Levonorgestrel-releasing intrauterine system and combined oral contraceptives as conservative treatments for recurrent ovarian endometriosis: a comparative clinical study

Abstract

To evaluate and compare the efficiency and safety of levonorgestrel-releasing intrauterine system (LNG-IUS) and combined oral contraceptives (COC) in the treatment of recurrent ovarian endometriosis after conservative surgery or conservative surgery plus medical therapy. A total of 48 patients with recurrent ovarian endometriosis underwent randomization. The regimens of LNG-IUS (n = 24) and COC (n = 24) were offered. The volume of ovarian endometriotic cysts was recorded before treatment and at 6, 12, 18 and 24 months. The volume of ovarian endometriotic cysts, pain score of visual analogue scale (VAS), menstrual pattern, body weight, serum CA125 and serum lipids were compared to the pretreatment level within each treatment group, as well as between two treatment groups during the same period. (1) At 18 months after LNG-IUS, the cysts in 2 subjects entirely disappeared. At 24 months, 18 patients had a disappearance of cysts. The overall size reduction was statistically significant (9.2 ± 3.0) vs (0.9 ± 1.5) cm(3) (P < 0.01). In the COC group, 12 subjects had a complete resolution of cysts at 24 months. The overall size reduction was statistically significant (9.4 ± 2.2) vs (2.9 ± 3.1) cm(3) (P < 0.01). At 18 & 24 months, the cyst size reduction was significantly larger in the LNG-INS group than the COC group (2.4 ± 1.5) vs (4.7 ± 2.6) cm(3) (P < 0.01) and (0.9 ± 1.5) vs (2.9 ± 3.1) cm(3) (P < 0.05); (2) There was a significant improvement of dysmenorrhea, chronic pelvic pain and dyspareunia at 6- & 12-month follow-up in both groups; (3) serum CA125 decreased at 6 & 12 months in both groups with statistical significance. It decreased more sharply in the LNG-IUS group and remained at low levels beyond 12 months; (4) within 6 months of LNS-IUS, irregular bleeding and spotting were the major side effects. Beyond that period the symptoms were significantly relieved. Weight gain and dyslipidemia were the major side effects of COC. For patients with recurrent ovarian endometriosis after conservative surgery or conservative surgery plus medical therapy, LNG-IUS and COC may be used to control and reduce endometriotic cysts, relieve pain and reduce the level of CA125. LNG-IUS has the advantages of a greater convenience and minor systemic side effects.