Laparoscopic Roux-en-Y versus mini-gastric bypass for the treatment of morbid obesity: a prospective randomized controlled clinical trial

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

BACKGROUND

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.

OBJECTIVE

This review aims to analyse the current trends and evidence regarding different BPL lengths in OAGB and their impact on outcomes.

METHODS

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.

RESULTS

There appears to be a direct relationship between length of the BPL and the incidence of malnutrition. Longer BPL lengths (> 200 cm) are associated with a higher risk of malnutrition. Shorter BPL lengths (150-200 cm), particularly 150 cm, have shown promising outcomes.

CONCLUSION

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 (< 150 cm).

Long-Term Outcome of One-Anastomosis Gastric Bypass: 10-Year Follow-Up of a Single Institution Series

BACKGROUND

This study aims to evaluate the long-term efficacy, safety, nutritional status, and resolution of obesity complications of patients following one-anastomosis gastric bypass (OAGB).

METHODS

A retrospective observational study of patients who underwent OAGB in our center between January 2011 and December 2013 was performed.

RESULTS

During the study period, 152 patients underwent OAGB procedure in our center. Among them, 26 patients were lost to follow up and therefore were excluded from the data analysis. A total of 126 patients completed long-term follow-up of 10 years. The mean age of patients at baseline was 41 ± 12.5 years (range 20-68). At 10-year follow-up, mean excess weight loss (EWL) was 68.9 ± 22.8%. Mean BMI was 29.7 ± 12.9 kg/m2, representing an overall BMI reduction of 10.6 kg/m2. At 10-year follow-up among the 126 patients, 80% had resolution in DM, 71% had resolution in HTN, and 85% had resolution in OSA. There were no instances of severe malnutrition in the 126 patients in our study.

CONCLUSIONS

OAGB is an effective choice of bariatric/metabolic surgery for patients with higher BMI which provides good weight loss in terms of % TWL and % EWL without significant recurrent weight gain or inadequate weight loss with negligible nutritional deficiencies.

Fewer patients with insufficient weight loss after one anastomosis gastric bypass compared to Roux-en-Y gastric bypass after 5 years of follow-up

This study aims to give a comprehensive overview of the one anastomosis gastric bypass (OAGB) and Roux-en-Y gastric bypass (RYGB) during 5 years of follow-up in terms of weight loss, the remission of obesity-associated diseases and complications. We performed a retrospective cohort study, with a 1:1 propensity-score matched (PSM) comparison between all adult patients who underwent a primary OAGB or RYGB in 2016. Patients with a body mass index (BMI) ≥50 kg/m2 were excluded. In total, 372 patients underwent OAGB and 113 patients RYGB. After performing a 1:1 PSM, we obtained two nearly identical cohorts of 113 patients. After OAGB, the percentage of total weight loss (%TWL) was significantly higher during 5 years of follow-up. Also, more patients after OAGB had a successful weight loss (TWL > 20%) after 5 years (86% vs. 72%; p = .019). The remission of obesity-associated diseases and short-term complications did not differ between both procedures. Persistent reflux was the reason for conversion to RYGB in 11.3% of the patients after OAGB. More internal herniations were seen after RYGB (10.4% vs. 1.9%; p = .010). Overall, the proportion of patients with major mid-term complications did not differ between both procedures. In conclusion, OAGB resulted in more weight reduction and especially fewer patients with insufficient weight loss during 5 years of follow-up, while remission of obesity-associated diseases remained the same.

The safety profile of one-anastomosis gastric bypass compared to Roux-en-Y gastric bypass: a Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program analysis

BACKGROUND

One anastomosis gastric bypass (OAGB) is an American Society for Metabolic and Bariatric Surgery (ASMBS)-endorsed bariatric surgery. As utilization of OAGB increases, it is important that the safety profile of OAGB be rigorously assessed.

OBJECTIVES

We studied the 30-day safety of OAGB compared to a similar gastro-jejunal anastomotic procedure, Roux-en-Y gastric bypass (RYGB).

SETTING

Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) participating bariatric centers in the United States.

METHODS

A matched case-control study was conducted of patients who underwent primary gastric bypass surgery 2021-2022, identified in the MBSAQIP database. Each patient who underwent OAGB was matched to 4 controls who underwent RYGB on age (±10), sex, race, body mass index (BMI) (±5 kg/m2), preoperative functional status, American Society of Anesthesiologists (ASA) classification, and 13 comorbidities. Univariate and multivariate regression analyses were performed.

RESULTS

A total of 1569 patients who underwent OAGB were matched to 6276 controls. Matched baseline characteristics were similar between groups. Operative time, length of stay (LOS), and overall complication rate were lower in the OAGB cohort (P < .001) with higher 30-day BMI loss percentage (P = .048). Specifically, OAGB was associated with a significantly lower bowel obstruction rate, as compared to RYGB (.1% versus 1.0%, P < .001). On logistic regression adjusting for all variables used in matching, OAGB was associated with a 27% decrease in overall complication rate (odds ratio [OR] .73, 95% confidence interval [CI] .62-.87, P < .001).

CONCLUSIONS

Although OAGB is minimally utilized, the 30-day safety profile appears favorable. As compared to RYGB, OAGB was associated with shorter operative time and LOS, and a lower complication rate, partially due to minimization of small bowel obstructions with a loop anatomy. Further evidence in the comparative long-term safety profile is still needed.

Bikini line one-anastomosis gastric bypass (BLOGB): initial report

BACKGROUND

This study introduces a new access method for one-anastomosis gastric bypass (OAGB) by placing ports at the bikini line.

OBJECTIVE

To describe our initial experience and assess the feasibility, safety, and effectiveness of this novel access.

SETTING

University Hospital.

METHODS

This prospective case-control study included 72 patients: 42 were allocated to the bikini line one-anastomosis gastric bypass (BLOGB) group, and 30 were assigned to the control group. Exclusion criteria included a history of major abdominal surgery, hiatal hernia, extensive lower abdominal adhesions, or a body mass index (BMI) exceeding 55 kg/m2.

RESULTS

The mean preoperative BMI of the study sample was 40.01 ± 2.84. Weight loss was satisfactory, with the highest percent excess weight loss (%EWL) observed at 12 months: 90.88 ± 7.90 and 91 ± 7.11 (p = 0.474) in both groups, respectively. Both groups showed no significant differences in operative complications, hospital stay, weight loss, or resolution of obesity-associated diseases. However, the BLOGB patients had a longer mean operative time of 110.71 ± 17.72 min compared to 98 ± 18.27 min in the control group (p = 0.002). Moreover, they experienced less postoperative pain and reported greater satisfaction with the appearance of their scars.

CONCLUSION

BLOGB was found to be potentially feasible, safe, and effective, offering improved aesthetic outcomes and reduced postoperative pain. This approach may be suitable for a select group of patients concerned with scar appearance. However, large-scale studies are necessary to ensure that safety is not compromised in pursuit of aesthetic benefits.

Bariatric Surgery: Current Trends and Newer Surgeries

Bariatric surgery has evolved and gained in popularity as it has been recognized as the most sustainable and effective treatment for obesity and related diseases. These related diseases are significant causes of obesity related morbidity and mortality. Most bariatric procedures incorporate some component of gastric restriction with or without intestinal bypass, but the full mechanism of these procedures has yet to be elucidated. The most popular surgical procedure remains the sleeve gastrectomy over the last 10 years, while gastric bypass is also still commonly performed. We have also seen growth in revisional bariatric surgery and novel surgical procedures.

