Endovascular embolization.As per the usual neurointerventional approach to avms, we positioned a microcatheter (a 167 cm headway duc) close to the avm in preparation for embolization with a liquid embolic agent known as onyx.Onyx functions as a sort of injectable glue, and embolization of brain avms is an on-label use of this product.Further the headway duo is marketed for its compatibility with onyx and dmso (an agent used in conjunction with onyx).The embolization went as planned, and the avm appeared to be completely eliminated.Upon attempting to remove the microcatheter from the hardened onyx, again in the standard fashion, the microcatheter fractured.We noted that the retrieved portion of the microcatheter accounted for almost its entire length, and therefore that the retained fragment of microcatheter was small and likely embedded in the onyx, where it would cause no harm.The case was therefore concluded and the pt awoken from anesthesia.She awoke normally and was again noted to be neurologically intact.Approx 1 hr later, the pt experienced a clinical deterioration.Head ct was performed emergently and demonstrated high density material in the basilar artery.We then performed an emergency angiogram which demonstrated occlusion of the basilar artery, followed immediately by a prolonged attempt to remove the forming blood clot within the basilar artery.These efforts were ultimately unsuccessful.The pt was transferred to the neurological intensive care unit for close monitoring and blood pressure control.Mri performed the day after the procedure demonstrated abnormal metallic artifact, suggesting that a long length of the metallic coil that forms the inner portion of the microcatheter was retained, far exceeding the length of the retained outer layer of the microcatheter.This coil is presumed to have acted as a nidus for subsequent clot formation.Unfortunately, the pt died two days after the procedure from complications of a cerebellar and brain stem infarction.The proximate cause for this pt's demise was occlusion of the basilar artery and its branches.This in turn was caused by fracture and fragmentation of the microcatheter inside the pt's brain arteries following onyx embolization, including in particular a relatively unk failure mode wherein different layers of the microcatheter are retained to different degrees.
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