Bariatric Surgery Is Efficacious and Improves Access to Transplantation for Morbidly Obese Renal Transplant Candidates

New Onset Diabetes After Organ Transplantation: Risk Factors, Treatment, and Consequences

New onset diabetes mellitus after organ transplantation (NODAT) is a frequent and serious complication of solid organ transplantation. It significantly impacts graft function, patient survival, and quality of life. NODAT is diagnosed based on the criteria for type 2 diabetes, with the oral glucose tolerance test (OGTT) serving as the gold standard for diagnosis. The development of NODAT is influenced by a range of risk factors, which are classified into modifiable and non-modifiable categories. Post-transplant, regular glycemic monitoring at specific intervals is essential for timely diagnosis and initiation of therapy. Early intervention can help prevent or delay the onset of diabetes-related complications. The treatment strategy for NODAT involves lifestyle modifications and pharmacological interventions. These include medications such as metformin, sulfonylureas, glinides, thiazolidinediones, DPP-4 inhibitors, GLP-1 agonists, SGLT-2 inhibitors, and insulin. Adjusting immunosuppressive therapy-either by reducing dosages or substituting drugs with lower diabetogenic potential-is a common preventative and therapeutic measure. However, this must be performed cautiously to avoid acute graft rejection, which poses a greater risk to the patient compared to NODAT itself. In addition to managing diabetes, addressing comorbidities such as hypertension and dyslipidemia is crucial, as they elevate the risk of cardiovascular events and mortality. Patients with NODAT are also prone to developing common diabetes-related complications, including diabetic nephropathy, neuropathy, retinopathy, and peripheral vascular disease. Therefore, regular follow-ups and appropriate treatment are vital to maintaining quality of life and improving long-term outcomes.

Medical and Surgical Weight Loss as a Pathway to Renal Transplant Listing

PURPOSE

Severe obesity is a barrier to listing for kidney transplantation due to concern for poor outcomes. This study aims to compare bariatric surgery with medical weight loss as a means of achieving weight loss and subsequent listing for renal transplant. We hypothesize that bariatric surgery will induce greater frequency of listing for transplant within 18 months of study initiation.

MATERIALS AND METHODS

We performed a randomized study of metabolic bariatric surgery (MBS) vs medical weight loss (MM) in patients on dialysis with a body mass index (BMI) of 40-55 kg/m2. The primary outcome was suitability for renal transplant within 18 months of initiating treatment. Secondary outcomes included weight loss, mortality, and complications.

RESULTS

Twenty patients enrolled, only 9 (5 MBS, 4 MM) received treatment. Treated groups did not differ in age, gender, or race (P ≥ .44). There was no statistically significant difference in the primary endpoint: 2 MBS (40%) and 1 MM (25%) listed for transplant ≤18 months (P = 1.00). With additional time, 100% MBS and 25% MM patients achieved listing status (P = .048); 100% of MBS and 0 MM received kidney transplants to date (P = .008). Weight, weight loss, and BMI trajectories differed between the groups (P ≤ .002). One death from COVID-19 occurred in the MM group, and 1 MBS patient had a myocardial infarction 3.75 years after baseline evaluation.

CONCLUSION

These results suggest MBS is superior to MM in achieving weight loss prior to listing for kidney transplantation. Larger studies are needed to ensure the safety profile is acceptable in patients with ESRD undergoing bariatric surgery.

Scientific Evidence for the Updated Guidelines on Indications for Metabolic and Bariatric Surgery (IFSO/ASMBS)

The 2022 American Society of Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) updated the indications for Metabolic and Bariatric Surgery (MBS), replacing the previous guidelines established by the NIH over 30 years ago. The evidence supporting these updated guidelines has been strengthened to assist metabolic and bariatric surgeons, nutritionists, and other members of multidisciplinary teams, as well as patients. This study aims to assess the level of evidence and the strength of recommendations compared to the previously published criteria.

Scientific evidence for the updated guidelines on indications for metabolic and bariatric surgery (IFSO/ASMBS)

The 2022 American Society for Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) updated the indications for metabolic and bariatric surgery (MBS), replacing the previous guidelines established by the National Institutes of Health (NIH) over 30 years ago. The evidence supporting these updated guidelines has been strengthened to assist metabolic and bariatric surgeons, nutritionists, and other members of multidisciplinary teams (MDTs), as well as patients. This study aims to assess the level of evidence and the strength of recommendations compared to the previously published criteria.

