Short- and Mid-term Outcomes of 527 One Anastomosis Gastric Bypass/Mini-Gastric Bypass (OAGB/MGB) Operations: Retrospective Study

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

BACKGROUND

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.

METHODS AND PATIENTS

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).

RESULTS

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.

CONCLUSION

The results of this study indicate that OAGB has acceptable long-term effects on weight loss and the remission or improvement of obesity-related medical conditions.

Long-Term Follow-Up After Bariatric Surgery: Key to Successful Outcomes in Obesity Management

Background/Objectives: Bariatric surgery (BS) is considered one of the most effective interventions for the treatment of obesity. To achieve optimal long-term results, continuous follow-up (FU) within a multidisciplinary treatment team is essential to ensure patient compliance and maximize the benefits of BS. However, many patients find it difficult to maintain regular FU, which can affect the quality of care and lead to postoperative complications. This review aims to highlight factors that may hinder compliance with FU after BS, examine potential causes and consequences of inadequate FU, and identify strategies to improve patient participation in long-term FU. Methods: The literature search was conducted between October 2023 and June 2024 in Medline (PubMed) and the Cochrane Library datasets. Studies were selected for their relevance to adherence to FU, multidisciplinary approaches, and long-term bariatric outcomes. Results: The pre- and postoperative period is critical for educating patients and healthcare team members about the importance of FU, addressing potential barriers (e.g., logistical, psychological, and social challenges), and highlighting the risk of relapse to obesity after surgery. The lack of a standardized FU protocol leads to differences between medical centers, further impacting patient adherence. Conclusions: Tailored and regularly updated strategies are essential to address individual patient needs and improve adherence to FU. Further research is needed to identify the specific factors that influence variability in long-term BS outcomes, highlighting the need for a patient-centered approach to obesity treatment.

The length of the biliopancreatic limb in one anastomosis gastric bypass

Introduction

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.

Methods

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.

Results

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.

Conclusion

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.

Decision-making Considerations in Revisional Bariatric Surgery

OBJECTIVE

With drastic variations in bariatric practices, consensus is lacking on an optimal approach for revisional bariatric surgeries.

MATERIALS AND METHODS

The authors reviewed and consolidated bariatric surgery literature to provide specific revision suggestions based on each index surgery, including adjustable gastric band (AGB), sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), biliopancreatic diversion with duodenal switch (BPD-DS), single anastomosis duodenal-ileal bypass with sleeve (SADI-S), one anastomosis gastric bypass (OAGB), and vertical banded gastroplasty (VBG).

RESULTS

AGB has the highest weight recurrence rate and can be converted to RYGB, SG, and BPD-DS. After index SG, common surgical options include a resleeve or RYGB. The RYGB roux limb can be distalized and pouch resized in context of reflux, and the entire anatomy can be revised into BPD-DS. Data analyzing revisional surgery after a single anastomosis duodenal-ileal bypass with sleeve was limited. In patients with one anastomosis gastric bypass and vertical banded gastroplasty anatomy, most revisions were the conversion to RYGB.

CONCLUSIONS

As revisional bariatric surgery becomes more common, the best approach depends on the patient's indication for surgery and preexisting anatomy.

Technical Variations and Considerations around OAGB in IFSO-APC and IFSO-MENAC Chapters, an Expert Survey

OBJECTIVE

This study aimed to evaluate the technical variations of one-anastomosis gastric bypass (OAGB) among IFSO-APC and MENAC experts.

BACKGROUND

The multitude of technical variations and patient selection challenges among metabolic and bariatric surgeons worldwide necessitates a heightened awareness of these issues. Understanding different perspectives and viewpoints can empower surgeons performing OAGB to adapt their techniques, leading to improved outcomes and reduced complications.

METHODS

The scientific team of IFSO-APC, consisting of skilled bariatric and metabolic surgeons specializing in OAGB, conducted a confidential online survey. The survey aimed to assess technical variations and considerations related to OAGB within the IFSO-APC and IFSO-MENAC chapters. A total of 85 OAGB experts participated in the survey, providing their responses through a 35-question online format. The survey took place from January 1, 2024, to February 15, 2024.

