Laparoscopic One-Anastomosis Gastric Bypass: Technique, Results, and Long-Term Follow-Up in 1200 Patients

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.

Revisional Surgery of One Anastomosis Gastric Bypass for Severe Protein–Energy Malnutrition

Background: One anastomosis gastric bypass (OAGB) is safe and effective. Its strong malabsorptive component might cause severe protein–energy malnutrition (PEM), necessitating revisional surgery. We aimed to evaluate the safety and outcomes of OAGB revision for severe PEM. Methods: This was a single-center retrospective analysis of OAGB patients undergoing revision for severe PEM (2015–2021). Perioperative data and outcomes were retrieved. Results: Ten patients underwent revision for severe PEM. Our center’s incidence is 0.63% (9/1425 OAGB). All patients were symptomatic. Median (interquartile range) EWL and lowest albumin were 103.7% (range 57.6, 114) and 24 g/dL (range 19, 27), respectively, and 8/10 patients had significant micronutrient deficiencies. Before revision, nutritional optimization was undertaken. Median OAGB to revision interval was 18.4 months (range 15.7, 27.8). Median BPL length was 200 cm (range 177, 227). Reversal (n = 5), BPL shortening (n = 3), and conversion to Roux-en-Y gastric bypass (RYGB) (n = 2) were performed. One patient had anastomotic leak after BPL shortening. No death occurred. Median BMI and albumin increased from 22.4 kg/m² (range 20.6, 30.3) and 35.5 g/dL (range 29.2, 41), respectively, at revision to 27.5 (range 22.2, 32.4) kg/m² and 39.5 g/dL (range 37.2, 41.7), respectively, at follow-up (median 25.4 months, range 3.1, 45). Complete resolution occurs after conversion to RYGB or reversal to normal anatomy, but not after BPL shortening. Conclusions: Revisional surgery of OAGB for severe PEM is feasible and safe after nutritional optimization. Our results suggest that the type of revision may be an important factor for PEM resolution. Comparative studies are needed to define the role of each revisional option.

Adjustable Gastric Banding Conversion to One Anastomosis Gastric Bypass: Data Analysis of a Multicenter Database

INTRODUCTION

One anastomosis gastric bypass (OAGB) has been proposed as a rescue technique for laparoscopic adjustable gastric banding (LAGB) poor responders.

AIM

We sought to analyze, complications, mortality, and medium-term weight loss results after LAGB conversion to OAGB.

METHODS

Data analysis of an international multicenter database.

RESULTS

One hundred eighty-nine LAGB-to-OAGB operations were retrospectively analyzed. Eighty-seven (46.0%) were converted in one stage. Patients operated on in two stages had a higher preoperative body mass index (BMI) (37.9 vs. 41.3 kg/m², p = 0.0007) and were more likely to have encountered technical complications, such as slippage or erosions (36% vs. 78%, p < 0.0001). Postoperative complications occurred in 4.8% of the patients (4.6% and 4.9% in the one-stage and the two-stage group, respectively). Leak rate, bleeding episodes, and mortality were 2.6%, 0.5%, and 0.5%, respectively. The final BMI was 30.2 at a mean follow-up of 31.4 months. Follow-up at 1, 3, and 5 years was 100%, 88%, and 70%, respectively.

CONCLUSION

Conversion from LAGB to OAGB is safe and effective. The one-stage approach appears to be the preferred option in non-complicate cases, while the two-step approach is mostly done for more complicated cases.

Single anastomosis sleeve jejunal (SAS-J) bypass as a treatment for morbid obesity, technique and review of 1986 cases and 6 Years follow-up. Retrospective cohort

BACKGROUND

Santoro's operation is a sleeve gastrectomy with transit bipartition. The operation aims to maintain passage to the duodenum to minimize nutritional deficiency. This procedure is rapidly changed to single anastomosis sleeve ileal (SASI) bypass. SAS-J bypass is a modification of SASI with a short biliary limb.

MATERIAL AND METHODS

This study is a retrospective study of prospectively collected data. The study includes a comprehensive review of 1986 patients who underwent SAS-J bypass over 6 years. The total number is used to evaluate the perioperative data. One- and two-year follow-up was used to evaluate weight loss and comorbidities; follow-up of more than 5 years was used to obtain long-term results.

RESULTS

In this study, 70.4% of patients were female and 29.6% were male. The mean body mass index (BMI) was 44.7. The mean age was 42 years. Regarding comorbidities, 25.8% of the patients had type 2 diabetes, 31% were hypertensive, 14.2% had sleep apnea syndrome, 6.6% had gastroesophageal reflux disease (GERD), and 39.6% had hyperlipidemia. Of the 1294 patients who complete one-year follow up, %EWL reached 87%. Blood glucose levels were normalized in 98.5% of patients, hypertension remitted in 93%, hyperlipidemia improved in 97%, SAS is improved in all cases, and GERD improved in 89% of patients. After 5 years, 94 patients' BMI decreased from 44.3 to 28.3 without significant nutritional deficiency.

CONCLUSIONS

Laparoscopic SAS-J bypass is an effective and simple alternative bariatric procedure at short- and long-term follow-up.

Generation and characterization of a mouse model for one anastomosis gastric bypass surgery

One anastomosis gastric bypass (OAGB) surgery became a common bariatric procedure in recent years. In this surgery, the distal stomach, duodenum, and proximal jejunum are bypassed, leading to weight loss, improvement in metabolic parameters, and a change in hormonal secretion. We sought to generate and characterize a mouse model for OAGB. Mice fed for 26 wk on a high-fat diet were assigned to OAGB, sham surgery, or caloric restriction and were followed for 50 more days on a high-fat diet. Physiological and histological parameters of the mice were compared during and at the end of the experiment. OAGB-operated mice lost weight and displayed low levels of plasma lipids, high insulin sensitivity, and rapid glucose metabolism compared with sham-operated mice. OAGB-operated mice had higher energy expenditure, higher levels of glucagon-like peptide (GLP-1), and lower albumin than weight-matched calorie-restricted mice. There was no difference in the histology of the endocrine pancreas. The livers of OAGB mice had little hepatic steatosis yet presented with a large number of phagocytic cells. The OAGB mouse model recapitulates many of the phenotypes described in patients that underwent OAGB and enables molecular and physiological studies on the outcome of this surgery.NEW & NOTEWORTHY A mouse model for one anastomosis gastric bypass (OAGB) surgery displays similar outcomes to clinical reports and enables to study the weight loss-dependent and -independent effects of this bariatric surgery.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Outcomes and Effects of 250-cm Biliopancreatic Limb One Anastomosis Gastric Bypass in Patients with BMI > 50 kg/m2 with Total Bowel Length > 6 m: a 2-Year Follow-up

Background

There is a controversy on the suitable bariatric procedure for patients with BMI > 50 kg/m². Many surgeons prefer the Roux en-Y gastric bypass (RYGB) while others resort to long biliopancreatic limb (BPL) one anastomosis gastric bypass (OAGB).

