Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.
Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA, USA.
Ultrasound Med Biol. 2023 Dec;49(12):2557-2564. doi: 10.1016/j.ultrasmedbio.2023.08.021. Epub 2023 Sep 24.
During early human pregnancy, placental trophoblasts remodel spiral arteries into distensible low-resistance vessels to promote placental perfusion. We have established a model of impaired spiral artery remodeling (SAR) by elevating estradiol levels in the first trimester of baboon pregnancy. In the present study, B-flow/spatiotemporal image correlation (STIC) M-mode ultrasonography, a non-Doppler technology for sharp rendering of vessel dimensions, was used to determine whether spiral artery distensibility was altered in SAR-suppressed baboons. Contrast-enhanced ultrasound/microbubble imaging was also performed to determine whether it detected changes in placenta intervillous space perfusion in SAR-suppressed baboons.
The two imaging procedures were performed in the first trimester in baboons not treated or treated with estradiol to suppress SAR.
Spiral artery distensibility, that is, luminal diameter at systole minus diameter at diastole, and volume flow as quantified by B-flow/STIC M-mode were 26% (p = 0.03) and 55% (p = 0.059) lower, respectively, in SAR-suppressed baboons. However, placental intervillous space flow rate and video intensity plateau levels reflecting blood perfusion, quantified by contrast-enhanced ultrasound/microbubble imaging, were unaltered in SAR-suppressed baboons.
The results indicate that B-flow/STIC M-mode ultrasonography provides a non-invasive method to detect reduced distensibility and, thus, function of spiral arteries across the cardiac cycle in the first trimester in a primate model of impaired SAR. This study represents a first step in determining whether B-flow/STIC M-mode detects a similar defect in SAR early in adverse human pregnancy. This would provide an avenue to develop therapeutic modalities to prevent the devastating consequences of impaired SAR.
在人类妊娠早期，胎盘滋养层细胞重塑螺旋动脉为可扩张的低阻力血管，以促进胎盘灌注。我们通过提高狒狒妊娠早期的雌二醇水平，建立了螺旋动脉重塑不良（SAR）模型。在本研究中，采用 B 型血流/时空图像相关（STIC）M 型超声技术，一种用于清晰显示血管尺寸的非多普勒技术，来确定 SAR 抑制的狒狒中螺旋动脉的扩张性是否发生改变。还进行了对比增强超声/微泡成像，以确定它是否检测到 SAR 抑制的狒狒胎盘绒毛间隙灌注的变化。
在未治疗或用雌二醇抑制 SAR 的狒狒中，在妊娠早期进行这两种成像程序。
通过 B 型血流/STIC M 型测量，螺旋动脉的可扩张性（即收缩期管腔直径减去舒张期直径）和体积流量分别降低了 26%（p=0.03）和 55%（p=0.059）。然而，通过对比增强超声/微泡成像定量的胎盘绒毛间隙血流率和反映血液灌注的视频强度平台水平在 SAR 抑制的狒狒中没有改变。
结果表明，B 型血流/STIC M 型超声提供了一种非侵入性方法，可在 SAR 受损的灵长类动物模型中检测到妊娠早期整个心动周期中螺旋动脉的扩张性降低和功能障碍。这项研究代表了确定 B 型血流/STIC M 型是否在 SAR 早期的不良妊娠中检测到类似缺陷的第一步。这将为开发治疗方法以预防 SAR 受损的破坏性后果提供途径。
