Accuracy of sonographic lower segment thickness and prediction of vaginal birth after caesarean in a resourced-limited setting; Prospective study.

OBJECTIVES: To assess the accuracy of ultrasound measurement of the lower uterine segment (LUS) thickness against findings at laparotomy, and to investigate its correlation with the success rate of vaginal birth after one previous caesarean delivery (CD) in a resource-limited setting. DESIGN: Prospective study. SETTING: Obstetrics and Gynaecology department in a tertiary hospital in Ghana. POPULATION: Women with one previous CD undergoing either a trial of labour (TOLAC) or elective CD. METHODS: Myometrial lower uterine segment thickness (mLUS) and full lower uterine segment thickness (fLUS) were measured with transvaginal ultrasound (TVUS). The women were managed according to local protocols with the clinicians blinded to the ultrasound measurements. The LUS was measured intraoperatively for comparison with ultrasound measurements. MAIN OUTCOME MEASURES: Lower uterine segment findings at laparotomy, successful vaginal birth. RESULTS: A total of 311 pregnant women with one previous CD were enrolled; 147 women underwent elective CD and 164 women underwent a TOLAC. Of the women that underwent TOLAC, 96 (58.5%) women had a successful vaginal birth. The mLUS was comparable to the intraoperative measurement in the elective CD group with LUS thickness <5 mm (bias of 0.01, 95% CI -0.10 to 0.12 mm) whereas fLUS overestimated LUS <5 mm (bias of 0.93, 95% CI 0.80-1.06 mm). Successful vaginal birth rate correlated with increasing mLUS values (odds ratio 1.30, 95% CI 1.03-1.64). Twelve cases of uterine defect were recorded. LUS measurement ≤2.0 mm was associated with an increased risk of uterine defects with a sensitivity of 91.7% (95% CI 61.5-99.8%) and specificity of 81.8% (95% CI 75.8-86.8%). CONCLUSION: Accurate TVUS measurement of the LUS is technically feasible in a resource-limited setting. This approach could help in making safer decisions on mode of birth in limited-resource settings.

Differentiating placenta accreta spectrum from scar dehiscence with underlying, non-adherent placenta: A systematic review of scoring systems and primary data analysis.

INTRODUCTION: Accurate discrimination between placenta accreta spectrum (PAS) and scar dehiscence with underlying non-adherent placenta is challenging both on prenatal ultrasound and intraoperatively. This can lead to overdiagnosis of PAS and unnecessarily aggressive management of scar dehiscence which increases the risk of morbidity. Several scoring systems have been published which combine clinical and ultrasound information to help diagnose PAS in women at high risk. This research aims to provide insights into the reliability and utility of existing accreta scoring systems in differentiating these two closely related but different conditions to contribute to improved clinical decision making and patient outcomes. MATERIAL AND METHODS: A literature search was performed in four electronic databases. The references of relevant articles were also assessed. The articles were then evaluated according to the predefined inclusion criteria. Primary data for testing each scoring system were obtained retrospectively from two hospitals with specialized PAS services. Each scoring system was used to evaluate the predicted outcome of each case. RESULTS: The literature review yielded 15 articles. Of these, eight did not have a clearly described diagnostic criteria for accreta, hence were excluded. Of the remaining seven studies, one was excluded due to unorthodox diagnostic criteria and two were excluded as they differed from the other systems hindering comparison. Four scoring systems were therefore tested with the primary data. All the scoring systems demonstrated higher scores for high-grade PAS compared to scar dehiscence (p < 0.001) with an excellent Area Under the receiver operator characteristic Curve ranging from 0.82 (95% CI 0.71-0.92) to 0.87 (95% CI 0.79-0.96) in differentiating between these two conditions. However, no statistically significant differences were noted between the low-grade PAS and scar dehiscence on all scoring systems. CONCLUSIONS: Most published scoring systems have no clearly defined diagnostic criteria. Scoring systems can differentiate between scar dehiscence with underlying non-adherent placenta from high-grade PAS with excellent diagnostic accuracy, but not for low-grade PAS. Hence, relying solely on these scoring systems may lead to errors in estimating the risk or extent of the condition which hinders preoperative planning.

'We're like Spider-Man; with great power comes great responsibility': Coaches' experiences supporting struggling medical students.

