Biliopancreatic Limb Length Research Articles

Using artificial intelligence to evaluate adherence to best practices in one anastomosis gastric bypass: first steps in a real-world setting.

Safety in one anastomosis gastric bypass (OAGB) is judged by outcomes, but it seems reasonable to utilize best practices for safety, whose performance can be evaluated and therefore improved. We aimed to test an artificial intelligence-based model in real world for the evaluation of adherence to best practices in OAGB.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary. A retrospective single-center study of 89 consecutive OAGB videos was captured and analyzed by an artificial intelligence platform (10/2020-12/2023). The platform currently provides assessment of four elements, including bougie insertion, full division of pouch, view of Treitz ligament, and leak test performed. Two bariatric surgeons viewed all videos, categorizing these elements into Yes/No adherence. Intra-rater and inter-rater agreements were computed. The estimates found in greatest consensus were used to determine the model's performance. Clinical data retrieval was performed. Videos included primary (71.9%) and conversion (28.1%) OAGB. Patients' age was 41.5 ± 13.6y and body mass index 42.0 ± 5.7kg/m2. Anastomosis width was 40mm (IQR, 30-45), and biliopancreatic limb length was 200cm (IQR, 180-200). Operative duration was 69.1min (IQR 55.3-97.4), mainly spent on gastric transection (26%) and anastomosis (45%). Surgeons' intra-rater overall agreements ranged 93-100% (kappa 0.57-1). Inter-rater overall agreements increased to 99-100% (kappa 0.95-1) in the second review, set as reference point to the model. The model's overall accuracy ranged 82-98%, sensitivity 91-94%, and positive predictive value 88-99%. Specificity ranged 17-92% and negative predictive value 20-68%. The model appears to have high accuracy, sensitivity, and positive predictive value for evaluating adherence to best practices for safety in OAGB. Considering the paucity of negative estimates in our study, more low-performance cases are needed to reliably define the model's specificity and negative predictive value. Adding more best practices, tested in multi-center studies will enable cross-border standardization of the procedure.

Optimal Bilio-Pancreatic Limb (BPL) Length in One Anastomosis Gastric Bypass (OAGB) Surgery.

One Anastomosis Gastric Bypass (OAGB) is a modification of Mason's loop bypass procedure, which has become a well-established procedure in the field of Bariatric and Metabolic surgery (BMS). However, the optimal length of Biliopancreatic Limb (BPL) in OAGB remains an ongoing debate. This review aims to analyse the current trends and evidence regarding different BPL lengths in OAGB and their impact on outcomes. A comprehensive literature search using search terms, 'One Anastomosis Gastric Bypass', 'Mini-Gastric Bypass', 'Biliopancreatic Limb', and 'Small bowel limb' was conducted. The articles were extracted and critically appraised for various outcomes including weight loss, comorbidities resolution, nutritional deficiencies, complications and quality of life. There appears to be a direct relationship between length of the BPL and the incidence of malnutrition. Longer BPL lengths (> 200cm) are associated with a higher risk of malnutrition. Shorter BPL lengths (150-200cm), particularly 150cm, have shown promising outcomes. Shorter BPL lengths offer potential advantages by reducing nutritional risks associated with OAGB. Further research with long-term follow-up is needed to investigate the efficacy of even shorter BPL lengths (< 150cm).

60-month follow-up of Long Limb vs. Standard Limb Roux-en-Y gastric bypass for type 2 diabetes and obesity: the LONG LIMB RCT

