Background:The outcomes of liver surgery worldwide remain unknown. The true population-based outcomes are likely different to those vastly reported that reflect the activity of highly specialized academic centers. The aim of this study was to measure the true worldwide practice of liver surgery and associated outcomes by recruiting from centers across the globe. The geographic distribution of liver surgery activity and complexity was also evaluated to further understand variations in outcomes.Methods:LiverGroup.org was an international, prospective, multicenter, cross-sectional study following the Global Surgery Collaborative Snapshot Research approach with a 3-month prospective, consecutive patient enrollment within January-December 2019. Each patient was followed up for 90 days postoperatively. All patients undergoing liver surgery at their respective centers were eligible for study inclusion. Basic demographics, patient and operation characteristics were collected. Morbidity was recorded according to the Clavien-Dindo Classification of Surgical Complications. Country-based and hospital-based data were collected, including the Human Development Index (HDI). (NCT03768141).Results:A total of 2159 patients were included from six continents. Surgery was performed for cancer in 1785 (83%) patients. Of all patients, 912 (42%) experienced a postoperative complication of any severity, while the major complication rate was 16% (341/2159). The overall 90-day mortality rate after liver surgery was 3.8% (82/2,159). The overall failure to rescue rate was 11% (82/ 722) ranging from 5 to 35% among the higher and lower HDI groups, respectively.Conclusions:This is the first to our knowledge global surgery study specifically designed and conducted for specialized liver surgery. The authors identified failure to rescue as a significant potentially modifiable factor for mortality after liver surgery, mostly related to lower Human Development Index countries. Members of the LiverGroup.org network could now work together to develop quality improvement collaboratives.

INTRODUCTION Nonalcoholic fatty liver disease (NAFLD) is a common liver abnormality, but its nonin-vasive diagnosis in patients with severe obesity remains difficult.OBJECTIVES Our aim was to investigate the usefulness of the ultrasound-based hepatorenal index (HRI) technique and 2 biomarker-based methods, including the hepatic steatosis index (HSI) and NAFLD logit score for the diagnosis of NAFLD in patients referred for bariatric surgery.PATIENTS AND METHODS A total of 162 patients, including 106 with NAFLD, admitted for bariatric surgery participated in the study. Fat fraction level and the presence of NAFLD were determined using surgical liver biopsy. Each patient underwent liver ultrasound examination and blood tests to determine the HRI, HSI, and NAFLD logit score.RESULTS For the NAFLD diagnosis, the HRI, HSI, and NAFLD logit score techniques achieved areas under the receiver operating characteristic curves of 0.879, 0.577, and 0.825, respectively. The Spearman cor-relation coefficients between the liver fat fraction values and the HRI, HSI, and NAFLD logit score were equal to 0.695, 0.215, and 0.595, respectively. The optimal cutoff values for the NAFLD diagnosis for the HRI, HSI, and NAFLD logit score were equal to 1.12, 56.1, and 0.59, respectively, and significantly differed from the cutoff values reported for the general population in the literature.CONCLUSIONS Our study confirmed the usefulness of only 2 out of 3 techniques, the HRI and the NAFLD logit score for the diagnosis of NAFLD in patients with severe obesity. The methods designed for the general population require different cutoff values to achieve accurate performance in patients with severe obesity.

Background The severity of liver steatosis is modulated by the PNPLA3 p.I148M, TM6SF2 rs58542926 and MBOAT7 rs641738 polymorphisms. Recently two genetic variants, namely MARC1 rs2642438 and HSD17B13 rs72613567, were shown to have protective effects in patients with chronic liver diseases. Here we analyse these variants in patients undergoing bariatric surgery.