BACKGROUND: Medical students can experience a range of academic and non-academic struggles. Coaching is a valuable strategy to support learners, but coaches describe working with struggling learners as taxing. Transformative learning theory (TLT) provides insights into how educators grow from challenging experiences to build resilience. This study explores how coaches evolve as educators through supporting struggling students. METHODS: This qualitative study grounded in an interpretivist paradigm used interviews of longitudinal medical student coaches at two academic institutions. Interviews, using TLT as a sensitizing concept, explored coaches' experience coaching struggling learners. We performed thematic analysis. RESULTS: We interviewed 15 coaches. Coaches described supporting students through multi-faceted struggles which often surprised the coach. Three themes characterized coaches' experiences: personal responsibility, emotional response, and personal learning. Coaches shouldered high personal responsibility for learners' success. For some, this burden felt emotional, raised parental instincts and questions about maintaining boundaries with learners. Coaches evolved their coaching approach, challenged biases, and built skills. Coaches learned to better appreciate the learner point of view and employ resources to support students. DISCUSSION: Through navigating learner struggles, educators can gain self-efficacy, learn to understand learners' perspectives, and evolve their coaching approach to lessen their personal emotional burden through time.

Student, Staff and Faculty Experience with a Medical School Racial and Sociopolitical Trauma Protocol: A Mixed Methods Study.

Problem: Medical students experience racial and sociopolitical trauma that disrupts their learning and wellbeing. Intervention: University of California, San Francisco (UCSF) School of Medicine students advocated for a systems approach to responding to traumatic events. Students partnered with educators to introduce an innovative protocol that affords short-term flexibility in curricular expectations (e.g., defer attendance, assignments, assessments) to empower students to rest, gather, or pursue community advocacy work. This study explored students' protocol utilization and student, staff, and faculty experience with its implementation. Context: UCSF is a public medical school with a diverse student body. Students raised the need to acknowledge the effects of trauma on their learning and wellbeing. Consequently, students and educators created the UCSF Racial and Sociopolitical Trauma protocol ('protocol') to allow students time-limited flexibility around academic obligations following events anticipated to inflict trauma on a school community level. The protocol affords students space to process events and engage with affected communities while ensuring all students achieve school competencies and graduation requirements. Impact: We conducted a two-phase mixed methods study: (1) retrospective analysis of quantitative data on students' protocol use and (2) focus groups with students, staff, and faculty. We used descriptive statistics to summarize students' protocol use to adjust attendance, assignment submission, and assessments and thematic analysis of focus group data. Across eight protocol activations June 2020 - November 2021, 357 of 664 (54%) students used it for 501 curricular activities: 56% (n = 198) for attendance, 71% (n = 252) for assignments, and 14% (n = 51) for assessments. When deciding to utilize the protocol, student focus group participants considered sources of restoration; impact on their curricular/patient responsibilities; and their identities. The protocol symbolized an institutional value system that made students feel affirmed and staff and faculty proud. Staff and faculty initially faced implementation challenges with questions around how to apply the protocol to curricular components and how it would affect their roles; however, these questions became clearer with each protocol activation. Questions remain regarding how the protocol can be best adapted for the clerkship setting. Lessons Learned: High protocol usage and focus group data confirmed that students found value in the protocol, and staff and faculty felt invested in the protocol mission. This student-initiated intervention supports a cultural shift beyond diversity toward trauma-informed medical education. Partnership among learners and educators can contribute to transforming learning and healthcare environments by enacting systems and structures that enable all learners to thrive.

Connecting Biochemistry Knowledge to Patient Care in the Clinical Workplace: Senior Medical Students' Perceptions about Facilitators and Barriers.

