Length of biliopancreatic limb in Roux-en-Y gastric bypass and its impact on post-operative outcomes in metabolic and obesity surgery-systematic review and meta-analysis

Enhanced Total Weight Loss 2 Years Post-Roux-en-Y Gastric Bypass with Longer Biliopancreatic Limb

BACKGROUND

Despite widespread use of Roux-en-Y gastric bypass (RYGB), there are no standardized limb lengths in the United States.

METHODS

A multi-center retrospective cohort study was conducted from 2020 to 2023. Eligible patients who had undergone RYGB were divided into subgroups based on BP limb lengths: short (50-75 cm), intermediate (80-125 cm), and long (150-175 cm). Primary outcomes were total weight loss (TWL) and % TWL at 1 and 2 years. Secondary outcomes were post-operative BMI and % BMI change at 1 and 2 years, micronutrient deficiencies, hypothyroidism, acute kidney injury (AKI) requiring treatment, and remission in associated medical problems. Subgroups were compared using multivariate analysis.

RESULTS

Two hundred twenty-eight patients received a long BP limb, 194 patients received an intermediate BP limb, while 152 patients received a short BP limb. Primary outcomes TWL and % TWL were significantly different between the groups at 1 year: TWL and % TWL were greater in patients with long BP limbs. The difference between the long and short BP limb groups increased at the 2-year mark. Patients who had long BP limbs had higher rates of DM remission (12.3% vs 11.9% 6.6%), HTN (8.8% vs 5.7% vs 7.9%), GERD symptoms (14.5% vs 9.8% vs 5.3%), and OSA (8.8% vs 7.7% vs 5.3%). Vitamin A deficiency rates were higher in the long BP limb group.

CONCLUSIONS

The results suggest that longer BP limb lengths are conducive to TWL and overall treatment of obesity-related problems without severe rates of complications. Additional longer longitudinal studies are needed to assess the impact of long BP limbs on nutrition and weight loss in the long term.

Persistent Gastroesophageal Reflux Disease After RYGB: What Shall we do Next?

BACKGROUND

Roux-en-Y gastric bypass (RYGB) is considered the weight loss procedure of choice for obese patients with gastroesophageal reflux disease (GORD). The long-term prevalence of GORD after RYGB for obesity is underestimated as many post-RYGB patients can still complain of severe reflux symptoms, refractory to medications.

METHODS

This is a narrative review using the patient, intervention, comparison, outcome and study strategy. The literature search was undertaken using PubMed, Medline, and Google Scholar databases with the following MeSH terms: Gastroesophageal reflux disease, GORD, Obesity, Gastric bypass, Roux-en-Y gastric bypass, complication, and fundoplication.

RESULTS

Twelve original papers and case report studies on 57 patients who met the inclusion criteria were suitable for the present review. Reporting styles on successful treatment outcomes were heterogeneous. Treatment options for these patients are limited but include further surgical or endoscopic interventions. Careful follow-up and appropriate management are paramount for this population.

CONCLUSION

There is significant paucity in the available evidence on managing GORD after RYGB. This narrative review provides a detailed overview of the underlying causes, discusses the various endoscopic and surgical therapy options, and suggests strategies to provide tailored and appropriate therapy for this complex group of patients.

Dietary Habits, Obesity, and Bariatric Surgery: A Review of Impact and Interventions

Eating behavior encompasses the psychological, physiological, and environmental factors influencing food intake. Dysregulation in eating behavior, such as emotional eating, binge eating, or loss of satiety signals, contributes to excessive caloric intake and weight gain. These behaviors are often linked to hormonal imbalances, stress, or genetic predisposition. Obesity is a chronic, multifactorial disease characterized by excessive body fat accumulation, with a body mass index (BMI) ≥ 30 kg/m2 often used for diagnosis. It is associated with significant morbidity, including type 2 diabetes, cardiovascular disease, and obstructive sleep apnea. Pathophysiological mechanisms underlying obesity include insulin resistance, leptin dysregulation, and altered gut microbiota, which perpetuate metabolic derangements. Lifestyle interventions remain first-line treatment, but sustained weight loss is challenging for many patients. Bariatric surgery is a therapeutic option for individuals with severe obesity (BMI ≥ 40 kg/m2 or ≥35 kg/m2 with comorbidities) who have failed conservative management. Procedures such as Roux-en-Y gastric bypass and sleeve gastrectomy alter gastrointestinal anatomy, promoting weight loss through restriction, malabsorption, and hormonal modulation (e.g., increased GLP-1 secretion). Bariatric surgery improves obesity-related comorbidities and enhances quality of life. However, it requires lifelong medical follow-up to address potential nutritional deficiencies and ensure sustainable outcomes.