Comparative Safety and Efficacy of Roux-en-Y Gastric Bypass Versus One-Anastomosis Gastric Bypass: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Obesity has become a global epidemic, affecting both developed and developing nations. Despite extensive efforts, historical outcomes of medical interventions for obesity have been unsatisfactory. Bariatric surgeries, including sleeve gastrectomy (SG) and laparoscopic Roux-en-Y gastric bypass (RYGB), are now recognized as the primary treatment for severe obesity. However, laparoscopic one-anastomosis gastric bypass (OAGB) has emerged as a promising alternative, offering simplified procedures compared to RYGB. While OAGB's initial outcomes are optimistic, concerns about biliary reflux persist. Our systematic review aims to compare the safety and efficacy outcomes of RYGB and OAGB to inform clinical decision-making in managing obesity. We searched five databases up to February 2024. We included randomized controlled trials (RCTs) comparing RYGB and OAGB in obese patients, focusing on safety and efficacy outcomes. Data extraction covered study details, participant demographics, interventions, and outcomes related to operative details, complications, follow-up results, and weight changes. The risk of bias was assessed using the Cochrane tool. The analysis involved risk ratios for dichotomous data and mean differences for continuous data, using fixed or random effects models based on heterogeneity. Analyses were performed with Review Manager software v5.4. A total of 1057 patients were included in the analysis, sourced from 12 distinct RCTs. The analysis indicated OAGB outperformed RYGB in BMI reduction (MD = -0.69, p = 0.005), whereas RYGB was more effective in excess weight loss (MD = 6.51, p < 0.0001) and excess BMI loss (MD = 3.91, p < 0.0001). OAGB led to shorter operation times (MD = -34.89 minutes, p < 0.0001) and shorter periods of hospital stays (MD = -0.27 days, p = 0.01), along with fewer overall complications (RR = 0.58, p = 0.02) and lower incidence of upper gastrointestinal endoscopy complications (RR = 2.98, p = 0.0001). On the other hand, RYGB showed higher remission rates for dyslipidemia (RR = 0.60, p = 0.0003) and higher remissions of hypertension (RR = 0.83, p = 0.04). The majority of results were homogenous. Both OAGB and RYGB have their respective advantages and limitations. OAGB appears to offer benefits in terms of operation efficiency and early postoperative recovery, making it a potentially preferable option for patients and surgeons focused on these aspects. On the other hand, RYGB might be more suitable for patients prioritizing long-term weight loss and remission of certain comorbidities like hypertension. Ultimately, the choice between OAGB and RYGB should be made on an individual basis, considering the specific needs, conditions, and goals of each patient.

Novel Surgical Interventions for the Treatment of Obesity

Metabolic and bariatric surgery is widely recognized as the most effective and durable treatment for the disease of obesity and its associated comorbidities. In recent years, the field has seen significant advancements, introducing numerous innovative surgical options. This review aims to comprehensively examine these emerging surgical techniques, which have recently received endorsement from the American Society for Metabolic and Bariatric Surgery (ASMBS). Additionally, we will explore new technologies and methodologies supported by the latest scientific evidence. Our analysis will include a critical evaluation of the efficacy, safety, and long-term outcomes of these novel approaches, providing a detailed update on the current state of metabolic and bariatric surgery, highlighting key developments and their potential implications for clinical practice.

Nonoperative Management Strategies for Anastomotic Leaks After One Anastomosis Gastric Bypass (OAGB): A Literature Review

One Anastomosis Gastric Bypass (OAGB) has gained widespread acceptance as an effective bariatric surgery due to its relative simplicity and favorable outcomes in weight loss and metabolic improvement. However, anastomotic leaks, though uncommon, present a significant complication with the potential for severe morbidity and mortality if not managed appropriately. This review examines the range of nonoperative strategies currently employed to manage anastomotic leaks and fistulae following OAGB. The focus is on endoscopic techniques, including the use of clips, stents, suturing systems, internal drainage, vacuum therapy, and tissue sealants, which have been successfully used in various gastrointestinal surgeries. Although a proportion of patients will require surgical treatments, these strategies offer less invasive alternatives to surgical intervention and can be tailored to the specific characteristics of the leak and patient condition. However, the application of these techniques specifically for OAGB-related leaks is not as well-documented. This review lists the available evidence on these nonoperative approaches, highlighting some of their potential benefits and limitations. While these methods show promise, there is a clear need for further research to establish standardized protocols and optimize their use in the context of OAGB-related leaks and fistulae.

EFFICACY AND SAFETY OF ONE ANASTOMOSIS GASTRIC BYPASS IN SURGICAL TREATMENT OF OBESITY: SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

BACKGROUND

One anastomosis gastric bypass (OAGB) has gained prominence in the search for better results in bariatric surgery. However, its efficacy and safety compared to Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) remain ill-defined.

AIMS

To compare the efficacy and safety of OAGB relative to RYGB and SG in the treatment of obesity.

METHODS

We systematically searched PubMed, EMBASE, Cochrane Library, Lilacs, and Google Scholar databases for randomized controlled trials comparing OAGB with RYGB or SG in the surgical approach to obesity. We pooled outcomes for body mass index, percentage of excess weight loss, type-2 diabetes mellitus remission, complications, and gastroesophageal reflux disease. Statistical analyses were performed with R software (version 4.2.3).

RESULTS

Data on 854 patients were extracted from 11 randomized controlled trials, of which 422 (49.4%) were submitted to OAGB with mean follow-up ranging from six months to five years. The meta-analysis revealed a significantly higher percentage of excess weight loss at 1-year follow-up and a significantly lower body mass index at 5-year follow-up in OAGB patients. Conversely, rates of type-2 diabetes mellitus remission, complications, and gastroesophageal reflux disease were not significantly different between groups. The overall quality of evidence was considered very low.

CONCLUSIONS

Our results corroborate the comparable efficacy of OAGB in relation to RYGB and SG in the treatment of obesity, maintaining no significant differences in type-2 diabetes mellitus remission, complications, and gastroesophageal reflux disease rates.

Laparoscopic Roux-Y-gastric bypass versus laparoscopic one-anastomosis gastric bypass for obesity: clinical & metabolic results of a prospective randomized controlled trial

BACKGROUND

One anastomosis gastric bypass (OAGB) has been proposed as an effective alternative to the current standard procedure in Switzerland, Roux-en-Y gastric bypass (RYGB). Prospective data comparing both procedures are scarce. Therefore, we performed a non-inferiority randomized controlled trial assessing the effectiveness and safety of these 2 operative techniques.

METHOD

Eighty patients were randomized 1:1. OAGB consisted of a very long gastric pouch with a 200 cm biliopancreatic limb, RYGB of a 150 cm ante-colic alimentary and a 60 cm biliopancreatic limb, respectively. Primary endpoint was the percent excess weight loss (%EWL) at 12 months after surgery.

RESULTS

Mean %EWL at 12 months was 87.9% (SD24.4) in the RYGB group and 104.1% (SD24.6) in the OAGB group (p = 0.006). There was no mortality. The rate of marginal ulcers was higher in patients with OAGB compared to those with RYGB (p = 0.011), while the total number of late complications did not statistically differ between the two groups. Except for the remission of GERD, which was higher in the RYGB group compared to OAGB, there was no difference between the groups regarding the remission of comorbidities. OAGB showed improved glucose control compared to the RYGB after 1 year (p = 0.001). Furthermore, glucagon-like peptide-1 increase was significantly higher in OAGB at 6 weeks (p = 0.041) and 1 year after surgery (p = 0.029). Quality of life improved after both surgeries, without differences between the groups.

CONCLUSIONS

%EWL 1 year after surgery was higher in OAGB than in RYGB. A better glycemic control with a higher increase in GLP-1 was observed after OAGB compared to RYGB.

TRIAL REGISTRATION

This trial is registered on ClinicalTrials.gov under the identifier NCT02601092.

