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

The Effects of One Anastomosis Gastric Bypass Surgery on the Gastrointestinal Tract

One anastomosis gastric bypass (OAGB) is an emerging bariatric procedure, yet data on its effect on the gastrointestinal tract are lacking. This study sought to evaluate the incidence of small-intestinal bacterial overgrowth (SIBO) following OAGB; explore its effect on nutritional, gastrointestinal, and weight outcomes; and assess post-OABG occurrence of pancreatic exocrine insufficiency (PEI) and altered gut microbiota composition. A prospective pilot cohort study of patients who underwent primary-OAGB surgery is here reported. The pre-surgical and 6-months-post-surgery measurements included anthropometrics, glucose breath-tests, biochemical tests, gastrointestinal symptoms, quality-of-life, dietary intake, and fecal sample collection. Thirty-two patients (50% females, 44.5 ± 12.3 years) participated in this study, and 29 attended the 6-month follow-up visit. The mean excess weight loss at 6 months post-OAGB was 67.8 ± 21.2%. The glucose breath-test was negative in all pre-surgery and positive in 37.0% at 6 months (p = 0.004). Positive glucose breath-test was associated with lower reported dietary intake and folate levels and higher vitamin A deficiency rates (p ≤ 0.036). Fecal elastase-1 test (FE1) was negative for all pre-surgery and positive in 26.1% at 6 months (p = 0.500). Both alpha and beta diversity decreased at 6 months post-surgery compared to pre-surgery (p ≤ 0.026). Relatively high incidences of SIBO and PEI were observed at 6 months post-OAGB, which may explain some gastrointestinal symptoms and nutritional deficiencies.

Revisional Surgery After One Anastomosis/Minigastric Bypass: an Italian Multi-institutional Survey

BACKGROUND

Efficacy and safety of OAGB/MGB (one anastomosis/mini gastric bypass) have been well documented both as primary and as revisional procedures. However, even after OAGB/MGB, revisional surgery is unavoidable in patients with surgical complications or insufficient weight loss.

METHODS

A questionnaire asking for the total number and demographics of primary and revisional OAGB/MGBs performed between January 2006 and July 2020 was e-mailed to all S.I.C. OB centres of excellence (annual caseload > 100; 5-year follow-up > 50%). Each bariatric centre was asked to provide gender, age, preoperative body mass index (BMI) and obesity-related comorbidities, previous history of abdominal or bariatric surgery, indication for surgical revision of OAGB/MGB, type of revisional procedure, pre- and post-revisional BMI, peri- and post-operative complications, last follow-up (FU).

RESULTS

Twenty-three bariatric centres (54.8%) responded to our survey reporting a total number of 8676 primary OAGB/MGBS and a follow-up of 62.42 ± 52.22 months. A total of 181 (2.08%) patients underwent revisional surgery: 82 (0.94%) were suffering from intractable DGER (duodeno-gastric-esophageal reflux), 42 (0.48%) were reoperated for weight regain, 16 (0.18%) had excessive weight loss and malnutrition, 12 (0.13%) had a marginal ulcer perforation, 10 (0.11%) had a gastro-gastric fistula, 20 (0.23%) had other causes of revision. Roux-en-Y gastric bypass (RYGB) was the most performed revisional procedure (109; 54%), followed by bilio-pancreatic limb elongation (19; 9.4%) and normal anatomy restoration (19; 9.4%).

CONCLUSIONS

Our findings demonstrate that there is acceptable revisional rate after OAGB/MGB and conversion to RYGB represents the most frequent choice.

Laparoscopic Banded One Anastomosis Gastric Bypass: A Single-Center Series

INTRODUCTION

Laparoscopic one anastomosis gastric bypass (LOAGB) is a relatively new procedure for the treatment of morbid obesity and related comorbidities. On average, this procedure results in good postoperative weight loss with a low complication rate. Recent publications suggest that dumping syndrome and weight regain might be reduced by placing a silicone ring over the gastric pouch during the procedure, so called laparoscopic banded one anastomosis gastric bypass (LBOAGB).

METHODS

86 patients undergoing LBOAGB between 2018 and 2020 were enrolled in this retrospective study. Hospital records were used to assess weight loss, comorbidity resolution, and any complications either in the short or medium term.

RESULTS

54 Female and 32 male patients were included with a mean age of 43 years (25-64), preoperative body mass index of 42 kg/m² (35-49), and preoperative weight of 114 kg (86-162). Thirty-four patients presented with type 2 diabetes (39.5%), 42 patients (49%) diagnosed with hypertension, 24 presented with OSAS (28%), and 21 (24%) hypercholesterolaemia patients were included. In total, 36 patients were diagnosed with multiple comorbidities. The operative data showed an average operative time of 48 minutes with 3.4% of patients suffering from early (minor) complications and 2.3% with a late (minor) complication. One patient required reoperation due to intra-abdominal bleeding. The median length of hospital stay was 2.5 days. Median follow-up was 18 months (5-36). In that period, no patient required ring removal or conversion to Roux-en-Y gastric bypass surgery. Food intolerance/vomiting was present in 1 patient (1.1%), bile reflux was present in 1 patient (1.1%), and no stomal ulcers were observed. Mean % excess weight loss at 12 and 24 months was 72% and 80%, respectively. Fifty-two out of 86 patients (60%) had a complete resolution of comorbidities. A CONUT score >2 (mild malnutrition) was found in 40% of patients, while a CONUT score 0-1 was found in 60% of patients.

CONCLUSION

LBOAGB shows promising results in terms of safety and efficacy in the short term. Further prospective studies will be required to evaluate the consistency of the results in the long term.

Quality of Life After Bariatric Surgery-a Systematic Review with Bayesian Network Meta-analysis

OBJECTIVE

Comprehensive analysis and comparison of HRQoL following different bariatric interventions through systematic review with network meta-analysis.

BACKGROUND

Different types of bariatric surgeries have been developed throughout the years. Apart from weight loss and comorbidities remission, improvement of health-related quality of life (HRQoL) is an important outcome of metabolic surgery.

