Measuring the small bowel length may decrease the incidence of malnutrition after laparoscopic one-anastomosis gastric bypass with tailored bypass limb

Pathological and immunohistochemical analysis of gastric mucosa after one anastomosis gastric bypass surgery

BACKGROUND

One anastomosis gastric bypass (OAGB) is now the third most common bariatric surgery worldwide. This procedure is garnering increasing attention, but its complication of bile reflux and the associated risk of gastric carcinogenesis remains controversial.

OBJECTIVE

The study aims to assess the impact of bile reflux on the gastric mucosa by comparing pathological and immunohistochemical results of gastric mucosa before and 2 years after OAGB surgery.

METHODS

This retrospective study analyzed gastric lesions observed in gastroscopy before and after OAGB surgery. Pathological examinations were conducted on mucosal samples from proximal, middle and distal part of stomach, with a particular focus on the expression of Ki-67, P53, and CDX2 in immunohistochemistry. Ki-67 indicates cellular proliferation, P53 is a tumor suppressor protein, and CDX2 is a marker for intestinal differentiation.

RESULTS

A total of 16 patients completed the follow-up. Regarding gastritis, presurgery nonerosive gastritis was found in two cases (12.5%), and postsurgery in six cases (37.5%). Erosive gastritis increased from one case (6.2%) presurgery to three cases (18.7%) postsurgery, totaling an increase from three to nine cases (p = .028). Bile reflux in the stomach increased from one case (6.2%) presurgery to three cases (18.7%) postsurgery. Most lesions in the proximal, middle, and distal part of stomach were relatively mild, with normal tissue states being predominant. Mild inflammation was found in all three areas, whereas moderate inflammation, intestinal metaplasia, and glandular atrophy were less common. No cases of severe inflammation were noted. The expression of gastric biomarkers CDX-2, Ki67, and P53 showed no significant statistical variation in different areas.

CONCLUSION

Bile reflux does occur after OAGB, but its incidence is not high. Based on the immunohistochemical and pathological results of the gastric mucosa 2 years post-OAGB, there seems to be no significant causal relationship between OAGB and oncogenic inflammation around the gastric tube.

Revision/Conversion Surgeries After One Anastomosis Gastric Bypass-An Experts' Modified Delphi Consensus

PURPOSE

There is a lack of evidence for treatment of some conditions including complication management, suboptimal initial weight loss, recurrent weight gain, or worsening of a significant obesity complication after one anastomosis gastric bypass (OAGB). This study was designed to respond to the existing lack of agreement and to provide a valuable resource for clinicians by employing an expert-modified Delphi consensus method.

METHODS

Forty-eight recognized bariatric surgeons from 28 countries participated in the modified Delphi consensus to vote on 64 statements in two rounds. An agreement/disagreement among ≥ 70.0% of the experts was regarded to indicate a consensus.

RESULTS

A consensus was achieved for 46 statements. For recurrent weight gain or worsening of a significant obesity complication after OAGB, more than 85% of experts reached a consensus that elongation of the biliopancreatic limb (BPL) is an acceptable option and the total bowel length measurement is mandatory during BPL elongation to preserve at least 300-400 cm of common channel limb length to avoid nutritional deficiencies. Also, more than 85% of experts reached a consensus on conversion to Roux-en-Y gastric bypass (RYGB) with or without pouch downsizing as an acceptable option for the treatment of persistent bile reflux after OAGB and recommend detecting and repairing any size of hiatal hernia during conversion to RYGB.

CONCLUSION

While the experts reached a consensus on several aspects regarding revision/conversion surgeries after OAGB, there are still lingering areas of disagreement. This highlights the importance of conducting further studies in the future to address these unresolved issues.

Technical Considerations in One Anastomosis Gastric Bypass-the Israeli Society of Metabolic and Bariatric Surgery Experience

BACKGROUND

One anastomosis gastric bypass (OAGB) is gaining popularity worldwide due to its safety and effectiveness. OAGB is the most commonly performed metabolic bariatric surgery (MBS) in Israel. Israel is the only country where OAGB is the most prevalent MBS. Our aim is to address OAGB technical aspects using a national survey completed by members of the Israeli Society of Metabolic and Bariatric Surgery (ISMBS).