RESULTS

Most experts do not perform OAGB for children and adolescents younger than 18 years. Most experts create the gastric pouch over a 36-40-F bougie and prefer to create a gastrojejunostomy, at the posterior wall of the gastric pouch. An anti-reflux suture during OAGB is performed in all patients by 51.8% of experts. Most experts set a common limb length of > 4 m in revisional and conversional OAGBs to prevent nutritional complications.

CONCLUSION

The ongoing debate among metabolic and bariatric surgeons regarding the technical variations and patient selection in OAGB remains a significant point of discussion. This survey demonstrated the variations in technical aspects and patient selection for OAGB among MBS surgeons in the IFSO-APC and IFSO-MENAC chapters. Standardizing the OAGB technique is crucial to ensure optimal safety and efficacy in this procedure.

Primary versus Revisional One Anastomosis Gastric Bypass: Outcomes of Patients with at Least 8-Year Follow-Up

INTRODUCTION

One anastomosis gastric bypass (OAGB) prevalence is increasing worldwide and shows good mid- to long-term results. Data on long-term outcomes of revisional OAGB (rOAGB) is limited. This study's objective was to evaluate the long-term outcomes of patients undergoing primary OAGB (pOAGB) and rOAGB.

METHODS

A retrospective analysis of a prospectively maintained patient registry at a single-tertiary center. Patients undergoing OAGB from January 2015 to May 2016 were included and grouped into pOAGB and rOAGB.

RESULTS

There were 424 patients, of which 363 underwent pOAGB, and 61 underwent rOAGB. Baseline characteristics were insignificantly different between groups except for the type 2 diabetes (T2D) rate which was higher in pOAGB (26% vs. 11.5%, p = 0.01). The mean follow-up time was 98.5 ± 3.9 months, and long-term follow-up data were available for 52.5% of patients. The mean total weight loss (TWL) was higher in the pOAGB group (31.3 ± 14 vs. 24.1 ± 17.6, p = 0.006); however, TWL was comparable when relating to the weight at primary surgery for rOAGB. The rate of T2D and hypertension resolution was 79% and 72.7% with no difference between groups. Thirteen patients (5.9%) underwent OAGB revision during follow-up, with no difference between groups. Two deaths occurred during follow-up, both non-related to OAGB.

CONCLUSION

OAGB is effective as a primary and as a revisional procedure for severe obesity with good long-term results in terms of weight loss and resolution of associated diseases. In addition, the revisional surgery rates and chronic complications are acceptable. Further large prospective studies are required to clarify these data.

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.

Variation in HbA1c in Patients with Obesity and type 2 Diabetes Mellitus 12 months after Laparoscopic One-Anastomosis Gastric Bypass and Laparoscopic Roux-en-Y Gastric Bypass: a Retrospective Matched Cohort Study

BACKGROUND

Glycemic control is an important goal of bariatric surgery in patients with type 2 diabetes mellitus (T2DM) and obesity. The laparoscopic one-anastomosis gastric bypass (OAGB) has potential metabolic benefits over the laparoscopic Roux-en-Y gastric bypass (RYGB). Aim of this study is to examine whether RYGB or OAGB grants better glycemic control 12 months post-surgery.

METHODS

For this retrospective cohort study, patients with T2DM and obesity, who underwent primary OAGB between 2008 and 2017 were reviewed. For each OAGB patient, three primary RYGB patients were matched for age, gender and body mass index (BMI). Glycemic control was expressed by the glycated hemoglobin (HbA1c), which was measured pre- and 12 months post-operatively. Weight loss was reported in percentage total weight loss (%TWL).