METHODS

MEDLINE, EMBASE, and Scopus databases have been searched up to April 2020. Inclusion criteria to the analysis were (1) study with at least 2 arms comparing bariatric surgeries; (2) reporting of HRQoL with a validated tool; (3) follow-up period of 1, 2, 3, or 5 years. Network meta-analysis was conducted using Bayesian statistics. The primary outcome was HRQoL.

RESULTS

Forty-seven studies were included in the analysis involving 26,629 patients and 11 different surgeries such as sleeve gastrectomy (LSG), gastric bypass (LRYGB), one anastomosis gastric bypass (OAGB), and other. At 1 year, there was significant difference in HRQoL in favor of LSG, LRYGB, and OAG compared with lifestyle intervention (SMD: 0.44; 95% CrI 0.2 to 0.68 for LSG, SMD: 0.56; 95% CrI 0.31 to 0.8 for LRYGB; and SMD: 0.43; 95% CrI 0.06 to 0.8 for OAGB). At 5 years, LSG, LRYGB, and OAGB showed better HRQoL compared to control (SMD: 0.92; 95% CrI 0.58 to 1.26, SMD: 1.27; 95% CrI 0.94 to 1.61, and SMD: 1.01; 95% CrI 0.63 to 1.4, respectively).

CONCLUSIONS

LSG and LRYGB may lead to better HRQoL across most follow-up time points. Long-term analysis shows that bariatric intervention results in better HRQoL than non-surgical interventions.

Comparative Effectiveness of Bariatric Surgeries in Patients with Type 2 Diabetes Mellitus and BMI ≥ 25 kg/m2: a Systematic Review and Network Meta-Analysis

PURPOSE

In patients with type 2 diabetes mellitus (T2DM), bariatric surgery appears to be more effective than medical treatment (MT) at improving glycaemic control and decreasing cardiovascular risk. However, long-term effectiveness has not been systematically assessed using randomised controlled trials. In this study, we aimed to systematically assess randomised controlled trials, with at least 5 years of follow-up, on bariatric surgery in patients with T2DM and BMI ≥ 25 kg/m2, as well as to compare different bariatric procedures.

MATERIAL AND METHODS

PubMed, SCOPUS and Web of Science were searched. We performed a network meta-analysis to evaluate the comparative effectiveness of the different procedures and MT in terms of full T2DM remission, weight loss, complications and cardiometabolic biomarkers. The quality of evidence was assessed using the Cochrane Risk of Bias Tool and CINeMA.

RESULTS

We included 11 primary studies. Laparoscopic one-anastomosis gastric bypass (LOAGB) was found to be one of the most effective treatments for full remission of T2DM (I2 = 0, inconsistency p value = 0.9223). Biliopancreatic diversion without duodenal switch was found to be more effective than laparoscopic Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding regarding percent total cholesterol and low-density lipoprotein change. Regarding percent high-density lipoprotein and weight change, all analysed surgical treatments were shown to be more effective than MT. The confidence rating in our results was overall moderate, but most studies had high risk of performance and detection bias.

CONCLUSION

Bariatric surgery seems to be effective for T2DM remission. LOAGB appears to be a good option in this context, and a possible alternative to laparoscopic duodenal switch, but the included primary studies in our review are not sufficiently powered to establish a more definitive conclusion. More studies with longer follow-up times are needed to comprehensively assess bariatric surgery in T2DM.

Comparison of mid-term effectiveness and safety of one-anastomosis gastric bypass and sleeve gastrectomy in patients with super obesity (BMI ≥ 50 kg/m2)

PURPOSES

There is no consensus regarding the optimal bariatric procedure in patients with super obesity [body mass index (BMI) ≥ 50 kg/m²]. This study compared the outcomes of one-anastomosis gastric bypass (OAGB) with those of sleeve gastrectomy (SG) in these patients.

METHODS

This retrospective study was conducted based on the prospectively maintained data in a cohort of 557 patients with super obesity, who underwent either SG (n = 348) or OAGB with a 200-cm BPL (n = 154) or a 160-cm BPL (n = 55) by the same surgical team from March 2013 to 2017.

RESULTS

Patients undergoing OAGB had greater weight loss in comparison to those managed by SG during the first, second, and third years of follow-up. Comparing the OAGB and SG groups within 3 years after surgery, the total weight loss was 36.5 vs. 33.2% (P < 0.001) and the ΔBMI was 20.1 vs. 18.1 kg/m² (P < 0.001), respectively. The resolution of diabetes mellitus, hypertension and dyslipidemia were similar after the two procedures. The operative time and length of hospital stay were longer in the OAGB group, and incidence of complications, requiring either readmission or reoperation, was significantly higher after OAGB, in comparison to SG. There was no significant difference in the postoperative weight loss results, resolution of comorbidities, or the incidence of complications between the OAGB-160 and OAGB-200 groups, with the exception of protein-calorie malnutrition requiring revision surgery, which was exclusively observed in the OAGB-200 group.

CONCLUSION

Although OAGB provides superior mid-term weight loss, SG remains the first option for patients with super obesity, due to the safer surgical profile and comparable metabolic improvement.

A safety study of laparoscopic single-anastomosis duodeno-ileal bypass with gastric plication (SADI-GP) in the management of morbid obesity

Background

Bariatric surgery is more effective in the management of morbid obesity and related comorbidities than is conservative therapy. Pylorus-preserving single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-SG) is a modified duodenal switch technique. Gastric plication (GP) is an alternate to SG.

Methods

Morbidly obese (BMI of > 40, or > 35 in the presence of diabetes or prediabetes) patients were recruited and operated on to perform SADI with GP. Complications related to surgery were recorded to assess the feasibility of the procedure. Weight-loss outcomes were analysed to determine efficacy. Minnesota Multiphasic Personality Inventory 2 (MMPI-2) was recorded after 1 year of follow-up, and test scales were used to describe physiological phenomena.

