One thousand consecutive mini-gastric bypass: short- and long-term outcome

Update on esophageal function, acid and non-acid reflux after one-anastomosis gastric bypass (OAGB): high-resolution manometry, impedance-24-h pH-metry, and gastroscopy in a prospective mid-term study

BACKGROUND

One-anastomosis gastric bypass (OAGB) is the third most common metabolic/bariatric procedure worldwide. A point for discussion regarding OAGB is acid and non-acid reflux in mid- and long-term follow-up. The aim of this study was to objectively evaluate reflux and esophagus motility by comparing pre- and postoperative results of 24-h pH-metry, high-resolution manometry (HRM), and gastroscopy.

SETTING

Cross-sectional study and university hospital based.

METHODS

This study includes primary OAGB patients operated at the Medical University of Vienna before 31st December 2022. After a mean follow-up of 4.1 ± 2.9 years, the preoperative examinations were repeated. Additionally, history of weight, remission of obesity-related complications (ORC), and quality of life (QOL) were evaluated.

RESULTS

A total of 50 patients were included in this study and went through all examinations. Preoperative weight was 125.5 ± 21.0 kg with a BMI of 44.6 ± 5.4 kg/m2 and total weight loss after 4.1 ± 2.9 years was 37.1 ± 8.1%. Remission of ORC and QOL outcomes was successful in all categories. Gastroscopy showed anastomositis, esophagitis, Barrett's esophagus, and bile in the pouch in 38.0%, 34.0%, 6.0%, and 48.0%, respectively. In HRM, the postoperative lower esophageal sphincter pressure was 29.6 ± 15.1 mmHg (unchanged to preoperative). The total number of refluxes was equal to preoperative, whereas decreased acid refluxes were replaced by increasing non-acid refluxes. Impedance-24-h pH-metry showed that acid exposure time of the esophagus and DeMeester score decreased significantly to 1.6 ± 1.4% (p = 0.001) and 10.3 ± 9.6 (p = 0.046).

CONCLUSION

This study has shown decreased rates of acid reflux and increased rates of non-acid reflux after a mid-term outcome of primary OAGB patients. Gastroscopy showed significant signs of chronic reflux exposure of the anastomosis, the pouch, and the distal esophagus, even in asymptomatic patients. General follow-up visits in patients after OAGB should be considered.

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

BACKGROUND

One Anastomosis Gastric Bypass (OAGB) is a modification of Mason's loop bypass procedure, which has become a well-established procedure in the field of Bariatric and Metabolic surgery (BMS). However, the optimal length of Biliopancreatic Limb (BPL) in OAGB remains an ongoing debate.

OBJECTIVE

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

METHODS

A comprehensive literature search using search terms, 'One Anastomosis Gastric Bypass', 'Mini-Gastric Bypass', 'Biliopancreatic Limb', and 'Small bowel limb' was conducted. The articles were extracted and critically appraised for various outcomes including weight loss, comorbidities resolution, nutritional deficiencies, complications and quality of life.

RESULTS

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

CONCLUSION

Shorter BPL lengths offer potential advantages by reducing nutritional risks associated with OAGB. Further research with long-term follow-up is needed to investigate the efficacy of even shorter BPL lengths (< 150 cm).

Primary, revisional, and endoscopic bariatric surgery: a narrative review of abdominal emergency management for general surgeons

Minimally invasive approaches like endoscopic, laparoscopic, and robotic surgery have revolutionized bariatric and metabolic surgery (MBS). Despite the safety of MBS in specialized centers, acute complications requiring emergency treatment may occur and present challenges for general surgeons, especially in community hospitals. This is further complicated by the rising popularity of bariatric surgery tourism and the increasing diversity of bariatric surgical techniques. This paper provides an updated review of the management of acute abdominal complications after minimally invasive MBS, intending to guide general surgeons in managing these patients, especially in emergency settings where specialized bariatric care may not be readily available.

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

BACKGROUND

Tailoring the biliopancreatic limb length in one anastomosis gastric bypass is proposed as beneficial in retrospective studies, yet randomized trials are lacking. The aim of this double-blind, single-centre RCT was to ascertain whether tailoring biliopancreatic limb length based on total small bowel length (TSBL) results in superior outcomes after one anastomosis gastric bypass compared with a fixed 150 cm biliopancreatic limb length.

METHODS

Eligible patients, meeting International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) criteria for metabolic bariatric surgery, scheduled for primary one anastomosis gastric bypass surgery, and willing to be randomized, underwent TSBL measurement during surgery. When TSBL measurement was feasible, patients were randomly assigned to a standard 150 cm biliopancreatic limb length or a tailored biliopancreatic limb based on TSBL: TSBL less than 500 cm, biliopancreatic limb 150 cm; TSBL 500-700 cm, biliopancreatic limb 180 cm; and TSBL greater than 700 cm, biliopancreatic limb 210 cm. The primary outcome was percentage total weight loss at 5 years.

