The Clinical Impact and Cost-Effectiveness of Surveillance of Incidentally Detected Gastric Intestinal Metaplasia: A Microsimulation Analysis.

BACKGROUND & AIMS: Gastric intestinal metaplasia (GIM) is associated with a higher risk of noncardia intestinal gastric adenocarcinoma (GA). The aim of this study was to estimate lifetime benefits, complications, and cost-effectiveness of GIM surveillance using esophagogastroduodenoscopy (EGD). METHODS: We developed a semi-Markov microsimulation model of patients with incidentally detected GIM, to compare the effectiveness of EGD surveillance with no surveillance at 10-year, 5-year, 3-year, 2-year, and 1-year intervals. We modeled a simulated cohort of 1,000,000 US individuals aged 50 with incidental GIM. Outcome measures were lifetime GA incidence, mortality, number of EGDs, complications, undiscounted life-years gained, and incremental cost-effectiveness ratio with a willingness-to-pay threshold of $100,000/quality-adjusted life-year (QALY). RESULTS: In the absence of surveillance, the model simulated 32.0 lifetime GA cases and 23.0 lifetime GA deaths per 1000 individuals with GIM, respectively. Among surveilled individuals, simulated lifetime GA incidence (per 1000) decreased with shorter surveillance intervals (10-year to 1-year, 11.2-6.1) as did GA mortality (7.4-3.6). Compared with no surveillance, all modeled surveillance intervals yielded greater life expectancy (87-190 undiscounted life-years gained per 1000); 5-year surveillance provided the greatest number of life-years gained per EGD performed and was the cost-effective strategy ($40,706/QALY). In individuals with risk factors of family history of GA or anatomically extensive, incomplete-type GIM intensified 3-year surveillance was cost-effective (incremental cost-effectiveness ratio $28,156/QALY and $87,020/QALY, respectively). CONCLUSIONS: Using microsimulation modeling, surveillance of incidentally detected GIM every 5 years is associated with reduced GA incidence/mortality and is cost-effective from a health care sector perspective. Real-world studies evaluating the impact of GIM surveillance on GA incidence and mortality in the United States are needed.

Clinical features and prognosis of malignant small bowel tumors: Experience from a university hospital in Chile.

BACKGROUND: Small bowel tumors (SBT) are infrequent and represent a small proportion of digestive neoplasms. There is scarce information about SBT in Latin America. AIM: To describe the epidemiology, clinical characteristics, diagnostic methods, and survival of malignant SBTs. METHODS: Retrospective observational study of adult patients with histopathological diagnosis of SBT between 2007 and 2021 in a university hospital in Chile. RESULTS: A total of 104 patients [51.9% men; mean age 57 years] with SBT. Histological type: neuroendocrine tumor (NET) (43.7%, n=38), gastrointestinal stromal tumors (GIST) (21.8%, n=19), lymphoma (17.2%, n=15) and adenocarcinoma (AC) (11.5%, n=10). GIST was more frequent in duodenum (50%; n=12) and NET in the ileum (65.8%; n=25). Metastasis was observed in 17 cases, most commonly from colon and melanoma. Nausea and vomiting were significantly more often observed in AC (p=0.035), as well as gastrointestinal bleeding in GIST (p=0.007). The most common diagnostic tools were CT and CT enteroclysis with an elevated diagnostic yield (86% and 94% respectively). The 5-year survival of GIST, NET, lymphoma and AC were 94.7% (95%CI: 68.1-99.2), 82.2% (95%CI: 57.6-93.3), 40.0% (95%CI: 16.5-82.8) and 25.9% (95%CI: 4.5-55.7%), respectively. NET (HR 6.1; 95%CI: 2.1-17.2) and GIST (HR 24.4; 95%CI: 3.0-19.8) were independently associated with higher survival compared to AC, adjusted for age and sex. CONCLUSIONS: Malignant SBT are rare conditions and NETs are the most common histological subtype. Clinical presentation at diagnosis, location or complications may suggest a more probable diagnosis. GIST and NET are associated with better survival compared to other malignant subtypes.

[Reduction in Helicobacter pylori infection among patients referred for upper gastrointestinal endoscopy in Santiago, Chile, between 2010-2020]. / Reducción de la infección por Helicobacter pylori en pacientes derivados a endoscopia digestiva alta en Santiago de Chile entre 2010-2020.

