Bariatric surgery for prospective living kidney donors with obesity?

Preoperative Laparoscopic Sleeve Gastrectomy Improves Weight Loss Potential in Morbidly Obese Voluntary Kidney Donors

BACKGROUND

This was a retrospective study aimed at evaluating the efficacy of laparoscopic sleeve gastrectomy (LSG) as a strategy for weight loss in obese prospective voluntary kidney donors who were unable to achieve weight reduction through lifestyle changes.

METHODS

This retrospective study included living kidney donors who underwent LSG as a strategy for weight loss in obese prospective voluntary kidney donors between 2012 and 2022. Prospective donors who were initially rejected due to obesity underwent LSG after pretransplantation evaluation. Changes in weight, body mass index (BMI), and laboratory parameters (hemogram, kidney function tests, liver function tests, fasting and postprandial glycemia, HbA1c, and lipid profile measurements) were recorded before bariatric surgery and before nephrectomy.

RESULTS

Of the 16 candidates who underwent LSG, one did not proceed with donor nephrectomy due to the intended recipient's death. Among the remaining 15 subjects, the average interval between bariatric surgery and donor nephrectomy was 165.95 ± 48.86 days. There was a significant decrease in BMI following bariatric surgery (P < .0001); the mean BMI before bariatric surgery was 40.94 ± 4.53 kg/m², and before nephrectomy, it was 30.91 ± 3.87 kg/m2. The mean weight loss was 22.64 ± 5.75 kg.

CONCLUSION

This study supports LSG as an effective approach for obese individuals who are potential kidney donors to achieve weight loss, mitigate obesity-associated risks, and become successful kidney donors.

Bariatric surgery in prospective obese living kidney donors: scoping review and management decision algorithm

INTRODUCTION

Global chronic kidney disease is now epidemic, with substantial health and economic consequences. While scientific support for living donor renal transplants (LDRT) is strong, donor shortages necessitate consideration of expanded criteria, including obese individuals. Bariatric surgery (BS) may mitigate obesity-related risks, but research on living donor candidates is scarce. Our scoping review aims to compile evidence, identify gaps, and formulate an algorithm to guide healthcare professionals in evaluating BS for obese living donors.

EVIDENCE ACQUISITION

We did a systematic search of studies on living kidney donors and obesity. We searched the MEDLINE Ovid, Embase Ovid, CENTRAL and Web of Science databases for studies from database inception to March 30, 2023. All English-language articles available in full text have been considered. Excluded are commentaries, editorials, letters, and abstracts.

EVIDENCE SYNTHESIS

Obesity in LDRT raises long-term ESRD risk. Current high BMI donor admission raises ethical and clinical concerns. Encouraging timely weight loss can make obese candidates suitable donors, reducing risks. Sleeve gastrectomy is the most reported and preferable approach, since it minimizes hyperoxaluria risk. Re-evaluation for donation is possible 6-12 months post-BS, with BMI<35 for three months. Cost-benefit analysis favors BS over nephrectomy in obese donors (cost-benefit ratio: 3.64) when graft survival is equal.

CONCLUSIONS

BS shows promise with short-term effectiveness and potential long-term outcomes. However, it should not be perceived as a means to expand the donor pool but rather as a personalized approach to address obesity and improve individuals' health.

Antiobesity pharmacotherapy to facilitate living kidney donation

Obesity is a chronic, relapsing disease that increases the risks of living kidney donation; at the same time, transplant centers have liberalized body mass index constraints for donors. With the increasing number of antiobesity medications available, the treatment of obesity with antiobesity medications may increase the pool of potential donors and enhance donor safety. Antiobesity medications are intended for long-term use given the chronic nature of obesity. Cessation of treatment can be expected to lead to weight regain and increase the risk of comorbidity rebound/development. In addition, antiobesity medications are meant to be used in conjunction with-rather than in replacement of-diet and physical activity optimization. Antiobesity medication management includes selecting medications that may ameliorate any coexisting medical conditions, avoiding those that are contraindicated in such conditions, and being sensitive to any out-of-pocket expenses that may be incurred by the potential donor. A number of questions remain regarding who will and should shoulder the costs of long-term obesity treatment for donors. In addition, future studies are needed to quantify the degree of weight loss and duration of weight loss maintenance needed to normalize the risk of adverse kidney outcomes relative to comparable nondonors and lower-weight donors.

