top of page

IFSO Consensus on definitions and clinical practice guidelines (part 3)

In the third part of our report from Hamburg, topics under discussion included long-term outcomes from surgery, RYGB vs SG, Long-term results from OAGB , algorithm to choose the best operation and revisional surgery after RYGB , and more. The following are the brief highlights from the presentations.

Long-term results from MBS

In the sessions on MBS, Ahmad Bashir (Jordan Hospital, Amman, Jordan) began the presentations by reporting on the long-term results of one anastomosis gastric bypass (OAGB), laparoscopic adjustable gastric band (LAGB) and one anastomosis duodenal switch-like sleeve gastrectomy with single anastomosis duodenoileostomy SADI-S.

For OAGB, he cited the RCT by Jain et al (LSG vs MGB-OAGB: five-year Followup Data and Comparative Outcome of the Two Procedures over Long Term-Results of a Randomised Control Trial. Obes Surg. 2021 Mar;31(3):1223-1232) that reported excess weight loss of 65.28±13.98%, TWL of 37.35±16.49 kg and EBMIL of 62.09 ± 12.72%, at five years. In addition, OAGB was found to resolve diabetes in 85% (p<0.2) of patients and had higher BAROS QoL scores compared to LSG, while the comorbidity score was 1.84±0.68 in the OAGB group vs. 2.24±0.62 LSG group at five years.

In addition, a systematic review by De Luca et al (IFSO Update Position Statement on One Anastomosis Gastric Bypass (OAGB). Obesity Surgery 31, 3251–3278 (2021) including 23,341 patients with 55.4% follow-up at five years reported EWL of 67.85%, EBMIL of 87.54 % and mean change in BMI of 13.9 kg/m2. Furthermore, type 2 diabetes was resolved in 89.6% of patients and hypertension in 74% of patients at three years. The early (30 days) complication rate was 6.3%, reoperation 1.34% and late mortality 0.042%. These findings underpin the need for long-term RCTs.

A meta-analysis (O'Brien et al. Long-Term Outcomes After Bariatric Surgery: a Systematic Review and Meta-analysis of Weight Loss at 10 or More Years for All Bariatric Procedures and a Single-Centre Review of 20-Year Outcomes After Adjustable Gastric Banding. Obes Surg. 2019 Jan;29(1):3-14) with 20-year follow-up from 1002/8485 (11.8%) LAGB patients mean EWL was 45.9% (27-66%), however, the paper also reported a mean reoperation rate of 47.8% (8-78%), pouch enlargement of 29.9%, port/tubing of 21.4%, conversions in 8.6% and erosions in 3.2%. Dr Bashir noted that the authors attribute higher rates to band type, despite others reporting similar poor outcomes. O’Brien et al reported a 29.8% complication rate with 26% of patients requiring a reoperation, 25% of patients unable to achieve 25% EWL and 35.3% unable to achieve an improvement in metabolic syndrome. Bashir asked: “Is it (LAGB) still a valid option or should we consider it a historical procedure?”

A meta-analysis by Verhoeff et al. (Evaluation of Metabolic Outcomes Following SADI-S: a Systematic Review and Meta-analysis. Obes Surg. 2022 Apr;32(4):1049-1063), which assessed the safety and efficacy of SADI-S vs other procedures including LRYGB, OAGB and BPD-DS, showed SADI-S had a TWL of 37.3% vs 35.6% for others (37.6% for BPD-DS group who had longer follow up). SADI-S had ADEK deficiencies of 12.6%, 32.1%, 0.0%, 0.5% and 3.4%, respectively, with 5% hypoalbuminemia. The reoperation rate was 0-4.5% vs 3.3-3.9% for others and the overall complication rate was 9.6-15% for SADI-S vs. 8.2-11.3% for others. Diabetes remission was lower in the SADI-S group (62.9% vs 86.7%), with hypertension, sleep apnoea and lipids were similar between the groups (63.2-73%% vs. 60.3- 74.3%).