Latin America presents a high prevalence of Helicobacter pylori(Hp) infection. Between1996-2003, the prevalence in Santiago, Chile, was 70%; recent studies indicate a decreasein this infection. Updating the frequency of Hp is crucial due to its associated health impact. OBJECTIVE: Our objective was to describe the trend in Hp infection in patients undergoingambulatory esophagogastroduodenoscopy (EGD) in a Chilean population. MATERIALS AND METHODS: A retrospective observational study was conducted on patients over 18 years old who attended a first EGD with a rapid urease test between 2010-2020. Time trendswere described through time series analysis. A Poisson model was constructed to estimatethe risk of infection, adjusted for age and gender. RESULTS: 11,355 patients were included[66.9% females; mean age 52 years; Hp 41.6%]. Male gender presented a higher frequencyof Hp infection [RR 1.13; (95% CI: 1.08-1.18)].Hp frequency infection decreased significantlyfrom 45.1% in 2010 to 29% in 2020, with a 36% lower probability of Hp infection in 2020 compared to 2010 [RR 0.64;(95% CI: 0.55-0.74)]. A progressive decline in Hp infectiontrend was projected, reaching values close to 25% by year 2025. CONCLUSION: A significantreduction in Hpinfection was observed between 2010-2020. This decrease could be explained by the implementation of public health policies in the last decade associated with socio-sanitary changes.

Evaluation of trefoil factor 3 as a non-invasive biomarker of gastric intestinal metaplasia and gastric cancer in a high-risk population.

BACKGROUND: Adenocarcinoma is preceded by chronic atrophic gastritis, gastric intestinal metaplasia and dysplasia. Trefoil factor 3 (TFF3) is a peptide secreted by goblet cells, which is abundantly present in intestinal metaplasia. AIM: To evaluate the utility of serum TFF3 as a non-invasive biomarker for the diagnosis of intestinal metaplasia and gastric cancer. METHODS: Single-center, cross-sectional study of 274 patients who consecutively underwent upper gastrointestinal endoscopy with gastric biopsies (updated Sydney system). TFF3 levels were measured in serum by a commercial ELISA kit. Patients with normal histology or chronic atrophic gastritis without intestinal metaplasia comprised the control group. In addition, 14 patients with invasive gastric cancer were included as a reference group. The association between TFF3 levels and intestinal metaplasia was assessed by logistic regression. RESULTS: Patients with intestinal metaplasia (n=110) had a higher median TFF3 level as compared to controls (n=164), 13.1 vs. 11.9ng/mL, respectively (p=0.024). Multivariable logistic regression showed a no significant association between TFF3 levels and intestinal metaplasia (OR=1.20; 95%CI: 0.87-1.65; p-trend=0.273). The gastric cancer group had a median TFF3 level of 20.5ng/mL, and a significant association was found (OR=3.26; 95%CI: 1.29-8.27; p-trend=0.013). CONCLUSION: Serum levels of TFF3 do not discriminate intestinal metaplasia in this high-risk Latin American population. Nevertheless, we confirmed an association between TFF3 levels and invasive gastric cancer.

Implementation of the updated Sydney system biopsy protocol improves the diagnostic yield of gastric preneoplastic conditions: Results from a real-world study.

BACKGROUND: The updated Sydney system biopsy protocol (USSBP) standardizes the sampling of gastric biopsies for the detection of preneoplastic conditions (e.g., gastric intestinal metaplasia [GIM]), but the real-world diagnostic yield is not well-described. AIM: To determine whether regular application of USSBP is associated with higher detection of chronic atrophic gastritis (CAG), GIM and autoimmune gastritis (AIG). METHODS: We performed a real-world retrospective study at an academic urban tertiary hospital in Chile. We manually reviewed medical records from consecutive patients undergoing esophagogastroduodenoscopy (EGD) from January to December 2017. Seven endoscopists who performed EGDs were categorized into two groups (USSBP 'regular' and USSBP 'infrequent') based on USSBP adherence, using minimum 20% adherence as the prespecified threshold. Multivariable logistic regression models were used to estimate the odds ratios (aOR) and 95% confidence intervals (CI) for the association between endoscopist groups and the likelihood of diagnosing CAG, GIM or AIG. RESULTS: 1206 patients were included in the study (mean age: 58.5; 65.3% female). The USSBP regular group demonstrated a higher likelihood of detecting CAG (20% vs. 5.3%; aOR 4.03, 95%CI: 2.69-6.03), GIM (12.2% vs. 3.4%; aOR 3.91, 95%CI: 2.39-6.42) and AIG (2.9% vs. 0.8%; aOR 6.52, 95%CI: 1.87-22.74) compared to infrequent group. Detection of advanced-stage CAG (Operative Link for Gastritis Assessment stage III/IV) was significantly higher in the USSBP regular vs. infrequent group (aOR 5.84, 95%CI: 2.23-15.31). CONCLUSIONS: Routine adherence to USSBP increases the detection rates of preneoplastic conditions, including CAG, GIM and AIG. Standardized implementation of USSBP should be considered in high gastric cancer risk populations.

