背景:产前超声区分胎盘植入谱(PAS)和瘢痕裂开与潜在的非贴壁胎盘在产前和术中都具有挑战性,这通常会导致过度治疗。此外,在PAS中,很难准确预测手术难度和发病率,这妨碍了适当的多学科计划。现代超声系统中先进的三维体绘制和对比增强技术的出现提供了全面的产前评估,揭示了传统2D成像中无法识别的细节。
目的:评估三维容积再现超声技术在确定PAS严重程度以及区分PAS和潜在非贴壁胎盘瘢痕裂开方面的应用。
方法:前瞻性,队列研究于2022年7月至2023年7月在Soetomo博士学术总医院的胎儿医学部门进行,泗水,印度尼西亚。所有因怀疑PAS而转诊的前低位胎盘或前置胎盘的孕妇均同意并使用标准化的二维(2D)和多普勒超声成像进行筛查。从充满膀胱的子宫矢状部分获得额外的3D体积。通过将感兴趣的区域旋转为垂直于子宫膀胱界面来分析这些。主要结果是PAS病例的临床和组织学严重程度,以及下方非粘连胎盘裂开的正确诊断。确定超声与临床结果之间的关联强度。使用多变量逻辑回归分析和准确性的诊断测试来分析数据。
结果:共有70例患者(56例PAS患者和14例瘢痕裂开患者)纳入分析。所有2D和3D体征的多变量逻辑回归显示,在2D多普勒超声(p=0.027)上,透明区的3D丢失(p<0.001)和桥接血管的存在是区分瘢痕裂开和PAS的出色预测因子。清晰区的3D损失显示出较高的诊断准确性,曲线下面积(AUC)为0.911(95%CI0.819-1.002),敏感性为89.3%(95%CI78.1-95.97%),特异性为92.9%(95%CI66.1-99.8%)。2D多普勒上桥接血管的存在显示AUC为0.848(95%CI0.714-0.982),灵敏度为91.1%(95%CI80.4-97.0%),特异性为78.6%(95%CI49.2-95.3%)。PAS组中的亚组分析显示,膀胱腔间隙闭塞的3D膀胱浆膜的存在与膀胱腔粘连有关(p<0.001)。
结论:3D容积再现超声是有效区分具有潜在非贴壁胎盘的瘢痕裂开和PAS的有希望的工具。它还显示了在PAS病例中预测膀胱受累的临床严重程度的潜力。
Prenatal ultrasound discrimination between placenta accreta spectrum and scar dehiscence with underlying nonadherent placenta is challenging both prenatally and intraoperatively, which often leads to overtreatment. In addition, accurate prenatal prediction of surgical difficulty and morbidity in placenta accreta spectrum is difficult, which precludes appropriate multidisciplinary planning. The advent of advanced 3-dimensional volume rendering and contrast enhancement techniques in modern ultrasound systems provides a comprehensive prenatal assessment, revealing details that are not discernible in traditional 2-dimensional imaging.
This study aimed to evaluate the use of 3-dimensional volume rendering ultrasound techniques in determining the severity of placenta accreta spectrum and distinguishing between placenta accreta spectrum and scar dehiscence with underlying nonadherent placenta.
A prospective, cohort study was conducted between July 2022 and July 2023 in the fetal medicine unit of Dr Soetomo Academic General Hospital, Surabaya, Indonesia. All pregnant individuals with anterior low-lying placenta or placenta previa with a previous caesarean section who were referred with suspicion of placenta accreta spectrum were consented and screened using the standardised 2-dimensional and Doppler ultrasound imaging. Additional 3-dimensional volumes were obtained from the sagittal section of the uterus with a filled urinary bladder. These were analyzed by rotating the region of interest to be perpendicular to the uterovesical interface. The primary outcomes were the clinical and histologic severity in the cases of placenta accreta spectrum and correct diagnosis of dehiscence with nonadherent placenta underneath. The strength of association between ultrasound and clinical outcomes was determined. Multivariate logistic regression analyses and diagnostic testing of accuracy were used to analyze the data.
A total of 70 patients (56 with placenta accreta spectrum and 14 with scar dehiscence) were included in the analysis. Multivariate logistic regression of all 2-dimensional and 3-dimensional signs revealed the 3-dimensional loss of clear zone (P<.001) and the presence of bridging vessels on 2-dimensional Doppler ultrasound (P=.027) as excellent predictors in differentiating scar dehiscence and placenta accreta spectrum. The 3-dimensional loss of clear zone demonstrated a high diagnostic accuracy with an area under the curve of 0.911 (95% confidence interval, 0.819-1.002), with a sensitivity of 89.3% (95% confidence interval, 78.1-95.97%) and specificity of 92.9% (95% confidence interval, 66.1-99.8%). The presence of bridging vessels on 2-dimensional Doppler demonstrated an area under the curve of 0.848 (95% confidence interval, 0.714-0.982) with a sensitivity of 91.1% (95% confidence interval, 80.4-97.0%) and specificity of 78.6% (95% confidence interval, 49.2-95.3%). A subgroup analysis among the placenta accreta spectrum group revealed that the presence of a 3-dimensional disrupted bladder serosa with obliteration of the vesicouterine space was associated with vesicouterine adherence (P<.001).
Three-dimensional volume rendering ultrasound is a promising tool for effective discrimination between scar dehiscence with underlying nonadherent placenta and placenta accreta spectrum. It also shows potential in predicting the clinical severity with urinary bladder involvement in cases of placenta accreta spectrum.