Methods

This study included patients with BMI > 50 kg/m² who underwent 250-cm BPL OAGB with total bowel length (TBL) > 6 m and completed 24-month follow-up from July 2015 to November 2021. Demographic data with preoperative weight, BMI, hypertension (HTN), DM (HbA1C), Hb, iron, calcium, albumin, vitamin D, and parathormone levels (PTH) were recorded. Operative time, total bowel length (TBL), residual length (RBL), complications and postoperative weight, BMI, % of total weight loss (%TWL), HTN, DM, and alkaline reflux as well as Hb, iron, calcium, albumin, vitamin D, and PTH levels were recorded at 6, 12, 18, and 24 months.

Results

OAGB had a significant decrease in weight, BMI (25.6 ± 3.4 kg/m² at 24 months) with %TWL of 48 ± 5% at 24 months. TBL and RBL were 6.7 ± 0.65 and 4.2 ± 0.65 m respectively. %BL (RBL/TBL*100) was 62.4 ± 3.3%. The HbA1C, HTN, and alkaline reflux incidence were 5.5 ± 0.29 gm%, 1.4%, and 3.7% respectively at 24 months. Hb, iron, calcium, albumin, and vitamin D showed a significant decrease but still within normal range, and PTH showed a significant increase at 24 months.

Conclusion

Long BP (250 cm) OAGB in patients with BMI > 50 kg/m² with TWL > 6 m had good results in the achievement of weight loss and weight maintenance goals with remission of associated comorbidities as HTN and DM.

Graphical abstract

Gastrointestinal Quality of Life in Morbidly Obese Patients Undergoing One Anastomosis Gastric Bypass (OAGB): Derivation of a "Mini GIQLI" Score

BACKGROUND

One anastomosis gastric bypass (OAGB) is now one of the mainstream bariatric surgical procedures with proven safety and efficacy. However, data on the gastrointestinal quality of life following OAGB is lacking.

METHODS

This is a retrospective analysis of a prospectively collected database, performed at a single tertiary care teaching hospital from January 2016 until March 2021. All patients undertook the Gastrointestinal Quality of Life Index (GIQLI) questionnaire. GIQLI was correlated with various parameters. Principal component analysis (PCA) was used to assess the importance of each question in the questionnaire and devise a "Mini GIQLI score".

RESULTS

A total of 60 patients were included. The %TWL at 3 and 5 years was 26.2 ± 11.9%, 31.7 ± 11 respectively. The mean weight regain was 5.6 ± 8.5 kg. The mean GIQLI score was 125 ± 13.1. The mean scores for questions pertaining to gastrointestinal, social, psychological, and physical domains were 3.49, 3.7, 3.45, and 3.27 respectively. Scree plot of principal component analysis showed that a new score ("Mini GIQLI") combining only 5 questions had good correlation with the overall GIQOL score (r = 0.842). The five questions related to anxiety, fatigue, feeling unwell, loss of endurance, and feeling unfit.

CONCLUSIONS

Patients report a good score on GIQLI assessment following OAGB. The Mini GIQLI score is a quicker tool with good correlation to the full-length GIQLI score.

A laparoscopic one anastomosis gastric bypass with wrapping versus nonwrapping fundus of the excluded part of the stomach to treat obese patients (FundoRingOAGB trial): study protocol for a randomized controlled trial

BACKGROUND

Laparoscopic one anastomosis gastric bypass (LOAGB) is a simple variation of gastric bypass and has gained worldwide popularity with clinical outcomes similar to laparoscopic Roux-en-Y gastric bypass (LRYGB) for weight loss and management of comorbidities. However, biliary reflux to the esophagus negates the benefits of LOAGB. In addition, weight gain after LOAGB and after LRYGB is a major problem in bariatric surgery. The aim of this article is to describe the design and protocol of a randomized controlled trial comparing the outcomes of two methods of LOAGB: experimental method with wrapping versus standard method nonwrapping fundus of the excluded part of the stomach to prevent weight regain and biliary reflux after LOAGB.

METHODS

The study was designed as a single-center prospective, interventional, randomized controlled trial. Masking: None (open label). Allocation: randomized. Enrollment: 100 obese patients. The relevant ethics committee approved the trial protocol. The endpoints (body mass index, bile reflux in the esophagus, other reflux symptoms) will be assessed presurgery and postsurgery (12, 24, and 36 months postoperatively).

DISCUSSION

With its 3-year follow-up time, this RCT will provide important data on the impact of wrapping the fundus of the excluded part of the stomach to prevent weight regain and biliary reflux after LOAGB.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04834635 . Registered on 8 April 2021.

A laparoscopic one anastomosis gastric bypass with wrapping versus nonwrapping fundus of the excluded part of the stomach to treat obese patients (FundoRingOAGB trial): study protocol for a randomized controlled trial

Background

Laparoscopic one anastomosis gastric bypass (LOAGB) is a simple variation of gastric bypass and has gained worldwide popularity with clinical outcomes similar to laparoscopic Roux-en-Y gastric bypass (LRYGB) for weight loss and management of comorbidities. However, biliary reflux to the esophagus negates the benefits of LOAGB. In addition, weight gain after LOAGB and after LRYGB is a major problem in bariatric surgery.

The aim of this article is to describe the design and protocol of a randomized controlled trial comparing the outcomes of two methods of LOAGB: experimental method with wrapping versus standard method nonwrapping fundus of the excluded part of the stomach to prevent weight regain and biliary reflux after LOAGB.

Methods

The study was designed as a single-center prospective, interventional, randomized controlled trial. Masking: None (open label). Allocation: randomized. Enrollment: 100 obese patients. The relevant ethics committee approved the trial protocol.

The endpoints (body mass index, bile reflux in the esophagus, other reflux symptoms) will be assessed presurgery and postsurgery (12, 24, and 36 months postoperatively).

Discussion

With its 3-year follow-up time, this RCT will provide important data on the impact of wrapping the fundus of the excluded part of the stomach to prevent weight regain and biliary reflux after LOAGB.

Trial registration

ClinicalTrials.govNCT04834635. Registered on 8 April 2021.