RESULTS

Between September 2020 and August 2022, 212 patients were randomized into the standard biliopancreatic limb group (105 patients) or the tailored biliopancreatic limb group (107 patients). The mean(s.d.) TSBL was 657(128) cm (range 295-1020 cm). In the tailored group, 150, 180, and 210 cm biliopancreatic limb lengths were applied to 8.4%, 53.3%, and 38.3% of patients respectively. The mean(s.d.) 1-year percentage total weight loss was 32.8(6.9)% in the standard group and 33.1(6.2)% in the tailored group (P = 0.787). Nutritional deficiencies and short-term complications showed no significant differences.

CONCLUSION

Tailoring biliopancreatic limb length based on TSBL is safe and feasible. One year after surgery, it is not superior to a standard biliopancreatic limb length of 150 cm in terms of percentage total weight loss.

REGISTRATION NUMBER

Dutch Trial Register, NL7945.

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.

The predictive relationship between early and long-term weight loss outcomes after one anastomosis gastric bypass

BACKGROUND

Weight loss failure after bariatric surgery imposes great stress on patients and surgeons and great costs on healthcare systems. The literature review shows that weight loss failure is the most common cause of redo bariatric surgery. Therefore, identifying the predictors of weight loss failure in patients in the early stages can help bariatric surgeons. The present study aims to determine the association between primary weight loss and long-term weight loss outcomes.

METHODS

This retrospective cohort study was conducted on 329 patients undergoing OAGB who were followed for 60 months. For the prediction of short-term (24 months) and long-term (60 months) successful weight loss and weight regain, we used %TWL and BMI at any regular follow-ups.

RESULTS

In preoperative indices, age, sex, DLP, hypothyroidism, and HTN were not significant to predict successful short-term and long-term weight loss but %TWL at 12 months is a significant predictor of successful weight loss in short-term and long-term follow up. In the prediction of weight regain, preoperative indices (except BMI) were not significant but 12-month %TWL was a significant predictor.

CONCLUSIONS

This index can help surgeons find these patients early and provide helpful instructions to manage their issues more promptly to reach better weight loss outcomes.

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

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

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

Medtronic.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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 (OAGB) with a 150-cm Biliopancreatic Limb (BPL) Versus a 200-cm BPL, a Systematic Review and Meta-analysis

This is a systematic review and meta-analysis that assessed the impact of performing OAGB with a 150-cm BPL versus a 200-cm BPL concerning weight loss, comorbidities remission, and adverse nutritional effects. The analysis included studies that compared patients who underwent OAGB with a 150-cm BPL and 200-cm BPL. Eight studies were eligible for this review after searching in the EMBASE, PubMed central database, and Google scholar. The pooled analysis revealed favoring the 200-cm BPL limb length for weight loss, with a highly significant difference in the TWL% (p=0.009). Both groups showed comparable comorbidities remission. Significantly higher ferritin and folate deficiency rates were found in the 200-cm BPL group. Considering a 200-cm BPL when performing OAGB delivers a better weight loss outcome than a 150-cm BPL, which is at the expense of a more severe nutritional deficiency. No significant differences were found regarding the comorbidities' remission.

Management of leaks following one-anastomosis gastric bypass: an updated systematic review and meta-analysis of 44 318 patients

INTRODUCTION

One-anastomosis gastric bypass (OAGB) complication, such as leakage, can be dangerous and should be managed properly, yet little data exist in the literature regarding the management of leaks after OAGB, and there are no guidelines to date.

METHODS

The authors performed a systematic review and meta-analysis of the literature and 46 studies, examining 44 318 patients were included.

RESULTS

There were 410 leaks reported in 44 318 patients of OAGB published in the literature, which represents a prevalence of 1% of leaks after OAGB. The surgical strategy was very variable among all the different studies; 62.1% of patients with leaks had to undergo another surgery due to the leak. The most commonly performed procedure was peritoneal washout and drainage (with or without T-tube placement) in 30.8% of patients, followed by conversion to Roux-en-Y gastric bypass in 9.6% of patients. Medical treatment with antibiotics, with or without total parenteral nutrition alone, was conducted in 13.6% of patients. Among the patients with the leak, the mortality rate related to the leak was 1.95%, and the mortality due to the leak in the population of OAGB was 0.02%.

CONCLUSION

The management of leaks following OAGB requires a multidisciplinary approach. OAGB is a safe operation with a low leak risk rate, and the leaks can be managed successfully if detected in a timely fashion.

Standardization of the One-anastomosis Gastric Bypass Procedure for Morbid Obesity: Technical Aspects and Early Outcomes

BACKGROUND

One-anastomosis gastric bypass (OAGB) has become an accepted metabolic/bariatric surgery procedure. This study aimed to describe our center's standardized OAGB operative technique and report early (≤30 d) safety outcomes in patients with severe obesity.

