30-day morbidity and mortality of revisional bariatric surgery - An international multi-centre collaborative (BROAD) study.

INTRODUCTION: Revisional bariatric surgery (RBS) for insufficient weight loss/weight regain or metabolic relapse is increasing worldwide. There is currently no large multinational, prospective data on 30-day morbidity and mortality of RBS. In this study, we aimed to evaluate the 30-day morbidity and mortality of RBS at participating centres. METHODS: An international steering group was formed to oversee the study. The steering group members invited bariatric surgeons worldwide to participate in this study. Ethical approval was obtained at the lead centre. Data were collected prospectively on all consecutive RBS patients operated between 15th May 2021 to 31st December 2021. Revisions for complications were excluded. RESULTS: A total of 65 global centres submitted data on 750 patients. Sleeve gastrectomy (n = 369, 49.2 %) was the most common primary surgery for which revision was performed. Revisional procedures performed included Roux-en-Y gastric bypass (RYGB) in 41.1 % (n = 308) patients, One anastomosis gastric bypass (OAGB) in 19.3 % (n = 145), Sleeve Gastrectomy (SG) in 16.7 % (n = 125) and other procedures in 22.9 % (n = 172) patients. Indications for revision included weight regain in 615(81.8 %) patients, inadequate weight loss in 127(16.9 %), inadequate diabetes control in 47(6.3 %) and diabetes relapse in 27(3.6 %). 30-day complications were seen in 80(10.7 %) patients. Forty-nine (6.5 %) complications were Clavien Dindo grade 3 or higher. Two patients (0.3 %) died within 30 days of RBS. CONCLUSION: RBS for insufficient weight loss/weight regain or metabolic relapse is associated with 10.7 % morbidity and 0.3 % mortality. Sleeve gastrectomy is the most common primary procedure to undergo revisional bariatric surgery, while Roux-en-Y gastric bypass is the most commonly performed revision.

Analysis of the effect of staple line reinforcement on leaking and bleeding after sleeve gastrectomy from the UK National Bariatric Surgery Registry.

INTRODUCTION: Sleeve gastrectomy (SG) is currently the most frequently performed procedure for obesity worldwide. Staple line reinforcement (SLR) has been suggested as a strategy to reduce the risk of staple line leak or bleeding; however, its use for SG in the United Kingdom (UK) is unknown. This study examined the effect of SLR on the development of postoperative complications from SG using a large national dataset from the UK. METHODS: Patients undergoing either primary or revision SG over 10 years from Jan 2012 to Dec 2021 were identified by the National Bariatric Surgery Registry. Comparative and logistic regression analyses were undertaken to determine the effect of SLR on staple line leak and bleeding. RESULTS: During this time, 14,231 patients underwent SG for whom there were complete data. Of these, 76.5% were female and the median age was 46 years (IQR: 36-53). The rate of surgical complications was 2.3% (n = 219/14,231). The incidence of bleeding was 1.3% (n = 179/14,231) and leak was 1.0% (n = 140/14,231). Over time, the use of SLR of any variety declined significantly from 99.7% in 2012 to 57.3% in 2021 (p < 0.001). Multivariable (adjusted) regression analysis demonstrated that neither the use of nor the type of reinforcement had any effect on the rate of bleeding or leaking. CONCLUSION: SLR for SG has declined in the UK since 2012. There were no differences in staple line leak or bleed with or without reinforcement.

The role of metabolic and bariatric surgery on the obesity pandemic in Latin America: A review of current practices and future directions.

