MGB-OAGB: Effect of Biliopancreatic Limb Length on Nutritional Deficiency, Weight Loss, and Comorbidity Resolution

Metabolic outcomes in obese mice undergoing one-anastomosis gastric bypass (OAGB) with a long or a short biliopancreatic limb

One-anastomosis gastric bypass (OAGB) has gained importance as a simple, safe, and effective operation to treat morbid obesity. We previously found that Roux-en-Y gastric bypass surgery with a long compared with a short biliopancreatic limb (BPL) leads to improved weight loss and glucose tolerance in obese mice. However, it is not known whether a long BPL in OAGB surgery also results in beneficial metabolic outcomes. Five-week-old male C57BL/6J mice fed a high-fat diet (HFD) for 8 weeks underwent OAGB surgery with defined BPL lengths (5.5 cm distally of the duodenojejunal junction for short and 9.5 cm for long BPL), or sham surgery combined with caloric restriction. Weight loss, glucose tolerance, obesity-related comorbidities, endocrine effects, gut microbiota, and bile acids were assessed. Total weight loss was independent of the length of the BPL after OAGB surgery. However, a long BPL was associated with lower glucose-stimulated insulin on day 14, and an improved glucose tolerance on day 35 after surgery. Moreover, a long BPL resulted in reduced total cholesterol, while there were no differences in the resolution of metabolic dysfunction-associated steatotic liver disease (MASLD) and adipose tissue inflammation. Tendencies of an attenuated hypothalamic-pituitary-adrenal (HPA) axis and aldosterone were present in the long BPL group. With both the short and long BPL, we found an increase in primary conjugated bile acids (pronounced in long BPL) along with a loss in bacterial Desulfovibrionaceae and Erysipelotrichaceae and simultaneous increase in Akkermansiaceae, Sutterellaceae, and Enterobacteriaceae. In summary, OAGB surgery with a long compared with a short BPL led to similar weight loss, but improved glucose metabolism, lipid, and endocrine outcomes in obese mice, potentially mediated through changes in gut microbiota and related bile acids. Tailoring the BPL length in humans might help to optimize metabolic outcomes after bariatric surgery.NEW & NOTEWORTHY Weight loss following OAGB surgery in obese mice was not influenced by BPL length, but a longer BPL was associated with improved metabolic outcomes, including glucose and lipid homeostasis. These changes could be mediated by bile acids upon altered gut microbiota. Further validation of these findings is required through a randomized human study.

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.

Measuring Small Bowel Length in Bariatric Surgery: An Ex Vivo Laparoscopic Training Experiment

INTRODUCTION

Determining limb length in gastric bypass procedures is a crucial step to ensure significant weight loss without risking malnutrition. This study investigated the effect of ex vivo training on the skills needed to determine limb lengths.

MATERIALS AND METHODS

This was a single-center ex vivo training experiment in a teaching hospital in the Netherlands. We designed a training exercise with marked ropes in a laparoscopic trainer box. All ten surgical residents participated and practiced the skill of estimating limb length. Before and after the two-week period their results on a 150-centimeter limb length task were evaluated.

RESULTS

Before training, 10 surgical residents estimated 150 centimeters of small bowel with an absolute deviation of 21% [range 9-30]. After the training experiment, the residents measured with 8% [2-20] deviation (P = .17). The 8 residents who trained sufficiently improved statistically significantly to an absolute deviation of 5% [2-17] (P = .012). Over 70% of the participants felt their skills had improved.

CONCLUSIONS

With sufficient training, surgical residents' skills in measuring small bowel length improved when tested in an ex vivo model. Residents became more confident in their laparoscopic measurement skills. This ex vivo training model is a alternative and addition to on-site training.

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

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

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

Medtronic.

Revisional One-Step Bariatric Surgical Techniques After Unsuccessful Laparoscopic Gastric Band: A Retrospective Cohort Study with 2-Year Follow-up

BACKGROUND

Laparoscopic adjustable gastric banding (LAGB) has high reported rates of revision due to poor weight loss (WL) and high complication rates. Yet, there is yet to be a consensus on the best revisional procedure after unsuccessful LAGB, and studies comparing different revisional procedures after LAGB are still needed.

METHODS

This was a retrospective cohort study that compared the outcomes of one-step revisional Roux-en-Y gastric bypass (rRYGB), one-anastomosis gastric bypass (rOAGB), or laparoscopic sleeve gastrectomy (rLSG) after LAGB. WL, complications, resolution of associated medical conditions, and food tolerance were assessed with a post hoc pairwise comparison one-way analysis of variance (ANOVA) throughout a 2-year follow-up.