The Impact and Effectiveness of Weight Loss on Kidney Transplant Outcomes: A Narrative Review

Obesity is a worldwide epidemic that leads to several non-communicable illnesses, including chronic kidney disease (CKD). Diet and lifestyle modifications have shown a limited impact in the treatment of obesity. Because the group of end-stage renal disease (ESRD) patients examined in this study had limited access to kidney transplantation (KT), patients with obesity were thought to be at an increased risk of intraoperative and postoperative KT complications. Although bariatric surgery (BS) is now recognized as the gold standard treatment for morbid obesity, its role in ESRD or kidney transplant patients remains unknown. It is critical to know the correlation between weight loss and complications before and after KT, the impact of the overall graft, and patients' survival. Hence, this narrative review aims to present updated reports addressing when to perform surgery (before or after a KT), which surgical procedure to perform, and again, if strategies to avoid weight regain must be specific for these patients. It also analyzes the metabolic alterations produced by BS and studies its cost-effectiveness pre- and post-transplantation. Due to the better outcomes found in KT recipients, the authors consider it more convenient to perform BS before KT. However, more multicenter trials are required to provide a solid foundation for these recommendations in ERSD patients with obesity.

Population-based Trends in Obesity and Kidney Transplantation Among Patients With End-stage Kidney Disease

Obesity is a barrier to transplant, reducing access and leading to worse outcomes versus nonobese adults. Most transplant centers in the United States maintain body mass index (BMI) cutoffs to listing for kidney transplantation of 35 to 40 kg/m². There is little contemporary data on the prevalence of obesity among patients with end-stage kidney disease (ESKD) despite its impact on clinical outcomes and healthcare expenditures.

Methods

We utilized data from the US Renal Data System from 2008 to 2016 to identify a prevalent cohort of 1 079 410 patients with ESKD. Linear regression determined trends in the proportion of patients within each category of BMI. We also evaluated geographic variation in rates of obesity and transplantation across the United States.

Results

Among the 1 079 410 ESKD patients, the largest cohort of patients were those with obesity (n = 423 270; 39.2%). There were 309 707 (28.7%) patients with an overweight BMI and 274 683 (25.4%) with a normal BMI. The proportion of patients with obesity increased significantly from 36.8% in 2008 to 40.2% in 2016 (trend 0.28; 95% confidence interval, 0.05-0.51). There was significant geographic variation by state with rates of obesity ranging from 32.3% to 45.4% and state transplant rates among those obese patients ranging from 22.5% to 46.8%. There is a weak correlation between states with increased rates of obese ESKD patients and states with an increased obesity transplant rate as indicated with r = 0.40 (P = 0.003).

Conclusions

Beneficiaries with obesity are now the largest and fastest growing demographic among patients with ESKD in the United States.

Obesity and bariatric surgery in kidney transplantation: A clinical review

Obesity is increasing worldwide, and this has major implications in the setting of kidney transplantation. Patients with obesity may have limited access to transplantation and increased posttransplant morbidity and mortality. Most transplant centers incorporate interventions aiming to target obesity in kidney transplant candidates, including dietary education and lifestyle modifications. For those failing nutritional restriction and medical therapy, the use of bariatric surgery may increase the transplant candidacy of patients with obesity and end-stage renal disease (ESRD) and may potentially improve the immediate and late outcomes. Bariatric surgery in ESRD patients is associated with weight loss ranging from 29.8% to 72.8% excess weight loss, with reported mortality and morbidity rates of 2% and 7%, respectively. The most commonly performed bariatric surgical procedures in patients with ESRD and in transplant patients are laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass. However, the correct timing of bariatric surgery and the ideal type of surgery have yet to be determined, although pretransplant LSG seems to be associated with an acceptable risk-benefit profile. We review the impact of obesity on kidney transplant candidates and recipients and in potential living kidney donors, exploring the potential impact of bariatric surgery in addressing obesity in these populations, thereby potentially improving posttransplant outcomes.

[Living donor nephrectomy: The French guidelines from CTAFU]

OBJECTIVE

To propose surgical recommendations for living donor nephrectomy.

