Randomized clinical trial of open-cell vs closed-cell stents for carotid stenting and effects of stent design on cerebral embolization

Objective: The effect of stent design on cerebral embolization has not been established. The purpose of this trial was to contrast the incidence of subclinical cerebral embolization in high-risk patients undergoing carotid artery stenting (CAS) with open-cell vs closed-cell stents. Methods: During an 18-month period, 40 patients were randomized (1:1) to undergo CAS with open-cell (Acculink, n = 20) or closed-cell stents (Xact, n = 20). A single filter device for embolic protection (Accunet filter) was used. Transcranial Doppler (TCD)-detected microembolic signals (MES) during CAS and preprocedural and 24-hour postprocedural diffusion-weighted magnetic resonance imaging (DW-MRI) were used to determine cerebral embolization. Univariate and nonparametric analyses were used to assess associations between stent design and cerebral embolization. Results: CAS was performed in 17 symptomatic patients (43%) and 23 asymptomatic patients (57%) with a similar number of open-cell and closed-cell stents (9/8 and 11/12, respectively). The total and poststenting median ipsilateral MES counts detected by TCD were 264 (interquartile range [IQR], 222-343) and 48 (IQR, 41-66) for open-cell stents and 339 (IQR, 163-408) and 53 (IQR, 23-88) for closed-cell stents, respectively (P > .56). New acute cerebral emboli detected with DW-MRI occurred in 53% and 47% of patients undergoing CAS with open-cell and closed-cell stents, respectively (P = 1.0). The total and ipsilateral median numbers of DW-MRI lesions between groups were not statistically significantly different (ie, 2 [IQR, 0-4] and 1 [IQR, 0-3] for open-cell stents and 1 [IQR, 0-3] and 1 [IQR, 0-2] for closed cell-stents, respectively; P > .4). One asymptomatic patient undergoing CAS with an open-cell stent sustained a minor stroke; the 30-day stroke-death rate in this series was 2.5%. Conclusion: Cerebral embolization, as detected by TCD and DW-MRI, occurs with similar frequency after CAS with open-cell and closed-cell stents. This randomized trial does not support the superiority of any stent design with respect to cerebral embolization.