Safety and Efficacy of One Anastomosis Gastric Bypass on Patients with Severe Obesity Aged 65 Years and Above

PURPOSE

With the global increase in life expectancy and the subsequent impaired quality of life in older obese adults, modalities such as bariatric surgery become crucial to help lose excess weight. This study was conducted to evaluate the effectiveness and safety of one anastomosis gastric bypass (OAGB) in patients 65 years old and above.

MATERIALS AND METHODS

This retrospective cohort study was conducted on 61 patients with severe obesity aged ≥ 65 years through Iran National Obesity Surgery Database. The patients had undergone OAGB and were followed up for 12 to 60 months. The required data was extracted through national database.

RESULTS

Mean age and BMI of the patients were 67.62 ± 2.03 years and 46.42 ± 5.46 kg/m², respectively. Regarding gender, 90.1% of the participants were female. Mean operative time and length of hospital stay were 41.37 ± 13.91 min and 1.16 ± 0.61 days, respectively. Five patients (8.19%) required ICU admission. The changes in %TWL after 3, 6, 12, 24, 36, 48, and 60 month follow-up was 18.62%, 25.51%, 32.84%, 35.86%, 38.49%, 31.41%, and 29.52%, respectively. The resolution of gastroesophageal reflux disease, diabetes mellitus, dyslipidemia, obstructive sleep apnea, and hypertension after 24 month was about 100%, 65%, 73.33%, 100%, and 76%, respectively. The postoperative early and late complications were 6.53% and 11.46%, respectively. We did not find significant difference in above results between two age groups of 65-70 and > 70 years.

CONCLUSIONS

OAGB can be a good choice in older obese adults because of its shorter operative time, higher potency, and low complication rate.

Roux-en-Y gastric bypass, sleeve gastrectomy, or one-anastomosis gastric bypass? A systematic review and meta-analysis of randomized-controlled trials

OBJECTIVE

This study aimed to determine which bariatric procedure allows patients to obtain the best weight-loss outcomes and a remission of type 2 diabetes.

METHODS

Databases were searched for randomized-controlled trials comparing Roux-en-Y gastric bypass (RYGB) with sleeve gastrectomy (SG) or one-anastomosis gastric bypass (OAGB). The mean difference (MD) or the relative risk was determined.

RESULTS

Twenty-five randomized-controlled trials were analyzed. Excess weight loss (EWL, percentage) was greater for RYGB patients at 3 years (MD: 11.93, p < 0.00001) and 5 years (MD: 13.11, p = 0.0004). Higher excess BMI loss (percentage) was found in RYGB at 1 year (MD: 11.66, p = 0.01). Total weight loss (percentage) was greater for RYGB patients after 3 months (MD: 2.41, p = 0.02), 6 months (MD: 3.83, p < 0.00001), 1 year (MD: 6.35, p < 0.00001), and 5 years (MD: 3.90, p = 0.005). No difference in terms of remission of type 2 diabetes was seen between RYGB and SG. EWL was significantly more important after OAGB than after RYGB after 1 year (MD: -10.82, p = 0.003).

CONCLUSIONS

RYGB is more efficient than SG in the midterm. OAGB offers greater EWL than RYGB after 1 year, but further evidence is needed to confirm this result.

Conversion of One Anastomosis Gastric Bypass to Roux-en-Y Gastric Bypass: Results of a Retrospective Multicenter Study

BACKGROUND

One anastomosis gastric bypass (OAGB) may expose the patient to certain specific complications. Here, we report the results of conversion of OAGB to Roux-en-Y gastric bypass (RYGB) in terms of outcomes and weight loss.

METHODS

Between January 2009 and January 2019, all patients undergoing conversion of OAGB to RYGB because of complications due to OAGB (n = 23) were included. The primary efficacy endpoint was the effectiveness of converting OAGB to RYGB. The secondary endpoints were overall mortality and morbidity during the first 3 postoperative months, specific morbidity, reoperation, length of hospitalization, weight loss, and progression of comorbidities related to obesity at 2-year follow-up.

RESULTS

Indications for conversion were bile reflux (n = 14; 60.9%), severe malnutrition (n = 3; 13%), gastro-gastric fistula (n = 4; 17.4%), and anastomotic leak (n = 2; 8.7%). The median time interval between OAGB and conversion to RYGB was 34 months (0-158). At the time of RYGB, median body mass index (BMI) was 28.0 kg/m² (18.2-50.7), representing a median BMI change of 14.0 (- 1.7-43.5). Fifteen surgeries (65.1%) were completed laparoscopically. Five complications (21.7%) were recorded, including 2 major ones (8.7%). Reoperation rate was 4.3% (n = 1). At 24 months of follow-up (n = 18; 78.3%), median BMI was 28.7 kg/m² (19.4-35.4), representing a median BMI change of 19.5 (12.2-43.1). No patient complained of bile reflux or persistent malnutrition.

CONCLUSION

RYGB performed as revisional surgery for complications after OAGB is an effective procedure with no major weight regain at 2 years of follow-up.

Recent Technical Developments in the Field of Laparoscopic Surgery: A Literature Review

The benefits of laparoscopic surgery (LS) include a speedy recovery, shorter duration of hospital stay, minimal postoperative pain, discomfort and disabilities, and better cosmetic outcomes (less scarring) that help an individual to resume normal daily activities and return to work. A comprehensive literature search on laparoscopic surgeries was conducted using different Internet-based search engines and databases from August 2021 to October 2021. The search was limited to articles published in the English language and those published between years 2005 and 2021. A total of 126 articles were initially identified. Two independent reviewers thoroughly examined the quality and content of the articles. Articles with duplicate data were excluded, and the remaining articles were screened and assessed by the titles and abstracts. After a vigorous assessment, we included data from 49 articles for this review process. Bibliographic management was done using the software “EndNote” (Thomson Reuters, New York, NY, USA).

It was concluded that LS has become the technique of choice for virtually every kind of abdominal surgery, evident by numerous scholarly publications in this field. Level I evidence demonstrating the advantage of LS over open surgery has been reported for numerous operations, including fundoplication for gastroesophageal regurgitation disease, bariatric surgery for weight loss, and cancer resection. Advanced LS has subsequently been expanded to include hepatectomy, pancreatectomy, urology, and gynecology. Patients who are at risk of having elevated abdominal pressure during LS, however, should proceed with care. Recent advances in natural orifice transluminal endoscopic surgery, single-incision laparoscopic surgery, and robot-assisted laparoscopic surgery are promising.

