Doppler US Nutrient Artery Waveform Change in Assessment of Non-pregnant Uterus Response to Oxytocin

Objective. Using Doppler Ultrasound to observe nutrient artery waveform change in uterine fibroids and focal adenomyosis before and after oxytocin, thereby assessing the response of non-pregnant uterus to oxytocin. Methods. 30 patients (mean age 39.77 ± 4.34 years) with uterine fibroids and 15 patients (mean age 36.27 ± 4.54 years) with focal adenomyosis were observed when ready for HIFU ablation. The nutrient artery waveform with Doppler US was observed for 30 minutes and compared before and after intravenous oxytocin (0.04u/min). Results. After oxytocin, abnormal waveforms were seen in 24 uterine fibroids patients(80%),as well as in 10 focal adenomyosis patients(66.7%), including monophasic-wedged, monophasic-domed, biphasic-wedged, or tropical fish. The difference was no statistically significant between uterine fibroids and focal adenomyosis (p>0.05). Waveform change could be categorized into two types, i.e., bizarre waveform which included persistent change (19/30,6/10) and alternative change (5/30,4/10), and normal waveform which included velocity change (6/30,5/15) and no change (0/30,0/15). There was no significant difference in the waveform change between subserosal fibroids and intramural fibroids (p>0.05). We did not observe any waveform change in uterine arcuate artery and bilateral uterine artery. Conclusions. Doppler US waveform change of uterine nutrient artery was useful in evaluating the response to oxytocin in non-pregnant uterus. Oxytocin could cause myometrium contraction, resulting in nutrient artery stenosis or spasm. There was no significant difference in the waveform change between subserosal fibroids and intramural fibroids, or between fibroids and focal adenomyosis, however, uterus responded quite individually to oxytocin.