METHODS

The medical records of patients who had undergone either primary (n=681, 88.0%) or revisional OAGB (n=93, 12.0%) were retrospectively evaluated. Patient demographics, operative time, length of hospital stay, readmissions, reoperations, and ≤30-day morbidity and mortality rates were analyzed.

RESULTS

A total of 774 consecutive patients with severe obesity (647 female, 83.6%) underwent OAGB between January 2016 and December 2021. Their mean age was 36.2±10.8 years (range: 18 to 70 y) and mean body mass index was 42.7±4.2 kg/m 2 (range: 17.2 to 61 kg/m 2 ). Mean operating time was 52.6±19.9 minutes (range: 25 to 295 min) and length of hospital stay was 1.6±0.9 days (range: 1 to 9 d). Early postoperative complications occurred in 16 cases (2.1%), including 2 leaks with an intra-abdominal abscess (0.3%), bleeding (n=3, 0.4%), acute kidney failure (n=1, 0.15%), urinary tract infection (n=2, 0.3%), and intensive care unit stay (n=4, 0.5%). Seventy patients (9.1%) were readmitted, and re-laparoscopy was performed in 1 patient (0.1%). There was no mortality.

CONCLUSIONS

In the very early term, OAGB was a safe primary and revisional metabolic/bariatric surgery operation. Consistent performance of a standardized OAGB procedure contributed to low rates of morbidity and mortality in the hands of metabolic/bariatric surgeons with good laparoscopic skills at a high-volume center.

Endoscopic and histopathological assessment of individuals undergoing one anastomosis gastric bypass: a 2-year follow-up

BACKGROUND

There is much debate over the occurrence of biliary reflux to the gastric pouch after one anastomosis gastric bypass (OAGB) and its potential risks.

OBJECTIVE

To assess endoscopic and histopathological findings following a standardized protocol of biopsy collection two years after OAGB.

METHODS

A historical cohort study was conducted, based on a prospectively collected database, which involved 39 participants who underwent OAGB. Participants underwent clinical evaluation and esophagogastroduodenoscopy at the time of surgery and 24 months afterward. Post-operatively, biopsy specimens in esophagogastric junction, pouch, and anastomosis were systematically collected.

RESULTS

92.3% of the participants were female and the mean age was 37 ± 8.5 years. The mean body mass index (BMI) significantly decreased from 37.6 ± 5.7 kg/m² to 27 ± 4.1 kg/m² after 2 years (p < 0.001). The mean %TWL was 27.2 ± 10.5%. The prevalence of non-erosive gastritis significantly increased from 25.6 to 51.3% (p = 0.02). Erosive gastritis significantly decreased from 28.2 to 10.3% (p = 0.04). Four cases of marginal ulcers were identified (10.3%). The commonest histopathological finding was mild inflammation in 74.3% (esophagogastric junction), 58.9% (pouch), and 71.8% (anastomosis). There was one case of focal intestinal metaplasia in each site of interest and no cases of dysplasia or severe inflammation.

CONCLUSIONS

Using a standardized protocol of post-operative biopsy collection, low rates of severe endoscopic and histopathological abnormalities were observed two years after OAGB. Nevertheless, as most patients have histologically proven inflammation, bile in the gastric pouch, and endoscopic gastritis, long-term surveillance is essential because of the uncertain risk of these abnormalities.

A Long-Term Comparative Study Between One Anastomosis Gastric Bypass and Sleeve Gastrectomy

BACKGROUND

One anastomosis gastric bypass (OAGB) has become increasingly accepted in bariatric surgery and meanwhile represents the third most common procedure worldwide. While it shows promising weight loss results and comorbidity resolution, questions about issues such as reflux or nutritional deficiencies (ND) persist in the long term. On the other hand, the most frequently performed sleeve gastrectomy (SG) has to accept growing criticism regarding long-term results and reflux issues. There is a particular lack of long-term comparative data for both procedures. This study presents our long-term experience.

METHODS

We evaluated OAGB and SG patients retrospectively comparing for weight loss and resolution of comorbidities as well as perioperative and long-term complications in a follow-up period of 5 years.

RESULTS

Nine hundred eleven OAGB and 241 SG were included in the study. OAGB had a shorter operation time and hospital stay. Overall complication rate did not differ in both groups. Ulcers were more frequent in OAGB (7.7% vs. 1.7%, p = 0.001), whereas insufficient weight loss (IWL)/weight regain (WR) proved to be more prevalent in SG (25.7% vs. 6.4%, p < 0.001). The same held true for reflux (17.8% vs. 8.3%, p < .001). On the other hand, ND were more common in OAGB (20.0% vs. 12.0%, p = 0.005). Revisional surgery was more often indicated after SG. Analysis by linear mixed model showed that OAGB achieved a lower BMI/higher loss of BMI. Improvement of T2DM (94.6% vs. 85.2%, p = 0.008) and sleep apnea (88.8% vs. 78.8%, p = 0.01) was superior in OAGB.

