RESUMO Racional: Trauma é uma das principais causas de morte no mundo e cuidados cirúrgicos adequados são críticos para determinar a mortalidade. No Chile, morte associada a trauma é a primeira causa de mortalidade na população entre 20 e 59 anos. Para lidar com esses pacientes complexos, são necessárias habilidades cirúrgicas precisas para esses procedimentos. Autoconfiança de cirurgiões recentemente graduados na Residência em Cirurgia Geral para práticas de procedimentos de trauma no nosso país não tem sido reportada. Objetivo: Descrever nível de autoconfiança para lidar com procedimentos de trauma em cirurgiões recentemente graduados na residência de cirurgia geral. Método: Estudo transversal. Foi desenhada e aplicada uma enquete em 2015, 2016 e 2017 a cirurgiões recentemente graduados para pesquisar sobre autoconfiança e habilidades cirúrgicas para lidar com cenários de trauma. Foram avaliados 18 procedimentos cirúrgicos de trauma (incluindo procedimentos cervicais, torácicos, abdominais e vasculares) usando a 5-grade Likert Scale. O número total de procedimentos feitos durante a residência foi avaliado. Resultados: Foram incluídos 88 cirurgiões recentemente graduados. O nível de competência foi reportado como alto em procedimentos como trauma intestinal, onde 98% sentiu-se competente ou muito competente em sua reparação. Por outro lado, em traumas complexos como dano vascular maior, até 76% reportaram não se sentirem competentes. A autoconfiança nos procedimentos esteve diretamente associada com o número de procedimentos realizados. Conclusões: Cirurgiões recentemente graduados na residência de cirurgia geral reportam níveis altos de confiança para lidar com traumas de complexidade baixa e média, mas um nível menor de confiança para tratar casos de complexidade alta.

ABSTRACT Background: Trauma is one of the leading causes of death in the world and proper surgical care is critical to impact mortality. In Chile, trauma associated death ranks first as mortality cause in population between 20 and 59 years old. Appropriate surgical skills are required to deal with these complex patients. Self-confidence to practice trauma procedures after the General Surgery Residency have not been reported in our country. Aim: Describe the level of self-confidence to deal with trauma procedures of surgeons who recently graduated from a General Surgery Residency. Method: Descriptive cross-sectional study. We designed and applied a survey in 2015, 2016 and 2017 to recently graduated surgeons, to inquire about self-confidence of surgical skills to deal with trauma scenarios. Eighteen trauma surgery procedures (including cervical, thoracic, abdominal and vascular procedures) were evaluated using a 5-grade Likert scale. The number of procedures performed during the residency was also queried. Results: Eighty-eight recently graduated surgeons from 11 different training programs in Chile were included. The report of competencies was high in procedures such as intestinal injuries, were 98% felt competent or very competent in their repair. On the other hand, in complex traumas such as major vessel injury, up to 76% reported not being competent. Self-confidence on procedures was directly associated with the number of procedures performed during residency. Conclusions: Recently graduated surgeons from General Surgery Programs report high levels of confidence to deal with low and intermediate complexity traumas, but a lower level of confidence to treat high complexity cases.

Abstract: This article is a reflection on chance as a scientific object, starting from a materialistic point of view. I analyze the relationship between motion and complexity by introducing the notion of an open system and the categories that result from it: state of nature and observable, to review the debate on chance and certainty.

Résumé: Cet article est une réflexion sur le hasard en tant qu'objet scientifique, et en partant d'un point de vue matérialiste. On considère la relation entre mouvement et complexité en introduisant la notion de système ouvert et les catégories qui en découlent : état de la Nature et observables, ce qui permet de revoir le débat sur le hasard et la certitude.

Introduction: Surgery is the most effective treatment for patients with hepatic hydatid cysts (HHC). Currently there is no consensus whether open or laparoscopic surgery is the best treatment. The aim of this study is to describe the surgical technique and the results of laparoscopic radical surgery (pericystectomy). Material and methods: Non-concurrent cohort study. We included patients with uncomplicated HHC in which it was performed a laparoscopic radical pericystectomy between 2007 and 2015 at the Clinical Hospital of the Pontificia Universidad Catolica de Chile. Demographic and clinical variables, HHC characteristics, morbi-mortality and recurrence at follow-up were recorded. Results: Twenty-four patients were operated. The median age was 35 years (3-79). The median HHC size was 8 centimeters (3-15). Postoperative complications occurred in 4 cases (16%); one patient had a biliary fistula (4.1%). There was no mortality in this study and the hospital stay was 3 days (2-25). Median follow-up was 57.5 months (9-106); a case of hepatic recurrence requiring another surgery was observed. Conclusions: The radical treatment of uncomplicated HHC by laparoscopic surgery is feasible and safe; when compared with existing literature there is no differences in morbi-mortality or recurrence.

Introducción: La cirugía es el tratamiento más efectivo para los pacientes portadores de quistes hidatídicos hepáticos (QHH). Actualmente no existe consenso si la cirugía abierta o laparoscópica es la mejor vía de tratamiento. El objetivo del presente estudio es describir la técnica quirúrgica y los resultados de la cirugía radical (periquistectomía) por vía laparoscópica. Materiales y métodos: Estudio de cohorte no concurrente. Se incluyeron a los pacientes portadores de QHH no complicados en los que se realizó periquistectomía radical laparoscópica entre los años 2007 y 2015 en el Hospital Clínico de la Pontificia Universidad Católica de Chile. Se consignaron variables demográficas, clínicas, características del QHH, morbimortalidad y recurrencia en el seguimiento. Resultados: Se operaron 24 pacientes. La mediana de edad fue de 35 años (3-79). La mediana de tamaño del QHH fue de 8 cm (3-15). Las complicaciones postoperatorias se presentaron en 4 casos (16%); un paciente presentó una fístula biliar (4,1%). No hubo mortalidad en este estudio y la estadía hospitalaria fue de 3 días (2-25). La mediana de seguimiento fue de 57,5 meses (9-106); se observó un caso de recurrencia a nivel hepático que requirió otra cirugía. Conclusiones: El tratamiento radical de los QHH no complicados por vía laparoscópica es factible y seguro; al compararlo con la literatura existente no se aprecian diferencias en la morbimortalidad ni recurrencia.

