Design of a Stem Cell-Based Therapy for Ependymal Repair in Hydrocephalus Associated With Germinal Matrix Hemorrhages.

BACKGROUND: In preterm birth germinal matrix hemorrhages (GMHs) and the consequent posthemorrhagic hydrocephalus (PHH), the neuroepithelium/ependyma development is disrupted. This work is aimed to explore the possibilities of ependymal repair in GMH/PHH using a combination of neural stem cells, ependymal progenitors (EpPs), and mesenchymal stem cells. METHODS: GMH/PHH was induced in 4-day-old mice using collagenase, blood, or blood serum injections. PHH severity was characterized 2 weeks later using magnetic resonance, immunofluorescence, and protein expression quantification with mass spectrometry. Ependymal restoration and wall regeneration after stem cell treatments were tested in vivo and in an ex vivo experimental approach using ventricular walls from mice developing moderate and severe GMH/PHH. The effect of the GMH environment on EpP differentiation was tested in vitro. Two-tailed Student t or Wilcoxon-Mann-Whitney U test was used to find differences between the treated and nontreated groups. ANOVA and Kruskal-Wallis tests were used to compare >2 groups with post hoc Tukey and Dunn multiple comparison tests, respectively. RESULTS: PHH severity was correlated with the extension of GMH and ependymal disruption (means, 88.22% severe versus 19.4% moderate). GMH/PHH hindered the survival rates of the transplanted neural stem cells/EpPs. New multiciliated ependymal cells could be generated from transplanted neural stem cells and more efficiently from EpPs (15% mean increase). Blood and TNFα (tumor necrosis factor alpha) negatively affected ciliogenesis in cells committed to ependyma differentiation (expressing Foxj1 [forkhead box J1] transcription factor). Pretreatment with mesenchymal stem cells improved the survival rates of EpPs and ependymal differentiation while reducing the edematous (means, 18% to 0.5% decrease in severe edema) and inflammatory conditions in the explants. The effectiveness of this therapeutical strategy was corroborated in vivo (means, 29% to 0% in severe edema). CONCLUSIONS: In GMH/PHH, the ependyma can be restored and edema decreased from either neural stem cell or EpP transplantation in vitro and in vivo. Mesenchymal stem cell pretreatment improved the success of the ependymal restoration.

A selective defect in the glial wedge as part of the neuroepithelium disruption in hydrocephalus development in the mouse hyh model is associated with complete corpus callosum dysgenesis.

Introduction: Dysgenesis of the corpus callosum is present in neurodevelopmental disorders and coexists with hydrocephalus in several human congenital syndromes. The mechanisms that underlie the etiology of congenital hydrocephalus and agenesis of the corpus callosum when they coappear during neurodevelopment persist unclear. In this work, the mechanistic relationship between both disorders is investigated in the hyh mouse model for congenital hydrocephalus, which also develops agenesis of the corpus callosum. In this model, hydrocephalus is generated by a defective program in the development of neuroepithelium during its differentiation into radial glial cells. Methods: In this work, the populations implicated in the development of the corpus callosum (callosal neurons, pioneering axons, glial wedge cells, subcallosal sling and indusium griseum glial cells) were studied in wild-type and hyh mutant mice. Immunohistochemistry, mRNA in situ hybridization, axonal tracing experiments, and organotypic cultures from normal and hyh mouse embryos were used. Results: Our results show that the defective program in the neuroepithelium/radial glial cell development in the hyh mutant mouse selectively affects the glial wedge cells. The glial wedge cells are necessary to guide the pioneering axons as they approach the corticoseptal boundary. Our results show that the pioneering callosal axons arising from neurons in the cingulate cortex can extend projections to the interhemispheric midline in normal and hyh mice. However, pioneering axons in the hyh mutant mouse, when approaching the area corresponding to the damaged glial wedge cell population, turned toward the ipsilateral lateral ventricle. This defect occurred before the appearance of ventriculomegaly. Discussion: In conclusion, the abnormal development of the ventricular zone, which appears to be inherent to the etiology of several forms of congenital hydrocephalus, can explain, in some cases, the common association between hydrocephalus and corpus callosum dysgenesis. These results imply that further studies may be needed to understand the corpus callosum dysgenesis etiology when it concurs with hydrocephalus.

Cognitive and emotional processing in tasks with emotional valence: Analysis of age and gender role on child development variations.

