Statistical analysis
SD
Data were analysed using SPSS (version 22). Quantitative data are reported as the mean ± SD, and qualitative data as number in percentage. After determination of variable data distribution with Kolmogrov-Smirnov test, comparison between two groups were performed using independent T-test when the data were normally distributed; otherwise the Mann Whitney test was used. In order to compare the data before and after surgery within each group, paired T-test was performed for variables which had normal distribution and Wilcoxon test for variables with non-normal distribution. P values less than 0.05 were considered statistically significant.