Resumen El bad split es un término clínico que refiere a una fractura no planificada que ocurre al momento de realizar una osteotomía sagital de rama mandibular (OSRM). Afecta aproximadamente al 2,3% de los pacientes y se han descrito factores de riesgo tales como la presencia de terceros molares mandibulares, edad avanzada al momento de la cirugía, técnica de osteotomía inadecuada, entre otros. Se recomienda efectuar manio-bras preventivas para evitar la aparición de patrones de fractura no deseados al realizar la OSRM. Sin embargo, al momento de pesquisar un bad split, éste debe ser tratado por un equipo capacitado y de manera oportuna para evitar retardo en la consolidación, infecciones y secuestros óseos que puedan comprometer los resultados de la cirugía. En este artículo se presenta el manejo de un caso clínico de bad split bilateral intraoperatorio por el Servicio de Cirugía Maxilofacial del Hospital San José, enfatizando su tratamiento quirúrgico.

Abstract Bad Split is a clinical term referring to an unplanned fracture that occurs during the bilateral sagittal split osteotomy (BSSO). It affects approximately 2,3% of the patients undergoing orthognathic surgery and several risk factors have been described such as the presence of mandibular third molars, advanced age at the moment of orthognathic surgery, inadequate osteotomy technique, etc. Preventive maneuvers are recommended in order to avoid the appearance of undesired fracture patterns during BSSO. However, if a bad split is detected it must be managed and treated by a qualified team to avoid further complications such as delayed bone consolidation, bone infection and necrosis. In this article we present the management of a case of bilateral bad split by the Maxillofacial Surgery Service of Hospital San José, emphasizing on its surgical treatment.

Introduction: There are different prognostic scores to determine the probability of death in burned patients. The Garces Index (GI) used in Chile is not accepted worldwide. Aim: We decided to evaluate the correlation between IG and Abbreviated Burn Severity Index (ABSI), which is widely used. Materials and Method: Cross-sectional analytical and descriptive study of burned patients uploaded to the online platform “National Burns Registry” and then admitted to our center between July 2017 and July 2018. Pearson's correlation coefficient between IG and ABSI was calculated. Both variables were normalized to be able to make them comparable and the agreement between them was calculated with Lin's correlation coefficient. With logistic regression analysis, the associated probability of death was calculated for both variables and areas of the ROC curves of both scores were compared. Results: Of 141 patients, 15 died during hospitalization, with a mean GI 104 ± 49 and ABSI 7 ± 2. Pearson's correlation coefficient between GI and ABSI showed a very high correlation with a value of 0.928. Lin's correlation coefficient gave moderate agreement with a value of 0.93. When checking which of the two scores best predicts the probability of death through sensitivity and specificity analysis, the ROC curve covers more area in IG (0.82 vs 0.83) without being statistically significant. Conclusions: Both scores, IG and ABSI, are very similar when it comes to predicting the probability of death, which is why they are comparable at the time of sharing the results in scientific studies.

Resumen Introducción: Existen distintos scores pronósticos para determinar probabilidad de muerte en pacientes quemados. El Índice de Garcés (IG) utilizado en Chile, no es aceptado mundialmente. Objetivo: Decidimos evaluar la correlación entre IG y Abbreviated Burn Severity Index (ABSI), de uso generalizado. Materiales y Método Estudio descriptivo analítico transversal de pacientes quemados subidos a la plataforma online “Registro Nacional de Quemados” y luego ingresados a nuestro centro entre julio de 2017 y julio de 2018. Se calculó coeficiente de correlación de Pearson entre IG y ABSI. Se normalizan ambas variables para hacerlas comparables y se calculó concordancia entre estas con coeficiente de correlación de Lin. Con análisis de regresión logística se calculó probabilidad de fallecer asociada para ambas variables y se compararon áreas de las curvas ROC de ambos scores. Resultados: De 141 pacientes, 15 fallecieron durante hospitalización, con medias de IG de 104 ± 49 puntos y ABSI 7 ± 2. El coeficiente de correlación de Pearson entre IG y ABSI demostró ser muy alto con un valor de 0,928. El coeficiente de correlación de Lin entregó concordancia moderada con un valor de 0,93. Al comprobar cuál de las dos puntuaciones predice mejor la probabilidad de muerte mediante análisis de sensibilidad y especificidad, la curva ROC cubre más área en IG (0,82 vs. 0,83), sin ser estadísticamente significativo. Conclusiones: Ambos índices, IG y ABSI, son muy similares para predecir la probabilidad de muerte, por lo cual son equiparables a la hora de compartir resultados de estudios científicos.

