Definition and primary outcomes
Clinical and morphologic features, categorization, and grading of comorbidities as well as outcomes measures were classified accordingly to the reporting standards for carotid interventions appointed by the SVS.16 Carotid stenosis was considered symptomatic if TIA or stroke involving the ipsilateral carotid territory occurred within 6-months of the initial assessment. Carotid cross-clamp intolerance and necessity of shunt insertion was defined as a reduction of >75% in baseline wave values of when using somatosensory-evoked potentials, or >50% reduction of the peak systolic value at the ipsilateral middle cerebral artery at transcranial-Doppler. Severity of the complication and neurologic events were classified accordingly to the SVS guidelines.11,16 Neurologic complications were classified as follow: minor stroke was a new neurologic event that persisted for > 24 hours but completely resolved or returns to baseline within 30 days and changed the National Institutes of Health Stroke Scale (NIHSS) by 2 to 3 points. A major stroke was a new neurologic event that persisted after 3 days and changed the NIHSS by at least 4 points. Specifically for this study, primary outcome was in-hospital mortality. Secondary outcomes were neurologic events rate, and a composite endpoint of stroke/death rate.
Statistical analysis 17
Clinical data were recorded and tabulated in Microsoft Excel (Microsoft Corp – Redmond; Wash – USA) database. Statistical analysis was performed by means of SPSS 26.0 for Windows (IBM SPSS – Chicago; Ill – USA). Categorical variables were presented using frequencies and percentages. Continuous variables were presented with mean ± standard deviation (SD), or median with interquartile range (IQR) and ranges, based on data distribution. Categorical variables were analyzed with the χ2 test, and Fisher’s exact test when appropriate. Continuous variables were tested for normal distribution by the Shapiro-Wilk’s test and compared between groups with unpaired Student’sT -test for normally distributed values; otherwise, the Mann-Whitney U test was used. Tukey’s honest significance test was used as single-step multiple comparisons to find significant difference among means. Univariate analysis was used to identify potential predictors of in-hospital mortality. Associations that yielded a p  value <0.20 on univariate screen were then included in a binary logistic regression analysis using the Wald’s forward stepwise model. The strength of the association of variables with mortality was estimated by calculating the odd ratio (OR) and 95% confidence intervals [(95%CI): significance criteria 0.20 for entry, 0.05 for removal)]. All reported p values were two-sided;p value <0.05 was considered significant.