RCT studies: RYGB vs SG

Dr Paulina Salminen (University of Turku and Turku University Hospital, Turku, Finland) reviewed the outcomes from RCT comparing RYGB with LSG and emphasised the importance of the design of clinical trials.

She began her presentation by highlighting four trials with limitations; Kehagias et al (Randomized clinical trial of laparoscopic Roux-en-Y gastric bypass versus laparoscopic sleeve gastrectomy for the management of patients with BMI < 50 kg/m2. Obes Surg. 2011 Nov;21(11):1650-6), Keidar et al (Roux-en-Y gastric bypass vs sleeve gastrectomy for obese patients with type 2 diabetes: a randomised trial. Diabetologia. 2013 Sep;56(9):1914-8), Zhang et al (A randomized clinical trial of laparoscopic Roux-en-Y gastric bypass and sleeve gastrectomy for the treatment of morbid obesity in China: a five-year outcome. Obes Surg. 2014 Oct;24(10):1617-24) and Ignat et al Randomized trial of Roux-en-Y gastric bypass versus sleeve gastrectomy in achieving excess weight loss. Br J Surg. 2017 Feb;104(3):248-256). She explained that the study by Kehagias had a primary outcome of %EWL but with no power calculation, the trial by Zhang had no power calculation, the study by Ignat did not assess differences between groups, and Keidar’s trial provided no long-term data available.

The Oseberg trial by Hofsø et al (Gastric bypass versus sleeve gastrectomy in patients with type 2 diabetes (Oseberg): a single-centre, triple-blind, randomised controlled trial. Lancet Diabetes Endocrinol. 2019 Dec;7(12):912-924), was a well-designed study that found RYGB was superior to SG for remission of type 2 diabetes one year after surgery (RYGB 75% (40/53) vs. SG 48% (26/54)), and the two procedures had a similar beneficial effect on β-cell function.

The five-year outcomes from the merged data from two RCT, SLEEVEPASS and BM-BOSS (Wölnerhanssen et al. Laparoscopic Roux-en-Y gastric bypass versus laparoscopic sleeve gastrectomy: five-year outcomes of merged data from two randomized clinical trials (SLEEVEPASS and SM-BOSS). Br J Surg. 2021 Jan 27;108(1):49-57), reported that although LRYGB induced greater weight loss and better amelioration of hypertension than LSG, there was no difference in remission of T2DM, obstructive sleep apnoea, or QoL at five years. There were more complications after RYGB, but the individual burden for patients with complications was similar after both operations.

Ten-year outcomes from the SLEEVEPASS trial (Salminen et al. Effect of Laparoscopic Sleeve Gastrectomy vs Roux-en-Y Gastric Bypass on Weight Loss, Comorbidities, and Reflux at 10 Years in Adult Patients With Obesity: The SLEEVEPASS Randomized Clinical Trial. JAMA Surg. 2022;157(8):656–666) revealed %EWL was greater after LRYGB and the procedures were not equivalent for weight loss, but both LSG and RYGB resulted in good and sustainable weight loss. There was no statistically significant difference in type 2 diabetes remission (26% and 33%, respectively; p=0.63), dyslipidaemia (19% and 35%, respectively; p=0.23) or obstructive sleep apnea (16% and 31%, respectively; p=0.30), between the procedures. However, esophagitis was more prevalent after SG (SG 30.7% vs. RYGB 7.1% (p<0.001)), but the cumulative incidence of Barrett’s esophagus was markedly lower than in previous trials, and similar after both procedures SG (4.4% vs. RYGB 3.5% (p=0.287)).

She concluded that ongoing and future studies (BEST (Sweden) and By-BandSleeve (UK)) may reveal important outcomes between the two procedures.

The other evidence for RYGB and SG

In his presentation, Professor Francesco Rubino (King’s College, London, UK) looked at the additional evidence from mechanistic studies (animal models, humans), clinical outcome studies (longterm outcomes, hard endpoints) and the cost-effectiveness of both procedures.