Short-Term Changes on Body Composition After Sleeve Gastrectomy and One Anastomosis Gastric Bypass

Introduction: Changes in body composition after different bariatric surgeries have been studied extensively, but most of them have emphasized on Roux-en-Y gastric bypass. Only a few studies have assessed the effects of sleeve gastrectomy (SG). Also, the effect of one anastomosis gastric bypass (OAGB) on body composition is not fully apprehended. Furthermore, there is no agreement on how much fat-free mass (FFM) loss is tolerable in weight loss interventions. Therefore, we decided to assess the reduction in fat mass (FM) and FFM at 1, 3, 6, and 12 months after two types of bariatric surgery in a single center. Methods: In the current retrospective cross-sectional study, the patients' hospital records were analyzed. We included patients who had SG or OAGB and a complete 1-year follow-up record. We recorded demographic data as well as weight, body mass index (BMI), FM, and FFM before and at 1, 3, 6, and 12 months after surgery in a predesigned checklist. Results: We analyzed 311 patients (43 males and 268 females) in the SG (N = 192, 61.7%) and OAGB (N = 119, 38.3%) groups. Both the SG and OAGB groups demonstrated a statistically significant reduction in weight, BMI, FM, and FFM indices at 12 months after the intervention (P < .001). Moreover, no statistically significant difference was observed between the SG and OAGB groups regarding the mean of all body composition indices at 3, 6, and 12 months after the intervention. Conclusion: We found that SG and OAGB effectively decreased weight and body composition indices, comprising FM and FFM, with no significant difference between each other.

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.

Revisional One Anastomosis Gastric Bypass with a 150-cm Biliopancreatic Limb After Failure of Adjustable Gastric Banding: Mid-Term Outcomes and Comparison Between One- and Two-Stage Approaches

PURPOSE

Laparoscopic adjustable gastric banding (LAGB) was a common procedure worldwide but associated with a high rate of long-term failure. This study aims to evaluate the safety and effectiveness of conversion to one anastomosis gastric bypass (OAGB) after failed LAGB.

MATERIALS AND METHODS

We undertook a retrospective analysis of a prospectively maintained database in a tertiary referral center for bariatric surgery. All cases of revisional OAGB with a biliopancreatic limb (BPL) of 150 cm after failed LAGB performed between 2010 and 2016 were analyzed.

RESULTS

Overall, 215 patients underwent conversion from LAGB to OAGB. Indication for surgery was primary weight loss (WL) failure in 30.7% of cases and long-term complications in the remaining patients, with or without associated weight regain. At the time of OAGB, the mean age was 43.2 ± 10.5 years and the mean BMI was 42 ± 6.9. Overall postoperative morbidity was 13.5%. The postoperative abscess ± leak rate was 5.9% in the overall population. Two years after OAGB, 9.7% of patients were lost to follow-up, % excess weight loss (EWL) was 88.2 ± 23.9, and % total weight loss (TWL) was 38.7 ± 9.3. At 5 years, 16.6% of patients were lost to follow-up, %EWL was 82.4 ± 25, and %TWL was 36.1 ± 10. There was no statistical difference in complication rates or WL results between the one-stage and two-stage approaches.

CONCLUSION

OAGB with a 150-cm BPL represents a safe and effective option after failed LAGB. Both synchronous OAGB and two-step revisional OAGB guarantee satisfying results in terms of postoperative morbidity and WL outcomes.

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.

10-year weight loss outcomes after Roux-en-Y gastric bypass and attendance at follow-up visits: a single-center study

BACKGROUND

Long-term durability of weight loss is a prerequisite for a greater acceptance of bariatric surgery.

OBJECTIVES

To examine long-term weight trajectory in patients undergoing Roux-en-Y gastric bypass (RYGB) and determine factors predicting long-term follow-up and weight outcomes.

SETTING

University hospital.

METHODS

A retrospective cohort of adults who underwent RYGB during 1997-2010 were identified and followed until 2017. Predictors for attendance at periodic follow-up visits, reduction in body mass index (BMI), and percent excess BMI lost were determined using multivariable logistic regression and linear mixed-effects models. The latter was used to predict long-term weight outcomes for a typical patient.

RESULTS

The study included 1104 patients with a mean age of 45.5 (standard deviation [SD] 9.9) years and a preoperative BMI of 54.7 (SD 10.9) kg/m². Follow-up data were available for 92.8% of the patients after 1 year, 50.0% after 5 years, and 35.2% after 10 years post-surgery. Black patients, compared with White patients, were less likely to attend follow-up visits. Attendance at follow-up visits at least every other year was not associated with larger weight loss, but higher preoperative BMI, being White (versus Black), and female sex were. Predicted BMI reduction for a typical patient, a 45-year-old White female with a preoperative BMI of 54.7 kg/m² and private health insurance, undergoing laparoscopic RYGB in 2004, was 18.3 (standard error [SE] .36) kg/m² at year 5 and 17.6 (SE .49) kg/m² at year 10.

CONCLUSION

RYGB results in clinically significant and durable weight loss. Attendance at periodic follow-up visits does not appear to be associated with long-term weight loss outcomes. Future work should focus on strategies to remove barriers to post-operative care.

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

BACKGROUND

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

OBJECTIVE

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

SETTING

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

RESULTS

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

CONCLUSION

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

Impact of metabolic surgery on cost and long-term health outcome: a cost-effectiveness approach

BACKGROUND

The increase in obesity has become a major public health concern. Morbid obesity is associated with co-morbidities, reduced quality-of-life, and death. Metabolic surgery (MS) is the most effective treatment for obesity.

OBJECTIVES

The aim of this study was to evaluate the costs and outcomes of MS compared with no surgery in patients with a body mass index ≥30 kg/m².

SETTING

Health care system, Austria METHODS: A total of 177 patients who underwent MS were documented retrospectively, based on the hospital records of 2 specialized centers in Austria, over a 1-year period. At baseline 26.0% of patients exhibited type 2 diabetes (T2D), 52.5% cardiovascular disease (CVD), 23.2% hyperlipidemia, and 23.7% depression. Following the observation period, a Markov chain simulation model was developed to analyze the long-term consequences of T2D, including diabetic complications, CVD, hyperlipidemia, depression, non-alcoholic steatohepatitis (NASH), myocardial infarction, and stroke, over a total of 20 years. Direct medical costs were expressed in 2017 euros from the payer's perspective. Quality-adjusted life years (QALYs), life years (LYs), and costs were discounted.

RESULTS

MS led to costs of €40,427 and 9.58 QALYs (15.58 LYs) per patient over 20 years. No MS was associated with €64,819 and 6.33 QALYs (13.92 LYs). Total cost-savings amounted to €24,392, which offset the cost of the procedure including re-operations. Over 20 years MS saved -6.7 patient-years per patient with T2D, -5.8 patient-years with CVD, -1.5 patient-years with hyperlipidemia, -1.8 patient-years with depression, and -3.8 patient-years with NASH.

