Acretismo placentário e suas complicações / Placental accretism and its complications

Acretismo é um termo genérico que significa uma invasão trofoblástica anormal da placenta em parte ou, mais raramente, na totalidade do miométrio, podendo inclusive chegar à serosa. Esse evento ocorre mais comumente em uma região de cicatriz uterina prévia, onde há um defeito na decidualização. A principal consequência disso é a necessidade frequente de histerectomia puerperal, acarretando grande morbidade materna. Este artigo apresenta o caso de uma gestante com placenta percreta, com acometimento vesical e de colo uterino que necessitou de histerectomia total. Além disso, no pós-operatório, apresentou fístula vesicoabdominal. O objetivo deste artigo é demonstrar as complicações do acretismo placentário e as maneiras de tentar reduzi-lo. O aumento nas proporções de nascimentos via parto cesariana, sem que haja evidências claras de que isso interfira na queda da mortalidade e/ou morbidade materna e neonatal, sugere que estejam sendo indicadas muito mais cesarianas que o necessário. Para redução nas taxas de cesariana e, consequentemente, das complicações dela, como nos casos de acretismo, é necessário repensar a cultura do cuidado da prática clínica em obstetrícia.(AU)

Accretism is a generic term that means an abnormal trophoblastic invasion of the placenta in part or, more rarely, in the entire myometrium, which may even reach the serosa. This event most commonly occurs in a region of previous uterine scar, where there is a decidualization defect. The main consequence of this is the frequent need for puerperal hysterectomy, causing great maternal morbidity. This article presents the case of a pregnant woman with placenta percreta, with bladder and uterine cervix involvement, who required hysterectomy. In addition, postoperatively, presented a vesico-abdominal fistula. The purpose of this article is to demonstrate the complications of placental accretism and ways to try it. The increase in the proportion of births via cesarean delivery, without clear evidences that this interferes with the decrease in maternal and neonatal mortality and/or morbidity, suggests that much more cesarean sections are being indicated than necessary. To reduce cesarean rates and consequently, its complications, as in cases of accretism, it is necessary to rethink the culture of care in clinical practice in obstetrics.(AU)

Preoperative Prophylactic Balloon-Assisted Occlusion of the Internal Iliac Arteries in the Management of Placenta Increta/Percreta.

Background and Objectives: Preoperative prophylactic balloon-assisted occlusion (PBAO) of the internal iliac arteries minimizes blood loss and facilitates surgery performance, through reductions in the rate of uterine perfusion, which allow for better control in hysterectomy performance, with decreased rates of bleeding and surgical complications. We aimed to investigate the maternal and fetal outcomes associated with PBAO use in women with placenta increta or percreta. Material and Methods: The records of 42 consecutive patients with a diagnosis of placenta increta or percreta were retrospectively reviewed. Of 42 patients, 17 patients (40.5%) with placenta increta or percreta underwent cesarean delivery after prophylactic balloon catheter placement in the bilateral internal iliac artery (balloon group). The blood loss volume, transfusion volume, postoperative hemoglobin changes, rates of hysterectomy and hospitalization, and infant Apgar score in this group were compared to those of 25 similar women who underwent cesarean delivery without balloon placement (surgical group). Results: The mean intraoperative blood loss volume in the balloon group (2319 ± 1191 mL, range 1000-4500 mL) was significantly lower than that in the surgical group (4435 ± 1376 mL, range 1500-10,500 mL) (p = 0.037). The mean blood unit volume transfused in the balloon group (2060 ± 1154 mL, range 1200-8000 mL) was significantly lower than that in the surgical group (3840 ± 1464 mL, range 1800-15,200 mL) (p = 0.043). There was no significant difference in the postoperative hemoglobin change, hysterectomy rates, length of hospitalization, or infant Apgar score between the groups. Conclusion: PBAO of the internal iliac artery prior to cesarean delivery in patients with placenta increta or percreta is a safe and minimally invasive technique that reduces the rate of intraoperative blood loss and transfusion requirements.