Latin America faces a significant public health challenge due to the high prevalence of obesity and its associated diseases. Metabolic and bariatric surgery is effective and safe to treat obesity when other treatments fail; however, its implementation in Latin America remains unsatisfactory. This review explores the current status, challenges, and innovations of metabolic and bariatric surgery in Latin America. We searched peer-reviewed journals in English and Spanish for relevant articles published between 1998 and 2023. We found that more than 20% of the Latin American population is affected by obesity. Unfortunately, only a limited number of patients have access to metabolic and bariatric surgery due to high cost, limited availability, and shortage of specialists. The review found that ongoing clinical trials are being conducted in Brazil, Mexico, Chile, and Venezuela, indicating some regional progress. However, published studies remain low in number compared with other regions. Furthermore, we summarized the clinical outcomes, risks, and perioperative assessments associated with metabolic and bariatric surgery. We discussed potential strategies to enhance the availability and affordability of this intervention. This review emphasizes the significance of metabolic and bariatric surgery in addressing the obesity pandemic, specifically for Latin America, and proposes directions for future research and innovation.

Recompensation in MASLD-related cirrhosis via metabolic bariatric surgery.

The prognosis of patients with decompensated cirrhosis is poor, with significantly increased liver-related mortality rates. With the rising tide of decompensated cirrhosis associated with metabolic dysfunction-associated steatotic liver disease (MASLD), the role of metabolic bariatric surgery (MBS) in achieving hepatic recompensation is garnering increasing attention. However, the complexity of preoperative assessment, the risk of postoperative disease recurrence, and the potential for patients to experience surgical complications of the MBS present challenges. In this opinion article we analyze the potential of MBS to induce recompensation in MASLD-related cirrhosis, discuss the mechanisms by which MBS may affect recompensation, and compare the characteristics of different MBS procedures; we highlight the therapeutic potential of MBS in MASLD-related cirrhosis recompensation and advocate for research in this complex area.

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.

Current recommendations for procedure selection in class I and II obesity developed by an expert modified Delphi consensus.

Metabolic and bariatric surgery (MBS) is widely considered the most effective option for treating obesity, a chronic, relapsing, and progressive disease. Recently, the American Society of Metabolic and Bariatric Surgery (ASMBS) and the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) issued new guidelines on the indications for MBS, which have superseded the previous 1991 National Institutes of Health guidelines. The aim of this study is to establish the first set of consensus guidelines for selecting procedures in Class I and II obesity, using an Expert Modified Delphi Method. In this study, 78 experienced bariatric surgeons from 32 countries participated in a two-round Modified Delphi consensus voting process. The threshold for consensus was set at an agreement or disagreement of ≥ 70.0% among the experts. The experts reached a consensus on 54 statements. The committee of experts reached a consensus that MBS is a cost-effective treatment option for Class II obesity and for patients with Class I obesity who have not achieved significant weight loss through non-surgical methods. MBS was also considered suitable for patients with Type 2 diabetes mellitus (T2DM) and a body mass index (BMI) of 30 kg/m2 or higher. The committee identified intra-gastric balloon (IGB) as a treatment option for patients with class I obesity and endoscopic sleeve gastroplasty (ESG) as an option for patients with class I and II obesity, as well as for patients with T2DM and a BMI of ≥ 30 kg/m2. Sleeve gastrectomy (1) and Roux-en-Y gastric bypass (RYGB) were also recognized as viable treatment options for these patient groups. The committee also agreed that one anastomosis gastric bypass (OAGB) is a suitable option for patients with Class II obesity and T2DM, regardless of the presence or severity of obesity-related medical problems. The recommendations for selecting procedures in Class I and II obesity, developed through an Expert Modified Delphi Consensus, suggest that the use of standard primary bariatric endoscopic (IGB, ESG) and surgical procedures (SG, RYGB, OAGB) are acceptable in these patient groups, as consensus was reached regarding these procedures. However, randomized controlled trials are still needed in Class I and II Obesity to identify the best treatment approach for these patients in the future.

Safety outcomes of bariatric surgery in patients with advanced organ disease: the ONWARD study: a prospective cohort study.

