The transcription factor ZNF469 regulates collagen production in liver fibrosis.

Non-alcoholic fatty liver disease (NAFLD) - characterized by excess accumulation of fat in the liver - now affects one third of the world's population. As NAFLD progresses, extracellular matrix components including collagen accumulate in the liver causing tissue fibrosis, a major determinant of disease severity and mortality. To identify transcriptional regulators of fibrosis, we computationally inferred the activity of transcription factors (TFs) relevant to fibrosis by profiling the matched transcriptomes and epigenomes of 108 human liver biopsies from a deeply-characterized cohort of patients spanning the full histopathologic spectrum of NAFLD. CRISPR-based genetic knockout of the top 100 TFs identified ZNF469 as a regulator of collagen expression in primary human hepatic stellate cells (HSCs). Gain- and loss-of-function studies established that ZNF469 regulates collagen genes and genes involved in matrix homeostasis through direct binding to gene bodies and regulatory elements. By integrating multiomic large-scale profiling of human biopsies with extensive experimental validation we demonstrate that ZNF469 is a transcriptional regulator of collagen in HSCs. Overall, these data nominate ZNF469 as a previously unrecognized determinant of NAFLD-associated liver fibrosis.

American Society for Metabolic and Bariatric Surgery 2022 estimate of metabolic and bariatric procedures performed in the United States.

BACKGROUND: Metabolic and bariatric surgery (MBS), despite being the most effective durable treatment for obesity, remains underused as approximately 1% of all qualified patients undergo surgery. The American Society for Metabolic and Bariatric Surgery established a Numbers Taskforce to specify the annual rate of obesity treatment interventions utilization and to determine if patients in need are receiving appropriate treatment. OBJECTIVE: To provide the best estimated number of metabolic and bariatric procedures being performed in the United States in 2022. SETTING: United States. METHODS: We reviewed data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program and National Surgical Quality Improvement Program. In addition, data from industry and state databases were used to estimate activity at non-accredited centers. Data from 2022 were compared mainly with data from the previous 2 years. RESULTS: Compared with 2021, the total number of MBS performed in 2022 increased from approximately 262,893 to 280,000. The sleeve gastrectomy (SG) continues to be the most commonly performed procedure. The gastric bypass procedure trend remained relatively stable. The percentage of revision procedures and biliopancreatic diversion with duodenal switch procedures increased slightly. Intragastric balloon placement increased from the previous year. Endoscopic sleeve gastroplasty increased in numbers. CONCLUSIONS: There was a 6.5% increase in MBS volume from 2021 to 2022 and a 41% increase from 2020, which demonstrates a recovery from the COVID-19 pandemic. SG continues to be the most dominant MBS procedure.

Cardiometabolic Improvements After Metabolic Surgery and Related Presurgery Factors.

Context: Metabolic surgery remains the most effective and durable treatment for severe obesity and related metabolic diseases. Objective: We examined cardiometabolic improvements after metabolic surgery and associated presurgery demographic and clinical factors in a large multiracial cohort. Methods: Included were 7804 patients (20-79 years) undergoing first-time metabolic surgery at Vanderbilt University Medical Center from 1999 to 2022. Pre- and 1-year postsurgery cardiometabolic profiles were extracted from medical records, including body mass index (BMI), blood pressure, blood lipids, glucose, and hemoglobin A1c. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk was estimated per American College of Cardiology/American Heart Association equations. Pre- to postsurgery cardiometabolic profiles were compared by paired t-test, and associated factors were identified by multivariable linear and logistic regression. Results: Among 7804 patients, most were women and White, while 1618 were men and 1271 were Black; median age and BMI were 45 years [interquartile range (IQR): 37-53] and 46.4 kg/m2 (IQR: 42.1-52.4). At 1-year postsurgery, patients showed significant decreases in systolic blood pressure (10.5 [95% confidence interval: 10.1, 10.9] mmHg), total cholesterol (13.5 [10.3, 16.7] mg/dL), glucose (13.6 [12.9, 14.4] mg/dL), hemoglobin A1c (1.13% [1.06, 1.20]), and 10-year ASCVD risk (absolute reduction: 1.58% [1.22, 1.94]; relative reduction: 34.4% [29.4, 39.3]); all P < .0001. Older, male, or Black patients showed less reduction in 10-year ASCVD risk and lower odds of diabetes/hypertension/dyslipidemia remission than younger, female, or White patients. Patients with a history of diabetes, hypertension, dyslipidemia, or cardiovascular disease showed less cardiometabolic improvements than those without. Results were similar with or without further adjusting for weight loss and largely sustained at 2-year postsurgery. Conclusion: Metabolic surgery results in significant cardiometabolic improvements, particularly among younger, female, or White patients and those without comorbidities.