Phenomenon: Medical students have difficulties applying knowledge about biomedical mechanisms learned before clerkships to patient care activities. Many studies frame this challenge as a problem of basic science knowledge transfer predominantly influenced by students' individual cognitive processes. Social cognitive theory would support extending this framing to the interplay between the individual's cognition, the environment, and their behaviors. This study investigates senior medical students' experiences of biochemistry knowledge use during workplace learning and examines how their experiences were influenced by interactions with people and other elements of the clinical learning environment. Approach: The authors used a qualitative approach with a constructivist orientation. From September to November 2020 they conducted semi-structured interviews with 11 fourth-year medical students at one institution who had completed the pre-clerkship curriculum, core clinical clerkships, and the United States Medical Licensing Exam Step 1. The authors identified themes using thematic analysis. Findings: Participants reported that they infrequently used or connected to biochemistry knowledge in workplace patient care activities, yet all had examples of such connections that they found valuable to learning. Most participants felt the responsibility for making connections between biochemistry knowledge and activities in the clinical workplace should be shared between themselves and supervisors, but connections were often recognized and acted on only by the student. Connections that participants described prompted their effort to retrieve knowledge or fill a perceived learning gap. Participants identified multiple barriers and facilitators to connecting, including supervisors' behaviors and perceived knowledge, and "patients seen" in clerkships. Participants also reported learning biochemistry during USMLE Step 1 study that did not connect to patient care activities, underscoring a perception of disconnect. Insights: This study identifies specific personal, social, and physical environmental elements that influence students' perceived use of biochemistry during patient care activities. Though these findings may be most significant for biochemistry, they likely extend to other basic science disciplines. Students' self-directed efforts to connect to their biochemistry knowledge could be augmented by increased social support from clinical supervisors, which in turn likely requires faculty development. Opportunities for connection could be enhanced by embedding into the environment instructional strategies or technologies that build on known authentic connections between biochemistry and "patients seen" in clerkships. These efforts could strengthen student learning, improve clinical supervisors' self-efficacy, and better inform curriculum design.

Academic Leadership Academy Summer Program: Clerkship Transition Preparation for Underrepresented in Medicine Medical Students.

PROBLEM: Enhancing workforce diversity by increasing the recruitment of students who have been historically excluded/underrepresented in medicine (UIM) is critical to addressing healthcare inequities. However, these efforts are inadequate when undertaken without also supporting students' success. The transition to clerkships is an important and often difficult to navigate inflection point in medical training where attention to the specific needs of UIM students is critical. INTERVENTION: We describe the design, delivery, and three-year evaluation outcomes of a strengths-based program for UIM second year medical students. The program emphasizes three content areas: clinical presentations/clinical reasoning, community building, and surfacing the hidden curriculum. Students are taught and mentored by faculty, residents, and senior students from UIM backgrounds, creating a supportive space for learning. CONTEXT: The program is offered to all UIM medical students; the centerpiece of the program is an intensive four-day curriculum just before the start of students' second year. Program evaluation with participant focus groups utilized an anti-deficit approach by looking to students as experts in their own learning. During focus groups mid-way through clerkships, students reflected on the program and identified which elements were most helpful to their clerkship transition as well as areas for programmatic improvement. IMPACT: Students valued key clinical skills learning prior to clerkships, anticipatory guidance on the professional landscape, solidarity and learning with other UIM students and faculty, and the creation of a community of peers. Students noted increased confidence, self-efficacy and comfort when starting clerkships. LESSONS LEARNED: There is power in learning in a community connected by shared identities and grounded in the strengths of UIM learners, particularly when discussing aspects of the hidden curriculum in clerkships and sharing specific challenges and strategies for success relevant to UIM learners. We learned that while students found unique benefits to preparing for clerkships in a community of UIM students, near peers, and faculty, future programs could be enhanced by pairing this formal intensive curriculum with more longitudinal opportunities for community building, mentoring, and career guidance.

Ultrasound discrimination between placenta accreta spectrum and urinary bladder varices.

Distinguishing between urinary bladder varices and retroplacental neovascularization in placenta accreta spectrum in high-risk patients with placental previa is a diagnostic challenge since they have similar appearances on prenatal ultrasound. Placenta accreta spectrum is associated with massive obstetric haemorrhage while the presence of urinary bladder varices in pregnancy poses a lower surgical risk. Since the clinical implications and management approach for both conditions are entirely different, false positive diagnoses have iatrogenic consequences. In this article, we share our experiences in differentiating these two phenomena on prenatal ultrasound supported by ultrasound and intraoperative images.

Placenta accreta spectrum - variations in clinical practice and maternal morbidity between the UK and France: a population-based comparative study.