Analysis of Rejection, Infection and Surgical Outcomes in Type I Versus Type II Diabetic Recipients After Simultaneous Pancreas-Kidney Transplantation

Given the increasing frequency of simultaneous pancreas-kidney transplants performed in recipients with Type II diabetes and CKD, we sought to evaluate possible differences in the rates of allograft rejection, infection, and surgical complications in 298 Type I (T1D) versus 47 Type II (T2D) diabetic recipients of simultaneous pancreas-kidney transplants between 2006-2017. There were no significant differences in patient or graft survival. The risk of biopsy-proven rejection of both grafts was not significantly different between T2D and T1D recipients (HRpancreas = 1.04, p = 0.93; HRkidney = 0.96; p = 0.93). Rejection-free survival in both grafts were also not different between the two diabetes types (ppancreas = 0.57; pkidney = 0.41). T2D had a significantly lower incidence of de novo DSA at 1 year (21% vs. 39%, p = 0.02). There was no difference in T2D vs. T1D recipients regarding readmissions (HR = 0.77, p = 0.25), infections (HR = 0.77, p = 0.18), major surgical complications (HR = 0.89, p = 0.79) and thrombosis (HR = 0.92, p = 0.90). In conclusion, rejection, infections, and surgical complications after simultaneous pancreas-kidney transplant are not statistically significantly different in T2D compared to T1D recipients.

Elements of Weight Management Among Pre-Kidney Transplant Candidates: The Patient Perspective

Obesity and related comorbidities heighten risks for complications in kidney transplant settings. While pre-transplant patients often have access to nutrition counseling and health support, literature is limited on patients' perceptions of weight and motivation to lose weight prior to transplantation. We conducted a survey among ≥18-year-old patients on the kidney transplant waitlist at a single center. Questions addressed weight perception, motivation for weight loss, available resources, and engagement in physical activity. Medical records provided demographic and clinical data. Statistical tests analyzed quantitative data, while free-text responses were thematically grouped and described. Of 1055 patients, 291 responded and were matched with demographic data. Perceived weight changes correlated with actual changes in body mass index (BMI) (<24.9) were more receptive to weight center resources (<30 kg/m2) are most interested in weight loss resources and demonstrate motivation. Furthermore, pre-transplant nutrition counseling correlates with healthier behaviors. Integrating patients' perspectives enhances pre-transplant protocols by encouraging active involvement in health decisions.

International consensus on post-transplantation diabetes mellitus

Post-transplantation diabetes mellitus (PTDM) remains a leading complication after solid organ transplantation. Previous international PTDM consensus meetings in 2003 and 2013 provided standardized frameworks to reduce heterogeneity in diagnosis, risk stratification and management. However, the last decade has seen significant advancements in our PTDM knowledge complemented by rapidly changing treatment algorithms for management of diabetes in the general population. In view of these developments, and to ensure reduced variation in clinical practice, a 3rd international PTDM Consensus Meeting was planned and held from 6-8 May 2022 in Vienna, Austria involving global delegates with PTDM expertise to update the previous reports. This update includes opinion statements concerning optimal diagnostic tools, recognition of prediabetes (impaired fasting glucose and/or impaired glucose tolerance), new mechanistic insights, immunosuppression modification, evidence-based strategies to prevent PTDM, treatment hierarchy for incorporating novel glucose-lowering agents and suggestions for the future direction of PTDM research to address unmet needs. Due to the paucity of good quality evidence, consensus meeting participants agreed that making GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) recommendations would be flawed. Although kidney-allograft centric, we suggest that these opinion statements can be appraised by the transplantation community for implementation across different solid organ transplant cohorts. Acknowledging the paucity of published literature, this report reflects consensus expert opinion. Attaining evidence is desirable to ensure establishment of optimized care for any solid organ transplant recipient at risk of, or who develops, PTDM as we strive to improve long-term outcomes.

Bariatric surgery in patients with obesity and end-stage renal disease

BACKGROUND

Bariatric surgery has been suggested as a treatment for obesity and end-stage renal disease (ESRD). Although the number of bariatric surgeries in patients with ESRD is increasing, its safety and effectiveness in these patients are still controversial and the surgical method of choice in these patients is under debate.

OBJECTIVES

To compare the outcomes of bariatric surgery between patients with and without ESRD and to assess different methods of bariatric surgery in patients with ESRD.

SETTING

Meta-analysis.

METHODS

A comprehensive search was conducted in Web of Science and Medline (via Pubmed) until May 2022. Tow meta-analyses were performed: A) to compare bariatric surgery outcomes among patients with and without ESRD, and B) to compare outcomes of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) in patients with ESRD. Using a random-effect model, odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) were computed for surgical and weight loss outcomes.