CONCLUSION

MS is associated with substantial savings in long-term costs, expected health benefits, and reduced onset of complications. MS significantly increases quality of life.

Roux-en-Y to One Anastomosis Gastric Bypass Conversion: Description of a Novel Technique

Introduction: Roux-en-Y gastric bypass (RYGB) remains among the most widely performed bariatric procedures. A significant decline in its indication has been observed due to weight regain and reappearance of comorbidities. Moreover, the lack of effective therapeutic alternatives after failure justifies why other techniques are more frequently chosen. We present a novel technique to convert a failed RYGB into a one anastomosis gastric bypass (OAGB). Case Presentation: A 43-year-old male patient with a body mass index (BMI) of 47 kg/m2 and several comorbidities was submitted to RYGB. Initially his surgery was successful, but after 7 years he visited the bariatric and metabolic surgery clinic with reappearance of all comorbidities, and the same BMI as before having bariatric surgery. After proper evaluation and preparation, conversion to OAGB was decided. After anatomy identification, the alimentary limb was transected 20 cm distal to the gastrojejunal anastomosis, and a new anastomosis with the common channel (CC) was created, to form a new long afferent biliopancreatic limb and a new short efferent CC. Results: The surgical procedure and postoperative course were uneventful. One year after the procedure the patient's BMI was 36 kg/m2. He has been able to stop all medications and therapies related to previous comorbidities. To date, the patient has good dietary and supplementation adherence resulting in no nutritional deficiencies, or gastrointestinal symptoms. Conclusion: This new surgical technique is safe and feasible. Short-term results have shown reasonable weight loss (WL), and especially remission of comorbidities with an improved quality of life.

The feasibility of modified pancreatogastrostomy in vivo and its effect on intestinal microecology

PURPOSE

To evaluate the feasibility of modified binding pancreatogastrostomy (MBPA) by comparing it with traditional pancreatogastrostomy (TPA) and to determine the surgical effects on the intestinal microecology.

METHODS

The surgical effects on the intestinal microecology of female Bama minipigs (n = 20) were determined by measuring the expressions of the intestinal microbial proteins in the gastric juice, gastric mucosa, and feces before and after MBPA and TPA. We then constructed an integrated interaction network based on the metabolomics and 16S amplicon data, the microbiota, the metabolites, and the associated pathways.

RESULTS

The average time required for anastomosis was significantly lower after MBPA than after TPA, but the breaking force did not significantly differ between them. We identified 25 and 51 differentially expressed metabolites and microbiota, respectively. An interaction network was constructed using 16 metabolites (including pyruvic and lactic acids), 27 microbiota (including Ruminococcaceae_UCG-00) and six pathways (including pyruvate metabolism).

CONCLUSION

Anastomosis might be achieved sooner and with less pancreatic leakage using MBPA compared with TPA. Pancreatogastrostomy inhibits Ruminococcaceae activity, leading to increased expressions of pyruvic and lactic acids in the gut.

Improvement of Lipid Profile after One-Anastomosis Gastric Bypass Compared to Sleeve Gastrectomy

Fewer studies compared the improvement of plasma lipid levels after different types of surgery, in particular compared to one-anastomosis gastric bypass (OAGB). The aim of our study was to investigate how laparoscopic sleeve gastrectomy (LSG) and OAGB impact on weight loss and lipid profile 18 months after surgery, in patients with severe obesity. Forty-six patients treated with OAGB were matched to eighty-eight patients submitted to LSG. Weight loss after OAGB (33.2%) was more evident than after LSG (29.6%) (p = 0.024). The difference in the prevalence of dyslipidemia showed a statistically significant reduction only after OAGB (61% versus 22%, p < 0.001). After adjustment for delta body mass index (BMI), age and sex, we demonstrated a statistically significant decrease of the differences between the changes before and after (delta Δ) the two surgery procedures: Δ total cholesterol values (p < 0.001), Δ low density lipoprotein-cholesterol values (p < 0.001) and Δ triglycerides values (p = 0.007). Patients with severe obesity undergoing to OAGB presented a better improvement of lipid plasma values than LSG patients. The reduction of lipid plasma levels was independent of the significant decrease of BMI after surgery, of age and of sex.

Imaging features in management of laparoscopic mini/one anastomosis gastric bypass post-surgical complications

Obesity is a widespread pathology among the population related to an increase in mortality and morbidity of patients. Bariatric surgery provides several forms of treatment for obese patients. Laparoscopic mini/one anastomosis gastric bypass (MGB/OAGB) is a recent low risk bariatric surgical procedure common in a large number of countries in the treatment of severe obesity. MGB/OAGB, compared to other bariatric surgery techniques, offers the significant technical improvement of requiring only one anastomosis in place of two. In this scenario, diagnostic imaging takes a significant role in the postoperative period, to evaluate the outcomes of surgical treatment and to detect possible complications both in early and late postoperative period. The prevalent radiological procedure to investigate suspicions of clinical post-operative complications is Computed tomography (CT) with oral and intravenous contrast administration. This pictorial essay aims to illustrate and identify normal radiological aspects of MGB/OAGB and post-surgery complication imaging features. We think that this article will serve to familiarize all the specialists with the diagnostic imaging of MGB/OAGB.

•

Laparoscopic mini/one anastomosis gastric bypass (MGB/OAGB) is a recent metabolic/bariatric surgery (MBS) technique that proved safe and valid for patients who were morbidly obese as a malabsorptive or metabolic gastric bypass.

•

Diagnostic imaging takes a significant role in the postoperative period, to detect possible complications both in the early and late postoperative period.

•

Water-soluble contrast upper gastrointestinal (UGI) series represent the first radiological modality in the detection of early postoperative complications.

•

Computed tomography (CT) is a more frequently used imaging technique in the clinical suspicion of possible early and late postoperative complications.

Outcomes of the One Anastomosis Gastric Bypass with Various Biliopancreatic Limb Lengths: a Retrospective Single-Center Cohort Study

Introduction

One anastomosis gastric bypass (OAGB) is an effective and safe treatment for morbidly obese patients. Longer biliopancreatic (BP) limb length is suggested to result in better weight loss outcomes, but to date, no data are available for the OAGB to substantiate this. We hypothesized that applying a longer BP-limb length in the higher BMI classes would result in more weight reduction so that the attained BMI would be comparable to patients with a lower BMI, thereby compensating for differences in baseline BMI.