Sex- and operation-dependent effects on 5-year weight loss results of bariatric surgery.

BACKGROUND: Weight loss response after bariatric surgery is highly variable, and several demographic factors are associated with differential responses to surgery. Preclinical studies demonstrate numerous sex-specific responses to bariatric surgery, but whether these responses are also operation dependent is unknown. OBJECTIVE: To examine sex-specific weight loss outcomes up to 5 years after laparoscopic Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). SETTING: Single center, university, United States. METHODS: Retrospective, observational cohort study including RYGB (n = 5057) and vertical SG (n = 2041) patients from a single, academic health center. Percentage total weight loss (TWL) over time was examined with generalized linear mixed models to determine the main and interaction effects of surgery type on weight loss by sex. RESULTS: TWL demonstrated a strong sex-by-procedure interaction, with women having a significant advantage with RYGB compared with SG (adjusted difference at 5 yr: 8.0% [95% CI: 7.5-8.5]; P < .001). Men also experienced greater TWL over time with RYGB or SG, but the difference was less and clinically insignificant (adjusted difference at 5 yr: 2.9% [2.0-3.8]; P < .001; P interaction between sex and procedure type = .0001). Overall, women had greater TWL than men, and RYGB patients had greater TWL than SG patients (adjusted difference at 5 yr: 3.1% [2.4-3.2] and 6.9% [6.5-7.3], respectively; both P < .0001). Patients with diabetes lost less weight compared with those without (adjusted difference at 5 yr: 3.0% [2.7-3.2]; P < .0001). CONCLUSIONS: Weight loss after bariatric surgery is sex- and procedure-dependent. There is an association suggesting a clinically insignificant difference in weight loss between RYGB and SG among male patients at both the 2- and 5-year postsurgery time points.

Enhanced Patient Portal Engagement Associated with Improved Weight Loss Outcomes in Post-Bariatric Surgery Patients.

Background: Bariatric surgery is an effective intervention for obesity, but it requires comprehensive postoperative self-management to achieve optimal outcomes. While patient portals are generally seen as beneficial in engaging patients in health management, the link between their use and post-bariatric surgery weight loss remains unclear. Objective: This study investigated the association between patient portal engagement and postoperative body mass index (BMI) reduction among bariatric surgery patients. Methods: This retrospective longitudinal study included patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) at Vanderbilt University Medical Center (VUMC) between January 2018 and March 2021. Using generalized estimating equations, we estimated the association between active days of postoperative patient portal use and the reduction of BMI percentage (%BMI) at 3, 6, and 12 months post-surgery. Covariates included duration since surgery, the patient's age at the time of surgery, gender, race and ethnicity, type of bariatric surgery, severity of comorbid conditions, and socioeconomic disadvantage. Results: The study included 1,415 patients, mostly female (80.9%), with diverse racial and ethnic backgrounds. 805 (56.9%) patients underwent RYGB and 610 (43.1%) underwent SG. By one-year post-surgery, the mean (SD) %BMI reduction was 31.1% (8.3%), and the mean (SD) number of patient portal active days was 61.0 (41.2). A significantly positive association was observed between patient portal engagement and %BMI reduction, with variations revealed over time. Each 10-day increment of active portal use was associated with a 0.57% ([95% CI: 0.42- 0.72], P < .001) and 0.35% ([95% CI: 0.22- 0.49], P < .001) %BMI reduction at 3 and 6 months postoperatively. The association was not statistically significant at 12 months postoperatively (ß=-0.07, [95% CI: -0.24- 0.09], P = .54). Various portal functions, including messaging, visits, my record, medical tools, billing, resources, and others, were positively associated with %BMI reduction at 3- and 6-months follow-ups. Conclusions: Greater patient portal engagement, which may represent stronger adherence to postoperative instructions, better self-management of health, and enhanced communication with care teams, was associated with improved postoperative weight loss. Future investigations are needed to identify important portal features that contribute to the long-term success of weight loss management.