OBJECTIVE: To compare the management and outcomes of women with placenta accreta spectrum (PAS) in France and the UK. DESIGN: Two population-based cohorts. SETTING: All obstetrician-led hospitals in the UK and maternity hospitals in eight French regions. POPULATION: A cohort of 219 women with PAS in France and a cohort of 154 women with PAS in the UK. METHODS: The management and outcomes of women with PAS were compared between the UK and France. MAIN OUTCOME MEASURES: Median blood loss, severe postpartum haemorrhage (≥3 l), postpartum infection and damage to surrounding organs. RESULTS: The management of PAS differed between the two countries: a larger proportion of women with PAS in the UK had a caesarean hysterectomy compared with France (43% vs 26%, p < 0.001), whereas in France a larger proportion of women with PAS received a uterus-preserving approach compared with the UK (36% vs 19%, p < 0.001). The total median blood loss in the UK was 3 l (IQR 1.7-6.5 l), compared with 1 l (IQR 0.5-2.5 l) in France; more women with PAS had a severe postpartum haemorrhage (PPH) in the UK compared with women with PAS in France (58% vs 21%, p < 0.001) [Correction added on 06 May 2022, after first online publication: '24 hour' has been changed to 'total' in the preceding sentence]. There was no difference between the UK and French populations for postpartum infection or organ damage. CONCLUSIONS: The UK and France have very different approaches to managing PAS, with more women in France receiving a uterine-conserving approach and more women in the UK undergoing caesarean hysterectomy. A life-threatening haemorrhage was more common in the UK than in France, which may be the result of differential management and/or the organisation of the healthcare systems. In women with placenta accreta spectrum, severe haemorrhage was more common in the UK than in France. TWEETABLE ABSTRACT: In women with placenta accreta spectrum, severe haemorrhage was more common in the UK than in France.

How Do Clinical Electives during the Clerkship Year Influence Career Exploration? A Qualitative Study.

Problem: Although many students begin medical school with some idea of their specialty interest, up to 80% of these students choose a different specialty by their final year. This pivot tends to happen in the clerkship year, when students are immersed in the clinical environment, gaining a practical understanding of the day-to-day work in different fields. Yet, in this year students have limited experiences with specialties. Clinical electives during the clerkship year may aid students in career development. The authors examined student career exploration through the lens of social cognitive career theory (SCCT). SCCT posits three variables that influence career development: personal goals, self-efficacy, and understanding outcome expectations. With this framework, the authors sought to understand how a program of clinical electives during the clerkship year influences students' perceptions of their career exploration. We aimed to: (1) describe an innovative clerkship elective program designed for career exploration, and (2) explore how this influenced students' career exploration using qualitative analysis. Intervention: Beginning in 2018, students at our institution were required to participate in three 2-week clinical electives during their clerkship year, called Clinical Immersive Experiences (CIExes). CIExes were categorized into four different types: apprenticeship, clinical skills building, integrative (multi-disciplinary), or subspecialty. Authors invited fourth year students to participate in interviews (January to March 2019) about how they selected electives and how these electives contributed to their career exploration. Interviews continued until reaching information sufficiency. Authors coded and analyzed transcripts using template analysis. Context: This curricular intervention took place in the context of large-scale curricular redesign. Students began clerkships partway into their second year of medical school. The family and community medicine clerkship, which was previously a 6-week core clerkship, was changed to a longitudinal format, thus freeing up 6 weeks for electives. Other core clerkships included anesthesia (2 weeks), medicine (8 weeks), neurology (4 weeks), obstetrics and gynecology (6 weeks), pediatrics (6 weeks), psychiatry (4 weeks), and surgery (8 weeks). Impact: From 15 student interviews, we identified three major themes. First, CIExes facilitated personalized career exploration. All students felt that at least one elective helped them solidify their decision about a specialty choice. Second, CIExes promoted focused learning and skills development that complemented core rotations. They noted the benefit of positive relationships with supervisors, particularly attendings, during these electives. Third, students highlighted how these electives fostered a positive learning environment and enhanced wellbeing. SCCT clarified how the CIEx program helped students advance their personal goals, self-efficacy, and outcome expectations during a pivotal time in medical school. Lessons Learned: We learned that from the student perspective, the inclusion of clinical electives in the clerkship year benefited students' career exploration by helping them develop and refine their career goals, increase self-efficacy, and test outcome expectations in a meaningful way as anticipated from SCCT. In addition, we found that CIExes created a positive learning environment that allowed deep relationships to develop in fields of interest and that supported a strong sense of wellbeing. Supplemental data for this article is available online at https://doi.org/10.1080/10401334.2021.1891545.

The modified radical peripartum cesarean hysterectomy (Soleymani-Alazzam-Collins technique): a systematic, safe procedure for the management of severe placenta accreta spectrum.