[Barrett's Esophagus: Update on the Diagnosis and Treatment. Review]. / Esófago de Barrett: Actualización en el diagnóstico y tratamiento.

Barrett's esophagus (BE) is the condition in which a metaplastic columnar mucosa predisposed to neoplasia replaces the squamous mucosa of the distal esophagus. The current guidelines recommends that diagnosis requires the finding of intestinal metaplasia (IM) with goblet cells of at least 1 cm in length. BE affects approximately 1% of the general population and up to 14% of patients with gastroesophageal reflux disease (GERD). BE is a precursor of esophageal adenocarcinoma (EAC), which has increased in western countries. The main risk factors described for EAC associated with BE are male sex, age > 50 years, central obesity and tobacco use. Annual risk of EAC in patients with BE without dysplasia, low grade (LGD) and high-grade dysplasia is 0,1-0,3%, 0,5% y 5-8%, respectively. Treatment of non-dysplastic BE consists mainly of a healthy lifestyle change, chemoprevention with proton pump inhibitors and surveillance endoscopy every 3 to 5 years. It is recommended that from the presence of LGD patients are referred to an expert center for confirmation of the diagnosis, stage and thus define their management. In patients with BE and dysplasia or early-stage cancer, endoscopic therapy with resection and ablation is successful in about 90% of the patients. The main adverse event is esophageal stricture, which is managed endoscopically.

Mucocutaneous Manifestations in Autoimmune Gastritis: A Prospective Case-Control Study.

INTRODUCTION: Autoimmune gastritis (AIG) is associated with nutritional deficiencies, autoimmune diseases, and gastric malignancies. The aims of the study were to test the hypothesis that mucocutaneous (MC) manifestations occur more often in patients with vs without AIG and to delineate patterns of MC manifestations in AIG. METHODS: A single-center, prospective 2:1 case-control study was conducted. Cases were patients with the diagnosis of AIG based on consistent serologic and histologic findings. Controls had a normal gastric biopsy. MC manifestations were independently evaluated by 3 experienced dermatologists. We conducted a multivariable logistic regression model adjusted for age, sex, Helicobacter pylori, tobacco use, and alcohol consumption to estimate the association between AIG (vs no AIG) and MC manifestations (adjusted odds ratio; 95% confidence interval). RESULTS: We prospectively enrolled 60 cases and 30 controls (mean age 53.5 ± 15.8 vs 53.4 ± 14.5 years; 75% vs 73.3% women). The pooled prevalence of MC immune-mediated diseases was higher in patients with vs without AIG (66.7% vs 23.3%; adjusted odds ratio 12.01 [95% confidence interval: 3.51-41.13]). In patients with AIG, seropositive vs seronegative anti-intrinsic factor antibodies more often had concomitant immunological diseases with MC manifestations (100% vs 58.5%; P = 0.016). The most common MC immune-mediated diseases in AIG were Sjögren syndrome (n = 5, 8.3%), alopecia areata (n = 5, 8.3%), and vitiligo (n = 4, 6.7%). Nutritional deficiency-related MC findings, mainly xerosis, lingual, and nail disorders, were also more common in AIG. DISCUSSION: This is the first comparative study specifically designed to evaluate MC manifestations in AIG. We demonstrated that AIG is more frequently associated with both immune- and nutritional deficiency-related MC manifestations, which might have both diagnostic and therapeutic clinical implications.

