Statistical analysis
The variables were investigated using visual (histograms, probability
plots) and analytical methods (Kolmogorov–Smirnov/Shapiro–Wilk test)
to determine the normality of their distribution. Normally distributed
continuous variables were expresses as mean ± standard deviation (SD) or
median values with range if not normally distributed. Categorical
variables were expressed as number and percentages. Demographic
parameters, operating variables and follow-up data were compared using
the Mann-Whitney U test and chi-square test. Wilcoxon test was conducted
to analyze pre-operative and follow-up diameter of aneurysm sac.
Kaplan-Meier analysis was conducted to demonstrate freedom from
all-cause mortality and freedom from secondary interventions. The hazard
ratio (HR) and 95% confidence intervals (CI) were estimated with
different Cox proportional hazard models to estimate the independent
predictors of survival with adjustment of the predefined possible rick
factors. A p value of < 0.05 was considered to be
statistically significant, and all statistical analyses were performed
using the SPSS for Windows version 15.0 statistical software program
(SPSS Inc., Chicago, IL, USA).