[Effects of levonorgestrel intrauterine system on endometrial tissue after endometrial polyps resection by hysteroscopy].

Objective: To explore the changes of endometrial tissues after the insertion of levonorgestrel intrauterine system (LNG-IUS).

Methods: The endometrial tissues were harvested from 21 cases after endometrial polyps resection by hysteroscopy. And the patients received a 1-year follow-up. The immunohistochemical stains for estrogen receptor (ER), progesterone receptor (PR), Ki-67, bcl-2 and bax were used for semi-quantitative analyses. The changes of endometrial thickness were monitored and uterine weight was observed with a 3-year follow-up.

Results: The endometrial thickness and uterine weight declined continuously after the insertion of LNG-IUS. The endometrial thickness decreased from the preoperative level of (9.8 ± 1.2) mm to (3.5 ± 1.0) mm while the uterine weight dropped from the preoperative level of (98.8 ± 8.6) g to (66.6 ± 9.8) g. The expressions of ER, PR and Ki-67 were significantly lower than those of the para-polyps endometrial tissue (P < 0.05). The expressions of bcl-2 and bax were significantly higher than those of the para-polyps endometrial tissue (P < 0.05).

Conclusion: LNG-IUS may prevent the recurrence of uterine endometrial polyps through its inhibited expressions of ER, PR and Ki-67 and induced endometrial apoptosis.