Results

Seventeen middle-aged (mean: 40 years) patients were involved in our study; 15 of them were females. The mean duration of surgery was 205 min. There were no complications of conversion, death, bleeding, VTE or 30-day readmission to hospital. We did experience CD4a (pulmonary insufficiency due to chronic lung disease) and a CD3b (anastomosis leakage treated laparoscopically) complications. Vomiting occurred in three cases (CD1). Obesity-related comorbidities showed favourable resolution rates (77.8% for hypertension, 81.2% for dyslipidaemia, 100% for diabetes at the 1-year follow-up). Weight-loss outcomes were favourable (53.20 EWL%, and 35.58 TWL% at 1-year follow-up). Greater weight loss caused significantly higher levels of Depression (t(13.958) =  − 2.373; p = 0.00; p < 0.05) and Low Positive Emotions (t(13.301) =  − 2.954; p = 0.00; p < 0.05) and Introversion/Low Positive Emotionality (t(13.408) =  − 1.914; p = 0.02; p < 0.05) in MMPI-2 data.

Conclusion

According to our safety study, SADI-GP is a promising malabsorptive procedure, but a long-term high-volume case series or a randomised controlled trial is necessary to evaluate complication rates and weight-loss outcomes. Emotional dysregulation is common among bariatric surgery patients according to personality inventory data; therefore, psychological follow-up and psychotherapeutic support are necessary for weight-loss maintenance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00423-021-02276-9.

Network Meta-Analysis of Metabolic Surgery Procedures for the Treatment of Obesity and Diabetes

Background

Metabolic surgery is part of a well-established treatment intensification strategy for obesity and its related comorbidities including type 2 diabetes (T2DM). Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) and one-anastomosis gastric bypass (OAGB) are the most commonly performed metabolic surgeries worldwide, but comparative efficacy is uncertain. This study employed network meta-analysis to compare weight loss, T2DM remission and perioperative complications in adults between RYGB, SG and OAGB.

Methods

MEDLINE, EMBASE, trial registries were searched for randomised trials comparing RYGB, SG and OAGB. Study outcomes were excess weight loss (at 1, 2 and 3–5 years), trial-defined T2DM remission at any time point and perioperative complications.

Results

Twenty randomised controlled trials were included involving 1803 patients investigating the three metabolic surgical interventions. RYGB was the index for comparison. The excess weight loss (EWL) demonstrated minor differences at 1 and 2 years, but no differences between interventions at 3–5 years. T2DM remission was more likely to occur with either RYGB or OAGB when compared to SG. Perioperative complications were higher with RYGB when compared to either SG or OAGB. Two-way analysis of EWL and T2DM remission against the risk of perioperative complications demonstrated OAGB was the most positive on this assessment at all time points.

Conclusion

OAGB offers comparable metabolic control through weight loss and T2DM remission to RYGB and SG whilst minimising perioperative complications.

Registration number: CRD42020199779 (https:// www.crd.york.ac.uk/PROSPERO)

Graphical abstract

Acid Reflux Is Common in Patients With Gastroesophageal Reflux Disease After One-Anastomosis Gastric Bypass

INTRODUCTION

Patients with one-anastomosis gastric bypass (OAGB) can develop gastroesophageal reflux disease (GERD). The nature of this GERD (acid or biliary) remains unclear.

OBJECTIVE

To assess the nature of GERD via impedance pH testing in patients presenting with reflux post OAGB.

METHODS

Retrospective analysis of a prospectively collected database of 43 patients with OAGB backgrounds who developed postoperative GERD and were investigated with impedance pH monitoring between 2006 and 2019.

RESULTS

Mean age was 52.48 ± 9 years. Mean body mass index (BMI) prior to OAGB was 46.82 kg/m². None of these patients had clinical GERD before surgery. The median time interval between surgery and investigation with 24-h impedance pH monitoring was 64 (56) months. The mean BMI at the time of investigations was 32.67 ± 6.9 kg/m². The type of reflux was acid in 13 (30.2%), non-acid (biliary) in 12 (27.9%), and mixed (acid and biliary) in 5 (11.6%) patients. However, it remained not confirmed in 13 (30.2%). Median DeMeester score was 48.95 (27.67) in patients with acid, 2.8 (7.4) in patients with biliary, and 28.7 (5.6) in patients with mixed reflux. Median percent of time spent with pH < 4 was 9.65 (8) in patients with acid, 0.6 (1.75) in patients with biliary, and 7.7 (3.9) in patients with mixed reflux.

CONCLUSION

Acid reflux seems to be as common as bile reflux in patients presenting with GERD after OAGB. In case of revisional surgery for severe GERD post OAGB, 24-h impedance pH monitoring could be essential to determine the surgical procedure of choice.

Bariatric surgery for non-alcoholic fatty liver disease in individuals with obesity (Base-NAFLD): protocol of a prospective multicenter observational follow-up study

BACKGROUND

Bariatric surgery may be indicated in patients with nonalcoholic fatty liver disease (NAFLD) to achieve and maintain the degree of weight loss required to ensure therapeutic effects. However, bariatric surgery is still underrecognized in the treatment of NAFLD, including its inflammatory subtype, nonalcoholic steatohepatitis (NASH). Moreover, there is a lack of follow-up outcome data on different types of bariatric surgery in patients with NAFLD. This study aims to adequately assess the effect of bariatric surgery on NAFLD remission in obese patients.

METHODS

This prospective multicentre observational follow-up study will include 142 obese patients with NAFLD scheduled to undergo one of the following surgical procedures: sleeve gastrostomy, Roux-en-Y gastric bypass, and one anastomosis gastric bypass. The primary outcome is the complete remission rate of NAFLD one year postoperatively, which is defined by liver fat fraction < 5% on magnetic resonance imaging; the secondary outcomes includes (i) changes in NASH and liver fibrosis biopsy findings, (ii) changes in body weight and abdominal adipose weight, (iii) resolution of obesity-related comorbidities, and (iv) incidence of adverse events. A long-term follow-up related to this study will also be conducted.

