Alejandro Raddatz

Predictors of nonalcoholic steatohepatitis (NASH) in obese patients undergoing gastric bypass.

Background: Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are conditions gaining increasing recognition in hepatology as a potential cause of cirrhosis and end-stage liver disease. Obesity is one of the main risk factors. The aims of this study were to determine the frequency of NAFLD in obese patients and to identify variables that predict NASH. Methods: A prospective study was conducted of obese patients undergoing gastric bypass over a 20-month period. Assessment included liver function tests and evaluation of insulin resistance with the homeostatic model assessment (HOMA-IR). Liver biopsy was performed in all patients at the time of surgery. Clinical and biochemical variables were analyzed using a multivariate analysis to identify independent predictors of NASH. Results: 127 consecutive patients were included (62% female, 38% male, mean age 40±11 years, mean body mass index 42±6 kg/m2). Arterial hypertension was present in 52 patients (41%) and type 2 diabetes in 18 (14%). NAFLD was confirmed in 80 patients (63%), 47 (37%) had simple steatosis, and 33 (26%) had NASH. Cirrhosis was found in 2 patients corresponding to 1.6% of the total population. On multivariate analysis, AST >31 (IU/L) (OR 3.38, CI 1.17-9.8) and HOMA-IR >5.8 (OR 4.18, CI 1.39-12.49) independently predicted NASH. Conclusions: NAFLD is highly prevalent in morbidly obese patients. A high proportion of these patients exhibit NASH on histological examination. Insulin resistance represents the main predictor of NASH.

Cholesterol saturation, not proteins or cholecystitis, is critical for crystal formation in human gallbladder bile

BACKGROUND & AIMS Biliary proteins are promoters of cholesterol crystallization in artificial model bile. However, their pathogenic importance for cholesterol precipitation in native gallbladder bile (GB) is uncertain. The aim of this study was to evaluate the significance of biliary lipids and proteins on cholesterol crystal detection time (ChCDT) of GB in patients with gallstones. METHODS ChCDT and concentrations of lipids, albumin, mucins, aminopeptidase N, alpha1-acid glycoprotein, haptoglobin, and immunoglobulins (Igs) were measured in GB of 92 patients, 52 of whom had cholesterol gallstones. RESULTS ChCDT was markedly reduced in gallstone patients. Compared with patients without gallstones, they had a significant increase in cholesterol saturation and total protein, albumin, mucin, and IgG biliary concentrations. In univariate analysis, ChCDT of GB was significantly correlated with cholesterol saturation and total lipid, protein, Ig, aminopeptidase N, and alpha1-acid glycoprotein concentrations. However, stepwise logistic regression analysis showed that only cholesterol saturation independently correlated to ChCDT. Gallbladder inflammation correlated with the concentration of Igs, but subtraction of IgG from GB did not modify the ChCDT. CONCLUSIONS Biliary cholesterol transport and saturation, but not proteins, appear critical for the cholesterol crystallization abnormality observed in native bile from patients with gallstones.

Increased activity of hepatic microsomal triglyceride transfer protein and bile acid synthesis in gallstone disease

