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Background: The incidence of obesity in African Americans (AAs) is higher than in non-AA in the USA. Previous studies using large national databases report that AA patients have worse outcomes than non-AA patients., Objectives: To assess perioperative outcomes among AA patients after MBS at a center of excellence (COE) that serves a large, diverse patient population., Setting: University Hospital METHODS: A retrospective analysis was performed on patients undergoing MBS between 2010 and 2020 at our two accredited MBSAQIP (Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program) COEs where the AA population makes up over 35% of the population. Preoperative variables were compared using unpaired t-test or chi-squared test where appropriate. Thirty-day outcomes were compared following propensity score matching (exact algorithm) of demographics and comorbidities., Results: Overall, 5742 patients (AA = 2058, 36%) had Roux-en-Y gastric bypass (AA = 1028, 26%) or sleeve gastrectomy (AA = 1030, 27%). AA patients were more often female (90.2% vs. 80.2%, p < 0.001) and had higher rates of hypertension (56.3% vs. 47.8%, p < 0.001), while non-AA patients had higher rates of hyperlipidemia (27.3% vs. 20.7%, p < 0.001) and obstructive sleep apnea (41.2% vs. 37.1%, p = 0.0024). Matched data showed that AA patients had higher rates of pulmonary embolism (PE) (0.3% vs. 0.1%, p = 0.020) and more emergency department visits (7.0% vs. 5.1%, p = 0.012) but no differences in mortality, readmission, reintervention, or reoperation rates., Conclusions: In a diverse area, AA patients who underwent MBS had similar perioperative outcomes compared to non-AA patients except that they experienced higher rates of PE. They also experienced higher rates of emergency department visits but had similar readmission rates., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Obesity rates in Hispanics and African Americans (AAs) are higher than in Caucasians in the USA, yet the rate of metabolic and bariatric surgery (MBS) for weight loss remains lower for both Hispanics and AAs., Methods: Patient demographics and outcomes of adult AA and Hispanic patients undergoing sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) procedures were analyzed using the MBSAQIP dataset [2015-2018] using unmatched and propensity-matched data., Results: In total, 173,157 patients were included, of whom 98,185 were AA [56.7%] [21,163-RYGB; 77,022-SG] and 74,972 were Hispanic [43.3%] [20,282-RYGB; 54,690-SG]). Preoperatively, the AA cohort was older, had more females, and higher BMIs with higher rates of all tracked obesity-related medical conditions except for diabetes, venous stasis, and prior foregut surgery. Intra- and postoperatively, AAs were more likely to experience major complications including unplanned ICU admission, 30-day readmission/reintervention, and mortality. After propensity matching, the differences in ED visits, treatment for dehydration, 30-day readmission, 30-day intervention, and pulmonary embolism remained for both SG and RYGB cohorts. Progressive renal insufficiency and ventilator use lost statistical significance in both cohorts. Conversely, 30-day reoperation, postoperative ventilator requirement, unplanned intubation, unplanned ICU admission, and mortality lost significance in the RYGB cohort, but not SG patients., Conclusion: Outcomes for AA patients were worse than for Hispanic patients, even after propensity matching. After matching, differences in major complications and mortality lost significance for RYGB, but not SG. These data suggest that outcomes for RYGB may be driven by the presence and severity of pre-existing patient-related factors., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: For patients with super obesity (BMI > 50 kg/m 2 ), biliopancreatic diversion/duodenal switch (BPD/DS) can be an effective bariatric operation. Technical challenges and patient safety concerns, however, have limited its use as a primary procedure. This study sought to assess the safety of primary versus revisional BPD/DS., Materials and Methods: The MBSAQIP database was queried for primary and revisional BPD/DS (2015-2018). Inclusion criteria were patients ≥ 18 years of age, BMI > 50 kg/m 2 , and with no concurrent procedures. Preoperative variables were compared using a chi-square test or Wilcoxon two-sample tests. Multivariate logistic or robust linear regression models were used to compare outcomes., Results: There were 3,378 primary BPD/DS and 487 revisional BPD/DS patients. Primary BPD/DS