Utilidad del dispositivo de potenciación del esfínter esofágico distal (LINX®) para pacientes con reflujo gastroesofágico / Usefulness of the distal esophageal sphincter enhancement device (LINX®) for patients with gastroesophageal reflux

Resumen La fundoplicatura de Nissen laparoscópica (FNL) es el gold standard del tratamiento quirúrgico de pacientes con reflujo gastroesofágico patológico (RGE), con perfil de seguridad y resultados a largo plazo satisfactorios en un 80%. En la última década, se ha propuesto el uso de un dispositivo de potenciación del esfínter esofágico inferior (MSA) comercializado como LINX® (de Ethicon, Johnson & Johnson), como alternativa a la cirugía antirreflujo. El dispositivo consiste en una cadena expansible de cuentas de titanio con un núcleo magnético diseñadas para aumentar el tono del esfínter esofágico inferior (EEI) y evitar su relajación inadecuada. Los resultados preliminares han sido alentadores, sin embargo, no está exento de complicaciones. Las indicaciones más aceptadas son: RGE con motilidad esofágica normal y sin esofagitis erosiva, hernia hiatal < 3 cm, IMC <35 kg/m2 y pacientes sin cirugías gastroesofágicas previas. Se instala por vía laparoscópica. Los efectos adversos más importantes son: disfagia con necesidad de dilataciones endoscópicas, y, retiro del dispositivo, entre 1% y 7% a los 2,5 años. La mayoría de los estudios tienen limitaciones metodológicas, conflictos de interés, falta de resultados objetivos y seguimientos a largo plazo, impidiendo llegar a conclusiones extrapolables respecto a la eficacia del MSA.

Laparoscopic Nissen Fundoplication (LNF) is the gold standard of surgical treatment for patients with Gastroesophageal Reflux Disease (GER), with safety profile and long term results satisfactory in 80%. In the last decade, the use of a Lower Esophageal Sphincter Enhancement Device (LESD), marketed as LINX® (from Ethicon, Johnson & Johnson), has been proposed as an alternative to Anti-Reflux Surgery. The device consists of an expandable chain of titanium beads with a magnetic core designed to increase the tone of the lower esophageal sphincter (LES) and prevent its improper relaxation. Preliminary results have been encouraging; however, it is not without complications. The most accepted indications are: GER with normal esophageal motility and without erosive esophagitis, hiatal hernia < 3 cm, BMI <35 kg/m2, and patients without previous gastroesophageal surgeries. It is installed by laparoscopy. The most important adverse effects are: dysphagia with the need for endoscopic dilations, and, removal of the device, between 1 and 7% at 2.5 years. Most of the studies have methodological limitations, conflicts of interest, lack of objective results and long-term follow-up, preventing the reaching of extrapolable conclusions regarding the efficacy of MSA.

Epidemiología de la pancreatitis aguda en Chile entre los años 2013 y 2018 / Epidemiology of acute pancreatitis in Chile between 2013 and 2018

Background: The worldwide incidence of acute pancreatitis (AP) is increasing. Aim: To determine the national incidence of AP between 2013 and 2018. Material and Methods: Analysis of hospital discharge records available at the web page of the Statistical and Information Service of the Chilean Ministry of Health. We recorded the number of patients discharged with a diagnosis of AP, excluding chronic pancreatitis and pancreatic cancer, between 2013 and 2018. We also recorded length of hospital stay, age, etiology, and lethality. Rates of raw and age-adjusted incidence were calculated. Results: During the study period, 46,420 patients with AP were discharged, with an incidence rate ranging between 39 and 43.7/100,000 inhabitants, and a non-significant increase along time of 8.6%. There are important differences between the average adjusted rates of Northern (Arica to Metropolitan) and Southern regions (O'Higgins to Magallanes), with rates of 36.9 and 53.6/100,000 inhabitants respectively (p < 0.01). The average hospital stay was 11 days. Two thirds of cases were aged between 20 and 64 years. The case fatality was 4.2%, with no decrease between 2013 and 2018. The mortality rate was 1.6/100,000 inhabitants. Conclusions: The annual incidence of AP is 42.6/100,000 inhabitants, with geographical differences from North to South, which can be associated with the high frequency of biliary tract disease in aboriginal ethnic groups. The age distribution and length hospital stay were stable over time.

Estudio de biodisponibilidad comparativa de dos formulaciones de risperidona existentes en el mercado chileno / Comparative bioavailability study of two formulations of risperidone available in the Chilean market

BACKGROUND: Bioavailability of a particular drug can vary according to the formulation used. Therefore, studies of comparative bioavailability of different formulations of a same drug are worthwhile. AIM: To compare the bioavailability of two risperidone formulations available in the Chilean market. MATERIAL AND METHODS: The bioavailability of a local risperidone formulation (Spiron) was compared with the original formulation of the drug (Risperdal) in 12 healthy volunteers, aged 19 +/- 1 years. A single dose of 3 mg was given orally, using a randomized double blind protocol in two periods. Fifteen blood samples were obtained at regular intervals, until 24 h after drug administration. Risperidone plasma levels were measured by high pressure liquid chromatography. pharmacokinetic parameters were calculated using a computer program that is independent of compartmental analysis. RESULTS: The area under the curve of plasma concentration versus time, from 0 to infinite (ABC0-infinity) and from 0 to 24 h (ABC0-24), early exposure (ABC from 0 to maximal time) and maximal plasma concentrations were significantly lower for Spiron. Half life time and time to achieve the maximal concentration were similar for the two formulations. CONCLUSIONS: According to bioequivalence tests suggested by the Food and Drug Administration (FDA) of the United States (90 per cent confidence interval for the difference of long transformed mean pharmacokinetic parameters), the formulations Risperdal and Spiron, cannot be considered interchangeable.

Estudio de los efectos del ultrasonido en el tejido embrionario in vitro. / Effects of ultrasound on the embryonic tissue in vitro

Esbozos de miembros de ave con 144 horas de incubacion fueron sometidos a irradiacion ultrasonica con una frecuencia de 50 kHz y una intensidad de 6.4 mW/cm2 durante 10,20 y 30 minutos respectivamente.Se desdriben los hallazgos histologicos, entre lo que llama la atencion la presencia de focos de necrosis en aquellos irradiados durante 20 minutos. El histograma mostro disminucion significativa de las mitosis en los de 10 y 20 minutos, y aumento notorio en el de 30 minutos. Se compara lo encontrado con lo descrito por la literatura la literatura