Abstract Number ‐ 137: Delayed aneurysmal rupture of a giant fusiform vertebrobasilar aneurysm after flow‐diversion embolization with adjunctive coiling

IntroductionVertebrobasilar aneurysms carry a high risk of operative morbidity and high mortality risk with rupture. Treatment with flow diversion embolization has gained popularity. While adjunctive coiling may lower the risk of delayed aneurysm rupture (DAR), DAR can occur during stent endothelialization. describe a case of DAR following flow diversion with adjunctive coil embolization of a giant vertebrobasilar aneurysm and review the literature to further characterize this phenomenon.MethodsPubMed was queried using search terms: “delayed,” “aneurysm,” “rupture,” “flow diverter,” “flow diversion,” and “flow diverting stent” yielding 220 results. There were 47 studies describing 89 patients with DAR after flow diversion.ResultsA forty‐five‐year‐old male presented with posterior fossa compression symptoms secondary to a 30‐mm fusiform basilar artery aneurysm, which grew during short‐interval follow‐up to 35 mm. The patient consented to endovascular embolization. Tri‐axial catheter access system was used to deploy seven telescoping flow diverters from the basilar tip to the intradural left vertebral artery, and nine coils were subsequently deployed in the aneurysm dome. The right vertebral artery was coil embolized. The procedure was uncomplicated and the patient was continued on dual‐antiplatelet therapy. Four weeks later, the patient became unresponsive with absent brainstem reflexes, workup revealed diffuse subarachnoid hemorrhage with intraventricular hemorrhage. Digital subtraction angiography demonstrated contrast extravasation at the aneurysm neck. He succumbed to his neurological injury two days later. Out of 89 patients with DAR after flow diversion, only 3 occurred in fusiform basilar aneurysms treated with adjunctive coil embolization. Only one case, a 37.1‐mm aneurysm treated with 3 flow diverters with adjunctive embolization, occurred at greater than 30 days post‐intervention.ConclusionsThis case highlights the need to better characterize the role of adjunctive coiling with flow diversion for large or giant aneurysms, and to better understand risk factors related to delayed aneurysm rupture.