A novel MRI-based diagnostic model for predicting placenta accreta spectrum.

Objective To develop and evaluate a diagnostic model based on MRI signs for predicting placenta accreta spectrum. Materials and Methods A total of 155 pregnant women were included in this study, randomly divided into 104 cases in the training set and 51 cases in the validation set. There were 93 Non-PAS cases, and 62 cases in the PAS group. The training set included 62 Non-PAS cases and 42 PAS cases. Clinical factors and MRI signs were collected for univariate analysis. Then, binary logistic regression analysis was used to develop independent diagnostic models with clinical relevant risk factors or MRI signs, as well as those combining clinical risk factors and MRI signs. The ROC curve analysis was used to evaluate the diagnostic performance of each diagnostic model. Finally, the validation was performed with the validation set. Results In the training set, four clinical factors (gestity, parity, uterine surgery history, placental position) and 11 MRI features (T2-dark bands, placental bulge, T2 hypointense interface loss, myometrial thinning, bladder wall interruption, focal exophytic mass, abnormal placental bed vascularization, placental heterogeneity, asymmetric placental thickening/shape, placental ischemic infarction, abnormal intraplacental vascularity) were considered as risk factors for PAS. The AUC of the clinical diagnostic model, MRI diagnostic model, and clinical + MRI model of PAS were 0.779, 0.854, and 0.874, respectively. In the validation set, the AUC of the clinical diagnostic model, MRI diagnostic model, and clinical + MRI model of PAS were 0.655, 0.728, and 0.735, respectively. Conclusion Diagnosis model based on MRI features in this study can well predict placenta accreta spectrum.

Application of Uterine Artery Embolization in Patients With Placenta Accreta Spectrum After Abdominal Aortic Balloon Occlusion.

OBJECTIVE: To evaluate the application of different uterine artery embolization procedures under balloon occlusion of the abdominal aorta in patients with Placenta Accreta Spectrum (PAS) undergoing cesarean section. MATERIALS AND METHODS: A retrospective analysis was performed on clinical data from 72 patients who underwent uterine artery embolization for hemostasis during cesarean section with PAS. The patients were divided into two groups according to the embolization method used during surgery: group A (n = 43) underwent uterine artery embolization by withdrawing the balloon and inserting a Cobra catheter into the uterine artery for embolization, while group B (n = 29) underwent uterine artery embolization with a Cobra catheter inserted via contralateral puncture of the femoral artery and balloon occlusion. General information, surgical data, and postoperative recovery were compared between the 2 groups. RESULTS: The bleeding and transfusion volumes were lower in group B than in group A and the differences between the 2 groups were statistically significant. There were no significant differences in surgical duration, number of embolized vessels, length of hospital stay, postoperative complications, or menstrual recovery between the 2 groups. CONCLUSION: For patients with PAS undergoing cesarean section, uterine artery embolization for hemostasis is preferably performed by inserting a Cobra catheter via contralateral puncture of the femoral artery under abdominal aortic balloon occlusion.

Placental lakes vs lacunae: spot the differences.

Sonographic sonolucencies are anechoic areas surrounded by tissue of normal echogenicity, commonly found in the placental parenchyma during the second and third trimesters of pregnancy. The ultrasound appearance of lakes and lacunae derives from the low echogenicity of villous-free areas within the placental parenchyma, filled with maternal blood of varying velocities. In normal placentation, lakes usually start appearing as soon as maternal blood begins to flow freely within the intervillous space at the end of the first trimester, whereas, in accreta placentation, lacunae develop progressively during the second trimester. Larger lakes are found mainly in areas of lower villous density under the fetal plate or in the marginal areas, but can also be found in the center of a lobule above the entry of a spiral artery. Lakes of variable size, position and shape are of no clinical significance, except if they transform into echogenic cystic lesions, which have been associated with poor fetal growth and placental malperfusion. Lacunae are formed by the distortion of one or more placental lobules developing inside a uterine scar, resulting from high-volume, high-velocity flows from the radial/arcuate arteries, and are associated with a high probability of placenta accreta spectrum at birth. They often present with ultrasound signs of uterine remodeling following scarring. Lakes and lacunae can coexist within the same placenta and both will change in size and shape as pregnancy advances. Better understanding of the etiopathology of placental sonolucent spaces and associated morphological changes is necessary to identify patients at risk of subsequent complications during pregnancy and/or at delivery. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Transabdominal and transvaginal ultrasound findings help to guide the clinical management of placenta accreta spectrum cases.

