Abstract Objective: The aim of this study was to assess the risk factors associated with 30-day hospital readmissions after a cholecystectomy. Methods: We conducted a case–control study, with data obtained from UC-Christus from Santiago, Chile. All patients who underwent a cholecystectomy between January 2015 and December 2019 were included in the study. We identified all patients readmitted after a cholecystectomy and compared them with a randomized control group. Univariate and multivariate analyses were conducted to identify risk factors. Results: Of the 4866 cholecystectomies performed between 2015 and 2019, 79 patients presented 30-day hospital readmission after the surgical procedure (1.6%). We identified as risk factors for readmission in the univariate analysis the presence of a solid tumor at the moment of cholecystectomy (OR = 7.58), high pre-operative direct bilirubin (OR = 2.52), high pre-operative alkaline phosphatase (OR = 3.25), emergency admission (OR = 2.04), choledocholithiasis on admission (OR = 4.34), additional surgical procedure during the cholecystectomy (OR = 4.12), and post-operative complications. In the multivariate analysis, the performance of an additional surgical procedure during cholecystectomy was statistically significant (OR = 4.24). Conclusion: Performing an additional surgical procedure during cholecystectomy was identified as a risk factor associated with 30-day hospital readmission.

Resumen Objetivo: El objetivo de este estudio fue evaluar los factores de riesgo asociados al reingreso hospitalario en los primeros 30 días post colecistectomía. Métodos: Estudio de casos-controles con datos obtenidos del Hospital Clínico de la UC-Christus, Santiago, Chile. Se incluyeron las colecistectomías realizadas entre los años 2015-2019. Se consideraron como casos aquellos pacientes que reingresaron en los 30 primeros días posterior a una colecistectomía. Se realizó un análisis univariado y multivariado de diferentes posibles factores de riesgo. Resultados: De un total de 4866 colecistectomías, 79 pacientes presentaron reingreso hospitalario. Los resultados estadísticamente significativos en el análisis univariado fueron; tumor sólido al momento de la colecistectomía (OR = 7.58) bilirrubina directa preoperatoria alterada (OR = 2.52), fosfatasa alcalina preoperatoria alterada (OR = 3.25), ingreso de urgencia (OR = 2.04), coledocolitiasis al ingreso (OR = 4.34) realización de otros procedimientos (OR = 4.12) y complicaciones postoperatorias. En el análisis multivariado sólo la realización de otro procedimiento durante la colecistectomía fue estadísticamente significativa (OR = 4.24). Conclusión: La realización de otros procedimientos durante la colecistectomía es un factor de riesgo de reingreso hospitalario en los 30 días posteriores a la colecistectomía.

ABSTRACT BACKGROUND: Gallbladder polyps are becoming a common finding in ultrasound. The management has to consider the potential risk of malignant lesions. AIMS: The aim of this study was to analyze the ultrasound findings in patients undergoing cholecystectomy due to gallbladder polyps and compare them for histopathological findings (HPs). METHODS: Patients with an ultrasonographic diagnosis of gallbladder polyp and who underwent cholecystectomy from 2007 to 2020 were included in the study. RESULTS: A total of 447 patients were included, of whom 58% were women. The mean age was 45±12 years. The mean size of polyps in US was 7.9±3.6 mm. Notably, 9% of polyps were greater than 10 mm, and single polyps were significantly larger than the multiple ones (p=0.003). Histopathological findings confirmed the presence of polyps in 88.4%, with a mean size of 4.8±3.4 mm. In all, 16 cases were neoplastic polyps (4.1%), 4 of them being malignancies, and all were single and larger than 10 mm. We found a significant correlation between ultrasound and histopathological findings polyp size determination (r=0.44; p<0.001). The Bland-Altman analysis obtained an overestimation of the US size of 3.26 mm. The receiver operating characteristic (ROC) curve analysis between both measures obtained an area under the receiver operating characteristic curve (AUC) of 0.77 (95%CI 0.74–0.81). Ultrasound polyps size larger than 10 mm had an odds ratio (OR) of 8.147 (95%CI 2.56–23.40) for the presence of adenoma and malignancy, with a likelihood ratio of 2.78. CONCLUSIONS: There is a positive correlation and appropriate diagnostic accuracy between ultrasound size of gallbladder polyps compared to histopathological records, with a trend to overestimate the size by about 3 mm. Neoplastic polyps are uncommon, and it correlates with size. Polyps larger than 10 mm were associated with adenoma and malignancy.

