One-stage Stent-assisted Coil Embolization for Rupture-side-unknown Bilateral Vertebral Artery Dissecting Aneurysms in an Acute Stage: A Case Report.

Bilateral vertebral artery dissecting aneurysms (VADAs) with subarachnoid hemorrhage (SAH) are rare and their management is still challenging. In this report, we successfully performed one-stage stent-assisted coil embolization (SAC) for bilateral VADAs with SAH in an acute stage, because the ruptured side could not be diagnosed. A 47-year-old woman presented with a sudden onset of headache without laterality, and left-side dominant SAH with bilateral VADAs was noted on computed tomography (CT) scans. The size of aneurysmal dome and neck was similar between the two VADAs, and a bleb was observed only on the right VADA. In computational fluid dynamics (CFD) simulations, findings of wall shear stress (WSS), normalized WSS, and WSS gradient suggested that the left VADA was ruptured, while the oscillatory shear index and aneurysm formation indicator suggested the opposite-side one to be ruptured. Thus, we could not determine which VADA was ruptured by clinical data and CFD analyses. Therefore, we performed simultaneous treatment for the bilateral VADAs by using SAC technique 8 h after the onset under dual antiplatelet and anticoagulation therapies. There was no evidence of rebleeding and stent thrombosis. Stent thrombosis was monitored by duplex color-coded ultrasonography after the intervention. She was discharged without neurological deficits, and 6-month follow-up cerebral angiography demonstrated no recanalization of VADAs. This is the first report showing bilateral VADAs with SAH treated by one-stage SAC within 24 h of SAH, and the potential risks are discussed.