Statistical analysis
The primary hypothesis of the current study was that children who received a perioperative exercise intervention beginning within 24 h postoperatively would show significantly higher 6MWD than those who received routine nursing and treatment. According to our pre-experiment, based on a two-sided t-test with an All statistical analyses were performed using SPSS software version 22.0 (IBM Corp., Armonk, NY, USA). Enumeration data are expressed as the number of cases and rates (%), and comparisons between groups of enumeration data were performed using the 