RESUMO RACIONAL: Os pólipos da vesícula biliar estão se tornando um achado comum na ultrassonografia (US). O manejo deve levar em consideração o risco de lesões malignas. OBJETIVOS: Analisar os achados da ultrassonografia em pacientes submetidos à colecistectomia por pólipos vesicais e compará-los com os achados histopatológicos. MÉTODOS: Foram revisados os prontuários médicos dos pacientes com diagnóstico ultrassonográfico de pólipo vesicular e submetidos à colecistectomia no período de 2007 a 2020. RESULTADOS: Foram incluídos no estudo 447 pacientes. A média de idade foi 45±12anos, sendo 58% mulheres. O tamanho médio dos pólipos na US foide 7,9±3,6mm. Nove por cento foram maiores que 10 mm, e os pólipos únicos encontrados foram maiores do que os múltiplos (p=0,003). A HP confirmou a presença de pólipos em 88,4%, tamanho médio 4,8±3,4mm. Dezesseis eram pólipos neoplásicos (4,1%) e quatro deles malignos, únicos e maiores que 10 mm. Foi encontrado correlação significativa entre a determinação do tamanho do pólipo ao ultrassonografia e histopatológicos (r=0,44; p<0,001). A análise de Bland-Altman obteve uma superestimação do tamanho do pólipo ao US em 3,26 mm. A análise da curva da característica de operação do receptor entre as duas medidas obteve uma área sob a curva curva da característica de operação do receptor (AUC) de 0,77 (IC95% 0,74–0,81). Pólipos ao ultrassonografia maiores que 10 mm apresentaram razão de chance (OR) de 8,147 (IC95% 2,56–23,40) para presença de adenoma e malignidade, com razão de verossimilhança de 2,78. CONCLUSÕES: Há uma correlação positiva e acurácia diagnóstica apropriada entre o tamanho dos pólipos da vesícula biliar por ultrassonografia em comparação com os achados histopatológicos, com uma tendência de superestimar o tamanho em cerca de 3 mm. Pólipos maiores que 10 mm foram associados a adenoma e malignidade.

Abstract Introduction: Laparoscopic cholecystectomy (LC) is one of the most common surgical procedures in our country. Postcholecystectomy diarrhea is an unrecognized entity, with a reported prevalence between 0.9 and 35.6%, nonetheless in Chile this has not been clearly defined. Objective: To determine the prevalence and characteristics of diarrhea following elective laparoscopic cholecystectomy in our institution. Material and methods: A structured questionnaire about consistency and defecation frequency was applied to adult patients summited to an elective LC between December 2014 and February 2015, by a telephone survey within 4 and 6 months after the surgical procedure. Postcholecystectomy diarrhea was defined as the presence of liquid or unusually disrupted faecal material beginning after LC. Persistent diarrhea was established when diarrhea continued for a period longer than four weeks. Results: One hundred patients were included (73% women). The overall prevalence of postcholecystectomy diarrhea was 35% (n = 35). The prevalence of patients with persistent diarrhea was 15% (n = 15). In the group of patients with persistent diarrhea, complete resolution was observed on 57% of the cases (n = 8) within an average period of 99 ± 29 days. Conclusion: Post cholecystectomy diarrhea is a frequent condition in our population, with a high prevalence within the first 28 days after LC. In most patients it resolved within 6 months.

