RESUMO Racional: A identificação de fatores prognósticos do câncer gástrico (GC) permitiu predizer a evolução dos pacientes. Objetivo: Avaliar a confiabilidade do índice linfoparietal na predição de sobrevida em longo prazo em pacientes tratados com intenção curativa. Método: Estudo prospectivo do Hospital das Clínicas da Universidade de Chile, entre maio de 2004 e maio de 2012. Todas as operações de câncer gástrico foram com intenção curativa. Os critérios de exclusão foram: gastrectomia por lesões benignas, cânceres estágio 4, ressecções R1, procedimentos paliativos, esofagogastrectomias completas e operações de emergência. Resultados: Foi incluído um total de 284 pacientes; da amostra 65,4% eram homens, com média de idade de 64,5 anos, 75% eram cânceres avançados, 72,5% necessitaram de gastrectomia total e 30 coletas de linfonodos. A morbimortalidade cirúrgica foi de 17,2% e 1,7%. Sobrevida em cinco anos foi de 56,9%. O índice N +/T pôde predizer a sobrevida em longo prazo em todos os subgrupos (p<0,0001), embora tivesse previsão confiável em GC precoce (p=0,005), GC avançado (p<0,0001), célula GC de anel de sinete (p< 0,0001), GC proximal (p<0,0001) e GC distal (p<0,0001). As curvas ROC N +/T, LNR e T apresentaram áreas abaixo da curva de 0,789, 0,786 e 0,790, respectivamente, sem diferença estatística significativa (p=0,96 ). Conclusão: O índice N +/T é um quociente confiável no prognóstico na avaliação de pacientes com adenocarcinoma gástrico que foram ressecados com intenção curativa.

ABSTRACT Background: The identification of prognostic factors of gastric cancer (GC) has allowed to predict the evolution of patients. Aim: Assess the reliability of the lymphoparietal index in the prediction of long-term survival in GC treated with curative intent. Method: Prospective study of the Universidad de Chile Clinical Hospital, between May 2004 and May 2012. Included all gastric cancer surgeries with curative intent. Exclusion criteria were: gastrectomies due to benign lesions, stage 4 cancers, R1 resections, palliative procedures, complete esophagogastrectomies and emergency surgeries. Results: A total of 284 patients were included; of the sample 65.4% were male,mean age of 64.5 years,75% were advanced cancers, 72.5% required a total gastrectomy, 30 lymph nodes harvest. Surgical morbidity and mortality were 17.2% and 1.7%. 5-year survival was 56.9%. The N+/T index could predict long-term survival in all de subgrups (p<0.0001), although had a reliable prediction in early GC (p=0.005), advanced GC (p<0.0001), signet ring cell GC (p<0.0001), proximal GC (p<0.0001) and distal GC (p<0.0001). The ROC curves N+/T index, LNR and T classification presented areas below the curve of 0.789, 0.786 and 0,790 respectively, without a significant statistical difference (p=0.96). Conclusion: The N+/T index is a reliable quotient in the prognostic evaluation of gastric adenocarcinoma patients who have been resected with curative intent.

Background Antimicrobial resistance is a worldwide problem. In patients requiring emergency surgery, antibiotics are an important assistance additional to surgical intervention. Objective Analize peritoneal fluid cultures obtaines from patients who underwent emergency surgery. Methods A prospective cohort of emergency abdominal surgical patients were enrolled. Peritoneal fluid cultures were taken and processed according to standarized technique. Results A 39.4% of positive cultures was found. E. coli was the most common bacteria identified. Five positive cultures for P. aeruginosa stand out. E. coli had 25% resistance to ampicillin/sulbactam and 19% for quinolones. Conclusion Resistance found was lower than international reports, but still noteworthy. Knowledge of local bacteria profile and antimicrobial resistance is important for local antibiotic hospital policy.

Resumen Introducción La resistencia a antibióticos es un problema mundial. En los pacientes que requieren cirugía de urgencia, los antibióticos son un apoyo importante concomitante al acto quirúrgico. Objetivo Analizar los cultivos de líquido peritoneal obtenidos de pacientes operados por patología quirúrgica abdominal de urgencia. Materiales y Métodos Se realiza una cohorte prospectiva de los pacientes operados de urgencia. Se tomó cultivo de líquido peritoneal y se procesó según técnica estandarizada. Resultados Se encontró un 39,4% de cultivos positivos. E. coli fue el germen más frecuente. Destacan 5 cultivos positivos para P. aeruginosa. Existe un 25% de resistencia a ampicilina/sulbactam y 19% a quinolonas para E. coli. Conclusión La resistencia encontrada fue menor a lo reportado en la literatura, pero aún destacable. El conocimiento del perfil de bacterias y sus resistencias a antimicrobianos son importantes para las políticas hospitalarias locales de uso racional de antibióticos.