INTRODUCTION: Increasing numbers of patients with advanced organ disease are being considered for bariatric and metabolic surgery (BMS). There is no prospective study on the safety of BMS in these patients. This study aimed to capture outcomes for patients with advanced cardiac, renal, or liver disease undergoing BMS. MATERIALS AND METHODS: This was a multinational, prospective cohort study on the safety of elective BMS in adults (≥18 years) with advanced disease of the heart, liver, or kidney. RESULTS: Data on 177 patients with advanced diseases of heart, liver, or kidney were submitted by 75 centres in 33 countries. Mean age and BMI was 48.56±11.23 years and 45.55±7.35 kg/m 2 , respectively. Laparoscopic sleeve gastrectomy was performed in 124 patients (70%). The 30-day morbidity and mortality were 15.9% ( n =28) and 1.1% ( n =2), respectively. Thirty-day morbidity was 16.4%, 11.7%, 20.5%, and 50.0% in patients with advanced heart ( n =11/61), liver ( n =8/68), kidney ( n =9/44), and multi-organ disease ( n =2/4), respectively. Cardiac patients with left ventricular ejection fraction less than or equal to 35% and New York Heart Association classification 3 or 4, liver patients with model for end-stage liver disease score greater than or equal to 12, and patients with advanced renal disease not on dialysis were at increased risk of complications. Comparison with a propensity score-matched cohort found advanced disease of the heart, liver, or kidney to be significantly associated with higher 30-day morbidity. CONCLUSION: Patients with advanced organ disease are at increased risk of 30-day morbidity following BMS. This prospective study quantifies that risk and identifies patients at the highest risk.

Malnutrition Following One-Anastomosis Gastric Bypass: a Systematic Review.

Severe malnutrition following one-anastomosis gastric bypass (OAGB) remains a concern. Fifty studies involving 49,991 patients were included in this review. In-hospital treatment for severe malnutrition was needed for 0.9% (n = 446) of patients. Biliopancreatic limb (BPL) length was 150 cm in five (1.1%) patients, > 150 cm in 151 (33.9%), and not reported in 290 (65%) patients. OAGB was revised to normal anatomy in 126 (28.2%), sleeve gastrectomy in 46 (10.3%), Roux-en-Y gastric bypass in 41 (9.2%), and shortening of BPL length in 17 (3.8%) patients. One hundred fifty-one (33.8%) patients responded to treatment; ten (2.2%) did not respond and was not reported in 285 (63.9%) patients. Eight (0.02%) deaths were reported. Standardisation of the OAGB technique along with robust prospective data collection is required to understand this serious problem.

Bariatric Evaluation Through AI: a Survey of Expert Opinions Versus ChatGPT-4 (BETA-SEOV).

BACKGROUND: Recent advancements in artificial intelligence, such as OpenAI's ChatGPT-4, are revolutionizing various sectors, including healthcare. This study investigates the use of ChatGPT-4 in identifying suitable candidates for bariatric surgery and providing surgical recommendations to improve decision-making in obesity treatment amid the global obesity epidemic. METHODS: We devised ten patient scenarios, thoughtfully encompassing a spectrum that spans from uncomplicated cases to more complex ones. Our objective was to delve into the decision-making process regarding the recommendation of bariatric surgery. From July 29th to August 10th, 2023, we conducted a voluntary online survey involving thirty prominent bariatric surgeons, ensuring that there was no predetermined bias in the selection of a specific type of bariatric surgery. This survey was designed to collect their insights on these scenarios and gain a deeper understanding of their professional experience and background in the field of bariatric surgery. Additionally, we consulted ChatGPT-4 in two separate conversations to evaluate its alignment with expert opinions on bariatric surgery options. RESULTS: In 40% of the scenarios, disparities were identified between the two conversations with ChatGPT-4. It matched expert opinions in 30% of cases. Differences were noted in cases like gastrointestinal metaplasia and gastric adenocarcinoma, but there was alignment with conditions like endometriosis and GERD. CONCLUSION: The evaluation of ChatGPT-4's role in determining bariatric surgery suitability uncovered both potential and shortcomings. Its alignment with experts was inconsistent, and it often overlooked key factors, emphasizing human expertise's value. Its current use requires caution, and further refinement is needed for clinical application.