Method

A retrospective cohort study in patients who underwent a primary OAGB at a teaching hospital in the Netherlands between January 2015 and December 2016. BP-limb length was tailored based on preoperative BMI. Patients were divided into three different groups depending on the length of the BP-limb: 150, 180, and 200 cm. Weight loss outcomes after 1 and 3 years and resolution of comorbidities were compared between these groups.

Results

Of the 632 included patients, a BP-limb length of 150 cm was used in 172 (27.2%), 180 cm in 388 (61.4%), and 200 cm in 72 (11.4%) patients. Despite more BMI loss, %EWL was lower and attained BMI remained higher in the groups with longer BP-limb lengths. After adjustment for the confounder preoperative BMI, longer BP-limb lengths were not associated with higher BMI loss. There was no difference in remission rates of comorbidities.

Conclusion

Attained BMI remained higher in spite of tailoring BP-limb length according to baseline BMI with no differences in remission rates of comorbidities.

Graphical Abstract

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

INTRODUCTION

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

INTRODUCTION

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

Incidence of Dumping Syndrome after Sleeve Gastrectomy, Roux-en-Y Gastric Bypass and One-Anastomosis Gastric Bypass

PURPOSE

Dumping syndrome (DS) is an important but often underreported problem occurring after bariatric surgery. It is believed that gastric bypass procedures like Roux-en-Y Gastric By-pass (RYGB) and One-Anastomosis Gastric Bypass (OAGB) are more likely to cause DS than the pylorus-preserving Sleeve Gastrectomy (SG). The aim of this study was to evaluate the incidence of DS in patients undergoing SG, RYGB and OAGB.

MATERIALS AND METHODS

A retrospective clinical study with 180 patients undergoing SG (n=50), RYGB (n=53) and OAGB (n=77) between 2016-2018 was performed. All clinical and demo-graphic data were assessed. The percentage of excess weight loss (%EWL) was used to evaluate weight reduction. 127/180 (70.6%) patients took part in an additional phone interview. The incidence of DS was evaluated using validated Sigstad Score.

RESULTS

Information about the occurrence of dumping symptoms and patient satisfaction was obtained from 127 patients. Median follow-up was 20.0±11.4 months. Significant differences between the surgical procedures were found for the duration of surgery, complications, weight loss, incidence of DS and satisfaction postoperatively. DS occurred in 15.6% after SG, 56.4% after RYGB and 42.9% after OAGB. A higher weight loss was observed in patients who experienced dumping symptoms.

CONCLUSION

The present results show a clear superiority of SG regarding both perioperative results and incidence of DS compared to RYGB and OAGB and may impact clinicians and patients in their choice of procedure.

Conversion of One-Anastomosis Gastric Bypass (OAGB) to Roux-en-Y Gastric Bypass (RYGB) is Effective in Dealing with Late Complications of OAGB: Experience from a Tertiary Bariatric Center and Literature Review

Purpose

Both primary and revisional bariatric surgery are on the rise due to global obesity pandemic. This study aimed to assess the indications for revision after one-anastomosis gastric bypass (OAGB) and the outcomes after laparoscopic conversion of OAGB to roux-en-y gastric bypass (RYGB).

Materials and Methods

Retrospective review on patients that had undergone conversion of OAGB to RYGB between June 2007-June 2019 in a tertiary bariatric center, followed by literature review.

Results

Out of 386 revisional bariatric surgery, a total of 14 patients underwent laparoscopic conversion of OAGB to RYGB. The mean age was 44.7 with 71% female. The mean pre-revision BMI was 29.2 kg/m². The primary indications for revision were bile reflux (n=7), marginal ulcer (n=3), inadequate weight loss or weight regain (IWL/WR) (n=3) and protein-calorie malnutrition (n=1). Conversion of OAGB to RYGB was completed laparoscopically in all cases. The mean length of stay was 4.1 days. There was no intraoperative or early post-operative complication. The mean total weight loss (rTWL%) after revision at year one, year three and year five post-revision were 11.5%, 18.1% and 29.1%, respectively. All patients achieved resolution of bile reflux and marginal ulcer. There was no mortality in this cohort.

Conclusion

Bile reflux, marginal ulcer, IWL/WR and malnutrition were the main indications for revision after OAGB in this study. In concordance with the available evidence, laparoscopic conversion of OAGB to RYGB was safe and effective in dealing with late complications of OAGB.

Controlling Nutritional Status (CONUT) Score and Micronutrient Deficiency in Bariatric Patients: Midterm Outcomes of Roux-en-Y Gastric Bypass Versus One Anastomosis Gastric Bypass/Mini Gastric Bypass

BACKGROUND

Two of the most common bariatric procedures performed worldwide are Roux-en-Y gastric bypass (RYGB) and one anastomosis gastric bypass (OAGB). Comparative data regarding nutritional status are lacking and no previous study focus on malnutrition according to a validated score.

METHODS

Retrospective data from a single institution were reviewed. Anthropometric variables and nutritional data were assessed. The primary aim was to analyze and compare the nutritional status before and 3 years after RYGB vs OAGB using the controlling nutritional status (CONUT) score. The incidence of micronutrient deficiency and the remission of comorbidities in each group were defined as secondary outcomes.

RESULTS

Fifty-seven patients in each arm were enrolled. A 3-year mild malnutrition (CONUT score 2-3) was found in 38% and 37.05% in the RYGB and OAGB groups, respectively (p > 0.05). In terms of percentage of total weight loss (%TWL) and percentage of adjustable weight loss (%AWL), no differences were found between OAGB and RYGB groups. OAGB and RYGB patients had similar vitamin deficiencies. Anemia, hypoproteinemia, hypoalbuminemia, and hypocalcemia were comparable between groups. At 3-year follow-up, total protein and albumin values were similar between arms while prealbumin deficit was more frequent after OAGB than after RYGB. The rate of type 2 diabetes (87.5% in OAGB and 92% in RYGB), arterial hypertension (51.6% in OAGB and 58.3% in RYGB), and dyslipidemia (69.7% in OAGB and 78.6% in RYGB) remission was not significantly different between the two groups.

CONCLUSIONS

Postoperative CONUT score, micronutrient deficiency, comorbidity remission, and improvement of anthropometric parameters 3 years postoperatively were comparable between RYGB and OAGB groups.

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.

One Anastomosis Gastric Bypass Versus Roux-en-Y Gastric Bypass for Obesity: a Systematic Review and Meta-Analysis of Randomized Clinical Trials

INTRODUCTION

We aim to compare the efficacy and safety outcomes of one anastomosis gastric bypass (OAGB) with Roux-en-Y gastric bypass (RYGB).

