Rescue Surgery in the Flow Diverter Era: Partial Trapping Plus Revascularization Technique for a Giant Carotid-Ophthalmic Aneurysm

BACKGROUND: Flow diverters (FDs) are an excellent option for the management of giant carotid artery aneurysms. However, in a nonnegligible percent of cases, the aneurysm may continue to grow despite multiple endovascular treatments and apparent occlusion on the angiogram. Due to the recent introduction of FDs, surgical experience after their failure is scarce and neurosurgeons have to face these challenging cases without much previous reference. Here we describe a giant ophthalmic-carotid aneurysm that presented with new severe mass effect 5 years after initially successful treatment with FDs and coils. We investigate the likely advantages of partial trapping versus complete trapping in this particular type of case. CASE DESCRIPTION: A 63-year-old patient with a subarachnoid hemorrhage from a 26-mm left carotid-ophthalmic aneurysm was initially embolized with coils. One year later a recanalization was observed and treated with an FD. Five years afterward, the patient's mild cognitive impairment prompted a magnetic resonance image that showed significant aneurysm growth despite apparent occlusion on angiogram. Rescue surgery consisted of partial trapping + extracranial-intracranial bypass and aneurysm debulking. The patient recovered from his deficits and remains asymptomatic 2 years later. CONCLUSIONS: In selected patients with previous long-term FDs, partial trapping may be a choice even if aneurysm debulking is needed. After years of stent placement, some endothelialization and neointimal membrane formation could have a summing effect to facilitate surgical exclusion and enable a safe thrombectomy. Classic revascularization techniques must be rethought and retested in this new FD era scenario.