DISCUSSION

This study will provide a necessary and preliminary foundation for the early identification and targeted treatment of patients with NAFLD who can be referred for bariatric surgery, as indicated for management of obesity and metabolic disease.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04366999. Registered 21 April 2020. ( https://clinicaltrials.gov/ct2/show/NCT04366999 ).

One-anastomosis gastric bypass (OAGB) in patients with BMI < 30 kg/m2 and diabetes mellitus type 2 (DM2)

INTRODUCTION

type-2 diabetes mellitus (DM2) is a major health problem, as it leads to increased morbidity and mortality. Metabolic surgery has shown good results in glycemic control; however, its use has not become popular.

OBJECTIVES

to evaluate DM2 remission, as well as changes in body mass index (BMI), in overweight diabetic patients after undergoing metabolic surgery.

METHODS

a retrospective review was carried out of all patients with DM2 and BMI between 25 and 29.9 kg/m2 who underwent laparoscopic one-anastomosis gastric bypass (OAGB) as metabolic procedure between 2016 and 2019.

RESULTS

a total of 15 patients were included with a mean age of 46.6 ± 11.25 years. Mean BMI was 28.41 ± 0.94 kg/m2. Average duration was 5.4 ± 2.79 years, and presurgical fasting glucose was 288.53 ± 65.22 mg/dL. Preoperative glycated hemoglobin (HbA1c) was 9.58 ± 1.66 %. Two years after surgery HbA1c was 5.21 ± 0.26 %. The remission rate of DM2 was 100 %. All patients maintained a normal BMI range.

CONCLUSIONS

OAGB is a valid alternative for complete DM2 remission no matter if it is not accompanied by some degree of obesity, since in this case the length of the biliopancreatic limb and common channel is modified to make a less malabsorptive procedure.

Long-Term Results of One Anastomosis Gastric Bypass: a Single Center Experience with a Minimum Follow-Up of 10 Years

PURPOSE

The purpose of this study was to evaluate the efficacy and safety of the OAGB at least 10 years after surgery.

MATERIAL AND METHODS

We retrospectively reviewed our prospectively collected data on consecutive morbid patients with obesity receiving OAGB from January 2005 to December 2007.

RESULTS

A total of 385 patients met the inclusion criteria. The mean follow-up was 149 months. Of all patients, 52% underwent OAGB as a primary procedure and 48% as a revisional procedure. At the 10-year follow-up, the mean body mass index (BMI) was 30.7 ± 11.8, the mean %TWL was 33.4 ± 10.6, and the mean %EWL was 64.1 ± 24.6. We did not find a significant statistical difference in terms of weight loss between primary OAGB and secondary OAGB. In total, 43% of patients achieved a %EWL greater than 75%, while 29% of the patients had an EWL% that was below 50%. All of the comorbidities related to obesity showed a high improvement or fully resolved. Early complications occurred in 9 patients (2.3%), while the overall rate of late complications was 17.1%. Nineteen patients (4.9%) developed an ulcer at the gastrojejunal anastomosis level, nine patients (2.3%) were re-hospitalized for major malnutrition, thirty-eight patients (9.8%) showed a postoperative biliary reflux, and five patients (2.7%) experienced severe anemia, which required several hospitalizations for iron I.V. supplementation.

CONCLUSION

According to results of the present study, we believe that OAGB has shown to be a technique with a reasonable balance between long-term efficacy and undesirable sequelae.

Early Outcomes and Mid-Term Safety of One Anastomosis Gastric Bypass Are Comparable with Roux-en-Y Gastric Bypass: a Single Center Experience

BACKGROUND

The use of one anastomosis gastric bypass (OAGB) has increased in recent years. However, the efficacy and safety outcomes of this procedure remain under debate. Here, we compare our early outcome and mid-term safety of OAGB with primary Roux-en-Y gastric bypass (RYGB).

METHODS

This was a retrospective study using computerized electronic medical records data of patients who underwent RYGB or OAGB as a primary procedure from February 2012 to February 2019 in our bariatric center. Data collected included demographics, weight-outcomes, adverse events, hospital readmission, reoperation rates, and mortality following both procedures.

RESULTS

A total of 314 patients were included (132 RYGB and 182 OAGB). Operative time and costs were significantly lower for OAGB (80 vs. 125 min, p<0.01 and 2018.8 vs. 2912.3 USD, p < 0.01, respectively), but length of hospital stay was longer (4.06 ± 0.67 days vs. 3.58 ± 0.79, p < 0.0001). At 12 months post-surgery, the percentage of excess body mass index loss was comparable between the two groups, but the change in body mass index (BMI) was significantly higher in the OAGB group. Early (< 30 days) and late (> 30 days) surgical adverse events were also similar between the two groups.

CONCLUSION

Comparable short- and mid-term outcomes and adverse events are found for primary OAGB and RYGB. OAGB is not inferior to RYGB as a primary bariatric procedure for the treatment of obesity.

Bariatric Surgery Survey 2018: Similarities and Disparities Among the 5 IFSO Chapters

BACKGROUND

The 2018 IFSO Survey focused on similarities and disparities in the number and types of surgical and endoluminal interventions among the IFSO chapters occurred in the last decade.

METHODS

All IFSO Societies were asked to fill in the IFSO survey form on how many and which surgical and endoluminal interventions have been performed in the 2018. A special section was added, asking about the existence of national guidelines for bariatric and metabolic surgery, national recommendations for preoperative gastroscopy, type of reimbursement for bariatric/metabolic surgery, including for patients with BMI < 35 kg/m². The trend analyses from 2008 to 2018 were also performed.