BACKGROUND: The prevalence of placenta accreta spectrum is rising worldwide. The severe end of the spectrum where the placenta has invaded other organs is fortunately rare, however, few surgical techniques for such a complex hysterectomy have been described in the literature. OBJECTIVE: This study aimed to describe a stepwise, systematic technique for radical cesarean hysterectomy for placenta accreta spectrum to investigate outcomes for women with severe, invasive placenta accreta spectrum who were hysterectomized using this technique. STUDY DESIGN: This was a retrospective cohort study undertaken at a large UK tertiary referral center. A total of 24 cases of elective primary cesarean hysterectomy with a confirmed intrapartum diagnosis of severe percreta (Federation of Gynecology and Obstetrics grades 3b and 3c) were identified between 2011 and 2020. Among those cases, 16 had standard care (surgical technique dependent on surgeon's preference), and 8 had a radical peripartum hysterectomy using the Soleymani-Alazzam-Collins technique as described. Nonparametric testing was used because of sample size. RESULTS: The Soleymani-Alazzam-Collins technique resulted in significantly less blood loss (P=.032), more transverse incisions (P=.009), and less intensive care unit admissions (P=.046). Furthermore, there was no significant difference in theater time. CONCLUSION: The Soleymani-Alazzam-Collins technique demonstrated a significant improvement in outcomes for women with severe placenta accreta spectrum, without increasing surgical time.

When a rare condition creates a scientific society: The history of the International Society for Placenta Accreta Spectrum (IS-PAS).

Almost 10 years ago, clinicians at multiple locations all over Europe observed an increased number of antenatally undiagnosed cases of placenta accreta spectrum (PAS) resulting in significant morbidity and the occasional maternal death. Even with an improvement in antenatal imaging, the management of severe PAS remains challenging. One solution to improve understanding in rare but potentially lethal conditions is international collaboration. Consequently, a European working group was formed, which over the next few years grew into an international society, the IS-PAS. The collective goals are to develop a large shared database of cases, generate high-quality research into all aspects of PAS, and improve education of both healthcare professionals and patients. The first results of this collaboration are presented within this supplement.

The relation between maternal obesity and placenta accreta spectrum: A multinational database study.

INTRODUCTION: It has been suggested that women with obesity have increased risk of developing placenta accreta spectrum (PAS). It is unclear if this is independent of the increased risk of cesarean delivery seen with obesity itself. The aim of this study was to explore the association between maternal obesity and PAS, particularly severe PAS (percreta). MATERIAL AND METHODS: This is a cohort study based on cases recorded in the International Society for Placenta Accreta Spectrum (IS-PAS) database between April 2008 and May 2019. Multivariable logistic regression was used to explore the effect of maternal obesity on severity of PAS; this model was adjusted for other known risk factors including previous cesarean deliveries, maternal age, and placenta previa. The estimated rate of obesity in a hypothetical cohort with similar characteristics (previous cesarean delivery and same parity) was calculated and compared with the observed rate of obesity in the women of the PAS cohort (one sample test of proportions). RESULTS: Of the 386 included women with PAS, 227 (58.8%) had severe disease (percreta). In univariable analysis, maternal obesity initially appeared to be associated with increased odds of developing the most severe type of PAS, percreta (odds ratio [OR] 1.87; 95% CI 1.14-3.09); however, this association was lost after adjustment for other risk factors including previous cesarean delivery (OR 1.44; 95% CI 0.85-2.44). There was no difference in the observed rate of obesity and the rate estimated based on the risk of cesarean delivery from obesity alone (31.3% vs 36.8%, respectively; P = .07). CONCLUSIONS: Obesity does not seem to be an independent risk factor for PAS or severity for PAS. These findings are relevant for clinicians to provide accurate counseling to women with obesity regarding increased risks related to pregnancy.

Maternal and neonatal outcomes in planned versus emergency cesarean delivery for placenta accreta spectrum: A multinational database study.