[Educational impact after 10 years of implementation of a portfolio for undergraduate medical students]. / Portafolio en pregrado de Medicina: impacto educacional a 10 años de su implementación.

BACKGROUND: A portfolio is a compilation of academic work that demonstrates student's knowledge, reflection and critical thinking. AIM: To describe the development and implementation of an undergraduate portfolio in the School of Medicine at the Pontificia Universidad Católica de Chile, its temporal evolution and its educational impact after 10 years of experience. MATERIAL AND METHODS: The development and implementation of a portfolio for 4th-year undergraduate medical student was analyzed. Its design, teaching and learning methodologies, results and perceptions of students and teachers were assessed. The educational impact was measured using Kirkpatrick's levels. RESULTS: A total of 1,320 students participated between 2007 and 2017, supported by six teachers and 190 assistant-students. The portfolio included clinical cases, narrative medicine, palliative care and evidence-based medicine (EBM). The overall student's perception was positive, highlighting the development of critical analysis, clinical reasoning and professionalism. The delivery of feedback and learning assessment, allowed students to obtain excellent grades. There were only two cases of plagiarism reported. Fifteen EBM articles and two books with 52 narrative medicine essays were published. The greatest organizational impact of this teaching innovation, was that it evolved to become an established and continuous assessment instrument in 10 consecutive years. CONCLUSIONS: This portfolio is a project with a high educational impact, with a favorable perception by students and tutors, excellent results related to grades, stimulating both scientific writing and reflective practice.

Early pregnancy thyroid hormone reference ranges in Chilean women: the influence of body mass index.

OBJECTIVE: Thyroid dysfunction and obesity during pregnancy have been associated with negative neonatal and obstetric outcomes. Thyroid hormone reference ranges have not been established for the pregnant Hispanic population. This study defines thyroid hormone reference ranges during early pregnancy in Chilean women and evaluates associations of body mass index (BMI) with thyroid function. DESIGN, PATIENTS, MEASUREMENTS: This is a prospective observational study of 720 healthy Chilean women attending their first prenatal consultation at an outpatient clinic. Thyroid function [TSH, Free T4, Total T4 and antithyroid peroxidase antibodies (TPOAb)] and BMI were assessed at 8·8 ± 2·4 weeks of gestational age. RESULTS: Median, 2·5th percentile (p2·5), and 97·5th percentile (p97·5) TSH values were higher, while median, p2·5, and p97·5 free T4 values were lower in obese patients compared with normal weight patients. Obesity was associated with a median TSH 16% higher (P = 0·035) and a median free T4 6·5% lower (P < 0·01) than values from patients with normal weight. BMI had a small, but statistically significant effect on TSH (P = 0·04) and free T4 (P < 0·01) when adjusted by maternal age, TPO antibodies, parity, sex of the newborn, gestational age and smoking. In all TPOAb (-) patients, median (p2·5-p.97·5) TSH was 1·96 mIU/l (0·11-5·96 mIU/l) and median (p2·5-p.97·5) free T4 was 14·54 pmol/l (11·1 - 19·02 pmol/l). Applying these reference limits, we found a prevalence of overt and subclinical hypothyroidism of 0·9% and 3·05% respectively. CONCLUSIONS: TSH distributes at higher values and free T4 at lower values in obese pregnant women compared to normal weight pregnant women. Thyroid hormone reference ranges derived from Chilean patients with negative TPOAb are different from the fixed internationally proposed reference ranges and may be used in the Hispanic population.

[Development of MEDUC-PG14 survey to assess postgraduate teaching in medical specialties]. / Evaluación de docentes clínicos de Postgrado: desarrollo y propiedades psicométricas del instrumento MEDUC-PG14.