In an animal study, Patel et al (Surgical control of obesity and diabetes: the role of intestinal vs. gastric mechanisms in the regulation of body weight and glucose homeostasis. Obesity (Silver Spring). 2014 Jan;22(1):159-69) compared the effects of intestinal bypass alone (duodenal-jejunal bypass -DJB) and gastric resection alone (SG) in Zucker Diabetic Fatty (ZDF) rats. The outcomes revealed that SG significantly suppressed plasma ghrelin and increased insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide and peptide YY response to oral glucose whereas DJB had no effects on postprandial levels of these hormones. DJB restored postprandial glucagon suppression in diabetic rats whereas SG did not affect glucagon response.

The combination procedure (SG + DJB) induced greater weight loss and better GT than SG alone without reducing food intake further. The findings reveal a dominant role of the stomach in the regulation of body weight and incretin response to oral glucose whereas intestinal bypass primarily affects glucose homeostasis by a weight-, insulin- and incretin-independent mechanism.

An analysis of the STAMPEDE trial (Kashyap et al. Metabolic effects of bariatric surgery in patients with moderate obesity and type 2 diabetes: analysis of a randomized control trial comparing surgery with intensive medical treatment. Diabetes Care. 2013 Aug;36(8):2175-82) showed that despite similar weight loss as sleeve gastrectomy, RYGB uniquely restores beta-cell function and reduced truncal fat.

Rubino cited the long-term outcomes from three clinical studies that showed more favourable outcomes for RYBG. The first paper by McTigue et al (Comparing the five-year Diabetes Outcomes of Sleeve Gastrectomy and Gastric Bypass: The National PatientCentered Clinical Research Network (PCORNet) Bariatric Study. JAMA Surg. 2020 May 1;155(5)) revealed that patients who had RYGB had greater weight loss, a slightly higher T2DM remission rate, less T2DM relapse and better long-term glycaemic control, compared with those who had SG. The second study by Aminian et al (Late Relapse of Diabetes After Bariatric Surgery: Not Rare, but Not a Failure. Diabetes Care. 2020 Mar;43(3):534-540) revealed the independent baseline predictors of late relapse were a preoperative number of diabetes medications, duration of T2DM before surgery, and SG versus RYGB (with greater relapse of diabetes after SG). Furthermore, patients who relapsed lost less weight during the 1st year after surgery and regained more weight afterwards. The third study by Altieri et al (Rate of revisions or conversion after bariatric surgery over 10 years in the state of New York. Surg Obes Relat Dis. 2018 Apr;14(4):500-507) showed that revision rates were almost double for after SG (9.8%) than after RYGB (4.9%), and the indications were GERD, T2DM recurrence and weight regain.

He then looked at the cost effectiveness of MBS and the impact on medications, citing the study by Howard et al. (Medication Use for Obesity Related Comorbidities After Sleeve Gastrectomy or Gastric Bypass. JAMA Surg. 2022;157(3):248–256) that reported gastric bypass was associated with a slightly higher incidence of discontinuing diabetes, hypertension, or hyperlipidaemia medication up to five years after surgery, compared with sleeve gastrectomy. Patients who underwent gastric bypass also had a lower incidence of medication restart for all three medication classes. The three-year outcomes from the STAMPEDE trial by Schauer et al (Bariatric surgery versus intensive medical therapy for diabetes – three-year outcomes. N Engl J Med. 2014 May 22;370(21):2002-13) showed patients in the gastric-bypass group required fewer glucose-lowering medications per day than did those in the sleeve-gastrectomy group (0.48±0.80 vs. 1.02±1.01) and the proportion of patients who were not taking any glucose-lowering medications was significantly higher in the gastric-bypass group than in the sleeve-gastrectomy group. The number of patients no longer taking cardiovascular medications was also higher in the RYGB cohort vs the SG cohort. In addition, Varban et al (Financial Impact of Metabolic Surgery on Prescription Diabetes Medications in Michigan. JAMA Surg. 2023 Mar 1:e227749) reported that the mean decrease in diabetes prescription payments made by the insurance provider was $4133 per patient ($6736 for RYGB and $3409 for SG) in the 360 days post-surgery vs. with the 360 days pre-surgery.