RESULTS

A total of 152 patients, of whom 38 had OAGB and 114 RYGB, were included. Mean (standard deviation (SD)) HbA1c was 7.49 (1.51)% in the OAGB group and 7.56(1.23)% in the RYGB group at baseline. Twelve months after surgery the mean (SD) HbA1c dropped to 5.73 (0.71)% after OAGB and 6.09 (0.76)% after RYGB (adjusted p = 0.011). The mean (SD) BMI was reduced from 42.5(6.3) kg/m2 to 29.6(4.7) kg/m2 after OAGB and 42.3(5.8) kg/m2 to 29.9 (4.5) kg/m2 after RYGB; reflecting 30.3 (6.8) %TWL post-OAGB and 29.0 (7.3) %TWL post-RYGB (p = 0.34).

CONCLUSION

This study indicates that OAGB leads to lower HbA1c one year after surgery compared to RYGB, without a difference in weight loss. Prospective (randomized) studies are needed to ascertain the most optimal metabolic treatment for patients with obesity and T2DM.

OAGB Bowel Function in Patients With up to 5 Years Follow-Up: Updated Outcomes

OBJECTIVE

One-anastomosis gastric bypass (OAGB) is considered an effective technique in weight reduction and remission of comorbidities. However, in common with many bariatric and metabolic/bariatric procedures, gastrointestinal side effects are frequently reported, but clinical experience varies. The objective of this study was to analyze the bowel function of patients who undergo OAGB looking at 5-year postoperative outcomes.

METHOD

This study is cross-sectional, descriptive and analytical, developed with individuals undergoing OAGB (n = 208) in yhe period between 2015 and 2020. The time periods evaluated were 1 to 6 months (T1), 6 to 12 months (T2), and 1 to 5 years (T3). Data analysis was performed using SPSS v.28.0, considering a significance level p ≤ 0.05.

RESULTS

114 participants (54.8%), 79.8% women, mean age 47.0 ± 12.6 years, and BMI 40.1 ± 5.6 kg/m2, 51.9% dyslipidemia, 43.6% arterial hypertension, and 19.1% diabetes mellitus. The T1 group had more severe symptoms/nausea than the T2 group. The T2 group had a significantly lower defecation frequency than the T1 and T3 groups. As for the occurrence of diarrhea, associations were not found in the considered groups. The T3 group had a greater severity of constipation associated with greater difficulty in consuming red meat, white meat, rice, vegetables, and salads.

CONCLUSIONS

Gastrointestinal symptoms are prevalent in the first postoperative months. However, diarrhea was not common. The patient selection policy and surgical technique were decisive in this result. Constipation was prevalent in patients between 1 and 5 postoperative years. It was also prevalent in those who had food intolerance, which from a nutritional point of view is an adverse factor for optimal bowel function.

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.

One Anastomosis Gastric Bypass in 6722 Patients: Early Outcomes from a Private Hospital Registry

BACKGROUND

One-anastomosis gastric bypass (OAGB) is an emerging metabolic bariatric surgery (MBS) type used in both primary OAGB (pOAGB) and revisional OAGB (rOAGB). We studied ≤30-day outcomes of pOAGB and rOAGB and identified predictors of early complications.

METHODS

Electronic medical records of all OAGBs performed between January 2017 and December 2021 at a high-volume bariatric clinic in Israel comprising four hospital centers were scanned retrospectively using specialized data software (MDClone software, version 6.1). Data gathered were patients' characteristics, surgical procedure, and ≤30-day complications with Clavien-Dindo Classification (CDC). Multivariate logistic regression analyses were used to identify factors related to early complications of pOAGB and rOAGB.

RESULTS

A total of 6722 patients underwent a pOAGB (n = 5088, 75.7%) or rOAGB (n = 1634, 24.3%) procedure at our institution. Preoperative mean age and body mass index (BMI) were 40.6 ± 11.5 years and 41.2 ± 4.6 kg/m2, respectively. Early complications occurred in 258 (3.8%) patients (176 pOAGB and 82 rOAGB) and included mainly bleeding (n = 133, 2.0%), leaks (n = 31, 0.5%), and obstruction/strictures (n = 19, 0.3%). CDC complications for grades 1-2 and grades 3a--5 were 1.5% and 1.6%, respectively. The overall mortality rate was 0.03% (n = 2). Age, operative time ≥3 h, and any additional concomitant procedure were independent predictors of early complications following pOAGB, while a diagnosis of diabetes mellitus and operative time ≥3 h were independent predictors of early complications following rOAGB.