Laparoscopic Roux-en-Y Versus Mini-Gastric Bypass on Liver Function at 6 Months in Morbid Obesity Patients: A Cross-Sectional Study

Background: Various weight loss surgeries exist, with no absolute superiority; each has pros and cons. Due to rising bariatric surgeries globally, it's vital to investigate comparisons between two-mini gastric bypass and Roux-en-Y gastric bypass (RYGB), especially regarding their impact on liver function. Objectives: The purpose of this study was to "draw comparisons between the effects of mini gastric bypass and laparoscopic Roux-en-Y gastric bypass on liver function at 6 months among patients with morbid obesity." Methods: This cross-sectional study included 90 bariatric surgery candidates (Body Mass Index (BMI) 35 - 50) from 2018 - 2021. Forty-five had laparoscopic mini gastric bypass surgery, while 45 had Roux-en-Y gastric bypass. Demographic, anthropometric, lab, and sonographic tests were conducted at baseline, 3-, and 6-months post-surgery. Data was analyzed using SPSS. Results: In a study of 90 patients (75.6% female, mean age 38.6 ± 10.4 years), both surgeries (Mini gastric bypass (MGB) and RYGB) effectively reduced body weight, BMI, and waist circumference at 3- and 6-months post-surgery. However, MGB showed significantly higher BMI and weight loss compared to RYGB (P = 0.003). In 90 patients, both surgeries reduced weight and BMI. However, MGB showed better BMI/weight loss. LFTs (ALT, AST, ALP) remained stable after MGB but worsened at 3 months after RYGB before recovering by 6 months. Mini gastric bypass also showed better GGT improvement. Both procedures improved fatty liver grading, FBS, and HbA1C levels equally. No significant differences were observed in blood pressure, platelet count, hemoglobin, or MCV. Ferritin levels increased in both groups but were higher in RYGB. CRP was higher in RYGB at 3 months. Conclusions: Roux-en-Y gastric bypass temporarily exacerbated liver enzymes and inflammation, but MGB resulted with more weight reduction. In comparison to RYGB, MGB improved LFTs more consistently.

Asia's Growing Contribution to Obesity Surgery Research: A 40-year Bibliometric Analysis

Bariatric metabolic surgery's global research interest is growing, particularly in Asia due to its high obesity rates. This study focuses on Asia, especially China, analyzing 3904 publications (1221 from China) from 1980 to 2022. Research output accelerated until the COVID-19 pandemic, driven by economic growth and rising obesity rates. China led contributions from 2010, but Western Asia led when adjusted for population. An intra-regional research collaboration network emerged, driven by geographic proximity and similar economic environments. Keyword analysis highlighted emerging topics like "laparoscopic sleeve gastrectomy" and "non-alcoholic fatty liver disease," indicating a shift in focus. The study recommends disseminating research in top-tier journals to enhance visibility and impact.

Medium-Term Outcomes from a Series of 1000 One Anastomosis Gastric Bypass in Australia: A Case Series

PURPOSE

This study presents the short- (less than 6 months) and medium-term (6 months to 2 years) outcomes for weight loss and type 2 diabetes mellitus (T2DM) for all patients undergoing one anastomosis gastric bypass (OAGB) across multiple institutions between 2015 and 2021.

MATERIALS AND METHODS

A retrospective analysis of prospectively collected databases was performed including 1022 participants who underwent OAGB at multiple institutions by multiple surgeons between 2015 and 2021. Primary outcome was percentage total weight loss (TWL) and secondary outcomes were achieving resolution of T2DM; OAGB specific short- and medium-term complications including bile reflux, marginal ulceration and internal herniation.

RESULTS

One thousand and twenty-two patients underwent OAGB (81% primary surgery). A percentage of 34.1% (n = 349) had a preoperative diagnosis of type 2 diabetes mellitus (T2DM). Mean TWL was 33.6 ± 9%  with a T2DM remission rate of 74% at 1-year post-op. Rates of bile reflux and marginal ulceration was 1.1% (n = 11) and 1.1% (n = 11). There were no cases of internal herniation during the follow-up period.

CONCLUSION

OAGB results has echoed previously published work as being efficacious and safe in a short-medium term. The prevalence of complications, especially bile reflux is overall low in our population and no current evidence exists to support an increased risk of metaplasia or malignancy related to bile within the stomach.

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.

Effects of bariatric surgery on renal function: a retrospective cohort study comparing one-year outcomes between one-anastomosis gastric bypass and Roux-en-Y gastric bypass

BACKGROUND

Evidence on the effect of one-anastomosis gastric bypass (OAGB) on renal function is limited.

OBJECTIVE

To compare the evolution of estimated renal function observed 1 year after OAGB and Roux-en-Y gastric bypass (RYGB) in individuals with obesity.

DESIGN AND SETTING

Observational, analytical, and retrospective cohort study. Tertiary-level university hospital.

METHODS

This study used a prospectively collected database of individuals who consecutively underwent bariatric surgery. Renal function was assessed by calculating the estimated glomerular filtration rate (eGFR), according to the Chronic Kidney Disease Epidemiology Collaboration. The one-year variation in the eGFR was compared between the procedures.

RESULTS

No significant differences in age, sex, obesity-associated conditions, or body mass index were observed among individuals who underwent either OAGB or RYGB. OAGB led to a significantly higher percentage of total (P = 0.007) and excess weight loss (P = 0.026). Both OAGB and RYGB led to significantly higher values of eGFR (103.9 ± 22 versus 116.1 ± 13.3; P = 0.007, and 102.4 ± 19 versus 113.2 ± 13.3; P < 0.001, respectively). The one-year variation in eGFR was 11 ± 16.2% after OAGB and 16.7 ± 26.3% after RYGB (P = 0.3). Younger age and lower baseline eGFR were independently associated with greater postoperative improvement in renal function (P < 0.001).

CONCLUSION

Compared with RYGB, OAGB led to an equivalent improvement in renal function 1 year after the procedure, along with greater weight loss.

American Society for Metabolic and Bariatric Surgery position statement on one-anastomosis gastric bypass

The following position statement is issued by the American Society for Metabolic and Bariatric Surgery in response to inquiries made to the society by patients, physicians, society members, hospitals, health insurance payors, and others regarding one-anastomosis gastric bypass as a treatment for obesity and metabolic disease. This statement is based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. The statement may be revised in the future as more information becomes available.

Efficacy and safety of one anastomosis gastric bypass versus Roux-en-Y gastric bypass at 5 years (YOMEGA): a prospective, open-label, non-inferiority, randomised extension study

BACKGROUND

The multicentre randomised trial YOMEGA (NCT02139813) comparing the one anastomosis gastric bypass (OAGB) with the Roux-en-Y gastric bypass (RYGB) confirmed the non-inferiority of OAGB on weight loss outcomes at 24 months. We aimed to report weight loss, metabolic, and safety outcomes at 5 years.

METHODS

YOMEGA is a prospective, open-label, non-inferiority, randomised trial conducted at nine centres in France. Inclusion criteria were BMI of 40 kg/m2 or more, or 35 kg/m2 or more with comorbidities. Key exclusion criteria were severe gastro-oesophageal reflux disease or Barrett's oesophagus and previous bariatric surgery. Patients were randomly assigned (1 :1) to OAGB (one gastrojejunal anastomosis with a 200 cm biliopancreatic limb) or RYGB (with a 150 cm alimentary limb and a 50 cm biliary limb), stratified by centre, with blocks of variable size. The primary endpoint of this extension study was percentage excess BMI loss and was analysed in the per-protocol population, including patients with data who were operated on with the technique randomly assigned to them and excluding patients with major deviations from the protocol during the follow-up (change of surgical technique, death, or withdrawal of consent). Non-inferiority was concluded for the primary endpoint if the upper bound of the CI was less than the non-inferiority limit (7 percentage points). YOMEGA is registered with ClinicalTrials.gov, NCT02139813, and the 5-year follow-up of YOMEGA is registered with ClinicalTrials.gov, NCT05549271.

FINDINGS

Between May 13, 2014, and March 2, 2016, 253 patients were randomly assigned to OAGB (n=129) or RYGB (n=124), and from these patients 114 in the OAGB group and 118 in the RYGB group were included in the per-protocol analysis. In the per-protocol population, at baseline, mean age was 43·0 years (SD 10·8), mean BMI was 44·0 kg/m2 (5·6), 54 (23%) patients were male and 178 (77%) were female; 55 (27%) of 207 patients had type 2 diabetes. After 5 years, mean percentage excess BMI loss was -75·6% (SD 28·1) in the OAGB group versus -71·4% (SD 29·8) in the RYGB group, confirming non-inferiority (mean difference -4·1% [90% CI -12·0 to 3·7], p=0·0099). Remission of type 2 diabetes was similar in both groups. Nutritional status did not differ; the most common adverse event was clinical gastro-oesophageal reflux disease, occurring in 27 (41%) of 66 patients in the OAGB group versus 14 (18%) of 76 patients in the RYGB group (p=0·0030). Among serious adverse events, ten (8%) of 127 patients converted from OAGB to RYGB. 171 (68%) of 253 patients were followed up.