Finally, Doumouras et al (Association Between Bariatric Surgery and All-Cause Mortality: A Population-Based Matched Cohort Study in a Universal Health Care System. Ann Intern Med. 2020 Nov 3;173(9):694-703), who reported on the association between MBS and all-cause mortality, found surgery was associated with substantially lower all-cause, cardiovascular, and cancer mortality, with RYGB resulting in reduced mortality vs. SG.

Rubino concluded that the clinical evidence from non-RCTs suggests better overall results for RYGB, when compared to SG, as RYGB has a greater impact on glucose metabolism, less medication usage (diabetes and CV), a better long-term remission of diabetes and lower risk of diabetes recurrence after remission, and a greater reduction in medical care cost.

Long-term results from OAGB

Professor Jean-Marc Chevallier (IFSO-EC President) said that the one-anastomosis gastric bypass (OAGB-MGB) has been widely adopted across the world and there is consensus among surgeons regarding its utilisation, safety and effectiveness (Ramos et al IFSO (International Federation for Surgery of Obesity and Metabolic Disorders) Consensus Conference Statement on One-Anastomosis Gastric Bypass (OAGBMGB): Results of a Modified Delphi Study. Obes Surg. 2020 May;30(5):1625-1634).

The long-term outcomes from OAGB showed (Parmar CD, Mahawar KK. OAGB is now an established Bariatric Procedure: a Systematic Review of 12,807 Patients. Obes Sur 2018;28: 2956-67) %EWL at five years was 70%, 72%, 75.6% and 85%, demonstrating the durability of the procedure.

However, a paper by Nehmeh et al (Acid Reflux Is Common in Patients With Gastroesophageal Reflux Disease After One-Anastomosis Gastric Bypass. Obes Surg. 2021 Nov;31(11):4717-4723) highlighted that malnutrition appears to be the main cause of revisional surgery (36.46%) and that there was a correlation between BPL length and the incidence of malnutrition (92.3% of reoperations for malnutrition were associated with BPL length of over 200 cm). In addition, OAGB was found to have a higher risk of anaemia than RYGB, and acid reflux was more frequent than bile reflux.

Chevallier noted that biliopancreatic limb length can impact outcomes and Bertrand et al (150-cm Versus 200-cm Biliopancreatic Limb One-Anastomosis Gastric Bypass: Propensity Score-Matched Analysis. Obes Surg. 2022 Sep;32(9):2839- 2845) patients with a BPL of 150 cm had significantly lower rates for marginal ulcers, hypoalbuminemia and reoperation.

The Hamburg 2019 Consensus Conference already showed that, for 86 % of the experts there is no evidence to suggest OAGB can cause cancer. He cited two animal studies that showed OAGB rats had not developed any pre-cancerous or cancerous lesions (Bruzzi et al Long-Term Evaluation of Biliary Reflux After Experimental One-Anastomosis Gastric Bypass in Rats. Obes Surg. 2017 Apr;27(4):1119-1122 and M'Harzi et al. Long-Term Evaluation of Biliary Reflux on Esogastric Mucosae after One-Anastomosis Gastric Bypass and Esojejunostomy in Rats. Obes Surg. 2020 Jul;30(7):2598-2605).

Chevallier concluded that OAGB results in good weight loss and bile reflux does not seem to be a major issue but a regular endoscopic survey is recommended. Furthermore, experimental studies in rats do not show a carcinogenic risk. Surgeons should be cautious using a BP Limb >150 cm with OAGB as it is associated with a definite serious malnutrition rate.

Laparoscopic Adjustable Gastric Banding (LAGB)

In his presentation assessing laparoscopic adjustable gastric banding (LAGB), Dr Jaime Ponce (CHI Memorial Hospital, Chattanooga, TN) said the efficacy of the procedure, in terms of weight loss and obesity complications, has a high level of evidence (RCTs). Two obesity management guidelines (Jensen et al. Circulation. 2014;129[suppl 2]:S102-S138 and Mechanick et al. Surg Obes Relat Dis 2020:16 ;175–247) noted that the favourable aspects of the procedure include no anatomic alteration, the band is removable and adjustable. However, LAGB has high explant, erosion and slip/ prolapse rates.