Cognitive control consists of high-level cognitive processes regulating thoughts and actions during goal-directed behavior and problem-solving. This study analyzes the performance of 4- to 8-year-old children in Stroop-like and ToL tasks using stimuli with different emotional valence. Significant differences were found in the performance in the congruent block of the Stroop-like task, where 5-year-old children presented a higher performance in the neutral condition. Also, a significant difference was only found in the incongruent block (with higher demand for inhibition), which indicates that girls performed better than boys in both task conditions. Variations in the Stroop-like task performance were found in preschoolers but not in older children, especially in girls than in boys. Specifically, these variations were found between age groups with at least two years of difference. No statistically significant differences were found in performance nor planning time in ToL between the age and gender groups in any of the task conditions. The findings highlight the need to analyze the interaction between cognitive and emotional processing, individual differences, and task demands.

Therapeutic strategies to recover ependymal barrier after inflammatory damage: relevance for recovering neurogenesis during development.

The epithelium covering the surfaces of the cerebral ventricular system is known as the ependyma, and is essential for maintaining the physical and functional integrity of the central nervous system. Additionally, the ependyma plays an essential role in neurogenesis, neuroinflammatory modulation and neurodegenerative diseases. Ependyma barrier is severely affected by perinatal hemorrhages and infections that cross the blood brain barrier. The recovery and regeneration of ependyma after damage are key to stabilizing neuroinflammatory and neurodegenerative processes that are critical during early postnatal ages. Unfortunately, there are no effective therapies to regenerate this tissue in human patients. Here, the roles of the ependymal barrier in the context of neurogenesis and homeostasis are reviewed, and future research lines for development of actual therapeutic strategies are discussed.

EEG Dynamics of Error Processing and Associated Behavioral Adjustments in Preschool Children.

Preschool children show neural responses and make behavioral adjustments immediately following an error. However, there is a lack of evidence regarding how neural responses to error predict subsequent behavioral adjustments during childhood. The aim of our study was to explore the neural dynamics of error processing and associated behavioral adjustments in preschool children from unsatisfied basic needs (UBN) homes. Using EEG recordings during a go/no-go task, we examined within-subject associations between the error-related negativity (ERN), frontal theta power, post-error slowing, and post-error accuracy. Post-error accuracy increased linearly with post-error slowing, and there was no association between the neural activity of error processing and post-error accuracy. However, during successful error recovery, the frontal theta power, but not the ERN amplitude, was associated positively with post-error slowing. These findings indicated that preschool children from UBN homes adjusted their behavior following an error in an adaptive form and that the error-related theta activity may be associated with the adaptive forms of post-error behavior. Furthermore, our data support the adaptive theory of post-error slowing and point to some degree of separation between the neural mechanisms represented by the ERN and theta.

Microplásticos, un problema de salud pública emergente

Introducción: Los productos plásticos han transformado la era moderna de tal manera que la vida sin plásticos sería irreconocible, a la par de este desarrollo la contaminación plástica es omnipresente convirtiéndose en uno de los problemas ambientales modernos más importantes. Objetivo: Compilar la información publicada en los últimos cinco años sobre la contaminación ambiental por microplásticos en Ecuador para reforzar el interés local sobre estos contaminantes. Desarrollo: Se realizó una revisión no estructurada de la literatura. Se utilizaron como bases de datos PubMed y Google Scholar. Los criterios de inclusión fueron: artículos publicados en los últimos 5 años, en idiomas inglés y español, se excluyeron otros idiomas; la selección de estudios fue de tipo a conveniencia. Se organizó y analizó cronológicamente la evidencia publicada en PubMed y Google Scholar en los últimos 5 años sobre microplásticos en Ecuador. Consideraciones finales: La información recopilada muestra cronológicamente el avance de la contaminación por microplásticos tanto a nivel mundial como en Ecuador, además, se evidencia la presencia de microplásticos en océanos, agua dulce, ecosistemas terrestres, aire, alimentos y dentro del cuerpo humano. Por lo cual la contaminación por microplásticos es un tema de gran relevancia actual, que requiere acciones de control inmediatas.