INTRODUCTION: The clinical management of placenta accreta spectrum (PAS) depends on placental topography and vascular involvement. Our aim was to determine whether transabdominal and transvaginal ultrasound signs can predict PAS management. MATERIAL AND METHODS: We conducted a retrospective cohort study of consecutive prenatally suspected PAS cases in a single tertiary-care PAS center between January 2021 and July 2022. When PAS was confirmed during surgery, abdominal and transvaginal ultrasound scans were analyzed in relation to PAS management. The preferred surgical approach of PAS was one-step conservative surgery (OSCS). Massive blood loss and PAS topography in the lower bladder trigone necessitated cesarean hysterectomy. Transvaginal ultrasound-diagnosed intracervical hypervascularity was split into three categories based on their quantity. Anatomically, the internal cervical os is located at the level of the bladder trigone and was used as landmark for upper and lower bladder trigone PAS. RESULTS: Ninety-one women underwent OSCS and 35 women underwent cesarean hysterectomy (total 126 women with PAS). Abdominal and transvaginal ultrasound features differed significantly between women that underwent OSCS and cesarean hysterectomy: decreased myometrial thickness (<1 mm), 82.4% vs. 100%, p = 0.006; placental bulge, 51.6% vs. 94.3%, p < 0.001; bladder wall interruption, 62.6% vs. 97.1%, p < 0.001; abnormal placental lacunae, 75.8% vs. 100%, p < 0.001; hypervascularity (large lacunae feeding vessels, 57.8% vs. 94.6%, p < 0.001; parametrial hypervascularity, 15.4% vs. 60%, p < 0.001; the rail sign, 6.6% vs. 28.6%, p = 0.003; three-dimensional Doppler intra-placental hypervascularity, 81.3% vs. 100%, p < 0.001; intracervical hypervascularity 60.4% vs. 94.3%, p < 0.001); and cervical length 2.5 ± 0.94 vs. 2.2 ± 0.73, p = 0.038. Other ultrasound signs were not significantly different. The results of multivariable logistic regression showed placental bulge (odds ratio [OR] 9.3; 95% CI 1.9-44.3; p = 0.005), parametrial hypervascularity (OR 4.1; 95% CI 1.541-11.085; p = 0.005), and intracervical hypervascularity (OR 9.2; 95% CI 1.905-44.056; p = 0.006) were weak predictors of OSCS. Intracervical hypervascularity Grade 1 (vascularity <50% of cervical tissue) was more present in OSCS than higher gradings two and three (91% vs. 27.6% vs. 14.3%; p < 0.001). CONCLUSIONS: Cesarean hysterectomy is associated with the PAS signs of placental bulge and Grade 2 and 3 intracervical hypervascularity. OSCS is associated with intracervical hypervascularity Grade 1 on transvaginal ultrasound. Prospective validation is required to formulate predictors for PAS management.

[Prenatal diagnosis of placenta acretta by ultrasound and its histopathological association]. / Diagnóstico prenatal de acretismo placentario por ultrasonido y su asociación histopatológica.

Background: Anomalous adhesions of the placenta, known as placenta accreta and its variants, are the cause of obstetric hemorrhages that put the pregnant woman at risk. Accretism is strongly associated with a history of uterine surgery (cesarean section, myomectomy, curettage), as well as ultrasonographic signs, such as the presence and size of placental lacunae, loss of the placenta/bladder interface, location on the anterior face of the placenta, and presence of Doppler flow; these markers can be assessed by prenatal ultrasound. Objective: To analyze the association of prenatal diagnosis of placenta accreta by ultrasound with the histopathological result using the Tovbin index. Material and methods: Observational, cross-sectional and analytical study. 63 patients who had placenta accreta data by ultrasound measured with the Tovbin index and by means of the histopathological result obtained from the platform of the Mexican Institute for Social Security (IMSS) were included. The association between the two studies with the presence of placenta accreta was analyzed. Results: 63 patients were analyzed; the Tovbin index was positive in 89% of the patients with a diagnosis of placenta accreta confirmed by histopathology. Both the Tovbin index and the histopathology report showed a statistically significant association with a p value of 0.04 for the diagnosis of placenta accreta. Conclusion: The Tovbin index as an ultrasonographic prenatal diagnosis of placenta accreta has a statistically significant association with histopathology diagnosis.