INTERPRETATION

OAGB was not inferior to RYGB regarding percentage excess BMI loss at 5 years with similar metabolic outcomes. The high rate of clinical gastro-oesophageal reflux disease after OAGB raises questions about its long-term consequences, which need to be further investigated.

FUNDING

Medtronic.

Roux-en-Y gastric bypass versus fundoplication for gastroesophageal reflux disease in patients with obesity results in comparable outcomes

BACKGROUND

Roux-en-Y gastric bypass and fundoplication are effective treatments for gastroesophageal reflux disease, though the optimal procedure of choice in obesity is unknown. We hypothesize that Roux-en-Y gastric bypass is non-inferior to fundoplication for symptomatic control of gastroesophageal reflux disease in patients with obesity.

METHODS

We conducted a retrospective review of a prospectively maintained quality database. Patients with a body mass index ≥of 35 who presented for gastroesophageal reflux disease and subsequently underwent Roux-en-Y gastric bypass or fundoplication were included. Perioperative outcomes and pH testing data were reviewed. Patient-reported outcomes included Reflux Symptom Index, Dysphagia, Gastroesophageal Reflux Disease-Health Related Quality of Life, and Short Form-36 scores. Data were analyzed using the Wilcoxon rank sum test.

RESULTS

Ninety-five patients underwent fundoplication (n = 72, 75.8%) or Roux-en-Y gastric bypass (n = 23, 24.2%) during the study period. All patients saw an improvement in gastroesophageal reflux disease symptoms and overall quality of life. There were no significant differences in postoperative Reflux Symptom Index, Dysphagia, or Short-Form-36 scores. Significant differences in gastroesophageal reflux disease-Health Related Quality of Life scores were seen at preoperative, 1, 2, and 5 years postoperative (P < .05), with better symptom control in the fundoplication group. No significant difference was noted in postoperative DeMeester scores or percent time pH <4. Weight loss was significantly higher in the Roux-en-Y gastric bypass group at all postoperative time points up to 5 years (P < .05).

CONCLUSION

Roux-en-Y gastric bypass and fundoplication both decrease gastroesophageal reflux disease symptoms. Subjective data shows that patients undergoing Roux-en-Y gastric bypass may complain of worse symptoms compared to patients undergoing fundoplication. Objective data notes no significant difference in postoperative pH testing. Despite previous data, offering fundoplication or Roux-en-Y gastric bypass to patients with a body mass index of ≥35 kg/m2 is appropriate. The choice of surgical approach should be more directed to patient needs and desired goals at the time of the initial clinic visit.

One Anastomosis Gastric Bypass versus Roux-en-Y Gastric Bypass: A Randomized Prospective Trial

Background and Objectives: One anastomosis gastric bypass (OAGB) and Roux-en-Y gastric bypass (RYGB) surgeries are effective methods used in bariatric surgery. There are limited randomized studies comparing these procedures over more than 2 years. Here, we aimed to compare the 3-year results of two bariatric procedures. Materials and Methods: Patients included in this randomized prospective study were compared in OAGB and RYGB groups. A total of 55 patients, aged between 18 and 65, were eligible for the study. Thirteen patients who did not accept randomization were excluded. Patients were evaluated at 6, 12, 24, and 36 months postoperatively. Results: Three patients were excluded from the study due to loss of communication during the clinical follow-up and one due to death by amyotrophic lateral sclerosis, which started in the eighth month after surgery. The study was completed with a total of 38 patients (OAGB; n = 20, RYGB; n = 18). Patients in the two groups were similar in terms of age, gender, body mass index (BMI), and obesity-related comorbidities. At the end of 3-year follow-up, BMI in the OAGB and RYGB groups was 28.80 ± 4.53 kg/m2 and 29.17 ± 5.36 kg/m2, respectively (p = 0.822). Percentage total weight loss (TWL%) was similar. No significant differences were found between the groups regarding percentage excess weight loss (EWL%). Remission of comorbidities was similar. De novo refluxes developed in four OAGB patients; there were no occurrences of these in RYGB patients (p = 0.066). Conclusions: Both OAGB and RYGB are effective in the treatment of morbid obesity. The two procedures are similarly successful in terms of obesity-related comorbidities.

One anastomosis gastric bypass as a primary bariatric surgery: MBSAQIP database analysis of short-term safety and outcomes

BACKGROUND

One anastomosis gastric bypass (OAGB) is described as a simpler, potentially safe, and effective bariatric-metabolic procedure that has been recently endorsed by the American Society of Metabolic and Bariatric Surgery.

OBJECTIVES

First, we aim to compare the 30-day outcomes between OAGB and other bypass procedures: Roux-en-Y gastric bypass (RYGB) and single anastomosis duodenoileal bypass with sleeve gastrectomy (SADI-S). Second, identify the odds between postoperative complications and each surgical procedure.

METHODS

Patients who underwent primary OAGB, RYGB, and SADI-S were identified using the MBSAQIP database of 2020 and 2021. An analysis of patient demographics and 30-day outcomes were compared between these three bypass procedures. In addition, a multilogistic regression for overall complications, blood transfusions, unplanned ICU admissions, readmission, reoperation, and anastomotic leak stratified by surgical procedure was performed.

RESULTS

1607 primary OAGBs were reported between 2020 and 2021. In terms of patient demographics, patients who underwent RYGB and SADI-S showed a higher incidence of comorbidities. On the other hand, OAGB had shorter length of stay (1.39 ± 1.10 days vs 1.62 ± 1.42 days and 1.90 ± 2.04 days) and operative times (98.79 ± 52.76 min vs 125.91 ± 57.76 min and 139.85 ± 59.20 min) than RYGB and SADI-S. Similarly, OAGB showed lower rates of overall complications (1.9% vs 4.5% and 6.4%), blood transfusions (0.4% vs 1.1% and 1.8%), unplanned ICU admission (0.3% vs 0.8% and 1.4%), readmission (2.4% vs 4.9% and 5.0%), and reoperation (1.2% vs 1.9% and 3.1%). A multilogistic regression analysis was performed, RYGB and SADI-S demonstrated higher odds of 30-day complications.

CONCLUSION

The incidence of primary OAGB has increased since its approval by ASMBS, from 0.05% reported between 2015 and 2019 to 0.78% between 2020 and 2021. OAGB had better 30-day outcomes and shorter operative times than RYGB and SADI-S and therefore, could be considered a viable alternative.

A systematic review and meta-analysis on GERD after OAGB: rate, treatments, and success

INTRODUCTION

This review aims to investigate the gastroesophageal reflux disease (GERD) as one of the important concerns for both surgeons and patients after one anastomosis gastric bypass (OAGB).

METHOD

PubMed, Scopus, Embase, Web of Science, and Cochrane were reviewed by the end of the 2021 with keywords relating to GERD, OAGB, and their equivalents. Data regarding OAGB, number of patients with GERD, treatment for GERD, endoscopy findings, the interval between GERD and OAGB were retrieved by two independent investigators. The primary effect/effect size measure was prevalence.

RESULTS

40 studies examining 17,299 patients were included revealing that 2% of patients experience GERD following OAGB. Reflux after revisional OAGB is six times higher than primary OAGB. Despite being unclear, medical and surgical treatments for GERD after OAGB were used in 60% and 41% of patients with estimated success rate of 85% and 100%, respectively.