Introduction: Commercial plastic products has transformed the modern era in such a way that current life without plastic would not be possible, so at the same time with this development, plastics contamination is present, becoming one of the most urgent environmental problems nowadays. Objective: To gather available information published on the last five years concerning the microplastics as a source of environmental contamination in Ecuador and in order to reinforce the local interest on plastic pollution. Development: An unstructured review of the literature was performed. Databases used, PubMed and Google Scholar. The inclusion criteria used were as follow: articles in English and Spanish published on the last 5 years, no other language; study selections have been done by convenience. It was chronologically organized and analyzed the evidence published in PubMed and Google Scholar on the last five years concerning the microplastics behavior in Ecuador. Final considerations: The information collected chronologically shows the advancing pollution caused by microplastics both globally and in Ecuador, in addition, the presence of microplastics in oceans, fresh water, terrestrial ecosystems, air, foods and even in the human body is evident. Therefore, contamination caused by microplastics is a topic of a great importance today, which requires a speedy control action.

Introdução: Os produtos plásticos transformaram a era moderna de tal forma que a vida sem plásticos seria irreconhecível, junto com esse desenvolvimento, a poluição plástica é onipresente, tornando-se um dos mais importantes problemas ambientais modernos. Objetivo: Compilar as informações publicadas nos últimos 5 anos sobre a contaminação ambiental por microplásticos no Equador para reforçar o interesse local por esses contaminantes. Desenvolvimento: Foi realizada uma revisão não estruturada da literatura. Foram utilizadas as bases de dados PubMed e Google Scholar. Os critérios de inclusão foram: artigos publicados nos últimos 5 anos, nos idiomas inglês e espanhol, foram excluídos outros idiomas; a seleção dos estudos foi do tipo conveniência. As evidências publicadas no PubMed e Google Scholar nos últimos 5 anos sobre microplásticos no Equador foram organizadas e analisadas cronologicamente. Considerações finais: As informações coletadas cronologicamente mostram o progresso da contaminação por microplásticos tanto no mundo quanto no Equador, além disso, é evidente a presença de microplásticos nos oceanos, água doce, ecossistemas terrestres, ar, alimentos e dentro do corpo humano. Portanto, a contaminação por microplásticos é um tema de grande relevância atual, que requer ações imediatas de controle.

On the Use of Class D Switching-Mode Power Amplifiers in Visible Light Communication Transmitters.

Visible Light Communication (VLC) is a wireless communication technology that uses visible light to transmit information. The most extended implementation of a VLC transmitter employs a DC-DC power converter that biases the High-Brightness LEDs (HB-LEDs), and a Linear Power Amplifier (LPA) that reproduces the communication signal. Unfortunately, the power efficiency of LPAs is very low, thus reducing the overall system efficiency and requiring huge cooling systems to extract the heat. In this work, the use of Class D Switching-Mode Power Amplifiers (SMPAs) is explored in order to overcome that limitation. It is important to note that this SMPA is widely used for different applications, such as audio and RF power amplifiers. Therefore, there are a lot of versions of a Class D SMPA depending on the topology used for the implementation and the modulation strategy used to control the switches. Hence, this work aims to identify, adapt and explain in detail the best approach for implementing a Class D SMPA for VLC. In order to validate the proposed idea, a power-efficient VLC transmitter intended for short-range and low-speed applications was built and evaluated.

Impact of an individualized and adaptive cognitive intervention on working memory, planning and fluid reasoning processing in preschoolers from poor homes.

Contemporary evidence shows that different intervention approaches can be effective in improving executive cognitive performance in preschoolers from poor homes. However, several aspects about the role of individual and contextual differences in intervention effects remain to be elucidated. The present study aimed to explore the impact of a computerized executive cognitive intervention with lab-based tasks in preschoolers from Unsatisfied Basic Needs (UBN) homes. In the context of a randomized controlled design, different activities were administered to children according to their baseline performance in a variety of cognitive tasks tapping inhibitory control, working memory, and planning demands (i.e., high- and low-performance intervention and control groups). Results suggested that the impact of the intervention was shown preferentially by high-performers in Tower of London and K-Bit tasks, who increased their performances in the posttest assessment. This finding supports the importance of considering individual and contextual differences in the design of interventions aimed at changing the cognitive performance of children from poor homes.

Preliminary Characterization of Predictive Factors of the Visual Change after Epi-On and Epi-Off Corneal Collagen Crosslinking Techniques.

