NEW YORK (Reuters Health) – For women who have undergone laparoscopic surgery for severe endometriosis, ongoing chronic pelvic pain is relieved with use of the levonorgestrel-releasing intrauterine system (LNG-IUS; Mirena). However, the effect seems to fade after a year, according to a Turkish study.

Dr. Sadiman Kiykac Altinbas with the Etlik Zubeyde Hanim Women’s Health Teaching and Research Hospital in Ankara, Turkey, and colleagues report their findings in Fertility and Sterility online September 30. They note that following surgery for severe endometriosis, adjunctive hormonal medical treatment is given to prolong the symptom-free period and to prevent recurrence. However, side effects are common, so new options are needed.

The team tested the effects of the LNG-IUS in this setting. Forty affected women were randomized to receive the device or a depot GnRH analogue (GnRH-a; goserelin acetate; Zoladex). “The visual analogue scale (VAS) and total endometriosis severity profile (TESP) were used to evaluate the efficacy of both treatments in the management of pelvic pain during a period of 12 months,” according to the report.

Mean pretreatment VAS scores were 42.5 in the LNG-IUS group and 64.1 in the GnRH-a group, a non-significant difference. Scores dropped significantly for 6 months for both groups after starting treatment, but by 1 year the score had returned to baseline in the LNG-IUS group; the decrease in pain score remained significant in the GnRH-a group.

The TESP scores showed a similar pattern.

Irregular bleeding (65%) and lower abdominal pain (40%) were causes of dissatisfaction among women given the LNG-IUS. Among those given GnRH-a, 50% experienced vasomotor symptoms and 30% were amenorrheic, but these side effects did not reduce patient satisfaction.

“The LNG-IUS represents a new option for the treatment of CPP. However, patient compliance and satisfaction can decrease because of side effects,” the authors conclude.

They add, “Although the data from the published studies, including the presented study, show improvement of symptoms during LNG-IUS use comparable to the use of GnRH-a, the long-term results are still debatable.”

Fertil Steril 2010.