BACKGROUND: Feedback is one of the most important tools to improve teaching in medical education. AIM: To develop an instrument to assess the performance of clinical postgraduate teachers in medical specialties. MATERIAL AND METHODS: A qualitative methodology consisting in interviews and focus-groups followed by a quantitative methodology to generate consensus, was employed. After generating the instrument, psychometric tests were performed to assess the construct validity (factor analysis) and reliability (Cronbach’s alpha). RESULTS: Experts in medical education, teachers and residents of a medical school participated in interviews and focus groups. With this information, 26 categories (79 items) were proposed and reduced to 14 items (Likert scale 1-5) by an expert’s Delphi panel, generating the MEDUC-PG14 survey, which was answered by 123 residents from different programs of medical specialties. Construct validity was carried out. Factor analysis showed three domains: Teaching and evaluation, respectful behavior towards patients and health care team, and providing feedback. The global score was 4.46 ± 0.94 (89% of the maximum). One teachers’ strength, as evaluated by their residents was “respectful behavior” with 4.85 ± 0.42 (97% of the maximum). “Providing feedback” obtained 4.09 ± 1.0 points (81.8% of the maximum). MEDUC-PG14 survey had a Cronbach’s alpha coefficient of 0.947. CONCLUSIONS: MEDUC-PG14 survey is a useful and reliable guide for teacher evaluation in medical specialty programs. Also provides feedback to improve educational skills of postgraduate clinical teachers.

Prevalence of lactose intolerance in Chile: a double-blind placebo study.

BACKGROUND AND STUDY AIMS: Lactase non-persistence (LNP), or primary hypolactasia, is a genetic condition that mediates lactose malabsorption and can cause lactose intolerance. Here we report the prevalence of lactose intolerance in a double-blind placebo study. METHODS: The LCT C>T-13910 variant was genotyped by RT-PCR in 121 volunteers and lactose malabsorption was assessed using the hydrogen breath test (HBT) after consuming 25 g of lactose. Lactose intolerance was assessed by scoring symptoms (SS) using a standardized questionnaire following challenge with a lactose solution or saccharose placebo. RESULTS: The LNP genotype was observed in 57% of the volunteers, among whom 87% were HBT⁺. In the HBT⁺ group the median SS was 9 and in the HBT⁻ group the median SS was 3 (p < 0.001). No difference was observed in the SS when both groups were challenged with the placebo. The most common symptoms included audible bowel sounds, abdominal pain and meteorism. In the ROC curve analysis, an SS ≥ 6 demonstrated 72% sensitivity and 81% specificity for predicting a positive HBT. To estimate prevalence, lactose intolerance was defined as the presence of an SS ≥ 6 points after subtracting the placebo effect and 34% of the study population met this definition. CONCLUSIONS: The LNP genotype was present in more than half of subjects evaluated and the observed prevalence of lactose intolerance was 34%.

Quadruple therapies show a higher eradication rate compared to standard triple therapy for Helicobacter pylori infection within the LEGACy consortium. A multicenter observational study in European and Latin American countries.

INTRODUCTION: Gastric cancer (GC) is one of the most lethal malignancies worldwide. Helicobacter pylori is the primary cause of GC; therefore, its eradication reduces the risk of developing this neoplasia. There is extensive evidence regarding quadruple therapy with relevance to the European population. However, in Latin America, data are scarce. Furthermore, there is limited information about the eradication rates achieved by antibiotic schemes in European and Latin American populations. OBJECTIVE: To compare the effectiveness of standard triple therapy (STT), quadruple concomitant therapy (QCT), and bismuth quadruple therapy (QBT) in six centers in Europe and Latin America. METHODS: A retrospective study was carried out based on the LEGACy registry from 2017 to 2022. Data from adult patients recruited in Portugal, Spain, Chile, Mexico, and Paraguay with confirmed H. pylori infection who received eradication therapy and confirmatory tests at least 1 month apart were included. Treatment success by each scheme was compared using a mixed multilevel Poisson regression, adjusting for patient sex and age, together with country-specific variables, including prevalence of H. pylori antibiotic resistance (clarithromycin, metronidazole, and amoxicillin), and CYP2C19 polymorphisms. RESULTS: 772 patients were incorporated (64.64% females; mean age of 52.93 years). The total H. pylori eradication rates were 75.20% (255/339) with STT, 88.70% (159/178) with QCT, and 91.30% (191/209) with QBT. Both quadruple therapies (QCT-QBT) showed significantly higher eradication rates compared with STT, with an adjusted incidence risk ratio (IRR) of 1.25 (p: <0.05); and 1.24 (p: <0.05), respectively. The antibiotic-resistance prevalence by country, but not the prevalence of CYP2C19 polymorphism, showed a statistically significant impact on eradication success. CONCLUSIONS: Both QCT and QBT are superior to STT for H. pylori eradication when adjusted for country-specific antibiotic resistance and CYP2C19 polymorphism in a sample of individuals residing in five countries within two continents.