RESULTS

Fifty-seven/65 (87.7%) IFSO Societies submitted completed forms. The American Society for Metabolic and Bariatric Surgery did not fill the IFSO survey form but provided an official report on the performed interventions. The total number of surgical and endoluminal procedures performed in 2018 in the world was 696,191. Sleeve gastrectomy (SG) remained the most commonly performed bariatric procedure (N = 386,096; 55.4%). Among the total reported bariatric/metabolic interventions, 604,223 (86.8%) were primary surgical and 29,167 (4.2%) primary endoluminal operations; 62,801 (9%) were revisional procedures.

CONCLUSIONS

There was only a slight increase (10.317 procedures) in the total number of the reported bariatric interventions compared to the last IFSO survey. SG continues to be the most commonly performed operation since 2014. The one anastomosis gastric bypass (OAGB), currently the third most performed procedure after SG and Roux-en-Y gastric bypass (RYGB), continues to rise in popularity worldwide.

Bariatric surgery in Mexico: training, practice and surgical trends

Bariatric surgery is extremely safe and effective, but several factors need to be addressed to obtain such results. Patient selection, type of training, accreditation, type of practice, and surgical trends and technique are involved in this process. Local and global standardization are ill-advised, especially in countries with high obesity prevalence, and where the bariatric practice is fast growing.An online survey with 22 questions was sent to bariatric surgeons in Mexico. Only participants with the active practice were included, and the aim was to obtain for the first time insight in bariatric surgery training, characteristics of current practice and surgical trends.Complete responses from 114 surgeons were obtained. Most were male, under 50 years-old, ≤ 10 years of experience, and practice in low-volume hospitals. Less than half had a 12-month formal training. Gastric bypass and sleeve gastrectomy were the most common procedures. Practice trends like leak tests, use of drains, preoperative weight loss, routine endoscopy, and pharmacological tromboprofilaxis are common. In surgical technique, the gastric bypass and sleeve gastrectomy confection was more homogenic when compared to the one-anastomosis gastric bypass.Complete responses from 114 surgeons were obtained. Most were male, under 50 years-old, ≤ 10 years of experience, and practice in low-volume hospitals. Less than half had a 12-month formal training. Gastric bypass and sleeve gastrectomy were the most common procedures. Practice trends like leak tests, use of drains, preoperative weight loss, routine endoscopy, and pharmacological tromboprofilaxis are common. In surgical technique, the gastric bypass and sleeve gastrectomy confection was more homogenic when compared to the one-anastomosis gastric bypass. An important number of bariatric surgeons in Mexico are young, male, and with < 10 years of practice. The most common techniques performed are gastric bypass and sleeve gastrectomy. Several practices and technique trends are similar to global consensus. Fellowship programs and Board Certification in bariatric surgery are major advances in our country, thus standardization and high-quality practice can be achieved.

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.

Roux-en-Y gastric bypass versus one anastomosis-mini gastric bypass as a rescue procedure following failed restrictive bariatric surgery. A systematic review of literature with metanalysis

BACKGROUND

Although different procedures have been proposed as revisional surgery for patients who had previously undergone a failed primary restrictive procedure, the ideal revisional procedure is still a matter of debate.

METHODS

A systematic search was performed in all electronic databases to find studies comparing one anastomosis-mini gastric bypass (OAGB-MGB) or Roux-en-Y gastric bypass (RYGB) as revisional bariatric surgery for weight regain or intolerance/complications of a primary restrictive procedure. The data regarding sample size, patients' gender, age, primary surgery type, number of perioperative complications, operative time, pre- and post-revisional body mass index (BMI), and excess weight loss % (EWL%) at 1-year follow-up were extracted. Five studies were included in the analysis.

RESULTS

The primary bariatric procedures were represented by vertical banded gastroplasty (VBG), laparoscopic adjustable gastric band (LAGB) and laparoscopic sleeve gastrectomy (LSG). About perioperative complications, both RYGB and OAGB-MGB showed a similar rate of leaks but OAGB-MGB had a lower rate of bleedings; considering the progression from pre- to post-revisional BMI, OAGB-MGB reveals a better outcome as well as a shorter operative time.

CONCLUSIONS

Our meta-analysis has shown OAGB-MGB, used as revisional intervention after failed restrictive surgery, achieves outcomes comparable to RYGB in terms of perioperative complications providing a simpler and more effective technique.

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.

Bariatric Surgery-How Much Malabsorption Do We Need?-A Review of Various Limb Lengths in Different Gastric Bypass Procedures

The number of obese individuals worldwide continues to increase every year, thus, the number of bariatric/metabolic operations performed is on a constant rise as well. Beside exclusively restrictive procedures, most of the bariatric operations have a more or less malabsorptive component. Several different bypass procedures exist alongside each other today and each type of bypass is performed using a distinct technique. Furthermore, the length of the bypassed intestine may differ as well. One might add that the operations are performed differently in different parts of the world and have been changing and evolving over time. This review evaluates the most frequently performed bariatric bypass procedures (and their variations) worldwide: Roux-en-Y Gastric Bypass, One-Anastomosis Gastric Bypass, Single-Anastomosis Duodeno-Ileal Bypass + Sleeve Gastrectomy, Biliopancreatic Diversion + Duodenal Switch and operations due to weight regain. The evaluation of the procedures and different limb lengths focusses on weight loss, remission of comorbidities and the risk of malnutrition and deficiencies. This narrative review does not aim at synthesizing quantitative data. Rather, it provides a summary of carefully selected, high-quality studies to serve as examples and to draw tentative conclusions on the effects of the bypass procedures mentioned above. In conclusion, it is important to carefully choose the procedure and small bowel length excluded from the food passage suited best to each individual patient. A balance has to be achieved between sufficient weight loss and remission of comorbidities, as well as a low risk of deficiencies and malnutrition. In any case, at least 300 cm of small bowel should always remain in the food stream to prevent the development of deficiencies and malnutrition.

Bariatric Surgery Survey 2018: Similarities and Disparities Among the 5 IFSO Chapters

BACKGROUND

The 2018 IFSO Survey focused on similarities and disparities in the number and types of surgical and endoluminal interventions among the IFSO chapters occurred in the last decade.

