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

ObjectiveThe 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.MethodsDuring 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.ResultsCAS 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%.ConclusionCerebral 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. 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. 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. 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%. 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.