Control of postpartum hemorrhage in women with placenta accreta spectrum using prophylactic balloon occlusion combined with Pituitrin intra-arterial infusion.

OBJECTIVES: The aim of this study is to evaluate the efficacy of prophylactic internal iliac artery balloon occlusion combined with Pituitrin intra-arterial infusion in the control of postpartum hemorrhage in women with placenta accreta spectrum (PAS). METHODS: This is a prospective and non-randomized controlled study. The participants were assigned into three groups: without balloon catheterization (non-BC) group, balloon catheterization (BC) group, and Pituitrin combined with balloon catheterization (PBC) group. The primary outcomes were estimated blood loss (EBL) and the units of transfused packed red blood cells (PRBC). The secondary outcome was the incidence of hysterectomy. RESULTS: A total of 100 participants were recruited between August 2013 and November 2018 and assigned into the respective groups as follows: 27 in the non-BC group, 22 in the BC group, and 51 in the PBC group. No statistical differences were found in demographic characteristics among the three groups. There was a trend of lower EBL, PRBC, and hysterectomy rate in the BC group than those in the non-BC group, while all values showed no significant differences (all p > 0.05). Patients in the PBC group had significantly lower EBL, PRBC, and hysterectomy rate compared with those in the non-BC group (all p < 0.05). Linear regression analysis revealed that the PBC (vs. others) was negatively correlated with EBL and the non-BC (vs. others) independently predicted more EBL. CONCLUSIONS: Balloon occlusion combined with Pituitrin infusion is an effective treatment method which significantly reduced EBL, PRBC, and hysterectomy rate in patients with PAS. KEY POINTS: • Internal iliac artery balloon occlusion combined with Pituitrin intra-arterial infusion can significantly decrease EBL, PRBC, and hysterectomy rate during cesarean section in patients with PAS. • Cesarean section without balloon occlusion and placenta accreta depth are two independent risk factors for EBL in patients with PAS.

Placenta accreta spectrum: value of placental bulge as a sign of myometrial invasion on MR imaging.

PURPOSE: To evaluate correlation of "placental bulge sign" with myometrial invasion in placenta accreta spectrum (PAS) disorders. Placental bulge is defined as deviation of external uterine contour from expected plane caused by abnormal outward bulge of placental tissue. MATERIALS AND METHODS: In this IRB-approved, retrospective study, all patients undergoing MRI for PAS disorders between March 2014 and 2018 were included. Patients who delivered elsewhere were excluded. Imaging was reviewed by 2 independent readers. Surgical pathology from Cesarean hysterectomy or pathology of the delivered placenta was used as reference standard. Fisher's exact and kappa tests were used for statistical analysis. RESULTS: Sixty-one patients underwent MRI for PAS disorders. Two excluded patients delivered elsewhere. Placental bulge was present in 32 of 34 cases with myometrial invasion [True positive 32/34 = 94% (95% CI 0.80-0.99)]. Placental bulge was absent in 24 of 25 cases of normal placenta or placenta accreta without myometrial invasion [True negative = 24/25, 96% (95% CI 80-99.8%)]. Positive and negative predictive values were 97% and 96%, respectively. Placental bulge in conjunction with other findings of PAS disorder was 100% indicative of myometrial invasion (p < 0.01). Kappa value of 0.87 signified excellent inter-reader concordance. In 1 false positive, placenta itself was normal but the bulge was present. Surgical pathology revealed markedly thinned, fibrotic myometrium without accreta. One false-negative case was imaged at 16 weeks and may have been imaged too early. CONCLUSIONS: Placental bulge in conjunction with other findings of invasive placenta is 100% predictive of myometrial invasion. Using the bulge alone without other signs can lead to false-positive results.

Placenta percreta into the urinary bladder: the importance of the urologist.

