Postoperative maintenance levonorgestrel-releasing intrauterine system and endometrioma recurrence: a randomized controlled study

BACKGROUND: According to 3 randomized trials, the levonorgestrel-releasing intrauterine system significantly reduced recurrent endometriosis-related pelvic pain at postoperative year 1. Only a few studies have evaluated the long-term effectiveness of the device for preventing endometrioma recurrence, and the effects of a levonorgestrel-releasing intrauterine system as a maintenance therapy remain unclear. OBJECTIVE: The objective of the study was to evaluate whether a maintenance levonorgestrel-releasing intrauterine system is effective for preventing postoperative endometrioma recurrence. STUDY DESIGN: From May 2011 through March 2012, a randomized controlled trial including 80 patients with endometriomas undergoing laparoscopic cystectomy followed by six cycles of gonadotropin-releasing hormone agonist treatment was conducted. After surgery, the patients were randomized to groups that did or did not receive a levonorgestrel-releasing intrauterine system (intervention group, n = 40, vs control group, n = 40). The primary outcome was endometrioma recurrence 30 months after surgery. The secondary outcomes included dysmenorrhea, CA125 levels, noncyclic pelvic pain, and side effects. RESULTS: Endometrioma recurrence at 30 months did not significantly differ between the 2 groups (the intervention group, 10 of 40, 25% vs the control group 15 of 40, 37.5%; hazard ratio, 0.60, 95% confidence interval, 0.27-1.33, P = .209). The intervention group exhibited a lower dysmenorrhea recurrence rate, with an estimated hazard ratio of 0.32 (95% confidence interval, 0.12-0.83, P = .019). Over a 30 month follow-up, the intervention group exhibited a greater reduction in dysmenorrhea as assessed with a visual analog scale score (mean +/- SD, 60.8 +/- 25.5 vs 38.7 +/- 25.9, P < .001, 95% confidence interval, 10.7-33.5), noncyclic pelvic pain visual analog scale score (39.1 +/- 10.9 vs 30.1 +/- 14.7, P = .014, 95% confidence interval, 1.9-16.1), and CA125 (median [interquartile range], -32.1 [-59.1 to 14.9], vs -15.6 [-33.0 to 5.0], P = .001) compared with the control group. The number-needed-to-treat benefit for dysmenorrhea recurrence at 30 months was 5. The number of recurrent cases requiring further surgical or hormone treatment in the intervention group (1 of 40, 2.5%, 95% confidence interval, -2.3% to 7.3%) was significantly lower than that in the control group (8 of 40, 20%, 95% confidence interval, 7.6-32.4%; P = .031). CONCLUSION: Long-term maintenance therapy using a levonorgestrel-releasing intrauterine system is not effective for preventing endometrioma recurrence.