Resumen Introducción: La colecistectomía laparoscópica es una de las intervenciones quirúrgicas más frecuentes en nuestro país. La diarrea poscolecistectomía es una entidad poco reconocida, con una prevalencia descrita entre el 0,9 y 35,6%, sin embargo, en Chile esto no ha sido claramente definido. Objetivo: Determinar la prevalencia y características de la diarrea poscolecistectomía laparoscópica electiva en una muestra de pacientes chilenos. Material y métodos: Se aplicó una encuesta telefónica estructurada sobre consistencia y frecuencia de deposiciones, entre 4 y 6 meses después de la intervención, a los pacientes adultos operados de colecistectomía laparoscópica electivamente entre diciembre de 2014 y marzo de 2015. Se definió como «diarrea poscolecistectomía» la presencia de deposiciones líquidas o inusualmente disgregadas que hubiesen comenzado posteriormente a la intervención y se estableció el término de «diarrea prolongada» como la duración de síntomas mayor de 4 semanas. Resultados: Se encuestó a 100 pacientes (73% de mujeres). La prevalencia global de diarrea poscolecistectomía fue del 35% (n = 35). La prevalencia de pacientes con diarrea prolongada fue del 15% (n = 15). En el grupo con diarrea prolongada, se observó resolución completa de esta en el 57% de los pacientes (n = 8) en un plazo medio de 99 ± 29 días. Conclusión: La diarrea poscolecistectomía es una entidad frecuente en nuestra población, con una alta prevalencia dentro de los primeros 28 días posteriores a la intervención. En la mayoría de los pacientes se resuelve en los primeros 6 meses.

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.

Background: Endoscopic submucosal dissection (ESD) is a minimally invasive procedure that allows curative treatment of early gastric cancer (EGC) in selected patients. Aim: To report our initial experience with ESD. Material and Methods: Analysis of prospective data from 16 patients aged 61 to 84 years, who underwent ESD between December 2011 and June 2014. Tumor type, operative time, hospitalization length, oncologic outcomes, complications and short-term follow up were registered. Results: En-block resection was achieved in all cases. The median operative time was 135 min (range: 50-320 min). Specimens' median size was 3.5 cm (range: 3-10). All the resections were R0. In 14 patients ESD was considered curative. In two patients, ESD was considered potentially non-curative due to the presence pathological risk factors for lymph-node metastases in the biopsy specimen. Both patients underwent laparoscopic gastrectomy with lymph-node dissection. There was one case of gastric wall perforation that was repaired by laparoscopic suture. There was no mortality. The median follow-up time was 15 months (range: 2-30 months). Conclusions: ESD is a feasible and safe procedure in our institution with good results in this initial experience.

Background: Bariatric surgery is the gold-standard treatment for morbid obesity because it has low morbidity rates in high-volume centers and generates long term sustained weight loss. Aim: To describe our experience in bariatric surgery since the creation of our bariatric program in 1992. Material and Methods: Retrospective analysis of all patients subjected to bariatric surgery from 1992 to December 2010. Data was obtained from the electronic institutional registry. The Procedures per-formed were open and laparoscopic Roux-en-Ygastric bypass (BPGA and BPGL, respectively), laparoscopic adjustable gastric band (BGAL) and laparoscopic sleeve gastrectomy (GML). Results: A total of 4943 procedures were performed, 768 (16%) BPGA, 2558 (52%) BPGL, 199 (4%) BGAL and 1418 (29%) GML. The number of procedures progressively increased, from 100 cases in 2000 to over 700 cases in 2008. Proportion of femóles and preoperative mean body mass Índex fluctuated between 69 and 79% and 35 and 43 kg/m², respectively, among the different procedures. Early and late complications fluctuated between Oto 1% (higher on BPGA) and 3 to 32.7% (higher on BGAL), respectively. The excess weight lost atfiveyears was 76.1 % in BPGA, 92.5%o in BPGL and 53.7% in BGAL. The figure for GML at three years was 73.7%. Conclusions: The complication rates ofthis series of patients are similar to those reported in large series abroad. BPGL is still the most effective procedure; however GML is an attractive alternative for less obese patients.