CONCLUSION

Based on how GERD was identified after OAGB, its rate ranged from 0 to 55%; the pooled rate of 2% is near to Roux-en-Y gastric bypass. GERD symptoms can be mild to be tolerated without medical treatment, moderate that respond to acid-reducing agents, or severe enough that are categorized as interactable and would need a surgical intervention.

Does One-Anastomosis Gastric Bypass Expose Patients to Gastroesophageal Reflux: a Systematic Review and Meta-analysis

This systematic review and meta-analysis aimed to investigate the incidence of new-onset gastroesophageal reflux, reflux change, esophagitis, Barrett's esophagus, and revision due to reflux, gastritis, and marginal ulcer after one-anastomosis gastric bypass (OAGB). We performed subgroup analyses based on primary and revisional OAGB and time of follow-up. Meta-analysis of 87 studies with 27,775 patients showed a 6% rate of new-onset reflux after OAGB. Preoperative reflux status did not change significantly after OAGB. The rate of esophagitis and Barrett's esophagus was 15% and 1%, respectively. The new-onset reflux rate after OAGB was significantly higher than gastric bypass but not different with sleeve gastrectomy. The current study showed a relatively low rate of reflux and its complications after OAGB, but it was significantly higher than Roux-en-Y gastric bypass.

Roux-en-Y versus one-anastomosis gastric bypass (RYSA study): weight loss, metabolic improvements, and nutrition at 1 year after surgery, a multicenter randomized controlled trial

OBJECTIVE

Although it has been suggested that one-anastomosis gastric bypass (OAGB) is metabolically superior to the "gold standard," i.e., Roux-en-Y gastric bypass (RYGB), there is little robust evidence to prove it. Because this result may arise from the typically longer length of bypassed intestine in OAGB, here, the authors standardized the bypass length in RYGB and OAGB and compared weight loss and metabolic outcomes in a randomized controlled trial.

METHODS

The authors randomized 121 bariatric patients to RYGB (n = 61) or OAGB (n = 60) in two Finnish University Hospitals and measured weight; body composition; metabolic features (insulin sensitivity, lipids, inflammation, nutrition); and comorbidities before and 6 and 12 months after the operation.

RESULTS

Total weight loss was similar in RYGB and OAGB at 6 months (mean: 21.2% [95% CI: 19.4-23.0] vs. 22.8% [95% CI: 21.5-24.1], p = 0.136) and 12 months (25.4% [95% CI: 23.4-27.5] vs. 26.1% [95% CI: 24.2-28.9], p = 0.635). Insulin sensitivity, lipids, and inflammation improved similarly between the groups (p > 0.05). Remission of type 2 diabetes and hypercholesterolemia was marked and similar (p > 0.05) but the use of antihypertensive medications was lower (p = 0.037) and hypertension tended to improve more (p = 0.053) with RYGB versus OAGB at 12 months. Higher rates of vitamin D-25 deficiency (p < 0.05) and lower D-25 levels were observed with OAGB versus RYGB throughout the follow-up (p < 0.001). No differences in adverse effects were observed.

CONCLUSIONS

RYGB and OAGB were comparable in weight loss, metabolic improvement, remission of diabetes and hypercholesterolemia, and nutrition at 1-year follow-up. Vitamin D-25 deficiency was more prevalent with OAGB, whereas reduction in antihypertensive medications and hypertension was greater with RYGB. There is no need to change the current practices of RYGB in favor of OAGB.

Comparison of Single Versus Double Anastomosis Bariatric Metabolic Surgery in Obesity: a Systematic Review and Meta-analysis

Major BMS are modified through loop rather than Roux-en-Y type reconstruction recently, and this study systematically reviews the BMS from the perspective of SA (single anastomosis) and DA (double anastomosis) procedures, aiming to research the differences among bariatric procedures. A total of 39 studies compared SA- and DA-BMS were finally eligible for analysis after searching in PubMed, Web of Science, and Cochrane Library. Compared with DA, SA shortens operative time and decreases complications especially obstruction, internal hernia, and reoperation. SA-GB (gastric bypass) has significantly higher %TWL and T2DM remission rate than DA-GB 1- and 5-year postoperatively. SA-DS (duodenal switch) has similar 1-year %TWL and lower 5-year %TWL, and comparable 1- and 5-year T2DM remission with DA-DS. SA provides significant advantages about simplicity and safety. This, together with the shorter learning curve, makes SA a promising choice.

Bile reflux and marginal ulcers after one-anastomosis gastric bypass (OAGB). A narrative review

One-anastomosis gastric bypass has now become the third most commonly performed bariatric technique worldwide. However, as a consequence of the configuration of this surgery, it can present some chronic complications (anastomotic mouth ulcers and biliary reflux) that physicians must come to better understand and assess. In this narrative review, we aimed to update our knowledge of both the diagnosis and treatment of these two complications in the context of bariatric surgeries. We concluded that a series of pre-, intra-, and postoperative preventive strategies should be considered by surgeons to help reduce the appearance of these complications.

Roux-en-Y and One-Anastomosis Gastric Bypass Surgery Are Superior to Sleeve Gastrectomy in Lowering Glucose and Cholesterol Levels Independent of Weight Loss: a Propensity-Score Weighting Analysis

BACKGROUND

The superior effects of gastric bypass surgery in preventing cardiovascular diseases compared with sleeve gastrectomy are well-established. However, whether these effects are independent of weight loss is not known.

METHODS

In this retrospective cohort study, we compared the change in cardiometabolic risks of 1073 diabetic patients undergoing Roux-en-Y gastric bypass (RYGB) (n = 265), one-anastomosis gastric bypass (OAGB) (n = 619), and sleeve gastrectomy (SG) (n = 189) with equivalent weight loss from the Min-Shen General Hospital. Propensity score-weighting, multivariate regression, and matching were performed to adjust for baseline differences.

RESULTS

After 12 months, OAGB and, to a lesser extent, RYGB exhibited superior effects on glycemic control compared with SG in patients with equivalent weight loss. The effect was significant in patients with mild-to-modest BMI reduction but diminished in patients with severe BMI reduction. RYGB and OAGB had significantly greater effects in lowering total and low-density lipoprotein cholesterol than SG, regardless of weight loss. The results of matching patients with equivalent weight loss yielded similar results. The longer length of bypassed biliopancreatic (BP) limbs was correlated with a greater decrease in glycemic levels, insulin resistance index, lipids, C-reactive protein (CRP) levels, and creatinine levels in patients receiving RYBG. It was correlated with greater decreases in BMI, fasting insulin, insulin resistance index, and C-reactive protein levels in patients receiving OAGB.

CONCLUSION

Diabetic patients receiving OAGB and RYGB had lower glucose and cholesterol levels compared with SG independent of weight loss. Our results suggest diabetic patients with cardiovascular risk factors such as hypercholesterolemia to receive bypass surgery.

Marginal Ulcers Following One-Anastomosis Gastric Bypass: a Systematic Review and Meta-analysis

BACKGROUND

Marginal ulcer (MU) is an uncommon but significant complication following one-anastomosis gastric bypass (OAGB). Our study aims to understand the incidence rates, risk factors, and management of MU following OAGB.

METHODS

MEDLINE, Scopus, and Cochrane Library databases were examined to identify all studies on OAGB where authors had reported on MU. Data were collected on basic demographics, incidence rates, risk factors, and management of this condition.

RESULTS

Thirty-two studies involving 8868 patients were analysed. The mean age and body mass index (BMI) of patients in these studies were 40.9 ± 4.5 years and 47.6 ± 5.6 kg/m2, respectively. Among the patient cohort, approximately 72% were female, and 20.6% had preoperative gastroesophageal reflux disease (GERD). The authors described prescribing proton-pump inhibitors (PPI) prophylaxis to 14.1% of patients after surgery. Two hundred twenty-eight patients were reported to have MU. The incidence of MU was 2.59% (95% CI 1.89-3.52), of which 53 patients presented within 12 months, 24 patients presented after 31 months, and five patients after 6 years. One hundred forty-six patients did not have presentation time documented. Sixty-five patients were described to have MU diagnosed on endoscopy, of which 54 were symptomatic and 11 were asymptomatic. The authors were, however, not specific on the choice of investigation for the remaining 163 patients. Of patients, 89.7% were treated conservatively with PPIs, whilst 10.3% had surgery to treat MU.

