Impact of limb length on nutritional status in one-anastomosis gastric bypass: 3-year results

EFFICACY AND SAFETY OF ONE ANASTOMOSIS GASTRIC BYPASS IN SURGICAL TREATMENT OF OBESITY: SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

BACKGROUND

One anastomosis gastric bypass (OAGB) has gained prominence in the search for better results in bariatric surgery. However, its efficacy and safety compared to Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) remain ill-defined.

AIMS

To compare the efficacy and safety of OAGB relative to RYGB and SG in the treatment of obesity.

METHODS

We systematically searched PubMed, EMBASE, Cochrane Library, Lilacs, and Google Scholar databases for randomized controlled trials comparing OAGB with RYGB or SG in the surgical approach to obesity. We pooled outcomes for body mass index, percentage of excess weight loss, type-2 diabetes mellitus remission, complications, and gastroesophageal reflux disease. Statistical analyses were performed with R software (version 4.2.3).

RESULTS

Data on 854 patients were extracted from 11 randomized controlled trials, of which 422 (49.4%) were submitted to OAGB with mean follow-up ranging from six months to five years. The meta-analysis revealed a significantly higher percentage of excess weight loss at 1-year follow-up and a significantly lower body mass index at 5-year follow-up in OAGB patients. Conversely, rates of type-2 diabetes mellitus remission, complications, and gastroesophageal reflux disease were not significantly different between groups. The overall quality of evidence was considered very low.

CONCLUSIONS

Our results corroborate the comparable efficacy of OAGB in relation to RYGB and SG in the treatment of obesity, maintaining no significant differences in type-2 diabetes mellitus remission, complications, and gastroesophageal reflux disease rates.

Reduction in Serum Carotenoid Levels Following One Anastomosis Gastric Bypass

Given the health benefits of carotenoids, it is crucial to evaluate their levels in patients undergoing malabsorptive procedures like one anastomosis gastric bypass (OAGB). This study aimed to assess serum carotenoid levels before and 6 months following OAGB. Prospectively collected data from patients who underwent primary OAGB were analyzed. Data included anthropometrics, dietary intake assessments, and biochemical tests. Serum samples were analyzed for lipid profile and serum carotenoids, including lutein, zeaxanthin, α-carotene, β-carotene, phytofluene, ζ-carotene, and lycopene. Data from 27 patients (median age 47.0 years and 55.6% female) were available before and 6 months post-OAGB. The median pre-surgical BMI was 39.5 kg/m2, and the median excess weight loss at 6 months post-surgery was 63.9%. Significant decreases in all carotenoid levels were observed over time (p < 0.001 for all). A median relative decline of 65.1% in absolute total carotenoid levels and 12.7% in total cholesterol levels were found. No associations were observed between changes in clinical outcomes and carotenoid levels during the study period. This study reveals significant decreases in carotenoid levels within the first 6 months following OAGB. Nutritional intervention studies are needed to explore how incorporating carotenoid-rich foods affects post-surgery carotenoid levels and clinical outcomes.

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.

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

OBJECTIVE

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.

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.

Nutritional and Lifestyle Behaviors Reported Following One Anastomosis Gastric Bypass Based on a Multicenter Study

This study aimed to describe nutritional and lifestyle parameters following one-anastomosis gastric bypass (OAGB). A multicenter study among OAGB patients across Israel (n = 277) and Portugal (n = 111) was performed. Patients were approached according to the time elapsed since surgery. An online survey with information regarding demographics, anthropometrics, and nutritional and lifestyle aspects was administered in both countries simultaneously. Respondents from Israel (pre-surgery age of 41.6 ± 11.0 years, 75.8% females) and Portugal (pre-surgery age of 45.6 ± 12.3 years, 79.3% females) reported changes in their appetite (≤94.0% and ≤94.6%), changes in their taste (≤51.0 and ≤51.4%), and intolerance to specific foods (i.e., red meat, pasta, bread, and rice). Bariatric surgery-related eating recommendations were generally followed well, but a trend toward lower adherence was evident in groups with longer time elapsed since surgery in both countries. Most respondents from Israel and Portugal reported participation in follow-up meetings with a surgeon (≤94.0% and 100%) and a dietitian (≤92.6% and ≤100%), while far fewer reported participation in any follow-up meeting with a psychologist/social worker (≤37.9% and ≤56.1%). Patients following OAGB might experience changes in appetite, taste, and intolerance to specific foods. Adherence to bariatric surgery-related eating recommendations is not always satisfying, especially in the longer term post-surgery.