The incidence of placenta accreta spectrum is on the rise. The most serious entity within this spectrum is percreta: extension beyond the uterus. The bladder is most commonly involved in these cases and is especially relevant for the urologist. Important sequelae include hemorrhage, massive transfusion, maternal mortality and urinary tract injury. Approaching this disorder as well as associated urinary tract involvement in a standardized and multi-disciplinary fashion significantly improves outcomes and reduces morbidity. Herein, we present a case of complete placenta percreta involving the bladder that was successfully managed with minimal obstetrical and genitourinary morbidity.

Expression of Cripto-1 in the placenta and its role in placenta accreta and placenta previa.

OBJECTIVES: This study Aims to explore the role of placental Cripto-1 in the incidence of an adherent placenta. MATERIAL AND METHODS: Ten pregnant women with placenta increta, 20 pregnant women with placenta previa and 30 women with normal pregnant were enrolled in this study. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the expression of Cripto-1 in the placenta while as the analysis of placental Cripto-1 was performed by Western blotting RESULTS: The placenta increta group showed higher levels of Cripto-1 in the center of the increta as compared to the non-implantation area. The level of placental Cripto-1 in the placenta increta was higher than that of the placenta accrete. The expression of placental Cripto-1 in the placenta increta and placenta previa groups was higher than that of control. CONCLUSIONS: Placental Cripto-1 is involved in the regulation of placental tissue invasion. Additionally, excessive placental growth or penetration into the myometrium are likely to be involved in the development of placenta increta.

Prophylactic Occlusion Balloon Placement in the Abdominal Aorta Combined with Uterine or Ovarian Artery Embolization for the Prevention of Cesarean Hysterectomy Due to Placenta Accreta: A Retrospective Study.

OBJECTIVE: To evaluate the outcomes of uterine-conserving surgery with the occlusion balloon technique followed by uterine or ovarian artery embolization (OAE) in women with placenta accreta. METHODS: A total of 31 consecutive patients, who were diagnosed with placenta accreta through grayscale ultrasonography or magnetic resonance imaging prenatally, were retrospectively analyzed in our hospital between October 2015 and September 2017. All of the women underwent a Cesarean section combined with prophylactic placement of a balloon catheter in the abdominal aorta followed by uterine artery embolization (UAE) or OAE when necessary. RESULTS: Technical success was achieved in 31 cases (100%), including successful catheterization and inflation of balloons. The uterus was conserved in 30 (96.77%) patients. The estimated blood loss, packed RBC transfused, and the operation time were 1906.45 ± 1117.64 ml, 4(0-6) U, and 88.68 ± 28.35 min, respectively. Out of all of the patients, we found nine cases of bleeding after the release of the balloon. Among these patients, six cases originated from the ovarian arteries and three cases originated from uterine arteries. Further embolization was performed through catheterization. The mean fetal radiation exposure was 4.33 ± 0.79 mGy. CONCLUSIONS: Prophylactic abdominal aorta balloon occlusion followed by UAE or OAE can effectively control postpartum hemorrhaging with reduced blood loss, transfusion requirements, and hysterectomy rates in patients with placenta accreta.

Impact of placenta previa with placenta accreta spectrum disorder on fetal growth.

