2F21 開発中の多孔薄膜カバードステントとフローダイバーターの生体外模擬循環回路を用いた動脈瘤内血流抑制能の比較

抄録

We have been developing microporous covered stents (MCSs) for the treatment of giant and wide neck intracranial aneurysms (IAs). By shielding IA neck with the microporous cover film, blood flow in IA was stagnated immediately. Subsequently, IA embolization is occurred by thrombus formation with a remarkable decrease of shear rate in IA flow. So, flow reduction performance of device placing is closely related to capability of IA embolization. In this study, we compared the flow reduction performance between MCS and flow diverter (FD), a another type stent for the IA treatment. IA flow was visualized by using in vitro flow simulator and evaluated by particle image velocimetry (PIV). Two-dimensional sidewall IA model was made from acrylic resin. Aneurysm depth, Dome size and neck width of IA model were 9.1 mm, 10.0 mm, 7.1 mm respectively. FD or MCS models were placed at the neck of the aneurysm model. Distributions of flow velocity and shear rate in IA were measured. Before stenting, high shear rate regions spread throughout IA cavity. After stenting, flow velocities in IA model stagnated remarkably. Area mean shear rate in IA flow became about 9 % by FD and 3 % by MCS. Flow reduction performance of MCS was about 3 times higher than the FD.