Abstract 65: Malignant Emboli On Trans Cranial Doppler During Carotid Stenting Predict Post Procedural DWI Lesions And Are Most Common During Stent And Distal Protection Device Deployment

BACKGOUND: We evaluated the safety of the steps during carotid stenting. METHODS: This was a prospective single-arm study. Cases were monitored by TCD during the stenting procedure. The time of each of 11 steps was recorded and noted during TCD interpretation. Post stenting MRI was done in all patients. Emboli on TCD were classified based on the relative energy index of microemboli (REIM) method into microemboli (REIM ≤ 1) or malignant (REIM >1). Medians were compared using Mann-Whitney test. A negative binomial model was used to investigate the predictive value of TCD findings on new DWI hits. RESULTS: We enrolled 30 subjects. The median age was 70.5 years and 23.3% were asymptomatic. The median count of embolic signals was 212.5 (108 microemboli, 80 malignant). Stent deployment had the highest median count 58 (31 microemboli, 20 malignant) followed by protection device deployment 30 (21 microemboli, 10 malignant, (p value 0.0006)) “Figure”. On post stenting MRI, 80% had new DWI hits. The median DWI count was 4 (range 0-33). The median volume of DWI hits was 0.4 ml (range 0 - 6.1 ml). 63% of patients had a total volume under 1 ml. Only 2 patients (6.7%) had new deficits post stenting. The median DWI volume in those patients was 3.0 ml compared to 0.6 ml in asymptomatic cases (p 0.037). Median emboli count in those with vs. without new deficits was not different (p 0.87) Total TCD emboli count did not predict DWI hits, adjusting for age and symptoms’ status (p 0.25). Malignant emboli predicted new DWI hits (p 0.044). For every malignant embolus, the expected count of DWI hits increases by 1% (CI95 0-2%). There was no relation between total or malignant emboli with the DWI volume. CONCLUSIONS: In this prospective study, we observed a high incidence of emboli on TCD during stenting, especially when stent and protection device were deployed. Most patients developed new DWI hits but only 6.7% had new deficits. The combined DWI volume was less than 1.0 ml in most cases. Only malignant emboli predicted new DWI hits.