CONCLUSIONS

OAGB was found to be a safe primary and revisional MBS procedure in the ≤30-postoperative day term. The most common complications were gastrointestinal bleeding, leaks, and obstruction/stricture.

The effect of Roux-en-Y gastric bypass compared with omega-loop gastric bypass on weight loss, perioperative surgical events, and comorbidities

BACKGROUND

In comparison to conservative therapy, bariatric surgery has shown many reasonable results. The current study investigates whether Omega-loop-gastric-bypass (OAGB) or Roux-en-Y gastric-bypass (RYGB) improves weight loss, comorbidities, and perioperative complications.

METHODS

The study included 28,683 patients after RYGB and OAGB. Outcome criteria were perioperative morbidity, perioperative complications, and remission of comorbidities after one year of follow-up.

RESULTS

Of them 14,253 patients had completed a one-year follow-up (13,483 patients by RYGB and 770 by OAGB). BMI reduction was a significant difference in favor of OAGB (17.5±5.6 kg/m² for OAGB vs. 15.2±5.0 for RYGB; P<0.001). The %EWL was not significantly different between the two groups (P=0.073). There was also no significant difference in perioperative complications between the two groups (overall P>5%). Significant differences in favor of OAGB were observed in remission of insulin-dependent diabetes mellitus (IDDM) (P<0.001), and sleep apnea (P=0.002). Remission of reflux was more observed in RYGB than OAGB (P<0.001). Operating time was significantly higher in RYGB than OAGB (P<0.001).

CONCLUSIONS

Compared with RYGB, OAGB showed significant advantages in many respects. In particular, remission of comorbidities was significantly better after OAGB than in patients after RYGB during the one-year follow-up period. Nevertheless, many other factors such as medical history, long-term expected goals of bariatric surgery, and preexisting comorbidities should be taken into account when determining indications between the two procedures. Further studies with longer follow-up periods should be conducted to determine the efficacy of the two methods more accurately.

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.

Outcomes of 325 one anastomosis gastric bypass operations: an Australian case series

BACKGROUND

The One Anastomosis Gastric Bypass (OAGB) is a relatively novel procedure. Studies have demonstrated that it is at least as effective as other bariatric procedures but with fewer major complications and shorter operating time, yet OAGB is performed less partially due to a paucity of supportive evidence. We report the outcomes of a prospectively maintained database of patients undergoing laparoscopic OAGB.

METHODS

All OAGB procedures performed by two surgeons across two hospitals from 2016 to 2019 were recorded in a prospectively maintained database. Patients with at least 1 year of follow up were included in this study and missing data was obtained from patient records. The primary outcome was percentage excess weight loss (EWL). The secondary outcome was surgical complication rate.

RESULTS

Three hundred and twenty-five patients with a mean pre-operative body mass index of 43.3 kg/m² were included. The majority (85.2%) had a biliopancreatic limb length of 150 cm. The median EWL was 74.2% and 79.4% of patients achieved at least 50% EWL. There were no deaths, the overall re-operation rate was 4.9% and 1.9% of patients developed stomal ulcers. Seven patients went on to have a Roux-en-Y conversion predominantly for symptomatic reflux.

CONCLUSION

OAGB leads to excellent weight loss and is at least as safe as more commonly performed procedures, it may be a suitable treatment for a greater number of patients than it is being offered to at present.

