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ARTICLES: O. O. Zaidat, R. Klucznik, M. J. Alexander, J. Chaloupka, H. Lutsep, S. Barnwell, M. Mawad, B. Lane, M. J. Lynn, M. Chimowitz For the NIH Multi-center Wingspan Intracranial Stent Registry Study Group The NIH registry on use of the Wingspan stent for symptomatic70–99% intracranial arterial stenosis Neurology 2008; 70: 1518-1524 [Abstract] [Full text] [PDF]

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The NIH registry on use of the Wingspan stent for symptomatic 70-99% intracranial arterial stenosis

Thomas W. Leung, Simon C.H. Yu, Wynnie W.M. Lam, Lawrence K.S. Wong   (27 March 2008)

Reply from the authors

Osama O Zaidat, Marc Chimowitz, MD, Emory University, Atlanta, GA   (27 March 2008)

The NIH registry on use of the Wingspan stent for symptomatic 70-99% intracranial arterial stenosis 27 March 2008
Thomas W. Leung, Department of Medicine and TherapeuticsPrince of Wales Hospital, The Chinese University of Hong Kong Shatin, Hong Kong, Simon C.H. Yu, Wynnie W.M. Lam, Lawrence K.S. Wong Send Correspondence to journal: Re: The NIH registry on use of the Wingspan stent for symptomatic 70-99% intracranial arterial stenosis drtleung{at}cuhk.edu.hk Thomas W. Leung, et al.	We read with interest that a relatively high rate of in-stent restenosis (ISR) (25%) was revealed in the NIH Wingspan registry. [1] This figure may not be an overestimate. In our cohort of 40 patients with self-expandable stenting for symptomatic intracranial stenosis, 19 had repeat digital subtraction angiography (DSA) in 12 months. ISR (>50% stenosis) developed in five patients (26.3%) which was apparently independent of cardiovascular risk factor control. ISR may be more frequent in daily practice than the rate in the Wingspan phase I study. [2] Although most patients with ISR remain asymptomatic, neo-intimal hyperplasia in intracranial vasculature may not be as benign as the authors suggested. [1] In a coronary model, ISR may cause branch occlusion and symptom recurrence. [3] In cerebral circulation, neo-intimal proliferation may similarly occlude perforators arising from middle cerebral artery (MCA) or basilar artery (BA) and cause infarction in the perforator territory where collateral is minimal. Furthermore, given the small luminal diameter of intracranial vessels, ISR predisposes to perfusion failure apart from thrombo-embolic risk. ISR could be an important factor governing the long-term outcome after intracranial stenting. A randomized trial is warranted to investigate the efficacy of stenting in symptomatic intracranial stenosis, and it is encouraging to know that one is currently planned in the US. [1] In a country where intracranial stenosis is particularly prevalent, we have been conducting a pilot, randomized study comparing optimal medical treatment vs early adjunctive self-expandable stenting in patients with high risk of recurrence (i.e., recent cerebral ischemic event attributed to a high-grade (>70%) intracranial stenosis). Some issues encountered during the planning of our study may warrant discussion. First, we randomized patients based on digital subtraction angiography (DSA) rather than CT angiography (CTA). CTA is invaluable for screening, but is insufficient to accurately quantify the severity of stenosis. In a few patients who had initially consented to the study, subtle vascular anomalies adjacent to the stenosis (like fenestrated MCA or BA) could only be revealed in three-dimensional reconstruction of DSA but not in CTA. Catastrophic complications may have occurred if CTA alone was relied upon. Secondly, although double anti-platelet regimen has not been shown to be more effective than single anti-platelet treatment in symptomatic intracranial stenosis, combination therapy has been shown to decrease microembolic signal in symptomatic carotid stenosis. [4] To avoid this potential confounder, patients in both stenting and medical groups are offered dual anti-platelets. References 1. Zaidat OO, Klucznik R, Alexander MJ, et al. The NIH registry on use of the Wingspan stent for symptomatic70¡V99% intracranial arterial stenosis. Neurology 2008; 0: 01.wnl.0000306308.08229.a3v1 (accessed March 11, 2008) 2. Levy EI, Turk AS, Albuquerque FC, et al. Wingspan in-stent restenosis and thrombosis: incidence, clinical presentation, and management. Neurosurgery 2007;61: 644-651. 3. Weintraub WS. The Pathophysiology and Burden of Restenosis. The American Journal of Cardiology 2007; 5 (Supplement 1):S3-S9. 4. Markus HS, Droste DW, Kaps M, et al. Dual antiplatelet therapy with clopidogrel and aspirin in symptomatic carotid stenosis evaluated using doppler embolic signal detection: the clopidogrel and aspirin for reduction of emboli in symptomatic carotid stenosis (CARESS) trial. Circulation 2005;111:2233-2240. Disclosure: The authors report no disclosures.
Reply from the authors 27 March 2008
Osama O Zaidat, Medical College of Wisconsin Department of Neurology, 9200 W Wisconsin Ave, Milwaukee WI 53226, Marc Chimowitz, MD, Emory University, Atlanta, GA Send Correspondence to journal: Re: Reply from the authors szaidat{at}mcw.edu Osama O Zaidat, et al.	We thank Dr. Leung et al for their insightful comments and their interest in the NIH Wingspan intracranial stent registry study article. [1] The authors raise several important issues. The group provided their local experience with re-stenosis after intracranial stenting with a self-expanding stent and report a re-stenosis rate of (5/19, 26.3%) which is similar to the rate we found. [1] Although most cases of re-stenosis were asymptomatic in our registry, we recognize the short follow-up of most patients in this registry (mean follow-up was only 5.8 months) does not exclude the possibility that some of these stenoses could become symptomatic over a longer follow-up period. We agree that longer follow-up of a larger cohort of patients who undergo intracranial stenting is necessary to clarify this issue. This will be achieved in the randomized trial comparing stenting with medical therapy in patients with intracranial stenosis that our group will be initiating in the US in 2008. In the Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) trial, 764 patients (382 patients in each arm) will be followed for a mean period of approximately 2 years. We also agree that it is important to confirm intracranial stenosis by catheter angiography and the use of dual anti-platetelet therapy in clinical trials evaluating the safety and efficacy of stenting. In SAMMPRIS, conventional digital subtraction angiography evidence of 70-99% intracranial arterial stenosis will be required for eligibility for the trial and aspirin and clopidogrel will be used for 90 days after enrollment in both treatment arms followed by aspirin monotherapy. Disclosure: Dr. Zaidat consults for Boston Scientific Inc., the manufacturers of the Wingspan stent. Dr. Chimowitz reports no disclosures.