Statistical analysis:
Statistical analysis were performed with SPSS StatisticsĀ® software (IBM
Corporation, New York, USA). Categorial variables were expressed as
numbers and percentages. Continuous variables were reported as mean +/-
standard deviation (SD) and median with interquartile range (IR) when
appropriated. Event-free survival curves were calculated using the
Kaplan-Meier method. Univariate analysis was performed by comparing the
Kaplan-Meier survival curves using the Log-Rank test to identify risk
factors of late re-operation of the PH. Multivariate analysis was
performed to identify independent risk factors of late re-operation of
the PH, using a Cox regression model. P value <0.05 was
retained for statistical significance.