Introduction: In 2017, an online notification register, the National Burn Registry, was incorporated into the referral flow of burned patients in Chile. Aim: Through the information obtained from this platform, we describe the epidemiology of burns in Chile, and identify variables that could explain failed transfers to our burn unit. Materials and Method: Cases uploaded to this platform between July 2017 - July 2018 were analyzed. We characterize the global population and relevant variables were compared between the group of patients that failed to be transferred to the burn unit and the ones who were successfully transferred. Results: 319 patients were analyzed, 66% men, average age 51 years, BMI of 27 and 47% with previous illnesses. Fire was the main cause of burn injury. Smoke inhalation injury was observed for 31%. 107 patients failed to reach to our burn center. Transferred patients rated higher in comorbidity, severity index, total burned body surface and surgical debridement at base hospital. The group of not transferred patients rated higher in inhalation injury. Overall mortality was 20.4%. Mortality was higher in non-transferred patients (33.6% versus 13.7%; p < 0.001). Conclusions: Aside from facilitating the flow of burned patients and resources saving, a noble use of this platform has been to serve as a source of epidemiological information and implementation of public policies, which can be taken as an example by other developing countries. Also, being transferred is a protective factor for death from burn injuries.

Resumen Introducción: En el año 2017 se incorporó un registro de notificación en línea (Registro Nacional de Quemados) al flujo de derivación de pacientes quemados en Chile. Objetivo: A partir de la información obtenida de esta plataforma, se describe la epidemiología de las quemaduras y las variables que podrían explicar los traslados fallidos a nuestra unidad de quemados. Materiales y Método: Se analizaron los casos subidos a esta plataforma entre julio de 2017 y julio de 2018. Se caracterizó la población global y comparó variables relevantes entre el grupo de pacientes no trasladados a nuestra unidad y los que fueron trasladados con éxito. Resultados: Se analizaron 319 pacientes, 66% hombres, edad promedio 51 años, IMC de 27% y 47% con enfermedades previas. El fuego fue la principal causa de quemaduras. Se observó un 31% de injuria inhaladora. 107 pacientes no se trasladaron a nuestro centro de quemados. Los pacientes trasladados puntuaron más alto en comorbilidad, índice de gravedad, superficie corporal total quemada y aseo quirúrgico en el hospital base. El grupo de pacientes no trasladados puntuó más alto en injuria inhalatoria. La mortalidad global fue 20,4%. La mortalidad fue mayor en pacientes no trasladados (33,6% versus 13,7%; p < 0,001). Conclusiones: Además de facilitar el flujo de pacientes y ahorrar recursos, un uso noble de esta plataforma es ser fuente de información epidemiológica y de implementación de políticas públicas, lo cual puede ser tomado como ejemplo por otros países en vías de desarrollo. Además, se demuestra que ser trasladado constituye un factor protector de muerte por quemaduras.

