PAS产前超声分级系统及子宫动脉超声参数在凶险性前置胎盘患者术前评估中的价值

Value of prenatal ultrasound grading system for PAS disorders and ultrasound parameters of uterine arteries in the preoperative evaluation of patients with dangerous placenta previa

摘要:

目的 评估胎盘植入性疾病（PAS）产前超声分级系统及子宫动脉超声参数在凶险性前置胎盘患者术前评估中的用价值。方法 选取2020年2月—2022年11月三亚市妇幼保健院收治的92例凶险性前置胎盘患者作为研究对象，根据PAS产前超声分级将患者分为≤ PAS-4组（1～4级）和>PAS-4 组（5、6级），其中≤ PAS-4组患者52例，> PAS-4组患者40例。比较两组患者一般临床资料、超声指标特征，采用多因素一般Logistic回归模型分析其在凶险性前置胎盘患者术前评估中的应用价值。结果 ≤ PAS-4组既往剖宫产次数少于> PAS-4组，完全性凶险型比例低于>PAS-4组，血流搏动指数（PI）、血液流动阻力（RI）高于> PAS-4组（P <0.05）。≤ PAS-4组子宫膀胱间高度血管化、胎盘后高度血管化、局部组织外生、胎盘陷窝支流血管、胎盘增厚、宫颈膨大、胎盘后间隙消失比例低于> PAS-4组（P <0.05）。多因素一般Logistic回归分析结果显示：PI高［O^R=0.961（95% CI：0.848，0.983）］、RI高［O^R=0.867（95% CI：0.839，0.923）］、既往剖宫产次数多［O^R=4.568（95% CI：2.012，7.609）］均是凶险性前置胎盘患者PAS产前超声分级>4级的影响因素（P <0.05）。联合预测凶险性前置胎盘患者PAS产前超声分级> 4级的曲线下面积最高，为0.929（95% CI：0.881，0.977），其次为既往剖宫产次数；RI敏感性最高，为0.910（95% CI：0.711，0.953），其次为PI；联合预测特异性最高，为0.956（95% CI：0.727，0.975），其次为既往剖宫产次数。结论 PI、RI、既往剖宫产次数指标在术前对凶险性前置胎盘PAS 4级以上患者有较好的预测价值，为术前制订手术方案提供了可靠的依据，可降低此类患者的手术并发症风险。

Abstract:

Objective To evaluate the value of the prenatal ultrasound grading system for placenta accreta spectrum (PAS) disorders and ultrasound parameters of uterine arteries in the preoperative evaluation of patients with dangerous placenta previa.Methods The 92 patients with dangerous placenta previa admitted to our hospital from February 2020 to November 2022 were selected, and they were divided into ≤ PAS-4 group (grade 1-4) and >PAS-4 group (grade 5-6) according to the prenatal ultrasound grading system for PAS disorders, where there were 52 and 40 cases in the ≤ PAS-4 group and the >PAS-4 group. The general clinical data and ultrasound parameters were compared between the two groups, and their values in the preoperative evaluation of patients with dangerous placenta previa were analyzed via the multivariable Logistic regression model.Results Compared with the > PAS-4 group, the number of previous cesarean sections and the proportion of complete dangerous placenta previa were lower, and the pulsatility index (PI) and the resistive index (RI) were higher in the ≤ PAS-4 group (P < 0.05). The proportions of hypervascularity of the uterine serosa-bladder wall interface, retroplacental hypervascularity, local tissue exogenesis of placenta, placental lacunae, thickened placenta, enlarged cervix, and disappearance of retroplacental space in the ≤ PAS-4 group were lower than those in the > PAS-4 groups (P < 0.05). The multivariable Logistic regression analysis demonstrated that high PI [O^R = 0.961 (95% CI: 0.848, .983) ], high RI [O^R = 0.867 (95% CI: 0.839 0.923) ], and multiple previous cesarean sections [O^R = .568 (95% CI: 2.012, 7.609) ] were the influencing factors for developing PAS disorders greater than grade 4 in patients with dangerous placenta previa (P < 0.05). The areas under the receiver operating characteristic curves of PI, RI, the number of previous cesarean sections and their combination for predicting PAS disorders greater than grade 4 in patients with dangerous placenta previa were 0.867 (95% CI: 0.784, 0.951), 0.820 (95% CI: 0.726, 0.915), 0.892 (95% CI: 0.827, 0.956), and 0.929 (95% CI: 0.881, 0.977), with the sensitivities being 0.863 (95% CI: 0.682, 0.904), 0.910 (95% CI: 0.711, 0.953), 0.858 (95% CI: 0.661, 0.896), and 0.843 (95 CI: 0.638, 0.900), and specificities being 0.829 (95% CI: 0.633, 0.857), 0.796 (95% CI: 0.593, 0.870), 0.875 (95% CI: 0.714, 0.921), and 0.956 (95% CI: 0.727, 0.975).Conclusion Patients with dangerous placenta previa with different grades of PAS disorders as assessed by prenatal ultrasound grading system show distinct involvement of parametrium and bladder and blood distribution at the uterine serosa-bladder wall interface, indicating the heterogeneity in the risks of bleeding and organ injury in the surgery. Besides, PI, RI and the number of previous cesarean sections exhibit a great predictive value for PAS disorders greater than grade 4 in patients with dangerous placenta previa, which provides solid evidence for preoperative surgical planning to reduce the risks of surgical complications in such patients.