The characteristics of studies
In the ten retrospective studies, which involved 1606 patients in total, seven studies were performed at a single center, the other three studies were performed at multiple centers. No RCT was identified. These studies were published between 2011 and 2020, and five of them were conducted in America (n=1353), two in Italy (n=172), one in China (n=81), one in England (n=13), and one in Canada (n=15). The minimum follow-up time in the study was 2 years and the maximum was 14 years. The gender ratio (male/female) ranged from 12/23 to 48/34, and the mean age at surgery varied from 0.59 to 32.00 months. Meanwhile, the mean length of hospital stay (days) ranged from 1.64 to 19.09, the mean operative time (min) ranged from 105.77 to 187.62 and the mean chest tube duration (days) ranged from 1.53 to 7.6. The main characteristic of each study included is summarized in the following Table 2.