P–302 Levonorgestrel-releasing intrauterine device (LNG-IUD) for symptomatic endometriosis following surgery: a Cochrane systematic review
Authors: Gibbons T , Georgiou E , Al-Inany H , Cheong Y 
Published: August 2021

Abstract

Study question
Does levonorgestrel-releasing intrauterine device (LNG-IUD) improve post-operative outcomes for endometriosis when compared to other systemic hormonal treatments or no additional treatment?

Summary answer
We are uncertain whether LNG-IUD has an impact on dysmenorrhoea when compared to no postoperative treatment or post-operative GnRH agonists (GnRH-a).

What is known already
Endometriosis is a condition characterised by the presence of ectopic deposits of endometrial-like tissue outside the uterus, usually in the pelvis; inducing a chronic inflammatory response which can lead to pelvic pain and infertility. Various treatment options exist including surgical treatment, ovarian suppression therapy, or a combination of these strategies. The impact of laparoscopic treatment on overall pain is uncertain and a significant proportion of women will require further surgery. Therefore, adjuvant medical therapies such as LNG-IUD have been considered to reduce treatment failure and recurrence of symptoms.

Study design, size, duration
A Cochrane systematic review and meta-analysis was performed. Electronic searches of the Cochrane Gynaecology and Fertility Specialised Register of Controlled Trials, CENTRAL, MEDLINE, EMBASE, PsycINFO, CINAHL and Epistemonikos were conducted to January 2021 for relevant randomised controlled trials (RCTs). Two independent authors screened studies and extracted data. Risk ratios (RR) were calculated for dichotomous data and standardised mean differences (SMD) for continuous data, with 95% confidence intervals (CI). Heterogeneity was examined via the I² statistic.

Participants/materials, setting, methods
Participants: women undergoing surgical treatment for endometriosis without hysterectomy
Intervention: LNG-IUD insertion within three months of surgery
Comparison: No postoperative treatment, placebo IUD or any other systemic treatment
Primary outcome: overall pain
Secondary outcomes: improvement of the most troublesome symptom, dysmenorrhoea, quality of life, satisfaction with treatment and adverse events. Primary analysis was conducted on data per woman randomised.

Main results and the role of chance
Four RCTs were included, with a total of 157 women. Five studies are awaiting classification and one is an ongoing study. We corresponded with original study authors to clarify missing outcome data. No studies reported on overall pain or improvement in the most troublesome symptom. We await study author clarification on quality of life and treatment satisfaction data. We are uncertain whether LNG-IUD improves dysmenorrhoea compared to no postoperative treatment at 12 months. Data on this outcome were reported on by 2 RCTs, but were expressed as median and inter-quartile range and so meta-analysis was not possible (RCT 1: delta of median visual analog scale (VAS) 81 versus 50, p = 0.006, n = 55; RCT 2: fall in VAS by 50 (35–65) p = 0.012 versus 30 (25– 40), p = 0.021, n = 40). We are uncertain whether compared to post-operative GnRH-a, LNG-IUD affects rates of dysmenorrhoea at 6 months (VAS SMD 0.79, 95% CI –0.08 to 1.67, p = 0.08, one RCT, n = 22, very low quality evidence). Various adverse events with LNG-IUD were reported including irregular bleeding and weight gain. However, due to a lack of raw data and comparable studies, we were unable to undertake meta-analysis.

Limitations, reasons for caution
The major limitation of this systematic review was that there were insufficient studies reporting on our prespecified outcomes, including our primary outcome. In addition, the included studies were not all of high quality with limited long-term follow-up.
Wider implications of the findings: This systematic review highlights the paucity of RCTs reporting outcomes included in the new core outcome set for endometriosis research. Further high-quality RCTs are needed to assess postoperative adjuvant hormonal therapy and these should prioritise investigating key endometriosis outcomes such as overall pain, quality of life and treatment satisfaction.

Trial registration number
Not applicable