The severity of hepatic steatosis is modulated by genetic variants, such as patatin-like phospholipase domain containing 3 (PNPLA3) rs738409, transmembrane 6 superfamily member 2 (TM6SF2) rs58542926, and membrane-bound O-acyltransferase domain containing 7 (MBOAT7) rs641738. Recently, mitochondrial amidoxime reducing component 1 (MTARC1) rs2642438 and hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) rs72613567 polymorphisms were shown to have protective effects on liver diseases. Here, we evaluate these variants in patients undergoing bariatric surgery. A total of 165 patients who underwent laparoscopic sleeve gastrectomy and intraoperative liver biopsies and 314 controls were prospectively recruited. Genotyping was performed using TaqMan assays. Overall, 70.3% of operated patients presented with hepatic steatosis. NASH (non-alcoholic steatohepatitis) was detected in 28.5% of patients; none had cirrhosis. The increment of liver fibrosis stage was associated with decreasing frequency of the MTARC1 minor allele (p = 0.03). In multivariate analysis MTARC1 was an independent protective factor against fibrosis ≥ 1b (OR = 0.52, p = 0.03) and ≥ 1c (OR = 0.51, p = 0.04). The PNPLA3 risk allele was associated with increased hepatic steatosis, fibrosis, and NASH (OR = 2.22, p = 0.04). The HSD17B13 polymorphism was protective against liver injury as reflected by lower AST (p = 0.04) and ALT (p = 0.03) activities. The TM6SF2 polymorphism was associated with increased ALT (p = 0.04). In conclusion, hepatic steatosis is common among patients scheduled for bariatric surgery, but the MTARC1 and HSD17B13 polymorphisms lower liver injury in these individuals.

Supplemental Digital Content is available in the text Objective: To compare the early results of mass and layered closure of upper abdominal transverse incisions. Summary of Background Data: Contrary to midline incisions, data on closure of transverse abdominal incisions are lacking. Methods: This is the first analysis of a randomized controlled trial primarily designed to compare mass with layered closure of transverse incisions with respect to incisional hernias. Patients undergoing laparotomy through upper abdominal transverse incisions were randomized to either mass or layered closure with continuous sutures. Incisional surgical site infection (incisional-SSI) was the primary end-point. Secondary end-points comprised suture-to-wound length ratio (SWLR), closure duration, and fascial dehiscence (clinicatrials.gov NCT03561727). Results: A total of 268 patients were randomized to either mass (n=134) or layered (n=134) closure. Incisional-SSIs occurred in 24 (17.9%) and 8 (6.0%) patients after mass and layered closure, respectively (P =0.004), with crude odds ratio (OR) of 0.29 [95% confidence interval (95% CI) 0.13–0.67; P =0.004]. Layered technique was independently associated with fewer incisional-SSIs (OR: 0.29; 95% CI 0.12–0.69; P =0.005). The number needed to treat, absolute, and relative risk reduction for layered technique in reducing incisional-SSIs were 8.4 patients, 11.9%, and 66.5%, respectively. Dehiscence occurred in one (0.8%) patient after layered closure and in two (1.5%) patients after mass closure (P >0.999). Median SWLR were 8.1 and 5.6 (P <0.001) with median closure times of 27.5 and 25.0 minutes (P =0.044) for layered and mass closures, respectively. Conclusions: Layered closure of upper abdominal transverse incisions should be preferred due to lower risk of incisional-SSIs and higher SWLR, despite clinically irrelevant longer duration.

Objective: To compare the early results of mass and layered closure of upper abdominal transverse incisions. Summary of Background Data: Contrary to midline incisions, data on closure of transverse abdominal incisions are lacking. Methods: This is the first analysis of a randomized controlled trial primarily designed to compare mass with layered closure of transverse incisions with respect to incisional hernias. Patients undergoing laparotomy through upper abdominal transverse incisions were randomized to either mass or layered closure with continuous sutures. Incisional surgical site infection (incisional-SSI) was the primary end-point. Secondary end-points comprised suture-to-wound length ratio (SWLR), closure duration, and fascial dehiscence (clinicatrials.gov NCT03561727). Results: A total of 268 patients were randomized to either mass (n=134) or layered (n=134) closure. Incisional-SSIs occurred in 24 (17.9%) and 8 (6.0%) patients after mass and layered closure, respectively (P =0.004), with crude odds ratio (OR) of 0.29 [95% confidence interval (95% CI) 0.13-0.67; P =0.004]. Layered technique was independently associated with fewer incisional-SSIs (OR: 0.29; 95% CI 0.12-0.69; P =0.005). The number needed to treat, absolute, and relative risk reduction for layered technique in reducing incisional-SSIs were 8.4 patients, 11.9%, and 66.5%, respectively. Dehiscence occurred in one (0.8%) patient after layered closure and in two (1.5%) patients after mass closure (P >0.999). Median SWLR were 8.1 and 5.6 (P <0.001) with median closure times of 27.5 and 25.0 minutes (P =0.044) for layered and mass closures, respectively. Conclusions: Layered closure of upper abdominal transverse incisions should be preferred due to lower risk of incisional-SSIs and higher SWLR, despite clinically irrelevant longer duration.

