Three-dimensional volume rendering ultrasound for assessing placenta accreta spectrum severity and discriminating it from simple scar dehiscence.

BACKGROUND: 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. OBJECTIVE: 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. STUDY DESIGN: 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. RESULTS: 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). CONCLUSION: 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.

Geographic variation in management of patients with placenta accreta spectrum: An international survey of experts (GPASS).

OBJECTIVE: To describe global geographic variations in the diagnosis and management of placenta accreta spectrum (PAS). METHODS: An international cross-sectional study was conducted among PAS experts practicing at medical institutions in member states of the United Nations. Survey questions focused on diagnostic evaluation and management strategies for PAS. RESULTS: A total of 134 centers participated. Participating centers represented each of the United Nations' designated regions. Of those, 118 (88%) reported practicing in a medium-volume or high-volume center. First-trimester PAS screen was reported in 35 (26.1%) centers. Respondents consistently implement guideline-supported care practices, including utilization of ultrasound as the primary diagnostic modality (134, 100%) and implementation of multidisciplinary care teams (115, 85.8%). Less than 10% of respondents reported routinely managing PAS without hysterectomy; these centers were predominantly located in Europe and Africa. Antepartum management and availability of mental health support for PAS patients varied widely. CONCLUSION: Worldwide, there is a strong adherence to PAS care guidelines; however, regional variations do exist. Comparing variations in care to outcomes will provide insight into the clinically significant practice variability.

Lack of experience is a main cause of maternal death in placenta accreta spectrum patients.

INTRODUCTION: Placenta accreta spectrum (PAS) is a serious condition with a mortality as high as 7%. However, the factors associated with this type of death have not been adequately described, with an almost complete lack of publications analyzing the determining factors of death in this disease. The aim of our work is to describe the causes of death related to PAS and to analyze the associated diagnosis and treatment problems. MATERIAL AND METHODS: This is an inter-continental, multicenter, descriptive, retrospective study in low- and middle-income countries. Maternal deaths related to PAS between January 2015 and December 2020 were included. Crucial points in the management of PAS, including prenatal diagnosis and details of the surgical treatment and postoperative management, were evaluated. RESULTS: Eighty-two maternal deaths in 16 low- and middle-income countries, on three continents, were included. Almost all maternal deaths (81 cases, 98.8%) were preventable, with inexperience among surgeons being identified as the most relevant problem in the process that led to death among 87% (67 women) of the cases who had contact with health services. The main cause of death associated with PAS was hemorrhage (69 cases, 84.1%), and failures in the process leading to the diagnosis were detected among 64.6% of cases. Although the majority of cases received medical attention and 50 (60.9%) were treated at referral centers for severe obstetric disease, problems were identified during treatment in all cases. CONCLUSIONS: Lack of experience and inadequate surgical technique are the most frequent problems associated with maternal deaths in PAS. Continuous training of interdisciplinary teams is critical to modify this tendency.