One Anastomosis/Mini-Gastric Bypass (OAGB/MGB) as Revisional Surgery Following Primary Restrictive Bariatric Procedures: a Systematic Review and Meta-Analysis

Decision-making Considerations in Revisional Bariatric Surgery

OBJECTIVE

With drastic variations in bariatric practices, consensus is lacking on an optimal approach for revisional bariatric surgeries.

MATERIALS AND METHODS

The authors reviewed and consolidated bariatric surgery literature to provide specific revision suggestions based on each index surgery, including adjustable gastric band (AGB), sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), biliopancreatic diversion with duodenal switch (BPD-DS), single anastomosis duodenal-ileal bypass with sleeve (SADI-S), one anastomosis gastric bypass (OAGB), and vertical banded gastroplasty (VBG).

RESULTS

AGB has the highest weight recurrence rate and can be converted to RYGB, SG, and BPD-DS. After index SG, common surgical options include a resleeve or RYGB. The RYGB roux limb can be distalized and pouch resized in context of reflux, and the entire anatomy can be revised into BPD-DS. Data analyzing revisional surgery after a single anastomosis duodenal-ileal bypass with sleeve was limited. In patients with one anastomosis gastric bypass and vertical banded gastroplasty anatomy, most revisions were the conversion to RYGB.

CONCLUSIONS

As revisional bariatric surgery becomes more common, the best approach depends on the patient's indication for surgery and preexisting anatomy.

Revision/Conversion Surgeries After One Anastomosis Gastric Bypass-An Experts' Modified Delphi Consensus

PURPOSE

There is a lack of evidence for treatment of some conditions including complication management, suboptimal initial weight loss, recurrent weight gain, or worsening of a significant obesity complication after one anastomosis gastric bypass (OAGB). This study was designed to respond to the existing lack of agreement and to provide a valuable resource for clinicians by employing an expert-modified Delphi consensus method.

METHODS

Forty-eight recognized bariatric surgeons from 28 countries participated in the modified Delphi consensus to vote on 64 statements in two rounds. An agreement/disagreement among ≥ 70.0% of the experts was regarded to indicate a consensus.

RESULTS

A consensus was achieved for 46 statements. For recurrent weight gain or worsening of a significant obesity complication after OAGB, more than 85% of experts reached a consensus that elongation of the biliopancreatic limb (BPL) is an acceptable option and the total bowel length measurement is mandatory during BPL elongation to preserve at least 300-400 cm of common channel limb length to avoid nutritional deficiencies. Also, more than 85% of experts reached a consensus on conversion to Roux-en-Y gastric bypass (RYGB) with or without pouch downsizing as an acceptable option for the treatment of persistent bile reflux after OAGB and recommend detecting and repairing any size of hiatal hernia during conversion to RYGB.

CONCLUSION

While the experts reached a consensus on several aspects regarding revision/conversion surgeries after OAGB, there are still lingering areas of disagreement. This highlights the importance of conducting further studies in the future to address these unresolved issues.

Proximal Jejuno-Ileal Bypass as Revision of Roux-en-Y Gastric Bypass

INTRODUCTION

Bariatric surgery is established as a possibility for the treatment of obesity, allowing weight reduction and remission of obesity comorbidities. Reported suboptimal clinical response rates are as high as 30-60% (insufficient weight loss or gain, defined as BMI greater than 35 kg/m2 or excess weight loss less than 50%). Proximal jejuno-ileal bypass (PJIBP) is a promising option when re-intervention is required.

OBJECTIVES

To describe the standardization of a proprietary technique of modified PJIBP as a management procedure in patients with post-gastric bypass recurrent weight gain or insufficient post-intervention weight loss.

METHODS

This study evaluated a case series of 10 Latin American patients requiring post-bariatric re-intervention, between February 2018 and 2023, in a single-metabolic surgery center in Cali-Colombia.

RESULTS

Median age was 45 years (26-70 RIC), 60% female, and 40% male. Mean BMI at conversion was 36.7 kg/m2 (6.4 SD). Median follow-up was 22 months (RIC 16-30). Mean percentage of excess weight lost was 78% (22.4 SD). One hundred percent achieved glycemia control, only one patient persisted with dyslipidemia, and no patient presented hypoalbuminemia. At the end of follow-up, 100% received vitamin supplementation.

CONCLUSION

PJIBP could be an effective procedure, associated with positive results in relation to weight loss and resolution of obesity comorbidities. Deficiencies of fat-soluble vitamins and protein malnutrition represent the main concern in the long term, so multidisciplinary management and continuous follow-up are required.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of revisional surgeries after OAGB versus RYGB: Results from the multicenter Polish Revision Obesity Surgery Study (PROSS)

<br><b>Introduction:</b> Roux-en-Y gastric bypass (RYGB) is a leading bariatric surgery globally. One-anastomosis gastric bypass (OAGB), a modification of RYGB, ranks as the third most common bariatric procedure in Poland. While clinical trials show that OAGB outcomes are comparable to those of RYGB regarding weight loss, remission of comorbidities, and hormonal impact, there is limited data on long-term outcomes and complications.</br><br><b>Aim:</b> The aim of the study was to compare the outcomes of revisional surgeries conducted after OAGB <i>versus</i> RYGB.</br> <br><b>Material and methods:</b> This retrospective study analyzed patients undergoing revisional bariatric surgeries from January 2010 to January 2020 across 12 Polish centers. The inclusion criteria were an age of at least 18 years and prior OAGB or RYGB surgery. Those with incomplete primary surgery data and follow-up post-revision were excluded. Data were collected regarding parameters for anthropometrics, comorbidities, and perioperative details. The patients were categorized based on their initial surgery: OAGB or RYGB. The primary endpoints were the reasons for and types of revisional surgery and weight changes; the secondary endpoints were postoperative complications and length of hospital stay (LOS).</br> <br><b>Results:</b> In total, 27 patients participated, with a mean age of 38.18 7 years. Differences between the OAGB (13 patients) and RYGB (14 patients) groups included median initial body weight (100 kg <i>vs.</i> 126 kg, p<0.016), number of postoperative complications (9 <i>vs.</i> 3, p = 0.021), and median LOS (3 <i>vs.</i> 4.5 days, p = 0.03). GERD was the primary reason for OAGB revisions (69.2%), whereas insufficient weight loss led to the most RYGB revisions (42.9%).</br><br><b>Conclusions:</b> The RYGB patients commonly needed revisions due to weight issues, whereas reoperations in the OAGB patients were conducted due to postoperative complications. The postoperative complications and LOS were similar between the groups.</br> <br><b>The importance of research for the development of the field:</b> The results may influence clinical surgeons' choice of surgical technique.</br>.

One Anastomosis Gastric Bypass as Revisional Surgery Following Sleeve Gastrectomy: A Systematic Review and Meta-Analysis

BACKGROUND

Although sleeve gastrectomy (SG) is the most performed metabolic and bariatric surgery (MBS) worldwide, some patients require conversional procedures due to weight recurrence or late complications. Recently, one-anastomosis gastric bypass (OAGB) gained popularity as a viable option to address those problems. The aim of this meta-analysis is to assess the safety and efficacy of conversional OAGB after primary SG in the management of patients with obesity.

