Levonorgestrel-releasing intrauterine device (LNG-IUD) for symptomatic endometriosis following surgery

Endometriosis is a condition characterised by the presence of ectopic deposits of endometrial-like tissue outside the uterus, usually in the pelvis. The impact of laparoscopic treatment on overall pain is uncertain and a significant proportion of women will require further surgery. Therefore, adjuvant medical therapies following surgery, such as the levonorgestrel-releasing intrauterine device (LNG-IUD), have been considered to reduce recurrence of symptoms.  OBJECTIVES: To determine the effectiveness and safety of post-operative LNG-IUD in women with symptomatic endometriosis.

We searched the following databases from inception to January 2021: The Specialised Register of the Cochrane Gynaecology and Fertility Group, CENTRAL (which now includes records from two trial registries), MEDLINE, Embase, PsycINFO, LILACS and Epistemonikos. We handsearched citation lists of relevant publications, review articles, abstracts of scientific meetings and included studies. We contacted experts in the field for information about any additional studies.

We included randomised controlled trials (RCTs) comparing women undergoing surgical treatment of endometriosis with uterine preservation who were assigned to LNG-IUD insertion, versus control conditions including expectant management, post-operative insertion of placebo (inert intrauterine device), or other medical treatment such as gonadotrophin-releasing hormone agonist (GnRH-a) drugs.

Two review authors independently selected studies for inclusion, and extracted data to allow for an intention-to-treat analysis. For dichotomous data, we calculated the risk ratio (RR) and 95% confidence interval (CI) using the Mantel-Haenszel fixed-effect method. For continuous data, we calculated the mean difference (MD) and 95% CI using the inverse variance fixed-effect method.

Four RCTs were included, with a total of 157 women. Two studies are ongoing. The GRADE certainty of evidence was very low to low. The certainty of evidence was graded down primarily for serious risk of bias and imprecision. LNG-IUD versus expectant management Overall pain: No studies reported on the primary outcome of overall pain. Dysmenorrhoea: We are uncertain whether LNG-IUD improves dysmenorrhoea at 12 months. Data on this outcome were reported on by two RCTs; meta-analysis was not possible (RCT 1: delta of median visual analogue scale (VAS) 81 versus 50, P = 0.006, n = 55; RCT 2: fall in VAS by 50 (35 to 65) versus 30 (25 to 40), P = 0.021, n = 40; low-certainty evidence). Quality of life: We are uncertain whether LNG-IUD improves quality of life at 12 months. One trial demonstrated a change in total quality of life score with postoperative LNG-IUD from baseline (mean 61.2 (standard deviation (SD) 14.8) to 12 months (mean 70.3 (SD 16.2) compared to expectant management (baseline 55.1 (SD 17.0) to 57.0 (SD 33.2) at 12 months) (n = 55, P = 0.014, very low-certainty evidence). Patient satisfaction: Two studies found higher rates of satisfaction with LNG-IUD compared to expectant management; however, combining the studies in meta-analysis was not possible (n = 95, very low-certainty evidence). One study found 75% (15/20) of those given post-operative LNG-IUD were "satisfied" or "very satisfied", compared to 50% (10/20) of those in the expectant management group (RR 1.5, 95% CI 0.90-2.49, 1 RCT, n=40, very low-certainty evidence). The second study found that fewer were "very satisfied" in the expectant management group when compared to LNG, but there were no data to include in a meta-analysis.  Adverse events: One study found a significantly higher proportion of women reporting melasma (n = 55, P = 0.015, very low-certainty evidence) and bloating (n = 55, P = 0.021, very low-certainty evidence) following post-operative LNG-IUD. There were no differences in other reported adverse events, such as weight gain, acne, and headaches.  LNG-IUD versus GnRH-a Overall pain: No studies reported on the primary outcome of overall pain. Chronic pelvic pain: We are uncertain whether LNG-IUD improves chronic pelvic pain at 12 months when compared to GnRH-a (VAS pain scale) (MD -2.0, 95% CI -20.2 to 16.2, 1 RCT, n = 40, very low-certainty evidence). Dysmenorrhoea: We are uncertain whether LNG-IUD improves dysmenorrhoea at six months when compared to GnRH-a (measured as a reduction in VAS pain score) (MD 1.70, 95%.CI -0.14 to 3.54, 1 RCT, n = 18, very low-certainty evidence). Adverse events: One study suggested that vasomotor symptoms were the most common adverse events reported with patients receiving GnRH-a, and irregular bleeding in those receiving LNG-IUD (n = 40, very low-certainty evidence) AUTHORS' CONCLUSIONS: Post-operative LNG-IUD is widely used to reduce endometriosis-related pain and to improve operative outcomes. This review demonstrates that there is no high-quality evidence to support this practice. This review highlights the need for further studies with large sample sizes to assess the effectiveness of post-operative adjuvant hormonal IUD on the core endometriosis outcomes (overall pain, most troublesome symptom, and quality of life).