The evidence suggests that perioperative complications (<30-days) are infrequent and do not tend to be life-threatening (level of evidence 2/3, strength: moderate), although longer-term complications continue to occur over time and may require operative correction (level of evidence 2/3, strength: moderate). Longer-term failure (inadequate weight loss most common) leading to removal w/ or without conversion to another bariatric procedure is 2-34% (level of evidence 2/3, strength: moderate).

Randomised controlled trials have also highlighted this problem and Ponce cited three trials with follow-up at ten years that reported band removal rates of 12% (O'Brien et al. Intensive medical weight loss or laparoscopic adjustable gastric banding in the treatment of mild to moderate obesity: long-term follow-up of a prospective randomised trial. Obes Surg. 2013 Sep;23(9):1345-53), 31% (Nguyen NT, Kim E, Vu S, Phelan M. Ten-year Outcomes of a Prospective Randomized Trial of Laparoscopic Gastric Bypass Versus Laparoscopic Gastric Banding. Ann Surg. 2018 Jul;268(1):106-113) and 41% (Angrisani et al. Laparoscopic adjustable gastric banding versus Roux-en-Y gastric bypass: 10-year results of a prospective, randomized trial. Surg Obes Relat Dis. 2013 May-Jun;9(3):405-13).

He concluded that LAGB now accounts for just 1% of MBS and despite that it can result in 20-25% TBWL (level 1 data), the technique requires long-term adjustments and has a high reoperation and band removal rate (up to 60%) However, he said LAGB is still an accepted MBS-option for selected patients by experienced surgeons/team.

One anastomosis duodenal switch like procedure – long-term results

Dr Andrés Sánchez-Pernaute (Hospital Clínico San Carlos, Madrid, Spain) explained there are two ongoing prospective randomised trials assessing one anastomosis duodenal switch (DS)- like procedures sleeve gastrectomy with single anastomosis duodenoileostomy (SADI-S), although no results have been published so far. There are more than 120 articles in the literature and five systematic reviews focusing on safety/ weight loss/comorbidities/quality of life/ late complications.

The evidence suggests that the procedure has a shorter operative time than the duodenal switch and a low rate of postoperative complications. The incidence of complications associated with loop duodenoileostomy after single-anastomosis duodenal switch procedures among 1328 patients: a multicenter experience. Surg Obes Relat Dis. 2018 May;14(5):594-601), as a possible alternative treatment option to BPD-DS in managing patients with obesity (Nakanishi et al. Single Versus Double Anastomosis Duodenal Switch in the Management of Obesity: A Meta-analysis and Systematic Review. Surg Laparosc Endosc Percutan Tech. 2022 Oct 1;32(5):595-605) and low rates of long-term bile reflux in a meta-analysis (Portela et al. Bile Reflux After Single Anastomosis Duodenal-Ileal Bypass with Sleeve (SADI-S): a Meta-analysis of 2,029 Patients. Obes Surg. 2022 May;32(5):1516- 1522).

Jacques Himpens

However, in comparison to RYGB, patients undergoing SADI-S were found to have more metabolic comorbidities, worse perioperative outcomes and is independently associated with serious complications (Verhoeff et al. Patient Selection and 30-Day Outcomes of SADI-S Compared to RYGB: a Retrospective Cohort Study of 47,375 Patients. Obesity Surgery 32, 1–8 (2022)).