RESULTS

The final analysis included 102 (rRYGB), 80 (rOAGB), and 70 (rLSG) patients. After 2 years, an equal percentage of excess weight loss was observed in rOAGB and rRYGB (both >90%; p=0.998), significantly higher than that in rLSG (83.6%; p<0.001). In our study, no leaks were observed. rRYGB had higher complication rates according to the Clavien-Dindo classification (10.8% vs. 3.75% and 5.7% in rOAGB and rLSG, respectively, p=0.754), and re-operations were not statistically significant. Food tolerance was comparable between rOAGB and rRYGB (p = 0.987), and both had significantly better food tolerance than rLSG (p<0.001). The study cohorts had comparable resolution rates for associated medical problems (p>0.60).

CONCLUSION

rOAGB and rRYGB had better outcomes after LAGB than rLSG regarding WL, feasibility, food tolerance, and safety. rOAGB had significantly higher rates of nutritional deficiencies.

One Anastomosis Gastric Bypass vs. Sleeve Gastrectomy in the Remission of Type 2 Diabetes Mellitus: A Retrospective Analysis on 3 Years of Follow-Up

Background. Obesity is a prevalent condition associated with various comorbidities, impacting mortality, fertility, and quality of life. Its relationship with type 2 diabetes mellitus (DMII) is well established, with nearly 44% prevalence. Bariatric surgery has proven crucial for treating both obesity and DMII. The comparison between surgical techniques, such as sleeve gastrectomy (SG) and one anastomosis gastric bypass (OAGB), remains controversial in terms of glycemic control efficacy. This retrospective study aimed to assess DMII remission efficacy between SG and OAGB after 36 months. Methods. From January 2016 to September 2020, 201 patients who underwent SG and OAGB for morbid obesity associated with DMII were accurately followed-up with for 36 months, focusing on %HbA1c, DMII remission, anthropometric results, and nutrient deficiency. Results. Although DMII remission did not exhibit statistical significance between the groups (82% vs. 93%, SG vs. OAGB, p = 0.051), OAGB demonstrated a more robust association with glycemic control (Odds Ratio 0.51) throughout the entire follow-up and yielded superior anthropometric outcomes. Notably, nutrient deficiencies, excluding cholecalciferol, iron, and riboflavin, did not show significant intergroup differences. Conclusions. This study contributes valuable insights into the extended-term efficacy of SG and OAGB in DMII remission. The nuanced findings underscore the multifaceted nature of metabolic outcomes, suggesting that factors beyond weight loss influence diabetes resolution. Larger comparative studies are warranted to comprehensively address this issue.

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Change in Mineral Status After Bariatric Surgery: a Meta-analysis

BACKGROUND

The risk of protein and vitamin deficiencies after bariatric surgery has been well studied, but the change in mineral status has not gotten enough attention. This study aimed to perform a meta-analysis regarding the change in mineral levels after bariatric surgery and the prevalence of postoperative mineral deficiency, with subgroup analyses of different surgical procedures, study regions, and follow-up time.

METHODS

CENTRAL, PubMed, and EMBASE were searched for related articles. Meta-analysis, subgroup analysis, and sensitivity analysis were performed if necessary.

RESULTS

A total of 107 articles with 47,432 patients were included. The most severe mineral deficiency after bariatric surgery was iron (20.1%), followed by zinc (18.3%), copper (14.4%), chlorine (12.2%), phosphorus (7.5%), and calcium (7.4%). Serum concentrations of potassium, sodium, selenium, manganese, and molybdenum showed no significant change before and after surgery. Subgroup analyses revealed that SG had fewer deficiencies in serum iron, calcium, zinc, magnesium, phosphorus, copper, and selenium than RYGB. OAGB showed a higher incidence of serum iron and zinc deficiencies than RYGB. Studies conducted in different regions also found various mineral statuses after surgery. Studies with follow-up ≥ 5 years had a lower prevalence of zinc, copper, and selenium deficiencies than follow-up < 5 years.

CONCLUSION

A high deficiency rate of serum iron, zinc, copper, chlorine, phosphorus, and calcium was seen after bariatric surgery. The difference in surgical procedures, study regions, and follow-up time may affect postoperative mineral status; more targeted mineral supplement programs are needed considering these influencing factors.

Malnutrition Following One-Anastomosis Gastric Bypass: a Systematic Review

Severe malnutrition following one-anastomosis gastric bypass (OAGB) remains a concern. Fifty studies involving 49,991 patients were included in this review. In-hospital treatment for severe malnutrition was needed for 0.9% (n = 446) of patients. Biliopancreatic limb (BPL) length was 150 cm in five (1.1%) patients, > 150 cm in 151 (33.9%), and not reported in 290 (65%) patients. OAGB was revised to normal anatomy in 126 (28.2%), sleeve gastrectomy in 46 (10.3%), Roux-en-Y gastric bypass in 41 (9.2%), and shortening of BPL length in 17 (3.8%) patients. One hundred fifty-one (33.8%) patients responded to treatment; ten (2.2%) did not respond and was not reported in 285 (63.9%) patients. Eight (0.02%) deaths were reported. Standardisation of the OAGB technique along with robust prospective data collection is required to understand this serious problem.