Background: Early gastric cancer involves mucosa and submucosa, independent of lymph node involvement. Radical gastrectomy is the standard treatment. Aim: To assess long term survival of patients operated for an early gastric cancer. Material and methods: Retrospective Rev iew of medical and pathology records of patients subjected to a gastrectomy for an early gastric cancer, between 1975 and 2002. All were treated using a standardized protocol and staged according to 2002 TNM classification of the American Joint Committee of Cáncer (AJCC). Demographic and pathologic features, operation performed and long term survival were recorded. Survival was analyzed using Kaplan-Meier method. Results: The series is comprised by 64 males and 41 females aged 61 + 1 years. Tumor was located in the upper third of the stomach on 33 subjects and a total gastrectomy was performed in 53. Pathology showed an intestinal type adenocarcinoma in 82 and a diffuse type in 23. In patients with involvement of mucosa and submucosa, 24 ± 14 and 22 ± 14 lymph nodes were excised, respectively. Lymph node involvement was present in 8% and 22% of patients with involvement of mucosa and submucosa, respectively. Five years survival was 94% and 78% in patients without and with lymph node involvement, respectively. Survival among patients in stage IA and IB was 94% and 76%, respectively. Multivariate analysis showed that the lymph node involvement was an independent mortality risk factor. Conclusions: Total gastrectomy in patients with early gastric cancer is associated with a good survival. Lymph node involvement is a mortality risk factor.

Bouveret syndrome is a duodenal obstruction caused by a biliary stone. Aim: To report patients with Bouveret syndrome. Material and Methods: Retrospective review of medical records of patients with Bouveret syndrome treated between 1976 and 2006. Results: We report three women and one man with a mean age of 62.5 years. None had a previous diagnosis of cholelithiasis. AH presented with colicky pain in the right upper quadrant and vomiting, suggesting gastric retention. The diagnosis was suspected after a barium meal in two patients and with a CT scan on the other two. The endoscopical extraction or fragmentation of stones was attempted in three patients but was successful only in one. Three patients were operated and a stone impacted in the first portion of the duodenum was identified, along with a cholecystoduodenal fistula. A duodenostomy and stone extraction was performed. One patient was subjected to a cholecystectomy fistula repair and gastrojejunoanastomosis. No patient died and all were discharged within 8 to 12 days after surgery. Conclusions: Bouveret syndrome is an uncommon complication of cholelithiasis. Endoscopy can be diagnostic and therapeutic. Surgery is the other therapeutic option

Background: Achalasia is characterized by an incomplete relaxation of the lower esophageal sphincter. The best treatment is surgical and the laparoscopic approach may have good results. Aim: To assess the results of laparoscopic Heller myotomy among patients with achalasia. Material and methods: Prospective study of patients subjected to a laparoscopic Heller myotomy between 1995 and 2004. Clinical features, early and late operative results were assessed. Results: Twenty seven patients aged 12 to 74 years (12 females) were operated. All had disphagia lasting for a mean of 32 months. Mean lower esophageal sphincter pressure ranged from 18 to 85 mmHg. Eight patients received other treatments prior to surgery but symptoms persisted or reappeared. The preoperative clinical score was 7. No patient died and no procedure had to be converted to open surgery. In a follow up of 21 to 131 months, all patients are satisfied with the surgical results and the postoperative clinical score is 1. Only one patient with a mega esophagus maintained a clinical score of six. Conclusions: In this series of patients, laparoscopic Heller myotomy was an effective and safe treatment for esophageal achalasia

Background: The development of the laparoscopic surgery has allowed its incorporation to the surgical treatment of gastric cancer. Aim: To evaluate the feasibility and safety of laparoscopic gastrectomy in gastric cancer in our institution. Patients and methods: Prospective data in four patients who underwent laparoscopic gastrectomy for gastric cancer from May to August of 2005 was reviewed. Demographic data, clinical characteristics and postoperative results were registered. Patients were staged according to TNM-AJJC staging system. Results: Four patients aged 48 to 80 years (three males), underwent a completely laparoscopic R0 gastrectomy with lymph node dissection. Two patients underwent total gastrectomy. A subtotal Billroth II gastrectomy was performed in the other two patients. The mean operative time was 260 minutes (Range 180-330). There were no conversions to open surgery. The mean postoperative hospital stay was 6.5 days (Range 6-7 days). There were no complications. According to pathology, one patient presented carcinoma in stage IA, two patients in stage IB and one patient in stage IIIB. The mean number of lymph nodes dissected was 40 (Range 35-54). Conclusions: Laparoscopic gastrectomy is a feasible procedure with good postoperative results in this preliminary experience