MATERIALS AND METHODS

An online-survey composed of a 17-item-based questionnaire was sent to ISMBS members. All responses were collected and analyzed.

RESULTS

A total of 47/64 (73.4%) ISMBS members participated in the survey. Most surgeons (74.5%) had > 10 years of MBS experience, and most (61.7%) performed > 100 MBS/year. The majority (78.7%) perform OAGB as their most common procedure. Most surgeons fashion a 10-15-cm pouch and use a 36-Fr bougie, (57.4% and 38.3%). Regarding bowel length measurement, 70% use visual estimation and 10.6% routinely measure total small bowel length (TSBL). The most common reasons for creating a longer biliopancreatic limb (BPL) were high body mass index (BMI) and revisional surgery (83.3% and 66%, respectively). In a primary procedure of a patient with a BMI = 40, most (76.6%) would create a 150-200-cm BPL. In patients with a BMI > 50 or revisional cases, most (70.2% and 68.0%) would create a 175-225-cm BPL.

CONCLUSION

OAGB is the most prevalent MBS performed in Israel. This survey showed common preferences and variations among ISMBS members. Further studies are needed in order to standardize and build a consensus on OAGB technique.

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

OBJECTIVE

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prevention of malnutrition after one anastomosis gastric bypass: value of the common channel limb length

PURPOSE

Hypoalbuminemia and anemia are commonly observed indications for one anastomosis gastric bypass (OAGB) reversal and remain significant concerns following the procedure. Sufficient common channel limb length (CCLL) is crucial to minimize nutritional complications. However, limited literature exists regarding the impact of CCLL on OAGB outcomes. This study aimed to assess the effect of CCLL on weight loss and nutritional status in patients who underwent OAGB.

METHODS

A prospective cohort study was conducted from August 2021 to July 2022, involving 64 patients with a body mass index of 40-50 kg/m2. The standardized length of the biliopancreatic limb (BPLL) for all patients in this study was set at 175 cm. Additionally, the measurement of the common channel limb length (CCLL) was performed consistently by the same surgeon for all included patients.

RESULTS

The mean age and BMI of the patients were 39.91 ± 10.03 years and 43.13 ± 2.43 kg/m2, respectively, at the time of surgery. There was a statistically significant negative correlation between CCLL and percent total weight loss (%TWL) at the 12-month mark after OAGB (P = 0.02). Hypoalbuminemia was observed in one patient (1.6%), while anemia was present in 17 patients (26.6%) at the one-year follow-up. Statistical analysis revealed no significant difference in the incidence of anemia and hypoalbuminemia between patients with CCLL < 4 m and those with CCLL ≥ 4 m.

CONCLUSION

A CCLL of 4 m does not appear to completely prevent nutritional complications following OAGB. However, maintaining a CCLL of at least 4 m may be associated with a reduced risk of postoperative nutritional deficiencies.

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.

Sleeve gastrectomy with one anastomosis bipartition versus one anastomosis gastric bypass: A pilot study

BACKGROUND

One anastomosis gastric bypass (OAGB) is a new recognized metabolic surgery, but the problem that we cannot screen the excluded stomach is a troubling issue in China. The emergence of sleeve gastrectomy plus one anastomosis bipartition (SG + OAB) makes us see a hope to solve this problem.

OBJECTIVES

By comparing the efficacy of the two surgical methods, to evaluate whether SG + OAB surgery can solve the dilemma faced by OAGB that the excluded stomach cannot be screened.

METHODS

A retrospective study to compare the patients who underwent OAGB and SG + OAB was conducted. The main outcome measures were (1) operation risk, (2) weight loss, and (3) diabetes remission at 6 months.