METHODS

Cochrane, Embase, PubMed, Scopus, and Web of Science were searched for articles from their inception to February 2023 by two independent reviewers using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) system. The review was registered prospectively with PROSPERO (CRD42023403528).

RESULTS

From 1,117 studies screened, twenty studies met the eligibility criteria, with a total of 1,057 patients with obesity undergoing conversional OAGB after primary SG. The mean age ranged from 28.2 to 49.5 years, and 744 patients (75.2%) were women. At one year after revisional OAGB, the pooled mean percent excess weight loss (%EWL) was 65.2% (95%CI: 56.9, 73.4, I2 = 97%). The pooled mean %EWL after conversional OAGB was 71.1% (95%CI: 62.2, 80.0, I2 = 90%) at two years and 71.6% (95%CI: 61.0, 82.2, I2 = 50%) at five years. Additionally, resolution rates of diabetes and hypertension were 65.4% (95%CI: 0.522, 0.785, I2 = 65%) and 58.9% (95%CI: 0.415, 0.762, I2 = 89%), respectively.

CONCLUSIONS

Our meta-analysis demonstrated OAGB as an effective conversional procedure after primary SG in terms of weight loss and obesity-associated medical problems for selected patients. Despite the promising results, further randomized controlled studies with larger sample sizes and more extended follow-up periods are necessary to determine if the OAGB is the best conversional surgery after SG.

ReSleeve or revisional one anastomosis gastric bypass for failed primary sleeve gastrectomy with dilated gastric tube: a retrospective study

BACKGROUND

Revisional bariatric surgery (RBS) has been increasingly performed due to weight loss failure (WLF). Many revisional procedures have been proposed after primary laparoscopic sleeve gastrectomy (pLSG) failure, including ReSleeve gastrectomy (ReLSG), and laparoscopic one anastomosis gastric bypass (LOAGB). Choosing the RBS post-pLSG failure represents a challenge. WLF without gastric tube (GT) dilation is undoubtedly converted to a malabsorptive procedure, but the presence of GT dilation makes it more difficult to select a RBS. This study aimed to compare two relatively simple revisional procedures after pLSG failure with dilated GT to help decision making on which procedure better done to which patient.

METHODS

Data of 52 patients who completed one year follow-up (FU) after their RBS (ReLSG: 27 or LOAGB: 25) for their failed pLSG were collected, assessed, correlated to weight loss (WL) and compared.

RESULTS

Mean operative time was 97 ± 18.4 min. with revisional LOAGB (RLOAGB) and 62 ± 11 min. with ReLSG. Six patients (11.5%) had seven postoperative procedure-specific complications. Significant hemorrhage occurred in three patients. Two cases of leakage were encountered with each procedure. LOAGB Patients had lower mean final weight (76.2 ± 10.5 vs 85.3 ± 13), lower mean Final BMI (26.4 ± 2.5 vs 29.7 ± 2.9) and higher mean percentage of excess weight loss (EWL%) (83.6 ± 13.5% vs 60.29 ± 14.6%). All RLOAGB patients and 77.8% of ReLSG patients had EWL% > 50%. RLOAGB patients had higher EWL% compared to ReLSG (p < 0.001). Insufficient WL (IWL) patients had higher EWL% compared to weight regain (WR) patients (p = 0.034).

CONCLUSION

Both procedures (RLOAGB and ReLSG) were relatively safe and effective in terms of WL. RLOAGB led to higher WL compared to ReLSG in all types of patients despite higher Caloric intake. IWL patients had more WL compared to WR patients. WL was not related to GT dilation type. Large-scale longer-FU studies are still needed.

TRIAL REGISTRATION

PACTR202310644487566 (retrospectively registered).

[ICG angiography is a safety standard in bariatric surgery]

OBJECTIVE

To examine the specific characteristics of ICG-angiography during various bariatric interventions.

MATERIAL AND METHODS

The study included 329 patients, with 105 (32%) undergoing sleeve gastrectomy (LSG), 98 (30%) undergoing mini-gastricbypass (MGB), 126 (38%) undergoing Roux-en-Y gastric bypass (RGB). Intraoperative ICG angiography was perfomed on all patients at 'control points', the perfusion of the gastric stump was qualitatively and quantitatively assessed.

RESULTS

Intraoperative ICG angiography shows that during LSG the angioarchitectonics in the area of the His angle are crucial. The presence of the posterior gastric artery of the gastric main type is a prognostically unfavorable risk factor for the development of ischemic complications. Therefore, to expand the gastric stump it is necessary to suture a 40Fr nasogastric tube and perform peritonization of the staple line. Statistical difference in blood supply at three points were found between and within the two groups of patients (Gis angle area, gastric body, pyloric region) with a p-value <0.001. During MGB, one of the important stages is applying the first (transverse) stapler cassette between the branches of the right and left gastric arteries. This maintains blood supply in anastomosis area, preventing immediate complications such as GEA failure, as well as long-term complications like atrophic gastritis, peptic ulcers, and GEA stenosis.

CONCLUSION

ICG angiography is a useful method for intraoperative assessment of angioarchitecture and perfusion of the gastric stump during bariatric surgery. This helps prevent tissue ischemia and reduce the risk of early and late postoperative complications.

One anastomosis gastric bypass as a primary bariatric surgery: MBSAQIP database analysis of short-term safety and outcomes

BACKGROUND

One anastomosis gastric bypass (OAGB) is described as a simpler, potentially safe, and effective bariatric-metabolic procedure that has been recently endorsed by the American Society of Metabolic and Bariatric Surgery.

OBJECTIVES

First, we aim to compare the 30-day outcomes between OAGB and other bypass procedures: Roux-en-Y gastric bypass (RYGB) and single anastomosis duodenoileal bypass with sleeve gastrectomy (SADI-S). Second, identify the odds between postoperative complications and each surgical procedure.

METHODS

Patients who underwent primary OAGB, RYGB, and SADI-S were identified using the MBSAQIP database of 2020 and 2021. An analysis of patient demographics and 30-day outcomes were compared between these three bypass procedures. In addition, a multilogistic regression for overall complications, blood transfusions, unplanned ICU admissions, readmission, reoperation, and anastomotic leak stratified by surgical procedure was performed.

RESULTS

1607 primary OAGBs were reported between 2020 and 2021. In terms of patient demographics, patients who underwent RYGB and SADI-S showed a higher incidence of comorbidities. On the other hand, OAGB had shorter length of stay (1.39 ± 1.10 days vs 1.62 ± 1.42 days and 1.90 ± 2.04 days) and operative times (98.79 ± 52.76 min vs 125.91 ± 57.76 min and 139.85 ± 59.20 min) than RYGB and SADI-S. Similarly, OAGB showed lower rates of overall complications (1.9% vs 4.5% and 6.4%), blood transfusions (0.4% vs 1.1% and 1.8%), unplanned ICU admission (0.3% vs 0.8% and 1.4%), readmission (2.4% vs 4.9% and 5.0%), and reoperation (1.2% vs 1.9% and 3.1%). A multilogistic regression analysis was performed, RYGB and SADI-S demonstrated higher odds of 30-day complications.

CONCLUSION

The incidence of primary OAGB has increased since its approval by ASMBS, from 0.05% reported between 2015 and 2019 to 0.78% between 2020 and 2021. OAGB had better 30-day outcomes and shorter operative times than RYGB and SADI-S and therefore, could be considered a viable alternative.