RESULTS

Of 5895 articles, 6 studies were included in meta-analysis A and 8 studies in meta-analysis B. The risk of bias was moderate to serious among studies. Major postoperative complications (OR = 2.82; 95% CI = 1.66-4.77; P = .0001), reoperation (OR = 2.66; 95% CI = 1.99-3.56; P < .00001), readmission (OR = 2.37; 95% CI = 1.55-3.64; P < .0001), and in-hospital/90-d mortality (OR = 4.03; 95% CI = 1.80-9.03; P = .0007) were higher in patients with ESRD. Patients with ESRD also had a longer hospital stay (MD = 1.23; 95% CI = .32-2.14; P = .008). Bleeding, leakage, and total weight loss were comparable among groups. SG showed a 10% lower rate of overall complications and significantly shorter hospital stay than RYGB did. The quality of evidence was very low for the outcomes CONCLUSIONS: Bariatric surgery in patients with ESRD seems to have higher rates of major complications and perioperative mortality than in patients without ESRD, but a comparable rate of overall complications. SG has fewer postoperative complications and could be the method of choice in these patients. These findings should be interpreted cautiously in light of the moderate to high risk of bias in most included studies.

Bariatric surgery improves access to renal transplantation and is safe in renal failure as well as after transplantation: A systematic review and meta-analysis

INTRODUCTION

Effective workup and listing of end-stage renal disease (ESRD) patients for renal transplantation, often with multiple co-morbidities, poses a challenge for transplant teams. Obesity is a common co-morbidity associated with adverse outcomes in ESRD and kidney transplant (KT) recipients. Bariatric and metabolic surgery (BMS) has long been established as a safe and effective treatment for morbid obesity. In this study, the authors aimed to evaluate the strength of evidence for both the efficacy and safety of bariatric surgery in patients with ESRD or kidney transplantation.

METHODS

A literature search was performed using key terms including "transplantation", "kidney", "renal", "obesity", and "bariatric". Databases searched include MEDLINE, EMBASE and Web of Science from inception to date (April 2021). Methodological quality was assessed using the Newcastle-Ottawa tool. Selected articles were then categorised into patients awaiting waiting list acceptance, patients awaiting transplantation, patients undergoing simultaneous BMS + KT and patients undergoing BMS following a previous renal transplant. Summary effects are presented with a level of statistical significance and 95% Confidence Intervals.

RESULTS

A total of 28 articles were selected following the literature search. Fourteen studies on patients awaiting listing (n = 1903), nine on patients on the KT waiting list (n = 196), a single study on simultaneous BMS and KT and ten studies on patients undergoing BMS following KT (n = 198). Mean change in BMI for patients awaiting listing was -11.3 kg/m² (95%CI: -15.3 to -7.3, p < 0.001), mean change in BMI for patients listed for KT was -11.2 kg/m 2(95%CI: -12.9 to -9.5, p 0.001) and mean change for patients with prior KT was -11.0 kg/m² (95%CI: -7.09 to -14.9, p < 0.001). The combined mortality rate for patients who had undergone both BMS and KT was 4% (n = 15).

DISCUSSION

This review demonstrates BMS is both safe and efficacious in patients with ESRD prior to KT and in those post KT. It would enable difficult-to-list obese recipients the possibility to undergo transplantation and should be considered as part of the work up process.

2022 American Society of Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) Indications for Metabolic and Bariatric Surgery

MAJOR UPDATES TO 1991 NATIONAL INSTITUTES OF HEALTH GUIDELINES FOR BARIATRIC SURGERY: Metabolic and bariatric surgery (MBS) is recommended for individuals with a body mass index (BMI) >35 kg/m2, regardless of presence, absence, or severity of co-morbidities.MBS should be considered for individuals with metabolic disease and BMI of 30-34.9 kg/m2.BMI thresholds should be adjusted in the Asian population such that a BMI >25 kg/m2 suggests clinical obesity, and individuals with BMI >27.5 kg/m2 should be offered MBS.Long-term results of MBS consistently demonstrate safety and efficacy.Appropriately selected children and adolescents should be considered for MBS.(Surg Obes Relat Dis 2022; https://doi.org/10.1016/j.soard.2022.08.013 ) © 2022 American Society for Metabolic and Bariatric Surgery. All rights reserved.

Bariatric Surgery in Kidney Transplant Candidates and Recipients: Experience at an Asian Center

Background

Kidney transplant (KT) candidates and recipients with obesity experience more frequent complications such as infection, poorer allograft outcomes, diabetes, and mortality, limiting their eligibility for transplantation. Bariatric surgery (BS) is not commonly performed among KT patients given concerns about immunosuppression absorption, wound healing, infections, and graft outcomes. Its role has not been described before in an Asian KT patient setting.

