm (n=2 (8.0%)). The overall follow-up of anatomical outcomes were unchanged (n=14 (63.7%)), improved (n=5 (22.7%)) and recurrence (n=3 (13.6%)). No patient suffered from aneurysmal subarachnoid hemorrhage after endovascular therapy. Thromboembolic events without clinical modification occurred in two patients.

Conclusions Endovascular therapy of ICA bifurcation aneurysms is safe and effective, with a low risk of recanalization and re-treatment.