CONCLUSIONS

OAGB had a superior effect on weight loss as well as improvement of T2DM and sleep apnea. Furthermore, long-term problems such as IWL/WR and reflux were more related to SG. On the other hand, a malabsorptive procedure such as OAGB showed a higher risk for ND. Our findings support the available data in the literature.

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

Background

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

Methods

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

Discussion

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

Trial registration

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

Supplementary Information

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

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.

Challenges in Bariatric Surgery: Outcomes in Patients Having Three or More Bariatric Procedures

INTRODUCTION

Over the last two decades, a progressive increase in failure rate of bariatric surgery (BS) has occurred in conjunction with an exponential increase in BS worldwide. Bariatric surgeons are confronted with challenging situations in patients with a complex bariatric history. In this study, we aim to evaluate the feasibility and outcomes of revisional BS in patients with at least two or more previous bariatric procedures.

METHODS

Data were retrospectively retrieved from a prospectively held database of bariatric procedures performed at our tertiary referral bariatric center and included procedures done from February 2013 up to April 2019 by a single center.

RESULTS

Thirty patients underwent a third bariatric procedure. The median age was 40 (18-57) and 54 (27-69) years at the time of the first and the last procedures, respectively. Laparoscopic adjustable gastric banding was the first procedure in 26 patients. The complication rate was 33%; no patient required additional surgery because of postoperative complications. A total weight loss of 29.6% and an excess loss of 53.4% were obtained at a mean follow-up of 61 months after the last redo bariatric procedure.

CONCLUSION

This study indicates that redo BS either conversional or revisional is feasible and effective in patients with a complex bariatric history including two or more previous procedures. Careful patients' selection is mandatory and extensive information should be given on the increased risk of postoperative complications.

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

Background

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

Materials and Methods

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

Results

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

Conclusions

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

Graphical abstract

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

OBJECTIVE

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

METHODS

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

RESULT

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

CONCLUSION

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

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.

Gastroesophageal Cancer After Gastric Bypass Surgeries: a Systematic Review and Meta-analysis

Data comparing the occurrence of gastroesophageal cancer after gastric bypass procedures are lacking and are only available in the form of case reports. We perform in this study a systematic review and a meta-analysis of all the reported cases of gastroesophageal cancer following Roux-en-Y gastric bypass (RYGB) and loop gastric bypass-one anastomosis gastric bypass/mini gastric bypass (LGB-OAGB/MGB). We conducted a systematic review of all the reported cases in articles referenced in PubMed/Medline, Cochrane, and Scholar Google. Only cases of gastro-esophageal adenocarcinoma following RYGB or LGB-OAGB/MGB are included. Statistical analysis was done accordingly. Fifty cases were identified, along with 2 reported in this paper. Sixty-one percent (27/44) of the cancers after RYGB were in the gastric tube compared to 37.5% (3/8) after LGB-OAGB/MGB. This resulted in an odds ratio of 0.38 (p-value = 0.26), which failed to prove an increase in cancer occurrence in the gastric tube after LGB-MGB/OAGB compared to RYGB. The most common symptoms were dysphagia for cancers occurring in the gastric tube (15/30) and abdominal pain for those occurring in the excluded stomach (10/22). Twenty-nine/thirty of the cancers in the gastric tube were diagnosed by gastroscopy and 13/22 of the cancers in the excluded stomach were diagnosed by CT scan. Gastroesophageal cancers after gastric bypass procedures occur commonly in the excluded stomach where many are not identified by conventional means. Physician awareness and patient education as well as lifelong follow-up are essential for maintaining bypass surgeries on the beneficial side.

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.

Clinical outcomes after one anastomosis gastric bypass versus sleeve gastrectomy in super-super-obese patients

BACKGROUND

Bariatric surgery in super-super-obese (SSO) patients remains a continuous challenge due to intraabdominal fat masses, higher liver volume and existing comorbidities. A convenient procedure in SSO patients is one anastomosis gastric bypass (OAGB). The aim of this study was to compare the outcome of SSO patients undergoing OAGB in comparison to laparoscopic sleeve gastrectomy (LSG).

METHODS

We retrospectively reviewed data from SSO patients who underwent OAGB and LSG in our institution between 2008 and 2020. Primary endpoints included percentage total body weight loss and percentage BMI loss at 12, 24, and 36 months after the operation. Secondary endpoints were perioperative complications, procedure length, length of hospital stay and outcome of comorbidities.