patients had higher BMI (56.5 [IQR4.4] versus 54.8 [IQR4] kg/m 2 , p < 0.0001) and had more diabetes mellitus type II (29.1% versus 17.2%, p < 0.0001). Intraoperatively, revisional BPD/DS had longer operative time (165 [IQR47] min versus 139 [IQR100] min, p < 0.0001). After adjusting for preoperative characteristics, there was no difference in 30-day readmission or ED visits (primary 12.9% versus revisional 14.6%), reoperation or reintervention (primary 5.7% versus revisional 7.8%), or mortality (primary 0.4% versus revisional 0.6%). In contrast, the revisional BPD/DS patients had higher odds of major morbidity (primary 3.4% versus revisional 5.3%, OR 1.9, CI 1.1-3.2, p = 0.019)., Conclusions: Revisional BPD/DS is associated with higher morbidity than primary BPD/DS in patients with super obesity. These patients should thus be counselled appropriately when choosing a primary or revisional bariatric procedure., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Roux-en-Y gastric bypass (RYGB) is an established surgical treatment for obesity. Variations in limb length during RYGB procedures have been investigated for optimizing weight loss while minimizing nutritional deficiencies. The role of the total alimentary limb length (TALL; Roux limb plus common channel [CC]), however, is poorly defined., Objective: Compare TALL in RYGB procedures for weight loss outcomes and malnutrition., Setting: Systematic review., Methods: Ovid Medline and PubMed databases were searched for entries between 1993 and 2020. Search terms included "gastric bypass" and "TALL." Two independent reviewers screened the results., Results: A total of 21 studies measured TALL in RYGB. Of these, 4 of 6 reported a relationship between TALL and weight loss. Additionally, 11 studies reported that when TALL was ≤400 cm and CC <200 cm, 3.4% to 63.6% of patients required limb lengthening for protein malnutrition., Conclusions: The majority of studies on RYGB do not report TALL length. There is some evidence that weight loss is affected by shortening TALL, while a TALL ≤400 cm with CC<200 should be avoided due to severe protein malnutrition. More studies on the effect of TALL are needed., (Copyright © 2021 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Purpose: Marginal ulceration (MU) is a common long-term complication following Roux-en-Y gastric bypass (RYGB). The causes of MU after RYGB are multifactorial and include surgical technique of constructing the gastrojejunal anastomosis (GJA). The purpose of this study is to evaluate the relationship between gastric pouch size in RYGB and MU using CT volumetrics., Material and Methods: Patients were retrospectively identified who underwent esophagogastroduodenoscopy (EGD) following RYGB at a tertiary care teaching hospital. Measurement of gastric pouch size was performed using 3-D CT software. Standard statistical methods were used, a univariate comparison was performed between MU and non-MU patients followed by a propensity-matched comparison to control for factors known to affect MU, and a propensity-matched subgroup analysis was also performed., Results: In total, 122 patients met criteria, 57 of which had MU on EGD and 65 who did not. The MU group had more smokers and patients with PPI use than the non-MU group, and the mean time from operation to CT scan was 26.6 months (range: 0-108 months). The MU group had a larger gastric pouch size than the non-MU group (34.1 ± 11.8 versus 20.1 ± 6.8 cm 3 ). When analyzed for matched patient cohorts, this difference remained for the MU group that included smokers and PPI use. When stratified for pouch size, for each 5 cm 3 increase in pouch size, patients had 2.4 times odds increase of MU formation., Conclusions: CT volumetric analysis demonstrated that a larger gastric pouch size was associated with MU following RYGB., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: Patients undergoing laparoscopic Roux-en-Y gastric bypass (RYGB) are at risk of developing strictures of the gastrojejunal anastomosis (GJA). Several variables can affect this, one of which may be the method of anastomosis. Between 2010 and 2014, our institution utilized three different anastomotic techniques for creating the GJA (25 mm end-to-end circular-stapled (CS), linear-stapled (LS), and robotic hand sewn (HS)). Our objectives were to compare the method of GJA relative to the subsequent development of anastomotic stricture., Methods: We queried our electronic health record for all patients who underwent an upper endoscopy (EGD) after RYGB (2010-2014). Patient charts were retrospectively reviewed