American Society for Metabolic and Bariatric Surgery review of the literature on one-anastomosis gastric bypass

Similar Rates of Symptomatic Marginal Ulcers After One-Anastomosis-Gastric Bypass Compared to Roux-en-Y Gastric Bypass

PURPOSE

One-anastomosis-gastric-bypass (OAGB) has become a common bariatric procedure worldwide. Marginal ulcers (MU) are a significant non-immediate complication of gastric bypass surgeries. There seems to be concern among surgeons that MU are more common after OAGB compared with Roux-en-Y gastric bypass (RYGB) due to the constant and extensive exposure of the anastomosis to bile. The aim of this study was to compare the incidence, presentation, and management of MU between the two surgeries.

MATERIALS AND METHODS

A retrospective study of prospectively collected data was performed to include all consecutive patients between 2010 and 2020, who underwent elective OAGB or RYGB at our institution. Patients diagnosed with symptomatic MU were identified. Factors associated with this complication were assessed and compared between the two surgeries.

RESULTS

Symptomatic MU were identified in 23/372 OAGB patients (6.2%) and 35/491 RYGB patients (7.1%) (p = 0.58). Time to ulcer diagnosis was shorter in OAGB patients (12 ± 11 vs. 22 ± 17 months, p < 0.01). Epigastric pain was the common symptom (78% OAGB vs. 88.5% RYGB, p = 0.7) and approximately 15% of ulcers presented with perforation upon admission (17% vs.11.4%, p = 0.7). Re-operation was required in 5/23 OAGB (21.7%) and 6/36 RYGB (17%) patients (p = 0.11) while the rest of the patients were managed non-operatively.

CONCLUSIONS

The risk of developing a marginal ulcer is similar between patients who underwent OAGB and RYGB. Patients diagnosed with MU following OAGB tend to present earlier; however, the clinical presentation is similar to RYGB patients. The management of this serious complication seems to be associated with acceptable outcomes with comparable operative and non-operative approaches.

Early safety outcomes of laparoscopic one anastomosis gastric bypass in patients with class III, IV, and V obesity

BACKGROUND

The extremely obese patient deserves special consideration: significant comorbidities, technical difficulties, and increased postoperative morbidity and mortality are all expected in this patient population. The study compared early postoperative complications (≤30-day) following one-anastomosis gastric bypass (OAGB) morbidity in patients with morbid obesity class IV obesity, body mass index (BMI) ≥50-59.9 kg/m2, and class V obesity, BMI ≥60 patients.

METHODS

We retrospectively reviewed perioperative OAGB outcomes in three BMI groups. Operative time, length of stay (LOS), and overall early postoperative complication rates were studied. Patient-reported complications were ranked by Clavien-Dindo Classification (CDC).

RESULTS

Between January 2017-December 2021, consecutive patients with obesity class III (n = 2950), IV (n = 256), and V (n = 23) underwent OAGB. BMI groups were comparable in sex, age, and associated comorbidities. Mean operative time was significantly longer in the higher BMI groups: class III (66.5 ± 25.6 min), IV (70.5 ± 28.7 min), and V (80.0 ± 34.7 min), respectively (p = 0.018); no difference in LOS. In respective BMI classes, ≤30-day complication rates were 3.2%, 3.5%, and 4.3% (p = 0.926). The respective number of patients with CDC grades of one to two were 45 (1.5%), 6 (2.3%), and 1 (4.3%), p = 0.500; and in grade ≥3a, 25 (0.8%), 1 (0.4%), 0 (0.0%), p = 0.669. There was 0.06% mortality (n = 2 in 3229), both in BMI class III.

CONCLUSIONS

OAGB is a safe BS procedure in patients with class III, IV, and V obesity in the perioperative term with comparable ≤30-day morbidity in the three BMI groups.

Banded One-Anastomosis Gastric Bypass (BOAGB) for Patients Living with Obesity and Extreme Obesity: A Single Institution's Experience

BACKGROUND

The prevalence of patients suffering from extreme obesity (body mass index (BMI) ≥ 50) has significantly increased over the past three decades, surpassing the rise in the general population of overweight patients. Weight loss outcomes after bariatric surgery in patients suffering from extreme obesity are less favorable, with a higher incidence of weight regain. Variations of existing bariatric procedures have been proposed to address this issue. One such variation is adding a gastric band to limit the expansion of the newly created pouch. Limited data exist regarding the effectiveness of this procedure, called the banded one-anastomosis gastric bypass (BOAGB) procedure, compared to other bariatric procedures.

METHOD

In this retrospective study, we compared all patients who underwent the BOAGB procedure at the Bariatric Surgery Unit in our Medical Center with a postoperative follow-up of at least 1 year with patients who underwent a one-anastomosis gastric bypass (OAGB) or sleeve gastrectomy (SG) procedures. Data collected included demographics, comorbidities, surgical outcomes, complications, and postoperative quality-of-life assessments.

RESULTS

One hundred eleven patients were enlisted to our study during the relevant study period-24 patients underwent the BOAGB procedure, 43 underwent OAGB, and 44 underwent a SG. Lost to follow-up beyond 30 days was 9% (at 1-year post-surgery, we were able to establish contact with 101 patients). The pre-op BMI was significantly higher in the BOAGB group compared to the other procedures. Additionally, a higher prevalence of diabetes was observed in the BOAGB group. The duration of surgery was significantly longer for the BOAGB procedure. No significant differences were found in surgical complications. Overall, all procedures resulted in significant excess weight loss (EWL) or change in BMI, improvement in comorbidities, and improved quality of life postoperatively.

CONCLUSIONS

The BOAGB procedure, like OAGB and SG, demonstrated favorable weight loss outcomes and weight maintenance 1 year postoperatively without significant differences between the procedures. The BOAGB procedure is relatively new, with good bariatric outcomes and a favorable safety profile. Long-term study is needed to evaluate these various bariatric procedures' efficacy further.

Laparoscopic sleeve gastrectomy vs one-anastomosis gastric bypass 5-year follow-up: a single-blinded randomized controlled trial

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is the most performed bariatric procedure worldwide, whereas one-anastomosis gastric bypass (OAGB) is the third most performed procedure. Both procedures have reported good weight loss (WL) and low complications. However, should both have differences in the durability of WL and malnutrition?

