Rapid improvement of hepatic steatosis and liver stiffness after metabolic/bariatric surgery: a prospective study.

Metabolic dysfunction-associated steatotic liver disease (MASLD) and related steatohepatitis (MASH) are common among obese patients and may improve after metabolic/bariatric surgery (MBS). 93 Patients undergoing MBS in 2021-2022 were prospectively enrolled. Liver stiffness measurement (LSM; via vibration-controlled transient elastography [VCTE], point [pSWE] and 2D [2DSWE] shear wave elastography) and non-invasive steatosis assessment (via controlled attenuation parameter [CAP]) were performed before (baseline [BL]) and three months (M3) after surgery. 93 patients (median age 40.9 years, 68.8% female, median BL-BMI: 46.0 kg/m2) were included. BL-liver biopsy showed MASLD in 82.8% and MASH in 34.4% of patients. At M3 the median relative total weight loss (%TWL) was 20.1% and the median BMI was 36.1 kg/m2. LSM assessed by VCTE and 2DSWE, as well as median CAP all decreased significantly from BL to M3 both in the overall cohort and among patients with MASH. There was a decrease from BL to M3 in median levels of ALT (34.0 U/L to 31 U/L; p = 0.025), gamma glutamyl transferase (BL: 30.0 to 21.0 U/L; p < 0.001) and MASLD fibrosis score (BL: - 0.97 to - 1.74; p < 0.001). Decreasing LSM and CAP, as well as liver injury markers suggest an improvement of MASLD/MASH as early as 3 months after MBS.

The deep abdominal ultrasound transducer (DAX) increases the success rate and diagnostic accuracy of shear wave elastography for liver fibrosis assessment in patients with obesity-A prospective biopsy-controlled study.

BACKGROUND: Obesity impacts the diagnostic accuracy of shear wave elastography (SWE). A deep abdominal ultrasound transducer (DAX) capable of point (pSWE) and two-dimensional (2D)-SWE has recently been introduced to address this issue. METHODS: We performed a prospective study in a cohort of mostly patients with obesity undergoing liver biopsy with a high prevalence of metabolic dysfunction-associate steatotic liver disease (MASLD). Liver stiffness measurement (LSM) was measured using vibration-controlled transient elastography (VCTE), as well as pSWE and 2D SWE on the standard (5C1) and the DAX transducers. RESULTS: We included 129 patients with paired LSM and liver biopsy: median age 44.0 years, 82 (63.6%) women, median BMI: 43.2 kg/m2. Histologic fibrosis stages: F0: N = 55 (42.6%), F1: N = 14 (10.9%), F2: N = 50 (38.8%), F3: N = 2 (1.6%), F4: N = 8 (6.2%). VCTE-LSM failed (N = 13) or were unreliable (IQR/median ≤30% in ≥7.1 kPa, N = 14) in 20.9% of patients. The Pearson correlation of reliable VCTE-LSM with both pSWE and 2D SWE was strong (all >0.78). The diagnostic accuracy for all LSM techniques was poor for significant fibrosis (≥F2, AUC: 0.54-0.63); however, it was good to excellent for advanced fibrosis (≥F3, AUC: 0.87-0.99) and cirrhosis (F4, AUC: 0.86-1.00). In intention-to-diagnose analysis, pSWE on DAX was significantly superior to VCTE-LSM. CONCLUSIONS: pSWE- and 2D-SWE enable the non-invasive identification of advanced fibrosis and cirrhosis in patients with obese MASLD. The use of the DAX transducer for acoustic radiation force imaging (ARFI)-LSM avoids technical failures in an obese population and subsequently offers advantages over VCTE-LSM for the evaluation of fibrosis in an obese MASLD population at risk for fibrosis.

The male patient with obesity undergoing metabolic and bariatric surgery: changes in testosterone levels correlate with weight loss after one-anastomosis gastric bypass and Roux-en-Y gastric bypass.