Resumo O lago Llanquihue está incluído nos chamados lagos araucana ou Nord Patagônia localizado entre 38-41° S. Estes lagos são caracterizados pela condicao oligo-mesotrofica debido a intervencao humana, com aumento da carga de nutrientes provenientes de industrias y areas urbanas com efeitos sobre as assembleias zooplantonicas sao observadas, com aumento acentuado de dafnideos. O objetivo do presente estudo é analisar o estado trófico a abundancia relative do zooplancton em diferentes compartimentos do lago Llanquihue. Foram encontradas associações diretas entre clorofila a com percentual de dafinídeos, nitrogênio total dissolvido com fósforo solúvel reativo molares razao molar nitrogênio / fósforo com percentual de ciclopóides, e uma relação inversa entre percentuais de dafinídeos e calanóides porcentagens. A ocorrência de três tipos de assembleias de microcrustáceos e as condições ambientais fora: a primeira com alta porcentais de calanóides, baixo número de espécies e baixa clorofila e a nutrientes, uma segunda com concentracoes moderadas de clorofila e nutrientes percentual moderado de daphnideos e alto número de espécies; e uma terceiro local com alta concentração de clorofila e nutrientes, alta abundância dafinídeos e número elevado de espécies. Resultados similares com aumento de dafnideos em condicoes mesotroficas também foram observados para lagos da Argentina e Nova Zelândia do sul.

Abstract The Llanquihue lake is included in the called Araucanian or Nord Patagonian lakes located between 38-41° S. These lakes are characterized by their oligo-mesotrophic status due to human intervention which takes to the increase in nutrients inputs from industries and towns. Effects on zooplankton assemblages are observed with marked increase of daphnids abundance. The aim of the present study is to analyze the trophic status and zooplankton relative abundance in different bays of Llanquihue lake. It was found direct associations between chlorophyll a with daphnids percentage, total dissolved nitrogen with reactive soluble phosphorus nitrogen/phosphorus molar radio with cyclopoids percentage, and an inverse relation between daphnids and calanoids percentages. The occurrence of three kinds of microcrustacean assemblages and environmental conditions was evidenced: the first one with high calanoids percentage, low species number and low chlorophyll and nutrients concentration, a second with moderate chlorophyll and nutrients concentration and moderate daphnids percentage; high species number and a third site with high chlorophyll and nutrients concentration, high daphnids percentage and high species number. Daphnids increase under mesotrophic status, agree with similar results observed for southern Argentinean and New Zealand lakes.

The Sebaceous Carcinoma (SC) is an uncommon malignant tumor formed by cells that show differentiation toward sebaceous epithelium. It usually occurs in women of average at 70 years of age. We report a case of a 69 years old female with a family history of multiples cancer, breast cancer and the emergence of multiple sebaceous adenomas and carcinomas, features consistent with Syndrome Muir Torre (SMT). The 75% of the SC are located in the ocular region and the 25% rest presents extraocular location. The eye location is characterized by aggressive behavior, with direct extension and high potential for regional and distant metastases. Extraocular are generally less aggressive tumors and are located mainly in the head and neck. The pathogenesis is unclear, but chronic inflammatory processes, ultraviolet radiation and radiation will favor its development. The SC is a versatile tumor that presents with different clinical and histological different growth patterns, which retard the definitive diagnosis. SC is one of the cutaneous diagnostic markers of SMT, which is a genetic disease associated with visceral neoplasms. They are carefully assessed, performing a proper personal and family cancer history. The treatment of choice is the surgery with wide margins.