Autoimmune Diseases and Gastric Cancer Risk: A Systematic Review and Meta-Analysis.

PURPOSE: Autoimmunity is an alternative etiology of gastric inflammation, the initiating event in the gastric carcinogenic cascade. This mechanism may be an increasingly important cause of gastric cancer with the waning prevalence of its primary etiologic factor, chronic Helicobacter pylori infection. MATERIALS AND METHODS: PubMed and EMBASE were searched up to September 2018. Autoimmunity and 96 specific manifestations were considered for associations with gastric cancer risk. Random effects analysis was used to calculate pooled relative risk estimates (RR) and 95% confidence intervals (CI). RESULTS: We found a total of 52 observational studies representing 30 different autoimmune diseases. Overall, the presence of an autoimmune condition was associated with a gastric cancer pooled RR of 1.37 (95% CI, 1.24 to 1.52). Among the 24 autoimmune conditions with two or more independent reports, nine were significantly associated with increased gastric cancer risk: dermatomyositis (RR, 3.69; 95% CI, 1.74 to 7.79), pernicious anemia (RR, 2.84; 95% CI, 2.30 to 3.50), Addison disease (RR, 2.11; 95% CI, 1.26 to 3.53), dermatitis herpetiformis (RR, 1.74; 95% CI, 1.02 to 2.97; n=3), IgG4-related disease (RR, 1.69; 95% CI, 1.00 to 2.87), primary biliary cirrhosis (RR, 1.64; 95% CI, 1.13 to 2.37), diabetes mellitus type 1 (RR, 1.41; 95% CI, 1.20 to 1.67), systemic lupus erythematosus (RR, 1.37; 95% CI, 1.01 to 1.84), and Graves disease (RR, 1.27; 95% CI, 1.06 to 1.52). CONCLUSION: Our analysis documents the wide range of autoimmune diseases associated with gastric cancer. These associations may reflect unreported links between these conditions and autoimmune gastritis. Further studies are warranted to investigate potential causal mechanisms.

Reducción de la infección por Helicobacter pylori en pacientes derivados a endoscopia digestiva alta en Santiago de Chile entre 2010-2020 / Reduction in Helicobacter pylori infection among patients referred for upper gastrointestinal endoscopy in Santiago, Chile, between 2010-2020

RESUMEN Latinoamérica presenta una alta prevalencia de infección por Helicobacter pylori (Hp). Entre 1996-2003 la prevalencia en Santiago de Chile fue del 70%; estudios recientes presentan una disminución en esta infección. Actualizar la frecuencia de Hp es fundamental debido a su impacto en la salud asociado. Objetivo: Nuestro objetivo fue describir la tendencia de la infección por Hp en pacientes que asisten a endoscopía digestiva alta (EDA) ambulatoria en una población chilena. Materiales y métodos: Se realizó un estudio observacional retrospectivo de pacientes mayores de 18 años que asistieron a una primera EDA con test rápido de ureasa entre 2010-2020. La tendencia en el tiempo fue descrita mediante análisis de series de tiempo. Se construyó un modelo Poisson para estimar el riesgo de infección, ajustado por edad y sexo. Resultados: Se incluyeron 11 355 pacientes [66,9% mujeres; edad media 52 años; Hp 41,6%]. El sexo masculino presentó una mayor frecuencia de infección por Hp [RR 1,13; (IC95%:1,08-1,18)]. La frecuencia de Hp disminuyó significativamente desde 45,1% en 2010 hasta 29% en 2020, con 36% menor probabilidad de presentar infección por Hp en 2020 con respecto al 2010 [RR 0,64; (IC95%:0,55-0,74)]. Se proyectó un descenso progresivo en la tendencia de infección por Hp hasta valores cercanos al 25% para el año 2025. Conclusión: Se observó una reducción significativa en la infección por Hp entre los años 2010-2020. Esta disminución pudiese ser explicada mediante la incorporación de políticas públicas de salud en la última década asociadas a cambios sociosanitarios.