Effect of Biliopancreatic Limb Length on Weight Loss, Postoperative Complications, and Remission of Comorbidities in One Anastomosis Gastric Bypass: a Systematic Review and Meta-analysis

Aimed to evaluate the effects of biliopancreatic limb (BPL) length on weight loss, postoperative complications, and remission of comorbidities in OAGB.. An extensive search was conducted in PubMed, Scopus, EMBASE, and Google Scholar databases to find related OAGB articles. Both BPL length < 200 cm (by - 17.79, 95% CI - 19.23, - 16.34) and BPL length ≥ 200 cm (by - 14.93, 95% CI - 15.66, - 14.20) significantly decreased BMI. Regarding the effect of BPL length on comorbidities and postoperative complications, it was shown that BPL length < 200 cm is safer and more effective. Therefore, standardization of BPL length < 200 cm is suggested. Bypassing ≥ 200 cm of the small bowel does not ameliorate weight loss or resolve comorbidities significantly, and it is related to more frequent postoperative complications and nutritional deficiencies. Registration number in PROSPERO: PROSPERO 2021 CRD42021225499.

Conversion from one-anastomosis gastric bypass to Roux-en-Y gastric bypass: when and why-a single-center experience of all consecutive OAGB procedures

BACKGROUND

One-anastomosis gastric bypass (OAGB) is a well-established treatment method in patients with morbid obesity. Its long-term impact on de novo reflux, anastomotic complications, and malnutrition needs further evaluation. Roux-en-Y gastric bypass (RYGB) is a technically feasible procedure in revisional bariatric surgery. This study presents our institutional data on conversion from OAGB to RYGB.

OBJECTIVE

To determine the reasons for conversion, preoperative endoscopic findings, and feasibility of revisional bariatric surgery after OAGB.

SETTING

University hospital in Austria METHODS: Retrospective analysis of a prospectively fed database. All patients undergoing OAGB between January 2012 and December 2019 were included. Screening was carried out for all patients needing conversion to RYGB. Percent total weight loss, percent excess weight loss, time to conversion, postoperative complications, and reasons for conversion were assessed.

RESULTS

Eighty-two of 1,025 patients who underwent OAGB were converted laparoscopically to RYGB. Seven patients were converted early because of anastomotic/gastric tube leakage. Median time to late conversion was 29.1 ± 24.3 months, mean percent excess weight loss was 86.6% ± 33.1% and percent total weight loss was 35.1% ± 13.5%. Forty-two patients were converted because of reflux, 11 because of persistent marginal ulcers, 10 because of anastomotic stenosis, 9 because of malnutrition, and 3 because of weight regain. Seven patients showed Barrett's metaplasia in biopsies at the gastroesophageal junction before conversion.

CONCLUSION

Laparoscopic conversion from OAGB to RYGB is technically feasible with a moderate rate of postoperative complications. Severe (bile) reflux is a serious long-term complication after OAGB, with 4.1% of patients needing conversion to RYGB. Endoscopy after OAGB in patients showing clinical symptoms of gastroesophageal reflux disease is strongly advised to detect underlying pathologic changes.

Areas of Non-Consensus Around One Anastomosis/Mini Gastric Bypass (OAGB/MGB): A Narrative Review

PURPOSE

One anastomosis/mini gastric bypass (OAGB/MGB) is now an established bariatric and metabolic surgical procedure with good outcomes. Despite two recent consensus statements around OAGB/MGB, there are some issues which are not accepted as consensus and need more long-term data and research.

MATERIAL AND METHODS

After identifying the topic of non-consensus from the two recent OAGB/MGB consensuses, PubMed, Scopus, and Cochrane were searched for articles published by November 2020.

RESULTS

In this study, we evaluated these non-consensus topics around OAGB/MGB and all related articles on these topics were assessed by authors to have an argument on these items.

CONCLUSION

There is enough evidence to include OAGB/MGB as an accepted standard bariatric and metabolic surgical procedure. However, long-term data and more research are needed to have a consensus in all aspects including these non-consensus topics.