METHODS

We searched Ovid Medline, Ovid Embase, and the Cochrane Library from inception to May 14, 2019, without language restrictions, for randomized clinical trials comparing OAGB with RYGB in obesity. Quality of included trials was assessed by Cochrane Collaboration's tool; quality of evidence was evaluated by GRADE approach. The primary outcome was excess body mass index (BMI) loss at 2 years.

RESULTS

We identified 206 reports; after exclusions, three trials with a total of 733 patients were eligible for analysis. Compared with RYGB, OAGB was associated with more excess BMI loss at 2 years (mean difference (MD), 10.22; 95% CI, 3.05 to17.40; I² = 95%; low-quality evidence), with benefit seen in OAGB using non-obese patients (MD, 17.10; 95% CI, 15.76 to18.44; P for interaction = 0.007 ) and no benefit in OAGB using standard length of biliopancreatic limb (MD, 6.49; 95% CI, - 1.09 to 14.08). Moreover, individuals allocated to OAGB compared with RYGB had a higher remission rate of type 2 diabetes(T2D) (risk ratio (RR), 1.13; 95% CI, 1.01 to 1.27; I² = 0%). No statistically significant difference was found between the two surgical groups in adverse events.

CONCLUSION

OAGB is possibly associated with more body weight loss compared with RYGB in patients with obesity, despite the low quality of evidence caused by inconsistent of the effect of biliopancreatic limb length in OAGB group. This benefit appears to be confined to OAGB using the extended length of the biliopancreatic limb but not to OAGB using the standard length of the biliopancreatic limb, compared with RYBG. Additional large clinical studies are needed to assess the impact of limb length in OAGB.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Short-Term Changes on Body Composition and Bone Mass After One-Anastomosis Gastric Bypass: a Prospective Observational Study

PURPOSE

Bariatric surgery generates a large weight loss. It is considered a successful surgery when 50% of the excess weight loss is reached. However, this measure does not include some variables that may have a direct impact on a patient's health, such as fat-free mass (FFM) or bone mass. Therefore, the aim of this study is to evaluate body composition and bone mass in patients undergoing one-anastomosis gastric bypass (OAGB).

METHODS

A prospective observational study was performed in patients undergoing OAGB. Body composition and bone mass were evaluated by bioelectrical impedance analysis at baseline (1 day prior to surgery), at 6 and 12 months after surgery.

RESULTS

A total of 94 patients (67% females and 33% males) were included in the study. The excess BMI loss at 6 and 12 months after surgery was 97.9 ± 20.1% and 110.2 ± 30.5% respectively. The FFM showed a reduction of 6.6 ± 4.8 kg (p < 0.01) 6 months after surgery and of 7.9 ± 4.9 kg (p < 0.01) at 12 months, meaning a decrease of 10.5 ± 7.3% and a 12.9 ± 6.6% respectively. The bone mass decrease was 10.1 ± 6.9% (p < 0.01) and 12.9 ± 6.5% (p < 0.01) at 12 months after OAGB.

CONCLUSIONS

OAGB obtains a relevant weight loss in patients with morbid obesity, mainly, due to fat mass reductions. However, this procedure also provokes FFM and bone mass decreases, especially in females, but not significantly greater than other restrictive or mixed procedures.

Internal Hernia After One Anastomosis Gastric Bypass (OAGB): Lessons Learned from a Retrospective Series of 3368 Consecutive Patients Undergoing OAGB with a Biliopancreatic Limb of 150 cm

Background

Internal hernia (IH) represents a relatively common and well-known complication after Roux-en-Y gastric bypass. IH after one anastomosis gastric bypass (OAGB) is less frequent and rarely reported in the literature. This study presents a series of IH after OAGB observed in a high-volume bariatric center.

Methods

Data of patients who underwent OAGB with an afferent limb of 150 cm between May 2010 and September 2019 were prospectively collected and retrospectively analyzed. Data of patients undergoing surgery for IH during follow-up were collected and analyzed.

Results

Ninety-six patients out of 3368 with a history of OAGB had intestinal incarceration in the Petersen’s orifice (2.8%). Specificity and sensitivity of computed tomography scans in the diagnosis of IH were 59% and 76%, respectively. The mean timeframe between OAGB and surgery for IH was 21.9±18.3 months. Mean body mass index at the time of IH surgery was 24.7 ± 3.6. Surgery was completed laparoscopically in 96.8% of cases. Nine patients (9.3%) had signs of bowel hypovascularization. In all patients, the herniated bowel was repositioned, and the Petersen’s orifice was closed, without the need for bowel resection. Mean hospital stay was 1.9 ± 4.8 days. The postoperative morbidity rate was 8.3%. Long-term IH relapse was observed in 14 patients; signs of bowel hypovascularization due to incarceration in a small orifice was observed in eight of these patients (57%).

Conclusions

Incidence of IH after OAGB is 2.8%. IH is associated with a low rate of bowel ischemia and the need for intestinal resection.

Characterization of one anastomosis gastric bypass and impact of biliary and common limbs on bile acid and postprandial glucose metabolism in a minipig model

The alimentary limb has been proposed to be a key driver of the weight-loss-independent metabolic improvements that occur upon bariatric surgery. However, the one anastomosis gastric bypass (OAGB) procedure, consisting of one long biliary limb and a short common limb, induces similar beneficial metabolic effects compared to Roux-en-Y Gastric Bypass (RYGB) in humans, despite the lack of an alimentary limb. The aim of this study was to assess the role of the length of biliary and common limbs in the weight loss and metabolic effects that occur upon OAGB. OAGB and sham surgery, with or without modifications of the length of either the biliary limb or the common limb, were performed in Gottingen minipigs. Weight loss, metabolic changes, and the effects on plasma and intestinal bile acids (BAs) were assessed 15 days after surgery. OAGB significantly decreased body weight, improved glucose homeostasis, increased postprandial GLP-1 and fasting plasma BAs, and qualitatively changed the intestinal BA species composition. Resection of the biliary limb prevented the body weight loss effects of OAGB and attenuated the postprandial GLP-1 increase. Improvements in glucose homeostasis along with changes in plasma and intestinal BAs occurred after OAGB regardless of the biliary limb length. Resection of only the common limb reproduced the glucose homeostasis effects and the changes in intestinal BAs. Our results suggest that the changes in glucose metabolism and BAs after OAGB are mainly mediated by the length of the common limb, whereas the length of the biliary limb contributes to body weight loss.NEW & NOTEWORTHY Common limb mediates postprandial glucose metabolism change after gastric bypass whereas biliary limb contributes to weight loss.