Background Roux-en-Y gastric bypass is an established treatment option for type 2 diabetes and obesity. However, the optimal lengths for the small intestinal limbs remain controversial with variation in practice. A longer biliopancreatic limb length of 150 cm (‘Long Limb’) was hypothesised to better improve glycaemia compared to the standard Roux-en-Y gastric bypass with a biliopancreatic limb of 50 cm (‘Standard Limb’). The aim of the trial was to evaluate the short-term mechanistic outcomes and the long-term clinical outcomes and safety of Long Limb versus Standard Limb Roux-en-Y gastric bypass. Methods We undertook a prospective double-blinded randomised controlled parallel group clinical trial across two sites in London. Participants were randomly assigned (1 : 1) to Long Limb or Standard Limb Roux-en-Y gastric bypass with a fixed alimentary limb of 100 cm. Mixed-meal tolerance tests and a hyperinsulinaemic-euglycaemic clamp were used to measure postprandial gut hormone response, glucose tolerance and insulin sensitivity. The primary outcome for the mechanistic study was the secretion of active glucagon-like peptide-1 at 2 weeks after intervention. Secondary outcomes were insulin sensitivity and fasting/postprandial glucose and insulin concentrations. Clinical outcomes, including HbA1c, number of glucose-lowering medications, weight loss, blood pressure and low-density lipoprotein cholesterol, and adverse events, were collected up to 60 months postoperatively to assess the durability of postoperative weight and glycaemic improvements. Results Of the 53 participants randomised, 48 completed the 12-month mechanistic investigation (Standard Limb 24, Long Limb 24) and 38 completed the 60-month follow-up (Standard Limb 18, Long Limb 20). The 24- to 60-month extension study coincided with two waves of the COVID-19 pandemic. There was no difference between the Standard Limb and Long Limb groups for postprandial active glucagon-like peptide-1 secretion (70 ± 32 pmol/L vs. 70 ± 19 pmol/L, respectively; p = 0.43), hepatic insulin sensitivity (3.4 ± 0.9 µmol/kg/min vs. 3.4 ± 1.4 µmol/kg/min, respectively; p = 0.94) and peripheral insulin sensitivity (29.0 ± 9.1 µmol/kg/min vs. 29.2 ± 9.9 µmol/kg/min, respectively; p = 0.98) at 2 weeks post intervention. There was no difference between the Standard Limb and Long Limb groups at 60-month follow-up for glycaemic remission (33% vs. 45%, respectively; p = 0.52), percentage total weight loss (27 ± 9% vs. 26 ± 8%, respectively; p = 0.34), systolic blood pressure (127 ± 11 mmHg vs. 125 ± 14 mmHg, respectively; p = 0.63) and low-density lipoprotein cholesterol (2.0 ± 1.0 mmol/L vs. 2.4 ± 1.0 mmol/L, respectively; p = 0.27). Conclusion In conclusion, this study has demonstrated the substantial clinical benefit of Roux-en-Y gastric bypass to people living with type 2 diabetes and obesity; however, this trial did not demonstrate a clinical rationale for the elongation of the biliopancreatic limb of Roux-en-Y gastric bypass to 150 cm to enhance metabolic outcomes for type 2 diabetes and obesity. Limitations Although the surgical procedures were designed according to United Kingdom clinical practice at the time of study inception, there is substantial variation in practice internationally. Our original investigation was powered for mechanistic outcomes and is not powered to detect differences in clinical outcomes. Lastly, the loss of participants to follow-up may have limited our statistical power to detect significant differences in the clinical outcomes. We therefore cannot derive definitive conclusions on the relative clinical efficacy of the two variants of Roux-en-Y gastric bypass. Funding This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation (EME) programme as award number NIHR130639.

Long-Term Weight Loss Outcomes of One Anastomosis Gastric Bypass: Assessment of 1971 Patients with 5-9-Year Follow-Up.

While OAGB shows promise in the short to medium term, its long-term durability, weight trends, blood levels of metabolic factors and nutrients, and potential complications require further exploration through larger, longer-term studies. This study contributes to the growing body of evidence by reporting on the long-term outcomes of patients with severe obesity who underwent OAGB. A retrospective study on prospectively collected data was conducted on a sample of 1917 patients who underwent OAGB between 2010 and 2019 and had a BMI ≥ 35 kg/m2. The data required for the study were obtained from our national registry database of obesity surgery (INOSD). In total, 1971 patients were included, with 1474 (74.8%) female predominance. The mean age and BMI before surgery were 40.31 ± 11.21 years (range 18 to 75 years) and 46.68 ± 6.7 kg/m2 (range 35-86.57 kg/m2), respectively. The mean biliopancreatic limb length was 185.02 ± 15.61 cm. Our follow-up rate was 96.19% and 75.85% in 24 and 60 months after OAGB, respectively. %TWL and %EWL reached the maximum 18 months after the operation (36.49 ± 7.77, 81.54 ± 19.18, respectively). Suboptimal initial weight loss (SIWL) 2 years after surgery was 2.9%, and TWL less than 20% and EWL less than 50% were calculated at 5-year follow-up, which was 10.2% and 14.8%, respectively. The results of this study indicate thatOAGB has acceptable long-term effects on weight loss and the remission or improvement of obesity-relatedmedical conditions.