INTRODUCTION: Placenta accreta spectrum (PAS) is a condition often resulting in severe maternal morbidity. Scheduled delivery by an experienced team has been shown to improve maternal outcomes; however, the benefits must be weighed against the risk of iatrogenic prematurity. The aim of this study is to investigate the rates of emergency delivery seen for antenatally suspected PAS and compare the resulting outcomes in the 15 referral centers of the International Society for PAS (IS-PAS). MATERIAL AND METHODS: Fifteen centers provided cases between 2008 and 2019. The women included were divided into two groups according to whether they had a planned or an emergency cesarean delivery. Delivery was defined as "planned" when performed at a time and date to suit the team. All the remaining cases were classified as "emergency". Maternal characteristics and neonatal outcomes were compared between the two groups according to gestation at delivery. RESULTS: In all, 356 women were included. Of these, 239 (67%) underwent a planned delivery and 117 (33%) an emergency delivery. Vaginal bleeding was the indication for emergency delivery in 41 of the 117 women (41%). There were no significant differences in terms of blood loss, transfusion rates or major maternal morbidity between planned and emergency deliveries. However, the rate of maternal intensive therapy unit admission was increased with emergency delivery (45% vs 33%, P = .02). Antepartum hemorrhage was the only independent predictor of emergency delivery (aOR: 4.3, 95% confidence interval 2.4-7.7). Emergency delivery due to vaginal bleeding was more frequent with false-positive cases (antenatally suspected but not confirmed as PAS at delivery) and the milder grades of PAS (accreta/increta). The rate of infants experiencing any major neonatal morbidity was 25% at 34+1 to 36+0  weeks and 19% at >36+0  weeks. CONCLUSIONS: Emergency delivery in centers of excellence did not increase blood loss, transfusion rates or maternal morbidity. The single greatest risk factor for emergency delivery was antenatal hemorrhage. When adequate expertise and resources are available, to defer delivery in women with no significant antenatal bleeding and no risk factors for pre-term birth until >36+0  weeks can be considered to improve fetal outcomes. Further studies are needed to investigate this fully.

Performance of antenatal imaging to predict placenta accreta spectrum degree of severity.

INTRODUCTION: In cases of placenta accreta spectrum, a precise antenatal diagnosis of the suspected degree of invasion is essential for the planning of individual management strategies at delivery. The aim of this work was to evaluate the respective performances of ultrasonography and magnetic resonance imaging for the antenatal assessment of the severity of placenta accreta spectrum disorders included in the database. The secondary objective was to identify descriptors related to the severity of placenta accreta spectrum disorders. MATERIAL AND METHODS: All the cases included in the database for which antenatal imaging data were available were analyzed. The rates of occurrence of each ultrasound and magnetic resonance imaging descriptor were reported and compared between the Group "Accreta-Increta" (FIGO grades 1 & 2) and the Group "Percreta" (FIGO grade 3). RESULTS: Antenatal imaging data were available for 347 women (347/442, 78.5%), of which 105 were included in the Group "Accreta - Increta" (105/347, 30.2%) and 213 (213/347, 61.4%) in the Group "Percreta". Magnetic resonance imaging was performed in addition to ultrasound in 135 women (135/347, 38.9%). After adjustment for all ultrasound descriptors in multivariate analysis, only the presence of a bladder wall interruption was associated with a significant higher risk of percreta (Odds ratio 3.23, Confidence interval 1.33-7.79). No magnetic resonance imaging sign was significantly correlated with the degree of severity. CONCLUSIONS: The performance of ultrasound and magnetic resonance imaging to discriminate mild from severe placenta accreta spectrum disorders is very poor. To date, the benefit of additional magnetic resonance imaging has not been demonstrated.

Minimizing surgical blood loss at cesarean hysterectomy for placenta previa with evidence of placenta increta or placenta percreta: the state of play in 2020.

The evolution of multidisciplinary team-based care for women with placenta accreta spectrum disorder has delivered stepwise improvements in clinical outcomes. Central to this overall goal is the ability to limit blood loss at surgery. Placement of inflatable balloons within the pelvic arteries, most commonly in the anterior divisions of the internal iliac arteries, became popular in many centers, at the expense of prolonging surgical care and with attendant risks of vascular injury. In tandem, the need to expose pelvic sidewall anatomy to safely identify the course of the ureters re-popularized the alternative strategy of ligating the same anterior divisions of the internal iliac arteries. With incremental gains in surgical expertise, described in 5 steps in this review, our teams have witnessed a steady decline in surgical blood loss. Nevertheless, a subset of women has the most severe form of placenta accreta spectrum, namely placenta previa-percreta. Such women are at risk of major hemorrhage during surgery from vessels arising outside the territories of the internal iliac arteries. These additional blood supplies, mostly from the external iliac arteries, pose significant risks of major blood loss even in experienced hands. To address this risk, some centers, principally in China, have adopted an approach of routinely placing an infrarenal aortic balloon, with both impressively low rates of blood loss and an ability to conserve the uterus by resecting the placenta with the affected portion of the uterine wall. We review these literature developments in the context of safely performing elective cesarean hysterectomy for placenta previa-percreta, the most severe placenta accreta spectrum disorder.

