Overview of evidence on risk factors and early management of acute carotid stent thrombosis during the last two decades

Objective: Acute carotid stent thrombosis (ACST) occurring in the first hours after the procedure is an exceedingly rare complication of carotid artery stenting, but it is potentially devastating. This review aimed to evaluate current literature, identifying all reported cases during the last two decades, with the final purpose of reporting predictive factors and early management. Methods: A systematic review and meta-analysis was conducted according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Results: A total of 464 potentially relevant articles were selected. After review of records at title and abstract level, 29 articles with60patientswere included. Twelve studies reportedonACST incidence rate intheir cohorts, rangingfrom0.36% to as high as 33%. In considering etiology, antiplatelet noncompliance or resistance is the most frequently reported risk factor. Emergency procedures seemed to be associatedwith greater risk for ACST, reaching 5.6% to 33% incidence. Dual-layer stentswere also associated with greater risk (45% vs 3.7%; P=.0001; odds ratio, 21.3). Use of an overlapping stent as a bailout procedure because of dissection, malposition, or long lesions was correlated with increased risk (7.3% vs 0.002%), as were long stenotic lesions (22.9+/-6.83mmvs 14.2+/-6.42mm; P=.0034) and stent length (3.8+/-0.4 cmvs 2.8+/-0.86 cm; P=.0055). ACST was associated with neurologic status deterioration in 56.7% of cases. Time to symptoms or ACST diagnosis had a median of 1.5 hours, with 30% occurring intraprocedurally. In asymptomatic ACST, conservative management was unanimous. Endovascular treatment was the most common approach to intraprocedural ACST. Surgical options included carotid endarterectomy with stent explantation (n= 9), which was also a bailout after failed endovascular treatment in two cases. Conclusions: ACST incidence is higher in emergent, neurologically unstable patients. Antiplatelet noncompliance, antiplatelet resistance, long stenotic lesions, use of more than one stent, and dual-layer stents are also associated with increased risk. The decision as to the best approach depends on whether ACST occurs intraprocedurally or afterward, the development of neurologic status deterioration, and the center's experience. However, additional studies must be undertaken to better define optimal management.