Nutritional Status after Roux-En-Y (Rygb) and One Anastomosis Gastric Bypass (Oagb) at 6-Month Follow-Up: A Comparative Study

Introduction: Roux-en-Y gastric bypass (RYGB) and one anastomosis gastric bypass (OAGB) are two effective bariatric surgical procedures with positive outcomes in terms of weight loss, comorbidities remission, and adverse events profiles. OAGB seems to carry a higher risk of malnutrition, but existing data are controversial. The aim of this study is to objectively evaluate and compare malnutrition in patients undergoing RYGB and OAGB. Methods: Retrospective monocentric study of obese patients undergoing RYGB or OAGB between the 15 September 2020 and the 31 May 2021. Nutritional status was assessed using the Controlling Nutritional Status (CONUT) score and compared between groups. The primary outcome was the mean CONUT score at 6 months. The secondary outcomes included the incidence of malnutrition, comorbidities, including hypertension, insulin resistance and type II diabetes mellitus, and weight loss. Results: 78 patients were included: 30 underwent RYGB and 48 underwent OAGB. At 6-Month Follow-Up there was no difference between groups in the mean CONUT score nor in incidence of malnutrition. In both groups, the nutritional status significantly worsened 6 months after surgery (preoperative and postoperative score of 0.48 ± 0.9 and 1.38 ± 1.5; p = 0.0066 for RYGB and of 0.86 ± 1.5 and 1.45 ± 1.3; p = 0.0422 for OAGB). Type II Diabetes mellitus (DMII) and hypertension remission were significant in the OAGB group with a 100% relative remission in the DMII-OAGB group (p = 0.0265), and a 67% relative remission in the hypertension-OAGB group (p = 0.0031). Conclusions: No difference in nutritional status has been detected between patients undergoing RYGB or OAGB at the 6-Month Follow-Up. Both procedures may have significant mal-absorptive effects leading to decline in nutritional status. OAGB may be more efficacious in inducing DMII and hypertension remission. Larger prospective studies dedicated specifically to nutritional status after gastric bypass are needed to confirm the impact of different bypass procedures on nutritional status.

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.

Anemia After Sleeve Gastrectomy and One-Anastomosis Gastric Bypass: An Investigation Based on the Tehran Obesity Treatment Study (TOTS)

BACKGROUND

Bariatric surgery has been associated with iron, folate, and vitamin B12 deficiencies, which can lead to anemia. This study compares the incidence of anemia between sleeve gastrectomy (SG) and one-anastomosis gastric bypass (OAGB).

METHODS

Patients from a prospectively collected database of patients with morbid obesity undergoing a primary bariatric procedure from April 2013 to September 2018 were included. Statistical analysis was performed using the general estimation equation. Patients were followed for 6, 12, 24, and 36 months post-surgery.

RESULTS

The present study included 2618 patients, of whom 72.3% underwent SG and 27.6% underwent OAGB. The majority of the study population were women (75.7%), and the mean age of the participants was 39.5 ± 11.7 years. At the end of the follow-up, the excess weight loss percentage was 66.15 in the SG group and 75.41 in the OAGB group (P <  0.05). The incidence of anemia at 12-, 24-, and 36-month was 16.2, 19.7, and 24.3% in the SG group and 28.4, 37.6, and 56.5% in the OAGB group, showing significantly higher incidence in the OAGB than the SG group ([Formula: see text] < 0.001). However, there was no significant difference between the SG and OAGB groups regarding the incidence of iron and vitamin B12 deficiency.

CONCLUSIONS

The patients undergoing bariatric surgery, especially OAGB, should be closely monitored post-surgery regarding the incidence of anemia, and supplementation in developing countries could be continued even after the first year.

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.

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.

Psychopharmacological Medication Has No Influence on Vitamin Status After Bariatric Surgery in Long-term Follow-up

Context

A substantial number of patients undergoing bariatric surgery are prescribed psychopharmacological medication. However, the impact of concomitant psychopharmacological medication on the frequency of relevant vitamin deficiencies in postoperative follow-up is not known.

Methods

Five hundred twenty-four patients with obesity who underwent bariatric surgery (January 2004 to September 2018) with follow-up of at least 12 months, were included in retrospective analysis. Postoperative follow-up visits between January 2015 and September 2019 were analyzed. Anthropometric and laboratory data were analyzed at the first documented follow-up visit after on average 39.5 ± 37.3 months and at every following visit during the observation period. Patients with prescribed psychopharmacological drugs (PD) were compared with patients without (control group, CON).

Results

Psychopharmacological medication was documented in 25% (132) of patients. In 59 patients documented prescription of more than one psychiatric drug was found, whereas psychopharmacological monotherapy was found in 73 patients. Frequencies of vitamin deficiencies were comparable between PD and CON (vitamin A: p = 0.852; vitamin D: p = 0.622; vitamin E: p = 0.901; folic acid: p = 0.941). Prevalence of vitamin B₁₂ deficiency was rare (6% CON, 1% PD) but was significantly higher in CON (p = 0.023). A comparison of CON and POLY also showed no significant differences between the groups concerning prevalence of vitamin deficiencies.

Conclusions

Intake of psychopharmacological medication is highly prevalent in patients after bariatric surgery. Patients with psychopharmacological medication, who participate in structured follow-up care after bariatric surgery, are not at higher risk for vitamin deficiencies compared with controls.