Methods

A retrospective review of patients who underwent BS at the largest KT center in Singapore from 2008 to 2020 was conducted. Metabolic outcomes, immunosuppression doses, graft outcomes, and mortality were studied.

Results

Seven patients underwent BS and KT (4 underwent BS before KT, 3 underwent BS after KT; 4 underwent sleeve gastrectomy, 3 underwent gastric bypass). Mean total weight losses of 23.8% at 1 year and 18.6% at 5 years post-BS were achieved. Among the five patients with diabetes, glycemic control improved after BS. There were no deaths in the first 90 days or graft loss in the first year after KT and BS. Patients who underwent BS after KT had no significant changes in immunosuppression dose.

Conclusion

BS can be safely performed in KT recipients and candidates and results in sustainable weight losses and improvements in metabolic comorbidities. Although no major complications were observed in our study, close monitoring of this complex group of patients is imperative.

2022 American Society for Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO): Indications for Metabolic and Bariatric Surgery

Major updates to 1991 National Institutes of Health guidelines for bariatric surgery.

Bariatric surgery before and after kidney transplantation: a propensity score-matched analysis

BACKGROUND

Obesity is becoming more prevalent in the end-stage renal disease population. Bariatric surgery (BS) is increasingly considered as an approach to become eligible for kidney transplant (KT) or reduce obesity-related morbidities.

OBJECTIVES

To assess the short- and long-term outcomes of patients who underwent both BS and KT and to determine the optimal timing of BS.

METHODS

Patients who underwent both KT and BS between January 2000 and December 2020 were included and stratified according to the sequence of the 2 operations. The primary outcomes were patient and graft survival. The secondary outcomes were postoperative complications and efficacy of weight loss.

RESULTS

Twenty-two patients were included in the KT first group and 34 in the BS first group. Death-uncensored graft survival in the KT first group was significantly higher than in the BS first group (90.9% versus 71.4%, P = .009), without significant difference in patient survival and death-censored graft survival (100% versus 90.5%, P = .082; 90.9% versus 81.0%, P = .058). There was no significant difference in 1-year total weight loss (1-yr TWL: median [interquartile range {IQR}], 36.0 [28.0-42.0] kg versus 29.6 [21.5-40.6] kg, P = .424), 1-year percentage of excess weight loss (1-yr %EWL: median [IQR], 74.9 [54.1-99.0] versus 57.9 [47.5-79.4], P = .155), and the incidence of postoperative complications (36.4% versus 50.0%, P = .316) between the KT first and BS first groups.

CONCLUSION

Both pre- and posttransplant BS are effective and safe. Different conditions of each transplant candidate should be considered in detail to determine the optimal timing of BS.

Comparison of Kidney Transplantation Outcomes Between Patients with and Without Pre-transplantation Bariatric Surgery: a Systematic Review

This systematic review evaluated the impact of bariatric surgery, performed to improve eligibility for kidney transplantation, on post-transplantation outcomes. A systematic literature search was performed for articles published by 30 January 2022. A total of 31 studies were included. Among patients without pre-transplantation bariatric surgery, 18 studies reported 13.7% graft loss and 9.1% mortality within 5 years' post-transplantation. Among recipients with pre-transplantation bariatric surgery, 15 studies reported 8.7% graft loss and 2.8% mortality within 1 month to over 5 years' post-transplantation. Two case-control studies comparing post-transplantation outcomes between recipients with and without prior bariatric surgery demonstrated no significant differences between groups for graft loss, patient mortality, delayed graft function, wound complications and lymphocele. Non-randomized selection of patients and different lengths of follow-up limit the results of this study.

Kidney Transplantation in Patients After Bariatric Surgery: High-Volume Bariatric and Transplant Center Experience

BACKGROUND

Kidney transplantation (KTx) is the best type of treatment for patients with end-stage renal disease (ESRD). Unfortunately, obesity may be a contraindication for transplantation. Our study aimed to evaluate the results of KTx in patients who had bariatric surgery (BS) prior to transplantation.

METHODS

A single center, with experience in bariatric and transplant surgery, presents a retrospective study of 13 patients who received a kidney transplant after a gastric bypass (GB) operation between 2012 and 2019.

RESULTS

Thirteen patients, who were potential candidates for KTx, were previously qualified for BS because of a body mass index (BMI) > 35 kg/m². Additionally, all patients had arterial hypertension, 60% of patients had diabetes, and 30% of patients had coronary artery disease. Patients were activated on the waiting list when their BMI was < 35 kg/m². KTx was performed between 5 and 29 months after BS. One patient needed reoperation due to a urinary leak and another patient needed reoperation because of a high-pressure lymphocele. We diagnosed 2 delayed graft functions (DGFs) and 1 acute rejection. One patient died for reasons independent of surgery. The KTx observation period ranged from 3 to 8 years. Currently, 11 patients has stable renal function: creatinine concentration is 0.8-1.8 mg/dL and BMI is between 23 and 35 kg/m².