ABSTRACT Latin America presents a high prevalence of Helicobacter pylori (Hp) infection. Between 1996-2003, the prevalence in Santiago, Chile, was 70%; recent studies indicate a decrease in this infection. Updating the frequency of Hp is crucial due to its associated health impact. Objective: Our objective was to describe the trend in Hp infection in patients undergoing ambulatory esophagogastroduodenoscopy (EGD) in a Chilean population. Materials and methods: A retrospective observational study was conducted on patients over 18 years old who attended a first EGD with a rapid urease test between 2010-2020. Time trends were described through time series analysis. A Poisson model was constructed to estimate the risk of infection, adjusted for age and gender. Results: 11,355 patients were included [66.9% females; mean age 52 years; Hp 41.6%]. Male gender presented a higher frequency of Hp infection [RR 1.13; (95% CI: 1.08-1.18)]. Hp frequency infection decreased significantly from 45.1% in 2010 to 29% in 2020, with a 36% lower probability of Hp infection in 2020 compared to 2010 [RR 0.64; (95% CI: 0.55-0.74)]. A progressive decline in Hp infection trend was projected, reaching values close to 25% by year 2025. Conclusion: A significant reduction in Hp infection was observed between 2010-2020. This decrease could be explained by the implementation of public health policies in the last decade associated with socio-sanitary changes.

Esófago de Barrett: Actualización en el diagnóstico y tratamiento

El esófago de Barrett (EB) se define como la condición en la cual una mucosa columnar metaplásica predispuesta a neoplasia reemplaza la mucosa escamosa del esófago distal. La guías actuales recomiendan que el diagnóstico requiere el hallazgo de metaplasia intestinal (MI) con células caliciformes de al menos 1 cm de longitud. El EB afecta aproximadamente al 1% de la población general y hasta en 14% de los pacientes con enfermedad por reflujo gastroesofágico (ERGE). El EB es precursor del adenocarcinoma esofágico (ACE), neoplasia en aumento en países occidentales. Los principales factores de riesgo descritos para ACE asociado a EB son: sexo masculino, edad > 50 años, obesidad central y tabaquismo. El riesgo anual de ACE en EB sin displasia, displasia de bajo (DBG) y alto grado es 0,1-0,3%, 0,5% y 5-8%, respectivamente. El tratamiento del EB no displásico consiste en un cambio de estilo de vida saludable, quimioprevención mediante inhibidores de la bomba de protones y vigilancia endoscópica cada 3 a 5 años. Se recomienda que a partir de la presencia de DBG los pacientes sean referidos a un centro experto para la confirmación del diagnóstico, estadio y así definir su manejo. En pacientes con EB y displasia o cáncer incipiente, el tratamiento endoscópico consiste en la resección y ablación, con un éxito cercano al 90%. El principal evento adverso es la estenosis esofágica que es manejada endoscópicamente.

Barrett's esophagus (BE) is the condition in which a metaplastic columnar mucosa predisposed to neoplasia replaces the squamous mucosa of the distal esophagus. The current guidelines recommends that diagnosis requires the finding of intestinal metaplasia (IM) with goblet cells of at least 1 cm in length. BE affects approximately 1% of the general population and up to 14% of patients with gastroesophageal reflux disease (GERD). BE is a precursor of esophageal adenocarcinoma (EAC), which has increased in western countries. The main risk factors described for EAC associated with BE are male sex, age > 50 years, central obesity and tobacco use. Annual risk of EAC in patients with BE without dysplasia, low grade (LGD) and high-grade dysplasia is 0,1-0,3%, 0,5% y 5-8%, respectively. Treatment of non-dysplastic BE consists mainly of a healthy lifestyle change, chemoprevention with proton pump inhibitors and surveillance endoscopy every 3 to 5 years. It is recommended that from the presence of LGD patients are referred to an expert center for confirmation of the diagnosis, stage and thus define their management. In patients with BE and dysplasia or early-stage cancer, endoscopic therapy with resection and ablation is successful in about 90% of the patients. The main adverse event is esophageal stricture, which is managed endoscopically.