OBJECTIVES: To evaluate fetal growth in pregnancies complicated by placenta previa with or without placenta accreta spectrum (PAS) disorder, compared with in pregnancies with a low-lying placenta. METHODS: This was a multicenter retrospective cohort study of singleton pregnancies complicated by placenta previa with or without PAS disorder, for which maternal characteristics, ultrasound-estimated fetal weight and birth weight were available. Four maternal-fetal medicine units participated in data collection of diagnosis, treatment and outcome. The control group comprised singleton pregnancies with a low-lying placenta (0.5-2 cm from the internal os). The diagnosis of PAS and depth of invasion were confirmed at delivery using both a predefined clinical grading score and histopathological examination. For comparison of pregnancy characteristics and fetal growth parameters, the study groups were matched for smoking status, ethnic origin, fetal sex and gestational age at delivery. RESULTS: The study included 82 women with placenta previa with PAS disorder, subdivided into adherent (n = 35) and invasive (n = 47) PAS subgroups, and 146 women with placenta previa without PAS disorder. There were 64 controls with a low-lying placenta. There was no significant difference in the incidence of small-for-gestational age (SGA) (birth weight ≤ 10th percentile) and large-for-gestational age (LGA) (birth weight ≥ 90th  percentile) between the study groups. Median gestational age at diagnosis was significantly lower in pregnancies with placenta previa without PAS disorder than in the low-lying placenta group (P = 0.002). No significant difference was found between pregnancies complicated by placenta previa with PAS disorder and those without for any of the variables. Median estimated fetal weight percentile was significantly lower in the adherent compared with the invasive previa-PAS subgroup (P = 0.047). Actual birth weight percentile at delivery did not differ significantly between the subgroups (P = 0.804). CONCLUSIONS: No difference was seen in fetal growth in pregnancies complicated by placenta previa with PAS disorder compared with those without and compared with those with a low-lying placenta. There was also no increased incidence of either SGA or LGA neonates in pregnancies with placenta previa and PAS disorder compared with those with placenta previa with spontaneous separation of the placenta at birth. Adverse neonatal outcome in pregnancies complicated by placenta previa and PAS disorder is linked to premature delivery and not to impaired fetal growth. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Multidisciplinary Approach to Placenta Percreta: An Observational Case Study.

Abnormal placental implantations can result in postpartum hemorrhage and poor outcomes. With proper diagnosis and preplanning, complications can be minimized and aligned with maternal wishes of abstaining from blood and blood product transfusions.

Updates on the management of placenta accreta spectrum.

Placenta accreta spectrum (PAS) disorders is a multifactorial process that encompasses a heterogeneous group of conditions characterized by an abnormal invasion of trophoblastic tissue through the myometrium and uterine serosa. PAS is associated with a high burden of adverse maternal outcomes including severe life-threatening hemorrhage, need for blood transfusion, damage to adjacent organs, and death. Prenatal screening of PAS is mandatory so that women may be counselled about the severity of this condition to plan management with a multidisciplinary team and delivery in a specialized center. Ultrasound during the second and third trimester is the primary tool in diagnosing PAS, while magnetic resonance imaging is generally performed to confirm the diagnosis and to delineate the topography of placental invasion. Cesarean hysterectomy with placenta left in situ between 34 and 35 weeks of gestation is currently the gold standard surgical management of PAS disorders. Conservative management, such as uterine conservation with the placenta left in situ, or "Triple-P" procedure, should be restricted to a limited number of patients who desire to preserve fertility, after an extensive counselling regarding the high maternal morbidity and mortality risks. Finally, endovascular interventional radiology has been suggested to reduce the amount of blood loss, improve visualization of the operative field and reduce surgical complications, and its use is increasing in specialized centers.

Interpregnancy interval and abnormally invasive placentation.

INTRODUCTION: The presence of a previous uterine scar is a strong risk factor for developing abnormally invasive placentation (AIP). We sought to determine whether a short interpregnancy interval predisposes to AIP. We hypothesized that a short interpregnancy interval after a previous cesarean delivery increases the risk of AIP in comparison with a longer interpregnancy interval. MATERIAL AND METHODS: We performed a retrospective cohort study of women with a histological diagnosis of AIP and a history of a previous cesarean section. Women were included in the control group if they had a previous cesarean section with a placenta underlying the previous uterine scar or an anterior previa. The time interval between pregnancy and AIP data was analyzed using the chi-square test and two-tailed Fisher's exact test. RESULTS: There was no statistical difference in the interpregnancy interval between women who had AIP vs the control group. Gravidity and parity were found to be significantly higher in the women with AIP vs the controls. CONCLUSIONS: These results suggest that a short interpregnancy interval may not increase the risk of developing AIP.

Maternal and neonatal outcomes of placenta increta and percreta from a multicenter study in China.