Regarding long-term weight loss, Sánchez-Pernaute said the procedure has EWL and TWL of 87% and 38% at 5 years and 80% and 34% at ten years (Sánchez-Pernaute A, Herrera MÁR, Ferré NP, Rodríguez CS, Marcuello C, Pañella C, Antoñanzas LL, Torres A, Pérez-Aguirre E. Long-Term Results of Single-Anastomosis Duodeno-ileal Bypass with Sleeve Gastrectomy (SADI-S). Obes Surg. 2022 Mar;32(3):682-689). Furthermore, in comparison to RYGB, Surve et al. (A Matched Cohort Comparison of Longterm Outcomes of Roux-en-Y Gastric Bypass (RYGB) Versus Single-Anastomosis Duodeno-ileostomy with Sleeve Gastrectomy (SADI-S). OBES SURG 31, 1438–1448 (2021)) reported weight loss was significantly greater in the SADI-S group at five years and the long-term weight-loss failure rate was significantly higher in the RYGB group. The SADI-S procedure was associated with fewer reintervention through six years (14.7% patients vs. 39.3% patients, p=0.001) and conversion or reversal of the procedure was required only in the RYGB group. However, in a comparison between SADI-S and BPS-DS, Pujol et al. (Duodenal Switch vs. Single Anastomosis Duodenal Switch (SADI-S) for the Treatment of Grade IV Obesity: five-year Outcomes of a Multicenter Prospective Cohort Comparative Study. Obes Surg. 2022 Dec;32(12):3839-3846) found BPS-DS had better % EWL 80.5% vs. 68.6% (p=0.006) at five years. Regarding comorbidities, metabolic and nutritional outcomes, Verhoeff et al (Evaluation of Metabolic Outcomes Following SADI-S: a Systematic Review and Meta-analysis. Obes Surg. 2022 Apr;32(4):1049-1063) reported DM remission was 87%, hypertension 63% and fewer malabsorptive complications than RYGB.

As second step procedure (SADI-S after SG), Balibrea et al (Mid-Term Results and Responsiveness Predictors After Two-Step Single-Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy. Obes Surg. 2017 May;27(5):1302-1308), found a second-step strategy in patients with severe obesity or after failed SG offers a more than satisfactory ponderal weight loss and an acceptable comorbidities resolution. Compared to OAGB-MGB, Bashah et al (Single Anastomosis Duodeno-ileostomy (SADI-S) Versus One Anastomosis Gastric Bypass (OAGB-MGB) as Revisional Procedures for Patients with Weight Recidivism After Sleeve Gastrectomy: a Comparative Analysis of Efficacy and Outcomes. Obes Surg. 2020 Dec;30(12):4715-4723) SADI-S and OAGBMGB were effective and safe revisional procedures for RWG after LSG. However, SADI-S is associated with less upper gastrointestinal complications and could be a better option for patients suffering from GERD post-LSG.

Finally, Dijkhorst et al (Single Anastomosis Duodenoileal Bypass or Roux-en-Y Gastric Bypass After Failed Sleeve Gastrectomy: MediumTerm Outcomes. Obes Surg. 2021 Nov;31(11):4708-4716), reported the conversion of SG to SADI-S leads to significantly more total weight loss compared to RYGB surgery with no difference in the quality of life scores, complication rates, or micronutrient deficiencies.

Sánchez-Pernaute said the procedure is comparable to BPS-DS and has better results than RYGB. The procedure is also safe, but he said non-experienced surgical teams should approach the procedure with caution. He advised a limb length of ≥250 cm for long-term follow-up and supplementation. He concluded SADI-S is a good option as a second step, but there are a low number of studies.

Algorithm to choose the best operation

Next, Professor Jacques Himpens (Delta Chirec Hospital, Brussels, Belgium) examined the evidence for each procedure and discussed a possible algorithm (Figure 1) to choose the best operation. He began by stating that preoperative endoscopy is a must for safe MBS (level 1: Wang et al. Obes Surg. 2021 Jan;31(1):337-342) to determine the presence of severe gastric disease, Esophagitis and Barrett’s esophagus even in asymptomatic patients (level 1: Qumseya et al. Obes Surg 2022;32(11):3513-22).