IFSO Update Position Statement on One Anastomosis Gastric Bypass (OAGB)

The International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) issued a position statement on the role of one anastomosis gastric bypass (OAGB) in the field of bariatric/metabolic surgery in 2018 De Luca et al. (Obes Surg. 28(5):1188-206, 2018). This position statement was issued by the IFSO OAGB task force and approved by the IFSO Scientific Committee and IFSO Executive Board. In 2018, the OAGB task force recognized the necessity to update the position statement in the following 2 years since additional high-quality data could emerge. The updated IFSO position statement on OAGB was issued also in response to inquiries to the IFSO by society members, universities, hospitals, physicians, insurances, patients, policy makers, and media. The IFSO position statement on OAGB has been reviewed within 2 years according to the availability of additional scientific evidence. The recommendation of the statement is derived from peer-reviewed scientific literature and available knowledge. The IFSO update position statement on OAGB will again be reviewed in 2 years provided additional high-quality studies emerge.

Prevention and treatment of nutritional complications after bariatric surgery

Obesity and the corresponding burden of related diseases is a major public health issue worldwide that is reaching pandemic proportions. Bariatric surgery is the only intervention that has been shown to result in substantial and lasting weight loss, and a decrease in overall mortality for patients with severe obesity. Consequently, the population of patients having undergone this procedure is increasing. Multifactorial weight-dependent and independent mechanisms underlying metabolic diseases could also drive preventable, but potentially life-threatening, long-term nutritional complications. However, given post-bariatric patients are prone to functional gastrointestinal symptoms and substantial weight loss, nutritional complications might be challenging. This Review is focused on the prevention and treatment of nutritional complications after bariatric surgery in the clinical setting.

Changes in Anthropometric Measures, Nutritional Indices and Gastrointestinal Symptoms Following One Anastomosis Gastric Bypass (OAGB) Compared with Roux-en-y Gastric Bypass (RYGB)

Purpose

Bariatric surgery is an effective treatment for obesity with new procedures emerging. However, despite comparable weight loss and improvements in metabolic outcomes, research on nutritional and gastrointestinal symptoms remains limited. Here we compare clinical data on weight, nutritional disorders and gastrointestinal symptoms of patients before and following one anastomosis gastric bypass (OAGB) and Roux-en-Y gastric Bypass (RYGB).

Materials and Methods

In this retrospective study, data on anthropometry, nutritional indices, dietary intake and gastrointestinal symptoms were retrieved in cohorts of patients up to 2 years following OAGB and RYGB.

Results

Seventy-three patients had either a RYGB (28) or an OAGB (45), with 71% seeking these as a revisional procedure. Significant and higher weight loss was observed in the OAGB cohort at 1 year (%TWL 33.0 ± 8.5 vs. 26.6 ± 12.4), albeit comparable at 2 years postoperatively (%TWL 29.0 ± 11.1 vs. 34.1 ± 11.2). Disorders such as vitamin D, active B12, folate, homocystein (Hcy) and hyperparathyroidism were present following both surgeries. Levels of vitamin D, ferritin and total protein significantly worsened over time. Gastrointestinal symptoms of diarrhoea, steatorrhoea and reflux were higher in the OAGB cohort while the RYGB cohort reported more dumping syndrome (DS).

Conclusion

Significant and similar weight loss results are seen following both OAGB and RYGB. Nutritional disorders were common in both cohorts and increased over time. However, the OAGB patients reported more gastrointestinal side effects, which may contribute to poor quality of life and nutritional consequences. Prospective and longer-term studies investigating the nutritional and gastrointestinal health of patients undergoing OAGB is recommended.

Effect of one-anastomosis gastric bypass on cardiovascular risk factors in patients with vitamin D deficiency and morbid obesity: A secondary analysis

BACKGROUND AND AIMS

Bariatric patients often suffer from vitamin D (VD) deficiency, and both, morbid obesity and VD deficiency, are related to an adverse effect on cardiovascular disease (CVD) risk. Therefore, we assessed the change of known CVD risk factors and its associations during the first 12 months following one-anastomosis gastric bypass (OAGB).