OBJECTIVE: The objective of this study is to identify the maternal and neonatal outcomes in women with placenta increta or placenta percreta in China. MATERIALS AND METHODS: We retrospectively analyzed 2219 cases from 20 tertiary care centers in China between January 2011 and December 2015. All cases were diagnosed of placenta increta or placenta percreta, based on either intraoperative findings or histopathological findings. RESULTS: The incidence of placenta increta and placenta percreta progressively increased from 0.18% in 2011 to 0.78% in 2015. Compared with the placenta increta, placenta percreta was strongly related to serious adverse outcomes: postpartum hemorrhage (65.9% versus 38.6%, p = .003), blood transfusion (86.2% versus 46.5%, p < .001), hysterectomy (43.3% versus 11.2%, p < .001), preterm birth (65.7% versus 49.9%, p < .001), and the need for neonatal intensive care unit (NICU) admission (54.5% versus 36.7%, p < .001). CONCLUSION: The incidence of placenta increta and placenta percreta is likely to increase in China. The depth of placenta implantation is associated with the severity of outcomes. Placenta percreta tends to have worse maternal and neonatal outcomes.

Acretismo placentario: un diagnóstico emergente. Abordaje quirúrgico no conservador / Placental accreta: an emerging diagnosis. Approach non-conservative surgical

RESUMEN El espectro de acretismo placentario es un fenómeno infrecuente del embarazo cuya incidencia ha aumentado considerablemente y que está caracterizado por el anclaje anormal de las vellosidades coriónicas al miometrio, lo cual aumenta la morbi-mortalidad materna durante la resolución quirúrgica. Según las capas uterinas comprometidas, serán clasificadas como placenta acreta (contacta miometrio), increta (penetra miometrio) y percreta (compromete todo el miometrio y/o eventualmente órganos adyacentes), siendo su mayor factor de riesgo: la cesárea anterior y la placenta previa. En este artículo se realizó una revisión bibliográfica abarcando definiciones, diagnóstico y las nuevas tendencias en manejo quirúrgico no conservador propuesto en la nueva guía de la Federación Internacional de Ginecología y Obstetricia publicada en 2018 y elaborando una discusión respecto a ellas.

SUMMARY Placenta accreta spectrum is an uncommon phenomenon of pregnancy whose incidence has increased considerably over time and is characterized by the abnormal anchoring of the chorionic villi to the myometrium, which increases maternal morbidity and mortality during surgical resolution. According to the compromised uterine layers, they will be classified as placenta accreta (contacts myometrium), increta (penetrates myometrium) and percreta (compromises the entire myometrium and / or possibly adjacent organs), being previous caesarean section and placenta previous its major risk factor. In this review, we included definitions, diagnosis, and the new topics in non-conservative surgical management developed by the International Federation of Obstetrics and Gynecolgy published in 2018, and developing a discussion of the topic.

Pathophysiology of Placenta Accreta Spectrum Disorders: A Review of Current Findings.

Current findings continue to support the concept of a biologically defective decidua rather than a primarily abnormally invasive trophoblast. Prior cesarean sections increase the risk of placenta previa and both adherent and invasive placenta accreta, suggesting that the endometrial/decidual defect following the iatrogenic creation of a uterine myometrium scar has an adverse effect on early implantation. Preferential attachment of the blastocyst to scar tissue facilitates abnormally deep invasion of trophoblastic cells and interactions with the radial and arcuate arteries. Subsequent high velocity maternal arterial inflow into the placenta creates large lacunae, destroying the normal cotyledonary arrangement of the villi.

Neuraxial Anesthesia During Cesarean Delivery for Placenta Previa With Suspected Morbidly Adherent Placenta: A Retrospective Analysis.