Comparative analysis of sleeve conversions of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program 2020 Database.

BACKGROUND: Although the sleeve gastrectomy (SG) is the dominant bariatric procedure, studies have shown conversion rates of up to 30%. These conversions are generally for weight regain (WR), insufficient weight loss (IWL) or gastroesophageal reflux disease (GERD). Before 2020, details on why conversions were being performed were not collected in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) Participant Use Data File (PUF). Now, the indication for sleeve conversion is noted in the PUF, allowing identification and reporting sleeve conversion reasons. OBJECTIVE: We aimed to examine the reasons for SG conversions nationwide. SETTING: The 2020 MBSAQIP PUF. METHODS: The 2020 MBSAQIP PUF was examined to determine the reasons why SG were converted to other operations. The data field of "Revision/Conversion Final Indication" was used along with "Procedure type." Primary bariatric operations were excluded. Descriptive statistics were applied. Different reasons for conversion and operations were compared by preoperative characteristics and operative outcomes. RESULTS: There were 103,782 primary SG reported in the 2020 PUF. There were 7181 SG that were converted to other operations. The most common conversion (86.2%) was to Roux-en-Y gastric bypass (RYGB). The main reason for SG conversion was GERD at 48.4%, followed by WR/IWL (41.9%). Biliopancreatic diversion with duodenal switch and single-anastomosis duodenoileal bypass with sleeve patients differed significantly from RYGB patients in specific preoperative characteristics and operative outcomes. CONCLUSION: The most common procedure SG is converted to is the RYGB. GERD was the most common reason for SG conversion, followed by WR/IWL.

Non-Operative Approach to Contained Perforated Marginal Ulcers: A Systematic Review and Case Series.

BACKGROUND: Perforated marginal ulcers (PMUs) are a rare but known complication of bariatric surgery. Management typically involves prompt surgical intervention, but limited data exists on non-operative approaches. This study reviews published data on non-operative management of PMUs and presents a case series of patients who were managed non-operatively. Our hypothesis is that certain patients with signs of perforation can be successfully managed non-operatively with close observation. METHODS: We completed a systematic review searching PubMed, Embase, Web of Science, Cochrane, and clinicaltrials.gov. Ultimately 3 studies described the presentation and non-operative management of 5 patients. Additionally, we prospectively collected data from our institution on all patients who presented between Dec. 2022 and Dec. 2023 with PMUs confirmed on imaging and managed non-operatively. RESULTS: In our literature review, three patients had Roux-en-Y gastric bypass (RYGB), while two had one anastomosis gastric bypass. One patient required surgery two days after admission. Another underwent elective conversion surgery weeks later for a non-healing ulcer. Two received endoscopic interventions. One patient recovered with nil-per-os (NPO) status, and intravenous proton pump inhibitor (PPI) treatment. The patients in our case series presented with normal vital signs, an average of 30 months after RYGB, and with CT scan signs of perforation. None of these patients required surgical or endoscopic intervention. CONCLUSION: In conclusion, while perforated marginal ulcers have traditionally been considered a surgical emergency, some patients can be successfully treated with non-operative management. More research is needed to identify the clinical presentation features, comorbidities, and imaging findings of this group.

Lessons learned from the metabolic and bariatric surgery accreditation and quality improvement program site surveys: common deficiencies and corrective actions.