Three-dimensional US Fractional Moving Blood Volume: Validation of Renal Perfusion Quantification.

Background Three-dimensional (3D) fractional moving blood volume (FMBV) derived from 3D power Doppler US has been proposed for noninvasive approximation of perfusion. However, 3D FMBV has never been applied in animals against a ground truth. Purpose To determine the correlation between 3D FMBV and the reference standard of fluorescent microspheres (FMS) for measurement of renal perfusion in a porcine model. Materials and Methods From February 2017 to September 2017, adult pigs were administered FMS before and after measurement of renal 3D FMBV at baseline (100%) and approximately 75%, 50%, and 25% flow levels by using US machines from two different vendors. The 3D power Doppler US volumes were converted and segmented, and correlations between FMS and 3D FMBV were made with simple linear regression (r2). Similarity and reproducibility of manual segmentation were determined with the Dice similarity coefficient and 3D FMBV reproducibility (intraclass correlation coefficient [ICC]). Results Thirteen pigs were studied with 33 flow measurements. Kidney volume (mean Dice similarity coefficient ± standard deviation, 0.89 ± 0.01) and renal segmentation (coefficient of variation = 12.6%; ICC = 0.86) were consistent. The 3D FMBV calculations had high reproducibility (ICC = 0.97; 95% confidence interval: 0.96, 0.98). The 3D FMBV per-pig correlation showed excellent correlation for US machines from both vendors (mean r2 = 0.96 [range, 0.92-1.0] and 0.93 [range, 0.78-1.0], respectively). The correlation between 3D FMBV and perfusion measured with microspheres was high for both US machines (r2 = 0.80 [P < .001] and 0.70 [P < .001], respectively). Conclusion The strong correlation between three-dimensional (3D) fractional moving blood volume (FMBV) and fluorescent microspheres indicates that 3D FMBV shows excellent correlation to perfusion and good reproducibility. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Morrell et al in this issue.

Evidence-based guidelines for the management of abnormally invasive placenta: recommendations from the International Society for Abnormally Invasive Placenta.

The worldwide incidence of abnormally invasive placenta is rapidly rising, following the trend of increasing cesarean delivery. It is a heterogeneous condition and has a high maternal morbidity and mortality rate, presenting specific intrapartum challenges. Its rarity makes developing individual expertise difficult for the majority of clinicians. The International Society for Abnormally Invasive Placenta aims to improve clinicians' understanding and skills in managing this difficult condition. By pooling knowledge, experience, and expertise gained within a variety of different healthcare systems, the Society seeks to improve the outcomes for women with abnormally invasive placenta globally. The recommendations presented herewith were reached using a modified Delphi technique and are based on the best available evidence. The evidence base for each is presented using a formal grading system. The topics chosen address the most pertinent questions regarding intrapartum management of abnormally invasive placenta with respect to clinically relevant outcomes, including the following: definition of a center of excellence; requirement for antenatal hospitalization; antenatal optimization of hemoglobin; gestational age for delivery; antenatal corticosteroid administration; use of preoperative cystoscopy, ureteric stents, and prophylactic pelvic arterial balloon catheters; maternal position for surgery; type of skin incision; position of the uterine incision; use of interoperative ultrasound; prophylactic administration of oxytocin; optimal method for intraoperative diagnosis; use of expectant management; adjuvant therapies for expectant management; use of local surgical resection; type of hysterectomy; use of delayed hysterectomy; intraoperative measures to treat life-threatening hemorrhage; and fertility after conservative management.

Are women antenatally diagnosed with abnormally invasive placenta receiving optimal management in England? An observational study of planned place of delivery.