BACKGROUND: Male obesity secondary hypogonadism (MOSH) is a common disease among men with obesity and can be associated with metabolic syndrome and a variety of metabolic problems ultimately leading to androgen deficiency. Metabolic and bariatric surgery is a well-established treatment option associated with significant weight loss and reduction in metabolic co-morbidities. OBJECTIVES: To evaluate the impact of surgery on plasma levels of sexual hormones and their effect on weight loss comparing 2 surgical methods (one-anastomosis gastric bypass [OAGB] and Roux-en-Y gastric bypass [RYGB]) in male patients with obesity. SETTING: University hospital, Austria. METHODS: Patients undergoing OAGB and RYGB between 2012 and 2017 were analyzed retrospectively. Follow-up in this study was up to 24 months. Systemic levels of sexual hormones (luteinizing hormone [LH]), follicle stimulating hormone [FSH], total testosterone [TT], sexual hormone binding globin [SHBG], 17 beta-estradiol [17bE], androstenedione [AS]) were retrieved at each visit. A linear mixed model was used to assess the correlation between changes in testosterone levels and percent excess weight loss (%EWL). RESULTS: In 30.8% of all patients, MOSH was present preoperatively. A significant increase of TT was observed postoperatively that led to a complete resolution of hypogonadism within the period observed. Bioavailable testosterone (bTT) and FSH levels significantly increased each month of follow-up after surgery (all P < .01). Levels of 17bE did not change significantly after surgery. The overall change of TT, comparing preoperative and 1-year postoperative TT levels (ΔTT), significantly correlated with %EWL. Changes in TT levels were not affected by the choice of surgical method. CONCLUSIONS: Serum plasma testosterone levels rise significantly after metabolic and bariatric surgery in male patients. The change of testosterone levels seems to play a role in continued weight loss after surgery. This is true irrespective of the surgical method used.

Intrathoracic pouch migration in one-anastomosis gastric bypass with and without hiatoplasty: A 3-dimensional-computed tomography volumetry study.

BACKGROUND: Currently, 4.8% of bariatric operations worldwide are one-anastomosis gastric bypass (OAGB) procedures. If a hiatal hernia is detected in a preoperative gastroscopy, OAGB can be combined with hiatoplasty. Intrathoracic pouch migration (ITM) is common after bypass procedures because the fundus, a natural abutment, is separated from the pouch. OBJECTIVE: The aim of this study was to find out whether OAGB or OAGB combined with hiatoplasty carries a higher risk of ITM and, therefore, also gastroesophageal reflux disease (GERD). SETTING: University hospital. METHODS: Fifty patients (group 1: 25× primary OAGB; group 2: 25× primary OAGB with hiatoplasty) were included in this study. History of weight, GERD, and quality of life were recorded in patient interviews and pouch volume and ITM were evaluated using 3-dimensional-computed tomography volumetry. RESULTS: There were no differences in terms of patient characteristics, history of weight, pouch volume, or quality of life between both groups. ITM was found in group 1 in 60% (n = 15) and group 2 in 76% (n = 19) of all patients (P = .152). The ITM mean length was significantly lower in group 1 with .9 ± 1.1 cm than in group 2 with 1.8 ± 1.2 cm (P = .007). Regarding GERD, there was no difference between both groups; nevertheless, significantly more patients with ITM (38.2%; n = 13) had GERD compared with patients without ITM (6.3%; n = 1). CONCLUSION: In primary OAGB, an additional hiatoplasty was not associated with higher rates of ITM or GERD; nevertheless, the length of ITM was higher after hiatoplasty. If ITM occurs, patients have a risk of developing GERD.

Surgical Technique for Weight Regain after Roux-en-Y Gastric Bypass: Pouch-resizing and the MiniMIZER® Gastric Ring.