Roux-en-Y versus one-anastomosis gastric bypass (RYSA study): weight loss, metabolic improvements, and nutrition at 1 year after surgery, a multicenter randomized controlled trial

OBJECTIVE

Although it has been suggested that one-anastomosis gastric bypass (OAGB) is metabolically superior to the "gold standard," i.e., Roux-en-Y gastric bypass (RYGB), there is little robust evidence to prove it. Because this result may arise from the typically longer length of bypassed intestine in OAGB, here, the authors standardized the bypass length in RYGB and OAGB and compared weight loss and metabolic outcomes in a randomized controlled trial.

METHODS

The authors randomized 121 bariatric patients to RYGB (n = 61) or OAGB (n = 60) in two Finnish University Hospitals and measured weight; body composition; metabolic features (insulin sensitivity, lipids, inflammation, nutrition); and comorbidities before and 6 and 12 months after the operation.

RESULTS

Total weight loss was similar in RYGB and OAGB at 6 months (mean: 21.2% [95% CI: 19.4-23.0] vs. 22.8% [95% CI: 21.5-24.1], p = 0.136) and 12 months (25.4% [95% CI: 23.4-27.5] vs. 26.1% [95% CI: 24.2-28.9], p = 0.635). Insulin sensitivity, lipids, and inflammation improved similarly between the groups (p > 0.05). Remission of type 2 diabetes and hypercholesterolemia was marked and similar (p > 0.05) but the use of antihypertensive medications was lower (p = 0.037) and hypertension tended to improve more (p = 0.053) with RYGB versus OAGB at 12 months. Higher rates of vitamin D-25 deficiency (p < 0.05) and lower D-25 levels were observed with OAGB versus RYGB throughout the follow-up (p < 0.001). No differences in adverse effects were observed.

CONCLUSIONS

RYGB and OAGB were comparable in weight loss, metabolic improvement, remission of diabetes and hypercholesterolemia, and nutrition at 1-year follow-up. Vitamin D-25 deficiency was more prevalent with OAGB, whereas reduction in antihypertensive medications and hypertension was greater with RYGB. There is no need to change the current practices of RYGB in favor of OAGB.

New Mouse Models of Roux-en Y Gastric Bypass and One Anastomosis Gastric Bypass for Type 2 Diabetes

BACKGROUND

Current bariatric surgery models primarily utilize mice with obesity, overlooking those with type 2 diabetes (T2DM). These models have limitations in replicating clinical procedures accurately and achieving broad applicability. This study aimed to develop novel mouse models of Roux-en-Y gastric bypass (RYGB) and one anastomosis gastric bypass (OAGB) surgeries specifically designed for T2DM research, utilizing simplified surgical techniques closely resembling clinical procedures.

METHODS

Eight-week-old C57/Bl6 mice, except for the Blank-Control group, were induced with T2DM by combining a high-fat diet and streptozotocin injection. RYGB involved creating a 10% gastric pouch, a 4-cm biliopancreatic limb (BL), and a 4-cm Roux limb (RL). Similarly, OAGB maintained a 10% gastric pouch and a 4-cm BL. To assess the efficacy of these models, we measured the body weight and fasting blood glucose (FBG) and conducted intraperitoneal glucose tolerance test (IPGTT), insulin tolerance test (ITT), and liver B-ultrasound, as well as a histopathological analysis of multiple organs 12 weeks post-operation.

RESULTS

The survival rates in the Blank-Control, T2DM-Sham, T2DM-RYGB, and T2DM-OAGB groups were 100% (6/6), 100% (6/6), 85.7% (6/7), and 100% (6/6), respectively. Both RYGB and OAGB surgeries similarly led to sustained weight loss, reduced the FBG levels, improved the IPGTT and ITT results, and alleviated the histopathological manifestations in multiple organs.

CONCLUSION

The innovative mouse models of RYGB and OAGB surgeries effectively improve T2DM. Both surgeries demonstrate comparable efficacy in ameliorating T2DM, even when utilizing a gastric pouch of the same size and the same length of BL in OAGB.

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

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

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.

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.