Background The patients with nonalcoholic fatty liver disease demonstrate an increased cardiovascular risk. The adverse influence of liver abnormalities on cardiac function are among many postulated mechanisms behind this association. The aim of the study was to evaluate cardiac morphology and function in patients with morbid obesity referred for bariatric surgery with liver biopsy. Methods and Results We evaluated with echocardiography 171 consecutive patients without known cardiac disease (median age 42 [interquartile range, 37–48] years, median body mass index 43.7 [interquartile range, 41.0–47.5], 67% female patients. Based on the liver biopsy results, there were 44 patients with nonalcoholic steatohepatitis (NASH), 69 patients with isolated steatosis, and 58 patients without steatosis. Patients with NASH demonstrated signs of left ventricular concentric remodeling and hyperdynamic circulation, including indexed left ventricular end‐diastolic diameter [cm/m2]: NASH 1.87 [0.22]; isolated steatosis 2.03 [0.33]; without steatosis 2.01 [0.19], P=0.001; relative wall thickness: NASH 0.49±0.05, isolated steatosis 0.47±0.06, without steatosis 0.46±0.06, P=0.011; cardiac index [L/m2]: NASH 3.05±0.54, isolated steatosis 2.80±0.44, without steatosis 2.79±0.50, P=0.013. After adjustment for sex, age, blood pressure, and heart rate, most of the measures of the left ventricular systolic and diastolic function, left atrial size, right ventricular function, and right ventricular size did not differ between groups. Conclusions In a group of patients with extreme obesity, NASH was associated with left ventricular concentric remodeling and hyperdynamic circulation. Increased cardiac output in NASH may represent an additional risk factor for incident cardiovascular events in this population.

Purpose Bariatric surgery is no longer considered only as a weight loss surgery but also a way of treating obesity-related comorbidities such as type 2 diabetes mellitus (T2DM). Short-term T2DM remissions in patients undergoing laparoscopic sleeve gastrectomy (LSG) have been shown, but there are very few reports on the mid-term results. We aimed to assess the remission rate of T2DM in obese patients after LSG throughout 5-year follow-up. Materials and Methodology We performed a retrospective multicenter cohort analysis of 240 patients who underwent LSG. We assessed the remission rate of T2DM 1 year and 5 years after surgery. Results Forty-six percent of patients achieved T2DM remission 5 years after LSG. The remission group had better weight loss results (median% of total weight loss 5 years after: 30.1% (22.9–37.0) vs 23.0% (13.7–30.2), p < 0.001) and were significantly younger than the no remission group (43 (38–52) vs 52 (44–58) years, p < 0.001). Duration of T2DM was significantly shorter (2 (1–5) vs 5 (3–10) years, p < 0.001) with less insulin requirement and less diabetes-related complications (7.2% vs 19.8%, p < 0.001) and significantly lower median DiaRem score (4.0 (IQR 2.0–6.0) vs 12.0 (IQR 5.0–16.0), p < 0.001). Preoperative body mass index (BMI) had no effect on remission. Conclusions Our study suggests that diabetes remission after laparoscopic sleeve gastrectomy occurs frequently, and in the 5-year follow-up, it may remain at the level of 46%. We identified the age of patients, duration, and severity of T2DM as factors affecting mid-term diabetes remission. Nevertheless, further well-designed trials are needed to support our findings.

Convolutional neural networks (CNNs) have achieved remarkable success in medical image analysis tasks. In ultrasound (US) imaging, CNNs have been applied to object classification, image reconstruction and tissue characterization. However, CNNs can be vulnerable to adversarial attacks, even small perturbations applied to input data may significantly affect model performance and result in wrong output. In this work, we devise a novel adversarial attack, specific to ultrasound (US) imaging. US images are reconstructed based on radio-frequency signals. Since the appearance of US images depends on the applied image reconstruction method, we explore the possibility of fooling deep learning model by perturbing US B-mode image reconstruction method. We apply zeroth order optimization to find small perturbations of image reconstruction parameters, related to attenuation compensation and amplitude compression, which can result in wrong output. We illustrate our approach using a deep learning model developed for fatty liver disease diagnosis, where the proposed adversarial attack achieved success rate of 48%.