Vitamin D status and supplementation before and after Bariatric Surgery: Recommendations based on a systematic review and meta-analysis

Bariatric surgery is associated with a postoperative reduction of 25(OH) vitamin D levels (25(OH)D) and with skeletal complications. Currently, guidelines for 25(OH)D assessment and vitamin D supplementation in bariatric patients, pre- and post-surgery, are still lacking. The aim of this work is to analyse systematically the published experience on 25(OH)D status and vitamin D supplementation, pre- and post-surgery, and to propose, on this basis, recommendations for management. Preoperatively, 18 studies including 2,869 patients were evaluated. Prevalence of vitamin D insufficiency as defined by 25(OH)D < 30 ng/mL (75 nmol/L) was 85%, whereas when defined by 25(OH)D < 20 ng/mL (50 nmol/L) was 57%. The median preoperative 25(OH)D level was 19.75 ng/mL. After surgery, 39 studies including 5,296 patients were analysed and among those undergoing either malabsorptive or restrictive procedures, a lower rate of vitamin D insufficiency and higher 25(OH)D levels postoperatively were observed in patients treated with high-dose oral vitamin D supplementation, defined as ≥ 2,000 IU/daily (mostly D3-formulation), compared with low-doses (< 2,000 IU/daily). Our recommendations based on this systematic review and meta-analysis should help clinical practice in the assessment and management of vitamin D status before and after bariatric surgery. Assessment of vitamin D should be performed pre- and postoperatively in all patients undergoing bariatric surgery. Regardless of the type of procedure, high-dose supplementation is recommended in patients after bariatric surgery.

One-anastomosis gastric bypass (OAGB) versus Roux-en-Y gastric bypass (RYGB) as revisional procedures after failed laparoscopic sleeve gastrectomy (LSG): systematic review and meta-analysis of comparative studies

INTRODUCTION

The aim of this study was to compare weight loss and gastroesophageal reflux disease (GERD) remission after one-anastomosis gastric bypass (OAGB) versus Roux-en-Y gastric bypass (RYGB) as revisional procedures after laparoscopic sleeve gastrectomy (LSG).

METHODS

In PubMed, Embase, and Cochrane Library, a search was performed using the terms "Roux-en-Y gastric bypass versus one anastomosis gastric bypass," "revisional surgery," and "sleeve gastrectomy." Only original articles in English language comparing OAGB and RYGB were included. No temporal interval was set. The primary outcome measure was weight loss (%TWL). The secondary endpoints were leak, bleeding, marginal ulcer, and GERD. PRISMA flowchart was used. Differences in continuous and dichotomous outcome variables were expressed as mean difference (MD) and risk difference (RD) with 95% CI, respectively. Heterogeneity was assessed by using I2 statistic.

RESULTS

Six retrospective comparative articles were included in the present meta-analysis. Weight loss analysis showed a MD = 5.70 (95% CI 4.84-6.57) in favor of the OAGB procedure with a statistical significance (p = 0.00001) and no significant statistical heterogeneity (I2 = 0.00%). There was no significant RD for leak, bleeding, or marginal ulcer after the two revisional procedures. After conversion to OAGB, remission from GERD was 68.6% (81/118), and it was 80.6% (150/186) after conversion to RYGB with a RD = 0.10 (95% CI -0.04, 0.24), no statistical significance (p = 0.19), and high heterogeneity (I2 = 96%). De novo GERD was 6.3% (16/255) after conversional OAGB, and it was 0.5% (1/180) after conversion to RYGB with a RD = -0.23 (95% CI -0.57, 0.11), no statistical significance (p = 0.16), and high heterogeneity (I2 = 92%).

Is one-anastomosis gastric bypass a good revisional bariatric surgery? A single-center retrospective cohort study

<b><br>Introduction:</b> The rate of revisional surgeries following sleeve gastrectomy (SG) has increased. One-anastomosis gastric bypass (OAGB) appears to have multiple advantages as a primary bariatric procedure. OAGB as revisional surgery is still being investigated.</br> <b><br>Aim:</b> Evaluation of the efficacy and safety of OAGB performed as a post-SG revisional surgery.</br> <b><br>Materials and methods:</b> A single-center, retrospective cohort study was conducted using a routinely collected database of adults undergoing revisional OAGB after SG. A survey of patients was conducted, obtaining information on changes in body weight and improvement in gastroesophageal reflux disease (GERD) and obesity-related diseases.</br> <b><br>Results:</b> The study group included 74 patients: 59 women (80%) and 15 men, mean age of 41.61 9.21 years. The most common indication for OAGB was weight regain. The follow-up was up to 7 years, the mean time was 3.58 1.21 years. The mean preoperative body mass index (BMI) was 40.38 6.15. All patients experienced significant weight loss, reaching a BMI of 33.61 (27.28- 37.13) at the last observation. After surgery, 35% of patients achieved successful weight loss and 48% of patients achieved remission or improvement of GERD.</br> <b><br>Conclusions:</b> Revisional OAGB seems to be a good alternative after a failed SG in terms of obesity-related disease recurrence, not of weight regain. Long-term follow-up revealed that only a third of patients achieved successful weight loss. When proposing revisional OAGB, the risk of complications - mainly anemia and the possibility of de novo GERD should be considered.</br>.

The analysis of factors increasing the odds for type 2 diabetes mellitus remission following re-do bariatric surgery after laparoscopic sleeve gastrectomy- cohort study

INTRODUCTION

Metabolic/bariatric surgery is the only proven treatment for type 2 diabetes mellitus (T2D) with curative intent. However, in a number of patients, the surgery is not effective or they may experience a relapse. Those patients can be offered re-do bariatric surgery (RBS).

PURPOSE

The study aimed to determine factors increasing the odds for T2D remission one year after RBS following primary laparoscopic sleeve gastrectomy.

METHODS

A multicenter retrospective cohort study was conducted between January 2010 and January 2020, which included 12 bariatric centers in Poland. The study population was divided into groups: Group 1- patients with T2D remission after RBS (n = 28) and Group 2- patients without T2D remission after RBS (n = 49). T2D remission was defined as HBA1c < 6.0% without glucose-lowering pharmacotherapy and glycemia within normal range at time of follow-up that was completed 12 months after RBS.

RESULTS

Fifty seven females and 20 males were included in the study. Patients who achieved BMI < 33 kg/m2 after RBS and those with %EBMIL > 60.7% had an increased chance of T2D remission (OR = 3.39, 95%CI = 1.28-8.95, p = 0.014 and OR = 12.48, 95%CI 2.67-58.42, p = 0.001, respectively). Time interval between primary LSG and RBS was significantly shorter in Group 1 than in Group 2 [1 (1-4) vs. 3 (2-4) years, p = 0.023].

CONCLUSIONS

Shorter time interval between LSG and RBS may ease remission of T2D in case of lack of remission after primary procedure. Significant excess weight loss seems to be the most crucial factor for T2D remission.

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.

How Good is Stratification and Prediction Model Analysis Between Primary and Revisional Roux-en-Y Gastric Bypass Surgery? A Multi-center Study and Narrative Review

INTRODUCTIONS

Revision surgery because of weight recurrence is performed in 2.5-33% of primary vertical banded gastroplasty (VBG), laparoscopic sleeve gastrectomy (LSG), and gastric band (GB) cases. These cases qualify for revisional Roux-en-Y gastric bypass (RRYGB).