Introducción: las adherencias anómalas de la placenta, conocidas como acretismo, y sus variantes son causa de hemorragias obstétricas que ponen en riesgo a la gestante. El acretismo se asocia firmemente con antecedentes de cirugías uterinas (cesárea, miomectomía, legrados), así como con signos ultrasonográficos como presencia y tamaño de lagunas placentarias, pérdida de la interfaz placenta/vejiga, localización en cara anterior de la placenta y presencia de flujo Doppler; estos marcadores pueden ser valorados mediante ecografía prenatal. Objetivo: analizar la asociación de diagnóstico prenatal de acretismo placentario por ultrasonido con el resultado histopatológico utilizando el Índice de Tovbin. Material y métodos: estudio observacional, transversal y analítico. Se incluyeron 63 pacientes que tenían datos de acretismo placentario por ultrasonido medido con el Índice de Tovbin y mediante el resultado histopatológico obtenido de la plataforma del Instituto Mexicano del Seguro Social. Se analizó la asociación de ambos estudios con la presencia de acretismo placentario. Resultados: se analizaron 63 pacientes; el Índice de Tovbin fue positivo en un 89% de las pacientes con diagnóstico de acretismo placentario confirmado por histopatología. Tanto el Índice de Tovbin como el reporte de histopatología mostraron una asociación estadísticamente significativa con un valor de p de 0.04 para el diagnóstico de acretismo placentario. Conclusión: el Índice de Tovbin como diagnóstico prenatal ultrasonográfico de acretismo placentario tiene asociación estadísticamente significativa con el diagnóstico de histopatología.

Prediction of placenta accreta spectrum in patients with placenta previa using a clinical, US and MRI combined model: A retrospective study with external validation.

PURPOSE: To build and validate a predictive model of placental accreta spectrum (PAS) in patients with placenta previa (PP) combining clinical risk factors (CRF) with US and MRI signs. METHOD: Our retrospective study included patients with PP from two institutions. All patients underwent US and MRI examinations for suspicion of PAS. CRF consisting of maternal age, cesarean section number, smoking and hypertension were retrieved. US and MRI signs suggestive of PAS were evaluated. Logistic regression analysis was performed to identify CRF and/or US and MRI signs associated with PAS considering histology as the reference standard. A nomogram was created using significant CRF and imaging signs at multivariate analysis, and its diagnostic accuracy was measured using the area under the binomial ROC curve (AUC), and the cut-off point was determined by Youden's J statistic. RESULTS: A total of 171 patients were enrolled from two institutions. Independent predictors of PAS included in the nomogram were: 1) smoking and number of previous CS among CRF; 2) loss of the retroplacental clear space at US; 3) intraplacental dark bands, focal interruption of the myometrial border and placental bulging at MRI. A PAS-prediction nomogram was built including these parameters and an optimal cut-off of 14.5 points was identified, showing the highest sensitivity (91%) and specificity (88%) with an AUC value of 0.95 (AUC of 0.80 in the external validation cohort). CONCLUSION: A nomogram-based model combining CRF with US and MRI signs might help to predict PAS in PP patients, with MRI contributing more than US as imaging evaluation.

Termination of a second-trimester pregnancy with placenta accreta spectrum disorder.

Background: The termination of pregnancy in patients with placenta accreta spectrum disorder (PASD) during the second trimester remains uncertain. In addition, interventional radiology techniques, such as arterial embolization and balloon placement, are potential options. We evaluated the outcomes of pregnancy termination in patients with PASD during the second trimester and the effectiveness of preoperative interventional radiology techniques.Methods: This retrospective study analyzed 48 PASD patients who underwent pregnancy termination during the second trimester between January 2016 and May 2021.Results: Of the 48 patients, 20 (41.67%) underwent transvaginal termination, whereas 28 (58.33%) underwent cesarean section. Notably, no significant differences were observed in success rates between the transvaginal termination and cesarean section groups (80.00% vs. 92.86%, P = 0.38). Furthermore, no statistically significant differences were observed in the success rates (94.12% vs 90.32%, P = 1.00) and blood loss (512.35 ± 727.00 ml vs 804.00 ± 838.98 ml, P = 0.23) between the artery embolization and non-embolization groups. In the vaginal termination group, statistically significant differences were observed in gestational weeks (16.70 ± 3.12 vs 22.67 ± 3.63, P < 0.01) and blood loss (165.00 ± 274.43 ml vs 483.64 ± 333.53 ml, P = 0.04) between the (artery embolization and non-embolization) subgroups. Conversely, in the cesarean section group, no significant differences were observed in gestational weeks (23.59 ± 3.14 vs 23.20 ± 4.37, P = 0.79) and blood loss (811.11 ± 879.55 ml vs 989.47 ± 986.52 ml, P = 0.76) between the subgroups.Conclusions: Further studies are needed to evaluate the efficacy of vaginal termination in PASD patients during the second trimester. Regarding cesarean termination, arterial embolization did not demonstrate increased effectiveness.