Laparoscopic Roux-en-Y Gastric Bypass (RYGB) is a commonly used method in bariatric surgery that leads to sufficient long-term weight loss and consequently to improvement or resolution of obesity-associated diseases. The nadir weight is commonly reached between six months and two years after surgery. Despite this initially good weight loss, weight regain is observed in up to 20% of the patients. Besides intensive dietological evaluation, bariatric re-operation can be an option in these cases. Before the surgical reintervention, an intensive evaluation of the esophagus, pouch, anastomosis, and adjacent small bowel using upper GI-endoscopy and radiological examinations (X-ray and/or 3D-CT volumetry) is mandatory. In patients with a dilated pouch, pouch-resizing with a MiniMIZER® Gastric Ring (Bariatric Solutions GmbH, Stein am Rhein, Switzerland) could be an option to reestablish restriction in the long term. Currently, there is no gold standard for the choice of the weight regain procedure or for the technique used in the procedure itself. This article focuses on the standardized procedure of pouch resizing with implantation of a MiniMIZER® Gastric Ring for the surgical therapy of weight regain due to pouch dilatation and/or dilatation of the gastrojejunostomy and the adjacent small bowel (usually approximately the first 20cm), resulting in a huge neo-stomach after RYGB, as performed at the Medical University of Vienna. Further, indications for revisional surgery for weight regain, mandatory examinations, and recommended conservative therapy options prior to surgery will be described. Next, the fast-track concept and its advantages are explained. Lastly, the surgical procedure, including positioning of the patient, placement of trocars, the intraoperative process, and special advice, is presented. Exact planning of the procedure and postoperative follow-up are indispensable for a further long-term success after weight regain surgery. In conclusion, pouch-resizing and implantation of the MiniMIZER® Gastric Ring represent a practical and effective solution in patients with dilated pouch/anastomosis/adjacent small bowel with weight regain after RYGB, if conservative therapy, including dietitian counseling and new drugs (e.g., Semaglutide), has failed.

Obesity is associated with a higher Torque Teno viral load compared to leanness.

Introduction: Obesity affects a rising proportion of the population and is an important risk factor for unfavorable outcomes in viral disease including severe acute respiratory syndrome coronavirus 2- associated diseases. Torque Teno virus (TTV) is a ubiquitous and apathogenic virus which reflects the immune function of its host. The aim of this study was to investigate the association between obesity and TTV load - an indirect marker of compromised viral immune response. Methods: TTV was quantified by TTV R-GENE® PCR in a total of 89 participants of which 30 were lean (BMI <25 kg/m2) and 59 were obese (BMI >30 kg/m2). For 38 subjects, follow-up was available after bariatric surgery. Results: TTV load was higher in individuals with obesity (median 2.39, IQR: 1.69-3.33 vs. 1.88, IQR 1.08-2.43 log10 copies/mL; p = 0.027). Multivariable linear modeling revealed an independent association between TTV load and obesity. TTV was positively correlated with waist-to-hip ratio and inversely with 25OH vitamin D levels. Interleukin 6 and fasting insulin resistance were confounders of the association between TTV and obesity, while age was an effect modifier. TTV load increased by 87% (95% CI 2-243%) in the year following bariatric surgery. Discussion: A higher TTV load in obese individuals may reflect compromised immune function and thus might serve for risk stratification of unfavorable outcomes during infectious disease, including coronavirus disease 2019, in this population. Our data warrant further analysis of TTV-based risk assessment in obese individuals in the context of infectious disease-associated outcomes.

Fifteen Years after Sleeve Gastrectomy: Gastroscopies, Manometries, and 24-h pH-Metries in a Long-Term Follow-Up: A Multicenter Study.