El Carcinoma Sebáceo (CS) es una neoplasia maligna, poco frecuente, formada por células que muestran una diferenciación hacia el epitelio sebáceo. Generalmente, se presenta en promedio a los 70 años de edad, es más frecuente en mujeres y principalmente en raza asiática. Presentamos el caso de una paciente de sexo femenino de 69 años, con antecedentes familiares de múltiples cánceres, cáncer de mama y la aparición de numerosos adenomas y carcinomas sebáceos, cuadro compatible con un Síndrome de Muir-Torre (SMT). El 75% de los CS se localizan en la región ocular y el 25% es de ubicación extra-ocular. El de ubicación ocular, se caracteriza por un comportamiento agresivo, con diseminación directa y alto potencial de metástasis regional y a distancia. Los tumores extraoculares generalmente son menos agresivos y se localizan principalmente en cabeza y cuello. La patogénesis es incierta, pero los procesos inflamatorios crónicos, la radiación ultravioleta y la radioterapia favorecerán su desarrollo. El CS es un tumor versátil, que se presenta con diferentes aspectos clínicos y distintos patrones histológicos de crecimiento, que retardan el diagnóstico definitivo. El CS es uno de los marcadores cutáneos diagnósticos del SMT, que es una enfermedad genética asociada a neoplasias viscerales. Por lo tanto, los pacientes con CS deben ser cuidadosamente valorados, realizándose una historia oncológica personal y familiar adecuada. El tratamiento de elección es la cirugía con márgenes amplios.

Subungual keratoacanthoma is a rare and uncommon variant of keratoacanthoma. It shows a locally aggressive behavior, and spontaneous regression is infrequently. The tumour usually occurs on the fifth decade of male caucasian patients, with predilection for the first three fingers of the hand. The cause is still unknown, and occurs more frequently in patients with incontinentia pigmenti and is considered a late manifestation of the disease. We report a patient’s case with incontinentia pigmenti, who has a lesion in her right thumb, compatible with a subungual keratoacanthoma. This tumour is known for being difficult to diagnose, so it must be based on correlation of clinical, radiological and histopathological findings. It is crucial to make the differential diagnosis with subungual invasive squamous cell carcinoma, as they differ in treatment, since the latter has an aggressive behavior and needs radical treatment, while the handling of the keratoacanthoma might be conservative.

El queratoacantoma subungueal es una variante infrecuente, no involutiva y localmente destructiva de queratoacantoma, se presenta con cierta predilección en los tres primeros dedos de la mano y con mayor frecuencia en pacientes caucásicos varones, generalmente en la quinta década de la vida. La causa aún es desconocida y se observa con mayor frecuencia en pacientes con incontinencia pigmenti, como una manifestación tardía de ésta. Comunicamos el caso de una paciente con incontinencia pigmenti, quien presenta una lesión en pulgar derecho compatible con un queratoacantoma subungueal. Este tumor se caracteriza por su difícil diagnóstico, por lo que éste debe basarse en la correlación de los hallazgos clínicos, radiológicos e histopatológicos. Es importante realizar el diagnóstico diferencial con el carcinoma escamoso invasor subungueal, ya que, difieren en el tratamiento, siendo el segundo más agresivo y merecedor de un tratamiento radical, a diferencia del queratoacantoma que puede tener un manejo más conservador, a pesar que es solo una variante clínica del carcinoma espinocelular, tal como lo es la enfermedad de Bowen o el carcinoma verrugoso, para nombrar solo a dos.

Lichen sclerosus et atrophicus (ALE) of the penis, also known as balanitis xerotica obliterans (BXO) is a chronic inflammatory disease of the penis that can occur at any age. The inflammation leads to the formation of hypochromic plaques, most commonly in the foreskin or on the glans. BXO can cause phimosis, pruritus, pain, dysuria, urinary restriction, dyspareunia, and significant sexual dysfunction. We present a case of BXO associated to vitiligo in a 78 years old patient, who consulted for dyspareunia. It was referred to urologist for surgical resolution, where circumcision was performed with biopsy compatible with BXO. In recent years studies have found that it could exists, an autoimmune ethiopathogenic factor of the disease. The topical use of high power corticosteroids is still the first choice and surgery remains a good treatment in severe cases (ex. phimosis) or those who do not respond to steroids.

