Postoperative medical treatment of chronic pelvic pain related to severe endometriosis: levonorgestrel-releasing intrauterine system versus gonadotropin-releasing hormone analogue

OBJECTIVE: To compare efficacy of the levonorgestrel-releasing intrauterine system (LNG-IUS; Mirena) with depot GnRH analogue (GnRH-a; gosareline acetate; Zoladex) on endometriosis-related chronic pelvic pain (CPP) in patients with severe endometriosis during 12 months. DESIGN: Prospective, randomized, controlled study. SETTING: The reproductive endocrinology unit of a tertiary, research and education hospital. PATIENT(S): Forty women with severe endometriosis (revised The American Fertility Society [AFS] classification >40) and endometriosis-related CPP and control groups were enrolled in the study. INTERVENTION(S): The patients were treated with either LNG-IUS (n = 20) or GnRH-a (n = 20). The GnRH-a dose was repeated every 4 weeks for 24 weeks. MAIN OUTCOME MEASURE(S): Scores of CPP were evaluated using a visual analogue scale (VAS) and total endometriosis severity profile (TESP). RESULT(S): The TESP score decreased in the LNG-IUS group at first, third, and sixth month follow-up visits, whereas at the 12th month follow-up visit, the TESP scores were increased to values similar to pretreatment values. Although the VAS score had no significant alteration during the follow-up period in the LNG-IUS group, the GnRH-a group showed a significant decrease in the VAS score and TESP score at the end of 1 year. The LNG-IUS treatment showed a lower patient satisfaction. CONCLUSION(S): Both treatment modalities showed comparable effectiveness in the treatment of CPP-related endometriosis.