METHODS

A single-blinded, randomized controlled trial of 300 patients was conducted to compare the outcomes of LSG and OAGB over a 5-year follow-up. The primary endpoint was WL in percentages of total WL (%TWL) and excess WL (%EWL). The secondary endpoints were complications, gastroesophageal reflux disease (GERD), associated medical problems, bariatric analysis and reporting outcome system (BAROS) assessment, and weight recurrence (WR).

RESULTS

Overall, 201 patients (96 in the LSG group and 105 in the OAGB group) completed 5 years of follow-up. OAGB had significantly higher %TWL and %EWL than those of LSG throughout the follow-up. LSG had significantly higher WR and GERD. Both procedures had significant improvement in associated medical problems and BAROS scores compared with baseline, with no significant difference. WR was associated with higher relapse of associated medical conditions after initial remission and with lower BAROS scores regarding WL scores.

CONCLUSION

OAGB had significantly higher WL, less WR, and less GERD. However, it had a higher incidence of bile reflux. Both procedures had comparable complication rates, excellent remissions in associated medical problems, and improved quality of life. WR was associated with significantly more relapse of associated medical problems and significantly lower BAROS scores.

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.

Weight Reduction Percentile Charts: 2-Year Follow-up Results of OAGB and RYGB Post Bariatric Surgery

PURPOSE

Using a single percentile chart provides us with high standards for the evaluation and accurate investigation of sufficient weight loss after bariatric surgery, counseling, and treating patients in an evidence-based way. Creating percentile charts of weight loss for gastric bypass is the aim of this study.

MATERIALS AND METHODS

This retrospective study was based on data from patients who underwent RYGB or OAGB from February 2008 to February 2020. The lambda-mu-sigma (LMS) method was used to estimate the reduction in body mass index (BMI) and six other metrics measured throughout post-operative follow-up. Percentile charts for various metrics have been presented for the first 2 years' post-surgery. We applied a bootstrap sampling method to evaluate percentile validity.

RESULTS

We recruited 2579 and 1943 patients who underwent OAGB (75% female) and RYGB (84% female) and were between the ages of 18 and 70 years. The preoperative BMI of patients in the OAGB group was higher than in the RYGB group. Concerning RYGB weight reduction results, the maximum percentage of excess weight loss (%EWL) occurs 18 months after surgery and is steady at 24 months. Far above 50%, EWL is achieved after 6 months. OAGB weight loss follows the same trend as RYGB; at 6 months, the %EWL values are slightly higher than RYGB.

CONCLUSIONS

We present the first bariatric weight loss percentile chart for OAGB. It allows evaluation of sufficient and insufficient weight loss at any post-operative point in a visual aspect. Furthermore, it predicts prospective outcomes and guides patient monitoring.

Management of Early Postoperative Bleeding After OAGB: A Single-center Experience

INTRODUCTION

One anastomosis gastric bypass (OAGB) has gained popularity among bariatric surgeons due to the shorter operative time, fewer sites for anastomotic leaks and internal herniation, shorter learning curve, ease of reversibility and revision with equivalent results to Roux en Y gastric bypass in terms of weight loss and co-morbidity resolution. We present our experience in managing early postoperative bleeding after OAGB.

PATIENTS AND METHODS

Patients who underwent OAGB in Bariatric Surgery Unit, Ain Shams University Hospitals between January 2016 and January 2023 were followed up for 30 days for early postoperative complications. Patients were 210 females (70%) and 90 males, with a mean age of 41.3±7.1 years, and mean preoperative body mass index of 45.2±6.1 kg/m². The incidence of early postoperative bleeding, the sites of the bleeding and management strategy were reported.

RESULTS

Fourteen of 300 patients (4.67%) developed early postoperative bleeding after OAGB. Intraluminal bleeding occurred in 4 patients, 3 of which were controlled by endoscopy and one by laparoscopic suturing. Intra-abdominal bleeding occurred in 10 patients, 7 of which were successfully managed conservatively, and 3 required laparoscopic management. Two cases had both intra-abdominal bleeding and intraluminal bleeding in the distal stomach, confirmed by intraoperative endoscopy, and controlled by laparoscopic suturing.

CONCLUSION

Early postoperative bleeding after OAGB is a rare complication (4.67%). Conservative treatment is more successful in controlling intra-abdominal bleeding. In case of failed conservative treatment, laparoscopy is the method of choice. Most cases of intra-luminal bleeding need early endoscopic intervention.

Investigating the Prevalence of Copper and Zinc Abnormalities in Patients Pre and Post bariatric Surgery-an Australian Experience

INTRODUCTION

Bariatric surgery predisposes patients to nutritional deficiencies. There are limited studies on zinc and copper abnormalities in this cohort.

PURPOSE

The aim of this study was to identify the prevalence of these abnormalities in a cohort of Australian bariatric patients. Inflammatory markers, adherence to multivitamin supplementation (MVS) and the presence of gastrointestinal (GI) symptoms were also investigated.

MATERIAL AND METHODS

Data was collected on all patients who attended a single clinic in Sydney, Australia, from August 2020 to August 2021.

RESULTS

The study cohort consisted of 231 patients (76.2% female; mean pre-operative body mass index of 43.4 ± 7.1 kg/m2), most of whom underwent sleeve gastrectomy (78.8%). Data were collected preoperatively and then at ≤ 6 months, 1 and > 2 years postoperatively. Prior to surgery, low levels of zinc (2.1%) and copper (0.7%) were rare, but elevated copper levels were common (16.7%) and potentially related to an elevated C-reactive protein (CRP) (47.7%). Following surgery at > 2 years, the mean total weight loss (TWL) was 33.5 ± 12.4. CRP levels improved over time. Post operatively, low zinc (2.7-3.6%) and copper (1.5%) levels were rare. Patients with low levels in zinc and copper were a higher-risk group and generally exhibited GI symptoms, despite taking MVS.

CONCLUSION

In the initial post-operative stages and with good adherence to MVS containing copper and zinc, abnormalities may not be a concern. Patients with GI symptoms appear to be at higher risk of abnormalities; increasing awareness, thorough screening, and more comprehensive supplementation are recommended.