Treatment of infected placenta accreta in the uterine horn by transabdominal temporary occlusion of internal iliac arteries: A case report and literature review.

RATIONALE: This case report aims to describe the treatment of infected placenta accreta in the uterine horn by transabdominal temporary occlusion of internal iliac arteries. PATIENT CONCERNS: A 29-year-old female patient had a history of retained placenta for 28 days after labor induction in the second trimester of pregnancy because of fetal malformation. DIAGNOSES: Placenta accreta in the uterine horn was diagnosed by 3-dimensional ultrasound and magnetic resonance imaging, and the diagnosis was confirmed during the operation. INTERVENTIONS: Laparotomy was performed to remove the placenta and repair the uterine defect after temporary occlusion of both internal iliac arteries. OUTCOMES: Body temperature and inflammatory markers were elevated at admission but returned to normal on the second day after surgery. Normal menstruation resumed approximately 1 month postoperatively. Ultrasound examination showed that the shape of the uterine cavity was normal. No postoperative complications were observed. LESSONS: Temporary occlusion of the internal iliac artery can help effectively manage infected placenta accreta in the uterine horn.

[Outcome analysis of pregnancy termination and expectant treatment in pregnant women with suspected invasive placenta accreta spectrum disorders in the second trimester].

Objective: To investigate the maternal and fetal outcomes of expectant treatment and early termination of pregnancy in pregnant women with suspected invasive placenta accreta spectrum disorders (PAS) in the second trimester. Methods: A retrospective cohort study was performed on 51 pregnant women with suspected invasive PAS (ultrasound score ≥10) evaluated by ultrasound with gestational age <26 weeks and confirmed as invasive PAS by intraoperative findings or postoperative pathology in Peking University Third Hospital from January 2015 to January 2022. According to the informed choice of pregnant women and their families, they were divided into expectant treatment group (37 cases) and mid-term termination group (14 cases). The general clinical data and outcome indexes of the two groups were analyzed by χ2 test, Mann-Whitney U rank sum test, logistic regression and linear regression. Results: (1) General clinical data: among 51 pregnant women who were assessed as suspected invasive PAS by ultrasonography in the second trimester, invasive PAS was finally diagnosed by intraoperative findings and postoperative pathology, among which 46 cases (90%) were placenta percreta and 5 cases (10%) were placenta increta. (2) Outcome indicators: univariate analysis showed that there were no statistically significant differences in the intraoperative blood loss (median: 2 200 vs 2 150 ml), the proportion of blood loss >1 500 ml [73% (27/37) vs 9/14], the hysterectomy rate [62% (23/37) vs 8/14], the rate of intensive care unit (ICU) admission [78% (29/37) vs 9/14] between the expectant treatment group and the mid-term termination group (all P>0.05). Multivariate analysis showed that the rate of intraoperative blood loss >1 500 ml (aOR=0.481, 95%CI: 0.017-13.958; P=0.670), hysterectomy (aOR=0.264, 95%CI: 0.011-6.569, P=0.417) and ICU admission (aOR=1.327, 95%CI: 0.048-36.882, P=0.867) between the two groups showed no statistical differences. (3) Outcome analysis: all 37 cases in the expectant treatment group had live births and no early neonatal death. Five pregnant women (14%, 5/37) in the expectant treatment group underwent emergency cesarean section in the course of expectant treatment. In the mid-term termination group, all pregnancies were terminated by operation, including 9 cases of hysterectomy and 5 cases of placental hysterectomy. There was 1 fetal survival (gestational age of termination: 27+4 weeks) and 13 fetal death in the mid-term termination group. Conclusions: Pregnant women who are diagnosed as suspected invasive PAS, especially those with placenta percreta, have the risk of uterine rupture and emergency surgery in the course of expectant treatment. However, early termination of pregnancy does not reduce the risk of intraoperative blood loss and hysterectomy.

Placenta Accreta Spectrum.

