Clinical Investigative Study Thromboembolic Events Associated with Neuroform Stent TM in Endovascular Treatment of Intracranial Aneurysms Abutaher M. Yahia, MD, Julius Latorre, MD, Vickie Gordon, NP, PhD, John Whapham, MD, Ali Malek, MD, Richard D. Fessler, MD From the Department of Neurology, Neurosurgery and Radiology, Upstate Medical University, Syracuse, NY (AMY, LJG); Department of Neurosurgery, Providence Hospital, Southfield, MI (AMY, VG, JW, AM, RDF). Keywords: Wide-necked intracranial aneurysms, fusiform aneurysm, Neuroform stent TM -assisted coiling, thromboembolic events, clinical compli- cations. Acceptance: Received September 11, 2008, and in revised form April 16, 2009. Accepted for publication May 9, 2009. Correspondence: Address correspon- dence to Abutaher M. Yahia, MD, Up- state Medical University, SUNY, 750 E Adams Street, Syracuse, NY 13210. E-mail: yahia25@hotmail.com. J Neuroimaging 2010;20:113-117. DOI: 10.1111/j.1552-6569.2009.00390.x ABSTRACT BACKGROUND The incidence of thromboembolic events associated with Neuroform stent TM (Boston Scientific Target, Fremont, CA) is known from previous studies but there are uncertainties of scale. PURPOSE To report our rate of ischemic events associated with Neuroform stent TM . METHODS Consecutive patients treated with Neuroform stent TM for intracranial aneurysms were prospectively enrolled from January 2003 to August 2006. Thromboembolic events as well as clinical outcomes were measured. Mean follow-up was 12 months. RESULTS Successful stent deployment was achieved in (65/67) 97% of patients without any is- chemic event. However, postoperative thromboembolic events were observed in 3 patients despite being on clopidogrel and aspirin. These 3 patients demonstrated poor platelet in- hibitions in platelet aggregation (aggregometry) studies, and were successfully treated with intravenous eptifibatide with good outcome. The majority of the patients had good outcomes [Glasgow Outcome Score (GOS) 5 or National Institute of Health Stroke Scale (NIHSS) 0 in (63/67) 94%, GOS 4 or NIHSS 2 in 1 patient, and GOS 3 or NIHSS 4 was observed in 3 cases]. CONCLUSION Our study reveals that the thromboembolic events associated with Neuroform stent TM may present in a delayed fashion. These events can be successfully treated with good out- come. Therefore, postoperative close follow-up is strongly recommended for all Neuroform stent TM -treated patients. Introduction The wide-necked, large, and giant aneurysms may pose challenge on the traditional endovascular treatment of aneurysms. 1,2 In 1 study, 2 401 patients with 455 aneurysms were treated with Guglielmi detachable coils (GDC). Com- plete coil occlusion of the aneurysm was achieved in 70.8% for small aneurysms (<10 mm) with small neck, 31.2% for small aneurysms with wide neck, 35% for large aneurysms (≥10 mm but ≤25 mm), and 50% of giant aneurysms (≥25 mm). The obstacles of primary complete occlusion of an aneurysm by the endovascular approach had been overcome significantly due to the evolution of new devices and techniques such as 3-dimensional coils and balloon-assisted remodeling of the aneurysms. 3-10 However, the long-term durability after coiling and neck residual remains a barrier 2,10-14 for endovascular coil- ing of aneurysms. The use of stents to overcome the challenge of current endovascular technique had been addressed 15 and yet needs further evaluation and elaboration. The widespread use of balloon-mounted coronary stents was limited due to its less flexible, high-profile nature, poor navigation capabilities in the tortuous cerebral blood vessels, and potential risk of vessel dissection or rupture, as well as delayed stenosis. 16-19 Therefore, to minimize these barriers, focus had been shifted to develop a self-deployed stent, which would be flexible enough to navigate through the tortuous cerebral vascular architecture and tough enough to hold its configuration when encountered by a coil mass. The Neuroform stent TM (Boston Scientific Tar- get, Fremont, CA), a nickel-titanium alloy, possesses a high degree of elasticity and deformability and has been approved under a humanitarian device exemption by Food and Drug Copyright ◦ C 2009 by the American Society of Neuroimaging 113