for type of GJA, weight loss, complications, interventions, and revisions of the GJA., Results: In total, 1112 RYGB were performed at our institute, and 17.4% of patients (194/1112) had an upper endoscopy (EGD). Overall, 3.1% (34/1112) were found to have a stricture of the GJA. Patients undergoing a CS, LS, and HS anastomosis had GJA stricture rates of 4.9%, 0.5%, and 1.2% respectively (CS to LS (p < 0.05), p = NS among CS vs. HS, and LS vs. HS). The rate of GJA revision was 1.5%, 0.5%, and 0.1% (p = NS). In patients who had an EGD, excess BMI loss was 57.4%, 64.6%, and 59.2% (p = NS). In patients symptomatic from strictures, excess BMI loss was 69.4%, 83%, and 63.5% respectively (p = NS)., Conclusion: The anastomotic technique for creating of the GJA may impact the formation of strictures. Based on our experience, gastrojejunostomies created with a 2-mm EEA-stapling technique are at higher risk of strictures., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Jejunojejunal intussusception (JI) is a serious but rare complication that may occur following Roux-en-Y gastric bypass (RYGB) surgery. Causes of JI and best management strategy are not clearly defined., Methods: Electronic health records were queried for ICD 9/10 codes for intussusception after RYGB surgery (2009-2019), and charts retrospectively reviewed. Patient demographics, operative technique, presentation, radiology, and JI management were analyzed., Results: Of the 2,327 RYGB patients identified at our institute, 34 (1.5%) were treated for JI. The mean age was 45.0 ± 8.6 years, mean BMI (RYGB surgery) was 43.1 ± 8.2 kg/m 2 , mean BMI at JI was 28.3 ± 5.8 kg/m 2 , and 30/34 were female, The mean time between RYGB and JI was 5.5 ± 4.3 years (range 1-17 years). Of the JI patients identified, 9 had operative notes that did not include jejunojejunostomy linear stapler length (JJ-LSL). Of the remaining 25 JI patients, 9 had a 60-mm JJ-LSL and 16 had a 120-mm JJ-LSL. Rate of intussusception was higher in the 120-mm versus 60-mm JJ-LSL group (p < 0.05). Acute abdominal pain was present in all JI patients and 32/34 had radiologic findings (CT scan) that corroborated for JI. The majority of JI patients were managed operatively (26/34) with 22/26 using laparoscopy (2/22 were converted to open). Intraoperative findings included intussusception (15/26), and 9/26 had other pathologies (internal hernia (2/26), cholecystitis (4/26), marginal ulcer (3/26)). Operative management of JI was either reduction and enteropexy (7/15), reduction only (5/15), or JJ revision (3/15). Recurrence of JI occurred in 7/23 patients, of who 4/7 were managed operatively., Conclusions: In our experience, JI appears to be a relatively rare complication after RYGB surgery. However, for patients developing JI, the majority had a JJ length ≥ 120 mm, and most patients required operative management which was associated with a higher rate of conversion to open and risk of JI recurrence. Reduction only technique had the highest risk of JI recurrence and therefore is not recommended.

Background: Marginal ulceration (MU) and bleeding are possible complications following laparoscopic Roux-en-Y gastric bypass (RYGB). Our institution utilizes three techniques for performing the gastrojejunal anastomosis (GJA), providing a means to compare postoperative MU and bleeding as it relates to GJA technique., Objectives: We sought to analyze the incidence of MU and bleeding between the 25-mm end-to-end anastomosis (EEA) stapler, linear stapler (LS), and robotic hand-sewn (RHS) GJA techniques., Methods: Electronic health records for all patients who had an upper endoscopy (EGD) after RYGB were queried (2010-2014). Charts were retrospectively reviewed for type of GJA, complications, endoscopic interventions, and smoking and NSAID use., Results: Out of 1112 RYGBs, the GJA was created using an EEA, LS, or RHS approach in 58.6%, 33.6%, and 7.7% of patients, respectively. 17.4% had an EGD (19.9% EEA, 13.9% LS, and 14.0% RHS). Incidence of MU was 7.3% (9.3% EEA, 4.8% LS, and 5.8% RHS). Rates of EGD and MU were significantly higher after EEA vs. LS GJA (p<0.05). The bleeding rate was 1.5%, [1.1% EEA, 2.1% LS, and 2.3% RHS (p=NS)]. MU within 90 days of RYGB occurred in 4.1%, 0.8%, and 4.7%, respectively (p<0.05 for EEA vs LS only). NSAID and cigarette use were identified in 29.3%, 38.9%, and 60% and 17.2%, 22.2%, and 20%, respectively, for the EEA, LS, and RHS GJA (p=NS)., Conclusion: The method of GJA has an impact on rate of MU formation. A GJA fashioned with a 25-mm EEA stapler tends to have higher rates of EGD and MU.