INTRODUCTION: Sleeve gastrectomy (SG) is the most common bariatric operation with over 340,000 procedures per year. There are only few studies presenting follow-up results >10 years in the literature today. The aim of this study was the objective evaluation of long-term outcomes of at least 15 years after SG in non-converted patients. METHODS: This study (multicenter cross-sectional; university-hospital based) includes all non-converted patients with primary SG before December 2005 at participating bariatric centers. The following methods were used: gastroscopy, esophageal manometry, 24-h pH-metry, and Gastrointestinal Quality of Life Index (GIQLI). RESULTS: After removing converted patients, patients with bariatric procedures before SG, and deceased patients from the cohort, 20 of 53 participants have met the inclusion criteria. Of this group, 55% are suffering from symptomatic gastroesophageal reflux disease (GERD); 45% are without GERD. Esophagitis, hiatal hernias, Barrett's esophagus, and enlarged sleeves were found in 44%, 50%, 13%, and 69% of patients during gastroscopy. Mean lower esophageal sphincter pressure was normal at 20.2 ± 14.1 mm Hg during manometry. Reflux activity in 24 h, number of refluxes, and DeMeester score were increased at 12.9 ± 9.7%, 98.0 ± 80.8, and 55.3 ± 36.3 during 24-h pH-metry. Patients with GERD scored significantly lower in the GIQLI than patients without GERD: 107.6 ± 18.4 versus 127.6 ± 14.4 (p = 0.04). DISCUSSION/CONCLUSION: Fifteen years after primary SG, objective testing has shown that GERD, esophagitis, and Barrett's esophagus are major issues for these patients. Surveillance endoscopies at 5-year intervals in all SG patients and 3-year intervals in patients with Barrett's esophagus are recommended.

Surgical Technique of Single Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy (SADI-S).

Laparoscopic Single Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy (SADI-S) is a bariatric/metabolic procedure that has been gaining popularity in recent years. SADI-S strongly affects the secretion of various gut hormones, adipocytokines and incretins. From a mechanistic point of view, the operation combines malabsorption and restriction, and has been shown to have a long-lasting and significant impact on weight loss and remission of comorbidities. With regard to the technique, first, a Sleeve is created and then the duodenum is tran-sected approximately 3-4cm after the pylorus at the level of the gastroduodenal artery (GDA). Next, 250-300cm of small bowel is measured from the caecum and a hand-sewn duo-deno-ileal anastomosis is performed. The length of the biliopancreatic limb is variable in this procedure. Because of the standardized common limb length in all patients, weight loss is very precise within a low range. Nevertheless, due to the complex hand-sewn anastomosis and the delicacy necessary when handling the duodenum, this procedure should be reserved for experienced bariatric surgeons in specialized centers. This article provides an overview of the standard surgical technique at the Department of Visceral Surgery at the Medical University of Vienna, as well as information about patient selection and pre- and postoperative care.

Brown Adipose Tissue Prevalence Is Lower in Obesity but Its Metabolic Activity Is Intact.

Due to its high metabolic activity, brown adipose tissue (BAT) has become a promising target for the development of novel treatment concepts for metabolic disease. Despite several reports of a negative association between the presence of active BAT and obesity, very little is known about the quantitative and qualitative differences of BAT in lean and obese individuals. Systematic studies directly comparing cold-induced BAT activity in leanness and obesity are currently lacking. Here we studied BAT mass and function in 31 lean and 64 obese men and women. After a standardized cooling protocol using a water-perfused vest, 18F-FDG-positron emission tomography/computed tomography scans were performed, and BAT was delineated using lean body-mass adjusted standardized uptake value (SUV) thresholds in anatomic regions with fat radiodensity. Cold-induced thermogenesis (CIT), a functional readout of BAT activity, was quantified by indirect calorimetry. Active BAT was present in a significantly higher proportion of lean than obese individuals (58% vs. 33%, p=0.019). In these participants with active BAT, however, BAT volume and activity did not differ between leanness and obesity. Accordingly, CIT was similar in both weight groups. BAT metrics were not related to adiposity or total fat mass per se. However, in obese participants a strong negative correlation existed between visceral adipose tissue and BAT volume, 18F-FDG uptake and CIT. In summary, despite a significantly lower prevalence of BAT, the metabolic activity and thermogenic capacity of BAT appears to be still intact in obesity and is inversely associated with visceral fat mass.

Trends of Overweight and Obesity in Male Adolescents: Prevalence, Socioeconomic Status, and Impact on Cardiovascular Risk in a Central European Country.