RESULTS

This study was conducted in the bariatric/metabolic surgical center. From November 2021 to February 2022, a total of 30 patients with obesity who received SG + OAB surgery were recruited. Another matched 60 patients undergoing OAGB were recruited as control group. There was no difference in preoperative age (32.15 ± 9.02 vs. 34.47 ± 7.22; p = .224), female ratio (83% vs. 85%; p = .837), and BMI (36.18 ± 5.30 vs. 34.68 ± 5.58; p = .217) between the two groups. OAGB had a shorter mean operation time (121.67 ± 20.41 vs. 143.50 ± 25.07 min; p < .001) and a lower intraoperative blood loss (21.92 ± 12.35 vs. 32.43 ± 22.01 mL; p = .005), but a longer postoperative flatus passage (2.13 ± 0.43 vs. 1.87 ± 0.43 days; p = .007) compared with the SG + OAB group. Two patients (6.7%) developed major surgical complication in SG + OAB group but no major complication developed in OAGB group. At 6 months after surgery, SG + OAB had a higher %total weight loss than OAGB (31.05 ± 3.12 vs. 28.14 ± 5.43%; p = .015), but diabetes remission rate was similarly high in both groups.

CONCLUSIONS

SG + OAB operation had a non-inferior or even better weight loss than OAGB, with a similar glycemic control efficacy. However, the high complication rate of SG + OAB is the major drawback that needs attention.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Safety and efficacy of OAGB/MGB during the learning curve: setting a benchmark in a bariatric center of excellence

Very little has been published on the learning curve (LC) of the One Anastomosis /Mini Gastric Bypass (OAGB/MGB). Aim of this study was to compare perioperative outcomes of OABG/MGBs performed during the LC of an experienced laparoscopic surgeon to global benchmark cut-offs. First 200 patients undergoing OAGB/MGB at our university hospital from 2010 to 2016 were retrospectively included in this study. LC of the surgeon was divided in two groups of 100 consecutive patients each and perioperative outcomes were compared to abovementioned global benchmarks for LSG and RYGB. A cumulative sum (CUSUM) analysis was performed for operative time and hospital stay. Uneventful postoperative recovery was recorded in 95% of patients. All benchmark values for RYGB were met in group 2. Comparison with cut-offs for LSG showed longer hospital stay and operative time in both groups but postoperative rate of complications resulted lower even for Group 1. CUSUM graph of the operative time runs randomly above the predetermined limit till the 40th cases but reaches the plateau after the 115th operation. CUSUM curve of the hospital stay reaches the plateau after the 57th case. OAGB/MGB confirms to be a feasible procedure, which can be safely and effectively performed during the learning curve. However, at least 100 hundred cases are required to reduce operative time and hospital stay.

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

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

Weight loss outcomes for patients undergoing conversion to Roux-en-Y-gastric bypass after sleeve gastrectomy

BACKGROUND

Despite excellent reported outcomes after laparoscopic sleeve gastrectomy (LSG), a percentage of patients go on to have a secondary bariatric surgery to manage side-effects or address weight regain after LSG. Reported weight loss outcomes for patients undergoing laparoscopic Roux-en-Y gastric bypass (LRYGB) after previous LSG are variable. We sought to determine the weight-loss outcomes of patients undergoing LRYGB after LSG in the largest bariatric surgical network in Canada and to determine whether outcomes differ according to indications for conversion.

METHODS

The Bariatric Registry is a multi-center database with prospectively collected standardized data on patients undergoing bariatric surgery at ten Bariatric Centers of Excellence within the Ontario Bariatric Network in Ontario, Canada. A retrospective analysis was performed of patients who underwent LRYGB after previous LSG between 2012 and 2019. Weight loss outcomes were compared between patients who underwent LRYGB for insufficient weight loss/weight regain and those who underwent conversion to LRYGB for other reasons.

RESULTS

Excluding patients with multiple revisions and those without follow-up data, 48 patients were included in the analysis: 33 patients (69%) underwent conversion to LRGYB for insufficient weight loss/weight regain (Group 1) and 15 patients (31%) underwent conversion for other reasons (Group 2). Mean body mass index (BMI) measured pre-LSG, pre-LRYGB, and at mid-term follow-up after LRYGB was 61, 48, and 43 kg/m² in Group 1 and 51, 39, and 34 kg/m² in Group 2, respectively. ΔBMI and %total weight loss (TWL) at mid-term follow-up were not significantly different between the groups.

CONCLUSIONS

Conversion to LRYGB after previous LSG resulted in an additional loss of 4 kg/m² in BMI points at mid-term follow-up. Patients lost a similar number of BMI points and cumulative %TWL was similar regardless of reason for conversion. This can help inform surgical decision-making in the setting of weight regain after LSG.

