Postinterventional microembolism signals detected by transcranial Doppler ultrasound after carotid artery stenting

Abstract

Background: The occurrence of early post-procedural complications after carotid artery stenting (CAS) can be attributed to embolization of thrombus or plaque particles released from the stented segment. Vascular emboli can be non-invasively detected by transcranial Doppler ultrasound as microembolic signals (MES). We performed this study to discover factors predicting MES detected by transcranial Doppler (TCD)-monitoring within the early post-interventional phase. Patients and methods: In 134 consecutive patients undergoing CAS, transcranial Doppler monitoring of the ipsilateral middle cerebral artery was performed for MES detection during the first post-interventional hour. To identify clinical, morphologic, and procedure-related parameters likely to predict the occurrence of post-interventional MES a logistic regression analysis was performed. Results: In 134 patients (111 male, mean age 69.7 years) relevant MES were detected in 51 patients (38 %) with a median of 4 MES/h and a maximum of 62 MES/h. Three factors were observed to be associated with increased post-interventional MES-counts. These included symptomatic lesion (p < 0.05), elevated total cholesterol (p < 0.05), and aspirin monotherapy (p < 0.0005). In a binary logistic regression model, dual antiplatelet therapy (OR 5.6, p < 0.0005) and asymptomatic lesions (OR 2.6, p < 0.05) were revealed as independent predictors for the absence of post-interventional MES. Conclusions: Post-interventional MES were most likely in symptomatic lesions and patients with elevated cholesterol. The absence of an effective dual antiplatelet therapy and symptomatic lesions were revealed as independent predictors for post-interventional MES. An effective pre-interventional dual antiplatelet and lipid lowering therapy might improve the safety of CAS.