Comparison of single-anastomosis gastric bypass and sleeve gastrectomy on type 2 diabetes mellitus remission for obese patients: A meta-analysis of randomized controlled trials

Currently, the increasing numbers of one anastomosis gastric bypass (OAGB) brought this technique in the third position in order of frequency, behind sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). However, OAGB is still considered lack of evidence in reducing obesity- related comorbidities. Our study aimed to compare the efficacy for SG and OAGB improving type 2 diabetes mellitus (T2DM) remission and weight loss in obese patients. PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized controlled trials (RCTs) comparing OAGB and SG. Review Manager 5.4.1 was used to analyze the data, and the right effect model was chosen based on heterogeneity. Five randomized controlled trials were included in the study. The remission of T2DM in the OAGB group was more efficient at 1 year and 5 years. Meanwhile, the OAGB group has a greater improvement than the SG group in terms of hypertension (HTN) and fasting plasma glucose (FPG). Although the percentage of excess BMI loss (%EBMIL) between the OAGB and SG groups was not significant at 6 months, the OAGB group had a conspicuous %EBMIL at 1 year. And 5 years after surgery, a higher percentage of excess weight loss (%EWL) was found in the OAGB group. Besides, the OAGB group showed a lower body mass index (BMI) at 5 years than the SG group, but the BMI at 6 months and 1 year were not significant. Finally, at 6 months, the OAGB group exhibited a more remarkable percentage of total weight loss (%TWL) than the SG group. In general, OAGB exhibited a better therapeutic effect in T2DM, HTN, and weight loss than SG in the medium-term follow-up period. To assess the long-term efficacy, clinics should be encouraged to continue longer-term follow-up studies and possibly RCTs.

Short-term outcomes of double omentopexy in one anastomosis gastric bypass surgery: A controlled clinical trial

Purpose

This study aims to assess the efficacy of implementing a novel technique of reinforcement of gastric pouch and remnant stomach staple line with Double Omentopexy (DO) in patients undergoing One-Anastomosis Gastric Bypass (OAGB) surgery and evaluate its impact in reducing the early postoperative complications.

Materials and Methods

The 123 patients were allocated into two groups: 61 in the standard OAGB group and 62 in OAGB with DO group. The primary outcomes are postoperative complications (including early postoperative bleeding, leakage, gastric twist, reflux, etc.) and hospital stay. The secondary outcome is excess body weight loss. Follow-up visits were planned after discharge: at two weeks, two months, and three months postoperatively.

Results

Postoperative complications were significantly lower, 3 (4.84%) in OAGB with DO compared with 10 (16.39%) in standard OAGB (P =0.037). There was no statistically significant difference in the incidence of early postoperative bleeding, deep vein thrombosis, biliary reflux, and gall bladder stone (P >.05). No patient had leakage in either group. The mean operative time was significantly longer (68.66 ± 6.68 min) in OAGB with the DO group when compared with the standard OAGB group (62.16 ± 7.54 min) (P <.001).

Conclusion

Applying the DO technique may be a good measure to be added during OAGB to decrease the incidence of potential postoperative complications, especially the rate and severity of bleeding.

One Anastomosis Gastric Bypass for Revisional Bariatric Surgery: Assessment of Short-Term Safety

PURPOSE

With the continued increase in bariatric procedures being performed in the USA, a growing percentage are revisions for weight regain after sleeve gastrectomy (SG) and gastric banding (LAGB). Standard practice in the USA involves conversion to Roux-en-Y gastric bypass (RYGB). Internationally, one anastomosis gastric bypass (OAGB) has become a popular and effective alternative. Without the jejuno-jejunal anastomosis, OAGB has reduced potential related long-term complications. The purpose of this study is to compare the short-term safety of revision to OAGB versus RYGB.

MATERIALS AND METHODS

Patients who underwent conversion to OAGB from LAGB or SG for weight regain from January 2019 to October 2021 were compared to BMI, sex, and age-matched patients who underwent conversion to RYGB.

RESULTS

In our study, 82 patients were included, 41 in each cohort (41 OAGB vs. 41 RYGB). The majority in both groups underwent conversion from SG (71% vs. 78%). Operative time, estimated blood loss, and length of stay were comparable. There was no difference in 30-day complications (9.8% vs. 12.2%, p = .99) or reoperation (4.9% vs. 4.9%, p = .99). Mean weight loss at 1 month was also comparable (7.91 lbs vs 6.36 lbs).

CONCLUSIONS

Patients undergoing conversion to OAGB for weight regain had similar operative times, post-operative complication rates, and 1-month weight loss compared to those who underwent RYGB. While more research is needed, this early data suggests that OAGB and RYGB provide comparable outcomes when used as conversion procedures for to failed weight loss. Therefore, OAGB may present a safe alternative to RYGB.

Very Low-Calorie Ketogenic Diet (VLCKD) as Pre-Operative First-Line Dietary Therapy in Patients with Obesity Who Are Candidates for Bariatric Surgery

Bariatric surgery is currently the most effective method for achieving long-term weight loss and reducing the risk of comorbidities and mortality in individuals with severe obesity. The pre-operative diet is an important factor in determining patients' suitability for surgery, as well as their post-operative outcomes and success in achieving weight loss. Therefore, the nutritional management of bariatric patients requires specialized expertise. Very low-calorie diets and intragastric balloon placement have already been studied and shown to be effective in promoting pre-operative weight loss. In addition, the very low-calorie ketogenic diet has a well-established role in the treatment of obesity and type 2 diabetes mellitus, but its potential role as a pre-operative dietary treatment prior to bariatric surgery has received less attention. Thus, this article will provide a brief overview of the current evidence on the very low-calorie ketogenic diet as a pre-operative dietary treatment in patients with obesity who are candidates for bariatric surgery.

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.

Standardization of the One-anastomosis Gastric Bypass Procedure for Morbid Obesity: Technical Aspects and Early Outcomes

BACKGROUND

One-anastomosis gastric bypass (OAGB) has become an accepted metabolic/bariatric surgery procedure. This study aimed to describe our center's standardized OAGB operative technique and report early (≤30 d) safety outcomes in patients with severe obesity.

METHODS

The medical records of patients who had undergone either primary (n=681, 88.0%) or revisional OAGB (n=93, 12.0%) were retrospectively evaluated. Patient demographics, operative time, length of hospital stay, readmissions, reoperations, and ≤30-day morbidity and mortality rates were analyzed.