METHODS

All IFSO Societies were asked to fill in the IFSO survey form on how many and which surgical and endoluminal interventions have been performed in the 2018. A special section was added, asking about the existence of national guidelines for bariatric and metabolic surgery, national recommendations for preoperative gastroscopy, type of reimbursement for bariatric/metabolic surgery, including for patients with BMI < 35 kg/m². The trend analyses from 2008 to 2018 were also performed.

RESULTS

Fifty-seven/65 (87.7%) IFSO Societies submitted completed forms. The American Society for Metabolic and Bariatric Surgery did not fill the IFSO survey form but provided an official report on the performed interventions. The total number of surgical and endoluminal procedures performed in 2018 in the world was 696,191. Sleeve gastrectomy (SG) remained the most commonly performed bariatric procedure (N = 386,096; 55.4%). Among the total reported bariatric/metabolic interventions, 604,223 (86.8%) were primary surgical and 29,167 (4.2%) primary endoluminal operations; 62,801 (9%) were revisional procedures.

CONCLUSIONS

There was only a slight increase (10.317 procedures) in the total number of the reported bariatric interventions compared to the last IFSO survey. SG continues to be the most commonly performed operation since 2014. The one anastomosis gastric bypass (OAGB), currently the third most performed procedure after SG and Roux-en-Y gastric bypass (RYGB), continues to rise in popularity worldwide.

One Anastomosis Gastric Bypass in Patients with Gastrooesophageal Reflux Disease and/or Hiatus Hernia

INTRODUCTION

One anastomosis gastric bypass (OAGB) offers favourable weight loss outcomes and is associated with reduced morbidity and mortality when compared to other mainstream bariatric procedures. However, a randomised trial reported a conversion rate to roux-en-Y configuration (RYC) of 3.1%, and some surgeons consider the procedure unsuitable for patients with a preoperative hiatus hernia (HH) or symptoms of gastrooesophageal reflux disease (GORD).

METHODS

We carried out a retrospective review of patients undergoing OAGB in our institution. Included were all patients on PPI for symptoms of GORD preoperatively, as well as patients with HH or oesophagitis on preoperative endoscopy. We recorded GORD outcomes as well as rates of conversion to RYC in patients.

RESULTS

Medium term follow up data at 23-28 months was available for 89 patients. Of these, 63 had HH, 34 had preoperative GORD requiring PPI and 9 had confirmed oesophagitis. The conversion rate to RYC was nil (0/63) in patients with HH. At the same time, 14.7% (5/34) of patients with preop GORD on PPI required conversion to RYC at a median time interval of 16 months. In patients already on PPI preoperatively, 16/34 (47.1%) needed to continue on PPI long term. In patients with HH, 20.6% (13/63) suffered de novo GORD symptoms.

CONCLUSION

OAGB can be offered to patients with HH with acceptable GORD outcomes but caution is advised in patients with preoperative GORD symptoms. Larger prospective and randomised studies are required to further assess this subgroup.

Short-term outcomes of the conversion of one anastomosis gastric bypass to Roux-en-Y gastric bypass in symptomatic reflux patients without revising the size of the gastric pouch

Background:

Revising the size of the gastric pouch during the conversion of one anastomosis gastric bypass (OAGB)/mini-gastric bypass to Roux-en-Y gastric bypass (RYGB) is an important point. Even in patients undergoing RYGB, marginal ulcer is regarded as a known complication.

Materials and Methods:

In our Centre of Excellence in Bariatric and Metabolic Surgery, 2492 patients underwent OAGB from February 2012 to January 2019. Twelve of 2492 patients were enrolled in this clinical case series because of persistent gastroesophageal reflux-like symptoms which underwent conversional RYGB. All patients regularly received proton-pump inhibitors (PPIs) for 6 months after the surgery. After this period, the cases with symptomatic reflux were invited to be visited in the clinic by a bariatric surgeon and a gastroenterologist and received 6 months of PPI therapy until their symptoms disappeared. Twelve refractory reflux cases underwent conversional RYGB after 1 year. An enteroenterostomy was created in all the patients 75 cm distal to the gastrojejunostomy without resizing the gastric pouch, and the jejunal loop was cut just before the gastrojejunostomy.

Results:

Before conversional surgery, mean ± standard deviation (SD) body mass index (BMI) and gastroesophageal reflux disease (GERD)-Q score were found to be 26.45 ± 2.34 kg/m² and 10.08 ± 0.56, respectively. At 1 year after conversion, mean ± SD BMI in the patients was 28.12 ± 4.71, and GERD-Q score was 5.08 ± 1.5.

Conclusion:

It seems that resizing the gastric pouch is not necessary during the conversion of OAGB to RYGB.

Revisional One-Anastomosis Gastric Bypass After Restrictive Index Surgery-a Metaanalysis and Comparison with Revisional Roux-en-Y Gastric Bypass

BACKGROUND

One-anastomosis gastric bypass (OAGB) was established as a recognized bariatric procedure in the 2018 International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) position statement. This study evaluates the outcomes of revisional OAGB (rOAGB) after a restrictive index procedure, and to compare it to revisional RYGB (rRYGB).

METHODS

A literature search was performed according to the PRISMA guidelines on papers published from inception till February 2020. Original studies involving patients who underwent rOAGB after a primary failed restrictive procedure were included. The primary outcome measured was postrOAGB weight loss. Secondary outcome measures include comorbidity resolution, operative duration, length of stay, morbidity, and mortality.

RESULTS

A total of 21 studies with 1377 patients were included. Five studies compared rOAGB versus rRYGB. Majority of the patients (76%) were female, with mean age of 43.5 years old. Mean body mass index (BMI) before revisional surgery was 41.6 kg/m². The most common biliopancreatic limb length was 200 cm. Percentage of excess weight loss after rOAGB increases to a maximum of 76.0% at 48 months postsurgery. rOAGB resulted in a pooled prevalence of diabetes, hypertension, hyperlipidemia, and obstructive sleep apnea resolution of 74.9%, 48.4%, 63.2%, and 75.7% respectively. When compared to rRYGB, rOAGB demonstrated greater weight loss, comparable metabolic syndrome resolution, but with a shorter operating time. Morbidity and mortality rates were low across all studies.