BACKGROUND: General anesthesia (GA) is often selected for cesarean deliveries (CD) with placenta previa and suspected morbidly adherent placenta (MAP) due to increased risk of hemorrhage and hysterectomy. We reviewed maternal outcomes and risk factors for conversion to GA in a cohort of patients undergoing CD and hysterectomy under neuraxial anesthesia (NA). METHODS: We performed a single-center, retrospective cohort study of parturients undergoing nonemergent CD for placenta previa with suspected MAP from 1997 to 2015. Patients were classified according to whether they received GA, NA, or intraoperative conversion from NA to GA. The primary outcome measure was postoperative acuity, defined as the need for intensive care unit admission, arterial embolization, reoperation, or ongoing transfusion with ≥3 units packed red blood cells. We additionally identified variables positively associated with intraoperative conversion from NA to GA during hysterectomy. Confounding was controlled with logistic regression models. RESULTS: Of 129 patients undergoing nonemergent CD for placenta previa with suspected MAP, 122 (95%) received NA as the primary anesthetic. NA was selected in the majority of patients with a body mass index ≥40 kg/m (9 of 10, 90%), a history of ≥3 prior CDs (18 of 20, 90%), suspected placenta increta or percreta (29 of 35, 83%), and Mallampati classification ≥3 (19 of 21, 90%). Of 72 patients with NA at the time of delivery who required hysterectomy, 15 (21%) required conversion to GA intraoperatively. Converted patients had a higher rate of major packed red blood cell transfusion (60% vs 25%; P = .01), with similar rates of massive transfusion (9% vs 7%; P = 1.0). Converted patients also had a higher incidence of postoperative acuity (47% vs 4%; P < .0001), including 5 intensive care unit admissions for airway management after large-volume resuscitation. After adjusting for multiple confounders, the only independent predictors of conversion among hysterectomy patients were longer surgical duration (adjusted odds ratio 1.54, 95% CI, 1.01-2.42) and a history of ≥3 prior CDs (adjusted odds ratio, 6.45; 95% CI, 1.12-45.03). CONCLUSIONS: NA was applied to and successfully used in the majority of patients with suspected MAP. Our findings support selective conversion to GA during hysterectomy in these patients, focusing on those with the highest levels of surgical complexity.

Comparison of maternal and neonatal outcomes for patients with placenta accreta spectrum between online-to-offline management model with standard care model.

OBJECTIVE: Online-to-offline is a new model for emergent medical service with the ability to connect care providers with patients on instant basis. This study aims to evaluate maternal and neonatal outcomes in patients with placenta accreta spectrum managed by an online-to-offline care model. METHODS: Starting from January 1, 2015, management of patients with placenta accreta spectrum was changed from standard care model into an online-to-offline care model through "Wechat" in Guangzhou Medical Centre for Critical Obstetrical Care. This study compared maternal and neonatal outcomes in patients affected by placenta accreta spectrum between 2015 (online-to-offline model) and 2014 (standard care model). RESULTS: A total of 209 cases of placenta accrete spectrum were treated in our center in 2015 and 218 such cases were treated in 2014. Patients treated in 2015 had lower rate of hysterectomy (14.83% versus 20.64%) and shorter hospital stay (7 days versus 8 days). The average interval from admission to emergency cesarean section for critically ill patients was 38.5 min in 2015 versus 50.7 min in 2014. CONCLUSION: Patients affected by placenta accreta spectrum managed by online-to-offline care model have reduced risk of hysterectomy, shorter hospital stay, and shorter response time from admission to emergency cesarean section.

Senescence and Telomere Homeostasis Might Be Involved in Placenta Percreta-Preliminary Investigation.