El liquen escleroso y atrófico (LE y A) del pene, también conocido como balanitis xerótica obliterante (BXO), es una enfermedad inflamatoria crónica del pene que puede ocurrir a cualquier edad. La inflamación conduce a la formación de placas hipocrómicas, más comúnmente en el prepucio o en el glande. En general puede causar fimosis, prurito, dolor por las fisuras, disuria, restricción de la micción, dispareunia y disfunción sexual significativa. Comunicamos un caso de BXO asociado a vitiligo en un paciente de 78 años, quien consultó por dispareunia. Fue derivado a Urología para resolución quirúrgica, donde se realizó una postectomía, cuyo estudio era compatible con una BXO. Muchos hallazgos obtenidos en los últimos años apuntan cada vez más, hacia un origen autoinmune de esta enfermedad. El uso de corticoides tópicos de alta potencia es todavía la mejor terapéutica, siendo la cirugía un buen tratamiento en casos muy severos, con fimosis importante o aquellos que no responden al uso de corticoides o inhibidores de la calcineurina, como el tacrolimus o pimecrolimus.

In Chile there are strong societal demands. However, there exists a lack of scholarly research regarding possible sources of fiscal revenue for social investment. This paper proposes taxes on multinational mining companies that would allow to transfer to the state their above-normal returns. Additionally, this work estimates the value of these profits. Both estimates use the net present value method to represent the profitability of an average copper mining project. The results were tested using varying copper prices and other model parameters.

En Chile existen fuertes demandas sociales. Sin embargo, existe falta de investigación académica con respecto a la cuantía de posibles fuentes de mayores ingresos fiscales. En este trabajo se propone un nivel de impuesto a las compañías mineras multinacionales que permitiría traspasar al Estado sus ganancias sobre-normales. Además, se estima el valor de estos beneficios. Ambas estimaciones utilizan el método de valor presente neto para representar la rentabilidad de un proyecto de minería de cobre de tamaño medio. Los resultados se analizaron utilizando diferentes precios del cobre y de otros parámetros del modelo.

No Chile existem fortes demandas sociais. No entanto, falta de pesquisa acadêmica sobre a quantidade de potenciais fontes para um aumento das receitas fiscais. Neste trabalho é proposto um nível de imposto para as empresas de mineração multinacionais que permitiria transferir para o Estado seus ganhos além de um patamar normal. Além disso, é estimado o valor desses benefícios. Ambas as estimativas usam o método do valor presente líquido para representar a rentabilidade de um projeto de mineração de cobre de tamanho médio. Os resultados foram analisados utilizando diferentes preços do cobre e de outros parâmetros do modelo.

Karwinskia humboldtiana (Kh) is a poisonous shrub causing a number of accidental intoxications in humans. In previous studies in our laboratory, we reported an increased number of mast cells present in peripheral nerve of Kh intoxicated rats. This finding has not been reported in other organs of intoxicated animals. For this reason, in the present study we searched for mast cells in several organs, identifying mast cell subpopulations on the basis of different histochemical reactivity of their secretory granules. Thus the objective of the present study was to evaluate the presence of mast cells in organs other than peripheral nerve and, to distinguish mast cells by their granule content, applying histochemical reactions. 32 Wistar rats were divided into 4 groups (n=8). For each group, 5 rats were intoxicated with Kh and 3 received water only as a control.Intoxicated rats received 3.5 g/ Kg body weight of dry powder of Kh fruits, fractionated in 5 doses as follows 1.5, 0.5, 0.5, 0.5, 05 on days 0, 3,7,10,14 respectively. Control rats received water only. Each group was killed at different times during paralysis evolution. Samples of liver, kidney, lung and brain, were obtained and processed by routine technique until paraffin embedding. Sections were obtained and stained with toluidine blue, PAS, alcian blue/PAS and alcian blue/safranin. Mast cells infiltrates were observed in peripheral nerve and lung. Mast cells were counted. An increasing number of mast cells were recorded as well as variations in the histochemical pattern of their granules for each organ. These findings suggest a role for mast cells and their secretions in the intoxication with mature fruit of Kh.