BACKGROUND: Obesity is one of the most important health-related problems of the twenty-first century. Data on its prevalence in Austria remain scarce. Aim of this study was to determine current trends of overweight and obesity, associated comorbidities and socioeconomic status in all 18-year-old male Austrian citizens, and its potential impact on the demand for bariatric surgery in the future. METHODS: Data from compulsory military conscription examinations in all 18-year-old males from 2003 to 2018 were obtained from the Federal ministry of Defense's database. Measurements of height, weight, and subsequent body mass index (BMI) calculations in 874, 220 adolescents were subdivided into yearly cohorts. Comorbidities, educational status, and nicotine abuse were evaluated. RESULTS: Mean BMI increased from 22.0 ± 3.95 kg/m2 in 2003 to 22.8 ± 4.69 kg/m2 in 2018 (p < 0.001). Overweight and obesity °I-III increased from 15.3%, 4.2%, 1.2%, and 0.4% (2003) to 20.4%, 7.1%, 2.5%, and 0.8% (2018), respectively. Cardiovascular risk, reflected by the waist-to-height ratio, increased significantly over time (p < 0.0001). Additionally, data showed a significant association of nicotine abuse in overweight or obese adolescents (p < 0.0001). Significantly less adolescents with obesity graduated from high school (p < 0.0001). Overall, 25.7% of adolescents with obesity were considered ineligible for military service. CONCLUSIONS: BMI and cardiovascular risk steadily increased over the last 15 years in Austrian male adolescents. A significant shift from normal weight to overweight was observed, while higher obesity classes doubled over this observational period. This study also revealed a significant association of BMI and lower educational status. Trends of overweight and obesity in male adolescents: prevalence, socio-economic status and impact on cardiovascular risk in a central European country.

Conversion from one-anastomosis gastric bypass to Roux-en-Y gastric bypass: when and why-a single-center experience of all consecutive OAGB procedures.

BACKGROUND: One-anastomosis gastric bypass (OAGB) is a well-established treatment method in patients with morbid obesity. Its long-term impact on de novo reflux, anastomotic complications, and malnutrition needs further evaluation. Roux-en-Y gastric bypass (RYGB) is a technically feasible procedure in revisional bariatric surgery. This study presents our institutional data on conversion from OAGB to RYGB. OBJECTIVE: To determine the reasons for conversion, preoperative endoscopic findings, and feasibility of revisional bariatric surgery after OAGB. SETTING: University hospital in Austria METHODS: Retrospective analysis of a prospectively fed database. All patients undergoing OAGB between January 2012 and December 2019 were included. Screening was carried out for all patients needing conversion to RYGB. Percent total weight loss, percent excess weight loss, time to conversion, postoperative complications, and reasons for conversion were assessed. RESULTS: Eighty-two of 1,025 patients who underwent OAGB were converted laparoscopically to RYGB. Seven patients were converted early because of anastomotic/gastric tube leakage. Median time to late conversion was 29.1 ± 24.3 months, mean percent excess weight loss was 86.6% ± 33.1% and percent total weight loss was 35.1% ± 13.5%. Forty-two patients were converted because of reflux, 11 because of persistent marginal ulcers, 10 because of anastomotic stenosis, 9 because of malnutrition, and 3 because of weight regain. Seven patients showed Barrett's metaplasia in biopsies at the gastroesophageal junction before conversion. CONCLUSION: Laparoscopic conversion from OAGB to RYGB is technically feasible with a moderate rate of postoperative complications. Severe (bile) reflux is a serious long-term complication after OAGB, with 4.1% of patients needing conversion to RYGB. Endoscopy after OAGB in patients showing clinical symptoms of gastroesophageal reflux disease is strongly advised to detect underlying pathologic changes.

Impact of metabolic surgery on cost and long-term health outcome: a cost-effectiveness approach.