Placenta accreta spectrum (PAS) is one of the most dangerous conditions in pregnancy and is increasing in frequency. The risk of life-threatening bleeding is present throughout pregnancy but is particularly high at the time of delivery. Although the exact cause is unknown, the result is clear: Severe PAS distorts the uterus and surrounding anatomy and transforms the pelvis into an extremely high-flow vascular state. Screening for risk factors and assessing placental location by antenatal ultrasonography are essential for timely diagnosis. Further evaluation and confirmation of PAS are best performed in referral centers with expertise in antenatal imaging and surgical management of PAS. In the United States, cesarean hysterectomy with the placenta left in situ after delivery of the fetus is the most common treatment for PAS, but even in experienced referral centers, this treatment is often morbid, resulting in prolonged surgery, intraoperative injury to the urinary tract, blood transfusion, and admission to the intensive care unit. Postsurgical complications include high rates of posttraumatic stress disorder, pelvic pain, decreased quality of life, and depression. Team-based, patient-centered, evidence-based care from diagnosis to full recovery is needed to optimally manage this potentially deadly disorder. In a field that has relied mainly on expert opinion, more research is needed to explore alternative treatments and adjunctive surgical approaches to reduce blood loss and postoperative complications.

Espectro do acretismo placentário: recomendações atualizadas da perspectiva do profissional de imagem pré-natal / Placenta accreta spectrum disorders: current recommendations from the perspective of antenatal imaging

O parto cesáreo (PC) é o procedimento cirúrgico mais comumente realizado nos Estados Unidos (mais de 1 milhão de cirurgias por ano) e um dos procedimentos mais realizados em todo o mundo.(1) Embora o PC seja um procedimento potencialmente salvador de vidas, quando corretamente indicado, sua frequência aumentou constantemente nas últimas décadas (atualmente 21,1% globalmente, variando de 5%, na África Subsaariana, a 42,8%, na América Latina e no Caribe). Além disso, estudos demonstram tendência continuada de aumento (projeção para 2030: 28,5% globalmente, variando de 7,1%, na África Subsaariana, a 63,4%, no leste da Ásia).(2) República Dominicana, Brasil, Chipre, Egito e Turquia são os líderes mundiais, com taxas de PC variando de 58,1% a 50,8%, respectivamente, o que aponta para uma tendência preocupante de medicalização do parto e indicação excessiva do PC.(2) Outros procedimentos cirúrgicos como dilatação, curetagem, miomectomia e histeroscopia cirúrgica são menos frequentes que o PC. Ainda assim, devido à tendência de maior idade materna, o número de gestantes previamente submetidas a esses procedimentos também tende a aumentar. Esses dados apontam para um número crescente de gestações em úteros manipulados cirurgicamente Gestantes com cicatrizes uterinas prévias correm risco de aumento da morbimortalidade. Complicações como placenta prévia, rotura uterina espontânea, deiscência uterina (com ou sem intrusão placentária), gestação em cicatriz de cesariana (GCC) e distúrbios do espectro do acretismo placentário (EAP) estão associadas a sangramento uterino potencialmente fatal, lesões extrauterinas e parto pré-termo

Placenta accreta spectrum into the parametrium, morbidity differences between upper and lower location.

OBJECTIVE: To demonstrate the surgical and morbidity differences between upper and lower parametrial placenta invasion (PPI). MATERIALS AND METHODS: Forty patients with placenta accreta spectrum (PAS) into the parametrium underwent surgery between 2015 and 2020. Based on the peritoneal reflection, the study compared two types of parametrial placental invasion (PPI), upper or lower. Surgical approach to PAS follows a conservative-resective method. Before delivery, surgical staging by pelvic fascia dissection established a final diagnosis of placental invasion. In upper PPI cases, the team attempted to repair the uterus after resecting all invaded tissues or performing a hysterectomy. In cases of lower PPI, experts performed a hysterectomy in all cases. The team only used proximal vascular (aortic occlusion) control in cases of lower PPI. Surgical dissection for lower PPI started finding the ureter in the pararectal space, ligating all the tissues (placenta and newly formed vessels) to create a tunnel to release the ureter from the placenta and placenta suppletory vessels. Overall, at least three pieces of the invaded area were sent for histological analysis. RESULTS: Forty patients with PPI were included, 13 in the upper parametrium and 27 in the lower parametrium. MRI indicated PPI in 33/40 patients; in three, the diagnosis was presumed by ultrasound or medical background. The intrasurgical staging categorizes 13 cases of PPI performed and finds diagnosis in seven undetected cases. The expertise team completed a total hysterectomy in 2/13 upper PPI cases and all lower PPI cases (27/27). Hysterectomies in the upper PPI group were performed by extensive damage of the lateral uterine wall or with a tube compromise. Ureteral injury ensued in six cases, corresponding to cases without catheterization or incomplete ureteral identification. All aortic vascular proximal control (aortic balloon, internal aortic compression, or aortic loop) was efficient for controlling bleeding; in contrast, ligature of the internal iliac artery resulted in a useless procedure, resulting in uncontrollable bleeding and maternal death (2/27). All patients had antecedents of placental removal, abortion, curettage after a cesarean section, or repeated D&C. CONCLUSIONS: Lower PAS parametrial involvement is uncommon but associated with elevated maternal morbidity. Upper and lower PPI has different surgical risks and technical approaches; consequently, an accurate diagnosis is needed. The clinical background of manual placental removal, abortion, and curettage after a cesarean or repeated D&C could be ideally studied to diagnose a possible PPI. For patients with high-risk antecedents or unsure ultrasound, a T2 weight MRI is always recommended. Performing comprehensive surgical staging in PAS allows the efficient diagnosis of PPI before using some procedures.