Karwinskia humboldtiana (Kh) es un arbusto venenoso responsable de numerosos casos de intoxicación accidental en humanos. En estudios previos en nuestro laboratorio reportamos un incremento de células cebadas en nervio periférico (NP) durante la intoxicación con Kh, este hallazgo no ha sido reportado previamente en otros órganos durante esta intoxicación por lo que en el presente estudio buscamos la presencia de estas células en otros órganos, además de distinguir subpoblaciones de células cebadas mediante reacciones histoquímicas para la identificación de los gránulos de secreción. El objetivo de este estudio fue evaluar la presencia de células cebadas en órganos distintos al NP y diferenciar histoquímicamente la composición de sus gránulos. Se utilizaron 32 ratas Wistar, se dividieron en cuatro grupos (n= 8) en donde 5 ratas de cada grupo fueron intoxicadas y 3 fueron control no intoxicadas. A las ratas intoxicadas se les administraron por vía oral 3,5 g/kg del fruto seco y molido de Kh fraccionados en 5 dosis de 1,5; 0,5, 0,5; 0,5 y 0,5 g/kg los días 0, 3, 7, 10 y 14 respectivamente. Las ratas control solo recibieron agua. Cada grupo fue sacrificado a diferentes tiempos según la evolución de la parálisis. Se obtuvieron muestras de Hígado, Riñón, Pulmón y SNP, se procesaron hasta obtener bloques de parafina, se obtuvieron cortes y se tiñeron con azul de toluidina, PAS, Azul alciano/PAS y Azul alciano/Safranina. Se identificó la presencia de células cebadas en NP y pulmón con la tinción de azul de toluidina y se realizo un estudio morfométrico observando un incremento progresivo del número de células cebadas por grupo así como variaciones histoquímicas en sus gránulos en cada etapa y órgano analizado, lo que sugiere la participación de las células cebadas y sus secreciones en cada una de las etapas de la intoxicación crónica con el fruto maduro de Kh.

Estudiamos tres parcelas de una hectárea cada una incluyendo todos los árboles con diámetro a la altura del pecho de 10 cm o más en el ecosistema estacional del Refugio Los Volcanes (1.000- 1.400 m de altitud), situado en el centro de Bolivia. Las parcelas incluyeron variantes locales de bosques deciduos, semideciduos y siempreverdes. Encontramos un total de 115 especies y 43 familias. La parcela más diversa fue la semidecidua con 70 especies, 56 géneros y 31 familias; con bosque siempreverde tuvo valores de diversidad similares o ligeramente más bajos (63 especies, 49 géneros, 31 familias); mientras la que presenta bosque deciduo tuvo valores mucho más bajos (44 especies, 38 géneros y 21 familias) y compartía sólo 19 y 15 especies con las parcelas en el bosque semideciduo y siempreverde, respectivamente. Entre un 34% y 50% de las especies en las parcelas eran localmente raras con sólo uno o dos individuos por parcela. Por otro lado, un alto porcentaje del número total de individuos y del área basal era contribuido por unas pocas especies dominantes en cada parcela. Pachystroma longifolium (Nees) I.M. Johnst. (Euphorbiaceae) fue la única especie que estaba entre las tres especies más dominantes en cada una de las tres parcelas. Leguminosae fue la familia más importante en las parcelas de bosque deciduo y semideciduo. El bosque siempreverde contenía un conjunto de familias dominantes distintas a las otras parcelas. Los valores de riqueza de especies fueron similares a otros estudios de inventarios forestales en ecosistemas estacionales comparables realizados en Bolivia. La composición de especies y familias por otro lado, fue diferente, exceptuando el hecho bien conocido que Leguminosae es la familia dominante en bosques estacionalmente secos del Neotrópico. Fitogeográficamente, la flora arbórea de las parcelas de Los Volcanes es heterogénea, estando compuesta de elementos de bosques estacionalmente secos así como de los bosques tropicales húmedos.