Background: Correlating patient outcomes with length of stay (LoS) is an important consideration in metabolic and bariatric surgery. At present, conflicting data exists regarding patient safety for ambulatory (AMB) metabolic and bariatric surgery., Objective: Outcomes for AMB-metabolic and bariatric surgery patients (LoS <1 d) undergoing laparoscopic Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) were compared with matched patients with LoS ≥1 day (non-AMB) using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) registry., Setting: MBSAQIP national database., Methods: The MBSAQIP registry was queried for patients undergoing SG or RYGB (2015-2017) and patients grouped as AMB/non-AMB. Exclusion criteria included LoS >4 days, age <18 or >75 years, revision surgery, gastric banding, body mass index <35 kg/m 2 , and day of surgery mortality. Variables were combined into major/minor complications and 30-day mortality. Analysis was performed using univariate and multivariate logistic regression and propensity matching., Results: After exclusions were applied 408,895 patients remained (9973 AMB). Overall, 111,279 patients underwent RYGB (1032 AMB) and 297,616 underwent SG (8941 AMB), with similar demographic characteristics and co-morbidities between groups. For AMB patients, there was no increase in 30-day mortality, reoperation, or readmission, and fewer drains were placed versus matched non-AMB patients. In AMB-SG patients more surgical site infections were reported versus non-AMB-SG, although AMB-SG patients had fewer intensive care unit admissions. For AMB-RYGB, no differences in complications were detected versus non-AMB-RYGB., Conclusion: Based on our analysis of the MBSAQIP database, patients undergoing laparoscopic RYGB or SG procedures can be safely discharged on the day of their procedure without increased incidence of mortality, reoperation, or readmission., (Published by Elsevier Inc.)

Background: The incidence of obesity is disproportionally high in African Americans (AA) in the United States. This study compared outcomes for AA patients undergoing Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) with non-AA patients., Methods: The MBSAQIP database was reviewed for RYGB and SG patients (2015-2017). Patients were identified as AA or non-AA and grouped to RYGB or SG. Combined and univariate analyses were performed on unmatched/propensity matched populations to assess outcomes., Results: After applying exclusion criteria, 75,409 AA and 354,305 non-AA patients remained. Univariate analysis identified AA-RYGB and AA-SG patients were heavier and younger than non-AA patients. Overall, AA patients tended to have fewer preoperative comorbidities than non-AA patients with the majority of AA comorbidities related to hypertension and renal disease. Analysis of propensity matched data confirmed AA bariatric surgery patients had increased cardiovascular-related disease incidence compared with non-AA patients. Perioperatively, AA-RYGB patients had longer operative times, increased rates of major complications/ICU admission, and increased incidence of 30-day readmission, re-intervention, and reoperation, concomitant with lower rates of minor complications/superficial surgical site infection (SSI) compared with non-AA patients. For SG, AA patients had longer operative times and higher rates of major complications and 30-day readmission, re-intervention, and mortality, coupled with fewer minor complications, superficial/organ space SSI, and leak., Conclusion: African American patients undergoing bariatric surgery are younger and heavier than non-AA patients and present with different comorbidity profiles. Overall, AAs exhibit worse outcomes following RYGB or SG than non-AA patients, including increased mortality rates in AA-SG patients.