Comparative Effects of Sleeve Gastrectomy vs. Roux-en-Y Gastric Bypass on Phase Angle and Bioelectrical Impedance Analysis Measures: A Systematic Review and Meta-Analysis

Background/Objectives: The objective of this meta-analysis was to determine the impact of bariatric surgery on phase angle (PhA) and other bioimpedance measures among adults with obesity, comparing the effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines, including studies up to May 2024 from MEDLINE, Scopus, Cochrane Library, and Web of Science. Eligible studies assessed PhA changes pre- and post-bariatric surgery in adults with BMI ≥ 30 kg/m2. Data on PhA, fat mass (FM), fat-free mass (FFM), body cell mass (BCM), weight, and BMI were extracted and analyzed. Results: Thirteen studies with a total of 1124 patients were included. Significant PhA reductions were observed at 6 months post-surgery (effect size: -1.00; 95% CI: -1.11 to -0.89; p < 0.001), with a more substantial reduction in RYGB patients compared to SG. FM and FFM decreased significantly at 12 months (FM: -27.58; 95% CI: -32.58 to -22.57; p < 0.001; FFM: -10.51; 95% CI: -12.81 to -8.94; p < 0.001). Weight and BMI showed marked reductions at 6 months (Weight: -31.42 kg; 95% CI: -37.28 to -25.26; p < 0.001; BMI: -11.39; 95% CI: -12.60 to -10.18; p < 0.001), with sustained decreases at 12 and 24 months. Conclusions: Bariatric surgery significantly reduces PhA, FM, FFM, weight, and BMI, with initial greater impacts observed in RYGB compared to SG. PhA shows potential as a marker for monitoring post-surgical recovery and nutritional status. Further long-term studies and standardized measurement protocols are recommended to optimize patient management.

The Impact of Bariatric Surgery on Type 2 Diabetes Mellitus Remission: A Systematic Review

Bariatric surgery has been shown to significantly affect type 2 diabetes mellitus (T2DM) remission, particularly in obese individuals. This systematic review aims to evaluate the effectiveness of bariatric surgical interventions in inducing remission of T2DM as well as to identify factors influencing surgical outcomes. The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive literature search was performed across multiple databases, including PubMed, Embase, and Cochrane Library, utilizing text words and controlled vocabulary in various combinations with Boolean operators "AND" and "OR." The search was limited to open-access, full-text articles in English published from 2005 to 2024, including studies involving human subjects. The quality of the included studies was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. In the study selection process for the systematic review, records were initially identified from three databases: Cochrane (31 records), Embase (62 records), and PubMed (52 records). This yielded 145 records. After removing 107 records, 38 records remained for screening. Of these, five records were excluded based on irrelevant problems and irrelevant outcomes. Subsequently, 33 reports were sought for full-text retrieval, with all reports being retrievable. The 33 reports were assessed for eligibility. Out of these, six were excluded due to an inaccessible full-text record. Finally, 33 studies met the inclusion criteria and were included in the review. Bariatric surgery is a highly effective intervention for individuals with T2DM, particularly those with obesity. It leads to significant weight loss and improved glycemic control through mechanisms that reduce stomach size and alter hormonal responses. This surgery not only helps many patients achieve remission from diabetes but also decreases the risk of obesity-related health issues. Beyond physical health, patients often report enhanced psychological well-being and quality of life. Overall, bariatric surgery can transform the health trajectory of select individuals, offering them a renewed sense of control and improved overall health.

Does the length of bypassed bowel during distal gastric bypass affect weight loss?

INTRODUCTION

Weight recurrence (WR) affects > 20% of patients following Roux-en-Y gastric bypass (RYGB). Shortening of the common channel (CC) after RYGB (distal bypass) has been proposed for additional weight loss in patients with WR, but results vary, and concerns for vitamin deficiencies/malnutrition exist. Our aim was to determine whether the percentage of bowel bypassed after distal bypass is associated with the amount of postoperative weight loss.