BACKGROUND: The increase in obesity has become a major public health concern. Morbid obesity is associated with co-morbidities, reduced quality-of-life, and death. Metabolic surgery (MS) is the most effective treatment for obesity. OBJECTIVES: The aim of this study was to evaluate the costs and outcomes of MS compared with no surgery in patients with a body mass index ≥30 kg/m2. SETTING: Health care system, Austria METHODS: A total of 177 patients who underwent MS were documented retrospectively, based on the hospital records of 2 specialized centers in Austria, over a 1-year period. At baseline 26.0% of patients exhibited type 2 diabetes (T2D), 52.5% cardiovascular disease (CVD), 23.2% hyperlipidemia, and 23.7% depression. Following the observation period, a Markov chain simulation model was developed to analyze the long-term consequences of T2D, including diabetic complications, CVD, hyperlipidemia, depression, non-alcoholic steatohepatitis (NASH), myocardial infarction, and stroke, over a total of 20 years. Direct medical costs were expressed in 2017 euros from the payer's perspective. Quality-adjusted life years (QALYs), life years (LYs), and costs were discounted. RESULTS: MS led to costs of €40,427 and 9.58 QALYs (15.58 LYs) per patient over 20 years. No MS was associated with €64,819 and 6.33 QALYs (13.92 LYs). Total cost-savings amounted to €24,392, which offset the cost of the procedure including re-operations. Over 20 years MS saved -6.7 patient-years per patient with T2D, -5.8 patient-years with CVD, -1.5 patient-years with hyperlipidemia, -1.8 patient-years with depression, and -3.8 patient-years with NASH. CONCLUSION: MS is associated with substantial savings in long-term costs, expected health benefits, and reduced onset of complications. MS significantly increases quality of life.

Active Brown Adipose Tissue is Associated With a Healthier Metabolic Phenotype in Obesity.

Obesity is associated with increasing cardiometabolic morbidity and mortality worldwide. Not everyone with obesity, however, develops metabolic complications. Brown adipose tissue (BAT) has been suggested as a promoter of leanness and metabolic health. To date, little is known about the prevalence and metabolic function of BAT in subjects with severe obesity, a population at high cardiometabolic risk. In this cross-sectional study, we included 40 individuals with WHO class II-III obesity (BMI ≥ 35 kg/m2). Employing a 150-minute personalized cooling protocol and 18F-fluorodeoxyglucose positron emission tomography/computed tomography, cold-activated BAT was detectable in 14 (35%) of the participants. Cold-induced thermogenesis was significantly higher in participants with detectable BAT compared to those without. Notably, individuals with obesity and active BAT had 28.8% lower visceral fat mass despite slightly higher total fat mass compared to those without detectable BAT 18F-FDG uptake. This was accompanied by lower insulin resistance and systemic inflammation and improved NAFLD parameters, all adjusted for age, sex, and percent body fat. Contrary to previous assumptions, we show here that a significant fraction of individuals with severe obesity has active BAT. We found that decreased BAT 18F-FDG uptake was not associated with adiposity per se but with higher visceral fat mass. In summary, active BAT is linked to a healthier metabolic phenotype in obesity.

Accuracy of non-invasive liver stiffness measurement and steatosis quantification in patients with severe and morbid obesity.

BACKGROUND: Vibration controlled transient elastography (VCTE) and controlled attenuation parameter (CAP™) have shown reliable performance predicting fibrosis and steatosis in normal- to overweight patients but have not been validated in severe to morbid obesity. This study aimed at determining the accuracy of VCTE, CAP™ and the composite score FibroScan-AST (FAST) in patients with a body mass index (BMI) of ≥35 kg/m2. METHODS: Patients scheduled for bariatric-metabolic surgery underwent preoperative VCTE/CAP™ measurement, and intraoperative liver biopsy. The feasibility and accuracy of VCTE, CAP™ and the composite score FAST were retrospectively analysed to evaluate fibrosis, steatosis and active fibrotic non-alcoholic steatohepatitis [NASH + non-alcoholic fatty liver disease (NAFLD) activity score ≥4 + fibrosis grade ≥2] using per protocol (PP) and intent to diagnose (ITD) calculation. RESULTS: In total, 170 patients (median BMI 44.4 kg/m2) were included in the study. Liver biopsy showed NASH, simple steatosis, and normal livers in 60.6% (n=103), 28.8% (n=49), and 10.6% (n=18), respectively. VCTE and CAP™ delivered reliable results in 90.6% (n=154/170) and 90.5% (n=134/148). The AUC (PP) of VCTE, CAP™, and FAST were 0.687 (≥F2), 0.786 (≥F3), 0.703 (≥S2), 0.738 (S3), and 0.780 (active fibrotic NASH). The AUC increased to 0.742 (≥F2), 0.842 (≥F3), 0.712 (≥S2), 0.780 (S3), and 0.836 (active fibrotic NASH) in patients below the median BMI of 44.4 kg/m2. CONCLUSIONS: VCTE, CAP™ and FAST show acceptable accuracy for the detection of fibrosis, steatosis and NASH in a real-life cohort of patients with obesity. Accuracy improves in patients with a BMI <44.4 kg/m2.