Revisional Roux-en-Y Gastric Bypass Versus Revisional One-Anastomosis Gastric Bypass After Failed Sleeve Gastrectomy: a Randomized Controlled Trial

Background

High rates of revision surgery have been reported for laparoscopic sleeve gastrectomy (LSG), with weight regain (WR) as the most frequently reported cause. Roux-en-Y gastric bypass (RYGB) is the most commonly performed revision procedure, whereas one-anastomosis gastric bypass (OAGB) is a less popular approach.

Methods

A single-blinded randomized controlled trial was conducted. One hundred seventy-six patients were enrolled and randomized. After loss to follow-up, 80 patients for RYGB and 80 patients for OAGB were analyzed, with a 2-year follow-up. Patients with grade B or higher gastroesophageal reflux disease (GERD) were excluded. Early and late postoperative complications were recorded. Body mass index (BMI), percentage of excess BMI loss (%EBMIL), nutritional laboratory test results, and the resolution of associated medical problems were assessed after revision surgery.

Results

After 2 years, both groups achieved significantly lower BMI than their post-LSG nadir BMI (p < 0.001). The %EBMIL changes showed significantly faster weight loss in the OAGB group than in the RYGB at the 6-month follow-up (mean difference: 8.5%, 95% confidence interval [CI]: 0.2 to 16.9%). However, at 1-year and 2-year follow-ups, the differences were statistically insignificant (p > 0.05). Early and late complications were similar between two groups. Both groups showed improvement or resolution of associated medical problems, with no statistically significant differences after 2 years (p = 1.00).

Conclusion

Both revisional RYGB and OAGB have comparable significant weight loss effects when performed for WR after LSG. After a 2-year follow-up, both procedures were safe, with no significant differences in the occurrence of complications and nutritional deficits.

Graphical abstract

Shortening the Biliopancreatic Limb Length of One Anastomosis Gastric Bypass Maintains Glucose Homeostasis Improvement with Limited Weight Loss

One anastomosis gastric bypass (OAGB) is associated with similar metabolic improvements and weight loss as Roux-en-Y gastric bypass (RYGB). However, this bariatric procedure is still controversial as it is suspected to result in undernutrition. Reducing the size of the biliopancreatic limb of OAGB could be essential to maintain positive outcomes while preventing side effects. The objective of this study was to compare and contrast outcomes of OAGB with two different biliopancreatic limb lengths to RYGB and Sham surgery in obese and non-obese rats. Lean and diet-induced obese Wistar rats were operated on RYGB, OAGB with a short (15 cm OAGB-15) or a long (35 cm OAGB-35) biliopancreatic limb or Sham surgery. Body weight and food intake were monitored over 30 weeks, and rats underwent oral glucose and insulin tolerance tests with a pancreatic and gut hormone secretion assay. Macronutrient absorption was determined by fecal analyses. Statistical analyses used non-parametric one-way or two-way ANOVA tests. Compared to Sham rats, RYGB, OAGB-15 and OAGB-35 rats displayed a significant reduced weight. Weight loss was greater after OAGB-35 than after OAGB-15 or Sham surgery because of transient malabsorption. All OAGB- and RYGB-operated rats displayed an improved pancreatic and gut hormone secretion in response to a meal compared to Sham rats, these effects were independent of limb length, rat weight, and maintained overtime. In conclusion, glucose homeostasis was similarly improved in obese and non-obese OAGB-15 and OAGB-35 rats suggesting that shortening the biliopancreatic limb can improve the metabolic parameters without a major influence on weight.

150-cm Versus 200-cm Biliopancreatic Limb One-Anastomosis Gastric Bypass: Propensity Score-Matched Analysis

BACKGROUND

It has been suggested that shortening the length of the biliopancreatic limb (BPL) to 150 cm in one anastomosis gastric bypass (OAGB) would reduce nutritional complication rates without impairing weight loss outcomes. The aim of this study is to compare patients who underwent OAGB with a 200-cm BPL (OAGB-200) to patients with OAGB with a 150-cm BPL (OAGB-150) in terms of weight loss and late morbidity.

METHODS

This is a monocentric retrospective matched cohort study including patients with a body mass index between 35 and 50 kg/m² who underwent an OAGB-150 or an OAGB-200. Patients were matched 1:1 based on age, sex, and body mass index, prior to bariatric surgery.

RESULTS

In total, 784 patients who underwent OAGB were included (OAGB-150 n = 392 and OAGB-200 (n = 392). There was no significant difference in terms of early morbidity. Regarding late morbidity in patients with an OAGB-150, significantly lower rates for marginal ulcer (OR = 0.4, CI 95% [0.2; 0.8], p = 0.006), incisional hernia (OR = 0.5, CI 95% [0.3; 1], p = 0.041), and bowel obstruction (OR = 0.3, CI 95% [0.1; 0.9], p = 0.039) were reported. Likewise, regarding late nutritional deficiencies, post-OAGB-150, a significantly lower number of patients with hypoalbuminemia (OR = 0.3, CI 95% [0.2; 0.7], p = 0.006), low vitamin B9 (OR = 0.5, CI 95% [0.2; 1], p = 0.044), and low ferritin (OR = 0.5, CI 95% [0.3; 0.8], p = 0.005) were observed. There was no significant difference in the percentage of excess BMI loss at 1, 2, 3, 4, and 5 years.