RESULTS

243 patients were included in this study. 93 patients underwent LSG and 150 underwent OAGB. At any of the time points evaluated, weight loss in patients after OAGB was greater than in LSG patients, while procedure length was significantly shorter for OAGB than LSG (81.4 vs. 92.1 min, p-value < 0.001). Additionally, mean length of hospital stay was shorter in the OAGB group (3.4 vs. 4.5 days, p-value < 0.001). There were more severe complications (Clavien-Dindo ≥ 3a) in the LSG group (11.8% vs 2.7%, p-value = 0.005).

CONCLUSION

In this retrospective analysis, OAGB was superior to LSG in terms of weight loss in SSO patients. Procedure length and hospital stay were shorter after OAGB in comparison to LSG and there were fewer severe complications. OAGB can therefore be regarded a safe and effective treatment modality for SSO patients.

Computational modelling of self-reported dietary carbohydrate intake on glucose concentrations in patients undergoing Roux-en-Y gastric bypass versus one-anastomosis gastric bypass

OBJECTIVES

Our aim was to investigate in a real-life setting the use of machine learning for modelling the postprandial glucose concentrations in morbidly obese patients undergoing Roux-en-Y gastric bypass (RYGB) or one-anastomosis gastric bypass (OAGB).

METHODS

As part of the prospective randomized open-label trial (RYSA), data from obese (BMI ≥35 kg/m2) non-diabetic adult participants were included. Glucose concentrations, measured with FreeStyle Libre, were recorded over 14 preoperative and 14 postoperative days. During these periods, 3-day food intake was self-reported. A machine learning model was applied to estimate glycaemic responses to the reported carbohydrate intakes before and after the bariatric surgeries.

RESULTS

Altogether, 10 participants underwent RYGB and 7 participants OAGB surgeries. The glucose concentrations and carbohydrate intakes were reduced postoperatively in both groups. The relative time spent in hypoglycaemia increased regardless of the operation (RYGB, from 9.2 to 28.2%; OAGB, from 1.8 to 37.7%). Postoperatively, we observed an increase in the height of the fitted response curve and a reduction in its width, suggesting that the same amount of carbohydrates caused a larger increase in the postprandial glucose response and that the clearance of the meal-derived blood glucose was faster, with no clinically meaningful differences between the surgeries.

CONCLUSIONS

A detailed analysis of the glycaemic responses using food diaries has previously been difficult because of the noisy meal data. The utilized machine learning model resolved this by modelling the uncertainty in meal times. Such an approach is likely also applicable in other applications involving dietary data. A marked reduction in overall glycaemia, increase in postprandial glucose response, and rapid glucose clearance from the circulation immediately after surgery are evident after both RYGB and OAGB. Whether nondiabetic individuals would benefit from monitoring the post-surgery hypoglycaemias and the potential to prevent them by dietary means should be investigated.KEY MESSAGESThe use of a novel machine learning model was applicable for combining patient-reported data and time-series data in this clinical study.Marked increase in postprandial glucose concentrations and rapid glucose clearance were observed after both Roux-en-Y gastric bypass and one-anastomosis gastric bypass surgeries.Whether nondiabetic individuals would benefit from monitoring the post-surgery hypoglycaemias and the potential to prevent them by dietary means should be investigated.

Early and intermediate term outcomes after laparoscopic one-anastomosis gastric bypass for morbidly obese patients: a single center experience

OBJECTIVES

To evaluate our outcomes of laparoscopic one-anastomosis gastric bypass (LOAGB) as a primary weight loss procedure. We evaluated the impact of biliary reflux by combination of upper endoscopy (UGIE), ambulatory pH metry, and ambulatory biliary reflux monitoring.

MATERIAL AND METHODS

We reviewed the data of patients who underwent LOAGB during the period between July 2015 till August 2018.

RESULTS

Forty consecutive patients were included in the study. Thirty-seven patients (92.5%) had obesity related comorbidities. The median follow-up duration was 18 months (6-36 months). The 1-, 2-, and 3-years excess weight loss percentages were 53.1%, 60.4%, and 62.3%. At three years follow-up, complete remission of diabetes mellitus occurred in 7/7 patients (100%) and of hypertension in 4/7 patients (57.1%). Eighteen patients (45%) accepted to undergo UGIE with routine biopsies and evaluation of acidic and biliary reflux. All examined patients had negative acid reflux results according to ambulatory PH metry with median DeMeester score of 2 (0.3-8.7). According to ambulatory biliary reflux monitoring, 17/18 patients (94.1%) had posi- tive result. Only 6/18 patients (33.3%) had symptoms of biliary reflux and had positive symptom index on bilimetric study. Regarding UGIE, all patients had just gastritis and reflux esophagitis with no evidence of gross mucosal changes. Pathological examination of all routine biopsies did not show any sign of faveolar hyperplasia, atypia or malignancy.

CONCLUSION

LOAGB is a safe and efficient bariatric procedure with acceptable morbidity rate. LOAGB is not associated with significant biliary reflux or pathological changes in the esophagogastric mucosa.