BACKGROUND: The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) is a joint program between the American Society for Metabolic and Bariatric Surgery (ASMBS) and the American College of Surgeons (ACS). On-site surveys of the applicant programs to determine adherence to the MBSAQIP standards are a hallmark of the accreditation process. OBJECTIVES: A retrospective review of 619 site surveys completed over 2 years was performed to include analysis of reviewer decisions, tabulation and cross-reference of identified deficiencies to the MBSAQIP standards and determine final disposition of corrective actions and overall accreditation rates. SETTING: Accredited Hospitals (Community and Academic) within MBSAQIP. METHODS: This is a retrospective review of site surveys by expert panel. RESULTS: ≥1 MBSAQIP Standards deficiencies were present at 149 of the 619 program site surveys (24.07%). The 3 leading Standards in Deficiency were in order: Commitment to Quality Care, Continuous Quality Improvement Process, and Data Collection. Within a year following initial site survey of the149 programs with Standards deficiencies, 59 programs demonstrated compliance, 83 programs were placed on probation (with a specific time-frame to demonstrate compliance) and 7 programs were denied accreditation. Ultimately, 98.9% of programs were able to gain or maintain MBSAQIP accreditation. CONCLUSIONS: The MBSAQIP accreditation through on-site surveys can identify and improve program adherence to MBSAQIP standards.

Combination anti-obesity medications to effectively treat bariatric surgery weight regain at an academic obesity center.

Background: Combination anti-obesity medications (AOMs) to treat postoperative bariatric surgery weight regain have limited data on their use in the clinical setting. Understanding the optimal treatment protocol in this cohort will maximize weight loss outcomes. Methods: A retrospective review of bariatric surgery patients (N = 44) presenting with weight regain at a single academic multidisciplinary obesity center who were prescribed AOM(s) plus intensive lifestyle modification for 12 months. Results: Age: 28-76 years old, 93% female, mean weight 110.2 ± 20.3 kg, BMI 39.7 ± 7.4 kg/m2, presenting 5.2 ± 1.6 years post-bariatric surgery [27 (61.4%), 14 (31.8%), and 3 (6.8%) laparoscopic Roux-en-Y gastric bypass (RYGB), laparoscopic vertical sleeve gastrectomy (VSG), and open RYGB, respectively], with 15.1 ± 11.1 kg mean weight gain from nadir. Mean weight loss after medical intervention at 3-, 6-, and 12-month time points was 4.4 ± 4.6 kg, 7.3 ± 7.0 kg, and 10.7 ± 9.2 kg, respectively. At 12 months, individuals prescribed 3 or more AOMs lost more weight than those prescribed one (-14.5 ± 9.0 kg vs. -4.9 ± 5.7 kg, p < 0.05) irrespective of age, gender, number of comorbidities, initial weight or BMI, type of surgery, or GLP1 use. RYGB patients lost less weight overall (7.4% vs. 14.8% VSG respectively; p < 0.05). Conclusions: Combination AOMs may be needed to achieve optimal weight loss results to treat post-operative weight regain.

One- versus two-stage conversions of adjustable gastric bands: an analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database.

BACKGROUND: Laparoscopic adjustable gastric bands (AGB) are converted at high rates to secondary bariatric procedures. The available literature on the safety of converting in 1- versus 2-stage processes has not included large databases. OBJECTIVE: To evaluate the safety of a 1- versus 2-stage conversion of AGB. SETTING: Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP), United States. METHODS: The MBSAQIP database for the years 2020 and 2021 was evaluated. One-stage AGB conversions were identified using Current Procedural Terminology codes and database variables. Multivariable analysis was performed to determine whether 1- or 2-stage conversions were associated with 30-day serious complications. RESULTS: There were 12,085 patients who underwent conversion from previous AGB to sleeve gastrectomy (SG) (63.0%) or Roux-en-Y gastric bypass (RYGB) (37.0%), of whom 41.0% underwent conversion in 1 stage and 59.0% in 2 stages. Patients who underwent 2-stage conversions had higher body mass indexes. Rates of serious complications were higher for patients undergoing RYGB compared with SG (5.2% versus 3.3%, P < .001) but were similar between 1-stage and 2-stage conversions in both cohorts. In both cohorts, there were similar rates of anastomotic leaks, postoperative bleeding, reoperation, and readmissions. Mortality was rare and similar between conversion groups. CONCLUSIONS: There was no difference in outcomes or complications in 30 days between 1- and 2-stage conversions of AGB to RYGB or SG. Conversions to RYGB have higher complication and mortality rates than to SG, but there was no statistically significant difference between staged procedures. One- and 2-stage conversions from AGB are equivalent in safety.

An analysis of enhanced recovery pathways for bariatric surgery-preoperative fasting, carbohydrate loading, and aspiration risk: a position statement from the International Society for the Perioperative Care of Patients with Obesity.