CONCLUSION

Compared to OAGB-200 in patients with BMI ≤ 50 kg/m², OAGB-150 results in fewer nutritional deficiency rates long term, without impairing weight loss.

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.

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.

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.

Comparative risk of anemia and related micronutrient deficiencies after Roux-en-Y gastric bypass and sleeve gastrectomy in patients with obesity: An updated meta-analysis of randomized controlled trials

Although Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are the most prevalent bariatric surgical procedures, high-level evidence is scarce regarding the assessment of postoperative nutritional risk in RYGB versus SG. Therefore, we performed a systematic review and meta-analysis to compare the risk of anemia and related micronutrient deficiencies after RYGB and SG. We analyzed 10 randomized controlled trials that compared RYGB and SG with reported incidence of postoperative anemia and/or anemia-related micronutrient deficiencies (iron, vitamin B₁₂ , or folate). There were no significant differences in the risk of postoperative anemia (moderate level of evidence), iron deficiency (high level of evidence), or folate deficiency (moderate level of evidence). Patients undergoing RYGB had a higher risk of postoperative vitamin B₁₂ deficiency than those undergoing SG (relative risk, 1.86; 95% confidence interval, 1.15-3.02; p = 0.012; high level of evidence). Our findings imply that patients undergoing RYGB require more stringent vitamin B₁₂ supplementation and surveillance than those undergoing SG. Additionally, our results may aid patients with high concern for anemia and related micronutrient deficiencies in making informed decisions regarding surgical methods based on nutritional risk.

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.

Laparoscopic Small Bowel Length Measurement in Bariatric Surgery Using a Hand-Over-Hand Technique with Marked Graspers: an Ex Vivo Experiment

Introduction

Tailoring limb length in bariatric surgery is a subject of many studies. To acquire the optimal limb length, accurate measurement of the small bowel length is essential.

Objective

To assess the intra- and inter-individual variability of laparoscopic bowel length measurement using a hand-over-hand technique with marked graspers.

Method

Four bariatric surgeons and four surgical residents performed measurements on cadaver porcine intestine in a laparoscopic box using marked graspers. Each participant performed 10 times a measurement of three different lengths: 150, 180, and 210 cm. Acceptable percentage deviation from the goal lengths was defined as less than 10%, while unacceptable deviations were defined as more than 15%.

Results

The bariatric surgeons measured the 150-, 180-, and 210-cm tasks with 4% (CI 0.4, 9), − 6% (CI − 11, − 0.8), and 1% (CI − 4, 6) deviation, respectively. In total, the bariatric surgeons estimated 58 out of 119 times (49%) between the margins of 10% deviation and 36 times (30%) outside the 15% margin. Considerable inter-individual differences were found between the surgeons. The surgical residents underestimated the tasks with 12% (CI − 18, − 6), 16% (CI − 19, − 13), and 18% (CI − 22, − 13), respectively.

Conclusion

Bariatric surgeons estimated bowel length with on average less than 10% deviation. However, this still resulted in 30% of the measurements with more than 15% deviation. There were considerable inter-individual differences between the surgeons and residents structurally underestimated the bowel length. Ascertainment of measurement accuracy and adequate training is essential for bariatric procedures in which limb length is of importance.

Graphical abstract

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.

The first survey addressing patients with BMI over 50: a survey of 789 bariatric surgeons

Background

Bariatric surgery in patients with BMI over 50 kg/m² is a challenging task. The aim of this study was to address main issues regarding perioperative management of these patients by using a worldwide survey.

Methods

An online 48-item questionnaire-based survey on perioperative management of patients with a BMI superior to 50 kg/m² was ideated by 15 bariatric surgeons from 9 different countries. The questionnaire was emailed to all members of the International Federation of Surgery for Obesity (IFSO). Responses were collected and analyzed by the authors.

Results

789 bariatric surgeons from 73 countries participated in the survey. Most surgeons (89.9%) believed that metabolic/bariatric surgery (MBS) on patients with BMI over 50 kg/m² should only be performed by expert bariatric surgeons. Half of the participants (55.3%) believed that weight loss must be encouraged before surgery and 42.6% of surgeons recommended an excess weight loss of at least 10%. However, only 3.6% of surgeons recommended the insertion of an Intragastric Balloon as bridge therapy before surgery. Sleeve Gastrectomy (SG) was considered the best choice for patients younger than 18 or older than 65 years old. SG and One Anastomosis Gastric Bypass were the most common procedures for individuals between 18 and 65 years. Half of the surgeons believed that a 2-stage approach should be offered to patients with BMI > 50 kg/m², with SG being the first step. Postoperative thromboprophylaxis was recommended for 2 and 4 weeks by 37.8% and 37.7% of participants, respectively.