Marginal Ulcers Following One-Anastomosis Gastric Bypass: a Systematic Review and Meta-analysis.

BACKGROUND: Marginal ulcer (MU) is an uncommon but significant complication following one-anastomosis gastric bypass (OAGB). Our study aims to understand the incidence rates, risk factors, and management of MU following OAGB. METHODS: MEDLINE, Scopus, and Cochrane Library databases were examined to identify all studies on OAGB where authors had reported on MU. Data were collected on basic demographics, incidence rates, risk factors, and management of this condition. RESULTS: Thirty-two studies involving 8868 patients were analysed. The mean age and body mass index (BMI) of patients in these studies were 40.9 ± 4.5 years and 47.6 ± 5.6 kg/m2, respectively. Among the patient cohort, approximately 72% were female, and 20.6% had preoperative gastroesophageal reflux disease (GERD). The authors described prescribing proton-pump inhibitors (PPI) prophylaxis to 14.1% of patients after surgery. Two hundred twenty-eight patients were reported to have MU. The incidence of MU was 2.59% (95% CI 1.89-3.52), of which 53 patients presented within 12 months, 24 patients presented after 31 months, and five patients after 6 years. One hundred forty-six patients did not have presentation time documented. Sixty-five patients were described to have MU diagnosed on endoscopy, of which 54 were symptomatic and 11 were asymptomatic. The authors were, however, not specific on the choice of investigation for the remaining 163 patients. Of patients, 89.7% were treated conservatively with PPIs, whilst 10.3% had surgery to treat MU. CONCLUSIONS: Marginal ulcer is an uncommon complication following OAGB. The majority of patients are treated conservatively with PPIs. Larger, well-designed studies reporting on risk factors, investigation, and management of MU following OAGB are warranted.

Developing a long-term follow up service for bariatric surgical patients in the community: Patient and professional perspectives.

Background: In the UK, bariatric surgical patients are followed up for 2 years post-operatively in hospital settings, before being discharged into General Practice for long-term follow-up. Presently, there is ambiguous guidance as to what should be included in a community-based bariatric surgical follow-up service. The aim of the study was to understand, from both patient and professional perspectives, what is needed to support the long-term management of bariatric surgical patients in community-based settings. Methods: Post-surgical bariatric patients and General Practice staff were recruited from an area in the UK which has an National Health Service (NHS) hospital providing a high-volume and established bariatric surgical service. Data was collected through semi-structured interviews. A thematic analytic framework was used to construct eight themes which illuminated the participants' experiences. The study took place between March and December 2021. Findings: Thirty participants (14 patients and 16 healthcare professionals) were recruited to the study. The study revealed the lack of a framework for delivery of a long-term follow up service was frustrating to both patients and professionals. Patient participants reported needing more support, especially dietetic and psychological input, and professionals stated they had little knowledge about bariatric surgical care, and what was needed to provide optimal care, but wanted to provide quality patient care. Conclusion: Long-term follow up of bariatric surgical patients is an important issue which needs addressing. This study illuminates both the patient and professional perspectives on developing a pragmatic, community-based service which meets the needs of patients and considers the need to incorporate such a service into existing infrastructures without adding additional demands on General Practice.

Bariatric surgeons' experiences of working in the first year of the pandemic.

Background: The first year of the Covid-19 pandemic saw drastic changes to bariatric surgical practice, including postponement of procedures, altered patient care and impacting on the role of bariatric surgeons. The consequences of this both personally and professionally amongst bariatric surgeons has not as yet been explored. Aims: The aim of this research was to understand bariatric surgeons' perspectives of working during the first year of the pandemic to explore the self-reported personal and professional impact. Methods: Using a retrospective, two phased, study design with global participants recruited from closed, bariatric surgical units. The first phase used a qualitative thematic analytic framework to identify salient areas of importance to surgeons. Themes informed the construction of an on-line, confidential survey to test the potential generalizability of the interview findings with a larger representative population from the global bariatric surgical community. Findings: Findings of the study revealed that the first year of the pandemic had a detrimental effect on bariatric surgeons both personally and professionally globally. Conclusion: This study has identified the need to build resilience of bariatric surgeons so that the practice of self-care and the encouragement of help-seeking behaviors can potentially be normalized, which will in turn increase levels of mental health and wellbeing.