RESULTS

A total of 774 consecutive patients with severe obesity (647 female, 83.6%) underwent OAGB between January 2016 and December 2021. Their mean age was 36.2±10.8 years (range: 18 to 70 y) and mean body mass index was 42.7±4.2 kg/m 2 (range: 17.2 to 61 kg/m 2 ). Mean operating time was 52.6±19.9 minutes (range: 25 to 295 min) and length of hospital stay was 1.6±0.9 days (range: 1 to 9 d). Early postoperative complications occurred in 16 cases (2.1%), including 2 leaks with an intra-abdominal abscess (0.3%), bleeding (n=3, 0.4%), acute kidney failure (n=1, 0.15%), urinary tract infection (n=2, 0.3%), and intensive care unit stay (n=4, 0.5%). Seventy patients (9.1%) were readmitted, and re-laparoscopy was performed in 1 patient (0.1%). There was no mortality.

CONCLUSIONS

In the very early term, OAGB was a safe primary and revisional metabolic/bariatric surgery operation. Consistent performance of a standardized OAGB procedure contributed to low rates of morbidity and mortality in the hands of metabolic/bariatric surgeons with good laparoscopic skills at a high-volume center.

Metabolic and bariatric surgery in China: A summary of the Greater China Metabolic and Bariatric Surgery Database and comparison with other international registry databases

AIMS

To summarize the Greater China Metabolic and Bariatric Surgery Database (GC-MBD) and to compare patient characteristics and different procedures performed with data from published reports from other international bariatric surgery registries.

MATERIALS AND METHODS

Data were extracted from the GC-MBD registry in 2021. Baseline demographic characteristics, obesity-related comorbidities and operational information were analysed. Descriptive comparisons of these data were made with the published reports from four other international/national databases, including the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) registry, the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database of the United States, the National Bariatric Surgical Registry (NBSR) of the United Kingdom, and the Scandinavian Obesity Surgery Registry (SOReg).

RESULTS

Fifty-three centres in China registered 6807 cases in the GC-MBD. Compared with published data from the IFSO registry, MBSAQIP, NBSR and SOReg, patients in China undergoing surgery were younger and had a lower body mass index. The incidence of other obesity-related comorbidities, except for gastroesophageal reflux disease, was also higher than in Western countries. Furthermore, more patients underwent sleeve gastrectomy, less revisional bariatric surgery was reported in China, and jejunojejunal bypass with sleeve gastrectomy, uncommon in other countries, was China's second-leading bariatric procedure.

CONCLUSIONS

By establishing comprehensive national registries such as the GC-MBD, real-world information can be gathered on clinical practice and patient outcomes. Insights into variations in clinical practice can be identified by comparing reports from different countries, which can help in making and evaluating healthcare policies on the best clinical practices at a national level.

Investigating the prevalence of nutritional abnormalities in patients prior to and following bariatric surgery

AIMS

Bariatric surgery remains an effective treatment for the condition of obesity. However it predisposes patients to nutritional deficiencies and related complications. The aim of this study was to identify nutritional abnormalities, weight loss, adherence to supplements, and presence of gastrointestinal symptoms in a cohort of bariatric surgical patients.

METHODS

An analysis of the electronic medical records of patients attending a multidisciplinary private clinic in Sydney, Australia from August 2020 to August 2021 was conducted. Data on anthropometric measures, nutritional indices, adherence to supplements and gastrointestinal symptoms preoperatively and then at ≤6 months, 1 and 2 years or more postoperatively were collected.

RESULTS

A total of 231 patients were included in the study. The majority of patients were female (76.2%), with a sleeve gastrectomy (78.8%). Average preoperative BMI was 43.4 ± 7.1 kg/m² . Weight loss ≥2 years postsurgery was 33.5 ± 12.4 kg. The most common abnormalities preoperatively were: C-reactive protein (47.7%), vitamin D (39%), B₁₂ (31%), parathyroid hormone (27.6%) and ferritin (12.7%). Vitamin B₁₂ (23.2%), parathyroid hormone (23%), vitamin D (17.7%) and ferritin (15.9%) remained common abnormalities postoperatively. Adherence to multivitamins was 90% in the first year following surgery, declining to 77% at ≥2 years. Gastrointestinal symptoms were predominantly present in the initial stages following surgery, manifesting thiamin deficiency in 6.5% of patients.

CONCLUSIONS

Despite achieving durable weight loss, nutritional and related abnormalities remain an ongoing challenge for bariatric surgery. Adherence to nutrient supplements, gastrointestinal symptoms and related complications are important considerations in addressing the problem.

Efficacy and safety of one anastomosis gastric bypass versus Roux-en-Y gastric bypass for type 2 diabetes remission (ORDER): protocol of a multicentre, randomised controlled, open-label, superiority trial

INTRODUCTION

Previous studies have demonstrated that one anastomosis gastric bypass (OAGB) is not inferior to Roux-en-Y gastric bypass (RYGB) in treating obesity. However, high level evidence comparing the efficacy and safety of both procedures in type 2 diabetes (T2D) treatment is still lacking, which is another main aim of bariatric surgery. The presented trial has been designed to aim at investigating the superiority of OAGB over the reference procedure RYGB in treating T2D as primary endpoint. And diabetes-related microvascular and macrovascular complications, cardiovascular comorbidities, weight loss, postoperative nutritional status, quality of life and overall complications will be followed up for 5 years as secondary endpoints.

METHODS AND ANALYSIS

This prospective, multicentre, randomised superiority open-label trial will be conducted in patients of Asian descent. A total of 248 patients (BMI≥27.5 kg/m²) who are diagnosed with T2D will be randomly assigned (1:1) to OAGB or RYGB with blocks of four. The primary endpoint is the complete diabetes remission rate defined as HbA1c≤6.0% and fasting plasma glucose≤5.6 mmol/L without any antidiabetic medications at 1 year after surgery. All secondary endpoints will be measured at different follow-up visit points, which will start at least 3 months after enrolment, with a continuous annual follow-up for five postoperative years in order to provide solid evidence on the efficacy and safety of OAGB in patients with T2D.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee of leading centre (Beijing Friendship Hospital, Capital Medical University, no. 2021-P2-037-03). The results generated from this work will be disseminated to academic audiences and the public via publications in international peer-reviewed journals and conferences. The data presented will be imported into a national data registry. Findings are expected to be available in 2025, which will facilitate clinical decision-making in the field.

TRIAL REGISTRATION NUMBER

NCT05015283.