Conclusion

This survey demonstrated worldwide variations in bariatric surgery practice regarding patients with a BMI superior to 50 kg/m². Careful analysis of these results is useful for identifying several areas for future research and consensus building.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08979-w.

One-Anastomosis Gastric Bypass Revision for Gastroesophageal Reflux Disease: Long Versus Short Biliopancreatic Limb Roux-en-Y Gastric Bypass

PURPOSE

One-anastomosis gastric bypass (OAGB) may be associated with refractory gastroesophageal reflux disease (GERD). The nature of this GERD remains unclear. This complication can be treated either with an additional enteroenterostomy without shortening of gastric pouch (long biliopancreatic limb Roux-en-Y gastric bypass (L-BPL-RYGB)) or revision to conventional short biliopancreatic limb Roux-en-Y gastric bypass (S-BPL-RYGB). The objective of this study is to compare the aforementioned procedures in terms of efficacy on GERD symptoms.

MATERIALS AND METHODS

Retrospective analysis between October 2012 and June 2020.

RESULTS

Fifty-two patients underwent OAGB revision to S-BPL-RYGB (n = 21) or L-BPL-RYGB (n = 31) secondary to GERD. Investigation with pH impedance prior to revision was performed in 15 patients showing biliary reflux (BR) in 7 (46.6%), acid reflux (AR) in 6 (40%), and no confirmation in 2. Patients with AR had a revision to S-BPL-RYGB, whereas patients with BR underwent L-BPL-RYGB. Among the patients without pH metry results (n = 37), S-BPL-RYGB was performed for associated disabling digestive disorders or nutritional deficiencies. GERD was treated in 68% of patients with L-BPL-RYGB versus 95% of patients after S-BPL-RYGB. Patients, whose decision for revisional procedure was based on the results of pH impedance testing, did not reveal refractory GERD.

CONCLUSION

L-BPL-RYGB seems appropriate in patients with BR, whereas conversion to S-BPL-RYGB should be preferred if AR is present.

One Anastomosis Gastric Bypass Versus Long Biliopancreatic Limb Roux-en-Y Gastric Bypass

Background

Roux-en-Y gastric bypass (RYGB) is one of the most effective bariatric procedures. The study aimed to explore the value of lengthening the biliopancreatic limb (BPL) in RYGB compared to the outcome of one-anastomosis gastric bypass (OAGB).

Methods

This prospective study included morbidly obese patients divided into two groups. The RYGB group (n = 36) was subjected to long biliary limb Roux-en-Y gastric bypass (LPRYGB), and the OAGB Group (n = 36) had one anastomosis gastric bypass. During follow-up, weight, BMI, percentage of excess body weight loss (%EBWL), resolution of obesity-related comorbidities, and quality of life (QoL) were evaluated.

Results

There was no significant difference in weight and BMI after 3 and 6 months. At 12-month follow-up, weight loss was significantly higher in the OAGB group. After 12 months, the two groups showed significant improvement of comorbid conditions without significant difference between the two groups. The Qol was significantly higher in the LPRYGB group 3, 6, and 12 months after surgery compared to the OAGB group.

Conclusions

Extending the BPL length in RYGB to 150 cm is as effective as OAGB in remission of comorbidities, including diabetes. It was also equally effective in weight reduction in the short term. OAGB was more efficient in weight reduction and a significantly faster operation. LPRYGB showed a better QoL of life 1 year after surgery.

Graphical abstract

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

PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Bariatric surgery and the liver-Mechanisms, benefits, and risks

The prevalence of obesity and metabolic diseases such as type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) has risen dramatically over the past decades. At present, bariatric surgery is the most effective treatment for this global health problem, through effects on food intake, gut hormone secretion, metabolic signaling pathways, and adipose tissue dysfunction. The liver occupies a central role in carbohydrate, protein, and lipid metabolism. Notably, a reduction in hepatic fat content and an improvement in hepatic insulin resistance are among the earliest beneficial effects of bariatric surgery, which has therefore emerged as an attractive treatment option for NAFLD. However, as the scope and popularity of weight loss surgery have expanded, new questions have arisen regarding its safety in patients with liver cirrhosis, the outcome of liver transplantation in patients with a history of bariatric surgery, and over incidental reports of liver failure following surgery. Studies in humans and rodents have also linked bariatric surgery to an increased risk of developing alcohol use disorder, a major risk factor for liver disease. This review integrates data from clinical and translational research to delineate both the beneficial impact of bariatric surgery on the liver and the potential risks involved.