CONCLUSIONS

rOAGB has potential as an alternative revisional surgery, with weight loss profiles and rates of metabolic syndrome resolution that are comparable to rRYGB.

One Anastomosis/Mini-Gastric Bypass (OAGB/MGB) as Revisional Surgery Following Primary Restrictive Bariatric Procedures: a Systematic Review and Meta-Analysis

One anastomosis gastric bypass (OAGB/MGB) has gained popularity in the past decade. International databases were searched for articles published by September 10, 2020, on OAGB/MGB as a revisional procedure after restrictive procedures. Twenty-six studies examining a total of 1771 patients were included. The mean initial BMI was 45.70 kg/m², which decreased to 31.52, 31.40, and 30.54 kg/m² at 1, 3, and 5-year follow-ups, respectively. Remission of type-2 diabetes mellitus (T2DM) following OAGB/MGB at 1-, 3-, and 5-year follow-up was 65.16 ± 24.43, 65.37 ± 36.07, and 78.10 ± 14.19%, respectively. Remission/improvement rate from gastroesophageal reflux disease (GERD). Also, 7.4% of the patients developed de novo GERD following OAGB/MGB. Leakage was the most common major complication. OAGB/MGB appears to be feasible and effective as a revisional procedure after failed restrictive bariatric procedures.

The outcomes of single anastomosis sleeve jejunal bypass as a treatment for morbid obesity (Two-year follow-up)

INTRODUCTION

Santoro's operation is a sleeve gastrectomy with transit bipartition. The aim of the procedure is to keep pass to the duodenum to decrease nutritional deficiency and to allow endoscopic management of obstructive jaundice. To be easier, this procedure was rapidly altered to a single anastomosis sleeve ileal bypass (SASI). In this study, we shifted the anastomosis up to the jejunum to evaluate the effect of laparoscopic single anastomosis sleeve jejunal (SASJ) bypass as a treatment for morbid obesity and related comorbidities. In addition, the effect of the SASJ procedure on nutritional deficiency was examined.

METHODS

In this study, 150 morbidly obese patients underwent SASJ bypass with a biliary limb length of 200-250 cm. All patients were followed up at 1, 3, 6, 12, 18, and 24 months. We evaluated all cases by assessing BMI, complications, nutritional status, and obesity-related comorbidities.

RESULTS

The mean age of participants was 30.6 years, and the mean body mass index (BMI) was 44.6 kg/m². Of the patients, 35 (23.2%) had type two diabetes and 47 (31.3%) were hypertensive. Postoperative bleeding occurred in two cases (1.3%). One patient developed a gastric leak (0.7%), and five patients developed biliary gastritis (3.3%). One patient (0.7%) developed a pulmonary embolism. The %EWL reached 85% in 1 year. Normalization of blood glucose occurred within 2 months after surgery in all diabetic patients. Hypertension underwent remittance in 89% of hypertensive patients. All patients were gradually weaned from four types of multivitamin regimens to only one multivitamin regimen without apparent nutritional deficiency.

CONCLUSIONS

Laparoscopic SASJ bypass is an effective, safe, and simple procedure for treating morbid obesity and comorbid conditions with least nutritional deficiency. However, long-term studies are needed.

One anastomosis gastric bypass vs. Roux-en-Y gastric bypass: a 5-year follow-up prospective randomized trial

BACKGROUND

One anastomosis gastric bypass (OAGB) is a relatively novel technique with excellent outcomes, comparable to most accepted procedures. Our aim was to compare OAGB and Roux-en-Y gastric bypass (RYGB) in terms of percent of excess weight lost (%EWL) and resolution of comorbidities.

METHODS

Thirty-three patients were randomly assigned (1:2) to two groups (OAGB = 9 and RYGB = 24). Patients were analyzed prospectively.

RESULTS

The 5-year follow-up was 85% (28 patients). Both groups were comparable preoperatively in age, weight, body mass index (BMI), and excess weight. One intraoperative complication in OAGB group and no major postoperative complications for both groups were recorded. Progressive decrease in weight, BMI, and %EWL was observed at 1, 6, 12 months, and 5 years, with no differences between groups. Regarding comorbidities, we registered complete remission in type 2 diabetes mellitus (T2DM), insulin resistance, and dyslipidemia with OAGB. RYGB group reported complete remission in T2DM, insulin resistance, dyslipidemia, and gastroesophageal reflux disease (GERD). Mean operative time were 113.3 min ± 41.2 and 143.7 min ± 21.85 for OAGB and RYGB respectively. Mean number of reloads used was 5 for OAGB and 7 for RYGB, which demands further investigations. Postoperative pain was significantly higher in RYGB group. Hospital stay was 3 days for both groups.

CONCLUSION

At 5-year follow-up, patients of both techniques achieved similar outcomes in terms of %EWL and resolution of comorbidities, without early or mid-term major complications and no mortality. OAGB demonstrated less use of surgical stapling and unexplainably less postoperative pain compared to RYGB.

Should Surveillance Endoscopy Be Routine After One Anastomosis Gastric Bypass to Detect Marginal Ulcers: Initial Outcomes in a Tertiary Referral Centre

PURPOSE

Encouraged by the excellent outcomes of one anastomosis gastric bypass (OAGB) reported by many authors, we added this procedure to our bariatric armamentarium in 2015. Here we present our initial experience of 68 cases and findings from routine upper gastrointestinal endoscopy at 1 year.

MATERIALS AND METHODS

This is a retrospective analysis of a prospectively maintained database of a single surgical unit in a tertiary referral centre. Patients undergoing OAGB from January 2015 to May 2019 were included. A fixed biliopancreatic (BP) limb length of 200 cm was used in all patients. Surveillance endoscopy was done at 1-year follow-up.