METHODS

This retrospective cohort study analyzed data from 2008 to 2019. A stratification analysis and multivariate logistic regression for prediction modeling compared the possibility of sufficient % excess weight loss (%EWL) ≥ 50 or insufficient %EWL < 50 between three different RRYGB procedures, with primary Roux-en-Y gastric bypass (PRYGB) as the control during 2 years of follow-up. A narrative review was conducted to test the presence of prediction models in the literature and their internal and external validity.

RESULTS

A total of 558 patients underwent PRYGB, and 338 underwent RRYGB after VBG, LSG, and GB, and completed 2 years of follow-up. Overall, 32.2% of patients after RRYGB had a sufficient %EWL ≥ 50 after 2 years, compared to 71.3% after PRYGB (p ≤ 0.001). The total %EWL after the revision surgeries for VBG, LSG, and GB was 68.5%, 74.2%, and 64.1%, respectively (p ≤ 0.001). After correcting for confounding factors, the baseline odds ratio (OR) or sufficient %EWL ≥ 50 after PRYGB, LSG, VBG, and GB was 2.4, 1.45, 0.29, and 0.32, respectively (p ≤ 0.001). Age was the only significant variable in the prediction model (p = 0.0016). It was impossible to develop a validated model after revision surgery because of the differences between stratification and the prediction model. The narrative review showed only 10.2% presence of validation in the prediction models, and 52.5% had external validation.

CONCLUSION

Overall, 32.2% of all patients after revisional surgery had a sufficient %EWL ≥ 50 after 2 years, compared to PRYGB. LSG had the best outcome in the revisional surgery group in the sufficient %EWL group and the best outcome in the insufficient %EWL group. The skewness between the prediction model and stratification resulted in a partially non-functional prediction model.

Management of leaks following one-anastomosis gastric bypass: an updated systematic review and meta-analysis of 44 318 patients

INTRODUCTION

One-anastomosis gastric bypass (OAGB) complication, such as leakage, can be dangerous and should be managed properly, yet little data exist in the literature regarding the management of leaks after OAGB, and there are no guidelines to date.

METHODS

The authors performed a systematic review and meta-analysis of the literature and 46 studies, examining 44 318 patients were included.

RESULTS

There were 410 leaks reported in 44 318 patients of OAGB published in the literature, which represents a prevalence of 1% of leaks after OAGB. The surgical strategy was very variable among all the different studies; 62.1% of patients with leaks had to undergo another surgery due to the leak. The most commonly performed procedure was peritoneal washout and drainage (with or without T-tube placement) in 30.8% of patients, followed by conversion to Roux-en-Y gastric bypass in 9.6% of patients. Medical treatment with antibiotics, with or without total parenteral nutrition alone, was conducted in 13.6% of patients. Among the patients with the leak, the mortality rate related to the leak was 1.95%, and the mortality due to the leak in the population of OAGB was 0.02%.

CONCLUSION

The management of leaks following OAGB requires a multidisciplinary approach. OAGB is a safe operation with a low leak risk rate, and the leaks can be managed successfully if detected in a timely fashion.

Comparison of One Anastomosis Gastric Bypass and Sleeve Gastrectomy for Revision of Laparoscopic Adjustable Gastric Banding: 5-Year Outcomes

PURPOSE

Laparoscopic adjustable gastric banding (LAGB) is in continuous decline due to low effectiveness and high reoperation rates. This study aims to evaluate outcomes of converting LAGB to one anastomosis gastric bypass (OAGB) and sleeve gastrectomy (SG) for insufficient weight loss or weight regain.

MATERIALS AND METHODS

Retrospective comparative study, based on prospective registry database of a tertiary center (2012-2019).

RESULTS

In all, 276 LAGB patients were converted to OAGB (n = 125) and SG (n = 151). Body mass index (BMI) at revision was 41.3 ± 6.6 and 42.3 ± 9.6 kg/m2 (P = 0.34) in OAGB and SG patients, respectively. Time interval was longer in OAGB patients (p < 0.001). Major early complication rates were comparable (2.4% and 4%; p = 0.46). At 5-years, OAGB patients had lower BMI (31.9 vs. 34.5 kg/m2; p = 0.002), and a higher total weight loss (25.1% vs. 18.8%; p = 0.003), compared with SG patients. Resolution of type 2 diabetes was higher in OAGB patients (93.3% vs. 66.6%; p = 0.047), while resolution of hypertension was not significantly different (84.6% and 80.5%; p = 0.68). Revision due to delayed complications was required in five (4%) OAGB patients and nine (8.6%) SG patients (p = 0.14).

CONCLUSION

OAGB for revision after LAGB due to insufficient weight loss or weight regain is safe, and has better effectiveness in weight reduction and resolution of type 2 diabetes than SG.

Weight loss specific to indication, remission of diabetes, and short-term complications after sleeve gastrectomy conversion to Roux-en-Y gastric bypass: a systematic review and meta-analysis

Laparoscopic sleeve gastrectomy (SG) is the most frequently performed bariatric procedure worldwide. Long-term complications such as insufficient weight loss (IWL) and gastroesophageal reflux disease (GERD) may necessitate SG conversion to Roux-en-Y gastric bypass (RYGB). The aim of this review was to determine the indication-specific weight loss and diabetes remission after SG conversion to RYGB (STOBY). Our objective was to extract all available published data on indication for conversion, weight loss, remission of diabetes, and short-term complications after STOBY. A systematic literature search was conducted to identify studies reporting outcomes following STOBY. A random effects model was used for meta-analysis. The search identified 44 relevant studies. Overall short-term (12-mo) excess weight loss (EWL) was 54.6% (95% confidence interval [CI], 46%-63%) in 23 studies (n = 712) and total weight loss (TWL) was 19.9% (95% CI, 14%-25%) in 21 studies (n = 740). For IWL, short-term (12-mo) pooled weight loss outcomes were 53.9% EWL (95% CI, 48%-59%) in 14 studies (n = 295) and 22.7% TWL (95% CI, 17%-28%) in 12 studies (n = 219), and medium-term (2-5 yr) outcomes were 45.8% EWL (95% CI, 38%-53%) in 7 studies (n = 154) and 20.6% TWL (95% CI, 15%-26%) in 9 studies (n = 206). Overall diabetes remission was 53% (95% CI, 33%-72%), and the perioperative complication rate was 8.2% (95% CI, 7.6%-8.7%). Revisional SG conversion to RYGB for IWL can achieve good weight loss outcomes and diabetes remission.

Best practice approach for redo-surgeries after sleeve gastrectomy, an expert's modified Delphi consensus

BACKGROUND

Sleeve gastrectomy (SG) is the most common metabolic and bariatric surgical (MBS) procedure worldwide. Despite the desired effect of SG on weight loss and remission of obesity-associated medical problems, there are some concerns regarding the need to do revisional/conversional surgeries after SG. This study aims to make an algorithmic clinical approach based on an expert-modified Delphi consensus regarding redo-surgeries after SG, to give bariatric and metabolic surgeons a guideline that might help for the best clinical decision.