Figure 1: Hiatal hernia repair: HHR. HH: hiatal hernia OAGB: One anastomosis gastric bypass; RYGB: Roux en Y g.bypass T2DM: case by case SG vs RYGB (Aminian) vs OAGB (Robert) BMI>50: staged DS/(SADI) level 3b lannelli et al. SOARD 2013; 9(4):531- 8 Age>60: efficacy lower; morbidity and complications higher* (LSG>RYGB) Level 1 Metanalysis* Vallois A et al Obes Surg 2020;30:5059-70 Level 1 Metanalysis Giordano S et al. Laparoendosc Adv Surg Tech A 2020;30(1):12-19

Furthermore, the presence of Helicobacter Pylori (HP) must be checked before any MBS procedure that includes gastric exclusion because HP may facilitate the appearance of gastric carcinoma, atrophy, ulceration or gastrointestinal stromal tumour (GIST) (level 1: Wang et al. Obes Surg 2021;31(1):337-42). If HP is identified, it should be eradicated before MBS because eradication reduces the risk of carcinoma of the stomach (level 1: Lee et al. Gastroenterology 2016;150(5):1113- 24). However, HP does protect against esophageal adenocarcinoma (level 1:Xie et al. World J Gastroenterol 2013;19(36):6098- 6107).

He said the prevalence of Barrett’s esophagus after SG is high and increases year by year and there is no evidence that this happens after RYGB (level 1:Qumseya et al. Gastrointest Endosc 2021;93(2):343-52). Hiatal hernia repair (HHR) concomitant with SG has more complications than RYGB (level 3: Lewis et al. SOARD 2021;17(1):72-80) and (with one-year follow-up) no clear benefit over SG without HHR (level 1: Snyder et al. SOARD 2016;12(9):1681-8). However, HHR concomitant with SG seems to improve esophagitis and GERD (level 1: Chen et al. Obes Surg 2021;31(9)3905-18).

Concerning OAGB versus RYGB in terms of GERD remission, there is no difference (at six months) (level 1:Li et al. Obes Surg 2023;33(2):611-22). The outcomes of SG and RYGB are comparable in terms of weight loss and diabetes control (level 1: Salminen et al. JAMA Surg 2022;157(8):656- 66). However, the SLEEVEPASS trial also revealed the prevalence of esophagitis, but not Barrett’s, is higher after SG (SG 30.7% vs. LRYGB 7.1%, p<0.001). OAGB is not inferior to RYGB in terms of weight loss and glucose control (level 1: Robert et al. Lancet 2019;393(10178):1299-1309). Finally, BPD-DS/BPD have excellent clinical results but the prevalence of complications make these procedures less attractive (level 3: Clapp et al. SOARD (2022);18(2):253-59).

Revisional surgery after RYGB

In his second presentation, Professor Himpens said Roux-en-Y gastric bypass (RYGB) is still one of the most frequently performed metabolic-bariatric surgery (MBS) procedures. It is hardly surprising that revisional surgery is often required to correct outcomes (such as suboptimal weight loss, excessive weight loss or weight regain after initial satisfactory weight loss), or to adjust aberrations that were caused either at the time of surgery or that developed with time and that interfere with correct physiology of RYGB, resulting in marginal ulcer, dumping syndrome, gastro-esophageal reflux disease (GERD), persistent or recurrent pain, meteorism, flatulence and diarrhea. Perhaps the most difficult aspect of revisional surgery after RYGB is actually IF and WHEN one should intervene surgically (Mauro MFFP, Papelbaum M, Brasil MAA, Carneiro JRI, Coutinho ESF, Coutinho W, Appolinario JC. Is weight regain after bariatric surgery associated with psychiatric comorbidity? A systematic review and meta-analysis. Obes Rev. 2019 Oct;20(10):1413-1425). Actually, Most undesired outcomes can be adequately treated by non-surgical means (dietary, genetic, psychiatric) (Athanasiadis DI, Martin A, Kapsampelis P, Monfared S, Stefanidis D. F

actors associated with weight regain post-bariatric surgery: a systematic review. Surg Endosc. 2021 Aug;35(8):4069-4084).