CONCLUSIONS

Marginal ulcer is an uncommon complication following OAGB. The majority of patients are treated conservatively with PPIs. Larger, well-designed studies reporting on risk factors, investigation, and management of MU following OAGB are warranted.

Combined laparoscopic pouch and loop resizing as a revisional procedure for weight regain after primary laparoscopic one-anastomosis gastric bypass

Introduction

One-anastomosis gastric bypass (OAGB) presents a satisfactory long-term outcome in terms of weight loss, amelioration of comorbidities and low morbidity. However, some patients may present insufficient weight loss or weight regain. In this study, we tackle a case series evaluating the efficiency of the combined laparoscopic pouch and loop resizing (LPLR) as a revisional procedure for insufficient weight loss or weight regain after primary laparoscopic OAGB.

Materials and Methods

We included eight patients with a body mass index (BMI) ≥30 kg/m2 with a history of weight regain or insufficient weight loss after laparoscopic OAGB, who underwent revisional laparoscopic intervention by LPLR between January 2018 and October 2020 at our institution. We conducted a 2 years' follow-up. Statistics were performed using International Business Machines Corporation® SPSS® software for Windows version 21.

Results

The majority of the eight patients were males (62.5%), with a mean age of 35.25 at the time of the primary OAGB. The average length of the biliopancreatic limb created during the OAGB and LPLR were 168 ± 27 and 267 ± 27 cm, respectively. The mean weight and BMI were 150.25 ± 40.73 kg and 48.68 ± 11.74 kg/m2 at the time of OAGB. After OAGB, patients were able to reach an average lowest weight, BMI and per cent of excess weight loss (%EWL) of 89.5 ± 28.85 kg, 28.78 ± 7.47 kg/m2 and 75.07 ± 21.62%, respectively. At the time of LPLR, patients had a mean weight, BMI and %EWL of 116.12 ± 29.03 kg, 37.63 ± 8.27 kg/m2 and 41.57 ± 12.99%, respectively. Two years after the revisional intervention, the mean weight, BMI and %EWL were 88.25 ± 21.89 kg, 28.44 ± 4.82 kg/m2 and 74.51 ± 16.54%, respectively.

Conclusion

Combined pouch and loop resizing is a valid option for revisional surgery following weight regain after primary OAGB, leading to adequate weight loss through enhancement of the restrictive and malabsorptive effect of OAGB.

Fragility of statistically significant outcomes in randomized trials comparing bariatric surgeries

BACKGROUND

Randomized controlled trials (RCTs) are regarded as high-level evidence, but the strength of their P values can be difficult to ascertain. The Fragility Index (FI) is a novel metric that evaluates the frailty of trial findings. It is defined as the minimum number of patients required to change from a non-event to event for the findings to lose statistical significance. This study aims to characterize the robustness of bariatric surgery RCTs by examining their FIs.

METHODS

A search was conducted in MEDLINE, EMBASE, and CENTRAL from January 2000 to February 2022 for RCTs comparing two bariatric surgeries with statistically significant dichotomous outcomes. Bivariate correlation was conducted to identify associations between FI and trial characteristics.

RESULTS

A total of 35 RCTs were included with a median sample size of 80 patients (Interquartile range [IQR] 58-109). The median FI was 2 (IQR 0-5), indicating that altering the status of two patients in one treatment arm would overturn the statistical significance of results. Subgroup analyses of RCTs evaluating diabetes-related outcomes produced a FI of 4 (IQR 2-6.5), while RCTs comparing Roux-en-Y gastric bypass and sleeve gastrectomy had an FI of 2 (IQR 0.5-5). Increasing FI was found to be correlated with decreasing P value, increasing sample size, increasing number of events, and increasing journal impact factor.

CONCLUSION

Bariatric surgery RCTs are fragile, with only a few patients required to change from non-events to events to reverse the statistical significance of most trials. Future research should examine the use of FI in trial design.

Current treatment landscape for obesity in Singapore

The rising prevalence of obesity in Singapore is a harbinger for a corresponding increase in obesity-related complications such as type 2 diabetes mellitus (T2DM) and coronary heart disease. Obesity is a complex disease driven by multiple factors, and hence, treatment cannot follow a 'one-size-fits-all' approach. Lifestyle modifications involving dietary interventions, physical activity and behavioural changes remain the cornerstone of obesity management. However, similar to other chronic diseases such as T2DM and hypertension, lifestyle modifications are often insufficient on their own, hence the importance of other treatment modalities including pharmacotherapy, endoscopic bariatric therapy and metabolic-bariatric surgery. Weight loss medications currently approved in Singapore include phentermine, orlistat, liraglutide and naltrexone-bupropion. In recent years, endoscopic bariatric therapies have evolved as an effective, minimally invasive and durable therapeutic option for obesity. Metabolic-bariatric surgery remains the most effective and durable treatment for patients with severe obesity, with an average weight loss of 25%-30% after one year.

One Anastomosis Gastric Bypass (OAGB) vs Roux en Y Gastric Bypass (RYGB) for Remission of T2DM in Patients with Morbid Obesity: a Randomized Controlled Trial

INTRODUCTION

Majority of the studies comparing Roux en Y gastric bypass (RYGB) and one anastomosis gastric bypass (OAGB) are non-randomized. Moreover, few randomized studies have focussed on weight loss as the primary outcome rather than the impact on type 2 diabetes mellitus (T2DM). This randomized trial compared OABG over RYGB with the hypothesis that OAGB is not inferior to RYGB in terms of remission of T2DM.

METHODS

This was an open-labelled, randomized trial in which patients having a BMI greater than 30 kg/m² with T2DM were included. The primary outcome was the remission of T2DM.

RESULTS

In the study, 25 and 24 patients were recruited in OAGB and RYGB groups respectively. The remission rates of T2DM were similar at all timelines. The highest rate was achieved at 1 year (86.36% vs 85.71%) for both the groups and a 4-year remission rate of (72.22% vs 71.43%), for OAGB vs RYGB respectively. The % EWL was also comparable with the highest rate achieved again at 1 year (69.23% vs 66.67%) and a 4-year rate of (58.33% vs 53.33%), for OAGB vs RYGB respectively. Remission of other co-morbidities, major and minor complication rate, re-admission rate, and nutritional issues were similar in both groups.

CONCLUSION

OAGB is non-inferior to RYGB in terms of remission of type 2 diabetes mellitus, weight loss, and early and late complications with a shorter operating time.

Outcomes of laparoscopic revisional conversion of sleeve gastrectomy to Roux-en-Y gastric bypass: Diff erent strategies for obese and non-obese Asian patients

BACKGROUND

Sleeve gastrectomy (SG) is the most performed bariatric procedure now. Some patients would necessitate a revision to Roux-en-Y gastric bypass (RYGB) as a salvage procedure for intractable gastroesophageal reflux disease (GERD). However, outcome of the revision in Asians with co-existed obesity and those non-obese is not clear.

METHODS

We retrospectively reviewed the data of patients who underwent revisional laparoscopic RYGB after SG between 2007 and 2019 for intractable GERD with data of one year follow-up. Pre-operative clinical data, perioperative outcomes, GERD symptoms, weight loss and medication details were analyzed. Patients were classified into those with body mass index (BMI) ≥ 25 and < 25 kg/m².

