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.

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.

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.

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.

Reduced Risk of Cardiovascular Diseases after Bariatric Surgery Based on the New PREVENT Equations.

Background: We applied the novel Predicting Risk of Cardiovascular Disease EVENTs (PREVENT) equations to evaluate cardiovascular-kidney-metabolic (CKM) health and estimated CVD risk, including heart failure (HF), after bariatric surgery. Methods: Among 7804 patients (20-79 years) undergoing bariatric surgery at Vanderbilt University Medical Center during 1999-2022, CVD risk factors at pre-surgery, 1-year, and 2-year post-surgery were extracted from electronic health records. The 10- and 30-year risks of total CVD, atherosclerotic CVD (ASCVD), coronary heart disease (CHD), stroke, and HF were estimated for patients without a history of CVD or its subtypes at each time point, using the social deprivation index-enhanced PREVENT equations. Paired t-tests or McNemar tests were used to compare pre- with post-surgery CKM health and CVD risk. Two-sample t-tests were used to compare CVD risk reduction between patient subgroups defined by age, sex, race, operation type, weight loss, and history of diabetes, hypertension, and dyslipidemia. Results: CKM health was significantly improved after surgery with lower systolic blood pressure, non-high-density-lipoprotein cholesterol (non-HDL), and diabetes prevalence, but higher HDL and estimated glomerular filtration rate (eGFR). The 10-year total CVD risk decreased from 6.51% at pre-surgery to 4.81% and 5.08% at 1- and 2-year post-surgery (relative reduction: 25.9% and 16.8%), respectively. Significant risk reductions were seen for all CVD subtypes (i.e., ASCVD, CHD, stroke, and HF), with the largest reduction for HF (relative reduction: 55.7% and 44.8% at 1- and 2-year post-surgery, respectively). Younger age, White race, >30% weight loss, diabetes history, and no dyslipidemia history were associated with greater HF risk reductions. Similar results were found for the 30-year risk estimates. Conclusions: Bariatric surgery significantly improves CKM health and reduces estimated CVD risk, particularly HF, by 45-56% within 1-2 years post-surgery. HF risk reduction may vary by patient's demographics, weight loss, and disease history, which warrants further research.

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.

Safety culture and complications after bariatric surgery.

OBJECTIVE: To assess relationships between safety culture and complications within 30 days of bariatric surgery. BACKGROUND: Safety culture refers to the quality of teamwork, coordination, and communication, as well as responses to error in health care settings. Although safety culture is thought to be an important determinant of surgical outcomes, few studies have examined this empirically. METHODS: We surveyed staff from 22 Michigan hospitals participating in a statewide bariatric surgery collaborative. Each safety culture survey item was rated on a 1 to 5 Likert scale with lower scores representing better patient safety culture. These data were linked to clinical registry data for 24,117 bariatric surgery patients between 2007 and 2010. We used negative binomial regression to calculate incidence rates and incidence rate ratios measuring the increase in hospitals' rate of complications per unit increase in safety culture (individual items as well as hospital and operating room-specific subscales), controlling for patient risk factors, procedure mix, and bariatric procedure volume. RESULTS: All 22 hospitals participated in this study, submitting safety culture ratings from 53 surgeons, 102 nurses, and 29 operating room administrators. Rates of serious complications were significantly lower among hospitals receiving an overall safety rating of excellent from nurses (1.5%), compared with those receiving a very good (2.6%) or acceptable (4.6%) rating (P = <0.0001). Surgeons' overall safety ratings were also associated with rates of serious complications (2.1% excellent, 2.6% very good, 4.7% acceptable, P = 0.011). Nurses' ratings of the hospital-specific subscale (P = 0.002) and surgeons' ratings of the operating room-specific subscale (P = 0.045) were also associated with rates of serious complications. Of the individual items, those related to coordination and communication between hospital units were the most strongly associated with rates of complications. Operating room administrator ratings of safety culture were not related to rates of complications for any of the domains of safety culture studied. CONCLUSIONS: Safety culture is associated with rates of serious surgical complications in bariatric surgery. Although nurses provide better information about hospital safety culture, surgeons are better judges of safety culture in the operating room. Interventions targeting safety culture, particularly coordination and communication, seem to be important for quality improvement.

The comparative effectiveness of sleeve gastrectomy, gastric bypass, and adjustable gastric banding procedures for the treatment of morbid obesity.