CONCLUSIONS

Despite the small group of patients, we can assume that kidney transplantation can be safely performed in patients with end-stage renal disease (ESRD) who have previously undergone gastric bypass (GB) as a graft bridging procedure. In some cases, BS may be the only chance of getting an organ.

The Impact of Obesity and Associated Comorbidities on the Outcomes after Renal Transplantation with a Living Donor vs. Deceased Donor Grafts

Background: Obesity among kidney transplant (KT) recipients can lead to metabolic comorbidity-associated deaths. This study compares post-KT survival between obese and non-obese patients and outcomes of living donor (LD) and deceased donor (DD) grafts. Methods: Between January 2005−May 2019, 1403 KT recipients from a single center were included in the study, as well as 314 patients (22.4%) with obesity (BMI > 30 kg/m2), 137 DD transplants, and 177 LD transplants. Of the 1089 (77.6%) in the control group (BMI ≤ 30 kg/m2), 384 were DD transplants and 705 LD transplants. The Kaplan−Meier method was used for survival analysis and a Cox regression was used to identify risk factors for graft loss and mortality. Propensity score matching analysis adjusting for age, IHD, and T2DM was performed. Results: The study group had higher incidence of obesity related comorbidities, delayed graft function and primary non function (p < 0.001). One-, 5-and 10-year patient and graft survival were lower in the study group (p < 0.001). Subgroup analysis of graft survival according to type of graft shows a difference in the DD (p = 0.002) but not in the LD group (p = 0.220). However, mortality was higher in both groups (LD, p = 0.045; DD, p = 0.004). Risk factors for mortality were age, T2DM, IHD, and DD, and for graft failure: IHD, BMI, donor age, re-transplant, and DD. Propensity score analysis shows an odds ratio of 0.81 for graft failure and 0.93 for death in the study group (95% CI = 0.55, 1.21, p = 0.3 and CI = 0.59, 1.46, p = 0.7, respectively). Conclusions: Recipient age and metabolic comorbidities should be emphasized when evaluating patients with obesity. We suggest considering weight loss interventions using the new GLP-1 inhibitors and bariatric procedures in selected patients to prepare overweight patients for transplant.

The application of body mass index-based eligibility criteria may represent an unjustified barrier to renal transplantation in people with obesity

The prevalence of both obesity and end-stage kidney disease is increasing. In many centres, obesity is considered a relative contraindication to kidney transplantation due to an association with short- and longer-term adverse outcomes. This leads to delayed transplant waitlisting and longer organ waiting times for people with obesity. This review evaluates whether intentional pre-transplant weight loss in people with obesity improves kidney transplant outcomes. There are currently no data showing that non-surgical weight loss of 10% or more improves graft or patient survival over 4-5 years. Outcomes from bariatric surgery cohorts have been generally neutral or favourable after pre-transplant weight loss of ~25%. Given the survival benefit of kidney transplantation compared to maintenance dialysis, and the difficulty of achieving and maintaining weight loss, the common practice of recommending weight loss to achieve arbitrary targets prior to waiting list activation needs to be carefully considered.

Prevention of Post-Transplant Diabetes Mellitus: Towards a Personalized Approach

Post-transplant diabetes is a frequent complication after transplantation. Moreover, patients suffering from post-transplant diabetes have increased cardiovascular morbidity and reduced survival. Pathogenesis mainly involves beta-cell dysfunction in presence of insulin resistance. Both pre- and post-transplant risk factors are well-described, and some of them may be corrected or prevented. However, the frequency of post-transplant diabetes has not decreased in recent years. We realized a critical appraisal of preventive measures to reduce post-transplant diabetes.

Bariatric Surgery and Solid-Organ Transplantation

Morbid obesity and being overweight are a growing problem worldwide. They also affect patients with end-stage solid-organ disease and patients after transplant. Bariatric surgery is the most effective available weight loss procedure. Bariatric surgery can be helpful for the treatment of some conditions, such as nonalcoholic fatty liver disease or nonalcoholic steatohepatitis, which may lead to transplant, and weight loss can improve or even reverse them. In other cases, morbid obesity is a limitation to accessing a transplant program, so bariatric surgery can serve as a conduit to transplant. After transplant, obesity and obesity-related comorbidities can be a significant health problem that may be treated, as in patients without a transplant, with bariatric surgery. There are some specific conditions and issues to be considered in patients with end-stage solid-organ disease who are candidates for bariatric surgery, such as increased morbidity and mortality. After transplant, immunosuppressant regimens and technical limitations may be also significant.