We studied trees with a diameter at breast height ≥ 10 cm on three one-hectare plots in the Refugio Los Volcanes seasonal forests (1,000-1,400 m elevation), located in the Andean foothills of central Bolivia. The plots included local variants of deciduous, semi-deciduous and evergreen forest vegetation. We recorded a total of 115 species and 43 families. The most diverse plot was the semi-deciduous forest plot with 70 species, 56 genera and 31 families, whereas the evergreen forest plot had slightly lower richness values (63 species, 49 genera, 31 families). The deciduous forest plot had much lower numbers (44 species, 38 genera and 21 families) and shared only 19 and 15 species with the semi-deciduous and evergreen forest plots, respectively. Between 34% and 50% of the species in the study plots were locally rare species, i.e., species with only one or two individuals per plot. On the other hand, a high percentage of the total number of individuals and basal area was contributed by a few dominant species in each plot. Pachystroma longifolium (Nees) I.M. Johnst. (Euphorbiaceae) was the only species among the three most important species in each of the three plots. Leguminosae was the most important family in the deciduous and semi-deciduous plots. The evergreen forest plot contained different dominant families compared to the other two plots. The species richness values we found in this study were similar to other tree inventories in comparable seasonal forest ecosystems in Bolivia. Species and familial composition, however, were contrastingly different, except for the well-known fact that Leguminosae is the numerically most important family in seasonally dry Neotropical forest ecosystems. Phytogeographically, the tree fora of Los Volcanes is heterogeneous, being composed of elements belonging to seasonal forests as well as to humid tropical forests.

Objective: to evaluate our results about local failure, total recurrence and survival. Method: twenty-one patients underwent a complete local transanal excision for low rectal cancer in our institution during an 18-year period (1985-2003). Preoperative staging included clinical, endoscopic, CT, EUSR, and histopathological findings; pathological specimens were 4 T1, 13 T2 and 4 T3 tumors. None of the T1 patients received another treatment; 6 out of 13 T2 and all of T3 cases were treated with chemoradiotherapy. None of the latter underwent radical surgery. Results: follow-up (median 74 months) proved 23.8% for total recurrence and 19.0% for local failure (out of all 3 T2 cases only one received chemoradiotherapy, and one T3 received adjuvant treatment). Five-year survival is 95.2%. Conclusions: this experience allows us to assert that local excision is a good choice in well-selected low rectal cancer patients; for T2 tumors chemoradiotherapy is necessary; in T3 patients radical surgery must be prompt.

Objetivo: evaluar nuestros Resultados alejados en términos de recidiva local, rescate y sobrevida libre de enfermedad. Método: veintiún pacientes con un cáncer de recto bajo fueron sometidos a una resección transanal completa en un periodo de 18 años (1985-2003). La estadificación preoperatoria incluyó hallazgos clínicos y endoscópicos, estudios por imágenes e histopatológicos. Los especímenes resecados correspondieron a 4 tumores T1, 13 T2 y 4 T3. Los 4 pacientes T1 sólo fueron tratados con cirugía; 6 de los 13 T2 y todos los T3 recibieron quimiorradioterapia postoperatoria. Ninguno de ellos recibió una cirugía radical secuencial. Resultados: el seguimiento (media 75 meses) registró 5 casos (23,8%) de recidiva total y 4 (19%) con falla local (3 T2 de los cuales sólo uno había recibido terapia coadyuvante y un T3 también tratado con quimiorradioterapia). Los cuatro pacientes con recidiva local accedieron a cirugía de rescate, una amputación abdominoperineal en dos casos y a una re-resección local en los otros. Dos de ellos volvieron a recidivar. La sobrevida a 5 años fue de 95,2%, y la sobrevida libre de enfermedad en el mismo periodo alcanzó a un 90,4%. En el periodo de observación hasta agosto de 2006 hay dos pacientes que fallecieron diseminados, y sólo un paciente vivo está recidivado. Conclusiones: esta experiencia confirma que la resección local transanal para cáncer de recto bajo es una buena alternativa en pacientes adecuadamente seleccionados. En tumores T2, la quimiorradioterapia adyuvante será necesaria; en tumores T3, la cirugía radical de rescate debería ser realizada oportunamente.