PURPOSE: To investigate the potential predictive factors of the visual change achieved with accelerated epi-on and epi-off corneal collagen crosslinking (CXL) in keratoconus. METHODS: This retrospective comparative study analyzed 67 eyes treated with an accelerated epithelium-on (epi-on group) and epithelium-off (epi-off group) CXL. The clinical outcomes were evaluated and compared during a 1-year follow-up. Likewise, the relationship of the change achieved with both CXL techniques in the corrected distance visual acuity (CDVA) with different preoperative data was investigated. RESULTS: The mean CDVA change at 3 months postoperatively was -0.04 ± 0.19 and -0.07 ± 0.25 in the epi-on and epi-off groups, respectively (p = 0.809). In the epi-on group, this change was significantly correlated with the preoperative apical (r = -0.375, p = 0.045) and central corneal thickness (r = -0.402, p = 0.031). In the epi-off group, the CDVA change was significantly correlated with not only the preoperative apical (r = 0.402, p = 0.028) and central corneal thickness (r = 0.367, p = 0.046) but also with some topometric and aberrometric indices (r ≤ -0.374, p ≤ 0.042). Furthermore, the change in CDVA in the epi-on group could be predicted from age, preoperative refractive astigmatism J45 component, anterior corneal asphericity, and posterior corneal high order aberration root mean square (p = 0.002, R 2 = 0.503). In the epi-off group, the CDVA change could be predicted from the preoperative minimum corneal thickness and magnitude of the vertical anterior corneal primary coma component (p = 0.001, R 2 = 0.446). CONCLUSIONS: Clearly, different predictive factors of the visual change induced with the accelerated epi-on and epi-off CXL techniques are present, suggesting a different mechanism of action for stiffening the cornea and inducing changes in this structure.

Corrigendum: Risks for Child Cognitive Development in Rural Contexts.

[This corrects the article DOI: 10.3389/fpsyg.2018.02735.].

Individual and socioenvironmental differences in autobiographical emotional appraisal of preschoolers.

Emotions are essential processes for integrating events into autobiographical memory. Different children react differently to the same event. The process through which these different responses are generated from subjective evaluations of an event is called emotional appraisal. The main purpose of this study was to analyze the variations in the emotional appraisal of autobiographical events of 4- and 5-year-old children from homes with different socioenvironmental conditions. We compared preschoolers' emotional appraisal responses with those of their families. The emotional accuracy of the preschoolers was found to differ according to the different socioenvironmental conditions of their homes. Greater appraisal accuracy was observed in the favorable condition, and it was greater for emotional events than for neutral events. Appraisal accuracy also differed with age, with 5-year-olds showing greater appraisal accuracy than 4-year-olds. Therefore, the emotional appraisal of these events may also be affected by age and valence when attributing emotions to personal experiences.

Efficacy and safety of a soft contact lens to control myopia progression.

CLINICAL RELEVANCE: The control of myopia progression is currently considered an evidence-based therapeutic need. BACKGROUND: To determine the efficacy and safety of the Esencia lens, a new soft contact lens (SCL) designed to slow down myopia progression in paediatric patients. METHODS: This study was a randomised, parallel, double-masked clinical trial. Seventy myopic (-0.50 to -8.75 D) boys and girls, 7-15-years of age, were randomised and allocated to one of two groups: (i) study (n = 36) or (ii) control (n = 34). Study group patients were given the Esencia lens, a progressive multifocal and reverse geometry SCL. Control group patients were given conventional SCLs. Efficacy measurements (change in cycloplegic autorefraction and axial length) were measured at baseline and at the six-month intervals over a 12- month period. Visual performance measurements were corneal power, comfort, quality of vision and contact lens fitting. Safety measures included detection of adverse events. RESULTS: Mean changes in cycloplegic autorefraction after 12-months were -0.28 ± 0.35 D for study and -0.57 ± 0.52 D for control group patients (p = 0.02). A significantly lower increase in axial length was found in the study group (0.13 ± 0.12-mm) compared to control (0.22 ± 0.14-mm) patients (p = 0.03). Compared to control group patients, there was less myopia progression in the study group: 51 and 41 per cent in terms of cycloplegic autorefraction and axial length, respectively. No significant differences between groups for change in corneal power, comfort, vision quality and contact lens fitting were found (p > 0.05). Regarding safety, there were no serious and/or unexpected adverse events during the study. CONCLUSIONS: The Esencia lens seems to be efficacious in slowing down progression of myopia in children compared to traditional SCLs in the short term, with comparable safety features and visual outcomes.