Management of obesity in kidney transplant candidates and recipients: A clinical practice guideline by the DESCARTES Working Group of ERA

The clinical practice guideline Management of Obesity in Kidney Transplant Candidates and Recipients was developed to guide decision-making in caring for people with end-stage kidney disease (ESKD) living with obesity. The document considers the challenges in defining obesity, weighs interventions for treating obesity in kidney transplant candidates as well as recipients and reflects on the impact of obesity on the likelihood of wait-listing as well as its effect on transplant outcomes. It was designed to inform management decisions related to this topic and provide the backdrop for shared decision-making. This guideline was developed by the European Renal Association's Developing Education Science and Care for Renal Transplantation in European States working group. The group was supplemented with selected methodologists to supervise the project and provide methodological expertise in guideline development throughout the process. The guideline targets any healthcare professional treating or caring for people with ESKD being considered for kidney transplantation or having received a donor kidney. This includes nephrologists, transplant physicians, transplant surgeons, general practitioners, dialysis and transplant nurses. Development of this guideline followed an explicit process of evidence review. Treatment approaches and guideline recommendations are based on systematic reviews of relevant studies and appraisal of the quality of the evidence and the strength of recommendations followed the Grading of Recommendations Assessment, Development and Evaluation approach. Limitations of the evidence are discussed and areas of future research are presented.

Improvement of kidney function in patients with chronic kidney disease and severe obesity after bariatric surgery: A systematic review and meta-analysis

The general management for chronic kidney disease (CKD) includes treating reversible causes, including obesity, which may be both a driver and comorbidity for CKD. Bariatric surgery has been shown to reduce the likelihood of CKD progression and improve kidney function in observational studies. We performed a systematic review and meta-analysis of patients with at least stage 3 CKD and obesity receiving bariatric surgery. We searched Embase, MEDLINE, CENTRAL and identified eligible studies reporting on kidney function outcomes in included patients before and after bariatric surgery with comparison to a medical intervention control if available. Risk of bias was assessed with the Newcastle-Ottawa Risk of Bias score. Nineteen studies were included for synthesis. Bariatric surgery showed improved eGFR with a mean difference (MD) of 11.64 (95%CI: 5.84 to 17.45, I²  = 66%) ml/min/1.73m² and reduced SCr with MD of -0.24 (95%CI -0.21 to -0.39, I²  = 0%) mg/dl after bariatric surgery. There was no significant difference in the relative risk (RR) of having CKD stage 3 after bariatric surgery, with a RR of -1.13 (95%CI: -0.83 to -2.07, I²  = 13%), but there was reduced likelihood of having uACR >30 mg/g or above with a RR of -3.03 (95%CI: -1.44 to -6.40, I²  = 91%). Bariatric surgery may be associated with improved kidney function with the reduction of BMI and may be a safe treatment option for patients with CKD. Future studies with more robust reporting are required to determine the feasibility of bariatric surgery for the treatment of CKD.

Intensive management of obesity in people with severe chronic kidney disease: A review

Obesity is highly prevalent worldwide, including among people with chronic kidney disease (CKD). The presence of severe and/or end-stage kidney disease complicates the treatment of obesity for several reasons, including restrictions on protein and fluid intake and renal excretion of several medications indicated for the treatment of obesity. The aim of this review is to assess the safety of intensive obesity treatments, such as very-low-energy diets (VLEDs), obesity pharmacotherapy and/or bariatric surgery, in people with end-stage kidney disease. A literature search was conducted to identify studies reporting safety outcomes for VLEDs, liraglutide, phentermine, phentermine-topiramate, naltrexone-bupropion and bariatric surgery in people with an estimated glomerular filtration rate of less than 30 mL/min/1.73m² or on dialysis. Limited data were insufficient to recommend VLEDs but highlighted their potential efficacy and the need for close clinical and biochemical monitoring. There were no data regarding centrally acting obesity pharmacotherapy in this population, although some glucagon-like peptide-1 analogues appear to safely induce weight loss at doses used for the treatment of type 2 diabetes. Some studies suggest an increased rate of complications of bariatric surgery in individuals with severe or end-stage CKD. Further prospective evaluation of intensive obesity management in the growing population with obesity and severe, end-stage and dialysis-dependent CKD is required.

Postoperative outcomes after bariatric surgery in patients on chronic dialysis: A systematic review and meta-analysis

BACKGROUND

Obesity is a barrier to kidney transplantation for patients with kidney failure. Consequently, bariatric surgery is often considered as a bridge to transplantation, even though its risks and benefits are poorly characterised in the dialysis population.