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.

One anastomosis gastric bypass as a one-stage bariatric surgical procedure in patients with BMI ≥ 50 kg/m2

In patients with BMI ≥ 50 kg/m2, it is difficult to select an appropriate procedure that can lead to optimum results. This study aims to evaluate mid-term weight loss outcomes in patients with BMI ≥ 50 kg/m2 following one anastomosis gastric bypass (OAGB) as a one-stage procedure. A prospective study was conducted on patients with BMI ≥ 50 kg/m2, aged 18 years and above who had undergone primary OAGB from January 2016 to February 2019 with at least two years follow-ups. A total of 197 patients with BMI ≥ 50 kg/m2 had underwent OAGB. The mean age was 38 years and the mean pre-operative BMI was 53.7 kg/m2. Mean EWL% were 63.7%, 67.8% and 66.2% at one, two and five years after OAGB respectively. The highest level of EWL% was 68.4%, which was achieved in the 18th month following OAGB. OAGB can be performed safely in patients with BMI ≥ 50 kg/m2 as a one-stage procedure with acceptable weight loss outcomes and remission of obesity associated medical problems.

Tailoring limb length based on total small bowel length in one anastomosis gastric bypass surgery (TAILOR study): study protocol for a randomized controlled trial

Background

The one anastomosis gastric bypass (OAGB) is being performed by an increasing number of bariatric centers over the world. However, the optimal length of the biliopancreatic (BP) limb remains a topic of discussion. Retrospective studies suggest the benefit of tailoring BP-limb length; however, randomized trials are lacking. The aim of this study is to investigate whether tailoring the length of the BP-limb based on total small bowel length (TSBL) leads to better results in terms of weight loss, vitamin deficiencies, and bowel movements compared to a fixed BP-limb length.

Methods

The TAILOR study is a double-blind single-center randomized controlled trial. Patients scheduled for primary OAGB surgery will be randomly allocated either to a standard BP-limb of 150 cm or to a BP-limb length based on their TSBL: TSBL < 500 cm, BP-limb 150 cm; TSBL 500–700 cm, BP-limb 180 cm; TSBL > 700 cm, BP-limb 210 cm. The primary outcome is to compare the percent total weight loss (%TWL) at 5 years between the two groups. Secondary outcomes include nutritional deficiencies, remission of comorbidities, symptoms of dumping, quality of life, and daily bowel movements. The study includes a total of 212 patients and is designed to detect a 5% difference in the primary endpoint.

Discussion

The TAILOR study will provide new insights into the effect of different BP-limb lengths and the role of the TSBL in the OAGB. The study is designed to provide guidance for bariatric surgeons to determine the optimal BP-limb length in the OAGB.

Trial registration

Dutch Trial Register NL7945. Prospectively registered on 08 September 2019. NTR (trialregister.nl)

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06456-w.

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.

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.

Is One Anastomosis Gastric Bypass with a Biliopancreatic Limb of 150 cm Effective in the Treatment of People with Severe Obesity with BMI > 50?

Purpose

The treatment of people with severe obesity and BMI > 50 kg/m² is challenging. The present study aims to evaluate the short and mid-term outcomes of one anastomosis gastric bypass (OAGB) with a biliopancreatic limb of 150 cm as a primary bariatric procedure to treat those people in a referral center for bariatric surgery.

Material and Methods

Data of patients who underwent OAGB for severe obesity with BMI > 50 kg/m² between 2010 and 2017 were collected prospectively and analyzed retrospectively. Follow-up comprised clinical and biochemical assessment at 1, 3, 6, 12, 18, and 24 months postoperatively, and once a year thereafter.

Results

Overall, 245 patients underwent OAGB. Postoperative mortality was null, and early morbidity was observed in 14 (5.7%) patients. At 24 months, the percentage total weight loss (%TWL) was 43.2 ± 9, and percentage excess weight loss (%EWL) was 80 ± 15.7 (184 patients). At 60 months, %TWL was 41.9 ± 10.2, and %EWL was 78.1 ± 18.3 (79 patients). Conversion to Roux-en-Y gastric bypass was needed in three (1.2%) patients for reflux resistant to medical treatment. Six patients (2.4%) had reoperation for an internal hernia during follow-up. Anastomotic ulcers occurred in three (1.2%) patients. Only two patients (0.8%) underwent a second bariatric surgery for insufficient weight loss.

