THE HEMODYNAMIC-EFFECT OF GNRH AGONIST THERAPY ON UTERINE LEIOMYOMA VASCULARITY - A PROSPECTIVE-STUDY USING TRANSVAGINAL COLOR DOPPLER SONOGRAPHY

The objective of this study was to correlate, during 12 weeks of thera py with gonadotropin releasing hormone agonist (GnRH-a), the chronolog ical effect and the hemodynamic changes on the uterine artery and the leiomyometrial supplying vessels. Twenty-three premenopausal women wit h clinically diagnosed uterine leiomyomas received 3.75 mg of leuproli de acetate intramuscularly every 4 weeks for 12 weeks. Pretreatment va lues of serum estradiol, uterine and leiomyoma volumes and blood flow characteristics of the main uterine artery and leiomyoma supplying ves sels - resistance index (RI), pulsatility index (PI) and peak-systolic velocity, obtained by transvaginal color Doppler sonography - were co mpared with treatment values at 4, 8 and 12 weeks of leuprolide acetat e therapy.The first event in the chronological response to the GnRH-a therapy was a statistically significant increase in RI and PI values f or major leiomyoma vessels, observed at the end of the 4th week (p < 0 .05), which increased significantly after 8 and 12 weeks (p < 0.01 and p < 0.001, respectively). These findings were in direct correlation w ith a significant decrease of estradiol levels after 4, 8 and 12 weeks (p < 0.05, p < 0.001 and p < 0.001, respectively). The significant de crease of blood flow in the leiomyometrial vessels was followed by a s ignificant decrease of the main uterine artery blood flow after 8 week s and uterine and leiomyoma volumes by 42% and 55%, respectively, afte r 12 weeks of GnRH-a therapy. We concluded that a significant increase in leiomyometrial vessels TI and PI values, which was found 4 weeks a fter the first dose of GnRH-a, but without major leiomyoma volume decr ease, emphasizes that the first significant effect of GnRH therapy in the process of uterine and leiomyoma volume shrinkage is the reduction of leiomyometrial rather than uterine blood flow. This effect is foll owed by a considerable reduction of uterine vascularity and a signific ant decrease of uterine and leiomyoma volumes. If a decrease of blood loss during myomectomy is the main aim of GnRH-a therapy, we believe t hat 8 weeks would be an appropriate therapy duration.