The United States Experience with One Anastomosis Gastric Bypass at MBSAQIP-Accredited Centers

PURPOSE

One anastomosis gastric bypass (OAGB) has emerged as a potentially safe and effective weight-loss procedure. Worldwide, OAGB is the third most commonly performed primary bariatric procedure, comprising 4% of the annual volume. In the USA, OAGB has yet to be endorsed as a primary bariatric procedure and can only be performed under research protocols or as a revision procedure.

MATERIALS AND METHODS

We performed an observational cohort study to describe the preoperative, intraoperative, and postoperative characteristics of adult patients who underwent primary or revision OAGB from 2015 to 2019 at MBSAQIP centers. Exclusion criteria included emergent surgery, incomplete 30-day follow-up, and non-laparoscopic- or robotic approach.

RESULTS

During the study period, 803,906 bariatric procedures were performed and 645 (0.08%) were OAGB. Among these, 436 (67.6%) were primary and 209 (32.4%) were revision OAGB. The mean operation time was 89 min (SD, 59) and 8% were performed using a robotic approach. The overall complication rate was 7.4% and there was one death (0.2%). The post-operative complication rates were generally higher than the early complication rate (3.4%) reported in the YOMEGA trial, an RCT from France. Revision OAGB had a longer mean operation time of 141 min (SD, 85, p < 0.001).

CONCLUSION

Primary OAGB was a rarely performed bariatric procedure at MBSAQIP-accredited centers comprising only 0.05% compared to 4% worldwide. Future studies should compare safety of OAGB to that of established bariatric procedures like Roux-en-Y gastric bypass and sleeve gastrectomy.

30-day morbidity and mortality of sleeve gastrectomy, Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-matched analysis of the GENEVA data

BACKGROUND

There is a paucity of data comparing 30-day morbidity and mortality of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB). This study aimed to compare the 30-day safety of SG, RYGB, and OAGB in propensity score-matched cohorts.

MATERIALS AND METHODS

This analysis utilised data collected from the GENEVA study which was a multicentre observational cohort study of bariatric and metabolic surgery (BMS) in 185 centres across 42 countries between 01/05/2022 and 31/10/2020 during the Coronavirus Disease-2019 (COVID-19) pandemic. 30-day complications were categorised according to the Clavien-Dindo classification. Patients receiving SG, RYGB, or OAGB were propensity-matched according to baseline characteristics and 30-day complications were compared between groups.

RESULTS

In total, 6770 patients (SG 3983; OAGB 702; RYGB 2085) were included in this analysis. Prior to matching, RYGB was associated with highest 30-day complication rate (SG 5.8%; OAGB 7.5%; RYGB 8.0% (p = 0.006)). On multivariate regression modelling, Insulin-dependent type 2 diabetes mellitus and hypercholesterolaemia were associated with increased 30-day complications. Being a non-smoker was associated with reduced complication rates. When compared to SG as a reference category, RYGB, but not OAGB, was associated with an increased rate of 30-day complications. A total of 702 pairs of SG and OAGB were propensity score-matched. The complication rate in the SG group was 7.3% (n = 51) as compared to 7.5% (n = 53) in the OAGB group (p = 0.68). Similarly, 2085 pairs of SG and RYGB were propensity score-matched. The complication rate in the SG group was 6.1% (n = 127) as compared to 7.9% (n = 166) in the RYGB group (p = 0.09). And, 702 pairs of OAGB and RYGB were matched. The complication rate in both groups was the same at 7.5 % (n = 53; p = 0.07).

CONCLUSIONS

This global study found no significant difference in the 30-day morbidity and mortality of SG, RYGB, and OAGB in propensity score-matched cohorts.

Esophageal and gastric malignancies after bariatric surgery: a retrospective global study

BACKGROUND

Bariatric surgery can influence the presentation, diagnosis, and management of gastrointestinal cancers. Esophagogastric (EG) malignancies in patients who have had a prior bariatric procedure have not been fully characterized.

OBJECTIVE

To characterize EG malignancies after bariatric procedures.

SETTING

University Hospital, United Kingdom.

METHODS

We performed a retrospective, multicenter observational study of patients with EG malignancies after bariatric surgery to characterize this condition.

RESULTS

This study includes 170 patients from 75 centers in 25 countries who underwent bariatric procedures between 1985 and 2020. At the time of the bariatric procedure, the mean age was 50.2 ± 10 years, and the mean weight 128.8 ± 28.9 kg. Women composed 57.3% (n = 98) of the population. Most (n = 64) patients underwent a Roux-en-Y gastric bypass (RYGB) followed by adjustable gastric band (AGB; n = 46) and sleeve gastrectomy (SG; n = 43). Time to cancer diagnosis after bariatric surgery was 9.5 ± 7.4 years, and mean weight at diagnosis was 87.4 ± 21.9 kg. The time lag was 5.9 ± 4.1 years after SG compared to 9.4 ± 7.1 years after RYGB and 10.5 ± 5.7 years after AGB. One third of patients presented with metastatic disease. The majority of tumors were adenocarcinoma (82.9%). Approximately 1 in 5 patients underwent palliative treatment from the outset. Time from diagnosis to mortality was under 1 year for most patients who died over the intervening period.

CONCLUSION

The Oesophago-Gastric Malignancies After Obesity/Bariatric Surgery study presents the largest series to date of patients developing EG malignancies after bariatric surgery and attempts to characterize this condition.

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.

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.

Surgical Treatment of Obesity. Special Mention to Roux-en-Y Gastric Bypass and Vertical Gastrectomy

INTRODUCTION

The prevalence of obesity has increased exponentially in recent decades, being one of the diseases that most affects global health. It is a chronic disease associated with multiple comorbidities, which lead to a decrease in life expectancy and quality of life. It requires a multidisciplinary approach by a specialized medical team. Obesity can be treated with conservative or with surgical treatments that will depend on the characteristics of the patient.

OBJECTIVE/METHODOLOGY

The referenced surgery can be performed using different surgical techniques that are analyzed in the present work through an exhaustive narrative bibliographic review in the PubMed and Cochrane databases, as well as in UpToDate.

RESULTS

Currently, those most used are restrictive techniques, specifically vertical gastrectomy and mixed techniques, with gastric bypass being the "gold standard".

CONCLUSIONS

In order to choose one technique or another, the characteristics of each patient and the experience of the surgical team must be taken into account.