Revisional Surgery Due to Weight Regain or Insufficient Weight Loss Following One Anastomosis Gastric Bypass.

One anastomosis gastric bypass (OAGB) is a common procedure associated with satisfactory outcomes. Revisional surgery due to weight regain or insufficient weight loss (WR/IWL) after OAGB is underreported. A retrospective analysis of a single-bariatric surgeon database was conducted. All patients undergoing revisional surgery after OAGB due to WR/IWL were included. Ten patients were included in this case series. The median time between OAGB and revisional surgery was 44.9 months. The median body mass index (BMI) was 41.6 at pre-OAGB and 38.6 at pre-revision. The median age at OAGB revision was 40 years. The median biliopancreatic limb (BPL) length at revision was 160 cm. BPL elongation was performed in three patients, conversion to Roux-en-Y gastric bypass (RYGB) with BPL elongation in three patients, RYGB without BPL elongation in three patients, and one patient underwent conversion to single anastomosis duodeno-ileal bypass with sleeve (SADI-S). Pouch resizing was performed in four patients. One patient was reoperated due to a staple line leak from pouch resizing after conversion to RYGB. At a mean postoperative follow-up of 19 months, the median BMI and total weight loss were 30 and 18%, respectively. Higher weight loss outcomes occurred with BPL elongation (average: 24.8%) and SADI-S (average: 23.4%), while conversion to RYGB, with or without elongation, showed lower weight loss outcomes (11.5% and 7.8%, respectively). WR/IWL after OAGB can be encountered during follow-up. In this case series, several options of revisions were evaluated, and BPL elongation or conversion to SADI-S correlated with better weight loss outcomes.

MGB-OAGB International Club-Results of a Modified Delphi Consensus on Controversies in OAGB.

One anastomosis gastric bypass (OAGB) presently constitutes 7.6% of all metabolic and bariatric surgery (MBS) procedures globally. Despite being approved by the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) as a standalone MBS procedure and two consensus efforts in the past, multiple areas of controversies remain. This consensus builds upon previous consensus efforts to address unresolved controversies in the field. A modified Delphi consensus exercise was conducted over 4weeks under the aegis of the MGB-OAGB International Club. A panel of 86 bariatric experts from 25 countries participated in 3 rounds of voting on 29 questions on patient selection, technical standardization, revisional surgeries, and post-operative care. Consensus was defined as at least 70% agreement. Consensus was achieved on 22 out of 29 questions. Key areas of agreement included suitability of OAGB for adolescents above the age of 15years and patients with class 1 obesity with uncontrolled type 2 diabetes. Patients with severe esophagitis and Barrett's esophagus were not considered as good candidates for OAGB. Crural repair with OAGB was considered as an appropriate procedure in patients with large hiatus hernia. While a bilio-pancreatic limb (BPL) length of 150 - 200cm was deemed suitable, it was recommended to tailor the BPL length to prevent protein energy malnutrition. It was also agreed to routinely administer ursodeoxycholic acid and proton-pump inhibitors for 6months post-operatively. This modified Delphi consensus represents a critical step forward in addressing the controversies surrounding OAGB. It also emphasizes on the importance of individualized patient care and the need for ongoing research to refine surgical practices and improve outcomes.

BS SO11 - Impact of various biliopancreatic limb lengths on EBWL, Nutritional deficiencies and resolution of ORMs -MGB/OAGB

Abstract Background OAGB was first described by Robert Rutledge. There have been a few modifications of MGS since its first introduction. There have been modifications in the limb length, pouch side, type, and location of anastomosis. Concerns have been raised about nutritional deficiencies by various authors about the longer limb length. Few other authors have published promising results from their studies regarding good outcomes on longer limb length. Method We follow BMI based guidelines at our center to decide on OAGB limb length.BMI &amp;lt; 50- BP limb length – 150 cmBMI &amp;gt;50 BP limb length- 200 cmBMI &amp;gt; 60 BP limb length- 250 cm. We analysed our results from BP limb lengths &amp;gt;/=200 cm in terms of EBWL, ORM resolutions, Nutritional deficiencies and compared it to similar outcomes in BP limb lengths of 150 cm Results Our data is currently under review. Initial assessment suggests promising results of longer limb lengths with no major complications highlighted. All the longer limb length patients are under 3 monthly follow up with 2 years follow up data now being analysed. Literature review suggests inadequate weight loss with shorter limb lengths. The longer limb lengths are associated with nutritional deficiencies. We are excited to take this opportunity to discuss our results Conclusion Limb length should be tailored as per patient factors and available support. One standard limb length doesn't apply to all the patients.