Impact of an Individualized Cognitive Training Intervention in Preschoolers from Poor Homes.

Over the last few decades, different interventions were shown to be effective in changing cognitive performance in preschoolers from poor homes undertaking tasks with executive demands. However, this evidence also showed that not all children included in the intervention groups equally increased their performance levels, which could be related to individual and contextual variability. The present study aimed to explore the impact of a computerized cognitive training intervention with lab-based tasks in preschoolers from Unsatisfied Basic Needs (UBN) homes under the consideration of their baseline performance. In the context of a randomized controlled trial design, different interventions were administered to children according to their baseline performance in a variety of cognitive tasks (i.e., executive attention, inhibitory control, working memory, and planning demands). The results showed different patterns of impact on performance depending on the experimental group, supporting the importance of considering individual and contextual differences in the design of interventions aimed at optimizing executive functions in poverty-impacted sample populations in early stages of development.

Efficient Visible Light Communication Transmitters Based on Switching-Mode dc-dc Converters.

Visible light communication (VLC) based on solid-state lighting (SSL) is a promising option either to supplement or to substitute existing radio frequency (RF) wireless communication in indoor environments. VLC systems take advantage of the fast modulation of the visible light that light emitting diodes (LEDs) enable. The switching-mode dc-to-dc converter (SMCdc-dc) must be the cornerstone of the LED driver of VLC transmitters in order to incorporate the communication functionality into LED lighting, keeping high power efficiency. However, the new requirements related to the communication, especially the high bandwidth that the LED driver must achieve, converts the design of the SMCdc-dc into a very challenging task. In this work, three different methods for achieving such a high bandwidth with an SMCdc-dc are presented: increasing the order of the SMCdc-dc output filter, increasing the number of voltage inputs, and increasing the number of phases. These three strategies are combinable and the optimum design depends on the particular VLC application, which determines the requirements of the VLC transmitter. As an example, an experimental VLC transmitter based on a two-phase buck converter with a fourth-order output filter will demonstrate that a bandwidth of several hundred kilohertz (kHz) can be achieved with output power levels close to 10 W and power efficiencies between 85% and 90%. In conclusion, the design strategy presented allows us to incorporate VLC into SSL, achieving high bit rates without damaging the power efficiency of LED lighting.

Health care and societal costs of the management of children and adolescents with attention-deficit/hyperactivity disorder in Spain: a descriptive analysis.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition in childhood (5.3% to 7.1% worldwide prevalence), with substantial overall financial burden to children/adolescents, their families, and society. The aims of this study were to describe the clinical characteristics of children and adolescents with ADHD in Spain, estimate the associated direct/indirect costs of the disorder, and assess whether the characteristics and financial costs differed between children/adolescents adequately responding to currently available pharmacotherapies compared with children/adolescents for whom pharmacotherapies failed. METHODS: This was a multicenter, cross-sectional, descriptive analysis conducted in 15 health units representative of the overall Spanish population. Data on demographic characteristics, socio-occupational status, social relationships, clinical variables of the disease, and pharmacological and non-pharmacological treatments received were collected in 321 children and adolescents with ADHD. Direct and indirect costs were estimated over one year from both a health care system and a societal perspective. RESULTS: The estimated average cost of ADHD per year per child/adolescent was €5733 in 2012 prices; direct costs accounted for 60.2% of the total costs (€3450). Support from a psychologist/educational psychologist represented 45.2% of direct costs and 27.2% of total costs. Pharmacotherapy accounted for 25.8% of direct costs and 15.5% of total costs. Among indirect costs (€2283), 65.2% was due to caregiver expenses. The total annual costs were significantly higher for children/adolescents who responded poorly to pharmacological treatment (€7654 versus €5517; P = 0.024), the difference being mainly due to significantly higher direct costs, particularly with larger expenses for non-pharmacological treatment (P = 0.012). CONCLUSIONS: ADHD has a significant personal, familial, and financial impact on the Spanish health system and society. Successful pharmacological intervention was associated with lower overall expenses in the management of the disorder.

Risks for Child Cognitive Development in Rural Contexts.