METHODS

Forty-six recognized bariatric and metabolic surgeons from 25 different countries participated in this Delphi consensus study in two rounds to develop a consensus on redo-surgeries after SG. An agreement/disagreement ≥ 70.0% on statements was considered to indicate a consensus.

RESULTS

Consensus was reached for 62 of 72 statements and experts did not achieve consensus on 10 statements after two rounds of online voting. Most of the experts believed that multi-disciplinary team evaluation should be done in all redo-procedures after SG and there should be at least 12 months of medical and supportive management before performing redo-surgeries after SG for insufficient weight loss, weight regain, and gastroesophageal reflux disease (GERD). Also, experts agreed that in case of symptomatic GERD in the presence of adequate weight loss, medical treatment for at least 1 to 2 years is an acceptable option and agreed that Roux-en Y gastric bypass is an appropriate option in this situation. There was disagreement consensus on efficacy of omentopexy in rotation and efficacy of fundoplication in the presence of a dilated fundus and GERD.

CONCLUSION

Redo-surgeries after SG is still an important issue among bariatric and metabolic surgeons. The proper time and procedure selection for redo-surgery need careful considerations. Although multi-disciplinary team evaluation plays a key role to evaluate best options in these situations, an algorithmic clinical approach based on the expert's consensus as a guideline can help for the best clinical decision-making.

Safety of concomitant cholecystectomy during one anastomosis gastric bypass compared with sleeve gastrectomy and Roux-en-Y gastric bypass

Candidates of metabolic and bariatric surgery (MBS) are prone for gallstone formation. Concomitant cholecystectomy (CC) during MBS is controversial. This study is first to examine the safety of CC during one anastomosis gastric bypass (OAGB), compared with sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). Single-center retrospective comparative study of CC (2012-2021) during OAGB, to SG and RYGB. CC was performed in 115 patients during OAGB (n = 50), SG (n = 39), and RYGB (n = 26). All procedures were completed laparoscopically. Baseline characteristics were similar except age, body mass index, gastroesophageal reflux disease, obstructive sleep apnea, and previous MBS (p < 0.05). Intraoperative complications occurred in one OAGB patient (2% vs. 0%, 0%; p = 0.52), which was not cholecystectomy related. There were no differences in total (6% vs. 2.6%, 15.4%; p = 0.13) and major (2% vs. 0%, 3.8; p = 0.50) early-complication rates. Of them, cholecystectomy-related complications occurred in one OAGB, compared with none of SG and one RYGB (2% vs. 0%, 3.8%; p = 0.50). The former was major, and the latter was minor complication. None of the OAGB patients needed re-admission (0% vs. 0%, 11.5; p = 0.04). All CC outcome parameters were similar between asymptomatic and symptomatic gallstones. Previous bariatric procedures were found to be a significant risk for major complications and readmissions (OR = 16.87, p = 0.019). CC during OAGB for gallstones seems safe, as in SG and RYGB. No cholecystectomy-related intraoperative complications occurred, and postoperative complication rates were low and acceptable. Outcomes for asymptomatic gallstones were similar to symptomatic ones, and we cautiously support CC in the presence of gallstones.

Efficacy and Safety of Sleeve Gastrectomy or One Anastomosis Gastric Bypass Conversion Following Adjustable Gastric Banding

BACKGROUND

Given revision or conversion surgery is required in up to 60% of patients who had adjustable gastric band (LAGB), we compared safety and efficacy of sleeve gastrectomy (SG) and one anastomosis gastric bypass (OAGB) as conversion surgical procedures in patients with suboptimal response or weight recurrence following LAGB.

METHODS

Conversion surgery was performed in 335 patients between 2016 and 2020. Weight loss, early and late-stage complications, and comorbidity outcomes were reviewed and analyzed.

RESULTS

One hundred and sixty-three patients underwent cSG (BMI: 38.3 ± 8.3 kg/m²), and 172 patients underwent cOAGB (BMI: 45.2 ± 9.3 kg/m²). Percent total body weight loss (%TWL) was 28.7 ± 9.9% at 12 months, 30.3 ± 12.8% at 2 years, 31.0 ± 14.5% at 3 years, and 31.1 ± 14.7% at 4 years following OAGB, which was significantly higher than SG; 18.4 ± 8.7%, 18.8 ± 9.8%, 19.3 ± 11.1%, and 16.9 ± 10.9%, respectively (p < 0.0001). Remission of comorbidities, regardless of conversion procedure type, was 20.8% for hypertension (HT), 52% for dyslipidemia (DLD), 60% for type 2 diabetes (DM), 64% for non-alcoholic steatohepatitis (NASH), and 76% for insulin resistance (IR).There were no leaks or deaths following SG or OAGB. A twofold greater frequency of complications was seen in the OAGB group vs SG group (15.1% and 6.7%, respectively).

CONCLUSION

Significant weight loss, acceptable complication rates, and similar remission of comorbidities were seen regardless of the type of conversion procedure. Prospective randomized clinical trials are recommended for further elucidation of long-term outcomes.

One Anastomosis Gastric Bypass Compared with Sleeve Gastrectomy in Elderly Patients: Safety and Long-term Outcomes

BACKGROUND

As life expectancy increases, more elderly patients are being considered for metabolic bariatric surgery. We aimed to assess the safety and long-term effectiveness of one anastomosis gastric bypass (OAGB) compared to sleeve gastrectomy (SG).

METHODS

Single-center retrospective comparative study of OAGB and SG (2012-2019) in patients aged ≥ 65 years.

RESULTS

In all, 124 patients underwent OAGB (n = 41) and SG (n = 83). Mean age was 67.6 ± 2.8 and 67.6 ± 2.6 years (p = 0.89), respectively. Baseline characteristics were comparable, except lower rates of hypertension (HTN) and non-alcoholic fatty liver disease in OAGB than SG patients (43.9% vs. 74.6%; p < 0.001, and 39.0% vs. 89.1%; p < 0.001, respectively). Body mass index (BMI) of OAGB and SG patients decreased from 41.8 ± 7.8 and 43.3 ± 5.9 kg/m² (p = 0.25) to 28.6 ± 4.7 and 33.2 ± 5.3 (p < 0.001), at long-term follow-up, respectively. Excess weight loss (EWL) > 50% was achieved in 80.6% and 43.2% of OAGB and SG patients, with a mean EWL of 67.2% ± 22.3 and 45.8% ± 18.0 (p < 0.001) and a mean total weight loss (TWL) of 30.7% ± 10.4 and 21.9% ± 8.1 (p < 0.001), respectively. Resolution rates of obesity-associated medical problems were similar, except type 2 diabetes (T2D) and HTN, which were 86.6% and 73.3% in OAGB, compared with 29.7% and 36.3% in SG patients (p < 0.001 and p = 0.001), respectively. Major early complication rates were comparable (2.4% vs. 3.6%; p = 0.73, respectively). Revision for late complications was required in two OAGB patients.

CONCLUSIONS

OAGB in the elderly is safe and results in better long-term weight reduction and resolution of T2D and HTN than SG.