When the primary goal is to correct weight issues, several options are possible, none of which has demonstrated clear superiority (Kermansaravi M, Davanpanah Jarzi A, Shahmiri S, Eghbali F, Valiz R. Revision procedure after initial Roux-en-Y gastric bypass, treatment of weight regain: a systematic review and meta-analysis. Updates in Surgery 2021;73:663-78). Possible techniques include: distal Roux-en-Y gastric bypass (DRGB), conversion to duodenal switch with one anastomosis SADI-S or two anastomosis BPD-DS, and resizing gastric pouch and /or gastrojejunal anastomosis size by laparoscopic or endoscopic techniques. However, based on the findings in this systematic review, it seems that malabsorption-enhancing procedures such DRGB or the duodenal switch with one anastomosis (SADI-S) or two anastomosis (BPD-DS) is the most effective procedure in the long-term follow-up outcome (see Figure 1: Forest plot as shown in Kermansaravi et al. meta-analysis).

Despite the Kermansaravi meta analysis, according to Mahawar et al. however, intervening on the gastric pouch and/or the size of the gastro-enterostomy do not play a significant role in terms of enhanced or impaired weight loss (Mahawar K, Sharples A, Graham Y. A systematic review of the effect of gastric pouch and/or gastrojejunostomy (stoma) size on weight loss outcome with Roux-en-Y gastric bypass. Surgical Endosc 2020;34:1048-60). While none of the studies analyzed by these authors showed better outcomes with larger pouches or wider gastro-jejunostomies, 9 out of 14 and 6 out of 10 did not find an influence on weight loss for larger pouches and wider stomas, respectively. According to a recent meta-analysis (Hosam A, Ali M, Elmahdy Y. Types, Safety, and Efficacy of Limb Distalization for Inadequate Weight Loss After Roux-en-Y Gastric Bypass: A Systematic Review and Meta-analysis With a Call for Standardized Terminology. Annals of Surgery 2021), inadequate weight loss after RYGB is best approached by lengthening the biliopancreatic limb at the expense of the common limb, i.e. by distalizing the bypass, while preserving a safety margin so that alimentary limb length + common limb length remain longer than 350 cm. (Figure 2). Further shortening the limbs was not associated with better %EWL (P=0.9), but it was significantly associated with severe protein malnutrition (P=0.01).

Figure 2: Graphic representation of the three elements (“limbs”) of a Roux-en-Y construction. The technique shown represents lengthening the biliopancreatic limb at the expense of the common limb, i.e. distalizing the bypass, while preserving a safety margin so that alimentary limb length + common limb length remain longer than 350 cm.

As mentioned before, SADI-S or DS are viable options when weight loss is estimated suboptimal after RYGB. However, in a recent expert consensus attempt, applicability of BPD/DS is limited by technical difficulty; 86.2% of experts would routinely recommend or consider the procedure if it were more technically feasible after failed bypass (Merz A, Blackstone R, Gagner M, Torres A, Himpens J, Higa K, Rosenthal R, Lloyd A, DeMaria E. Duodenal switch in revisional bariatric surgery: conclusions from an expert consensus panel. SOARD 2019;15:894-9).

When the multidisciplinary advisory team decides to select surgery as an option for non-weight related issues after RYGB, mostly for dumping syndrome or GERD, ad hoc treatment must be chosen because evidence-based treatment modes are widely lacking. Ligamentum teres hepatis to reinforce hiatal hernia repair, radiofrequency abrasion of the distal esophagus and use of the upper part of the remnant to create a sling at the gastro-esophageal junction have been described in the context of postRYGB GERD, whereas endoscopic or laparoscopic trimming of the gastrojejunal anastomosis or even placement of a loose non-adjustable band distally around the gastric pouch may cause slowing of gastric pouch emptying, hence improve the dumping syndrome.

Pouch volume and gastro-jejunal anastomotic size are “probably” not all that important. Limb lengths may be altered to improve weight loss but one should beware of malnutrition. Total alimentary limb length is the most important factor in terms of avoiding protein malnutrition. Dumping as well as GERD can be an issue after RYGB but treatment options based on scientific evidence are missing, he concluded.


bottom of page