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.

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

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.

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.

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.

Biliopancreatic Limb Length in One Anastomosis Gastric Bypass: Which Is the Best?

BACKGROUND

The use of one anastomosis gastric bypass (OAGB) is rapidly spreading. Concerns about biliary reflux and malabsorption with consequent nutritional deficits exist, so studies on biliopancreatic limb (BPL) adequate length in OAGB are required to balance excess weight loss in percentage (% EWL), resolution of comorbidities, and nutritional deficit. The purpose was to evaluate, at 2 years after OAGB, the effects of BPL length on weight loss, resolution of comorbidity, and nutritional deficiencies in patients.

METHODS

From January 2015 to January 2017, 180 patients were collected into three groups based BPL length: group A, 150 cm; group B, 180 cm; and group C, 200 cm. Aims were to compare %EWL, co-morbidity resolution rates, nutritional parameters, and morbidity/mortality in the three groups.

RESULTS

The total number of patients was 180: 60 for each group. One hundred seventy-two (95%) patients attended the 1-year follow-up (group A = 58; group B = 58, group C = 56). One hundred fifty-seven (87%) patients attended the 2-year follow-up (group A = 52 (87%); group B = 53 (88%); group C = 52 (87%)). There was no statistically significant difference in %EWL, %TWL, T2DM, and hypertension resolution rates among the groups. About vitamin deficiency, differences were not statistically significant. Iron and ferritin deficiency rate were statistically significant only between A and C groups.

CONCLUSIONS

According to our evidence, standardization of BPL length shorter than 200 cm is suggested, potentially minimizing malnutrition-related outcomes. Our study seems to show that a BPL of 150-180 cm is safe and effective in terms of EWL and comorbidity improvement with low malnutrition effects even in BMI > 50.

Effect of one anastomosis gastric bypass on liver function tests: A comparison between 150 cm and 200 cm biliopancreatic limbs

Context:

Some studies have shown that one anastomosis gastric bypass (OAGB) results in the derangement of liver function tests (LFTs). We wanted to study this in our patients.

Aims:

The aims are to study the effect of OAGB on LFTs and to compare the effect of a biliopancreatic limb (BPL) of 150 cm (OAGB-150) to a BPL of 200 cm (OAGB-200).

Settings and Design:

The study was a retrospective cohort study conducted at a university hospital.

Materials and Methods:

Information was obtained from our prospectively maintained database and hospital's computerised records.

Statistical Analysis:

A P < 0.05 was regarded statistically significant; however, given the number of variables examined, findings should be regarded as exploratory.

Results:

A total of 405 patients underwent an OAGB-200 (n = 234) or OAGB-150 (n = 171) in our unit between October 2012 and July 2018. There were significant improvements in gamma-glutamyl transpeptidase (GGT) levels at 1 and 2 years after OAGB-200 and significant worsening in the levels of alkaline phosphatase (ALP) and albumin at 1 and 2 years. There was a significant improvement in GGT levels at 1 and 2 years after OAGB-150 and in alanine transaminase levels at 1 year. There was a significant worsening in ALP and albumin levels at both follow-up points in this group. OAGB-150 group had a significantly lower bilirubin level at 1 year and significantly fewer abnormal ALP values at 2 years in comparison with OAGB-200 patients.

Conclusions:

This exploratory study demonstrates the overall safety of OAGB with regard to its effect on LFTs, with no remarkable difference between OAGB-150 and OAGB-200.

Nutritional consequences of bariatric surgery - prevention, detection and management

PURPOSE OF REVIEW

Bariatric surgery is an effective treatment option for severe and complex obesity; however, those who undergo such surgery need access to nutritional monitoring and vitamin and mineral supplementation to avoid the development of nutritional deficiencies.

RECENT FINDINGS

The British Obesity and Metabolic Surgery Society and the American Society for Metabolic and Bariatric Surgery have recently updated their recommendations on preoperative and postoperative nutritional monitoring and supplementation. There is a growing interest in the more malabsorptive procedures that are associated with an increased risk of nutritional deficiencies. Nutritional monitoring and prevention of nutritional deficiencies are discussed.Long-term follow-up that includes annual nutritional monitoring and access to a dietetic annual review is recommended; however, in the United Kingdom, many bariatric surgery centres are only commissioned to provide 2 years of follow-up, after which care is transferred to the general practitioner. Consideration should be given to developing shared care models for aftercare and also for the aftercare of malabsorptive procedures to remain with specialist centres.