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.

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.

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.

Long-Term Efficacy of Bariatric Surgery for the Treatment of Super-Obesity: Comparison of SG, RYGB, and OAGB

BACKGROUND

The most appropriate procedure for the treatment of super obesity (BMI > 50 kg/m²) is unknown. We aimed to evaluate the safety, long-term (> 5 years) weight loss, and adverse events between three commonly performed procedures, sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB) in super-obese patients.

METHODS

Between January 2002 and December 2015, 498 successive patients with super morbid obesity (BMI > 50), who underwent SG or RYGB or OAGB, were recruited. Surgical outcome, weight loss, resolution of co-morbidities, and late complications were followed and compared between the 3 groups. All data derived from a prospective bariatric database and a retrospective analysis was conducted.

RESULTS

The average patient age was 32.1 ± 10.4 years, with a mean body mass index (BMI) of 56.0 ± 6.7 kg/m². Of them, 190 (38.9%) underwent SG, 62 (12.4%) RYGB, and 246 (49.4%) OAGB. There was no difference in basic characters between the 3 groups except SG had fewer diabetic patients. RYGB group had higher intraoperative blood loss, longer operating time, and hospital stay than the other 2 groups. RYGB had a higher 30-days post-operative major complication rate (4.8%) than SG (0.5%) and OAGB (0.8%). The follow-up rate at 1 and 5 years was 89.4% and 52.0%. At post-operative 5 years, OAGB had a higher total weight loss (40.8%) than SG (35.1%), but not RYGB (37.2%). SG had a lower remission rate in dyslipidemia comparing to OAGB and RYGB, but T2DM remission rate was no different between the groups. The overall revision rate is 5.4% (27/498) of the whole group, and SG had a lower revision rate (2.6%) than RYGB (8.1%) and OAGB (6.9%).

CONCLUSION

SG is an effective and durable primary bariatric procedure for the treatment of super obesity and metabolic disorders. OAGB had a similar operation risk to SG but resulted in a better weight loss than SG.

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.

Long-Term Evaluation of Biliary Reflux on Esogastric Mucosae after One-Anastomosis Gastric Bypass and Esojejunostomy in Rats

BACKGROUND

One-anastomosis gastric bypass/mini-gastric bypass (OAGB/MGB) remains controversial because it may cause chronic biliary reflux (BR). The risk of developing esogastric cancer due to BR after OAGB/MGB is based on the results of experimental rat studies using esojejunostomy (EJ). The aim of this study was to analyze the potential long-term consequences of BR on the esogastric mucosae in OAGB/MGB-operated rats and to compare these results to those from the use of EJ.

METHODS

Wistar rats received OAGB/MGB (n = 16), EJ (n = 16), and sham (n = 8) operations. Mortality and weight changes were evaluated throughout the experiment. BR was measured using magnetic resonance imaging (MRI). Rats received follow-ups for 30 weeks. A double-blinded histological analysis was performed in the esogastric segments.

RESULTS

BR was diagnosed in OAGB/MGB and EJ rats using the MRI technique; no BR occurred in the sham group. After a 30-week follow-up, no incidences of dysplasia or cancer were observed in the three groups. Additionally, esophageal intestinal metaplasia and mucosal ulcerations were observed in 41.7% and 50% of EJ rats, respectively, and no incidences of these conditions were observed in OAGB/MGB and sham rats. The incidence of esophagitis was significantly higher and more severe in the EJ group compared to those in the OAGB/MGB and sham groups (EJ = 100%, OAGB/MGB = 16.7%, sham = 8.3%; p < 0.001).

CONCLUSIONS

After a 30-week follow-up period, OAGB/MGB rats did not develop any precancerous or cancerous lesions when more than 40% of EJ rats had intestinal metaplasia.

Role of Imaging in Bariatric Surgery: A Review of the Various Surgical Techniques and Their Complications

According to the World Health Organization, obesity has reached epidemic proportions globally, with at least 2.8 million people dying each year as a result of being overweight or obese. Bariatric surgery is being increasingly used as a form of treatment, particularly in those patients where lifestyle modifications are deemed insufficient. With the role of radiologists transitioning from a medical to a surgical evaluation in obesity, it is becoming increasingly important to familiarize oneself with the various imaging techniques used in the preoperative and postsurgical evaluation in such cases. This article aims to review the various surgeries performed, their normal imaging appearance, and the various complications that could be encountered.

The IFSO Worldwide One Anastomosis Gastric Bypass Survey: Techniques and Outcomes?

INTRODUCTION

One anastomosis gastric bypass (OAGB) has become one of the most commonly performed gastric bypass procedures in some countries.

OBJECTIVES

To assess how surgeons viewed the OAGB, perceptions, indications, techniques, and outcomes, as well as the incidence of short- and long-term complications and how they were managed worldwide.