A Longer Biliopancreatic Limb and Shorter Common Channel Enhance Weight Loss But May Have Harmful Effects in Mouse Models of Roux-en-Y Gastric Bypass.

RYGB consists of the Roux limb (RL), the biliopancreatic limb (BPL), and the common channel (CC). There is no consensus on the optimal limb lengths. Using a mouse model of RYGB, 30 diet-induced obese mice were divided into two groups with varying BPL and CC lengths: a standard BPL with a long CC (RYGB S) and a long BPL with a short CC (RYGB L). Additionally, 9 age-matched, lean control mice (LC) were also included in this study. RYGB S had limb lengths of RL = 17%, BPL = 24%, and CC = 59%. RYGB L had limb lengths of RL = 17%, BPL = 32%, and CC = 51%. RYGB S and RYGB L had 67% and 40% survival, respectively. Mortality in RYGB L included more instances where the cause of death was not apparent. RYGB L demonstrated greater weight loss, lower energy expenditure, and lower heart mass as compared to RYGB S. Both RYGB groups had lower epidydimal fat mass, spleen mass, and bone mineral density compared to LC. RYGB L had a lower heart mass than RYGB S and LC. While the relative abundance of Eubacterium was lower in RYGB L than in RYGB S, no other gut microbiota differences were observed. A longer BPL with a shorter CC induces greater weight loss but may lead to adverse effects, including lower heart mass, reduced bone density, and deaths with unclear causes.

A Meta-Analysis Comparing RYGB with Long Biliopancreatic Limb (BPL) Versus Long Alimentary Limb (AL) in Groups with Equal or Nearly Equal Combined Bypass Lengths (Combined BPL and AL Lengths): Does Switching Seats Enhance Weight Loss?

It is well-established that extending either the biliopancreatic limb (BPL), the alimentary limb (AL), or both, results in increased combined bypass (CB) length, which in turn leads to enhanced weight loss and potential nutritional deficiencies due to heightened malabsorptive effects. However, a key question remains: Assuming no change in CB length, does altering BPL length affect outcomes? To address this question, we examined studies comparing long BPL and long AL (short BPL) while maintaining equal or nearly equal CB lengths. We conducted this systematic literature review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed a meta-analysis on weight loss outcomes, adverse events and safety-related outcomes, gastrointestinal complaints, and nutritional outcomes at the 2-year mark.

Metabolic and bariatric surgery in vegetarians and vegans.

Vegetarianism is constantly increasing worldwide. However, the role of metabolic and bariatric surgery (MBS) in vegetarians/vegans is unclear as there is very limited data on this topic. The aim of this study was to evaluate MBS outcomes in vegetarians or vegans. Retrospective analysis of a prospectively maintained database of a single-bariatric surgeon was carried out. All patients with a vegetarian or vegan lifestyle undergoing MBS were included. Eleven patients were included; none were lost to follow-up. Ten patients were women, the mean age and Body Mass Index (BMI) were 40.8±14 years and 43.5±4.9 kg/m2, respectively. Five patients (45%) were lacto-ovo-vegetarians, one (9%) was ovo-vegetarian, two (18%) were lacto-ovo-pesco-vegetarians, and three (27%) were vegans. Eight patients consumed vitamin supplements preoperatively, the mean albumin level was 4.1±0.2, 3/11 patients had vitamin D deficiency, 2/11 patients had vitamin-B12 deficiency, and 2/11 patients had iron deficiency. Eight patients (73%) underwent one anastomosis gastric bypass (OAGB), 2/11 patients (18%) underwent single anastomosis duodeno-ileal bypass with sleeve gastrectomy, and one patient (9%) underwent sleeve gastrectomy, the mean biliopancreatic limb length in OAGB was 225 cm. The median follow-up time was 17 months, the mean BMI and percentage of total weight loss during follow-up were 28.2±5 kg/m2 and 35.3±10.7%, respectively. The mean albumin level was 3.82±0.27, 3/11 patients had vitamin D deficiency, and 3/11 patients had iron deficiency. This study reports preliminary data on MBS outcomes in vegetarian/vegan patients. It was shown to be safe, effective, and an acceptable rate of nutritional deficiencies during follow-up. Further large cohort studies are required to clarify this data.