SUMMARY

Bariatric surgery is a safe and effective treatment option for severe and complex obesity. It is essential that patients have access to lifelong nutritional monitoring adjustment of vitamin and mineral supplements to prevent nutritional issues.

Effect of One Anastomosis Gastric Bypass on Haematinics, Vitamin D and Parathyroid Hormone Levels: a Comparison Between 150 and 200 cm Bilio-Pancreatic Limbs

INTRODUCTION

There is little data on the effect of one anastomosis gastric bypass (OAGB) on haematinics, vitamin D and parathyroid hormone levels. It is further unclear if an OAGB with a bilio-pancreatic limb (BPL) of 150 cm (OAGB-150) would deliver better outcomes than that with a BPL of 200 cm (OAGB-200).

MATERIALS AND METHODS

We investigated our records to obtain information on patients who underwent an OAGB-200 or OAGB-150 until 31st July 2018 in our unit.

RESULTS

A total of 405 patients underwent either an OAGB-200 (n = 234) or OAGB-150 (n = 171). The mean age was 46 ± 10.98 years and 276 (68.1%) were females. The mean preoperative weight and the body mass index (BMI) were 139 ± 29.96 kg and 49 ± 8.14 kg/m² respectively. With OAGB-200, there was a significant increase in anaemia rates at 1 and 2 years compared to preoperative levels with a significant fall in haemoglobin levels. After OAGB-150, there was a significant fall in haemoglobin levels at 1 and 2 years but the increase in anaemia rate was only significant at 2 years. There was a significant increase in PTH levels and the number of abnormal values at 1 and 2 years with OAGB-200. With OAGB-150, PTH changes were significant at 2 years only.

CONCLUSION

We found that both OAGB-200 and OAGB-150 are associated with a significant increase in anaemia and secondary hyperparathyroidism. Our findings should prompt the evaluation of supplementation protocols with higher dosages than we recommend for iron, folate and calcium. Consideration should also be given to evaluating shorter BPL lengths than 150 cm with OAGB.

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.

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 after Sleeve Gastrectomy Failure: Does a Single Procedure Fit for all?

INTRODUCTION

Considering the multitude of bariatric procedures performed all over the world, the necessity of revisional surgery increased accordingly. Several authors argued that with the great diffusion of sleeve gastrectomy (SG), the number of patients who experienced a weight regain at long follow-up was congruous and physiologic, even if not negligible. Recent studies showed that one anastomosis gastric bypass (OAGB) was an effective and safe option also as redo surgery. The aim of the study was to evaluate effectiveness of OAGB as redo surgery after SG in term of anthropometric features and remission of comorbidities.

METHODS

Bariatric patients experiencing weight regain and insufficient weight loss after SG and undergoing OAGB as redo surgery were retrospectively analyzed. During post-OAGB outpatient visit weight, %EWL, BMI, comorbidities, and vitamin deficiencies were evaluated. A further visit was scheduled for the evaluation of postoperative esophagitis/gastritis at upper endoscopy.

RESULTS

Fifty-nine (Reviewer #3-1) patients underwent OAGB as redo-surgery consequently to the worsening of the bariatric outcomes at 29.42 ± 7.29 months from SG (mean weight, BMI and %EWL were 120.89 ± 16.79 kg, 43 ± 4.39 and 19.84 ± 30.29, respectively). Conversely, at a mean follow-up of 34.32 ± 1.71 months (Reviewer #3-3) after OAGB, no weight regain or insufficient weight loss cases were recorded (mean weight 71.25 ± 10.22 kg, mean BMI 24.46 ± 2.06 kg/m2, mean %EWL 69.49 ± 14.4, p < 0.0001) (Reviewer #3-2).

CONCLUSION

OAGB is a safe and effective bariatric procedure in terms of morbidity, mortality, and %EWL also as revision surgery after SG. Further larger studies are needed to address this issue.

Case Report: Extensive Dermatitis Secondary to Severe Malnutrition, Zinc and Vitamin Deficiencies After Malabsorptive Bariatric Surgery

Bariatric surgery is one of the most effective treatments currently available for obesity and its derived comorbidities. However, complications may occur, especially when malabsorptive surgeries like a biliopancreatic diversion is performed. We present the case of a female patient whose obesity was treated with this technique, and in the 9^th year of follow-up developed an extensive dermatitis secondary to zinc deficiency and malnutrition, precipitated by therapeutic non-compliance. A close surveillance of early symptoms and signs of nutritional deficiencies as well as chronic supplementation of vitamins and trace elements is required; this case illustrates the relevance of periodical, lifelong visits to a medical physician with special training and experience in the management of post bariatric surgery patients in order to prevent, diagnosis and early treat related complications.