RESULTS

Sixty-eight patients, of whom 67.6% were females, were analysed. Mean age was 40.8 ± 1 years. Mean preoperative weight and body mass index (BMI) were 131 ± 24.7 kg and 51 ± 7 kg/m², respectively. Median follow-up was 23 months (range 9-55 months), with 88% follow-up at 6 months and 1 year. At 1 year, mean total weight loss (TWL) and excess weight loss (EWL) were 35% and 71%, respectively. Endoscopy at 1 year revealed a 9.5% rate of marginal ulcers, majority of which healed with conservative treatment. Eighty-eight percent patients had complete remission of diabetes, and 94% had complete remission of hypertension. There was no 30-day mortality.

CONCLUSION

OAGB is a safe and effective bariatric procedure with excellent short-term outcomes in terms of weight loss, resolution of obesity-related co-morbidities and complications. Routine surveillance endoscopy at 1 year may detect asymptomatic marginal ulcers and, thus, prevent ulcer-related complications.

Postoperative Clinical-Endoscopic Follow-up for GERD and Gastritis After One Anastomosis Gastric Bypass for Morbid Obesity: How, When, and Why

INTRODUCTION

The one anastomosis gastric bypass (OAGB) is a widely diffused surgical procedure for morbid obesity. Several studies considered OAGB at risk for biliary reflux and anastomotic ulcers. The aim of the study was to evaluate gastro-esophageal reflux disease (GERD) and esophagitis/gastritis rate after OAGB diagnosed by upper endoscopy (UE), comparing the results with GERD-Health-Related Quality of Life (HRQL) score.

METHODS

From July 2014 to February 2019, patients underwent OAGB with at least 12-month follow-up were retrospectively evaluated. Clinical evaluation was associated with GERD-HRQL scoring. UE with a mucosal biopsy was also performed. A comparison among clinical scores and endoscopic findings was performed.

RESULTS

Two hundred forty-one patients were analyzed in the study. Anthropometric features (BMI, %Excess weight loss, %Total weight loss) were significantly improved. Only 30% of patients with GERD-HQRL>30 showed esophagitis at UE: 11/181 (6.1%) showed grade A erosive esophagitis, 2/181 (1.1%) grade B esophagitis, whereas no patient resulted in grade C/D. Fifty-two patients (28.7%) showed endoscopic remnant gastritis of at least grade 1, with histological gastritis of at least mild grade in 70/181 patients (38.7%).

CONCLUSION

OAGB is a feasible and effective procedure in terms of weight reduction and comorbidities control, but controversies remain about the long-term onset of GERD and bile reflux. The incidence of esophagitis was increased after OAGB. However, the severity and incidence were lower compared to sleeve gastrectomy. Conversely, the incidence of gastritis, ileo-gastric anastomotic inflammation, and HP positivity were not negligible, suggesting the potential benefits of endoscopic surveillance after OAGB.

The rise of one anastomosis gastric bypass: insights from surgeons and dietitians

One anastomosis gastric bypass/Mini Gastric Bypass (OAGB/MGB) is an emerging bariatric surgery (BS) technique. We evaluated and compared attitudes of bariatric surgeons and dietitians towards the considerations for choosing BS-type ("Decision-making"), the contributing factors to the rise of OAGB/MGB in Israel ("OAGB/MGB-rise") and notions regarding the occurrence of gastrointestinal (GI) symptoms and nutritional deficiencies following OAGB/MGB. Anonymous online surveys were distributed. The participants were asked to rate by a 10-point Likert scale (0 = not at all; 100 = very much/often) their attitudes towards "Decision-making", "OAGB/MGB-rise" and occurrence of GI symptoms and nutritional deficiencies following OAGB/MGB. For "Decision-making" and "OAGB/MGB-rise", items were considered prioritized where ≥ 50% of the group considered them as 'very-important' (rating ≥ 80). Data on age, sex, years-in-practice and main workplace were also collected. A total of 106 professionals participated in the survey (42 surgeons; 64 dietitians). The respective mean age, years-in-practice and sex were 52.3 ± 8.7 vs. 42.3 ± 9.0 years, 21.0 ± 10.8 vs. 15.5 ± 9.2 years and 85.7% vs. 3.1% males. The inter-observer agreement for prioritized items related to "Decision-making" was fair (Kappa = 0.250; P = 0.257) and both groups prioritized patient's BMI, comorbidities and compliance. The inter-observer agreement for prioritized items related to "OAGB/MGB-rise" was moderate (Kappa = 0.550; P = 0.099) and both groups prioritized ease of performance, shorter operation duration and failure of former restrictive BS. Surgeons reported lower occurrence of nutritional deficiencies and GI symptoms as adverse effects of OAGB/MGB (P ≤ 0.033). The study highlights the views of bariatric surgeons and dietitians concerning factors that underpin the rise of OABG/MGB in Israel and possible rates of GI symptoms and nutritional deficiencies associated with this modality.

Chylous ascites as a late complication of one anastomosis gastric bypass-minigastric bypass: case report

Background

One anastomosis gastric bypass- minigastric bypass (OAGB-MGB) is an emerging bariatric surgery that is being endorsed by surgeons worldwide. Internal herniation is a rare and dreaded complication after malabsorptive bariatric procedures, which necessitates early diagnosis and intervention.

Case presentation

We describe a 29-year-old male with chylous ascites caused by an internal hernia 8 months following laparoscopic one anastomosis gastric bypass. An abdominal CT showed enlargement of lymph nodes at the mesentery, with a moderate amount of liquid in the abdomen and pelvis. An emergent exploratory laparoscopic surgery demonstrated an internal hernia at the Petersen’s space with a moderate quantity of chylous ascites. The patient made an uneventful recovery after surgery.

Conclusions

Internal herniation can occur after OAGB-MGB and in extremely rare cases lead to chylous ascites. To our knowledge, this is the first reported case of chylous ascites following one anastomosis gastric bypass.