Sleeve Gastrectomy Failure-Revision to Laparoscopic One-Anastomosis Gastric Bypass or Roux-n-Y Gastric Bypass: a Multicenter Study

INTRODUCTION

Laparoscopic sleeve gastrectomy (LSG) is the most popular bariatric procedure performed worldwide. However, many patients undergo secondary surgery due to either weight-related and complication-related reasons or both. Conversional options vary with one-anastomosis gastric bypass (OAGB) and Roux-n-Y gastric bypass (RYGB) being the most common. The aim of the study was to assess the safety and efficacy of converting failed LSG to either OAGB or RYGB, and compare weight-related results and post-conversion complications.

METHODS

Retrospective review of hospital records of patients who underwent conversion from LSG to either RYGB or OAGB due to insufficient weight loss or weight regain in 7 bariatric centers between 2013 and 2019. Data retrieved included demographics, anthropometrics, comorbidities, indication for conversion, conversion type, complications, and weight loss.

RESULTS

During the study period, 396 patients were included in the study. Eighty-four (21%) patients were lost to follow-up. RYGB and OAGB were performed in 119 and 144 patients, respectively. Mean age and body mass index (BMI) at revision were 44.2 years (range 19-72) and 40.6 ± 5.9 kg/m² (range 35-71), respectively. Of these, 191 (73%) were female. Percent total body weight loss (%TWL) was 16% ± 1% for the RYGB group vs. 23% ± 12% for the OAGB group (p = 0.0007) at a median follow-up of 29 months (range 7-78 months) following conversion. Gastroesophageal reflux disease (GERD) was significantly higher 1 year following conversion to OAGB vs. RYGB occurring in 25 (17.4%) and 9 (7.6%) patients, respectively (p = 0.018).

CONCLUSIONS

Conversion of LSG to OAGB, compared to RYGB, results in increased weight loss but a higher rate of GERD and potential nutritional deficiencies.

Bridged one-anastomosis gastric bypass: technique and preliminary results

PURPOSE

One-anastomosis gastric bypass (OAGB) is an established bariatric procedure performed worldwide. We developed a modification of OAGB leaving a bridge at the cranial 2 cm of the fundus as a gastro-gastric fistula to allow for endoscopic access to the bypassed stomach. We present the preliminary results of 44 patients who underwent this technique in our hospital.

METHODS

We analyzed, retrospectively, data collected prospectively on 44 patients who underwent our bridged one-anastomosis gastric bypass (BOAGB) procedure between September, 2018 and November, 2020.

RESULTS

The mean age of the patients was 45.2 ± 9.3 years (range 20-66 years). The mean preoperative body mass index (BMI), weight, and HbA1c values were 41.5 ± 6.4 kg/m² (range 35-59), 116 ± 22.7 kg, and 8.2 ± 2.1%, respectively. After a median follow-up period of 18 months (11-26 months), the mean postoperative BMI was 28.4 ± 3.2 kg/m² (range 21-38), the mean total weight loss was 35.8 ± 13.5 kg (range 20-80 kg), and the mean percentage of excess weight loss (%EWL) and the percentage of total weight loss (%TWL) were 79.8 ± 16.1% (range 47-109) and 30.6 ± 6.9% (range 19-48), respectively. The mean postoperative HbA1c level was 6.3 ± 0.9%. There were two early complications (stenosis and bleeding) and one late complication (marginal ulcer).

CONCLUSION

Patients who underwent BOAGB lost weight similarly to those who underwent OABG as reported in the literature, without an apparent increase in complications related to the technique. Randomized studies with longer term follow-up are needed.

Conversion of laparoscopic sleeve gastrectomy after weight loss failure into laparoscopic one anastomosis gastric bypass: short-term safety and efficacy and effect of indications on outcome

BACKGROUND

Revisional surgery after failed laparoscopic sleeve gastrectomy (LSG) is growing and laparoscopic one anastomosis gastric bypass (LOAGB) has been proposed as a revisional procedure due to its combined restrictive and malabsorptive effects. The aim is to study short-term complications and weight loss (WL) results of the revisional LOAGB after LSG for the two-weight loss failure (WLF) types [insufficient weight loss (IWL) and weight regain (WR)] and to assess the possible effects of these two types of failure and gastric tube anatomy on the final outcome.

METHODS

The data of 28 patients who completed 1-year follow-up for their revisional LOAGB after their failed LSG were assessed and statistically correlated to leakage and one year WL results.

RESULTS

Operative time was 96 ± 17.4 min. Leakage occurred in 2 patients (7.1%); the small number of leak patients does not allow statistical analysis for leakage. Percentage of excess weight loss (%EWL) at one year was 79.0 ± 14.4%; percentage of total weight loss (%TWL) was 31.7 ± 6.4%. %EWL was 84.2 ± 13.1 with IWL and 73.0 ± 13.9 with WR (P = 0.036). %TWL was 35.0 ± 5.2 with IWL and 27.8 ± 5.5 with WR (P = 0.001). %TWL at persistent fundus, diffusely dilated, and nondilated stomach were 38.98 ± 4.57, 31.3 ± 5.33, and 28.54 ± 5.91, respectively (P = 0.006).

CONCLUSION

LOAGB is a highly effective and safe procedure as a revision after LSG with WLF. Patients with IWL and patients with persistent fundus lost more weight than those with WR and those with diffuse stomach dilation or nondilation, respectively.

Type 2 diabetes mellitus status in obese patients following sleeve gastrectomy or one anastomosis gastric bypass

This study aims to compare sleeve gastrectomy (SG) and one anastomosis gastric bypass (OAGB) in terms of remission of type 2 diabetes mellitus (T2DM) in obese patients. All T2DM patients were followed-up for at least 36 months. The primary outcome was remission of T2DM. Secondary endpoints included weight reduction and the procedure’s impact on quality of life. In total, 53/1177 morbidly obese patients who underwent SG (Group A, n = 28) or OAGB (Group B, n = 25) had T2DM. Preoperatively, the mean Body Mass Index (BMI) values were 52.2 ± 8.5 kg/m² and 52.9 ± 10.9 kg/m² for Group A and Group B, respectively. Six patients in Group A were insulin dependent, while 8 were insulin dependent in Group B. After 36 months, diabetes remission was achieved by only 10 patients (35.7%) in Group A. However, in Group B, 22 patients (88%) remained off antidiabetic agents (p < 0.0001), with ΔHbA1c (%) reaching 1.4 ± 1.5% in Group A and 2.7 ± 2.1% in Group B (p = 0.02). Excess weight loss% (%EWL) was again significantly different between the two groups (MA = 79.8 ± 14.5%, MB = 93.3 ± 16.0%, p = 0.003). OAGB is more effective in improving glycaemic control and %EWL, with almost immediate resolution of diabetes, as well as long-term weight loss.