METHODS

Systematic searches of observational studies indexed in Embase, MEDLINE and CENTRAL till April 2020 were performed to identify relevant studies. Risk of bias was assessed by the Newcastle Ottawa Scale and quality of evidence was summarised in accordance with GRADE methodology. Random effects meta-analyses were performed to obtain summary odds ratios for postoperative outcomes.

RESULTS

Four cohort studies involving 4196 chronic dialysis and 732,204 non-dialysis patients undergoing bariatric surgery were included. Sleeve gastrectomy (61%), and Roux-en-Y gastric bypass (29%) were the most common procedures performed. Absolute rates of adverse events were low, but the odds of postoperative mortality (0.4-0.5% vs. 0.1%; odds ratio [OR] 4.7, 95%CI 2.2-9.9), and myocardial infarction (0.0-0.5% vs. 0.1%, OR 3.4, 95% CI 2.0-5.9) were higher in dialysis compared to non-dialysis patients. Patients on dialysis also had more than 2-fold increased odds of returning to theatre and having a readmission. Rates of kidney transplant wait-listing among dialysis patients was 59%, with 28% of all patients eventually receiving a kidney transplant.

CONCLUSION

Patients receiving chronic dialysis have substantially increased odds of postoperative mortality and myocardial infarction following bariatric surgery compared with patient who do not have kidney failure. It is uncertain whether bariatric surgery improves the likelihood of kidney transplantation, with mid- to long-term outcomes being poorly described.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Lower Baseline Serum Triglyceride Levels Are Associated With Higher Decrease in Body Mass Index After Laparoscopy Sleeve Gastrectomy Among Obese Patients

AIMS

To investigate the predictive value of baseline serum triglyceride (TG) levels for improvements of metabolism after laparoscopic sleeve gastrectomy (LSG).

METHODS

112 obese patients [body mass index (BMI) ≥ 35 kg/m²] underwent LSG and with complete information of anthropometric and metabolic parameters were divided into normal TG group (group A) and high TG group (group B), while group A had TG levels ≤ 1.7 mmol/L, and group B had TG levels > 1.7 mmol/L. The post-operative changes (Δ) in metabolic parameters between the two groups were compared.

RESULTS

In the whole cohort, the metabolic parameters were significantly improved at 6 months after LSG. BMI and waist circumference (WC) decreased significantly in the two groups. The ΔBMI among group A and group B were 11.42±3.23 vs 9.13±2.77 kg/m² (p<0.001), respectively. ΔBMI was positively correlated with ΔWC (r=0.696, p<0.001), Δfasting insulin level (r=0.440, p=0.002), Δfasting serum C peptide level (r=0.453, p=0.002), and Δhomeostasis model assessment insulin resistance index (r=0.418, p=0.004) in group A. Compared with group B, group A had a significantly higher odds ratio (OR) of 2.83 (95% confidence interval [CI]1.25-6.38, p=0.012)and 2.73 (95% CI 1.11-6.72, p=0.029) for ΔBMI and ΔWC after adjustment for age and gender, respectively.

CONCLUSIONS

Obese patients with baseline TG levels under 1.7 mmol/L had greater loss of weight at six months follow-up later LSG. This finding suggests that baseline TG level may have a predictive value for weight loss, at least in the short-term follow-up.

Impaired dexamethasone resorption in two patients with pseudo-Cushing after bariatric surgery: Implications for immunosuppressive treatment

Two cases of middle-aged female patients treated by gastric bypass surgery for weight loss presented to our clinic for a follow-up examination 3-6 months after the surgical procedure (a mini gastric bypass and a modified single anastomosis sleeve-ileostomy). In both patients increased ACTH levels and either high serum cortisol or an increased urinary cortisol excretion was apparent and triggered further endocrine testing. Serum cortisol could not be suppressed adequately by 2 and 4 mg dexamethasone in the standardized oral overnight suppression test while midnight salivary cortisol dropped well below the desired cut-off. This led to the hypothesis of an impaired dexamethasone resorption and could be further substantiated by suppression of serum cortisol below the cut-off by an intravenous dexamethasone application. The data presented point to an impairment of enteral synthetic corticosteroid resorption in patients after gastric bypass surgery and could be of importance for individuals in need for immunosuppressive treatment. In view of the growing number of bariatric procedures, pharmacokinetics of corticosteroids and other drugs should be tested in clinical trials.

Bariatric surgery to achieve transplant in end-stage organ disease patients: A systematic review and meta-analysis

BACKGROUND

As obesity prevalence grows, more end-stage organ disease patients will be precluded from transplant. Numerous reports suggest bariatric surgery in end-stage organ disease may help patients achieve weight loss sufficient for transplant listing.