Performance of magnetic resonance imaging to predict maternal outcomes in patients at high risk for placenta accreta spectrum disorder.

OBJECTIVE: The purpose of this study is to evaluate the diagnostic performance of MRI parameters to predict adverse maternal peripartum outcomes in pregnant females at high-risk for placenta accreta spectrum (PAS) disorder. METHODS AND MATERIALS: This retrospective study evaluated 60 pregnant females who underwent MRI for placental assessment. MRI studies were reviewed by a radiologist blinded to all clinical data. MRI parameters were compared with five maternal outcomes: severe bleeding, cesarean hysterectomy, prolonged operation time, need for blood transfusion, and need for intensive care unit (ICU) admission. The MRI findings were associated with pathologic and/or intraoperative findings for PAS. RESULTS: The study identified 46 cases of PAS disorder and 16 cases of placenta percreta. The agreement between the radiologist impression of PAS disorder and the intraoperative/histological findings was substantial (0.67, p < 0.001), and almost perfect for the presence of placenta percreta (0.87, p < 0.001). The presence of a placental bulge was highly associated with placenta percreta, with sensitivity of 87.5% and specificity of 90.9%. The MRI signs that associated with more maternal outcomes were myometrial thinning, with significant odds ratio for severe blood loss (20.2), hysterectomy (4.0), need for blood transfusion (4.8) and prolonged surgery time (4.9), and uterine bulging, with significant odds ratio for severe blood loss (11.9), hysterectomy (34.0), ICU admission (5.0), and need for blood transfusion (4.8). CONCLUSION: MRI signs significantly correlated with invasive placenta and were independently associated with adverse maternal outcomes. The presence of a placental bulge was highly accurate in predicting placenta percreta. ADVANCES IN KNOWLEDGE: First study to evaluate the strength of the association between individual MRI signs and five adverse maternal outcomes. Conclusions support published MRI signs associated with placental invasion, especially regarding the value placental bulging in predicting placenta percreta.

Bladder involvement in placenta accreta spectrum disorder with placenta previa: MRI findings and outcomes correlation.

BACKGROUND: Placental accreta spectrum (PAS) disorder with bladder involvement can be associated with maternal and neonatal morbidity. Magnetic resonance imaging (MRI) may provide accurate preoperative diagnoses. OBJECTIVE: This study had 2 aims: to retrospectively review the MRI findings for bladder involvement in PAS with placental previa and to correlate bladder involvement with maternal and neonatal outcomes. MATERIALS AND METHODS: MRI images of 48 patients with severe PAS (increta and percreta) with placenta previa/low-lying placenta were evaluated by 2 experienced radiologists blinded to the final diagnoses. Nine MRI findings and stepwise logistic regression analysis were assessed to identify predictive MRI findings for bladder involvement. The correlations between PAS patients with bladder involvement and clinical outcomes were analyzed using Fisher's exact test. RESULTS: Of the 48 patients, 27 did not have bladder involvement, while 21 did. Logistic regression analysis identified 2 predictive MRI features for bladder involvement. They were abnormal vascularization (OR,6.94; 95 %CI,1.05-45.75) and loss of the chemical shift line at the uterovesical interface (OR, 4.41; 95 %CI, 0.63-30.98). The sensitivity and specificity of the combined MRI features were 38.1 % and 100 %, respectively (p = 0.001). A significant correlation was found between bladder involvement and massive blood loss during surgery (p = 0.022). CONCLUSIONS: PAS with bladder involvement was significantly correlated with massive surgical blood loss. Prenatally, the disorder was predicted with high specificity by the combination of loss of chemical shift artifacts in the steady-state free precession sequence and abnormal vascularization at the uterovesical interface on MRI.