Long-term outcomes of revisional one anastomosis gastric bypass post laparoscopic sleeve gastrectomy

PURPOSE

Revisional bariatric surgeries following laparoscopic sleeve gastrectomy (LSG) have demonstrated a dramatic increase worldwide. Recently, one-anastomosis gastric bypass (OAGB) has become a contender as an appropriate revisional procedure; however, no long-term data currently exist on the effectiveness of it as a revisional surgery post-LSG.

METHODS

A retrospective analysis was performed on all patients who underwent LSG at a public hospital in Kuwait from 2008 to 2017. A list was obtained of those who underwent revisional OAGB surgery after initial LSG, after which a phone survey was performed and demographics were analyzed.

RESULTS

A total of 29 patients underwent revisional OAGB post-initial LSG, of which 89.7% were female. Prior to LSG, the mean weight of the patients was 127.5 kg, and the mean BMI was 49.0 kg/m2. The mean weight loss after initial LSG was 43.8 kg, while the average duration until patients underwent revisional OAGB was 5.3 years. The cause for revision was weight regain (86.2%) or inadequate weight loss (13.8%). Prior to undergoing revisional OAGB, the weight and BMI of the patients was 110.9 kg and 42.4 kg/m2, respectively. Revisional OAGB demonstrated a %excess weight loss of 14.5%, 31.9%, 48.0%, 56.3%, 57.2%, and 54.7% at 2 weeks, 3 months, 6 months, 1 year, 4 years, and 5 years, respectively. Twelve morbidities were reported during the follow-up period.

CONCLUSION

Revisional bariatric surgery is technically demanding and may be associated with a high complication rate. However, OAGB as a revisional procedure has proven to be safe and effective in the long-term outcomes of revisional OAGB patients post-LSG.

Micronutrients Deficiencies in Candidates of Bariatric Surgery: Results from a Single Institution over a 1-Year Period

BACKGROUND

Micronutrient deficiencies represent a common condition after bariatric surgery (BS). The prevalence of these nutritional disorders before BS is still debated. The aim of our study was to retrospectively evaluate the prevalence of micronutrient deficiencies in candidates for BS.

METHODS

A prospectively maintained database of our institution was searched to find all patients who underwent surgery between January and December 2021. The following data were collected: age, gender, body mass index (BMI), obesity-associated diseases, and preoperative serum levels of vitamin B12, folate, and vitamin D.

RESULTS

A total of 174 patients were included in our study. Mean age and BMI were 39.2 ± 11.4 years and 44.3 ± 7.1 kg/m², respectively. One hundred and thirty-nine patients (79.9%) had at least one preoperative micronutrient disorder, with vitamin D deficiency being the most common (116, 66.7%), followed by a deficit of folate (76, 43.7%) and vitamin B12 (10, 5.7%). Forty-seven (27%) individuals had insufficient levels of vitamin D. Comparison of deficiencies between sexes showed that vitamin B12 < 20 ng/ml was significantly more frequent in women (p = 0.03). DLP showed a mild significant effect on folate levels (p = 0.01), while the association of HNT and T2DM had a mild significant effect on vitamin B12 (p = 0.02).

CONCLUSIONS

Preoperative micronutrient deficiencies were frequently found in candidates for BS. Approximately 90% of patients had deficient or insufficient serum levels of vitamin D preoperatively. Almost half of the patients had a preoperative deficit of folate, and vitamin B12 deficiency was significantly more frequent in the female population. It is mandatory to screen all patients undergoing BS for vitamin deficiencies before surgery.

[Therapeutic Options for Regaining Weight after Bariatric Surgery]

PURPOSE

The purpose of this article is to create an overview of diagnostic and therapeutic options for weight regain (WR) and insufficient weight loss (IWL) after bariatric surgery (BS). With increasing popularity of BS, WR is becoming more relevant.

METHODS

We combined recent literature on WR and IWL with personal experience to suggest possible proceedings if WR or IWL is diagnosed.

RESULTS

If an anatomical-pathological cause can be detected, surgical therapy is the most effective. If WR or IWL is idiopathic, a multimodal therapeutic concept is necessary for sufficient therapeutic success. Depending on the initial BS, a combination of lifestyle intervention, medication and surgical therapy seems most effective.

CONCLUSIONS

Extensive diagnostic testing is necessary prior to any surgical intervention. In idiopathic WR after Roux-en-Y Gastric Bypass (RYGB), we suggest lengthening the biliopancreatic limb and shortening the common channel. After Sleeve-Gastrectomy (SG), we currently see RYGB as most effective in patients with gastroesophageal reflux disease (GERD) and SADI-S as a feasible option if no GERD is present.

One Anastomosis Gastric Bypass for Revision of Restrictive Procedures: Mid-Term Outcomes and Analysis of Possible Outcome Predictors

PURPOSE

Revisional one anastomosis gastric bypass (OAGB) for insufficient weight reduction following primary restrictive procedures is still investigated. We report mid-term outcomes and possible outcome predictors.

MATERIALS AND METHODS

Single-center retrospective comparative study of revisional OAGB outcomes (2015-2018) following laparoscopic adjustable gastric banding (LAGB) and sleeve gastrectomy (SG); silastic ring vertical gastroplasty (SRVG) is separately discussed.

RESULTS

In all, 203 patients underwent revisional OAGB following LAGB (n = 125), SG (n = 64), and SRVG (n = 14). Comparing LAGB and SG, body mass index (BMI) at revision were 41.3 ± 6.6 and 42 ± 11.2 kg/m² (p = 0.64), reduced to 31.3 ± 8.3 and 31.9 ± 8.3 (p = 0.64) at mid-term follow-up, respectively. Excess weight loss (EWL) > 50% was achieved in ~ 50%, with EWL of 79.4 ± 20.4% (corresponding total weight loss 38.5 ± 10.4%). SRVG patients had comparable outcomes. Resolution rates of type 2 diabetes (T2D) and hypertension (HTN) were 93.3% and 84.6% in LAGB compared with 100% and 100% in SG patients (p = 0.47 and p = 0.46), respectively. In univariable analysis, EWL > 50% was associated with male gender (p < 0.001), higher weight (p < 0.001), and BMI (p = 0.007) at primary surgery, and higher BMI at revisional OAGB (p < 0.001). In multivariable analysis, independent predictors for EWL > 50% were male gender (OR = 2.8, 95% CI 1.27-6.18; p = 0.01) and higher BMI at revisional OAGB (OR = 1.11, 95% CI 1.03-1.19; p = 0.006).

CONCLUSION

Revisional OAGB for insufficient restrictive procedures results in excellent weight reduction in nearly 50% of patients, with resolution of T2D and HTN at mid-term follow-up. Male gender and higher BMI at revision were associated with EWL > 50% following revisional OAGB. Identification of more predictors could aid judicious patient selection.

Exploring the landscape, hot topics, and trends of bariatric metabolic surgery with machine learning and bibliometric analysis

Background

This study aimed to analyze the landscape of publications on bariatric metabolic surgery through machine learning and help experts and scholars from various disciplines better understand bariatric metabolic surgery's hot topics and trends.

Methods

In January 2021, publications indexed in PubMed under the Medical Subject Headings (MeSH) term 'Bariatric Surgery' from 1946 to 2020 were downloaded. Python was used to extract publication dates, abstracts, and research topics from the metadata of publications for bibliometric evaluation. Descriptive statistical analysis, social network analysis (SNA), and topic modeling with latent Dirichlet allocation (LDA) were used to reveal bariatric metabolic surgery publication growth trends, landscape, and research topics.