OBJECTIVE: Placenta percreta (PP) is an abnormal condition of trophoblast maturation and terminal differentiation through the uterine wall. We opted to study telomere homeostasis and senescence expression in trophoblasts from PP, the most severe subgroup of placenta accreta. STUDY DESIGN: Paraffin-embedded placental biopsies from pregnancies with percreta and normal placentation, matched by gestational age at delivery, were assessed for telomere length, aggregates, and senescence-associated heterochromatin foci using quantitative fluorescence in situ hybridization. Cyclin-dependent kinase inhibitors p21, p15, p16, and the tumor suppressor protein p53, known senescence-related markers, were assessed using immunohistochemical staining. RESULTS: Short telomeres were found more often in trophoblasts from the samples of PP (n = 9) compared to controls (n = 8; 54% ± 20% vs 2.3% ± 1.16%, respectively; P < .05). More cells with telomere aggregates (18.3% ± 6.9%) were observed in the PP than in the control group (4.8% ± 5.4%; P = .0005). The percentage of nucleic senescence-associated heterochromatin foci in the PP and control samples was similar (10.9% ± 10.4% vs 10.7% ± 15%, respectively; P = .97). Immunohistochemistry of senescence markers was expressed differently in PP compared to the controls: higher p15 expression (46.42% ± 15.2% vs 36.63% ± 12.2%, P = .004), higher p21 expression (59.8% ± 22.1% vs 47.5% ± 21.9%, P = .011), lower p16 expression (54.8% ± 26.3% vs 73.4% ± 18.9%, P = .000), and lower p53 expression (24.4% ± 33.8% vs 34% ± 14.4%, P = .000). CONCLUSION: Placenta percreta exhibits telomere alterations and changes in expression of several senescence markers. These might be related to altered trophoblast invasion maturation and placental detachment postpartum.

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.

Rotura uterina durante el segundo trimestre de gestación asociado a placenta percreta: presentación de un caso y revisión de la literature / Uterine rupture during the second trimester of pregnancy associated with placenta percreta: presentation of a case and review of the literature

OBJETIVO: Reportar el manejo de un caso de rotura uterina asociado a percretismo placentario en el segundo trimestre de gestación; y realizar una revisión de la literatura acerca del diagnóstico y tratamiento de esta condición. PRESENTACIÓN DEL CASO: Paciente de 31 años con diagnóstico intraoperatorio de rotura uterina asociada a percretismo placentario a la semana 21 de gestación. Requirió manejo quirúrgico inmediato por abdomen agudo, presentando shock hipovolémico y muerte fetal in útero. Materiales y métodos: Se realizó una búsqueda de la literatura registrada en las bases de datos entre el año 1995 y 2017 y publicados en inglés y español. Se incluyeron los reportes de y series de caso y artículos de revisión, con relación al diagnóstico prenatal y tratamiento. RESULTADOS: La mayoría de los casos reportados de rotura uterina se describen en mujeres con rotura uterina por percretismo entre la semana 9 y 34 de gestación. El tratamiento es quirúrgico en la gran mayoría de casos y su abordaje dependerá de los hallazgos intraoperatorios y condiciones médicas asociadas. CONCLUSIÓN: El acretismo placentario presentado en etapas tempranas de la gestación es rara, sin embargo, se debe sospechar según hallazgos clínicos y paraclínicos. El manejo debe estar dirigido de acuerdo al grado de invasión placentaria y situación hemodinámica, la mayoría de las veces es quirúrgico y realizado por un equipo interdisciplinario.

OBJECTIVE: To report the management of a case of uterine rupture associated with placental percreta in the second trimester of pregnancy, and to make a review of the literature about the diagnosis and treatment of this condition. PRESENTACION OF THE CASE: A 31-year-old patient with intraoperative diagnosis of uterine rupture associated with placental percretism at week 21 of gestation, who required immediate surgical intervention for acute abdomen, which developed in a hypovolemic shock and fetal death in utero. MATERIALS AND METHODS: A Research was done of the literature registered in the databases between 1995 and 2017, and published in English and Spanish. We included case reports and case series and review articles, in relation to prenatal diagnosis and treatment. RESULTS: The majority of reported cases of uterine rupture that are found in women with this condition are due to percretism between week 9 and 34 of gestation. The treatment is surgical in the great number of cases, which procedure will follow depending on the intraoperative findings and associated medical conditions. CONCLUSION: Placental accreta presented at early stages of gestation is rare, however it should be taken into account while considering the clinical and paraclinical findings. The treatment must be directed accordingly to the degree of placental invasion and hemodynamic situation, although most of the time will lead to surgery performed by an interdisciplinary team.