Usefulness of the Neuroform Stent for the Treatment of Cerebral Aneurysms: Results at Initial (3–6-mo) Follow-up

Abstract

Abstract OBJECTIVE: The Neuroform microstent, a flexible, self-expanding, nitinol stent specifically designed for use in the cerebral vasculature, became available in North America for aneurysm treatment in November 2002. The present report details our experience with the Neuroform stent over the past 2 years, with an emphasis on evolving treatment strategies and treatment durability at initial (3–6 mo) follow-up. METHODS: All patients included in this report were registered in a prospectively maintained database. We assessed the clinical history, indications for stent use, aneurysm dimensions, technical details of the procedures, degree of aneurysm occlusion, angiographic and clinical findings at follow-up, and complications. RESULTS: Over a 20-month period, 64 patients with 74 aneurysms were treated with 86 Neuroform stents. Of 64 patients, 16 (25%) were treated in the context of subarachnoid hemorrhage (8 acute, 7 subacute, 1 remote). Indications for stent use included broad aneurysm neck (n = 51 stents; average neck, 5.1 mm; aneurysm size, 8.2 mm), fusiform/dissecting morphology (n = 17), salvage/bailout for coils prolapsed into the parent vessel (n = 7), and giant aneurysm (n = 11). Sixty-one aneurysms were stented and coiled with complete or near complete (>95%) occlusion in 28 patients (45.9%) and partial occlusion (<95%) in 33 patients (54%). Follow-up angiographic (n = 43) or magnetic resonance angiographic (n = 5) data (average follow-up, 4.6 mo; median, 4 mo; range, 1.5–13 mo) for 48 aneurysms (46 patients) after stent-supported coil embolization demonstrated progressive thrombosis in 25 patients (52%), recanalization in 11 patients (23%) (8 of whom were retreated), and no change in 12 patients (25%). Follow-up angiography in 5 additional patients with dissecting aneurysms treated with stents alone demonstrated interval vascular remodeling with decreased aneurysm size in all patients. Delayed, severe, in-stent stenosis was observed in 3 patients, 1 of whom was symptomatic and required angioplasty and subsequently superficial temporal artery-to-middle cerebral artery bypass surgery. Using the second-generation Neuroform2 delivery system (n = 53), very few technical problems with stent delivery and deployment have been encountered (n = 2). CONCLUSION: The Neuroform stent facilitates adequate embolization of complex cerebral aneurysms, which would not otherwise be amenable to endovascular therapy. Initial follow-up data indicate favorable progressive thrombosis and recanalization rates for aneurysms after Neuroform stent-assisted embolization. These advantages of stenting were most evident for small aneurysms with wide necks.