Risk factors of MRI findings for predicting patient outcomes of placenta accreta spectrum and placenta previa after prophylactic balloon occlusion of the internal iliac artery.

PURPOSE: Our study aimed to identify the risk factors of magnetic resonance imaging (MRI) findings for predicting patient outcomes of placenta accreta spectrum (PAS) and placenta previa after prophylactic balloon occlusion of the internal iliac artery (PBOIIA). MATERIALS AND METHODS: This retrospective analysis was performed using the clinical records of 46 patients diagnosed with PAS and placenta previa who underwent PBOIIA during caesarean section (CS). The possible clinical risk factors for adverse maternal outcomes were evaluated by consulting patients' clinical records. The inclusion criteria for the massive bleeding group were as follows: estimated blood loss (EBL) > 2500 mL, packed red blood cell (pRBC) transfusion (>4 units), and need for hysterectomy or transcatheter arterial embolization after delivery. The MRI features were compared between the massive and non-massive bleeding groups. RESULTS: Patients in the massive bleeding group (n = 22) had a significantly longer operation time (p < 0.001), more EBL (p < 0.001), more pRBC transfusions (p < 0.001), and a prolonged postoperative hospital stay (p < 0.05). MRI features showed a T2 dark bands, placenta bulge, and abnormal blood vessels in the placental bed more frequently in the massive bleeding group (p < 0.05). In the multiple logistic regression analysis, T2 dark bands (odds ratio 9.1, p = 0.048) and placental bulge (odds ratio 5.1, p = 0.014) remained statistically significant. CONCLUSION: T2 dark bands and placental bulges observed on an MRI can predict adverse maternal outcomes in patients with PAS and placenta previa undergoing PBOIIA. If these findings are observed on a preoperative MRI, effective management strategies should be prepared for the possibility of massive hemorrhage during CS.

Staged treatment of placenta accreta spectrum: A combined surgical and radiological approach.

BACKGROUND: Placenta accreta spectrum (PAS) is a rare but serious complication of pregnancy. AIMS: The aim of this study was to determine maternal and neonatal outcomes following a combined surgical and interventional radiology (IR) approach to managing PAS, and the risks associated with this technique. METHODS AND MATERIALS: Retrospective cohort study of all cases of PAS in a tertiary maternity centre between January 2001 and July 2020. Women who underwent caesarean hysterectomy for histologically confirmed PAS with a staged surgical and IR approach were compared with those who underwent caesarean hysterectomy without IR. Maternal, neonatal outcomes, surgical and radiological complications were assessed. RESULTS: Forty-six women were included in the study, and 30/46 (65.2%) underwent the staged surgical and IR approach. Women in the staged group had less overall blood loss (1794 mL vs 3713 mL; P < 0.001), less requirement for blood transfusion (40% vs 75%; P < 0.001), and a lower mean volume of packed red cells transfused (2.5 vs 6.1 units). Anaesthetic and operative times were longer for the staged group (468 vs 189 min: 272 vs 141 min P < 0.001), respectively. There were no differences in rates of neonatal or maternal complications between the two groups. CONCLUSION: This study demonstrates that a staged procedure combining surgery and IR for PAS results in a considerable reduction in blood loss, need for transfusion, and units of packed red cells transfused compared with surgery alone. The staged procedure required significantly longer anaesthetic and operative times; however, there were no differences in maternal and neonatal morbidity.

Risk factors for bladder injury during placenta accreta spectrum surgery.

OBJECTIVES: To identify risk factors associated with bladder injury during placenta accreta spectrum (PAS) surgeries. METHODS: This retrospective cohort study was conducted at the Chaim Sheba Medical Center. The study population included pregnant women diagnosed with PAS undergoing uterine-preserving surgery or hysterectomy. Women with and without operative bladder injury were compared by univariate analysis followed by multivariate analysis. A sub-analysis of women without preoperative sonographic suspicion of bladder invasion was performed. RESULTS: A total of 312 women were included in the study. Bladder injury incidence was 9.3% (n = 29). Uterine preservation was performed in 267/312 (85.6%) women. The number of previous cesarean deliveries and a preoperative sonogram suspicious for placenta percreta were found to be independent risk factors for intraoperative bladder injury (odds ratio [OR] 1.30, P = 0.019, and OR 5.23, P = 0.002, respectively). The number of previous cesarean deliveries and preoperative sonographic suspicion of placenta percreta were also associated with bladder injury in the sub-analysis (OR 1.30, P = 0.044 for previous cesarean deliveries, and OR 3.36, P = 0.036, for preoperative suspicion of bladder injury). CONCLUSION: The number of previous cesarean deliveries and preoperative suspicion of placenta percreta are preoperative factors that can assist in preoperative planning and intraoperative management of PAS cases.