Bariatric surgery provision in response to the COVID-19 pandemic: retrospective cohort study of a national registry.

BACKGROUND: When surgery resumed following the outbreak of the COVID-19 pandemic, guidelines recommended the prioritization of patients with greater obesity-related co-morbidities and/or higher body mass index. OBJECTIVE: The aim of this study was to record the effect of the pandemic on total number, patient demographics, and perioperative outcomes of elective bariatric surgery patients in the United Kingdom. SETTING AND METHODS: The United Kingdom National Bariatric Surgical Registry was used to identify patients who underwent elective bariatric surgery during the pandemic (1 yr from April 1, 2020). Characteristics of this group were compared with those of a pre-pandemic cohort. Primary outcomes were case volume, case mix, and providers. National Health Service cases were analyzed for baseline health status and perioperative outcomes. Fisher exact, χ2, and Student t tests were used as appropriate. RESULTS: The total number of cases decreased to one third of pre-pandemic volume (8615 to 2930). The decrease in operating volume varied, with 36 hospitals (45%) experiencing a 75%-100% reduction. Cases performed in the National Health Service fell from 74% to 53% (P < .0001). There was no change in baseline body mass index (45.2 ± 8.3 kg/m2 from 45.5 ± 8.3 kg/m2; P = .23) or prevalence of type 2 diabetes (26% from 26%; P = .99). Length of stay (median 2 d) and surgical complication rate (1.4% from 2.0%; relative risk = .71; 95% CI .45-1.12; P = .13) were unchanged. CONCLUSIONS: In the context of a dramatic reduction in elective bariatric surgery due to the COVID-19 pandemic, patients with more severe co-morbidities were not prioritized for surgery. These findings should inform preparation for future crises.

Global trends in BMS research using publication as a surrogate marker: A 30 year review.

Obesity is a global pandemic with increasing prevalence and long-term negative health outcomes. Bariatric metabolic surgery (BMS) is the most effective treatment option for achieving long-term weight loss. A systematic search was performed from 1990 to 2020 of BMS procedures using standardised groups. Data were collected on operation type reported, country and continent of publication. North America and Europe were the leading contributors to global publications in BMS, producing 41.3 % (n = 4931) and 37.1 % (n = 4436) of publications respectively, with increasing publications from Asia. Roux-en-Y Gastric Bypass (RYGB) and Sleeve Gastrectomy (SG) were the most studied procedure types with number of publications continuing to increase over time. A plateau and downward trend was seen for Laparoscopic Adjustable Gastric Band (LAGB) publication from 2015 to 2019. An increase in emerging/experimental techniques over the past decade is observed.

Gastrointestinal reported outcomes following one anastomosis gastric bypass based on a multicenter study.