Conclusion

OAGB with a biliopancreatic limb of 150 cm is feasible and associated with sustained weight loss in the treatment of severe obesity with BMI > 50 kg/m². Further randomized studies are needed to compare OAGB with other bariatric procedures in this setting.

Graphical abstract

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.

One Anastomosis Gastric Bypass Performed with a 150-cm Biliopancreatic Limb Delivers Weight Loss Outcomes Similar to Those with a 200-cm Biliopancreatic Limb at 18 -24 Months

BACKGROUND

It has been suggested that shortening the biliopancreatic limb (BPL) length with one anastomosis gastric bypass (OAGB) to 150 cm would reduce the revision rates for malnutrition. But, it remains unclear if this would not compromise the efficacy of this procedure.

METHODS

We examined our prospectively maintained database to compare the outcomes of patients who had their OAGB performed with a 150-cm BPL with those performed with a 200-cm BPL.

RESULTS

Medium-term weight loss data at 18-24 months was available for 343/398 (86.1% follow-up) patients. Of these, 225 had undergone OAGB-200 and 118 had undergone OAGB-150. The mean preoperative weight and body mass index were 141.6 ± 32.8 kg and 49.76 ± 8.6 kg/m², respectively, in the OAGB-200 group compared with 133.7 ± 24.5 kg and 47.83 ± 7.2 kg/m², respectively, in the OAGB-150 group. There was no significant difference in albumin and haemoglobin levels in the two groups at 18-month follow-up. The mean excess weight loss was 75.0% ± 20.1 in the OAGB-200 group and 74.0% ± 22.0 in the OAGB-150 group (p = 0.6714). A total of 89.7% (n = 202) patients achieved an excess weight loss (EWL) of ≥ 50.0% in the OAGB-200 group compared with 85.5% (n = 103) in the OAGB-150 group (p value = 0.4754). The mean total weight loss was 36.1% ± 9.2 in the OAGB-200 group compared with 34.0% ± 9.8 in the OAGB-150 group (p value = 0.0598).

CONCLUSIONS

OAGB performed with a BPL of 150 cm delivers weight loss outcomes similar to that seen with a BPL of 200 cm.

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.

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.

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 Gastric Bypass for the Treatment of Type 2 Diabetes: Long-Term Results and Recurrence

BACKGROUND

Bariatric/metabolic surgery has been incorporated into the therapeutic treatment of type 2 diabetes mellitus (T2DM). Among many bariatric/metabolic procedures, one anastomosis gastric bypass (OAGB) is one of the most effective procedures but long-term data about T2DM recurrence after OAGB are lacking.

METHODS

Outcomes of 134 patients who had undergone OAGB for the treatment of T2DM with long-term (5 years) follow-up were assessed in a retrospective cohort study. The remission of T2DM after OAGB surgery was evaluated in different groups using a scoring system composed of the age, BMI, C-peptide level, duration of T2DM (ABCD score), and percent of total weight loss (%TWL).

RESULTS

The %TWL and percent of excess weight loss (%EWL) of the OAGB patients at 5 years after surgery were 29.2 (10.6) and 72.1(27.5), respectively. The mean BMI decreased from 39.5(7.9) to 27.6(5.3) kg/m² and mean glycated hemoglobin A1C (HbA1c) decreased from 8.9 to 5.9% in OAGB patients at 5 years after OAGB. The complete T2DM remission rate of OAGB was 76.1% at 1 year and 64.2% at 5 years after surgery. Forty-one (57.8%) out of 71 patients who completed a 10-year follow-up remained in complete T2DM remission. The T2DM recurrence rate of OAGB patients was 15.7% at 5 years after surgery.

CONCLUSIONS

OAGB is highly effective in inducing T2DM remission but a significant number of patients will still have T2DM recurrence. To select patient with an ABCD score > 5 and maintaining a weight loss greater than 30% is important for durable T2DM remission after OAGB.