Introduction: Transanal total mesorectal excision is a hybrid approach that combines the use of a conventional laparoscopic and a transanal platform. Objectives: To conduct an analysis of selected cases with medium and lower rectal cancer, were a combined transanal approach was used and description of the surgical technique. Materials and methods: Prospective series of patients diagnosed with middle and lower third rectal cancer with mesorectal resection assisted by endoanal single port, between October 2012 and December 2015 at University of Chile Clinical Hospital. Descriptive statistics were used for data analysis. Results: A total of 29 patients underwent surgery for middle and lower rectal cancer using a transanal single port. Gender distribution was 22 male and 7 female patients, with a mean age of 55.5 years and a mean BMI of 26.4. The mean distance from the anal margin was 4.8 cm. All patients received neoadjuvant therapy. The surgeries performed were 17 Ta-TME (58.6%) and 12 Ta-TME with intersphincteric approach (41.4%). The colo-anal anastomosis was hand sewn in 15 patients (51.7%), and stapled in 14 (48.3%). The laparoscopic approach was used in 26 patients and the open approach in 3, with 4 conversions (15.4%). The mean operative time was 282 min. The mean hospital stay was 9 days. Conclusion: The endoanal single port appears as a useful tool in total mesorectal dissection for its safety and feasibility. We believe we need randomized prospective studies, where comparison of oncological and functional long-term results is relevant.

Introducción: La resección total del mesorrecto por vía transanal es un abordaje híbrido que combina el uso de una plataforma transanal y laparoscopia convencional. Objetivos: Realizar el análisis de casos seleccionados con cáncer de recto medio e inferior en los cuales se utilizó un abordaje transanal combinado para su resolución y la descripción de la técnica quirúrgica. Materiales y métodos. Corresponde a una serie prospectiva de pacientes con diagnóstico de cáncer de recto de tercio medio e inferior con resección mesorrectal asistida por monopuerto endoanal entre octubre de 2012 y diciembre de 2015, en Hospital Clínico Universidad de Chile. Se utilizó estadística descriptiva para el análisis de los datos. Resultados: Fueron sometidos a cirugía por cáncer de recto medio e inferior un total de 29 pacientes utilizando monopuerto transanal. De estos, 22 fueron de sexo masculino y 7 de sexo femenino, con edad promedio de 55,5 años e IMC de 26,4. La distancia media al margen anal fue 4,8 cm. Todos recibieron neoadyuvancia. Se realizaron 17 Ta-TME (58,6%) y 12 Ta-TME con abordaje interesfintérico (41,4%). La anastomosis fue coloanal manual en 15 pacientes (51,7%) y grapada en 14 (48,3%). El abordaje laparoscópico se utilizó en 26 pacientes y el abierto en 3, registrando 4 conversiones (15,4%). El tiempo operatorio promedio fue de 282 min. La estadía hospitalaria media fue de 9 días. Conclusión: El monopuerto endoanal aparece como una herramienta útil en la disección total del mesorrecto por su seguridad y factibilidad. Creemos que es necesaria la realización de trabajos prospectivos aleatorizados, donde es relevante la comparación de resultados oncológicos y funcionales a largo plazo.

Introduction: The treatment of rectal cancer has progressed in the past decade. Nowadays, it's feasible to provide sphincter sparing surgery with low colorectal anastomosis or coloanal anastomosis. This has determined that many patients develop intestinal dysfunctions that can become severe, grouping a number of disorders known as low anterior resection syndrome. Objective: To perform a cultural adaptation of the version 1.0 questionnaire about bowel function or Low Resection Syndrome Score (LARS Score) in neutral Spanish, making a translation, comparing translations, back translation and pilot test. Results: The results of the pilot test showed that the population surveyed understood the instrument, so that no further modifications were made. Conclusion: We now have an adapted version of the LARS questionnaire for use in Chile, which can undergo validation processes to establish the psychometric characteristics for use in patients with rectal cancer surgery.

Introducción: El tratamiento en el cáncer de recto ha progresado en la última década. Hoy es factible ofrecer una cirugía con preservación de esfínteres, realizando anastomosis colorrectales bajas o anastomosis coloanales. Esto ha determinado que muchos pacientes desarrollen disfunción intestinal que puede llegar a ser severa, agrupando una serie de alteraciones que se conocen como síndrome de resección anterior baja. Objetivo: Efectuar una adaptación cultural de la versión 1.0 en español neutro del cuestionario acerca de la función intestinal o Low Anterior Resection Syndrome Score (LARS Score), efectuando traducción, comparación de traducciones, traducción inversa y prueba piloto. Resultados: Los resultados obtenidos de la prueba piloto revelan que la población encuestada logró comprender el instrumento, por lo que no se realizaron modificaciones posteriores. Conclusión: Se cuenta con una versión adaptada del cuestionario LARS para ser usada en Chile, la cual puede someterse a procesos de validación y establecer las características psicométricas para ser usada en pacientes con cáncer de recto operados.

Background: The molecular testing of KRAS mutation status in metastatic colorectal cancer patients is mandatory to identify patients eligible for anti-epidermal growth factor receptor monoclonal antibody therapy. Aim: To report the frequency of KRAS gene mutations in Chilean patients with colorectal cancer (CRC). Material and Methods: A cohort of 262 Chilean patients with CRC aged 26 to 90 years (53% males), was studied. KRAS mutation status was analyzed by real-time polymerase chain reaction and correlated with clinicopathological data. Results: Ninety-eight patients (37%) were positive for KRAS mutations. G12D was the most common mutation with a frequency of 36.7%, followed by G12V (25.5%), G13D (17.3%), G12A (7.1%), G12C (6.1%), G12S (5.1%) and G12R (2%). The frequency of the mutation in left, right colon and rectal tumors was 37.8, 32.6 and 44.9%, respectively. Among tumors with mutations, 86.7% were well or moderately differentiated tumors and the rest were poorly differentiated. No significant associations between KRAS gene mutations and other clinicopathological features of the tumor were observed. Conclusions: The frequencies of KRAS mutations reported in this study are similar to frequencies reported for European and North-American populations, lower than in a Spanish study and higher than in a Peruvian study.