Enhanced recovery pathways (ERPs) and recommendations have become widely accepted for metabolic and bariatric surgery, including recommendations for preoperative carbohydrate loading and duration of fasting status. There is still a lack of consensus regarding such protocols and the underlying issues of gastric emptying time, resting gastric volume and pH, and risk of aspiration in patients with severe obesity and in patients undergoing bariatric surgery. The goal of this position statement by the International Society for the Perioperative Care of Patients with Obesity (ISPCOP) is to provide an analysis of available data on preoperative fasting and loading with oral complex clear carbohydrate drinks as well its potential effects on perioperative risk of aspiration in the context of Enhanced Recovery Pathways for Metabolic and Bariatric Surgery (ERAMBS).

Benefits of Adjuvant Medical Weight Loss Intervention in Setting of Weight Regain and Inadequate Weight Loss After Weight Loss Surgery.

BACKGROUND: Currently, there is no nationally accepted protocol for addressing weight regain or inadequate weight loss after MBS. OBJECTIVES: To devise, implement, and evaluate a protocol targeting weight regain or inadequate weight loss in MBS patients at our institution. SETTING: Vanderbilt University Medical Center, Nashville, TN, United States. METHODS: Patients at least 6 months following primary sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) who achieved or were trending toward <50% excess body weight loss or who regained ≥10% of their lowest postoperative weight, were identified and referred for medical weight loss (MWL) intervention. Exclusion criteria were body mass index (BMI) ≤ 27 kg/m2, treatment with adjustable gastric banding, and conversion from SG to RYGB. RESULTS: 2274 patients who were >6 months out from surgery were evaluated over 12 months. 93 patients (86% female) met criteria for inclusion. 69 (74%) patients agreed to intervention and were followed for an average of 165 days (SD 106.89 days), demonstrating a mean weight change of -5.11 kg (SD 6.86 kg), and BMI change of -1.81 kg/m2 (SD 2.37 kg/m2). Patients who spent <90 days in a MWL program demonstrated less average weight loss (1.75 kg vs 6.48 kg) (P = .0042), and less change in BMI (-.63 kg/m2 vs -2.29 kg/m2) (P = .0037) when compared to patients who spent >90 days in the MWL intervention. CONCLUSIONS: This study identifies criteria for intervention in patients suffering weight regain or inadequate weight loss after MBS and demonstrates that standardized identification and referral for treatment results in modest weight loss.

American Society for Metabolic and Bariatric Surgery 2020 estimate of metabolic and bariatric procedures performed in the United States.

BACKGROUND: Metabolic and bariatric surgery (MBS), despite being the only effective durable treatment for obesity, remains underused as approximately 1% of all patients who qualify undergo surgery. The American Society for Metabolic and Bariatric Surgery created a Numbers Taskforce to specify annual rate of utilization for obesity treatment interventions and to determine if patients in need are receiving appropriate treatment. OBJECTIVE: The objective of this study was to provide the best estimated number of metabolic and bariatric procedures performed in the United States in 2020. SETTING: United States. METHODS: We reviewed data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP), National Surgical Quality Improvement Program, Bariatric Outcomes Longitudinal Database, and Nationwide Inpatient Sample. In addition, data from industry and state databases were used to estimate activity at nonaccredited centers. Data from 2020 were compared mainly with data from the previous 2 years. RESULTS: Compared with 2019, the total number of MBS performed in 2020 decreased from approximately 256,000 to 199,000. Sleeve gastrectomy continues to be the most common procedure. The gastric bypass procedure trend remained relatively stable, and the gastric band procedure trend continued to decline. The percentage of revision procedures and biliopancreatic diversion with duodenal switch procedures increased slightly. Single-anastomosis duodeno-ileostomy was listed for the first time in 2020. Intragastric balloons placement declined from the previous year. CONCLUSION: There was a 22.5% decrease in MBS volume from 2019 to 2020, which coincided with the COVID-19 pandemic. Sleeve gastrectomy continues to be the dominant procedure, and for the first time, single-anastomosis duodeno-ileostomy is reported in the MBSAQIP database.

Caloric Restriction and Weight Loss Are Primary Factors in the Early Tissue-Specific Metabolic Changes After Bariatric Surgery.