Background: First degree relatives of patients with colorectal carcinoma are at a higher risk of having the disease than the general population. Therefore, they should be subjected to screening colonoscopy. Aim: To assess the effectiveness of colonoscopy among first degree relatives of patients with colorectal carcinoma. Material and methods: A free colonoscopy was offered to first degree relatives of patients operated on for colorectal cancer between 1998 and 2000. As inclusion criteria, subjects had to be asymptomatic, older than 40 years or less than 10 years younger than the index case. Each subject was contacted twice, inviting him/her to have a colonoscopy performed. Results: Two hundred forty three relatives were contacted for the study and in 76, a colonoscopy was performed. Among the latter, a neoplasm was found in 13 (17%): One adenocarcinoma and 12 adenomas. Three of these lesions were located in the right colon. The main reason given by the 176 subjects that did not agree to have a colonoscopy was lack of interest. Conclusions: Screening colonoscopy is effective to detect adenoma and adenocarcinomaamong first degree relatives of patients with colorectal carcinoma, however only 31% of all potential relatives agreed to undergo a colonoscopy (Rev Méd Chile 2006; 134: 997-1001)

Background: Among colorectal cancer hereditary variants, two syndromes show a predisposition to the disease based on germline mutations: Familial Adenomatous Polyposis (FAP) and Hereditary Nonpolyposis Colorectal Cancer (HNPCC). Aim: To screen mutations in FAP and HNPCC families in Chile. Materials and Methods: Two FAP and one HNPCC families were studied. The APC gene (for FAP patients) and the MLH1 gene (for HNPCC patients), were screened for mutations on genomic DNA. The molecular analysis was performed through polymerase chain reaction, Single Strand Conformer Polymorphism (SSCP) and DNA sequencing. Mutations were defined as changes in the DNA sequence leading into a stop codon and a truncated protein. Results: In the two FAP families the analysis revealed a mutation consisting in the deletion of five nucleotides named c.3927_3931delAAAGA. The genetic study of the HNPCC family demonstrated the insertion of one adenine in codon 168 of exon 6, named c.504insA. Discussion: Germ-line mutations were identified in the three families. The relevance of these studies in a better knowledge of cancer susceptibility, and the possibility of identifying in relatives in risk by molecular diagnosis

Background: To reduce the mortality associated to Familial Adenomatous Polyposis (FAP), screening of close relatives of patients with the disease is crucial. Aim: To analyze the results of the surgical treatment of patients with FAP, and to evaluate the family screening. Patients and Methods: Clinical records of patients operated in our institution since 1977, were reviewed analyzing surgical and pathological results, and follow up. In their family members, we evaluated and analyzed the performance of screening tests, former surgeries, history of disease-related cancer and mortality, all due to FAP. Results: Between January 1977 and August 2002, 15 patients were operated on. Of these, only 33% consulted on the setting of a familial screening. A proctocolectomy and terminal ileostomy was performed in 27% of patients; 20% had a proctocolectomy and ileal pouch, and 53% underwent a total colectomy with ileo-rectal anastomosis. Morbidity and mortality were 7% and 0%, respectively. Twenty percent had a colorectal cancer. During a median of 68 months follow-up, the disease-related survival was 92%; no cancer of the rectal stump was detected. Of the 122 family members identified, only 33% with clear indication of screening underwent a colonoscopy. Twenty-nine percent had a confirmed FAP and were operated: in 61% of them a colorectal cancer was found, and 91% of these died. Conclusions: The results of the surgical treatment of FAP are satisfactory. Nevertheless, family screening should be improved to reduce the high rates of mortality revealed in the study of other family members (Rev Méd Chile 2005; 133: 1043-50).