Study characteristics
Table 1 shows the demographic characteristics and clinical data of all 22 studies12–33. Regarding their design, these 22 studies included ten randomized controlled trials, six prospective comparative studies, five retrospective comparative studies and one retrospective cohort study. The enrolled studies were published between 2008 and 2019. The total number of interventions was 1578 interventions; with 766 interventions in the endoscopic group, and 812 in the microscopic group.