OBJECTIVE: To evaluate changes in insulin sensitivity, hormone secretion, and hepatic steatosis immediately after caloric restriction, vertical sleeve gastrectomy (VSG), and Roux-en-Y gastric bypass (RYGB). RESEARCH DESIGN AND METHODS: Obese subjects were assessed for 1) insulin sensitivity with hyperinsulinemic-euglycemic clamp with glucose tracer infusion, 2) adipokine concentrations with serum and subcutaneous adipose interstitial fluid sampling, and 3) hepatic fat content with MRI before and 7-10 days after VSG, RYGB, or supervised caloric restriction. RESULTS: Each group exhibited an ∼5% total body weight loss, accompanied by similar improvements in hepatic glucose production and hepatic, skeletal muscle, and adipose tissue insulin sensitivity. Leptin concentrations in plasma and adipose interstitial fluid were equally decreased, and reductions in hepatic fat were similar. CONCLUSIONS: The improvements in insulin sensitivity and adipokine secretion observed early after bariatric surgery are replicated by equivalent caloric restriction and weight loss.

Prevalence of thiamine deficiency is significant in patients undergoing primary bariatric surgery.

BACKGROUND: Patients undergoing metabolic and bariatric surgery are prone to developing micronutrient deficiencies, necessitating life-long nutritional supplementation and monitoring. Historically, these deficiencies were thought to be driven by postsurgical changes in absorption. Recent data, though, have demonstrated that obesity alone is also associated with micronutrient deficiencies. Thiamine deficiency, in particular, can lead to permanent neurologic deficits. OBJECTIVE: Identify thiamine deficiency prevalence within the preoperative metabolic and bariatric surgery patient population. SETTING: Single institution academic medical center. METHODS: A retrospective review of deidentified data was examined that included whole blood thiamine measured from consecutive patients from April 2018 to June 2019 (n = 346). Cohort characteristics were assessed including age, operation, preoperative weight, and race/ethnicity. The majority of the cohort were women (83%) with an average age of 44.9 years. Racial representation included White/Caucasian (73%) and Black (21%), while operations included Roux-en-Y gastric bypass (58%), sleeve gastrectomy (31%), and revisions (10%). RESULTS: Thiamine concentration was normally distributed with a mean of 144 nM. Overall, 3.5% of patients had thiamine concentrations below the lower limit of normal of <70 nM, while 35 additional patients (14%) were at risk for thiamine deficiency with concentrations <100 nM. On the average, these patients were of similar age and were all undergoing primary procedures (50% gastric bypass, 50% sleeve gastrectomy). Regression methods demonstrated that patients with thiamine deficiency tended to be females with higher body mass index, even after controlling for sex, height, and preoperative weight. After covariate adjustment, male sex and increasing height were both associated with higher thiamine concentration. CONCLUSION: Previously quoted rates of thiamine deficiency in the preoperative patient are variable, but we describe a significant number of patients with, or at risk of, thiamine deficiency. Male sex and increasing height are likely associated with increased skeletal muscle mass, which is enriched with thiamine. Routine thiamine measurement, either preoperatively or at the time of surgery, is warranted given its limited stores within the body and potential catastrophic complications associated with acute or chronic deficiency.

Modeling the Impact of Delaying Bariatric Surgery due to COVID-19: a Decision Analysis.

We developed a decision analysis model to evaluate risks and benefits of delaying scheduled bariatric surgery during the novel coronavirus disease (COVID-19) pandemic. Our base case was a 45-year-old female with diabetes and a body mass index of 45 kg/m2. We compared immediate with delayed surgery after 6 months to allow for COVID-19 prevalence to decrease. We found that immediate and delayed bariatric surgeries after 6 months resulted in similar 20-year overall survival. When the probability of COVID-19 infection exceeded 4%, then delayed surgery improved survival. If future COVID-19 infection rates were at least half those in the immediate scenario, then immediate surgery was favored and local infection rates had to exceed 9% before surgical delay improved survival. Surgeons should consider local disease prevalence and patient comorbidities associated with increased mortality before resuming bariatric surgery programs.

Change in Total Body Water as a Metric for Predicting Need for Outpatient Intravenous Fluids in Postoperative Bariatric Patients.