A strong interrelationship exists between the regulation of bile acid (BA) metabolism and hepatic very low density lipoprotein (VLDL) production. We have recently shown that BA synthesis is increased in gallstone disease. We investigated the activity of hepatic microsomal triglyceride transfer protein (MTTP) as a surrogate of VLDL production, BA synthesis, and mRNA expression levels of proteins that regulate fatty acid (FA) metabolism in the liver of gallstone (GS) patients compared with GS‐free patients. Twenty‐seven volunteers subjected to elective surgery; 9 were GS‐free and 18 with GS agreed to have a liver biopsy. We quantified by a fluorescence assay the activity of MTTP and by quantitative reverse‐transcription PCR (RT‐PCR) the mRNA content of hepatic MTTP and genes that regulate hepatic sterol and FA metabolism. Plasma was assayed for lathosterol and 7α‐hydroxy‐4‐cholesten‐3‐one. Liver histology was normal in GS and GS‐free patients. Serum VLDL triglycerides and apoB were significantly increased in GS. Hepatic triglycerides tripled in GS (P < 0.001) compared with GS‐free. MTTP activity increased 70% (P < 0.001). Serum lathosterol and hepatic cholesterol concentrations, and mRNA expressions of MTTP, CD36, and FABP1 were similar in GS‐free and GS patients. Hepatic mRNA expression of hydroxy‐3‐methylglutaryl‐coenzyme A reductase (HMGR) and 3‐hydroxyl‐3‐methyl‐glutaryl‐CoA synthase (HMGS) were significantly decreased—40% and 27%, respectively—in GS. Serum 7α‐hydroxy‐4‐cholesten‐3‐one was 75% higher, and mRNA expression of CYP7A1 was increased sevenfold (P < 0.001) in GS. Conclusion: Hepatic MTTP activity and BA synthesis are increased in GS. Results suggest that hepatic VLDL production and trafficking of BA are increased in gallstone patients. (HEPATOLOGY 2007;45:1261–1266.)

Laparoscopic sleeve gastrectomy conversion to Roux-en-Y gastric bypass: experience in 50 patients after 1 to 3 years of follow-up

BACKGROUND Sleeve gastrectomy (SG) is currently one of the most frequently performed bariatric interventions worldwide due to its simplicity and good weight loss results. Nevertheless, SG failure and complications are increasingly being observed as the number of procedures increases. OBJECTIVES To report our results in converting SG to revisional laparoscopic Roux-en-Y gastric bypass (R-LRYGB). SETTING University Hospital, Chile. METHODS Retrospective analysis of our bariatric surgery database. Patients who underwent R-LRYGB after SG between June 2005 and April 2015 were identified. Demographic characteristics, anthropometrics, preoperative workup, and perioperative data were retrieved. Total weight loss (TWL), excess weight loss (EWL), and clinical progression over 3 years were registered. RESULTS Fifty patients were identified, mean age 39±8.4 years, 42 (84%) women; median body mass index previous to R-LRYGB was 33.8 (31-36) kg/m2. Indications for revision were weight regain (n = 28, 56%), gastroesophageal reflux disease (n = 16, 32%), and gastric stenosis (n = 6, 12%). In weight-regain patients, mean follow-up at 3 years was 72.2% and median percentage of total weight loss at 12 and 36 months was 18.5 (12-24) and 19.3 (8-23), respectively; percentage of excess weight loss at 12 and 36 months was 60.7 (37-82) and 66.9 (26-90), respectively. Over 90% of gastroesophageal reflux disease patients resolved or improved symptoms. All patients with gastric stenosis resolved symptoms after conversion. There were no major complications. CONCLUSION R-LRYGB is a feasible, effective, and well-tolerated alternative in selected patients with failed SG in which other therapies have been insufficient to either maintain weight loss or resolve complications. However, long-term follow-up is still needed.

Experiencia de 18 años de cirugía de obesidad en la Pontificia Universidad Católica de Chile

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 performed 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 femoles and preoperative mean body mass Index 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 at five years 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 of this 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

Splenic rupture as complication of sleeve gastrectomy

Splenic rupture as complication of sleeve gastrectomy Napoleón Salgado, M.D.*, Pablo Becerra, M.D., Eduardo Briceño, M.D., Allan Sharp, M.D., Alejandro Raddatz, M.D. Bariatric Surgery Program, Pontificia Universidad Católica de Chile Faculty of Medicine, Santiago, Chile Department of Digestive Surgery, Pontificia Universidad Católica de Chile Faculty of Medicine, Santiago, Chile Received July 19, 2011; accepted July 26, 2011 Surgery for Obesity and Related Diseases 8 (2012) e72–e74