Risk Index for Predicting Shunt in Carotid Endarterectomy

Background To prevent ischemia during carotid endarterectomy, a routine or selective shunt can be set up in cases of insufficient cerebral perfusion during the carotid clamping. The aim of this study was to analyze predictive factors for shunting under locoregional anesthesia and to validate a risk index to predict shunt. Methods Using a prospective database, we studied carotid endarterectomy performed under locoregional anesthesia between January 1, 2003, and December 31, 2010 ( n  = 1,223). A shunt was used because of clinical intolerance of clamping in 88 cases (group S, 7.2%). Clinical, comorbidities, demographics, and duplex scan data were used to compare group S to a control group (group C, n  = 1,135, 92.8%). A multivariable logistic regression was performed to identify predictors of shunt. Coefficients were assigned to each predictor to propose a predictive score. Results Patients in group S were significantly older than those in group C (75.6 ± 7.8 years vs. 72.6 ± 9.4 years, P P P  = 0.016), occlusion of the contralateral carotid artery (OR = 6.03, 95% CI: 2.91–12.48, P P  = 0.037). The mean flow in the contralateral common carotid artery was 696.5 ± 298.0 mL/sec in group S and 814.7 ± 285.5 mL/sec in group C ( P 15%) groups. Conclusions We have established the first version of a score that predicts the need for a shunt by studying factors associated with intolerance to clamping. The relevance of this score, validated in our series, must be confirmed and adjusted by studies based on a larger sample size.