METHODS

Patients undergoing distal bypass between 2018 and 2022 were reviewed. Small bowel limb lengths before and after distal bypass were measured, and the percentage of bypassed bowel was calculated (= bypassed biliopancreatic limb/total small bowel length). Patients were dichotomized into two groups based on the percentage bypassed bowel (≤ 50% vs. > 50%). Weight loss (measured as excess BMI loss; EBIL%), comorbidities resolution, complications, and nutritional deficiencies were reviewed.

RESULTS

Thirty female patients underwent distal bypass during the study period. After distal bypass, the Roux was lengthened to 150 cm (75-175 cm) from 75 cm (20-200 cm), and the CC shortened to 150 cm (100-310 cm) from 510 cm (250-1000 cm). These changes resulted in an increase in the size of the bypassed biliopancreatic limb from 40 cm (15-90 cm) to 330 cm (180-765 cm) and a total alimentary limb (TALL; Roux + CC) shortening from 590 cm (400-1075 cm) to 300 cm (250-400 cm). The group with > 50% bowel bypassed had higher EBIL%. Overall EBIL% was 36.9 ± 14.7%, 53.3 ± 25.6%, and 62.1 ± 36.9% at 0.5, 1, and 2 years, respectively. There were minimal vitamin deficiencies. Diabetes resolved in 100% (n = 3/3), HTN in 67% (n = 10/15), and GERD in 73% (n = 11/15). Complication rate was 23%. No reintervention for malnutrition or vitamin deficiencies was required.

CONCLUSIONS

Distal bypass effectively leads to considerable weight loss and comorbidity improvement in patients with WR after RYGB, but the amount of weight loss depends on the percentage of bypassed bowel. An exact threshold of bypassed bowel that optimizes weight loss outcomes and simultaneously minimizes the nutritional complications needs to be determined. Meanwhile, close monitoring for vitamin deficiencies is recommended.

Laparoscopic small bowel length measurement: nonassociative nature of total small bowel length with anthropometric and clinical characteristics in patients undergoing bariatric surgery

BACKGROUND

Small bowel length (SBL) may have an impact on the outcomes of bariatric surgeries, but it can be difficult to make a direct association between SBL and the safety and outcome of bariatric surgeries.

OBJECTIVES

To address this issue, we set out to devise a predictive model for SBL determination based on clinical and anthropometric variables.

SETTING

An academic tertiary medical center.

METHODS

Anthropometric and clinical data, including age, sex, height, weight, and past medical history, were collected upon enrollment. SBL was measured twice during the surgery using a marked grasper. In all cases, measurements were carried out by a single surgeon. To create a predictive model, a 2-step approach was employed. In the first step, linear regression was used to determine influential variables. In the second step, all variables with a P value < .2 were entered into a multivariate regression model.

RESULTS

Overall, 961 bariatric candidates were enrolled. The mean age of the participants was 40.08 years, and 77.5% (n = 745) were female. The mean SBL was 748.90 centimeters. There was a weak but statistically significant positive correlation between SBL with both weight and height. Our univariate linear model determined only anthropometric parameters as a predictor of SBL. The multivariate model also yielded that none of the entered parameters were shown to be accurate predictors of SBL. Moreover, only 4.3% of variances were explainable by this model.

CONCLUSION

Although we found a weak positive association between height and SBL, this association lacked clinical practicality.

The Impact of Longer Biliopancreatic Limb Length on Weight Loss and Comorbidity Improvement at 5 Years After Primary Roux-en-Y Gastric Bypass Surgery: A Population-Based Matched Cohort Study

INTRODUCTION

Different limb lengths are used in Roux-en-Y gastric bypass (RYGB) surgery, as there is no consensus which limb length strategy has the best outcomes. The biliopancreatic limb (BPL) is thought to play an important role in achieving weight loss and associated comorbidity resolution. The objective of this study was to assess the impact of a longer BPL on weight loss and comorbidity improvement at 5 years after primary RYGB.

METHODS

All patients aged ≥ 18 years undergoing primary RYGB between 2014-2017 with registered follow-up 5 years after surgery were included. Long BPL was defined as BPL ≥ 100 cm and short BPL as BPL < 100 cm. The primary outcome was achieving at least 25% total weight loss (TWL) at 5 years. Secondary outcomes included absolute %TWL and improvement of comorbidities. A propensity score matched logistic and linear regression was used to estimate the difference in outcomes between patients with long and short BPL.