Background: The obesity rate for the Hispanic population is significantly higher than that of white, non-Hispanic people in the United States, yet Hispanic people undergo disproportionately fewer metabolic and bariatric surgery procedures. This study used the Metabolic Bariatric Surgery Accreditation and Quality Improvement Program data registry to examine potential differences in preoperative co-morbidities and postoperative outcomes in Hispanic adults undergoing sleeve gastrectomy or Roux-en-Y gastric bypass procedures in the United States., Objectives: To study the presence of the Hispanic paradox in metabolic and bariatric surgery utilizing the MBSAQIP registry., Setting: Academic Teaching Institution., Methods: Participant User Files from the Metabolic Bariatric Surgery Accreditation and Quality Improvement Program were reviewed for patients undergoing sleeve gastrectomy or Roux-en-Y gastric bypass (2015-2017). Patients were grouped by race (Hispanic versus all other races) and primary procedure performed. Variables for major and minor postoperative complications were combined. A univariate analysis was performed on unmatched and propensity-matched cohorts., Results: After applying exclusions, 53,353 (13.7%) Hispanic patients and 335,299 non-Hispanic patients remained. A univariate analysis demonstrated Hispanic patients had the lowest preoperative co-morbidity profile compared with all other races and decreased rates of major and minor postoperative complications. Using matched-cohort data, when complications were assessed and grouped as major/minor complications, rates of major and minor complications in Hispanic patients were lower in the Roux-en-Y gastric bypass group, despite Hispanic patients having higher leak rates. Similarly, there were no differences between Hispanic/non-Hispanic sleeve gastrectomy patients in overall major/minor complication rates despite Hispanic patients exhibiting higher venous thromboembolism and lower bleeding compared with non-Hispanic patients., Conclusion: Hispanic patients undergo disproportionately low rates of metabolic and bariatric surgery procedures and present with lower incidence of preoperative co-morbidities. Additionally, Hispanic patients have the same or decreased incidence of postoperative complications compared with non-Hispanic patients, thereby corroborating the Hispanic paradox., (Copyright © 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Obesity in the United States is increasingly prevalent in adolescents. Metabolic and bariatric surgery is offered at select sites to adolescents (<18 yr). Controversy exists regarding the safety of performing metabolic and bariatric surgery in adolescents., Objectives: The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program registry was employed to compare outcomes of adolescents with adults (18-40 yr) undergoing sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB)., Setting: Academic Teaching Institution., Methods: The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program Participant User Files were reviewed for patients undergoing SG or RYGB (2015-2018). Patients were stratified by age and outcomes for adolescents versus adults compared. A bivariate analysis was performed on propensity-matched data., Results: After exclusion criteria were applied, 227,671 patients <40 years remained, of whom 1005 were adolescents. For those undergoing RYGB (13.8% adolescents, 25.3% adults), demographic characteristics were similar. Adolescent SG patients were more likely to be male and Hispanic, but less likely to be smokers or have preoperative co-morbidities. There were no differences in infection rates, mortality, major complications, reoperation, readmission, or other interventions for RYGB and SG groups. For both adult SG and adolescent SG, patients' operative times were less than adult and adolescent RYGB, respectively. However, operative times were shorter for adolescent RYGB versus adult RYGB patients, yet longer for adolescent SG patients versus adult SG patients., Conclusions: Metabolic and bariatric surgery is as safe for adolescents undergoing an SG or RYGB as adults. Currently, SG is more commonly performed in adolescents than RYGB, and adolescent SG patients have similar outcomes and shorter operating room times compared with adolescent RYGB patients., (Copyright © 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Bariatric surgery is the most effective modality to treat obesity and obesity-related comorbidities. This study sought to utilize the MBASQIP® Data Registry to analyze the impact of age at time of surgery on outcomes following sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) procedures., Methods: The MBSAQIP® Data Registry for patients undergoing SG or RYGB procedures between 2015 and 2016 was reviewed. Patients were divided into 4 age groups [18-44; 45-54; 55-64; > 65 years]. Minimal exclusions for revisional and/or emergency surgery were selected and combination variables created to classify complications as major or minor. A comorbidity index was constructed to include diabetes, gastroesophageal reflux disease (GERD), obstructive sleep apnea (OSA), and prior cardiac surgery. Univariate and multivariate logistic regression analyses were performed to compare age stratifications to the young adult (18-45 years) cohort., Results: Of 301,605 cases, 279,419 cases (71.2% SG) remained after applying exclusion criteria (79.2% female, mean BMI 45.5 ± 8.1 kg/m 2 , 8.9% insulin-dependent diabetics). Mean age was 44.7 ± 12.0 years (51.3% 18-44 years; 26.9% 45-54 years; 16.3% 55-64 years; 5.5% > 65 years). A univariate analysis demonstrated preoperative differences of lower BMI with increasing age concomitant with increasing frequency of RYGB and a higher comorbidity index (p < 0.0001 vs. 18-45 years). At age > 45 years, major complications and 30-day mortality increased independent of procedure type (p < 0.0001). A multivariate analysis controlling for comorbidity indices demonstrated increasing age (> 45 years) increased risk for major complications and mortality., Conclusion: Overall, bariatric surgery (SG or RYGB) remains a low mortality risk procedure for all age groups. However, all age group classifications > 45 years had higher incidence of major complications and mortality compared to patients 18-45 years (despite older individuals having lower preoperative BMI) indicating delaying surgery is detrimental.

