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

ABSTRACT Background Flow-diverters (FDD) are an excellent option for the management of giant carotid artery aneurysms. However, in a non-negligible 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 FDD, 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 FDD and coils. We investigate the likely advantages of partial trapping vs. complete trapping in this particular type of case. Case Description A 63-year-old patient with a subarachnoid hemorrhage from a 26mm left carotid-ophthalmic aneurysm was initially embolized with coils. One year later a recanalization was observed and treated with FDD. Five years after FDD, patient’s mild cognitive impairment prompt an MRI that show significant aneurysm growth despite apparent occlusion on angiogram. Rescue surgery consisted of partial trapping + EC-IC bypass and aneurysm debulking. The patient recovered from his deficits and remains asymptomatic 2 years later. Conclusions In selected patients with previous long-term FDD, 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 FDD era scenario.