INTRODUCTION: The aim of this study was to investigate the planned place of delivery for women antenatally diagnosed with abnormally invasive placenta (AIP) in England and identify how many units regard themselves to be "specialist centers" for the management of AIP. MATERIAL AND METHODS: Observational study of obstetric-led units in England. An anonymous survey was sent to the delivery suite lead clinician in all 154 consultant-led units throughout England. The main outcome measures were whether each unit planned to manage AIP "in-house", the estimated number of AIP cases delivered in the previous 5 years and whether the unit considered itself a "specialist center" for AIP management. RESULTS: In all, 114 of 154 units responded (74%): 80 (70%) manage AIP cases "in-house", 23 (29%) of these report that they regard themselves "specialist centers" for AIP. The 23 "specialist centers" managed significantly more cases than "non-specialist centers" (5.4, 95% confidence interval (CI) 4.3-7.3 vs 2.3, 95% CI 1.5-3.1 cases/unit/year; P < .001); nearly one-third of "non-specialist centers" manage less than 1 case per year. Extrapolating the reported number of cases to all 154 obstetrician-led delivery units produces an estimate of 5.2 cases per 10 000 births over the last 5 years. CONCLUSIONS: Most units plan to manage AIP "in-house" despite encountering few cases each year. Centralizing care would allow the multidisciplinary team in each "specialist center" to develop significant experience in the management of this rare condition, leading to improved outcomes for the women.

A qualitative analysis of interprofessional students' perceptions toward patients with opioid use disorder after a patient panel experience.

Background: Students from health professional schools participated in a half-day interprofessional education workshop centered on substance use disorder training. One component was a patient panel featuring individuals with a history of opioid use disorder who described the impact of addiction on their lives and their road to recovery using varied treatment options. We hypothesized that interacting with individuals with opioid use disorder early in training would elicit more humanistic perspectives and decrease bias and stigma in future health care professionals. Methods: After participating in the panel experience, health professional students (N = 580) from medicine, nursing, pharmacy, physical therapy, and social work were asked to complete short, 5-minute, rapid reflections. Prompts asked students whether the panel changed their perception of individuals with substance use disorder, to reflect on their attitudinal changes or lack thereof, and how working in interprofessional teams could impact the management and treatment of these patients. Conventional content analysis was performed. Results: Eighty-nine percent of students who attended the session completed the rapid reflections (n = 514). Overall, approximately 70% (n = 369) of students indicated that their perceptions of individuals with substance use disorder had changed as a result of the patient panel, with students from pharmacy more likely to indicate a change in attitudes. Themes across all professions included a change toward a more humanistic perspective, value of hearing real patient stories, and learning about treatment and recovery options. Student responses described how interprofessional health care teams can provide more holistic care with a broader range of therapeutic options that may improve long-term outcomes. Conclusions: A patient panel experience is influential on interprofessional students' attitudes toward patients who suffer from opioid use disorder. Students identified an interprofessional approach as being a valuable component of management and treatment of these patients.

Placenta accreta spectrum: pathophysiology and evidence-based anatomy for prenatal ultrasound imaging.

Placenta accreta spectrum is a complex obstetric complication associated with high maternal morbidity. It is a relatively new disorder of placentation, and is the consequence of damage to the endometrium-myometrial interface of the uterine wall. When first described 80 years ago, it mainly occurred after manual removal of the placenta, uterine curettage, or endometritis. Superficial damage leads primarily to an abnormally adherent placenta, and is diagnosed as the complete or partial absence of the decidua on histology. Today, the main cause of placenta accreta spectrum is uterine surgery and, in particular, uterine scar secondary to cesarean delivery. In the absence of endometrial reepithelialization of the scar area the trophoblast and villous tissue can invade deeply within the myometrium, including its circulation, and reach the surrounding pelvic organs. The cellular changes in the trophoblast observed in placenta accreta spectrum are probably secondary to the unusual myometrial environment in which it develops, and not a primary defect of trophoblast biology leading to excessive invasion of the myometrium. Placenta accreta spectrum was separated by pathologists into 3 categories: placenta creta when the villi simply adhere to the myometrium, placenta increta when the villi invade the myometrium, and placenta percreta where the villi invade the full thickness of the myometrium. Several prenatal ultrasound signs of placenta accreta spectrum were reported over the last 35 years, principally the disappearance of the normal uteroplacental interface (clear zone), extreme thinning of the underlying myometrium, and vascular changes within the placenta (lacunae) and placental bed (hypervascularity). The pathophysiological basis of these signs is due to permanent damage of the uterine wall as far as the serosa, with placental tissue reaching the deep uterine circulation. Adherent and invasive placentation may coexist in the same placental bed and evolve with advancing gestation. This may explain why no single, or set combination of, ultrasound sign(s) was found to be specific for the depth of abnormal placentation, and accurate for the differential diagnosis between adherent and invasive placentation. Correlation of pathological and clinical findings with prenatal imaging is essential to improve screening, diagnosis, and management of placenta accreta spectrum, and standardized protocols need to be developed.