OBJECTIVE: To evaluate the comparative effectiveness of sleeve gastrectomy (SG), laparoscopic gastric bypass (RYGB), and laparoscopic adjustable gastric banding (LAGB) procedures. BACKGROUND: Citing limitations of published studies, payers have been reluctant to provide routine coverage for SG for the treatment of morbid obesity. METHODS: Using data from an externally audited, statewide clinical registry, we matched 2949 SG patients with equal numbers of RYGB and LAGB patients on 23 baseline characteristics. Outcomes assessed included complications occurring within 30 days, and weight loss, quality of life, and comorbidity remission at 1, 2, and 3 years after bariatric surgery. RESULTS: Matching resulted in cohorts of SG, RYGB, and LAGB patients that were well balanced on baseline characteristics. Overall complication rates among patients undergoing SG (6.3%) were significantly lower than for RYGB (10.0%, P < 0.0001) but higher than for LAGB (2.4%, P < 0.0001). Serious complication rates were similar for SG (2.4%) and RYGB (2.5%, P = 0.736) but higher than for LAGB (1.0%, P < 0.0001). Excess body weight loss at 1 year was 13% lower for SG (60%) than for RYGB (69%, P < 0.0001), but was 77% higher for SG than for LAGB (34%, P < 0.0001). SG was similarly closer to RYGB than LAGB with regard to remission of obesity-related comorbidities. CONCLUSIONS: With better weight loss than LAGB and lower complication rates than RYGB, SG is a reasonable choice for the treatment of morbid obesity and should be covered by both public and private payers.

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.

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.

Predicting risk for venous thromboembolism with bariatric surgery: results from the Michigan Bariatric Surgery Collaborative.

OBJECTIVE: We sought to identify risk factors for venous thromboembolism (VTE) among patients undergoing bariatric surgery in Michigan. BACKGROUND: VTE remains a major source of morbidity and mortality after bariatric surgery. It is unclear which factors should be used to identify patients at high risk for VTE. METHODS: The Michigan Bariatric Surgery Collaborative maintains a prospective clinical registry of bariatric surgery patients. For this study, we identified all patients undergoing primary bariatric surgery between June 2006 and April 2011 and determined rates of VTE. Potential risk factors for VTE were analyzed using a hierarchical logistic regression model, accounting for clustering of patients within hospitals. Significant risk factors were used to develop a risk calculator for development of VTE after bariatric surgery. RESULTS: Among 27,818 patients who underwent bariatric surgery during the study period, 93 patients (0.33%) experienced a VTE complication, including 51 patents with pulmonary embolism. There were 8 associated deaths. Significant risk factors included previous history of VTE (OR 4.15, CI 2.42-7.08); male gender (OR 2.08, CI 1.36-3.19); operative time more than 3 hours (OR 1.86, CI 1.07-3.24); BMI category (per 10 units) (OR 1.37, CI 1.06-1.75); age category (per 10 years) (OR 1.25, CI 1.03-1.51); and procedure type (reference adjustable gastric band): duodenal switch (OR 9.45, CI 2.50-35.97); open gastric bypass (OR 6.48, CI 2.17-19.41); laparoscopic gastric bypass (OR 3.97, CI 1.77-8.91); and sleeve gastrectomy (OR 3.50, CI 1.30-9.34). Nearly 97% of patients had a predicted VTE risk less than 1%. CONCLUSIONS: In this population-based study, overall VTE rates were low among patients undergoing bariatric surgery. The use of an empirically based risk calculator will allow for the development of a risk-stratified approach to VTE prophylaxis.

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.

Predicting risk for serious complications with bariatric surgery: results from the Michigan Bariatric Surgery Collaborative.

OBJECTIVES: To develop a risk prediction model for serious complications after bariatric surgery. BACKGROUND: Despite evidence for improved safety with bariatric surgery, serious complications remain a concern for patients, providers and payers. There is little population-level data on which risk factors can be used to identify patients at high risk for major morbidity. METHODS: The Michigan Bariatric Surgery Collaborative is a statewide consortium of hospitals and surgeons, which maintains an externally-audited prospective clinical registry. We analyzed data from 25,469 patients undergoing bariatric surgery between June 2006 and December 2010. Significant risk factors on univariable analysis were entered into a multivariable logistic regression model to identify factors associated with serious complications (life threatening and/or associated with lasting disability) within 30 days of surgery. Bootstrap resampling was performed to obtain bias-corrected confidence intervals and c-statistic. RESULTS: Overall, 644 patients (2.5%) experienced a serious complication. Significant risk factors (P < 0.05) included: prior VTE (odds ratio [OR] 1.90, confidence interval [CI] 1.41-2.54); mobility limitations (OR 1.61, CI 1.23-2.13); coronary artery disease (OR 1.53, CI 1.17-2.02); age over 50 (OR 1.38, CI 1.18-1.61); pulmonary disease (OR 1.37, CI 1.15-1.64); male gender (OR 1.26, CI 1.06-1.50); smoking history (OR 1.20, CI 1.02-1.40); and procedure type (reference lap band): duodenal switch (OR 9.68, CI 6.05-15.49); laparoscopic gastric bypass (OR 3.58, CI 2.79-4.64); open gastric bypass (OR 3.51, CI 2.38-5.22); sleeve gastrectomy (OR 2.46, CI 1.73-3.50). The c-statistic was 0.68 (bias-corrected to 0.66) and the model was well-calibrated across deciles of predicted risk. CONCLUSIONS: We have developed and validated a population-based risk scoring system for serious complications after bariatric surgery. We expect that this scoring system will improve the process of informed consent, facilitate the selection of procedures for high-risk patients, and allow for better risk stratification across studies of bariatric surgery.