RESULTS

At 5 years, long BPL had higher odds to achieve ≥ 25% TWL (odds ratio (OR) 1.19, 95% confidence interval (CI) [1.01 - 1.41]) and was associated with 1.26% higher absolute TWL (β = 1.26, 95% CI [0.53 - 1.99]). Furthermore, long BPL was more likely to result in improved diabetes mellitus (OR = 2.17, 95% CI [1.31 - 3.60]) and hypertension (OR = 1.45, 95% CI [1.06 - 1.99]).

CONCLUSION

Patients undergoing RYGB with longer BPL achieved higher weight loss and were more likely to achieve improvement of comorbidities at 5 years.

Pharmacotherapy as an Augmentation to Bariatric Surgery for Obesity

A global obesity pandemic is one of the most significant health threats worldwide owing to its close association with numerous comorbidities such as type 2 diabetes mellitus, arterial hypertension, dyslipidemia, heart failure, cancer and many others. Obesity and its comorbidities lead to a higher rate of cardiovascular complications, heart failure and increased cardiovascular and overall mortality. Bariatric surgery is at present the most potent therapy for obesity, inducing a significant weight loss in the majority of patients. In the long-term, a substantial proportion of patients after bariatric surgery experience a gradual weight regain that may, in some, reach up to a presurgical body weight. As a result, anti-obesity pharmacotherapy may be needed in some patients after bariatric surgery to prevent the weight regain or to further potentiate weight loss. This article provides an overview of the use of anti-obesity medications as an augmentation to bariatric surgery for obesity. Despite relatively limited published data, it can be concluded that anti-obesity medication can serve as an effective adjunct therapy to bariatric surgery to help boost post-bariatric weight loss or prevent weight regain.

Impact of Gastrojejunostomy Anastomosis Diameter on Weight Loss Following Laparoscopic Gastric Bypass: A Systematic Review

Laparoscopic Roux-en-Y gastric bypass (RYGB) is crucial for significant weight reduction and treating obesity-related issues. However, the impact of gastrojejunostomy (GJ) anastomosis diameter on weight loss remains unclear. We investigate this influence on post-RYGB weight loss outcomes. A systematic search was conducted. Six studies met the inclusion criteria, showing varied GJ diameters and follow-up durations (1-5 years). Smaller GJ diameters generally correlated with greater short-to-medium-term weight loss, with a threshold beyond which complications like stenosis increased. Studies had moderate-to-low bias risk, emphasizing the need for precise GJ area quantification post-operation. This review highlights a negative association between smaller GJ diameters and post-RYGB weight loss, advocating for standardized measurement techniques. Future research should explore intra-operative and AI-driven methods for optimizing GJ diameter determination.

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.

Outcomes of One-Anastomosis Gastric Bypass Conversion to Roux-en-Y Gastric Bypass for Severe Obesity: A Systematic Review and Meta-analysis

One-anastomosis gastric bypass (OAGB) is an effective procedure to treat severe obesity. However, conversion to Roux-en-Y gastric bypass (RYGB) is increasing. We therefore conducted a systematic review to determine the safety and efficacy associated with OAGB-RYGB conversion. A systematic search was conducted by three independent reviewers using Medline, Embase, and the Cochrane library following PRISMA guidelines. Six studies including 134 patients were selected who were undergoing OAGB-RYGB conversion. The most common indications were reflux (47.8%), malnutrition (31.3%), and inadequate weight loss (8.2%). Study outcomes demonstrated 100% resolution of bile reflux. Overall, there was medium-term weight gain of 0.61 BMI. OAGB to RYGB conversion leads to resolution of reflux symptoms. However, it is associated with weight regain, albeit this may be acceptable to patients to treat biliary reflux.

Barriers to metabolic surgery and how to address them

After bariatric surgery, patients with obesity achieve sustainable weight loss, gain in mobility, quality of life and life expectancy. Bariatric surgery can lead to remission of type 2 diabetes or to long term glycaemic control for patients with type 2 diabetes, while medical treatment has a preventive efficacy on micro and macrovascular complications. This has led to the concept of metabolic surgery to treat type 2 diabetes. Despite the benefits, only a small proportion of eligible patients undergo bariatric/metabolic surgery. Powerful antidiabetic medications, self-estimated lack of knowledge by medical professionals and fear of surgical complications are some of the arguments to prefer medical treatment of type 2 diabetes obesity versus metabolic surgery. We have reviewed in this paper the barriers which explain the low referral rate to metabolic surgery. With the point of view of the diabetologist, the general practitioner and the patient, we have addressed them to help clinicians and patients model an evidenced-based patient-oriented medical plan.