The Optimal Bilio Pancreatic Limb (BPL) Length in One Anastomosis Gastric Bypass (OAGB), A Systematic Review

Abstract Background The number of patients undergoing bariatric surgery for morbid obesity has progressively increased in the last 20 years worldwide. The procedures most performed nowadays are sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), accounting for 46% and 38.2% of all procedures, respectively. Among the other bariatric procedures, one anastomosis gastric bypass (OAGB) has rapidly gained acceptance and diffusion worldwide and represents 7.6% of all bariatric interventions The one anastomosis gastric bypass (OAGB) has currently gained a widespread diffusion among bariatric surgeons, being the third commonest procedure worldwide performed after sleeve gastrectomy and Roux-en-Y gastric bypass (RYGB). OAGB gained many supporters but also several criticisms for the possible onset of biliary reflux and malabsorption with consequent nutritional deficits Objective To find the most optimal length of biliopancreatic limb length in one anastomosis gastric bypass with best weight loss, outcomes and least possible malnutrition. Patients and Methods Out of the included studies, there was five Cohort study, while the remaining studies was RCT. Follow-up periods ranged between one and 12 months to 36 months. Regarding patients’ characteristics, 7343 patients were studied in the included articles. Results The rates of anemia were significantly higher in the long limb procedures due to the reduced capacity to absorb iron. However, we could not find significant differences between long and short limb procedures in the rates of iron deficiency; the small number of studies in such a comparison might have contributed to this finding. Data Sources Medline databases (PubMed, Medscape, ScienceDirect. EMF-Portal) and all materials available in the Internet till 2023. Conclusion While long limb surgery induced significantly higher weight loss than short limb procedures as indicated by %EWL and %TWL, long limb procedures were associated with multiple nutritional deficiencies, including hypoalbuminemia, hypoproteinemia, and hypocalcemia. Additionally, higher proportions of anemia and malnutrition were observed after long limb procedures compared to short limb procedures. The results should be interpreted with caution given the inherent limitations of studies’ design (primarily retrospective investigations) and the small number of studies that assessed nutritional differences over long follow-up periods. Future large- sized RCTs are required to assess the efficacy and safety of long limb procedures on weight loss and nutritional outcomes, considering the roles of BPL length, ethnic variation, gut hormonal response, and the malabsorptive paradigm of gastric bypass surgeries.

Evaluation of Biliopancreatic Limb Length in Laparoscopic One Anastomosis Gastric Bypass on Resolution of Metabolic Syndrome

Abstract Background One-anastomosis gastric bypass (OAGB) has been assessed in several studies, with most indicating excellent weight loss and improvement in comorbidities after OAGB. Aims and Objectives to compare the effect of biliopancreatic limb length (150cm versus 200cm) regarding weight loss, resolution of comorbidities and post-operative complications especially nutritional deficiency along 2 years of follow up. Subjects and Methods This Retrospective study was conducted at Ain Shams university hospital (Eldemerdash). It was carried out on 80 obese patients with type 2 diabetes mellitus who underwent laparoscopic mini gastric bypass. Result regarding Vit D3 (nmol/L) Deficiency, Ferritin (ng/mL) Deficiency, Albumin (g/dL) Deficiency, Ca (mg/dL) Deficiency, Vit B12 (pg/mL) Deficiency, PTH (pg/mL) and regarding Hyper-Parathyroidism, there was statistically significant difference between the two studied groups. there was a higher significant difference in OAGB with biliopancreatic limb length 200 cm than OAGB with biliopancreatic limb length 150 cm regarding Cholesterol and Triglycerides remission. Conclusion Results showed significant differences in Vit D3, Ferritin, albumin, calcium and Vit B12 deficiencies and Hyper-Parathyroidism. OAGB with biliopancreatic limb length 150 cm was as effective in weight loss and duration of DM, but had a higher significant difference in cholesterol and triglycerides remission.

Effect of tailoring biliopancreatic limb length based on total small bowel length versus standard limb length in one anastomosis gastric bypass: 1-year outcomes of the TAILOR randomized clinical superiority trial.