BACKGROUND: Dehydration drives a significant proportion of readmissions following bariatric surgery. Routinely performed body composition testing and total body water (TBW) calculations may present a novel method for diagnosing dehydration for outpatient intervention. We sought to determine if a change in TBW from preoperative baseline could help identify bariatric patients requiring outpatient intravenous fluid (IVF) administration for dehydration. METHODS: The VUMC Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database was retroactively queried for all patients undergoing bariatric surgery at an accredited bariatric surgery center from January 1, 2017 to May 31, 2018. Body composition test results presurgery and postsurgery were extracted from the electronic health record. Change in TBW was compared between patients requiring outpatient IVF and those who did not use multivariable logistic regression. RESULTS: 583 patients underwent surgery over the study period (388 laparoscopic Roux-en-Y gastric bypass, 195 sleeve). 62 (10.6%) required outpatient fluid administration for dehydration. After multivariable analysis, patients with an increased hospital length of stay at index operation were more likely to require outpatient IVF (odds ratio [OR] 1.65, 95% CI 1.22-2.2). Preexisting diabetes diagnosis was protective (OR 0.35, 95% CI 0.16-0.74). Neither 1-week nor 1-month change in TBW from preoperative baseline was significantly different between patients receiving outpatient IVF and those who did not. CONCLUSION: Increased hospital length of stay predicts patients at risk of postoperative dehydration requiring IVF administration. Body composition testing and TBW were not useful in distinguishing between populations. Further research is needed to examine the efficacy of outpatient IVF in preventing hospital readmissions for dehydration.

Fecal metagenomics and metabolomics reveal gut microbial changes after bariatric surgery.

BACKGROUND: Evidence from longitudinal patient studies regarding gut microbial changes after bariatric surgery is limited. OBJECTIVE: To examine intraindividual changes in fecal microbiome and metabolites among patients undergoing Roux-en-Y gastric bypass or vertical sleeve gastrectomy. SETTING: Observational study. METHODS: Twenty patients were enrolled and provided stool samples before and 1 week, 1 month, and/or 3 months after surgery. Shallow shotgun metagenomics and untargeted fecal metabolomics were performed. Zero-inflated generalized additive models and linear mixed models were applied to identify fecal microbiome and metabolites changes, with adjustment for potential confounders and correction for multiple testing. RESULTS: We enrolled 16 women and 4 men, including 16 white and 4 black participants (median age = 45 years; presurgery body mass index = 47.7 kg/m2). Ten patients had Roux-en-Y gastric bypass, 10 had vertical sleeve gastrectomy, and 14 patients provided postsurgery stool samples. Of 47 samples, median sequencing depth was 6.3 million reads and 1073 metabolites were identified. Microbiome alpha-diversity increased after surgery, especially at 3 months. Significant genus-level changes included increases in Odoribacter, Streptococcus, Anaerotruncus, Alistipes, Klebsiella, and Bifidobacterium, while decreases in Bacteroides, Coprocosccus, Dorea, and Faecalibacterium. Large increases in Streptococcus, Akkermansia, and Prevotella were observed at 3 months. Beta-diversity and fecal metabolites were also changed, including reduced caffeine metabolites, indoles, and butyrate. CONCLUSIONS: Despite small sample size and missing repeated samples in some participants, our pilot study showed significant postsurgery changes in fecal microbiome and metabolites among bariatric surgery patients. Future large-scale, longitudinal studies are warranted to investigate gut microbial changes and their associations with metabolic outcomes after bariatric surgery.

Preventing Nausea and Vomiting After Bariatric Surgery: Is the Apfel Risk Prediction Score Enough to Guide Prophylaxis?

Postoperative nausea and vomiting (PONV) is a frequent side effect in patients undergoing bariatric procedures. The simplified Apfel score is an attractive and frequently used tool to assess PONV risk in the general surgical population. Despite applying the recommendations based on the Apfel risk prediction score, several studies show that up to 82% of patients undergoing metabolic and bariatric surgery suffer from PONV in the PACU. A combination of multiple antiemetic drugs of different pharmacologic classes targeting a variety of receptors in addition to an intraoperative opioid-free TIVA technique should be considered in high-risk patients.