Prediction of the degree of abnormal invasive placentation by obstetric history.

BACKGROUND: Diagnosis of placenta accrete spectrum (PAS) disorders is of utmost importance and mostly relies on high index of suspicion and sonographic criteria. The degree of abnormal invasive placentation is strongly associated with patients' outcomes. We aimed to determine the association between prior obstetric characteristics and the degree of PAS. METHODS: A retrospective cohort study. The study cohort comprised all women who delivered by cesarean delivery with a histopathological diagnosis of PAS during 2005-2019. We divided the cohort into 2 groups: severe PAS (increta/percreta) and mild PAS (accrete). Obstetrical characteristics and last delivery and cesarean characteristics were compared. RESULTS: Overall, 130 cases of histopathologically proven PAS were included. Of those 104 (80.0%) were mild PAS and 26 (20.0%) severe PAS. Both groups did not differ in terms of age and obstetric history. Mean parity of both study groups was 4. Intrapartum fever as noticed in 2.9-3.8% of primary cesarean (P=1.0). Cervical dilation at time of primary cesarean delivery was similar between the groups (mean 5 vs. 6 centimeters, P=0.73). Urgent cesarean delivery rate did not differ between groups (69.2% vs. 50.%, P=0.07). Method of hysterotomy closure was comparable as well. The only different variable found between groups was the rate of cephalic presentation at previous cesarean was higher in mild PAS group 69 (66.3%) vs. 11 (42.3%), P=0.024. odds ratio 2.68, 95% confidence interval 1.11-6.45. CONCLUSIONS: Discrimination of PAS severity by obstetric and previous surgical history is questionable. Our findings might be limited by sample size. Future prospective studies are warranted.

Systematic review and meta-analysis on placenta accreta spectrum disorders in twin pregnancies: risk factors, detection rate and histopathology.

INTRODUCTION: The occurrence of PAS has been recently associated with the presence of twin pregnancy. Aim of this review is to report the risk factors, histopathological correlation, diagnostic accuracy of prenatal ultrasound and clinical outcome of twin pregnancies complicated by placenta accreta spectrum (PAS) disorders. EVIDENCE ACQUISITION: PubMed, Embase, Cinahl, Clinical Trial.Gov and Google Scholar databases were searched. Inclusion criteria were studies on twin pregnancies complicated by PAS. The outcomes explored were risk factors for PAS (including placenta previa, prior uterine surgery or assisted reproductive technology, ART), histopathology (placenta accreta and increta/percreta), detection rate of prenatal ultrasound and clinical outcome, including need for blood transfusion, hysterectomy, emergency or scheduled Cesarean delivery (CD), and maternal death. Random effect meta-analyses of proportions were sued to combine the data. EVIDENCE SYNTHESIS: Two studies considering 103 pregnancies were included in this systematic review: 41.86% (95% CI 27.0-57.9) of twin pregnancies complicated by PAS disorders had a prior CD, 28.22% (95% CI 13.4-46.0) presented placenta previa and 58.14% (95% CI 42.1-73.0) of twin pregnancies were conceived by ART. 74.49% (95% CI 41.6-96.5) of PAS in twin pregnancies were placenta accreta, while 25.51% (95% CI 3.5-58.4) were placenta increta or percreta. Prenatal diagnosis of PAS in twin pregnancies was accomplished only in 27.91% (95% CI 15.3-43.7) of cases. Finally, only one study consistently reported the clinical outcome of PAS in twins. 31.67% (95% CI 20.3-45.0) of women required blood transfusion, 26.67% (95% CI 16.1-39.7) had hysterectomy, while there was no case of maternal death. 44.19% of women had an emergency CD. CONCLUSIONS: There is still limited evidence on the clinical course of PAS disorders in twin pregnancies. Placenta previa, prior uterine surgery (mainly CD), and ART are the most commonly risk factors for PAS disorders in twins. Prenatal diagnosis of PAS in twins is lower compared to what reported in singleton. Finally, about 30% of women with a twin pregnancy complicated by PAS required blood transfusion and hysterectomy.