Surgical Technique of Diverted One-Anastomosis Gastric Bypass.

Laparoscopic diverted one-anastomosis gastric bypass (D-OAGB) is a bariatric procedure combining the principles of restriction, malabsorption, and other factors to induce weight loss. It is achieved by creating a narrow, long gastric pouch and bypassing a part of the small bowel (biliopancreatic limb). D-OAGB was first described by Dr. Ribero in 2013 and is technically a variation of the very heterogeneous group of Roux-en-Y gastric bypass operations. There are different technical variants to perform D-OAGB and to organize pre- and postoperative care. The following article is based on the approach to bariatric surgery as taken at the Department of General Surgery at the Medical University of Vienna. This article focuses on patient preparation before bariatric/metabolic surgery with mandatory and optional preoperative examinations to find the surgical procedure best suited for each individual patient and to decrease the patient's risk. The surgical technique of D-OAGB itself, including positioning of the patient and related technical highlights, as well as the specifics of the postoperative course, are described. D-OAGB is an effective procedure for patients with symptomatic gastroesophageal reflux for adequate weight loss and remission of comorbidities with a low risk of malnutrition. For D-OAGB to be successful, important technical steps, such as creating a narrow, long pouch, exact length of the biliopancreatic and alimentary limb, and additional hiatoplasty (if necessary), should be taken. In terms of the postoperative course, regular checkups are vital to ensure desirable outcome in the long-term follow up and early detection of adverse developments.

Characterization of endogenous bile acid composition in individuals with cold-activated brown adipose tissue.

INTRODUCTION: Bile acid signaling has been suggested to promote BAT activity in various experimental models. However, little is known if and how physiologic bile acid metabolism is linked to BAT function in humans. Here we investigated the association between BAT activity and circulating bile acid concentrations in lean and obese individuals. METHODS: BAT 18F-fluorodeoxyglucose uptake was measured after a standardized cooling protocol by positron emission tomography/computed tomography. Cold-induced thermogenesis was assessed by indirect calorimetry. Fasting bile acid concentrations were determined by high performance liquid chromatography-high-resolution mass spectrometry. RESULTS: In a cohort of 24 BAT-negative and 20 BAT-positive individuals matched by age, sex, and body mass index, circulating bile acid levels were similar between groups except for higher ursodeoxycholic acid and a trend towards a lower 12α-OH/non-12α-OH bile acid ratio in lean participants with active BAT compared to those without. Moreover, the 12α-OH/non-12α-OH ratio, a marker of CYP8B1 activity, correlated negatively with BAT volume and activity. CONCLUSION: Fasting concentrations of major bile acids are not associated with cold-induced BAT activity in humans. However, the inverse association between BAT activity and 12α-OH/non-12α-OH ratio may suggest CYP8B1 as a potential new target in BAT function and warrants additional investigation.

Sex differences in brown adipose tissue activity and cold-induced thermogenesis.