METHODS AND RESULTS

In this secondary analysis, CVD risk factors, medical history and anthropometric data were assessed in fifty VD deficient (25-hydroxy-vitamin D (25(OH)D) <75 nmol/l) patients, recruited for a randomized controlled trial of VD supplementation. Based on previous results regarding bone-mass loss and the association between VD and CVD risk, the study population was divided into patients with 25(OH)D ≥50 nmol/l (adequate VD group; AVD) and into those <50 nmol/l (inadequate VD group; IVD) at 6 and 12 months (T6/12) postoperatively. In the whole cohort, substantial remission rates for hypertension (38%), diabetes (30%), and dyslipidaemia (41%) and a significant reduction in CVD risk factors were observed at T12. Changes of insulin resistance markers were associated with changes of total body fat mass (TBF%), 25(OH)D, and ferritin. Moreover, significant differences in insulin resistance markers between AVD and IVD became evident at T12.

CONCLUSION

These findings show that OAGB leads to a significant reduction in CVD risk factors and amelioration of insulin resistance markers, which might be connected to reduced TBF%, change in 25(OH)D and ferritin levels, as an indicator for subclinical inflammation, and an adequate VD status. REGISTERED AT CLINICALTRIALS.GOV: (Identifier: NCT02092376) and EudraCT (Identifier: 2013-003546-16).

Revisional surgery after one anastomosis/mini gastric bypass: A narrative review

One anastomosis gastric bypass (OAGB)/mini gastric bypass is now considered to be a safe and efficient method for morbidly obese patients but has complications and adverse events such as other surgical procedures. The present paper outlines the need for and the nature of revisional surgery in the long-term following OAGB in accordance with the preferred reporting items for systematic reviews and meta-analysis guidelines. A literature search was carried out in PubMed. All articles on OAGB for which the authors described a patient needing revisional surgery in the long term after OAGB were examined.

IFSO (International Federation for Surgery of Obesity and Metabolic Disorders) Consensus Conference Statement on One-Anastomosis Gastric Bypass (OAGB-MGB): Results of a Modified Delphi Study

BACKGROUND

One-anastomosis gastric bypass (OAGB-MGB) is currently the third performed primary bariatric surgical procedure worldwide. However, the procedure is hampered by numerous controversies and there is considerable variability in surgical technique, patient selection, and pre- and postoperative care among the surgeons performing this procedure. This paper reports the results of a modified Delphi consensus study organized by the International Federation for Surgery of Obesity and Metabolic Disorders (IFSO).

METHODS

Fifty-two internationally recognized bariatric experts from 28 countries convened for voting on 90 consensus statements over two rounds to identify those on which consensus could be reached. Inter-voter agreement of ≥ 70% was considered consensus, with voting participation ≥ 80% considered a robust vote.

RESULTS

At least 70% consensus was achieved for 65 of the 90 questions (72.2% of the items), 61 during the first round of voting and an additional four in the second round. Where consensus was reached on a binary agree/disagree or yes/no item, there was agreement with the statement presented in 53 of 56 instances (94.6%). Where consensus was reached on a statement where options favorable versus unfavorable to OAGB-MGB were provided, including statements in which OAGB-MGB was compared to another procedure, the response option favorable to OAGB-MGB was selected in 13 of 23 instances (56.5%).

CONCLUSION

Although there is general agreement that the OAGB-MGB is an effective and usually safe option for the management of patients with obesity or severe obesity, numerous areas of non-consensus remain in its use. Further empirical data are needed.

Retrospective cohort study of 925 OAGB procedures. The UK MGB/OAGB collaborative group

BACKGROUND

Mini-One Anastomosis Gastric Bypass is a new operation that provides comparable outcomes to the common bariatric procedures. Revisional surgery is still needed after a number of MGB-OAGB procedures. The aim of this study is to report the causes and management of these revisions.