Results

A total of 21,798 records of bariatric metabolic surgery-related literature data were collected from PubMed. The number of publications indexed to bariatric metabolic surgery had expanded rapidly. Obesity Surgery and Surgery for Obesity and Related Diseases are currently the most published journals in bariatric metabolic surgery. The bariatric metabolic surgery research mainly included five topics: bariatric surgery intervention, clinical case management, basic research, body contour, and surgical risk study.

Conclusion

Despite a rapid increase in bariatric metabolic surgery-related publications, few studies were still on quality of life, psychological status, and long-term follow-up. In addition, basic research has gradually increased, but the mechanism of bariatric metabolic surgery remains to be further studied. It is predicted that the above research fields may become potential hot topics in the future.

Five-year outcomes of one anastomosis gastric bypass as conversional surgery following sleeve gastrectomy for weight loss failure

The most accepted procedures as conversion for poor weight changes after sleeve gastrectomy (SG), are malabsorptive surgeries. This study was designed to evaluate the 5-year outcomes of One Anastomosis Gastric Bypass (OAGB) following SG due to weight loss failure and weight regain. From September 2014 to January 2017, totally 23 patients with a history of SG conversion to OAGB in terms of weight loss failure or weight regain who had completed their 5-year follow-ups were studied. Some obesity related co-morbidities containing type-2 diabetes (DM), hypertension (HTN), dyslipidemia, obstructive sleep apnea (OSA) and gastroesophageal reflux disease (GERD) were also investigated at 1, 2, 3 and 5 years after conversional surgery. All cases had remission/improvement in DM, DLP, HTN and OSA 1 year after conversional OAGB. Analysis showed statistically significant (P < 0.001) change in trend of BMI. Mean BMI before conversional surgery, at 1, 2, 3and 5 years were 46.3 ± 10.4, 34.5 ± 8.5, 34.1 ± 8.6, 35.7 ± 8.7 and 37.5 ± 11.6, respectively. Mean percent excess weight loss (%EWL) at 1, 2, 3 and 5 years was 51.6 ± 11.0, 52.9 ± 13.1, 45.5 ± 16.4 and 41.0 ± 18.0, respectively. Mean percent total weight loss (%TWL) at 1, 2, 3 and 5 years was 26.6 ± 5.9, 27.4 ± 7.2, 23.9 ± 9.2 and 20.9 ± 9.3, respectively. OAGB is an effective conversional procedure for insufficient weight loss and weight regain following failed SG and lead to satisfactory changes in obesity associated medical problems. The optimal weight loss results are obtained at 2-year follow-ups and these effects are then reduced.

Patient Selection in One Anastomosis/Mini Gastric Bypass-an Expert Modified Delphi Consensus

PURPOSE

One anastomosis/mini gastric bypass (OAGB/MGB) is up to date the third most performed obesity and metabolic procedure worldwide, which recently has been endorsed by ASMBS. The main criticisms are the risk of bile reflux, esophageal cancer, and malnutrition. Although IFSO has recognized this procedure, guidance is needed regarding selection criteria. To give clinicians a daily support in performing the right patient selection in OAGB/MGB, the aim of this paper is to generate clinical guidelines based on an expert modified Delphi consensus.

METHODS

A committee of 57 recognized bariatric surgeons from 24 countries created 69 statements. Modified Delphi consensus voting was performed in two rounds. An agreement/disagreement among ≥ 70.0% of the experts was considered to indicate a consensus.

RESULTS

Consensus was achieved for 56 statements. Remarkably, ≥ 90.0% of the experts felt that OAGB/MGB is an acceptable and suitable option "in patients with Body mass index (BMI) > 70, BMI > 60, BMI > 50 kg/m² as a one-stage procedure," "as the second stage of a two-stage bariatric surgery after Sleeve Gastrectomy for BMI > 50 kg/m² (instead of BPD/DS)," and "in patients with weight regain after restrictive procedures. No consensus was reached on the statement that OAGB/MGB is a suitable option in case of resistant Helicobacter pylori. This is likely as there is a concern that this procedure is associated with reflux and its related long-term complications including risk of cancer in the esophagus or stomach. Also no consensus reached on OAGB/MGB as conversional surgery in patients with GERD after restrictive procedures. Consensus for disagreement was predominantly achieved "in case of intestinal metaplasia of the stomach" (74.55%), "in patients with severe Gastro Esophageal Reflux Disease (GERD)(C,D)" (75.44%), "in patients with Barrett's metaplasia" (89.29%), and "in documented insulinoma" (89.47%).

CONCLUSION

Patient selection in OAGB/MGB is still a point of discussion among experts. There was consensus that OAGB/MGB is a suitable option in elderly patients, patients with low BMI (30-35 kg/m²) with associated metabolic problems, and patients with BMIs more than 50 kg/m² as one-stage procedure. OAGB/MGB can also be a safe procedure in vegetarian and vegan patients. Although OAGB/MGB can be a suitable procedure in patients with large hiatal hernia with concurrent hiatal hernia, it should not be offered to patients with grade C or D esophagitis or Barrett's metaplasia.

Single-Anastomosis Sleeve Jejunal (SAS-J) Bypass as Revisional Surgery After Primary Restrictive Bariatric Procedures

Purpose

Single-anastomosis sleeve jejunal (SAS-J) bypass is the modification of a single-anastomosis sleeve ileal (SASI) bypass with a short biliary limb. SAS-J bypass is reported to be a good primary bariatric procedure. This study aimed to evaluate the results of SAS-J bypass as a revisional surgery after failed primary restrictive bariatric procedures.

Material and Methods

This was a prospective cohort study including 43 patients who underwent SAS-J bypass as a revisional surgery for weight regain after laparoscopic sleeve gastrectomy (LSG), laparoscopic adjustable gastric band (LAGB), or laparoscopic gastric plication.

Results

Of the total patients, 35 (81.4%) were female, and 8 (18.6%) were male. The mean BMI was 46.3 kg/m². The mean age was 41 years. Thirty-two patients (74.4%) had a failed sleeve, 9 (20.9%) had a failed LAGB, and 2 (4.7%) had a failed gastric plication. The mean operative time was 104 min. Intra-abdominal bleeding occurred in 1 case (2.3%), and intraluminal bleeding occurred in 3 cases (7%). No case (0%) developed a leak. The percentage of excess weight loss (%EWL) reached 76.5% after 1 year. Type 2 diabetes mellitus remission occurred in all diabetic patients, hypertension remitted in 80%, hyperlipidemia remitted in 83.3%, and obstructive sleep apnea syndrome improved in all cases. Gastroesophageal reflux disease (GERD) symptoms were improved in 86.7% of patients. Significant biliary gastritis occurred in 4 patients (9.3%). Dumping syndrome was reported in 4 patients (9.3%).

Conclusions

SAS-J bypass was effective as a salvage surgery after failed restrictive bariatric procedures, but long-term follow-up is needed.