While poverty all over the world is more typical and extreme in rural contexts, interventions to improve cognition in low socioeconomic status (SES) children are for the most part based on studies conducted in urban populations. This paper investigate how poverty and rural or urban settings affect child cognitive performance. Executive functions and non-verbal intelligence performance, as well as individual and environmental information was obtained from 131 5-year-old children. For the same level of SES, children in rural settings performed consistently worse than children in urban settings. These differences could be accounted mostly by the months of past preschool attendance and the father's completed level of education. These results should inform policies and programs for children living in rural poverty worldwide, and specially in Latin America.

Pancreatectomía córporo-caudal con resección del tronco celíaco por adenocarcinoma de cuerpo pancreático: intervención de Appleby modificada / Distal pancreatectomy with celiac axis resection for adenocarcinoma of the pancreatic body: the modified Appleby procedure

La resección oncológica completa es el único procedimiento que permite la sobrevida a largo plazo en cáncer de páncreas. La afectación de la arteria hepática, tronco celíaco o arteria mesentérica superior constituyen una contraindicación quirúrgica porque se asocia a mal pronóstico y por las dificultades técnicas que implica conseguir la resección oncológica completa. Solo un grupo seleccionado de pacientes con buena respuesta a la quimioterapia y pasibles de resección R0 se benefician de la cirugía de resección del tronco celíaco. A partir de un caso clínico de un adenocarcinoma de páncreas con infiltración de la arteria hepática común y tronco celíaco que tras una buena respuesta a la neoadyuvancia y embolización de la arteria hepática común fue sometido a una esplenopancreatectomía córporo-caudal con resección del tronco celíaco, se realiza una revisión de la literatura sobre el tema y sus aspectos técnicos relevantes. El análisis realizado permite sugerir que en casos debidamente seleccionados la pancreatectomía córporo-caudal con resección del tronco celíaco en bloque es un procedimiento factible, seguro, y con buenos resultados quirúrgicos y oncológicos. En condiciones de respuesta a la quimioterapia neoadyuvante y experiencia del equipo quirúrgico pareciera que esta cirugía podría mejorar el pronóstico y calidad de vida de estos enfermos.

Abstract Complete oncologic resection is the only procedure that enables survival in pancreatic cancer. Compromise of the liver artery, the celiac artery or the superior mesenteric artery constitute a surgical contraidication since it is associated to a bad prognosis and it is technically hard to achieve a complete surgical resection. Only a selected group of patients who respond well to chemotherapy and may be subject to resection benefit from celiac artery resection surgery. A clinical case of adenocarcinoma of the pancreas with infiltration of the common liver artery and the celiac artery underwent a corporeo-caudal pancreatosplenectomy with celiac artery resection after a good response to neoadjuvant therapy and hepatic arterial embolization. Based on this, a review of literature on this issue and its relevant technical aspects was conducted. The analysis performed may suggest that in duly selected cases, corporeo-caudal pancreatosplenectomy with bloc celiac artery resection is a feasible and safe procedure with good surgical and oncologic results. Upon good response to neoadjuvant chemotherapy and an experienced surgical team, this surgery seems to improve prognosis and the quality of life of these patients.

Resumo A ressecção oncológica completa é o único procedimento que permite uma sobrevida em longo prazo a pacientes com câncer de pâncreas. O comprometimento da artéria hepática, tronco celíaco ou artéria mesentérica superior é uma contraindicação cirúrgica porque está associado a um prognóstico ruim e, devido às dificuldades técnicas que implica conseguir a ressecção oncológica completa. Somente um grupo selecionado de pacientes com boa resposta à quimioterapia e que possa ser submetido à ressecção R.0 pode se beneficiar da cirurgia de ressecção do tronco celíaco. A partir de um caso clínico de um adenocarcinoma de pâncreas com infiltração da artéria hepática comum e do tronco celíaco, que depois de apresentar boa resposta à quimioterapia e a embolização da artéria hepática comum, foi submetido a uma esplenopancreatectomia corpo-caudal com ressecção do tronco celíaco, realizou-se uma revisão da literatura sobre o tema e seus aspectos técnicos relevantes. A análise realizada permite sugerir que nos casos devidamente selecionados, a pancreatectomia corpo-caudal com ressecção em bloco do tronco celíaco é um procedimento factível, seguro, com bons resultados cirúrgicos e oncológicos. Quando se reúnem as condições de resposta adequada à quimioterapia neoadjuvante e a experiência da equipe de cirurgia, pareceria que esta intervenção poderia melhorar o prognóstico e a qualidade de vida destes pacientes.

