Clinical efficacy of hysteroscopic Mirena ring broken-arm slipknot suture fixation for adenomyosis

To evaluate the clinical efficacy and safety of hysteroscopic Mirena ring broken-arm slipknot suture fixation (BA) compared with non-broken-arm slipknot suture fixation (NBA) and Giman ring anchor fixation (Giman) for the treatment of adenomyosis (AM). A total of 102 patients with AM treated from October 2023 to July 2025 were retrospectively enrolled and divided into three groups: BA group ( n = 40), NBA group ( n = 45), and Giman group ( n = 17). Clinical efficacy, pain scores (VAS), menstrual blood loss (PBAC), sex hormone levels (E 2 , FSH, LH), endometrial thickness, and uterine cavity depth were compared using generalized estimating equations (GEE), repeated measures ANOVA, and difference-in-differences (DID) models. Causal forest analysis was applied to estimate individualized treatment effects. Adverse events were assessed by Log-binomial regression. The overall effective rate was 92.50% in the BA group, 84.44% in the NBA group, and 64.71% in the Giman group ( P < 0.05). GEE analysis showed that both the BA and NBA groups had significantly lower PBAC and VAS scores compared with the Giman group across all follow-up time points ( P < 0.05). Repeated measures ANOVA revealed significant interaction effects between treatment method and time on sex hormone levels ( P < 0.001). DID analysis demonstrated that the BA group had the greatest reduction in endometrial thickness and uterine cavity depth. The total adverse event rate was significantly lower in the BA group than in the other two groups (RR < 1, P < 0.05). In this retrospective cohort, hysteroscopic Mirena ring broken-arm slipknot suture fixation was associated with better 12-month clinical outcomes and fewer adverse events compared with the NBA and Giman approaches for treating AM.