Comparison of Short-term Safety of One Anastomosis Gastric Bypass to Roux-en-Y Gastric Bypass and Sleeve Gastrectomy in the United States: 341 cases from MBSAQIP-accredited Centers

BACKGROUND

One anastomosis gastric bypass (OAGB) is the third most common (4%) primary bariatric procedure worldwide but is seldom performed in the United States and is currently under consideration for endorsement by the American Society for Metabolic and Bariatric Surgery. Evidence from the United States on safety of OAGB compared to Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) is limited.

OBJECTIVE

To compare the short-term safety outcomes of the three primary bariatric procedures.

SETTING

Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP)-accredited hospitals in the United States and Canada.

METHODS

Using the 2015-2019 MBSAQIP database, we compared the safety outcomes of adult patients who underwent primary laparoscopic OAGB, RYGB, and SG. Exclusion criteria included age over 80 years, emergency operation, conversion, and incomplete follow-up. The primary outcome was 30-day overall complication. Secondary outcomes were 30-day surgical and medical complications and hospitalization length.

RESULTS

A total of 341 patients underwent primary OAGB. Using propensity scores, we matched the OAGB cohort 1:1 with two cohorts of similar baseline characteristics who underwent RYGB and SG, respectively. The OAGB cohort had a lower overall complication rate than the RYGB cohort (6.7% versus12.3%, P = .02) and a similar rate to the SG cohort (5.0%, P = .43). The OAGB cohort had a similar rate of surgical complication to the RYGB cohort (5.0% versus 8.5%, P = .1) and a higher rate than the SG group (1.2%, P = .009). The OAGB cohort had a shorter median hospitalization than the RYGB cohort (1 d [interquartile range (IQR) 1-2 d] versus 2 d [IQR 1-2 d], P < .001) and a similar hospitalization length to the SG cohort ([1-2 d], P = .46).

CONCLUSION

Using the largest and the most current U.S. data, this study demonstrated that the short-term safety profile of primary OAGB is acceptable, but future studies should determine the long-term safety.

GORD and Barrett's oesophagus after bariatric procedures: multicentre prospective study

INTRODUCTION

Gastro-oesophageal reflux disease (GORD) after bariatric surgery is a debated topic. This study investigated the prevalence of GORD and associated oesophageal complications following bariatric procedures-namely, adjustable gastric banding (AGB), sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one-anastomosis gastric bypass (OAGB).

METHODS

This was a prospective multicentre study designed to evaluate the long-term effects of bariatric surgery on GORD. Patients were studied at baseline, at >10 years following AGB, SG, and RYGB, and at >3 years following OAGB (due to the more recent recognition of OAGB as a standard bariatric procedure). Patients were assessed by endoscopy and GORD symptom evaluation.

RESULTS

A total of 241 patients were enrolled. A minimum follow-up of 10 years was completed by 193 patients following AGB (57 patients), SG (95 patients), and RYGB (41 patients), and of >3 years by 48 subjects following OAGB. GORD symptoms increased following AGB and SG (from 14 to 31.6 per cent and from 26.3 to 58.9 per cent, respectively; P < 0.0001), improved following RYGB (from 36.6 to 14.6 per cent; P < 0.0001), and were unchanged following OAGB. The overall prevalence of erosive oesophagitis was greater in the SG group (74.7 per cent) than in the AGB (42.1 per cent), RYGB (22 per cent), and OAGB (22.9 per cent) groups (P < 0.0001). Barrett's oesophagus was found only in patients who had SG (16.8 per cent). Biliary-like gastric stagnation was found in a greater proportion of SG and OAGB patients (79.7 and 69.4 per cent, respectively) than in other treatment groups (P < 0.0001). The prevalence of biliary-type reflux into the oesophagus was higher in patients who underwent SG (74.7 per cent), compared with other treatment groups.

CONCLUSION

Bariatric surgery leads to gastro-oesophageal complications of variable severity, particularly SG, which can result in a large proportion of patients developing Barrett's oesophagus.

Network Meta-Analysis of Metabolic Surgery Procedures for the Treatment of Obesity and Diabetes

Background

Metabolic surgery is part of a well-established treatment intensification strategy for obesity and its related comorbidities including type 2 diabetes (T2DM). Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) and one-anastomosis gastric bypass (OAGB) are the most commonly performed metabolic surgeries worldwide, but comparative efficacy is uncertain. This study employed network meta-analysis to compare weight loss, T2DM remission and perioperative complications in adults between RYGB, SG and OAGB.

Methods

MEDLINE, EMBASE, trial registries were searched for randomised trials comparing RYGB, SG and OAGB. Study outcomes were excess weight loss (at 1, 2 and 3–5 years), trial-defined T2DM remission at any time point and perioperative complications.

Results

Twenty randomised controlled trials were included involving 1803 patients investigating the three metabolic surgical interventions. RYGB was the index for comparison. The excess weight loss (EWL) demonstrated minor differences at 1 and 2 years, but no differences between interventions at 3–5 years. T2DM remission was more likely to occur with either RYGB or OAGB when compared to SG. Perioperative complications were higher with RYGB when compared to either SG or OAGB. Two-way analysis of EWL and T2DM remission against the risk of perioperative complications demonstrated OAGB was the most positive on this assessment at all time points.

Conclusion

OAGB offers comparable metabolic control through weight loss and T2DM remission to RYGB and SG whilst minimising perioperative complications.

Registration number: CRD42020199779 (https:// www.crd.york.ac.uk/PROSPERO)

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.

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.

Bile Reflux is a Common Finding in the Gastric Pouch After One Anastomosis Gastric Bypass

INTRODUCTION

Data on postoperative bile reflux after one anastomosis gastric bypass (OAGB) is lacking. Bile reflux scintigraphy (BRS) has been shown to be a reliable non-invasive tool to assess bile reflux after OAGB. We set out to study bile reflux after OAGB with BRS and endoscopy in a prospective series (RYSA Trial).

METHODS

Forty patients (29 women) underwent OAGB between November 2016 and December 2018. Symptoms were reported and upper gastrointestinal endoscopy (UGE) was done preoperatively. Six months after OAGB, bile reflux was assessed in UGE findings and as tracer activity found in gastric tube and esophagus in BRS (follow-up rate 95%).