METHODS

We performed a systematic review/meta-analysis of studies of bariatric surgery to achieve solid organ transplant listing.

RESULTS

Among 82 heart failure patients, 40.2% lost sufficient weight for listing, 29.3% were transplanted, and 8.5% had sufficient improvement with weight loss they no longer required transplantation. Among 28 end-stage lung disease patients, 28.6% lost sufficient weight for listing, 7.1% were transplanted, and 14.3% had sufficient improvement following weight loss they no longer required transplant. Among 41 cirrhosis patients, 58.5% lost sufficient weight for listing, 41.5% were transplanted, and 21.9% had sufficient improvement following weight loss they no longer required transplant. Among 288 end-stage/chronic kidney disease patients, 50.3% lost sufficient weight for listing and 29.5% were transplanted.

CONCLUSIONS

Small sample size and publication bias are limitations; however, bariatric surgery may benefit select end-stage organ disease patients with obesity that precludes transplant candidacy.

Laparoscopic sleeve gastrectomy for morbid obesity in renal transplantation candidates: a matched case-control study

Obesity has become an important issue in patients with end-stage renal disease (ESRD). Since it is considered a relative contraindication for renal transplantation, bariatric surgery has been advocated to treat morbid obesity in transplant candidates, and laparoscopic sleeve gastrectomy (LSG) is the most reported procedure. However, comparative data regarding outcomes of LSG in patients with or without ESRD are scarce. Consecutive patients with ESRD (n = 29) undergoing LSG were compared with matched patients with normal renal function undergoing LSG in a 1:3 ratio using propensity score adjustment. Data were collected from a prospective database. Eligibility for transplantation was also studied. A lower weight loss (20 kg (16-30)) was observed in patients with ESRD within the first year as compared to matched patients (28 kg (21-34)) (P < 0.05). After a median follow-up of 30 (19-50) months in the ESRD group, contraindication due to morbid obesity was lifted in 20 patients. Twelve patients underwent transplantation. In patients with ESRD potentially eligible for transplantation, LSG allows similar weight loss in comparison with matched patients with normal renal function, enabling lifting contraindication for transplantation due to morbid obesity in the majority of patients within the first postoperative year.

Abdominal Organ Transplantation: Noteworthy Literature in 2019

In the year 2019, we identified and screened over 400 peer-reviewed publications on pancreatic transplantation, over 200 on intestinal transplantation, and over 1900 on kidney transplantation. The liver transplantation section focuses on and features selected articles among 70 clinical trials published in 2019. This review highlights noteworthy literature pertinent to anesthesiologists and critical care physicians caring for patients undergoing abdominal organ transplantation. We explore a broad range of topics, including risks for and prediction of perioperative complications, updated indications for transplantation, recommendations on perioperative management, including Enhanced Recovery After Surgery programs, and topics relevant to optimization of patient and graft outcomes and survival.

Metabolic Surgery to Treat Obesity in Diabetic Kidney Disease, Chronic Kidney Disease, and End-Stage Kidney Disease; What Are the Unanswered Questions?

Obesity is a major factor in contemporary clinical practice in nephrology. Obesity accelerates the progression of both diabetic and non-diabetic chronic kidney disease and, in renal transplantation, both recipient and donor obesity increase the risk of allograft complications. Obesity is thus a major driver of renal disease progression and a barrier to deceased and living donor kidney transplantation. Large observational studies have highlighted that metabolic surgery reduces the incidence of albuminuria, slows chronic kidney disease progression, and reduces the incidence of end-stage kidney disease over extended follow-up in people with and without type 2 diabetes. The surgical treatment of obesity and its metabolic sequelae has therefore the potential to improve management of diabetic and non-diabetic chronic kidney disease and aid in the slowing of renal decline toward end-stage kidney disease. In the context of patients with end-stage kidney disease, although complications of metabolic surgery are higher, absolute event rates are low and it remains a safe intervention in this population. Pre-transplant metabolic surgery increases access to kidney transplantation in people with obesity and end-stage kidney disease. Metabolic surgery also improves management of metabolic complications post-kidney transplantation, including new-onset diabetes. Procedure selection may be critical to mitigate the risks of oxalate nephropathy and disruption to immunosuppressant pharmacokinetics. Metabolic surgery may also have a role in the treatment of donor obesity, which could increase the living kidney donor pool with potential downstream impact on kidney paired exchange programmes. The present paper provides a comprehensive coverage of the literature concerning renal outcomes in clinical studies of metabolic surgery and integrates findings from relevant mechanistic pre-clinical studies. In so doing the key unanswered questions for the field are brought to the fore for discussion.