Delayed collapse of flow diverter due to acute severe vasospasm: another concern for flow diversion in ruptured aneurysms.

In vivo morphological change of flow diverter stents (FDS) is a known phenomenon and can be seen secondary to various device- and vasculature-related factors such as improper sizing of the device, twisting of the device in tortuous anatomy, insufficient proximal landing zone, and insufficient chronic resistive force of the stent, etc. However, we have encountered a case where severe vasospasm due to aneurysmal subarachnoid hemorrhage led to the collapse of the proximal end of the FDS. Development of vasospasm and consequent possible failure of the device should be taken into consideration when planning flow diversion in ruptured aneurysms.