RESULTS

Twenty-six patients (68.4%) had no bile reflux in BRS. Twelve patients (31.6%) had bile reflux in the gastric pouch in BRS and one of them (2.6%) had bile reflux also in the esophagus 6 months postoperatively. Mean bile reflux activity in the gastric pouch was 5.2% (1-21%) of total activity. De novo findings suggestive of bile reflux (esophagitis, stomal ulcer, foveolar inflammation of gastric pouch) were found for 15 patients (39.5%) in postoperative UGE. BRS and UGE findings were significantly associated (P = 0.022). Eight patients experienced de novo reflux symptoms at 6 months, that were significantly associated with BRS and de novo UGE findings postoperatively (P = 0.033 and 0.0005, respectively).

CONCLUSION

Postoperative bile reflux in the gastric pouch after OAGB is a common finding in scintigraphy and endoscopy. The long-term effects of bile exposure will be analyzed in future reports after a longer follow-up.

TRIAL REGISTRATION

Clinical Trials Identifier NCT02882685.

Changes in Anthropometric Measures, Nutritional Indices and Gastrointestinal Symptoms Following One Anastomosis Gastric Bypass (OAGB) Compared with Roux-en-y Gastric Bypass (RYGB)

Purpose

Bariatric surgery is an effective treatment for obesity with new procedures emerging. However, despite comparable weight loss and improvements in metabolic outcomes, research on nutritional and gastrointestinal symptoms remains limited. Here we compare clinical data on weight, nutritional disorders and gastrointestinal symptoms of patients before and following one anastomosis gastric bypass (OAGB) and Roux-en-Y gastric Bypass (RYGB).

Materials and Methods

In this retrospective study, data on anthropometry, nutritional indices, dietary intake and gastrointestinal symptoms were retrieved in cohorts of patients up to 2 years following OAGB and RYGB.

Results

Seventy-three patients had either a RYGB (28) or an OAGB (45), with 71% seeking these as a revisional procedure. Significant and higher weight loss was observed in the OAGB cohort at 1 year (%TWL 33.0 ± 8.5 vs. 26.6 ± 12.4), albeit comparable at 2 years postoperatively (%TWL 29.0 ± 11.1 vs. 34.1 ± 11.2). Disorders such as vitamin D, active B12, folate, homocystein (Hcy) and hyperparathyroidism were present following both surgeries. Levels of vitamin D, ferritin and total protein significantly worsened over time. Gastrointestinal symptoms of diarrhoea, steatorrhoea and reflux were higher in the OAGB cohort while the RYGB cohort reported more dumping syndrome (DS).

Conclusion

Significant and similar weight loss results are seen following both OAGB and RYGB. Nutritional disorders were common in both cohorts and increased over time. However, the OAGB patients reported more gastrointestinal side effects, which may contribute to poor quality of life and nutritional consequences. Prospective and longer-term studies investigating the nutritional and gastrointestinal health of patients undergoing OAGB is recommended.

Weight Regain After Bariatric Surgery-A Multicentre Study of 9617 Patients from Indian Bariatric Surgery Outcome Reporting Group

BACKGROUND

There is little robust data on weight regain (WR) after bariatric surgery making it difficult to counsel patients regarding long-term outcomes of different bariatric procedures. The purpose of this study was to see WR in medium and long term after SG, RYGB, and OAGB in Indian population.

METHODS

In a multicentre study, data on preoperative and postoperative weights over 5 years were collected. Multiple definitions were applied to find the proportion of patients with significant WR increase of 25% of lost weight from nadir (definition 1), weight gain of > 10 kg from nadir (definition 2), and BMI gain of > 5 kg/m² from nadir (definition 3). The proportion of those with significant WR was compared across sub-groups.

RESULTS

A total of 9617 patients were included. Median WR at 5 years was 14.1% of lost weight, 1.92 kg/m², and 5 kg. Significant WR using definition 1 was 35.1%, 14.6%, and 3% after sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and mini-one anastomosis gastric bypass (OAGB) respectively. Severe albumin deficiency was highest in OAGB (5.9%) patients followed by SG (2.9%) and RYGB (2.2%) at 5 years(p = 0.023). Haemoglobin levels < 10 g/dL were seen in 8.2%, 9.0%, and 13.9% of SG, RYGB, and OAGB patients respectively (p = 0.041).

CONCLUSIONS

In the first comparative study of WR, OAGB had lesser WR in comparison to SG and RYGB but had the most impact on Hb and albumin levels in the long term. Definition selection for reporting WR has a significant impact on the results. There is a need for standardising the reporting of WR in bariatric literature.

Efficiency and risks of one-anastomosis gastric bypass

The single-anastomosis gastric bypass has been proposed as a simpler and efficient weight loss reducing surgery. Postoperative outcomes are comparable to those of contemporary popular procedures. There are, however, controversies regarding the efficiency and risks of one-anastomosis gastric bypass (OAGB). The purpose of this review is to define the role of OAGB in metabolic surgery via its operative outcomes. A review of English language literature was performed using the PubMed database, basing the search on the following keywords: “one-anastomosis gastric bypass” AND “outcomes”. A total of 238 articles were considered for review. Following thorough screening and selection criteria, 7 articles were considered sufficient for assessment. The nature of the available evidence of this technique poses a challenge to OAGB in its establishment as a standard of care procedure. The anatomical configuration following surgery, as well as the metabolic implications of its hypo-absorptive nature, raises controversial and ongoing concerns that are yet to be addressed. Hence, prospective studies with long-term follow-up (>5 years) can bypass these concerns and allow the progression of the clinical practice of OAGB.

Weight Loss and Vomiting 1 Year After Banded Versus Non-banded One Anastomosis Gastric Bypass: a Prospective Randomized Trial

BACKGROUND

The weight loss outcomes after banded one-anastomosis gastric bypass (OAGB) remain to be determined.

OBJECTIVE

To compare weight loss and vomiting 1 year after banded versus non-banded OAGB.

METHODS

This is a prospective, open-label, randomized study, which evaluated 33 individuals with morbid obesity, which underwent banded (16 individuals) and non-banded OAGB (17 individuals) and were followed up for 12 months. Weight loss (percentages of total weight loss-%TWL-and excess weight loss-%EWL) and occurrence of vomiting were assessed and compared before surgery and after 6 and 12 months.

