A COMPARATIVE-STUDY OF AN ESTRADIOL-RELEASING VAGINAL RING VERSUS TIBOLONE IN POSTMENOPAUSAL WOMEN - A TRANSVAGINAL COLOR DOPPLER STUDY

Objective: To evaluate endometrial blood flow characteristics in respo nse to estrogen replacement therapy (ERT) and tibolone in postmenopaus al women and to correlate the resistance index (RI) with plasma estrad iol levels. Materials and methods: Transvaginal color Doppler ultrasou nd examinations were performed in 72 asymptomatic, postmenopausal wome n who demonstrated endometrial thickness less than or equal to 5 mm. T hirty-six women receiving tibolone and 36 patients receiving ERT by a vaginal ring comprised the study groups. Results: All postmenopausal w omen treated with tibolone or ERT showed continuous forward end-diasto lic flow. The lowest RI was obtained in women with the vaginal ring in serted. The plasma concentrations of estradiol were found to be signif icantly higher in the vaginal ring group than those of tibolone. Concl usions: The data observed suggest that ERT and tibolone modify normal postmenopausal endometrial perfusion. Tibolone had a weaker estrogenic effect on endometrial blood flow resistance, and vaginal ring treatme nt enhanced endometrial blood perfusion through vasodilatation. (C) 19 97 Elsevier Science Ireland Ltd.