Tailoring the biliopancreatic limb length in one anastomosis gastric bypass is proposed as beneficial in retrospective studies, yet randomized trials are lacking. The aim of this double-blind, single-centre RCT was to ascertain whether tailoring biliopancreatic limb length based on total small bowel length (TSBL) results in superior outcomes after one anastomosis gastric bypass compared with a fixed 150 cm biliopancreatic limb length. Eligible patients, meeting International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) criteria for metabolic bariatric surgery, scheduled for primary one anastomosis gastric bypass surgery, and willing to be randomized, underwent TSBL measurement during surgery. When TSBL measurement was feasible, patients were randomly assigned to a standard 150 cm biliopancreatic limb length or a tailored biliopancreatic limb based on TSBL: TSBL less than 500 cm, biliopancreatic limb 150 cm; TSBL 500-700 cm, biliopancreatic limb 180 cm; and TSBL greater than 700 cm, biliopancreatic limb 210 cm. The primary outcome was percentage total weight loss at 5 years. Between September 2020 and August 2022, 212 patients were randomized into the standard biliopancreatic limb group (105 patients) or the tailored biliopancreatic limb group (107 patients). The mean(s.d.) TSBL was 657(128) cm (range 295-1020 cm). In the tailored group, 150, 180, and 210 cm biliopancreatic limb lengths were applied to 8.4%, 53.3%, and 38.3% of patients respectively. The mean(s.d.) 1-year percentage total weight loss was 32.8(6.9)% in the standard group and 33.1(6.2)% in the tailored group (P = 0.787). Nutritional deficiencies and short-term complications showed no significant differences. Tailoring biliopancreatic limb length based on TSBL is safe and feasible. One year after surgery, it is not superior to a standard biliopancreatic limb length of 150 cm in terms of percentage total weight loss. Dutch Trial Register, NL7945.

The length of the biliopancreatic limb in one anastomosis gastric bypass.

The one-anastomosis gastric bypass (OAGB), first published by Dr Rutledge in 1997 is now a well-established procedure in the bariatric-metabolic armamentarium. This procedure based on a (single) loop gastro-jejunal anastomosis (the biliopancreatic limb or BPL) with a long narrow gastric pouch combines restriction with hypo-absorption. The biliopancreatic limb and in particular its length is held responsible for the degree of the hypo-absorptive effect but the most appropriate or "optimal" length of the BPL remains debatable. The following text is based on a comprehensive and meticulous selection of the most recent literature in Cochrane, Pubmed and Google Scholar using the search terms "biliopancreatic limb", "biliopancreatic limb in one anastomosis gastric bypass" in an attempt to define not only the most common used biliopancreatic limb length but also to find out If there is an "ideal" limb length not only to optimize the outcomes of the OAGB in terms of weight loss and resolution of obesity-related diseases but also to reduce the potential side-effects in particular nutritional deficiencies. Until today there is no consensus about the "standard" or "ideal" length of the biliopancreatic limb in OAGB, a fixed length of 200 cm is still the most common used procedure although many reports and studies are in favour of shorter limb lengths adjusted to the BMI or the total small bowel length. The "ideal" or "optimal" biliopancreatic limb length in OAGB still needs to be defined. There are different options and all of them have their credits, the question remains if a consensus can be reached regarding the best strategy to obtain the best outcome.

The Impact of Longer Biliopancreatic Limb Length on Weight Loss and Comorbidity Improvement at 5 Years After Primary Roux-en-Y Gastric Bypass Surgery: A Population-Based Matched Cohort Study

IntroductionDifferent limb lengths are used in Roux-en-Y gastric bypass (RYGB) surgery, as there is no consensus which limb length strategy has the best outcomes. The biliopancreatic limb (BPL) is thought to play an important role in achieving weight loss and associated comorbidity resolution. The objective of this study was to assess the impact of a longer BPL on weight loss and comorbidity improvement at 5 years after primary RYGB.MethodsAll patients aged ≥ 18 years undergoing primary RYGB between 2014–2017 with registered follow-up 5 years after surgery were included. Long BPL was defined as BPL ≥ 100 cm and short BPL as BPL < 100 cm. The primary outcome was achieving at least 25% total weight loss (TWL) at 5 years. Secondary outcomes included absolute %TWL and improvement of comorbidities. A propensity score matched logistic and linear regression was used to estimate the difference in outcomes between patients with long and short BPL.ResultsAt 5 years, long BPL had higher odds to achieve ≥ 25% TWL (odds ratio (OR) 1.19, 95% confidence interval (CI) [1.01 – 1.41]) and was associated with 1.26% higher absolute TWL (β = 1.26, 95% CI [0.53 – 1.99]). Furthermore, long BPL was more likely to result in improved diabetes mellitus (OR = 2.17, 95% CI [1.31 – 3.60]) and hypertension (OR = 1.45, 95% CI [1.06 – 1.99]).ConclusionPatients undergoing RYGB with longer BPL achieved higher weight loss and were more likely to achieve improvement of comorbidities at 5 years.Graphical