RESULTS

At baseline, there were no differences between groups in regard to age, gender, and body mass index (BMI). At 6 and 12 months post-op, and the overall mean %TWL regardless of band use was 22.4 ± 7% and 29 ± 6.9%, respectively, and the overall average %EWL regardless of band use was 66.8 ± 22.9% and 86.3 ± 24%, respectively. %TWL did not differ between the banded and non-banded groups at 6 (21.8 ± 6.8% vs. 23.1 ± 7.4%; p = 0.7) and 12 months post-op (27.5 ± 6.6% vs. 30.4 ± 7.1%; p = 0.3), as well as %EWL at 6 (67 ± 22.9% vs. 67.6 ± 23.6%; p = 0.6) and 12 months post-op (83.5 ± 24.4% vs. 89 ± 24.1%; p = 0.4). The occurrence of vomiting did not significantly differ between banded and non-banded OAGB at 6 (12.5% vs. 11.8%; p = 0.9) and 12 months post-op (12.5% vs. 5.9%; p = 0.5).

CONCLUSION

OAGB led to an overall satisfactory weight loss after 1 year, regardless of band use. Banded OAGB did not lead to neither significantly higher weight loss nor more vomiting than non-banded OAGB 1 year after surgery.

Short- and Mid-term Outcomes of 527 One Anastomosis Gastric Bypass/Mini-Gastric Bypass (OAGB/MGB) Operations: Retrospective Study

BACKGROUND

One anastomosis gastric bypass/mini-gastric bypass (OAGB/MGB) is considered an alternative option in metabolic and bariatric surgery. The aim of this study was to evaluate the safety, efficacy and postoperative challenges of OAGB/MGB as a new procedure.

METHODS

We performed 519 primary MGBs and 8 additional second-stage MGBs during 2014-2018. The data were collected from patients' notes as well as the surgeons' prospective data sheets. Two senior surgeons performed the operations. The ultimate primary measures were assessment of the safety and management of the complications. The secondary outcomes were excess weight loss and resolution of the comorbidities.

RESULTS

The type 2 diabetes mellitus (T2DM) remission rate was 83% and 70% over 1 and 3 years, respectively (HBA1C < 6.5%). Weight loss was 28-152 kg (SD 23.11). Excess weight loss ranged from 41 to 125%. Hypertension resolution was 61%, 58% and 58% in the first, second and third years, respectively. Ninety-nine per cent of sleep apnoea patients improved symptomatically and went off the continuous positive airway pressure (CPAP) machine. Two (0.37%) patients developed diarrhoea, cured by shortening the afferent biliopancreatic limb (BPL). Eight (1.5%) stomal ulcers were reported. Two patients (0.37%) developed deranged liver function, revised by shortening the BPL in one patient and a reversal in the second patient. The mean follow-up was 2.5 years. Mortality was zero.

CONCLUSIONS

This is the largest UK OAGB/MGB study to date showing safety and acceptable results for metabolic syndrome and obesity problems. OAGB/MGB revisional options are rectifying the morbidity and no mortality.

Prospective randomized controlled trial comparing the efficacy and safety of Roux-en-Y gastric bypass and one-anastomosis gastric bypass (the RYSA trial): trial protocol and interim analysis

INTRODUCTION

There is a lack of prospective studies comparing Roux-en-Y gastric bypass (RYGB) and one-anastomosis gastric bypass (OAGB). Also, the effects of bariatric surgery and weight loss need a deeper understanding through metabolic studies. We describe the trial protocol and interim analysis of a prospective randomized controlled study comparing RYGB and OAGB: the RYSA trial.

MATERIALS AND METHODS

In total, 120 bariatric patients will be randomized between RYGB and OAGB in two academic centers. All patients will be followed up for 10 years with analysis and measurements of weight, comorbidities, blood tests, body composition and questionnaires. Extensive metabolic analyses (mixed meal tests, energy expenditure, biopsies of muscle and subcutaneous fat, urine, saliva and fecal samples) will be carried out in the Obesity Research Unit, University of Helsinki, for all patients treated at the Helsinki University Hospital (80 patients) at baseline, 6 months and 12 months. Bile reflux will be studied for the OAGB group at the Helsinki University Hospital at 6 months with gastroscopy and scintigraphy.

RESULTS

At an interim analysis at 3 months (half-way) through recruitment (30 RYGB and 30 OAGB patients) there have been no deaths and no intensive care unit admittances. One patient in both groups required additional gastroscopy, with anastomosis dilatation in the RYGB group but with no additional intervention in the OAGB group.

CONCLUSION

The trial can be safely carried out. Recruitment is estimated to be complete by the end of 2019.

TRIAL REGISTRATION

Clinical Trials Identifier NCT02882685. Registered on August 30th 2016.

Conversion from laparoscopic adjustable gastric banding (LAGB) and laparoscopic sleeve gastrectomy (LSG) to one anastomosis gastric bypass (OAGB): preliminary data from a multicenter retrospective study

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is the most commonly performed bariatric procedure, while laparoscopic adjustable gastric banding (LAGB) has been for a decade one of the most popular interventions for weight loss. After LSG and LAGB, some patients may require a second surgery due to weight regain or late complications. One anastomosis gastric bypass (OAGB) is a promising bariatric procedure, which provides effective long-term weight loss and has a favorable effect on type 2 diabetes.

OBJECTIVES

To retrospectively analyze data from 10 Italian centers on conversion from LAGB and LSG to OAGB.

SETTING

High-volume centers for bariatric surgery.

METHODS

Prospectively collected data from 10 high-volume centers were retrospectively reviewed. Body mass index (BMI), percentage of excess BMI loss, reasons for redo, remission from co-morbidities (hypertension, diabetes, gastroesophageal reflux, and dyslipidemia), and major complications were recorded.

RESULTS

Three hundred patients were included in the study; 196 patients underwent conversion from LAGB to OAGB and 104 were converted from LSG. BMI was 45.1 ± 7 kg/m² at the time of first intervention, 41.8 ± 6.3 kg/m² at redo time, and 30.5 ± 5.5 kg/m² at last follow-up appointment. Mean percentage of excess BMI loss was 13.2 ± 28.2 at conversion and 73.4 ± 27.5 after OAGB. Remission rates from hypertension, diabetes, gastroesophageal reflux, and dyslipidemia were 40%, 62.5%, 58.7% and 52%, respectively. Mean follow-up was 20.8 (range, 6-156) months and overall complications rate was 8.6%.

CONCLUSION

Our data show that OAGB is a safe and effective revisional procedure after failed restrictive bariatric surgery.