Angle change of the parent arteries after stent-assisted coil embolization of wide-necked intracranial bifurcation aneurysms

Aim To investigate the angle changes of the parent arteries after stent-assisted coil embolization of wide-necked intracranial bifurcation aneurysms. Materials and methods The adjacent parent arterial angles before and after stent-assisted coil embolization were measured in 38 patients with aneurysms of the anterior communicating artery (ACoAA) and 41 patients with bifurcation aneurysms of the middle cerebral artery (MCABA). Variables were analysed in relation to the angle changes. Results Vascular angles of the parent arteries significantly increased by 27.8° (±18.5°) immediately after stent-assisted coil embolization in 79 cases ( p < 0.001), with 25.7° (±14.8°) in ACoAA and 29.7° (±21.4°) in MCABA, respectively. In 51 (64.6%) cases with follow-up angiography (mean interval 13.5 ± 4.1 months), vascular angles increased by 27.2° (±17.1°) immediately after treatment and further increased by 20.7° (±14.3°) at the last follow-up (all p < 0.001). More acute pre-stent angles of the parent arteries correlated with greater post-stent angle changes ( p = 0.006). Younger age tended to be inversely related to post-stent angle changes ( p = 0.091). Conclusion Stent placement during coil embolization induced significant changes in the aneurysm–parent artery relationship. Further study is needed to elicit the association between angle change of the parent arteries and aneurysmal stability after coil embolization.