METHODS

From 2010 to 2018, 925 MGB-OAGB operations were performed at 7 bariatric units across the United Kingdom and included in this retrospective cohort study. The data was retrospectively collected and analysed. The primary end point was the identification of the causes and management of revisions. Follow up ranged from 6 months to 3 years.

RESULTS

Twenty-two patients [2.3%] required revisional surgery after MGB-OAGB. Five patients [0.5%] developed severe diarrhoea managed by shortening the bilio-pancreatic limb to 150 cm. Four patients [0.4%] developed afferent loop syndrome and bile reflux was reported in another 3 [0.3%] cases; all were managed by either conversion to Roux en Y Gastric Bypass or a Braun anastomosis. Postoperative bleeding was controlled laparoscopically in 3 patients [0.3%]. Liver decompensation that was reported in 2 patients [0.2%] was treated by shortening the BPL in one patient and a reversal to normal anatomy in another. The liver failure resolved in both patients. Other indications for revision included two gastro-jejunal stenosis [0.2%], one perforated ulcer [0.1%], one patient [0.1%] with excessive weight loss and one case [0.1%] of protein malnutrition. None of the 22 patients undergoing revisional surgery after MGB-OAGB died. Lost to follow up rate was 0.2%.

CONCLUSION

Complications requiring revisional surgery after MGB-OAGB are uncommon [2.3%] and the majority can be managed by bilio-pancreatic limb shortening, the addition of a Braun side-to-side anastomosis or conversion to RYGB. Bilio-pancreatic limb length of 200 cm or more resulted in serious complications of liver failure, protein malnutrition, excessive weight loss and diarrhoea.

Nutritional status following One Anastomosis Gastric Bypass

BACKGROUND & AIMS

One Anastomosis Gastric Bypass (OAGB) has been accepted as an effective treatment for morbid obesity. However, data are scarce regarding nutritional implications of this procedure. Thus, our aim was to describe the health and nutritional status 12-20 months following OAGB surgery.

METHODS

A prospective cohort study on patients who underwent OAGB surgery from January 2016 to May 2017 in a large, multi-disciplinary, bariatric clinic. Pre-surgery data including demographic details, anthropometrics, co-morbidities, blood tests and lifestyle habits were obtained from the patients' medical records. Follow-up evaluations were performed 12-20 months post-surgery and data collected included anthropometrics, blood tests, eating and lifestyle parameters, adherence to follow-up regime and gastrointestinal (GI) related side effects. In addition, patients were asked to rate their overall state of health (OSH) from 0 to 100 using a visual analogue scale (VAS).

RESULTS

Eighty-six OAGB patients (72.1% women) were tested 14.7 ± 2.0 months post-operatively. Their mean age and BMI preoperatively were 46.1 ± 11.4 years and 42.0 ± 4.9 kg/m², respectively. The mean % excess weight loss at 12-20 months postoperatively was 88.4 ± 19.3%. Lipid and glucose profiles were significantly improved at 12-20 months postoperatively compared to baseline (P < 0.001 for all). Relatively high proportions of nutritional deficiencies were found pre-operatively and postoperatively for iron (33.9% vs. 23.7%, P = 0.238), folate (30.9% vs. 11.8%, P = 0.004), vitamin D (56.6% vs. 17.0%, P < 0.001) and hemoglobin (16.7% vs. 42.9%, P < 0.001). Postoperatively, most participants reported taking multivitamin, calcium, vitamin D and vitamin B12 supplementation (≥62.8%), having participated in at least 6 meetings with a dietitian (51.8%) and presently doing physical activity (69.4%). The mean postoperative OSH VAS score was 88.2 ± 12.3, but most participants reported on flatulence (67.4%) and some reported on diarrhea (25.6%) as GI side effects of the surgery.

CONCLUSIONS

Substantial improvements in health and anthropometric parameters are found in the short-term follow-up after OAGB, with a satisfactory reported quality of life and adherence to recommendations. However, a high prevalence of some GI side effects, nutritional deficiencies and specially anemia is a matter of concern.