620 Outcomes of One Anastomosis Gastric Bypass Conversion to Roux-en-Y Gastric Bypass for Morbid Obesity: A Systematic Review and Meta-Analysis

Abstract Introduction One anastomosis or ‘mini’ gastric bypass (OAGB) is a highly effective procedure to treat morbid obesity. However, conversion to Roux-en-Y gastric bypass (RYGB) for OAGB-related complications such as bile reflux is increasing. We therefore conducted the first systematic review to determine the weight outcomes, safety and efficacy associated with OAGB-RYGB conversion surgery. Method A systematic search was conducted by three independent reviewers using Medline, Embase and the Cochrane library following PRISMA guidelines. Data extracted included patient demographics, weight, and reflux outcomes. Risk of bias was assessed using the Newcastle-Ottawa scale. The mean BMI difference was analysed using a random effects model. This study was registered on PROSPERO (Registration ID: CRD42022379759). Results 6 studies were selected which included data from 134 patients undergoing OAGB-RYGB conversion surgery. Follow-up ranged from 6-60 months. Patients' baseline BMI at conversion was 30.2 (S.D. 2.85). Common indications for conversion surgery were reflux (47.8%), malnutrition (31.3%) and inadequate weight loss (8.2%). Biliopancreatic limb length ranged from 50-200cm. Weighted mean of study outcomes demonstrated biliary reflux symptoms resolved in 90.9% cases (95 % CI 78.8-n100%). Studies reporting BMI at &amp;gt;24 months reported overall stable medium-term weight (mean BMI difference -0.71 (-4.03-2.61)) with moderate study heterogeneity (I2 = 82%). The rate of major post-op complications was 14.7% (6.25%-23.1%). Conclusions OAGB to RYGB conversion surgery is associated with a high resolution of reflux symptoms. However, it is associated with weight regain, albeit this may be acceptable to patients to treat biliary reflux as the weight gain is small and stable over the long-term.

An alternative combined revision of Roux-en-Y gastric bypass: Cover all aspects (of failure)!

The revisional surgical techniques for managing weight regain after laparoscopic Roux-en-Y gastric bypass have lacked a clear gold standard. Various methods such as pouch minimising, gastroenterostomy narrowing and distalization have been described, but none have consistently achieved optimal success. This study introduces a combined revision technique that enables the reassessment of both alimentary limb and biliopancreatic limb lengths based on the individual patient's total bowel length. This approach aims to promote effective weight loss while minimising the pouch and gastroenterostomy.

Metabolic outcomes in obese mice undergoing one-anastomosis gastric bypass (OAGB) with a long or a short biliopancreatic limb.

One-anastomosis gastric bypass (OAGB) has gained importance as a simple, safe, and effective operation to treat morbid obesity. We previously found that Roux-en-Y gastric bypass surgery with a long compared with a short biliopancreatic limb (BPL) leads to improved weight loss and glucose tolerance in obese mice. However, it is not known whether a long BPL in OAGB surgery also results in beneficial metabolic outcomes. Five-week-old male C57BL/6J mice fed a high-fat diet (HFD) for 8 weeks underwent OAGB surgery with defined BPL lengths (5.5 cm distally of the duodenojejunal junction for short and 9.5 cm for long BPL), or sham surgery combined with caloric restriction. Weight loss, glucose tolerance, obesity-related comorbidities, endocrine effects, gut microbiota, and bile acids were assessed. Total weight loss was independent of the length of the BPL after OAGB surgery. However, a long BPL was associated with lower glucose-stimulated insulin on day 14, and an improved glucose tolerance on day 35 after surgery. Moreover, a long BPL resulted in reduced total cholesterol, while there were no differences in the resolution of metabolic dysfunction-associated steatotic liver disease (MASLD) and adipose tissue inflammation. Tendencies of an attenuated hypothalamic-pituitary-adrenal (HPA) axis and aldosterone were present in the long BPL group. With both the short and long BPL, we found an increase in primary conjugated bile acids (pronounced in long BPL) along with a loss in bacterial Desulfovibrionaceae and Erysipelotrichaceae and simultaneous increase in Akkermansiaceae, Sutterellaceae, and Enterobacteriaceae. In summary, OAGB surgery with a long compared with a short BPL led to similar weight loss, but improved glucose metabolism, lipid, and endocrine outcomes in obese mice, potentially mediated through changes in gut microbiota and related bile acids. Tailoring the BPL length in humans might help to optimize metabolic outcomes after bariatric surgery.NEW & NOTEWORTHY Weight loss following OAGB surgery in obese mice was not influenced by BPL length, but a longer BPL was associated with improved metabolic outcomes, including glucose and lipid homeostasis. These changes could be mediated by bile acids upon altered gut microbiota. Further validation of these findings is required through a randomized human study.

