Endovascular management of subarachnoid hemorrhage due to vertebrobasilar artery dissection using emergency flow-diverter stent placement combined with pseudoaneurysm coiling.

Background: Subarachnoid hemorrhage (SAH) due to intracranial dissecting aneurysm is uncommon and may be challenging to secure when conventional clipping, coiling, or parent artery occlusion are not feasible. Flow-diverter stents have recently emerged as a rescue option in ruptured aneurysms, but their use in the acute phase remains controversial. We report a complex vertebrobasilar dissection presenting with aneurysmal SAH that was successfully treated with emergency flow diversion and adjunctive coiling. Case description: A 54-year-old man with untreated hypertension presented comatose with diffuse SAH. CT angiography and digital subtraction angiography demonstrated a dominant right vertebral artery with a long-segment vertebrobasilar dissection, a large ruptured pseudoaneurysm at the vertebrobasilar junction, and a small aneurysm at the ipsilateral PICA origin, with hypoplastic contralateral vertebral artery. The anatomy precluded clipping, coiling alone, or parent vessel sacrifice. After loading doses of aspirin and clopidogrel, a Derivo2 flow-diverter stent was deployed from the proximal basilar artery to the V4 segment of the right vertebral artery, and the ruptured pseudoaneurysm was selectively coiled. Acute distal in-stent thrombosis was managed with balloon angioplasty and intravenous heparin. The patient awoke promptly and was extubated 6 hours later. Follow-up MRI at 12 hours showed a patent stent, complete exclusion of the pseudoaneurysm, and no SAH progression. Conclusion: This case illustrates that emergency flow diversion with adjunctive coiling can be a feasible strategy for ruptured vertebrobasilar dissecting pseudoaneurysms in carefully selected patients when conventional surgical or endovascular strategies are not feasible.