METHODS

A questionnaire was sent to all IFSO members in all 5 chapters to study the pattern of practice and outcomes of OAGB.

RESULTS

Seven hundred and forty-two surgeons responded. The most commonly performed procedures were sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and OAGB. Preoperatively, 70% of the surgeons performed endoscopy routinely. In regards to weight loss, 83% (570 surgeons) responded that OAGB produces better weight loss than SG, and 49% (342 surgeons) responded that OAGB produces better weight loss than RYGB. The most common length of the biliopancreatic limb (BPL) utilized was 200 cm. Sixty-seven percent of surgeons did not measure the total length of the small bowel. In patients with reflux disease and history of smoking, 53% and 22% of surgeons respectively still offered OAGB as a treatment option. Postoperatively, leak was documented in 963 patients, and it was the leading cause for mortality. Leak management was conservative in 35%. Conversion to RYGB was performed in 31%. In 16% the anastomosis was reinforced, 6% of the patients were reversed, and other procedures were performed in 12%. Revision of OAGB for malnutrition/steatorrhea or severe bile reflux was reported at least once by 37% and 45% of surgeons, respectively (200 cm was the most commonly encountered biliopancreatic limb BPL in those revised for malnutrition). Most common strategy for revision was conversion to RYGB (43%), reversal to normal anatomy (32%), shortening of the BPL (20%), and conversion to SG (5%). Nevertheless, 5 out of 98 mortalities (5%) were due to liver failure/malnutrition.

CONCLUSION

There are infrequent but potentially severe specific complications including malnutrition, liver failure, and bile reflux that may require surgical correction after OAGB.

Applying an Anti-reflux Suture in the One Anastomosis Gastric Bypass to Prevent Biliary Reflux: a Long-Term Observational Study

INTRODUCTION

The one anastomosis gastric bypass (OAGB) is an effective treatment to induce sustained weight loss in morbidly obese patients. Concerns remain regarding the development of reflux. The aim of this study was to investigate the effect of an "anti-reflux suture" as anti-reflux modification to prevent reflux.

METHOD

This is a single-center retrospective cohort study of patients who underwent a primary OAGB at the Center Obesity North-Netherlands (CON) between January 2015 and December 2016. Reflux was defined as symptoms of acid/bilious regurgitation or pyrosis. This was consequently asked and reported at each follow-up visit. Outcomes of patients with an anti-reflux suture were compared to those without.

RESULTS

In 414 (59%) of the 703 included patients, an anti-reflux suture was applied. Follow-up at 3 years was 74%. The incidence of reflux did not differ between patients with or without an anti-reflux suture (57 versus 56%, respectively; P = 0.9). The presence of an anti-reflux suture was significantly associated with a lower incidence of conversion to Roux-en-Y gastric bypass (RYGB) for reflux (OR 0.56, 95%CI 0.34-0.91). Patients preoperatively diagnosed with gastroesophageal reflux disease (GERD) were 5.2 times more likely to need a conversion to RYGB for reflux (95%CI 2.7-10.1).

CONCLUSION

The presence of preoperative GERD should be weighted heavily in the decision to perform an OAGB as this is a major risk factor for conversion surgery due to reflux. The anti-reflux suture might be a valuable addition to the procedure of the OAGB because it results in fewer conversion surgeries for reflux.

Twenty years' experience of laparoscopic 1-anastomosis gastric bypass: surgical risk and long-term results

BACKGROUND

Laparoscopic 1- (single-) anastomosis gastric bypass (OAGB) was developed as a simplified technique of Roux-en-Y gastric bypass (RYGB), but super long-term data are lacking.

OBJECTIVES

To evaluate the risks and long-term results of OAGB over a period of 20 years.

SETTING

Tertiary teaching hospital.

METHODS

A total of 2223 patients underwent OAGB from 2001 to 2020; the mean age was 35.3 ± 11.4 years (range, 14-71 yr), 70.2% were female, and the mean body mass index was 40.2 ± 11.9 kg/m². All data were kept in a prospective bariatric database. Patients were divided into 4 groups, based on the 5-year period in which their surgery was performed, and a retrospective analysis was conducted.

RESULTS

The means for operating time, intraoperative blood loss, and length of hospital stay after OAGB were 131.9 ± 40.1 minutes, 38.5 ± 30.7 mL, and 4.5 ± 4.0 days, respectively. There were 27 patients (1.2%) with 30-day postoperative major complications overall, but the group rate decreased to .4% in the last 5-year period. At postoperative years 5, 10, and 15, the percentages of total weight loss were 31.9%, 29.6%, and 29.5%, respectively, and the percentages of excess weight loss were 77.2%, 68.4%, and 65.5%, respectively. Among 739 patients (33.2%) with type 2 diabetes (T2D), the rates of complete remission (glycated hemoglobin < 60%) at 5, 10, and 15 years were 67.3%, 73.8%, and 66.7%, respectively. The weight loss and antimetabolic effects were similar in each 5-year period, but a significant malnutrition effect was observed. A total of 113 (5.1%) patients needed revision surgery at follow-up, due to malnutrition (n = 51), weight regain (n = 24), acid or bile reflux (n = 22), marginal ulcer (n = 8), ileus (n = 3), and other causes (n = 5). At 15 years, the overall revision rate was 11.9% (27/226), and 80% of the patients were very satisfied with their procedures.