Graphical abstract

Re-Do Surgery after Sleeve Gastrectomy: A Single Center Comparison between Roux-en-Y Gastric Bypass and One Anastomosis Gastric Bypass

Introduction: According to the high rate of patients requiring a Re-Do surgery after a primary Sleeve Gastrectomy, due to failure on weight loss, this study proposes a comparison between RYGB and OAGB as a secondary intervention for morbidly obese patients. Methods: A retrospective review of patients who underwent revisional surgery to convert SG to RYGB or OAGB at our institution from November 2011 to November 2019 was performed. Results: A subset of sixty-three patients with previous SG underwent revisional surgery due to failure of the primary intervention. The OAGB group (n = 17) had a mean BMI at the time of the sleeve of 62 kg/m2 and a mean BMI of 50.7 kg/m2, the length of the Omega was 139.35 cm. The RYGB (n = 46) group showed a mean BMI of 47 kg/m2 at the time of the sleeve and a BMI of 34.8 kg/m2 at the time of the revision. The RYGB was performed according to the 70/120 cm standard for all the patients. One patient also had a revision from secondary OAGB to RYGB due to persistent biliary reflux, in this case the biliary branch was settled at 150 cm and the alimentary at 50 cm. Conclusions: The outcomes in the OAGB group showed a 29%WL and a 47%EWL (out of a 17%WL and 28%EWL at the time of the sleeve), on the other side the RYGB group reached a 33%WL and 72%EWL (out of a 25%WL and a 54%EWL at the time of the sleeve). According to our data we assume that RYGB is more effective in terms of weight loss as a revisional surgery after sleeve

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

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

Gastric Remnant Mucocele after Conversion of Vertical Band Gastroplasty to One Anastomosis Gastric Bypass: a Video Vignette

Conversional bariatric surgery is a challenging procedure to patients as well as the surgeon. One anastomosis gastric bypass (OAGB) is a known safe conversional procedure after primary restrictive weight loss surgeries such as vertical banded gastroplasty (VBG). A very rare reported complication after these operations is the formation of mucocele of gastric remnant during pouch creation. This is a video report of diagnosis and management of gastric remnant mucocele after conversion of VBG to OAGB.

Revisional Surgery After One Anastomosis/Minigastric Bypass: an Italian Multi-institutional Survey

BACKGROUND

Efficacy and safety of OAGB/MGB (one anastomosis/mini gastric bypass) have been well documented both as primary and as revisional procedures. However, even after OAGB/MGB, revisional surgery is unavoidable in patients with surgical complications or insufficient weight loss.

METHODS

A questionnaire asking for the total number and demographics of primary and revisional OAGB/MGBs performed between January 2006 and July 2020 was e-mailed to all S.I.C. OB centres of excellence (annual caseload > 100; 5-year follow-up > 50%). Each bariatric centre was asked to provide gender, age, preoperative body mass index (BMI) and obesity-related comorbidities, previous history of abdominal or bariatric surgery, indication for surgical revision of OAGB/MGB, type of revisional procedure, pre- and post-revisional BMI, peri- and post-operative complications, last follow-up (FU).

RESULTS

Twenty-three bariatric centres (54.8%) responded to our survey reporting a total number of 8676 primary OAGB/MGBS and a follow-up of 62.42 ± 52.22 months. A total of 181 (2.08%) patients underwent revisional surgery: 82 (0.94%) were suffering from intractable DGER (duodeno-gastric-esophageal reflux), 42 (0.48%) were reoperated for weight regain, 16 (0.18%) had excessive weight loss and malnutrition, 12 (0.13%) had a marginal ulcer perforation, 10 (0.11%) had a gastro-gastric fistula, 20 (0.23%) had other causes of revision. Roux-en-Y gastric bypass (RYGB) was the most performed revisional procedure (109; 54%), followed by bilio-pancreatic limb elongation (19; 9.4%) and normal anatomy restoration (19; 9.4%).

CONCLUSIONS

Our findings demonstrate that there is acceptable revisional rate after OAGB/MGB and conversion to RYGB represents the most frequent choice.

Minimally invasive gastrointestinal surgery: From past to the future

The improvement of the science and art of surgery began over 150 years ago. Surgical core tasks, “cutting and sewing” with hand and direct contact with the organs, have remained the same. However, in the 21st century, there has been a shifting paradigm in the methodology of surgery. The joint union between innovators, engineers, industry, and patient demands resulted in minimally invasive surgery (MIS). This method has influenced the techniques in every aspect of abdominal surgery, such as surgeons are not required to direct contact or see the structures on which they operate. Advances in the endoscope, imaging, and improved instrumentations convert the essential open surgery into the endoscopic method. Furthermore, computers and robotics show a promising future to facilitate complex procedures, enhance accuracy in microscale operations, and develop a simulation to improve the ability to face sophisticated approaches. MIS has been replacing open surgery due to improved survival, fewer complications, and rapid recoveries in recent years. Minimally invasive surgery's further research in diagnostic and therapeutic modalities is under investigation to achieve genuinely “noninvasive” surgery. Thus, MIS has gained interest in recent days and has been improving with promising outcomes.

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Minimally invasive surgery has interfered with multiple aspects of the surgical approach.

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Advancement in the endoscope, imaging, and other instrumentations shifting the current methodological conventional surgery.

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The benefit over risk is the promising primary outcome to achieve an exceptional quality of life.

Impact of COVID-19 Lockdown on Short-term Weight Loss in a Single Italian Institution

Italy was the first European country to have a major outbreak of COVID-19. Bariatric procedures were stopped and telemedicine had to be implemented. A large percentage of patients struggled to follow postoperative diet and to start physical activity due to social restrictions. We have compared short-term outcomes of patients who had bariatric procedures prior to lockdown with subjects that had undergone obesity surgery in the same period of the previous year at our institution. A total number of 63 patients were included in this study. Weight loss at 1, 3 and 6 postoperative months in the 2019 group was significantly higher at any point of follow-up when compared to 2020. Social limitations and nonattendance of clinical appointments may have compromised early results.

Roux-en-Y gastric bypass versus one anastomosis-mini gastric bypass as a rescue procedure following failed restrictive bariatric surgery. A systematic review of literature with metanalysis

BACKGROUND

Although different procedures have been proposed as revisional surgery for patients who had previously undergone a failed primary restrictive procedure, the ideal revisional procedure is still a matter of debate.

METHODS

A systematic search was performed in all electronic databases to find studies comparing one anastomosis-mini gastric bypass (OAGB-MGB) or Roux-en-Y gastric bypass (RYGB) as revisional bariatric surgery for weight regain or intolerance/complications of a primary restrictive procedure. The data regarding sample size, patients' gender, age, primary surgery type, number of perioperative complications, operative time, pre- and post-revisional body mass index (BMI), and excess weight loss % (EWL%) at 1-year follow-up were extracted. Five studies were included in the analysis.

RESULTS

The primary bariatric procedures were represented by vertical banded gastroplasty (VBG), laparoscopic adjustable gastric band (LAGB) and laparoscopic sleeve gastrectomy (LSG). About perioperative complications, both RYGB and OAGB-MGB showed a similar rate of leaks but OAGB-MGB had a lower rate of bleedings; considering the progression from pre- to post-revisional BMI, OAGB-MGB reveals a better outcome as well as a shorter operative time.

CONCLUSIONS

Our meta-analysis has shown OAGB-MGB, used as revisional intervention after failed restrictive surgery, achieves outcomes comparable to RYGB in terms of perioperative complications providing a simpler and more effective technique.