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.

Hospital complication rates with bariatric surgery in Michigan.

CONTEXT: Despite the growing popularity of bariatric surgery, there remain concerns about perioperative safety and variation in outcomes across hospitals. OBJECTIVE: To assess complication rates of different bariatric procedures and variability in rates of serious complications across hospitals and according to procedure volume and center of excellence (COE) status. DESIGN, SETTING, AND PATIENTS: Involving 25 hospitals and 62 surgeons statewide, the Michigan Bariatric Surgery Collaborative (MBSC) administers an externally audited, prospective clinical registry. We evaluated short-term morbidity in 15,275 Michigan patients undergoing 1 of 3 common bariatric procedures between 2006 and 2009. We used multilevel regression models to assess variation in risk-adjusted complication rates across hospitals and the effects of procedure volume and COE designation (by the American College of Surgeons or American Society for Metabolic and Bariatric Surgery) status. MAIN OUTCOME MEASURE: Complications occurring within 30 days of surgery. RESULTS: Overall, 7.3% of patients experienced perioperative complications, most of which were wound problems and other minor complications. Serious complications were most common after gastric bypass (3.6%; 95% confidence interval [CI], 3.2%-4.0%), followed by sleeve gastrectomy (2.2%; 95% CI, 1.2%-3.2%), and laparoscopic adjustable gastric band (0.9%; 95% CI, 0.6%-1.1%) procedures (P < .001). Mortality occurred in 0.04% (95% CI, 0.001%-0.13%) of laparoscopic adjustable gastric band, 0 sleeve gastrectomy, and 0.14% (95% CI, 0.08%-0.25%) of the gastric bypass patients. After adjustment for patient characteristics and procedure mix, rates of serious complications varied from 1.6% (95% CI, 1.3-2.0) to 3.5% (95% CI, 2.4-5.0) (risk difference, 1.9; 95% CI, 0.08-3.7) across hospitals. Average annual procedure volume was inversely associated with rates of serious complications at both the hospital level (< 150 cases, 4.1%; 95% CI, 3.0%-5.1%; 150-299 cases, 2.7%; 95% CI, 2.2-3.2; and > or = 300 cases, 2.3%; 95% CI, 2.0%-2.6%; P = .003) and surgeon level (< 100 cases, 3.8%; 95% CI, 3.2%-4.5%; 100-249 cases, 2.4%; 95% CI, 2.1%-2.8%; > or = 250 cases, 1.9%; 95% CI, 1.4%-2.3%; P = .001). Adjusted rates of serious complications were similar in COE and non-COE hospitals (COE, 2.7%; 95% CI, 2.5%-3.1%; non-COE, 2.0%; 95% CI, 1.5%-2.4%; P = .41). CONCLUSIONS: The frequency of serious complications among patients undergoing bariatric surgery in Michigan was relatively low. Rates of serious complications are inversely associated with hospital and surgeon procedure volume, but unrelated to COE accreditation by professional organizations.

Cardiovascular risk reduction following metabolic and bariatric surgery.

Cardiovascular disease (CVD) is the world's leading cause of mortality and obesity is a well-recognized risk factor of CVD. Early detection and management of CVD is critical to reduce CVD risk. Especially in patients suffering from obesity with obesity-related CVD risk factors such as hypertension (HTN), dyslipidemia, and diabetes mellitus (DM). A substantial and sustained decrease in body weight after metabolic and bariatric surgery is associated with a significant reduction of cardiovascular risk factors. This article reviews CVD risk models, mechanisms of CVD risk associated with obesity, and overall CVD risk reduction between different metabolic and bariatric procedures.

Efficacy and Safety of Recurrent Paraesophageal Hernia Repair with Roux-en-Y Gastric Bypass.

Roux-en-Y gastric bypass (RYGB) has been explored as a revisional option to failed paraesophageal hernia (PEH) repair with fundoplication, particularly in patients suffering from obesity. However, few studies have assessed long-term outcomes of RYGB with revisional PEH repair in regard to acid-suppressing medication use. We retrospectively identified 19 patients who underwent revisional PEH repair with RYGB between 2011 and 2018. The median operative time was 232 minutes with a median hospital length of stay of two days. The median length of follow-up was 24 months. Two patients (10.5%) had complications in the first 30 days, and five patients (26.3%) had complications within one year. Of the 12 patients on preoperative acid suppression, 6 (50%) were either off medication or on reduced dose at 12 months. The median BMI decrease was 14.4 kg/m² at 12 months and did not change significantly afterward. Although rates of acid-suppression medication use did not change overall after revisional PEH repair with RYGB, patients experienced successful long-term management of morbid obesity and sustained weight loss. Revisional PEH repair with RYGB is a safe and effective option, with a complication rate comparable with the reported rates after revisional foregut procedures such as revisional Nissen fundoplication.

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.