OBJECTIVE: To evaluate the efficacy and safety of retaining a balloon stent in the uterus for 8 weeks to prevent adhesion reformation after hysteroscopic adhesiolysis. DESIGN: A single-center randomized controlled study. SUBJECTS: A total of 160 women with severe intrauterine adhesions (American Fertility Society intrauterine adhesion scores ≥9 and European Society for Gynaecological Endoscopy grade ≥IV). INTERVENTION: The participants were randomized 1:1 into two groups. In the study group, the balloon stent was left in place for 8 weeks after surgery and removed at the second-look hysteroscopy, with a third-look hysteroscopy performed 4 weeks later. In the control group, the balloon stent was maintained for 1 week, with participants undergoing second- and third-look hysteroscopies at 4 and 8 weeks postoperatively, respectively. Among 160 randomized patients, 136 (69 and 67 in the study and control groups, respectively) completed the study. MAIN OUTCOME MEASURES: The primary outcome was the adhesion recurrence rate on third-look hysteroscopy. RESULTS: On third-look hysteroscopy, the adhesion reformation was significantly lower in the study group than in the control group (17.4% vs. 43.3%
relative risk, 0.40
95% confidence interval, 0.22-0.72
rate difference, -25.89%
95% confidence interval, -40.75% to -11.04%). Additionally, the reduction in American Fertility Society adhesion scores was significantly larger in the study group than in the control group (10 vs. 7). The outcomes of the second- and third-look hysteroscopies were consistent. No safety concerns were observed regarding extended stent placement. CONCLUSION: In this randomized controlled study, extending the balloon stent application to 8 weeks proved an effective and safe method for preventing adhesion reformation after hysteroscopic adhesiolysis for severe intrauterine adhesions.