Implicaciones pronósticas del estudio estandarizado de los márgenes de resección en el cáncer de páncreas / Prognostic implications of the standardized study of resection margins in pancreatic cancers

INTRODUCCIÓN: La afectación microscópica de los márgenes de resección es un factor pronóstico fundamental en la cirugía del cáncer de páncreas. Sin embargo, su definición anatomopatológica no está estandarizada. Este estudio pretende identificar el porcentaje real de pacientes con resecciones R1 al analizar las piezas quirúrgicas con un protocolo estandarizado y evaluar sus implicaciones sobre la supervivencia. PACIENTES Y MÉTODOS: Serie de 100 pacientes consecutivos intervenidos por adenocarcinoma ductal de páncreas y resecciones macroscópicamente completas, divididos en 2 grupos: pre- y posprotocolo, según se intervinieran antes o después de la aplicación de un protocolo estandarizado de las piezas de resección. RESULTADOS: En el grupo preprotocolo la tasa de resecciones R0 fue del 78%, mientras que tras la aplicación del mismo, se redujo al 47% (p = 0,003). El margen posterior retroperitoneal es el que se encuentra afectado con mayor frecuencia. En los casos con tumores localizados en cabeza de páncreas y analizados con el protocolo estandarizado, la detección del margen retroperitoneal afecto (R1) influye de forma negativa en la supervivencia. La mediana de supervivencia del grupo R0 fue de 22 meses frente a 16 meses en los que presentaban margen afecto (HR: 2,044; IC 95% 1,00-4,16; p = 0,043). CONCLUSIONES: La aplicación de un protocolo estandarizado para el estudio del margen retroperitoneal en el cáncer de páncreas incrementa la proporción de pacientes R1. En los pacientes con cáncer de cabeza de páncreas, la afectación del margen posterior retroperitoneal reduce significativamente la supervivencia

INTRODUCTION: Involvement of surgical resection margins is a fundamental prognostic factor in pancreatic oncological surgery. However, there is a lack of standardized histopathology definition. The aims of this study are to investigate the real rate of R1 resections when surgical specimens are evaluated according to a standardized protocol and to study its survival implications. Patients y methods: One hundred consecutive surgically resected patients with pancreatic ductal adenocarcinoma were included in the study. They were further divided in 2 groups: pre-protocol, evaluated before the introduction of the standardized protocol and post-protocol, analyzed with the standardized protocol. RESULTS: R0 resection rate in the pre-protocol group was 78%, falling to 47% after the introduction of the standardized protocol (p = 0,003). The posterior retroperitoneal margin was the most frequently involved margin. In cases with tumors located at the pancreatic head and analyzed according to the standardized protocol R1 involvement negatively affected survival. Median survival in the R0 group was 22 months versus 16 in those with the margin involved (HR: 2.044; IC 95% 1,00-4,16; P=.043). CONCLUSIONS: Standardized evaluation of the retroperitoneal margins in pancreatic cancer increases the rate of R1 patients. In cases with pancreatic cancer located at the pancreatic head involvement of posterior retroperitoneal margin significantly decreases survival

Prognostic implications of the standardized study of resection margins in pancreatic cancers.

INTRODUCTION: Involvement of surgical resection margins is a fundamental prognostic factor in pancreatic oncological surgery. However, there is a lack of standardized histopathology definition. The aims of this study are to investigate the real rate of R1 resections when surgical specimens are evaluated according to a standardized protocol and to study its survival implications. PATIENTS Y METHODS: One hundred consecutive surgically resected patients with pancreatic ductal adenocarcinoma were included in the study. They were further divided in 2 groups: pre-protocol, evaluated before the introduction of the standardized protocol and post-protocol, analyzed with the standardized protocol. RESULTS: R0 resection rate in the pre-protocol group was 78%, falling to 47% after the introduction of the standardized protocol (p=0,003). The posterior retroperitoneal margin was the most frequently involved margin. In cases with tumors located at the pancreatic head and analyzed according to the standardized protocol R1 involvement negatively affected survival. Median survival in the R0 group was 22 months versus 16 in those with the margin involved (HR: 2.044; IC 95% 1,00-4,16; P=.043). CONCLUSIONS: Standardized evaluation of the retroperitoneal margins in pancreatic cancer increases the rate of R1 patients. In cases with pancreatic cancer located at the pancreatic head involvement of posterior retroperitoneal margin significantly decreases survival.