Background and aims: Patients with non-alcoholic fatty liver disease are characterized by increased aortic stiffness, but it is unclear whether this is related to non-alcoholic fatty liver disease itself or concomitant metabolic syndrome components, including hypertension and diabetes. Previous studies were methodologically limited by ultrasound-based assessment of liver steatosis or performing liver biopsy in patients with more severe disease. Therefore, we prospectively measured aortic pulse wave velocity (aPWV) in non-selected obese subjects admitted for bariatric surgery with liver biopsy, allowing assessment of the association between aortic stiffness and biopsy-confirmed liver steatosis. Methods: We evaluated 120 consecutive severely obese patients (79 females; mean age 42 +/- 10 years, mean body mass index 45.0 +/- 5.3 kg/m(2)) without cardiac disease or alcohol-induced liver disease, who were admitted for bariatric surgery. The presence or absence of liver steatosis was defined by wedge liver biopsy. aPWV was measured with the Doppler method at the time of preoperative transthoracic echocardiography. Results: Based on liver biopsy results, 82 patients (68%) had liver steatosis and 38 (32%) had no steatosis. Univariate linear regression analysis showed that age, mean arterial pressure, liver steatosis, heart rate, female gender, and diabetes were significantly associated with aPWV. However, only age, mean arterial pressure, heart rate, and diabetes remained significant in the multivariate model (p <= 0.001). Conclusions: We found no independent association between biopsy-confirmed liver steatosis and aortic stiffness measured by Doppler aPWV in morbidly obese individuals. Aortic stiffness in these subjects is related to comorbidities and not to non-alcoholic fatty liver disease itself.

IntroductionRoux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are the two most frequently performed bariatric operations. These two types of metabolic surgery alter the anatomy and function of digestive tract producing significant weight loss in morbidly obese patients but may lead to malnutrition.AimAnalysis of incidence and severity of malnutrition after bariatric surgery in patients submitted to RYGB or LSG during 12 months of follow-up.Material and MethodsRetrospective study of 98 patients after RYGB (n=47) or LSG (n=51) assessed for nutritional deficiencies during 12 months after surgery was conducted. The differences in body mass index (BMI) and blood tests including erythrocytes, haemoglobin, total protein, albumin, iron, ferritin, transferrin, vitamin B12, folic acid, calcium and phosphorus concentrations were compared between groups before the operations and at 1 and 12 months.ResultsNutritional deficiencies were common before surgery with prevalence up to 19.6% for albumin in the LSG group. Median preoperative BMI levels and albumin concentrations were higher in the RYGB group compared to the LSG group, but there was no difference in percent excess weight loss (%EWL) at 1 and 12 months between LSG and RYGB. One month after LSG erythrocyte count, haemoglobin, iron, ferritin and transferrin levels were significantly higher than in the RYGB group. These differences subsided at 12 months. At 12 months, only the prevalence of vitamin B-12 deficiency was significantly higher in the RYGB group.ConclusionBoth RYGB and LSG lead to nutritional deficiencies despite different properties of operations and similar %EWL during follow-up.

PurposeThe nonalcoholic fatty liver disease is the most common liver abnormality. Up to date, liver biopsy is the reference standard for direct liver steatosis quantification in hepatic tissue samples. In this paper we propose a neural network-based approach for nonalcoholic fatty liver disease assessment in ultrasound.MethodsWe used the Inception-ResNet-v2 deep convolutional neural network pre-trained on the ImageNet dataset to extract high-level features in liver B-mode ultrasound image sequences. The steatosis level of each liver was graded by wedge biopsy. The proposed approach was compared with the hepatorenal index technique and the gray-level co-occurrence matrix algorithm. After the feature extraction, we applied the support vector machine algorithm to classify images containing fatty liver. Based on liver biopsy, the fatty liver was defined to have more than 5% of hepatocytes with steatosis. Next, we used the features and the Lasso regression method to assess the steatosis level.ResultsThe area under the receiver operating characteristics curve obtained using the proposed approach was equal to 0.977, being higher than the one obtained with the hepatorenal index method, 0.959, and much higher than in the case of the gray-level co-occurrence matrix algorithm, 0.893. For regression the Spearman correlation coefficients between the steatosis level and the proposed approach, the hepatorenal index and the gray-level co-occurrence matrix algorithm were equal to 0.78, 0.80 and 0.39, respectively.ConclusionsThe proposed approach may help the sonographers automatically diagnose the amount of fat in the liver. The presented approach is efficient and in comparison with other methods does not require the sonographers to select the region of interest.