Optimal Small Bowel Limb Lengths of Roux-en-Y Gastric Bypass

PURPOSE OF REVIEW

Gastric bypass and biliopancreatic diversion (BPD) have come full circle, from a loop configuration to a Roux-en-Y and finally back to a loop configuration as one anastomosis gastric bypass and single-anastomosis duodenal switch. Most surgeons performing Roux-en-Y gastric bypass (RYGB) do not measure the common channel (CC) length and most surgeons performing BPD do not measure the biliopancreatic limb length (BPL).

RECENT FINDINGS

The small bowel length in humans is variable from as short as < 400 cm to as long as > 1000 cm. The combination of these two facts means that even if surgeons keep the limb lengths constant, surgeons will get variable limb length due to the variability of small bowel length in patients. Hence, outcomes of weight loss, resolution of medical problems, or developing nutritional deficiencies which are related to limb length are variable. In this article, we evaluate the published literature related to the effect of varying the Roux limb, BPL, CC, and total alimentary limb lengths on the outcomes of RYGB. We have focused on historical and current randomized controlled trials as well as systematic reviews and meta-analysis to outline the current literature and our interpretation of this literature.

Do all roads lead to Rome?: A retrospective analysis on surgical technique in Roux-en-Y gastric bypass

BACKGROUND

New York University Langone Health has three accredited bariatric centers, with altogether ten different bariatric surgeons. This retrospective analysis compares individual surgeon techniques in laparoscopic or robotic Roux-en-Y gastric bypass (RYGB) to identify potential associations with perioperative morbidity and mortality.

METHODS

All adult patients who underwent RYGB between 2017 and 2021 at NYU Langone Health campuses were evaluated via electronic medical records and MBSAQIP 30-day follow-up data. We surveyed all ten practicing bariatric surgeons to analyze the relationship between their techniques and total adverse outcomes. Bleeding, SSI, mortality, readmission, and reoperation were specifically sub-analyzed via logistic regression.

RESULTS

54 (7.59%) out of 711 patients who underwent laparoscopic or robotic RYGB encountered an adverse outcome. Lower adverse outcomes were observed with laparoscopic approach, creating the JJ anastomosis first, flat positioning, division of the mesentery, Covidien™ laparoscopic staplers, gold staples, unidirectional JJ anastomosis, hand-sewn common enterotomy, 100-cm Roux limb, 50-cm biliopancreatic limb, and routine EGD. Lower bleeding rates were observed with flat positioning, gold staples, hand-sewn common enterotomy, 50-cm biliopancreatic limb, and routine EGD. Lower readmission rates were observed in laparoscopic, flat positioning, Covidien™ staplers, unidirectional JJ anastomosis, and hand-sewn common enterotomy. Gold staples had lower reoperation rates. Otherwise, there was no statistically significant difference in SSI.

CONCLUSION

Certain surgical techniques in RYGB within our bariatric surgery group had significant effects on the rates of total adverse outcomes, bleeding, readmission, and reoperation. Our findings warrant further investigation into the aforementioned techniques via multivariate regression models or prospective study design.

LIMITATIONS

This study was limited by the inherent nature of its retrospective and univariate statistical design. We did not account for the interaction between techniques. The sample size of surgeons was small, and follow-up of 30 days was relatively short. We did not include patient characteristics in the model or control for surgeon skill.

The surgical management of obesity

Obesity has reached pandemic levels globally. Surgical management of obesity aims to establish metabolic control, weight loss and resolution of multiple health conditions and to improve quality of life. Here, we examine the role of surgery in the management of obesity within the context of a multidisciplinary team involving a variety of healthcare professionals. We highlight the importance of patient selection, perioperative care, the various types of bariatric surgery currently available as well as emerging procedures. In addition to clarifying the different types of procedure, we also examine the potential complications and issues of weight regain and failure to lose weight. Ultimately, bariatric surgery remains comparatively safe and with generally excellent results in terms of control of existing obesity-related conditions; with the ever-increasing number of patients living with obesity, the scope of bariatric surgery is thus likely to increase.