INTRODUCTION: Brown adipose tissue (BAT) is suggested to exhibit a sexual dimorphism and thus contributes to the observed sex differences in cardiometabolic risk observed between women and men. Clinical data supporting this hypothesis are however scarce. The aim of this study was to investigate the relationship between BAT activity and sex using positron emission tomography (PET) - the current gold-standard for BAT quantification. METHODS: In this study, we included 95 subjects with a wide BMI range (20-55 kg/m2) aged from 18 to 50 years. Avoiding shivering, participants were cooled with a water-perfused vest to achieve adequate BAT activation. BAT activity was determined by 18F-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT). Cold-induced thermogenesis (CIT) was quantified by indirect calorimetry. RESULTS: BAT was present in 44.6% of pre-menopausal women and in 35.9% of men (p = 0.394). CIT was significantly higher in women (p = 0.024). Estradiol levels were positively associated with CIT independent of age, sex, body fat and other sex hormones (b = 0.360, p = 0.016). In women, CIT decreased during the menstrual cycle, with lower levels in the luteal phase similar to median concentrations in men. CONCLUSION: The prevalence of cold-activated BAT is slightly but non-significantly higher in pre-menopausal women than men. CIT is increased in females and independently associated with estradiol, suggesting that sex hormones may play a role in different thermogenic responses between men and women.

Fifteen Years After Sleeve Gastrectomy: Weight Loss, Remission of Associated Medical Problems, Quality of Life, and Conversions to Roux-en-Y Gastric Bypass-Long-Term Follow-Up in a Multicenter Study.

PURPOSE: Since 2014, sleeve gastrectomy (SG) has been the most frequently performed bariatric-metabolic operation worldwide (2018: 386,096). There are only a few studies reporting a long-term follow-up (up to 11 years) available today. The aim of this study was to evaluate the long-term outcome of SG with a follow-up of at least 15 years regarding weight loss, remission of associated medical problems (AMP), conversions, and quality of life (QOL). SETTING: Multicenter cross-sectional study; university hospital. METHODS: This study includes all patients who had SG before 2005 at the participating bariatric centers. History of weight, AMP, conversions, and QOL were evaluated by interview at our bariatric center. RESULTS: Fifty-three patients met the inclusion criteria of a minimal follow-up of 15 years. Weight and body mass index at the time of the SG were 136.8kg and 48.7kg/m2. Twenty-six patients (49.1%) were converted to Roux-en-Y gastric bypass (RYGB) for weight regain and gastroesophageal reflux within the follow-up period. Total weight loss after 15 years was 31.5% in the non-converted group and 32.9% in the converted group. Remission rates of AMP and QOL were stable over the follow-up period. CONCLUSION: Fifteen years after SG, a stable postoperative weight was observed at the cost of a high conversion rate. Patients converted to RYGB were able to achieve further weight loss and preserve good remission rates of AMP. SG in patients without the need of a conversion to another bariatric-metabolic procedure may be considered effective. Careful preoperative patient selection is mandatory when performing SG.

Bariatric Surgery-How Much Malabsorption Do We Need?-A Review of Various Limb Lengths in Different Gastric Bypass Procedures.

The number of obese individuals worldwide continues to increase every year, thus, the number of bariatric/metabolic operations performed is on a constant rise as well. Beside exclusively restrictive procedures, most of the bariatric operations have a more or less malabsorptive component. Several different bypass procedures exist alongside each other today and each type of bypass is performed using a distinct technique. Furthermore, the length of the bypassed intestine may differ as well. One might add that the operations are performed differently in different parts of the world and have been changing and evolving over time. This review evaluates the most frequently performed bariatric bypass procedures (and their variations) worldwide: Roux-en-Y Gastric Bypass, One-Anastomosis Gastric Bypass, Single-Anastomosis Duodeno-Ileal Bypass + Sleeve Gastrectomy, Biliopancreatic Diversion + Duodenal Switch and operations due to weight regain. The evaluation of the procedures and different limb lengths focusses on weight loss, remission of comorbidities and the risk of malnutrition and deficiencies. This narrative review does not aim at synthesizing quantitative data. Rather, it provides a summary of carefully selected, high-quality studies to serve as examples and to draw tentative conclusions on the effects of the bypass procedures mentioned above. In conclusion, it is important to carefully choose the procedure and small bowel length excluded from the food passage suited best to each individual patient. A balance has to be achieved between sufficient weight loss and remission of comorbidities, as well as a low risk of deficiencies and malnutrition. In any case, at least 300 cm of small bowel should always remain in the food stream to prevent the development of deficiencies and malnutrition.