Background This report presents a case of a 57- year old female with advanced Hepatic Alveolar Echinococcosis causing a secondary Budd-Chiari Syndrome due to infiltration of the suprahepatic inferior vena cava treated successfully by liver transplantation. Case presentation A temporary veno-venous bypass was introduced, but a typical end to end cavo-caval anastomosis wasn’t possible in this case. In order to access a disease free part of the inferior vena cava, an oval window of the diaphragm was excised, providing communication between the peritoneum and pericardium. A vascular clamp was placed onto the right atrium which allowed for an atrial-caval anastomosis. The remainder of hepatectomy was performed in a conventional manner. In the post-operative period and during the 18 month follow-up there were no complications. The patient remains in good general condition with optimal graft function. Conclusions A hepato-atrial anastomosis with a pericardial-peritoneum window during liver transplantation is feasible and extends the curability potential for patients with advanced Hepatic Alveolar Echinococcosis considered for liver transplantation.

Objectives: The aim of the study was to compare the influence of sleeve gastrectomy (SG) versus Roux-en-Y gastric bypass (RYGB) on liver function in bariatric patients with non-alcoholic fatty liver disease (NAFLD) in a randomized clinical trial (NCT01806506). Background: Rapid weight loss and malabsorption after bariatric surgery in patients with NAFLD or steatohepatitis (NASH) may impair liver function. Methods: Sixty-six morbidly obese patients randomized to SG or RYGB were included in a secondary outcome analysis. Intraoperative liver biopsies were categorized with NAFLD Activity Score (NAS) and liver function tests were done before surgery and after 1, 6 and 12 months. Results: NASH was present in 54.5% RYGB and 51.5% SG patients (P > 0.05). At 12 months excess weight loss was 68.7 ± 19.7% after SG and 62.8 ± 18.5% after RYGB (P > 0.05). At 1 month international normalized ratio (INR) increased after RYGB (0.98 ± 0.05 vs 1.14 ± 0.11; P < 0.05) and SG (0.99 ± 0.06 vs 1.04 ± 0.06; P < 0.05), RYGB induced significantly greater increase in INR in the whole group and NASH patients than SG. After RYGB albumin decreased at 1 month (41.2 ± 2.7 vs 39.0 ± 3.2 g/L; P < 0.05). At 12 months, INR and albumin returned to baseline. At 12 months in NASH group, SG induced significant improvement in aspartate aminotransferase (32.4 ± 17.4 vs 21.5 ± 6.9U/L), alanine aminotransferase (39.9 ± 28.6U/L vs 23.8 ± 14.1U/L), gamma-glutamyl transpeptidase (34.3 ± 16.6 vs 24.5 ± 16.8U/L), and lactate dehydrogenase (510.8 ± 33 vs 292.4 ± 29). Variables predictive of INR change after 1 month included operation type, NAS ≥ 5, bilirubin, body mass index, hemoglobin A1C, and dyslipidemia. Conclusions: Patients with NASH undergoing RYGB are more susceptible to early transient deterioration of liver function than after SG.

Adipokines are cytokines that presumably connect the pathologies of metabolic syndrome. One of the adipokines is resistin, the role of which in insulin resistance, obesity, and non-alcoholic fatty liver disease (NAFLD) needs to be determined. Liver biopsy specimens were obtained intraoperatively from 214 obese patients. Histological assessment was based on NAFLD activity score according to Kleiner. Statistical analysis involved semi-quantitive immunohistochemistry assessment of resistin staining and: NAFLD status in obese patients compared with a non-obese control group, selected clinical data (age, sex, body mass index - BMI), selected biochemical data, comorbidities (hypertension, type 2 diabetes mellitus, dyslipidaemia), and metformin treatment in patients with type 2 diabetes mellitus. Resistin expression was observed in the histiocytes of inflammatory infiltrate, Kupffer cells, and histiocytes surrounding the hepatocytes with steatosis. There was a positive correlation between the total expression of resistin and: (1) NAFLD advancement (NAFLD Activity Score- NAS), (2) AST, ALT, BMI, glucose, insulin, Homeostasis Model Assessment (HOMA), LDH, GGT, triglycerides (TG), and glycated haemoglobin (HbA1c). Resistin expression was more intense in patients with type 2 diabetes mellitus and dyslipidaemia and less intense in the control group. Resistin probably plays a role in the pathogenesis of hepatic insulin resistance and aggravates pathologic changes in the liver of patients with NAFLD.