RESULTS

Fifty-five patients (44 women, 11 men; mean age 42.5 years) were included. Mean interval from the initial SG to revision surgery was 51.2 months (range, 5-132). Mean body mass index before SG was 34.6 kg/m², whereas that before revision surgery was 27.6 kg/m². All the patients required continue proton pump inhibitor (PPI) to control the GERD symptoms before surgery. Among them, 36 (65.4%) patients in the obese group received long BP limb (>100 cm) RYGB for associated obesity but the common channel was assured to ≥ 400 cm or 70% of small bowel length, the other 19 (34.6%) patients in the non-obese group received standard BP limb (<100 cm) RYGB. There was no difference in basic characters between the two groups before revision surgery except a higher mean BMI (30.0 vs. 22.2 kg/m², p < 0.001), blood pressure and triglyceride in obese group. One year after revision surgery, all the patients had improved GERD symptoms but only 33 (60%) can completely wave PPI, without difference between the 2 groups. Obese group with a long BP limb RYGB had a significant higher % total weight loss (TWL) than non-obese group (%TWL 9.1% vs. -3.1%, p = 0.005).

CONCLUSION

Laparoscopic revision to RYGB is a safe and effective treatment for patients with intractable GERD after SG but some patients may still have residual GERD symptoms. Using a modified RYGB technique in revision surgery may help in weight reduction for obese Asian patients.

Revisional Single-Anastomosis Gastric Bypass for a Patient With Severe Protein-Calorie Malnutrition: A Case Report

Obesity is a chronic disorder with numerous manifestations as well as pandemic occurrence on a global scale. One-anastomosis gastric bypass (OAGB) is a safe and effective surgical procedure for the treatment of obesity and metabolic diseases. Revision surgery may be necessary due to postoperative issues, such as protein-calorie deficiency, weight increase, or inadequate weight loss. This case describes a 40-year-old female patient who came to our service due to protein-caloric malnutrition, with a history of OAGB. The patient underwent revision surgery for OAGB reversal. One year after surgery the patient had a body mass index (BMI) of 25; today she is healthy, consumes a regular diet, and has no associated complications.

Efficacy and Safety of One Anastomosis Gastric Bypass Versus Roux-en-Y Gastric Bypass for Obesity: a Meta-analysis and Systematic Review

The objective of this review is to systematically review the efficacy and safety outcomes of one anastomosis gastric bypass (OAGB) with Roux-en-Y gastric bypass (RYGB). From inception to July 4, 2022, a systematic literature search was performed using PubMed, Embase, and Cochrane Library for randomized clinical trials comparing OAGB with RYGB in obesity. A meta-analysis performed using the RevMan 5.4.1 software evaluations was completed. We identified 1217 reports; after exclusions, eight trials with a total of 931 patients were eligible for analysis. Compared with RYGB, OAGB had multiple advantageous indexes. Examples include percent of excess weight loss (%EWL) at 12 months (P = 0.009), body mass index (BMI) at 2 years (P < 0.00001), early postoperative complication (P = 0.04), remission of dyslipidemia (P < 0.0001), and operative time (P < 0.00001). No significant statistical difference was observed in BMI at 6 months, %EWL at 6 months, BMI at 12 months, percent of excess body mass index loss (%EBMIL) at 2 years, BMI at 5 years, intraoperative complications, late postoperative complications, remission of type 2 diabetes mellitus, and dyslipidemia or gastroesophageal reflux disease remission between OAGB and RYGB. OAGB is no less effective than RYGB; no significant differences in weight loss efficacy were observed, and more large and long-term randomized controlled trials are needed to verify this. In addition, studies have shown that OAGB has a shorter operation time, fewer early postoperative complications, and a shorter learning curve, making it easier for young surgeons to perform.

Common, Less Common, and Unexpected Complications after Bariatric Surgery: A Pictorial Essay

Bariatric surgery has demonstrated a higher rate of success than other nonsurgical treatments in selected patients with obesity; however, like all medical procedures, postoperative complications may occur, ranging between 2 and 10% and, although rare, they can be life threatening. Complications may be unspecific (any surgery-related complications) or specific (linked to the specific surgical procedure) and can be distinguished as common, less common, and unexpected. According to the onset, they may be acute, when occurring in the first 30 days after surgery, or chronic, with a presentation after 30 days from the procedure. The aim of this pictorial essay is to review the radiological aspects of surgical techniques usually performed and the possible complications, in order to make radiologists more confident with the postsurgical anatomy and with the normal and abnormal imaging findings.

The effects of laparoscopic Roux-en-Y gastric bypass and one-anastomosis gastric bypass on glycemic control and remission of type 2 diabetes mellitus: study protocol for a multi-center randomized controlled trial (the DIABAR-trial)

Background

Metabolic surgery induces rapid remission of type 2 diabetes mellitus (T2DM). There is a paucity of high level evidence comparing the efficacy of the laparoscopic Roux-en-Y gastric bypass (RYGB) and the laparoscopic one-anastomosis gastric bypass (OAGB) in glycemic control. Also, the mechanisms that drive the conversion of T2DM in severe obese subjects to euglycemia are poorly understood.

Methods

The DIABAR-trial is an open, multi-center, randomized controlled clinical trial with 10 years follow-up which will be performed in 220 severely obese patients, diagnosed with T2DM and treated with glucose-lowering agents. Patients will be randomized in a 1:1 ratio to undergo RYGB or OAGB. The primary outcome is glycemic control at 12 months follow-up. Secondary outcome measures are diverse and include weight loss, surgical complications, psychologic status and quality of life, dietary behavior, gastrointestinal symptoms, repetitive bloodwork to identify changes over time, glucose tolerance and insulin sensitivity as measured by mixed meal tests, remission of T2DM, presence of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis in liver biopsy, oral and fecal microbiome, cardiovascular performance, composition of bile acids, and the tendency to develop gallstones.

Discussion

The DIABAR-trial is one of the few randomized controlled trials primarily aimed to evaluate the glycemic response after the RYGB and OAGB in severe obese patients diagnosed with T2DM. Secondary aims of the trial are to contribute to a deeper understanding of the mechanisms that drive the remission of T2DM in severe obese patients by identification of microbial, immunological, and metabolic markers for metabolic response and to compare complications and side effects of RYGB and OAGB.

Trial registration

ClinicalTrials.gov NCT03330756; date first registered: October 13, 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06762-3.

From surgery to endoscopy: the evolution of the bariatric discipline

ABSTRACT

Obesity, with its increasing morbidity and prevalence, is now a worldwide public health problem. Obesity and its related comorbidities impose a heavy burden on societal health and the economy. The practice of bariatric surgery has evolved from its early surgical procedures, many of which are no longer routine operations. With clinical practice, research, and experience, bariatric surgery has gradually become an important last resort for the control of weight and obesity-related metabolic diseases in moderately and severely obese patients. However, there is still room for further improvements in bariatric surgical procedures, especially with regard to long-term issues and complications. Endoscopic weight loss technology has developed rapidly in recent years. The advantages of this technology include minimal invasiveness, an obvious weight loss effect, and few complications, thus filling the gap between medications and lifestyle adjustments and surgical treatment of obesity. Endoscopic weight loss technology may even replace surgical bariatric procedures. This review summarized the current status of bariatric metabolic surgery and newly developed bariatric endoscopic procedures.

Surgical Management of Gastro-oesophageal Reflux Disease After One Anastomosis Gastric Bypass - a Systematic Review

Gastro-oesophageal reflux disease (GORD) after one anastomosis gastric bypass (OAGB) remains a concern. We reviewed the current literature on revisional surgery after OAGB for GORD. MEDLINE, EMBASE, and PubMed databases were searched. We identified 21 studies, appraising 13,658 OAGB patients. A total of 230 (1.6%) patients underwent revisional surgery for GORD. Revision to Roux-en-Y configuration was performed in 211 (91.7%) patients. Six (2.6%) patients had a Braun entero-enterostomy added to the OAGB. Thirteen (5.6%) patients underwent excluded stomach fundoplication (ESF). Reflux symptoms resolved in 112 (48.6%) patients, persisted in 13 (5.6%) patients, and were not reported in 105 (45.6%) patients. Revisional surgery after OAGB for GORD appears to be rare, and when required, conversion to Roux-en-Y configuration is the commonest choice.