Earthquakes, as a natural phenomenon and their consequences upon structures, have been addressed from deterministic, pseudo-empirical and primary statistical-probabilistic points of view. In the latter approach, 'primary' is meant to suggest that randomness has been artificially introduced into the variables of investigation. An alternative view has been advanced by a number ofresearchers that have classified earthquakes as chaotic from an ontological perspective. Their arguments are founded in the high degree of non-linearity of the equations ruling the corresponding seismic waves. However, the sensitivity of long time behavior of dynamic systems to variations in initial conditions, known as the Chaos Paradigm appears as a by-product of a deeper insight into natural phenomena known as Theory of Open Dynamical Systems ODS. An open system is currently defined as the relation between a part of nature, the main system which contains the observations we make, and its surrounding environment. ODS theory has been applied to different research subjects including physics, chemistry, and biology, for identifying and controlling undesired chaotic behavior in highly nonlinear dynamic systems. It is suggested that earthquakes and their interaction with structures constitute an example of an open system. Recognizing that in Earthquake Engineering the application of those concepts has not been previously investigated, in this paper a discussion related to the use of ODS concepts in that particular field is presented. Using the most basic case of a linear elastic single degree offreedom SDOF oscillator, differences in the prediction of the response of the system subjected to only one ground motion using a Newton classical approach and ODS concepts, which involve stochastic processes, are compared. Conclusions about the consequences of the application of ODS theory for re-understanding Earthquake Engineering are presented, and a general critique to primary probabilistic approaches for addressing the same problem is formulated.

Los terremotos, como fenómeno natural y sus consecuencias en estructuras han sido abordados desde perspectivas deterministas, pseudo-empíricas y desde un punto de vista probabilístico-estadístico primario. En este último enfoque, el adjetivo 'primario' significa que la aleatoriedad ha sido introducida en forma artificial en las variables de investigación relevantes en Ingeniería Sísmica. Una perspectiva alternativa ha sido planteada por investigadores que han clasificado los terremotos, desde un punto de vista ontológico, como fenómenos caóticos. Sus argumentos se fundamentan en el alto grado de no-linealidad y complejidad de las ecuaciones que gobiernan la ecuación de las ondas sísmicas. Sin embargo, la sensibilidad de la respuesta dinámica en el largo plazo debido a pequeñas variaciones en las condiciones iniciales, conocido como el Paradigma del Caos, aparece como un subproducto de una mirada más profunda dentro de fenómenos naturales en general, llamada Teoría de Sistemas Dinámicos Abiertos ODS. Un sistema abierto se define como la relación entre una parte de la naturaleza, el sistema primario que contiene nuestras observaciones, y el sistema que lo contiene. Los principios de ODS han sido aplicados a distintas disciplinas científicas tales como la física, la química y la biología, con la intensión de identificar y controlar comportamientos caóticos no deseados en sistemas altamente no-lineales. Se postula que los terremotos y su interacción con estructuras constituyen un caso de un sistema abierto. Reconociendo que en Ingeniería Sísmica la aplicación de dichos conceptos no ha sido anteriormente investigada, en este artículo se presenta una discusión sobre su posible uso en dicha disciplina. Utilizando un modelo que representa el caso más básico de un oscilador de un grado de libertad con rigidez lineal elástica sometido sólo a un registro sísmico, se discuten las diferencias en la respuesta del oscilador obtenida usando la dinámica clásica de Newton y conceptos de ODS que incluyen procesos estocásticos como el que se utiliza en esta contribución. Conclusiones sobre las consecuencias de la aplicación de ODS son formuladas para re-entender la Ingeniería Sísmica, incorporando una crítica a enfoques probabilísticos primarios para abordar el mismo problema.

Background: There is a growing interest in alternative techniques for aortic valve replacement (AVR). Therefore it is important to have updated results of conventional AYR as a valid comparative standard. Aim: To evaluate both perioperative and ¡ate morbidity and mortality in patients undergoing conventional AVR, with either mechanical (RVAm) or biological (RVAb) prostheses. Patients and methods: Retrospective review of medical records and operative protocols of patients undergoing AVR between January 1995 and December 2005. Patients with previous cardiac surgery, aortic balloonplasty or simultaneous cardiovascular procedures were excluded. Results: During the study period, 788 patients underwent AVR and 317 met the inclusion criteria. Of the latter, 175patients aged 13 to 83years (63% males) were subjected to AVRm and 142patients aged 49 to 87 years (64% males), were subjected to AVRb. Five (1.6%) patients died during the perioperative period (one AVRm and four AVRb). All were older than 65years. Perioperative complications were recorded in 29 and 25% of patients in AVRm and AVRb groups, respectively (NS). During a median follow-up of six years, complications were recorded in 12 and 4% of patients in AVRm and AVRb groups, respectively (p <0.05). The actuarial survival for AVRm group at 1, 5 and 10years, was 96, 92 and 87%, respectively. The figures for AVRb group were 95, 86 and 83%, respectively (NS). The 10 year reintervention free survival was 97% for the AVRm group and 84% for the AVRb (p <0.05). Conclusions: Perioperative mortality and rates of complications of AVR in this series of patients are low, which compares favorably with other series (Rev Méd Chile 2009; 137:1153-62).