OBJECTIVES: To describe gastrointestinal-related side-effects reported following the One Anastomosis Gastric Bypass (OAGB). METHODS: A multicenter study among OAGB patients across Israel (n = 277) and Portugal (n = 111) who were recruited to the study based on time elapsed since surgery was performed. An online survey with information on demographics, anthropometrics, medical conditions, and gastrointestinal outcomes was administered in both countries simultaneously. RESULTS: Respondents from Israel (pre-surgery age of 41.6 ± 11.0 years, 75.8% females) and Portugal (pre-surgery age of 45.6 ± 12.3 years, 79.3% females) presented mean excess weight loss of 51.0 ± 19.9 and 62.4 ± 26.5%, 89.0 ± 22.0 and 86.2 ± 21.4%, and 89.9 ± 23.6 and 98.2 ± 20.9% (P < 0.001 for both countries), at 1-6 months, 6-12 months, and 1-5 years post-surgery, respectively. Median Gastrointestinal Symptom Rating Scale score was similar between time elapsed since surgery groups among respondents from Israel and Portugal (≤1.97 and ≤2.12). A notable proportion of respondents from Israel and Portugal at all time points reported 1-3 bowel movements per day (≤62.8 and ≤87.6%), Bristol stool scale categories which represent diarrhea-like stools (≤51.9 and ≤56.3%), having discomfort due to flatulence (≤79.4 and ≤90.2%), and mild to severe dyspepsia symptoms (≤50.5 and ≤73.0%). CONCLUSIONS: A notable proportion of OAGB patients might experience certain gastrointestinal symptoms postoperatively, including flatulence, dyspepsia, and diarrhea-like stools.

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

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

The First Modified Delphi Consensus-Building Exercise on Surgical Ward Rounds in the United Kingdom National Health Service.

BACKGROUND: The ward round is an integral part of everyday surgical practice. It is a complex clinical activity that requires both sound clinical management and communication skills. This study reports the results of a consensus-building exercise on the common aspects of the general surgical ward rounds. METHODS: The consensus-building committee involving a range of stakeholders from 16 United Kingdom (UK) National Health Service trusts took part in this consensus exercise. The members discussed and suggested a series of statements concerning surgical ward round. An agreement of ≥ 70% among members was regarded as a consensus. RESULTS: Thirty-two members voted on 60 statements. There was a consensus on fifty-nine statements after the first round of voting, and one statement was modified before it reached consensus in the second round. The statements covered nine sections: a preparation phase, team allocation, multidisciplinary approach to the ward round, structure of the round, teaching considerations, confidentiality and privacy, documentation, post-round arrangements, and weekend round. There was a consensus on spending time to prepare for the round, a consultant-led round, involvement of the nursing staff, an MDT round at the beginning and end of the week, a minimum of 5 min allocated to each patient, utilisation of a round checklist, afternoon virtual round, and a clear handover and plan for the weekend. CONCLUSION: The consensus committee achieved agreement on several aspects concerning the surgical ward rounds in the UK NHS. This should help improve the care of surgical patients in the UK.

Clinical characteristics of patients undergoing primary bariatric surgery in the United Kingdom based on the National Bariatric Surgery Registry.

Baseline demographic characteristics and operations undertaken for patients having bariatric surgery in the United Kingdom are largely unknown. This study aimed to describe the profile of patients having primary bariatric surgery in the National Health Service (NHS) or by self-pay, and associated operations performed for both pathways. The National Bariatric Surgery Registry dataset for 5 years between January 2015 and December 2019 was used. 34 580 patients underwent primary bariatric surgery, of which 75.9% were NHS patients. Mean patient age and initial body mass index were significantly higher for NHS compared to self-pay patients (mean age 45.8 ± 11.3 [SD] vs. 43.0 ± 12.0 years and initial body mass index 48.0 ± 7.9 vs. 42.9 ± 7.3 kg/m2 , p < .001). NHS patients were more likely to have obesity-related complications compared to self-pay patients: prevalence of Type 2 diabetes mellitus 27.7% versus 8.3%, hypertension 37.1% versus 20.1%, obstructive sleep apnoea 27.4% versus 8.9%, severely impaired functional status 19.3% versus 13.9%, musculoskeletal pain 32.5% versus 20.1% and being on medication for depression 31.0% versus 25.9%, respectively (all p < .001). Gastric bypass was the most commonly performed primary NHS bariatric operation 57.2%, but sleeve gastrectomy predominated in self-pay patients 48.7% (both p < .001). In contrast to self-pay patients, NHS patients are receiving bariatric surgery only once they are older and at a much more advanced stage of obesity-related disease complications.