METHOD

Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU regarding functional and anatomical assessment of kidney donors, including which side the kidney should be harvested from. Distinct surgical techniques and approaches were evaluated. References were considered with a predefined process to propose recommendations with the corresponding levels of evidence.

RESULTS

The recommendations clarify the legal and regulatory framework for kidney donation in France. A rigorous assessment of the donor is one of the essential prerequisites for donor safety. The impact of nephrectomy on kidney function needs to be anticipated. In case of modal vascularization of both kidneys without a relative difference in function or urologic abnormality, removal of the left kidney is the preferred choice to favor a longer vein. Mini-invasive approaches for nephrectomy provide faster donor recovery, less donor pain and shorter hospital stay than open surgery.

CONCLUSION

These French recommendations must contribute to improving surgical management of candidates for kidney donation.

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.

Novel approaches to sarcopenic obesity and weight management before and after kidney transplantation

PURPOSE OF REVIEW

Although a widely recognized and complex pathophysiological condition, sarcopenic obesity remains less appreciated and may elude diagnosis and workup in both kidney transplant waitlisted candidates and kidney transplant recipients. The lack of consensus definition, and practical diagnostic tools for evaluating waitlisted candidates and transplant recipients are barriers to early detect and initiate therapeutic management for sarcopenic obesity. Although sarcopenia leads to poor clinical outcomes, posttransplant obesity yields conflicting results. Exercise and nutritional managements are common therapies for sarcopenic obese patients; however, surgery weight loss or bariatric surgery in both transplant candidates and potential living kidney donors shows promising benefits for kidney transplant access in waitlist obese candidates but may require to be selected for appropriate patients.

RECENT FINDINGS

Pathogenesis and management for sarcopenia and obesity are interconnected. The benefits of exercise to improve muscle mass and function is clear in waitlist kidney transplant candidates and transplant recipients. However, there are several barriers for those to increase exercise and improve physical activity including patient, provider, and healthcare or environmental factors. The advantages of fat mass reduction to lose weight can promote muscle mass and strength. However, epidemiological data regarding the obesity paradox in dialysis-dependent patients when overnutrition provides survival benefits for this population should be taken into account when performing weight loss especially bariatric surgery.

SUMMARY

Barriers in providing optimal care to kidney transplant waitlisted candidates and transplant recipients may partly result from underdiagnosis of sarcopenic obesity; notwithstanding that this entity has increasingly been more recognized. Mechanistic studies to better understand pathogenesis of sarcopenic obesity will help determine pathogenesis and clinical tools for diagnosis of this entity, which can facilitate further studies related to the outcomes and weight management to ultimately improve kidney transplant outcomes.

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.

Trends in Bariatric Surgery Procedures among Patients with ESKD in the United States

BACKGROUND AND OBJECTIVES

Despite the potential for improving health status or increasing access to transplantation, national practice patterns for bariatric surgery in obese patients with ESKD are poorly understood. The purpose of this study was to describe current trends in surgical care for this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using 100% Medicare data, we identified all beneficiaries undergoing bariatric surgery in the United States between 2006 and 2016. We evaluated longitudinal practice patterns using linear regression models. We also estimated risk-adjusted complications, readmissions, and length of stay using Poisson regression for patients with and without ESKD.

RESULTS

The number of patients with ESKD undergoing bariatric surgery increased ninefold between 2006 and 2016. The proportional use of sleeve gastrectomy increased from <1% in 2006 to 84% in 2016. For sleeve gastrectomy, complication rates were similar between patients with and without ESKD (3.4% versus 3.6%, respectively; difference, -0.3%; 95% confidence interval, -1.3% to 0.1%; P=0.57). However, patients with ESKD had more readmissions (8.6% versus 5.4%, respectively; difference, 3.2%; 95% confidence interval, 1.9% to 4.6%; P<0.001) and slightly longer hospitals stays (2.2 versus 1.9 days, respectively; difference, 0.3; 95% confidence interval, 0.1 to 0.4; P<0.001).

CONCLUSIONS

This study suggests that laparoscopic sleeve gastrectomy has replaced Roux-en-Y gastric bypass as the most common bariatric surgical procedure in patients with ESKD. The data also demonstrate a favorable complication profile in patients with sleeve gastrectomy.