CONCLUSION

Our results showed that OAGB is a safe and durable primary bariatric procedure, with sustained weight loss and a high resolution of T2D up to 20 years post surgery in Taiwan, although malnutrition is a major side effect.

The Hardship of Recovering a Patient from Liver Failure after One Anastomosis Gastric Bypass

BACKGROUND

The one anastomosis gastric bypass (OAGB) was first described in 2001 as a safe and effective procedure that meets the criteria for the "ideal" weight loss operation. However, revisions for malnutrition and liver failure were reported.

CASE REPORT

We report a patient who was transferred to our institution with protein calorie malnutrition and liver failure after undergoing OAGB.

METHODS

A 42-year-old morbidly obese female patient underwent a laparoscopic sleeve gastrectomy (LSG) in 2012 followed by conversion to OAGB in 2018 for weight regain at another institution. Nine months after conversion, she was transferred to our institution with dehydration, vomiting, dysphagia, generalized edema, and steatorrhea (7 times/day). She had become wheelchair bound. On examination, there was gross edema, protein-calorie malnutrition, dermatitis, and muscle wasting. She had anemia (8 g/dl) reference range (11.5-15.5 g/dl), bilirubin (1.8 mg/dl) (0.2-1.2 mg/dl), hypoalbuminemia (1.4 g/dl) (3.5-5 g/dl), and elevated international normalized ratio (INR). The patient was admitted to the hospital and was started on total parenteral nutrition (TPN), with thiamine, vitamins, iron injections, and trace mineral replacement. Her course was complicated by multiple episodes of line sepsis and bacteremia. After 6 weeks, we succeeded in raising her albumin to 2.9 g/dl and proceeded with surgery.

TECHNIQUE

Laparoscopic exploration started with identifying the anatomy and measuring the biliopancreatic limb (BPL = 430 cm) and the common channel (CC = 380 cm). First, we restored the continuity of the small bowel. Then the long gastric pouch was trimmed. Finally, the patient was converted to a Roux-en-Y gastric bypass (RYGB) with a 30 cm BP limb and 70 cm Roux limb. The patient had an uneventful recovery and was discharged home on the fourth postoperative day. At 3 months of follow-up, her symptoms resolved, her laboratory work up normalized, and she regained mobility.

CONCLUSION

Malnutrition and liver failure after OAGB are not uncommon. It is encountered with configurations of longer BP limb. BPL length of 150 to 200 cm seems to reduce such complications. Preoperative nutritional optimization is key. Conversion to a proximal RYGB is a safe and feasible approach.

Omega Loop Gastroileal Bypass (OLGIBP/SAGI) Versus One Anastomosis Gastric Bypass (OAGB): Medium-Term Results

INTRODUCTION

In bariatric surgery, new surgical techniques are continually being developed. The one anastomosis gastric bypass (OAGB) has become increasingly common since 2001. However, some patients experience bile reflux or excessive weight loss. This study aimed to assess a new bariatric procedure designed to avoid some of the drawbacks of conventional OAGB.

MATERIAL AND METHODS

To lower the complication rate and pathophysiological impact after OAGB, we performed an omega loop gastroileal bypass (OLGIBP/SAGI) with a 300-cm common limb. We compared this technique with OAGB.

RESULTS

Seventeen patients underwent OLGIBP and 23 underwent OAGB. Mean operative time was 108 min for OLGIBP vs 103 min for OAGB. The mean hospital length of stay was 3 days (1 to 7). No complications related to the gastroenterostomy occurred. At 3 years, among OAGB patients, there were 5 (21.7%) cases of bile reflux including 2 (8.7%) requiring a revision to Roux-en-Y gastric bypass. Among OLGIBP patients, there were 3 (17.6%) cases of bile reflux 1 (5.9%) requiring a revision to Roux-en-Y gastric bypass. There was no albumin deficiency. At 3 years, % of total weight loss (TWL) was 43.6 + - 6.2 in the OAGB group vs 48.2 + - 7.4 in the OLGIBP group.

CONCLUSIONS

The bariatric and metabolic outcomes of OLGIBP are expected to be similar to those of OAGB. The OLGIBP technique should reduce the risks of malnutrition and bile reflux. The two techniques can be safely performed and offer alternatives in bariatric surgery.

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.