Enteroendocrine Reprogramming by Altered Epithelial-Mesenchymal Crosstalk in Metabolic Surgery.

Metabolic surgery is an effective treatment option for type 2 diabetes. However, the therapeutic scope has been limited by unexpected inconsistent outcomes. This study aims to overcome these obstacles by determining fundamental mechanisms from a novel perspective by analyzing and comparing the surgical anatomy, clinical characteristics, and outcomes of metabolic surgery, including duodenal-jejunal bypass, Roux-en-Y gastric bypass, biliopancreatic diversion, one anastomosis gastric bypass, and their modified procedures, predominantly focusing on nonobese patients to mitigate confounding effects from overweighted type 2 diabetes. Regional epithelial cell growth and unique villus formation along the anterior-posterior axis of the small intestine depend on crosstalk between the epithelium and the underlying mesenchyme. Due to altered crosstalk between the epithelium and the opposite mesenchyme at the anastomotic site, the enteroendocrine lineage of the distal intestine is replaced by the proximal epithelium after the bypass procedure. Subsequent intestinal compensatory proliferation accelerates the expansion of the replaced epithelium, including enteroendocrine cells. The primary reasons for unsatisfactory results are incomplete duodenal exclusion and insufficient biliopancreatic limb length. We anticipate that this novel mechanism will have a significant impact on metabolic surgery outcomes and provide valuable insight into optimizing its effectiveness in type 2 diabetes.

IBC-Oxford University2023_BJSPoster_3Mini-Gastric Bypass, One Anastomosis Gastric Bypass, Tailored Biliopancreatic, Bypass vs. Weight Loss

Abstract Introduction Studies of different Bariatric procedures have resulted in conflicting findings on the effects of the surgery on daily Dietary Food Choices (DFCs.) Some suggest a pure volume effect, others report changes in type and preferences and still others suggest the effects change over time. The Biliopancreatic Limb (BPL) length in the One Anastomosis Gastric Bypass (OAGB), Mini-Gastric Bypass-Original Technique (MGB-OT) version, includes a "tailored" BPL length. The purpose of this study was to investigate the relationship between BPL length and DFCs in patients undergoing MGB-OT. The primary hypothesis was that the changes in dietary habits and food choices would be related to the BPL length in the MGB-OT. Methods Data from a long term online patient survey including MGB-OT patients were collected including basic demographics, MGB-OT BPL length, patient reported DFCs and weight loss classes. Linear regression modelling was used to assess the relative association between BPL length with various mean patient reported DFCs and a composite model of Food Choices. Results 286 patients had responses for evaluation. Patients with BPL lengths of 3 to 9 ft (92-274cm) were selected. As reported in prior publications, patient reported mean weight loss classes varied linearly related to BPL length. The mean "Bad" Food Choices (BFC) declined from 5.7/day to 2.0/day. The mean composite "Bad" food choices declined from a mean of 2,070 DFCs per year to an estimated 745. There was a strong linear relation between BPL length and the decline in mean "Bad" daily food choices. (y=-0.3x-3, R2 = 0.7, p&amp;lt;0.05.) Conclusions The present study of mean patient reported DFC outcomes following a "Tailored" BPL length in the MGB-OT version of the OAGB declined substantially. The patient dietary food choices for fried foods, sugar sweetened beverages, processed meats and junk foods all declined. These changes were linearly related to the Bilio-pancreatic limb length. In cases of the MGB-OT a longer Bilio-pancreatic Limb Length was associated with greater weight loss and a greater improvement in daily Dietary Food Choices. If confirmed by other studies the possibility of tailoring the power of a bariatric operation based upon BPL length seems like an important advancement in bariatric surgery.