Background: Previous reports of bariatric surgery outcomes when cases are assisted by residents and/or fellows have been inconclusive., Objective: To compare bariatric surgery outcomes for cases with surgical trainees (ST; residents and fellows) versus nonsurgical trainees (nST; all other assistants) using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) Registry., Setting: Academic teaching., Methods: The MBSAQIP Registry was reviewed (2015-2017) for Roux-en-Y gastric bypass, sleeve gastrectomy, and revision surgery based on ST and nST status. Univariate, multivariate logistic regression, and propensity matching analyses were performed., Results: Of 477,670 cases, 26.8% were performed with ST. For ST patients 79.9% were female (versus 80.3% nST) and mean body mass index was 45.2 ± 8 kg/m 2 (versus 45.0 ± 8.1 kg/m 2 nST). Overall, 31.7% of patients underwent Roux-en-Y gastric bypass (versus 25.7% nST), 65.9% underwent sleeve gastrectomy (versus 71.6% nST), and 2.4% of patients had revision surgery (versus 2.7% nST). After matching, no difference in 30-day mortality was observed between groups. However, ST patients had higher incidence of deep vein thrombosis (P = .004), pulmonary embolism (P = .005), superficial surgical site infection (P < .0001), postoperative sepsis (P = .005), blood transfusions (P = .0307), nonoperative interventions (P = .004), 30-day readmission rates (P < .0001), and longer operative times (P < .0001), but lower 30-day reoperation rates (P = .0001)., Conclusion: Overall, there was no difference observed in 30-day mortality between the ST and nST groups. However, despite lower 30-day reoperation rates, ST patients exhibited higher rates of postoperative deep vein thrombosis, pulmonary embolism, superficial surgical site infection, postoperative sepsis, blood transfusions, 30-day readmission rates, and longer operative times than nST patients., (Copyright © 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Nonalcoholic fatty liver disease (NAFLD) represents the most common cause of chronic liver disease in the USA. Biopsy has been the standard for determining fibrosis but is invasive, costly, and associated with risk. Previous studies report a calculated "NAFLD fibrosis scores" (cNFS) as a means to overcome the need for biopsy. We compared cNFS versus biopsy-pathological scoring for patients undergoing bariatric surgery., Methods: We retrospectively reviewed patients with available preoperative labs and patient information undergoing Roux-en-Y gastric bypass (RYGBP) surgery at a single institution over a 5.5-year period. Biopsy samples were blind scored by a single hepatopathologist and compared with scores calculated using a previously reported cNFS., Results: Of the 225 patients that met the inclusion criteria, the mean body mass index was 44.6 ± 5.4 kg/m(2) and 85 % were female. Using the cNFS, 39.6 % of patients were categorized into low fibrosis, 52 % indeterminate, and 8.4 % high fibrosis groups. Analysis of fibrosis by pathology scoring demonstrated 2 of 89 (2.2 %) and 7 of 110 (3.4 %) had significant fibrosis in the low and intermediate groups, respectively. Conversely, in the high fibrosis group calculated by cNFS, only 6 of 19 (31.6 %) exhibited significant fibrosis by pathology scoring., Conclusions: No definitive model for accurately predicting presence of NAFLD and fibrosis currently exits. Furthermore, under no circumstances should a clinical "NAFLD fibrosis score" replace liver biopsy at this time for RYGBP patients.