Efficacy and safety of one anastomosis gastric bypass versus Roux-en-Y gastric bypass for type 2 diabetes remission (ORDER): protocol of a multicentre, randomised controlled, open-label, superiority trial

INTRODUCTION

Previous studies have demonstrated that one anastomosis gastric bypass (OAGB) is not inferior to Roux-en-Y gastric bypass (RYGB) in treating obesity. However, high level evidence comparing the efficacy and safety of both procedures in type 2 diabetes (T2D) treatment is still lacking, which is another main aim of bariatric surgery. The presented trial has been designed to aim at investigating the superiority of OAGB over the reference procedure RYGB in treating T2D as primary endpoint. And diabetes-related microvascular and macrovascular complications, cardiovascular comorbidities, weight loss, postoperative nutritional status, quality of life and overall complications will be followed up for 5 years as secondary endpoints.

METHODS AND ANALYSIS

This prospective, multicentre, randomised superiority open-label trial will be conducted in patients of Asian descent. A total of 248 patients (BMI≥27.5 kg/m²) who are diagnosed with T2D will be randomly assigned (1:1) to OAGB or RYGB with blocks of four. The primary endpoint is the complete diabetes remission rate defined as HbA1c≤6.0% and fasting plasma glucose≤5.6 mmol/L without any antidiabetic medications at 1 year after surgery. All secondary endpoints will be measured at different follow-up visit points, which will start at least 3 months after enrolment, with a continuous annual follow-up for five postoperative years in order to provide solid evidence on the efficacy and safety of OAGB in patients with T2D.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee of leading centre (Beijing Friendship Hospital, Capital Medical University, no. 2021-P2-037-03). The results generated from this work will be disseminated to academic audiences and the public via publications in international peer-reviewed journals and conferences. The data presented will be imported into a national data registry. Findings are expected to be available in 2025, which will facilitate clinical decision-making in the field.

TRIAL REGISTRATION NUMBER

NCT05015283.

Natural Orifice Transluminal Endoscopic One-Anastomosis Gastric Bypass: a Feasibility Study Using Human Cadavers

BACKGROUND

Endoscopic bariatric therapies (EBT) has emerged as an effective treatment in the management of the patient with obesity. Unfortunately, most procedures involve only the restriction of gastric volume without altering the underlying metabolism. The objective of this study was to investigate the practicability and limitations of the metabolic altering procedures: "One anastomosis gastric bypass (OAGB)" with "natural orifice transluminal endoscopic surgery (NOTES)" on human cadavers.

METHODS

We performed OAGB with NOTES approach in 3 human cadavers. The steps of the procedure can be divided as follows: step 1, endoscopic sleeve gastroplasty (ESG); step 2, trans-gastric access to peritoneal cavity; step 3, identification of suitable loop of jejunum; step 4, introduction of the jejunal loop into the stomach; step 5, creation of the gastro-jejunostomy with lumen-apposing metal stent (LAMS); step 6, gastric pylorus occlusion with overstitch.

RESULTS

We performed OAGB with NOTES in 3 human cadavers with bypassed bilio-pancreatic limb of 55, 75, and 105 cm from the pylorus. The average weight for the cadavers was 64.9 kg (61.2-71.7 kg). The mean procedure time was 157 min. The optimal bypassed length for the procedure was 105 cm.

CONCLUSIONS

This study has provided proof-of-principle in a pre-clinical cadaveric model that NOTES approach can be used to perform OAGB and, therefore, merits additional evaluation and consideration in surviving porcine model.

The United States Experience with One Anastomosis Gastric Bypass at MBSAQIP-Accredited Centers

PURPOSE

One anastomosis gastric bypass (OAGB) has emerged as a potentially safe and effective weight-loss procedure. Worldwide, OAGB is the third most commonly performed primary bariatric procedure, comprising 4% of the annual volume. In the USA, OAGB has yet to be endorsed as a primary bariatric procedure and can only be performed under research protocols or as a revision procedure.

MATERIALS AND METHODS

We performed an observational cohort study to describe the preoperative, intraoperative, and postoperative characteristics of adult patients who underwent primary or revision OAGB from 2015 to 2019 at MBSAQIP centers. Exclusion criteria included emergent surgery, incomplete 30-day follow-up, and non-laparoscopic- or robotic approach.

RESULTS

During the study period, 803,906 bariatric procedures were performed and 645 (0.08%) were OAGB. Among these, 436 (67.6%) were primary and 209 (32.4%) were revision OAGB. The mean operation time was 89 min (SD, 59) and 8% were performed using a robotic approach. The overall complication rate was 7.4% and there was one death (0.2%). The post-operative complication rates were generally higher than the early complication rate (3.4%) reported in the YOMEGA trial, an RCT from France. Revision OAGB had a longer mean operation time of 141 min (SD, 85, p < 0.001).

CONCLUSION

Primary OAGB was a rarely performed bariatric procedure at MBSAQIP-accredited centers comprising only 0.05% compared to 4% worldwide. Future studies should compare safety of OAGB to that of established bariatric procedures like Roux-en-Y gastric bypass and sleeve gastrectomy.

Experience of the First 100 OAGB in China: OAGB In Situ Technique

Background

One anastomosis gastric bypass (OAGB) is gradually accepted worldwide but still new in China.

Materials and Methods

Retrospective review of the patients who received OAGB in a new bariatric/metabolic surgical center in China and compared the data with a center of excellence in Taiwan. All in-patient and outpatient follow-up data were analyzed. The main outcome measures were (1) operation risk (2) weight loss (3) diabetes remission.

Results

Between August 2019 and October 2021, 100 consecutive patients who received OAGB in situ in China and 225 patients who received OAGB with the same technique were recruited from Taiwan. Taiwan patients were older (39.2 ± 10.6 vs. 33.3 ± 8.8 years old, p < 0.001), and to have more diabetes (32.4% vs. 20.0%, p = 0.022) comparing to the patients of China. Operation time was significantly longer for Taiwan patients (172.4 ± 36.9 vs. 128.5 ± 29.8, p < 0.001). Taiwan patients lost more blood during the operation (35.5 ± 25.2 vs. 22.4 ± 15.6, p < 0.001) but patients in China need more time to postoperative flatus passage (1.3 ± 0.5 vs. 2.0 ± 0.5, p < 0.001). There was no major surgical complication in this study, minor complication rates were similar low for both groups (1.0% vs. 1.8%, p = 0.891). At 1 year after surgery, %TWL and %EWL of both centers were similar (33.9 ± 7.43% vs. 32.6 ± 11.2%, p = 0.91; 81.9 vs. 19.8 vs. 85.4 ± 13.2, p = 0.798). T2DM remission (HbA1c < 6.5%) was 100% for patients of China and 95.9% for patients of Taiwan (p = 0.836).

Conclusions

OAGB in situ is a safe and effective bariatric/metabolic surgery. With proper training and proctorship, these results are reproduceable in a new bariatric/metabolic surgical center in China.

Graphical abstract

What Is the Efficacy of Short Length of Biliopancreatic Limb in One-Anastomosis Gastric Bypass? A Systematic Review and Meta-analysis of Short-Term Results

OBJECTIVE

To systematically review the efficacy of short length of biliopancreatic limb (BPL) in laparoscopic one anastomosis gastric bypass (OAGB).

METHODS

By thoroughly investigating in PubMed, Embase, and the Cochrane Library, each research containing the comparison between short BPL and 200-cm BPL was included, inception in July 2021. The research followed the guidance of Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) recommendations.

RESULT

A total of 1288 patients were included for meta-analysis. Results showed that in the short term, compared with 200-cm BPL, percentage excess weight loss (%EWL) did not show significant reduction (p = 0.91), neither did the incidence of vitamin D deficiency (p = 0.87) nor hypoalbuminemia (p = 0.06), while percentage total weight loss (%TWL) was significantly higher in the 200-cm BPL group (p = 0.0005). At 1, 2, and 8 years postoperatively, patients with short BPL still obtained significantly reduced body mass index (BMI).

CONCLUSION

Short BPL shows significant effect of weight loss; however, it seems no significantly lower rates of adverse events in the short term are found. More research with randomized controlled design is encouraged to further address the incidence of adverse events in the long term.