Portafolio en pregrado de Medicina: impacto educacional a 10 años de su implementación / Educational impact after 10 years of implementation of a portfolio for undergraduate medical students

Background: A portfolio is a compilation of academic work that demonstrates student's knowledge, reflection and critical thinking. Aim: To describe the development and implementation of an undergraduate portfolio in the School of Medicine at the Pontificia Universidad Católica de Chile, its temporal evolution and its educational impact after 10 years of experience. Material and Methods: The development and implementation of a portfolio for 4th-year undergraduate medical student was analyzed. Its design, teaching and learning methodologies, results and perceptions of students and teachers were assessed. The educational impact was measured using Kirkpatrick's levels. Results: A total of 1,320 students participated between 2007 and 2017, supported by six teachers and 190 assistant-students. The portfolio included clinical cases, narrative medicine, palliative care and evidence-based medicine (EBM). The overall student's perception was positive, highlighting the development of critical analysis, clinical reasoning and professionalism. The delivery of feedback and learning assessment, allowed students to obtain excellent grades. There were only two cases of plagiarism reported. Fifteen EBM articles and two books with 52 narrative medicine essays were published. The greatest organizational impact of this teaching innovation, was that it evolved to become an established and continuous assessment instrument in 10 consecutive years. Conclusions: This portfolio is a project with a high educational impact, with a favorable perception by students and tutors, excellent results related to grades, stimulating both scientific writing and reflective practice.

Diseño e implementación de un modelo de enseñanza en ambiente simulado de paracentesis abdomina / Design and implementation of an environment teaching model simulated abdominal paracentesis

Resumen: El aprendizaje de los estudiantes de Medicina de Pregrado en ambiente simulado constituye una alternativa en la obtención de competencias técnicas y no técnicas. Objetivo: Desarrollar un fantoma e implementar un taller modular de entrenamiento de paracentesis abdominal en ambiente simulado para estudiantes de Medicina. Métodos: Se diseñaron y desarrollaron modelos para la realización de paracentesis abdominal en la Escuela de Diseño de la Pontificia Universidad Católica de Chile (PUC) y se implementó un taller para alumnos de 4to año de Medicina de la PUC, utilizando un enfoque constructivista, sesiones de entrenamiento simulado con debriefing basadas en el modelo plus-delta y evaluación pre y post-procedimiento siguiendo los principios de evaluación para el aprendizaje. Resultados: Se desarrollaron 3 prototipos hasta llegar a un modelo definitivo de alta fidelidad basado en la percepción de 20 expertos. 237 alumnos asistieron a un taller de paracentesis abdominal en el Centro de Cirugía Experimental y Simulación Universidad Católica (UC). Este consistió en una actividad práctica grupal (7-8 alumnos por sesión) que incluyó: una evaluación pre-sesión, un vídeo instruccional, una demostración en tiempo real en el fantoma por parte de un docente, la realización guiada del procedimiento por parte de los alumnos, debriefing y cierre de la sesión. Conclusiones: Un modelo de enseñanza en ambiente simulado es posible de ser diseñado e implementado exitosamente en un centro educacional para estudiantes de Medicina de Pregrado. Este taller de paracentesis permite entrenar a los alumnos en la realización de paracentesis abdominal en un ambiente seguro para los alumnos y pacientes y puede ser implementado a bajo costo en otros centros o instituciones. (AU)

Abstract: Simulated environments are an option in the learning process of undergraduate medical students in order to obtain technical and non-technical. Aim: To develop a mannequin for abdominal paracentesis and the implementation of a training workshop to perform abdominal paracentesis in a simulated environment for undergraduate medical students. Methods: The prototypes were designed and developed to perform abdominal paracentesis at the School of Design at the Pontificia Universidad Católica de Chile (PUC) and a workshop was implemented in a course with 4-year medical students at the PUC, using a constructivist approach and simulated training sessions and providing debriefing (based on plus-delta model) and pre-post training assessment following the principles of Assessment for Learning. Results: Three prototypes were developed until the final high-fidelity-mannequin was achieved. The abdominal paracentesis workshop was attended by 237 students at the Universidad Católica (UC) Experimental Surgery and Simulation Center. This was a hands-on group activity (7-8 students per session) including pre-session assessment, instructional video-tape, real-time demonstration of abdominal paracentesis procedure by the clinical teacher, followed by abdominal paracentesis performed by the students, debriefing and closing session. Conclusions: A teaching model in a simulated environment is feasible to be successfully designed and implemented in an educational center for undergraduate medical students. This workshop allows students training process to perform abdominal paracentesis in a safe environment for students and patients and it can be implemented in other centers or institutions with low cost.(AU)