Laparoscopic sleeve gastrectomy as a weight reduction strategy in obese patients after kidney transplantation

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.

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.

Bariatric surgery outcomes following organ transplantation: A review study

Weight gain is a frequent postoperative complication following a solid organ transplant which can be solved by bariatric surgery. The outcomes of bariatric surgery among patients with an organ transplant history are always a challengeable subject for surgeons and surgery candidates. In this review article, we aim to investigate the existence literature about the rates of morbidity and mortality, frequent complications in terms of graft function, remission in diabetes, hypertension, pulmonary and cardiovascular disorders, hepatic and renal functions, and immunosuppressive stability, as well as the safety of bariatric surgery among patients.

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.

Effects of obesity and weight-loss surgery shift the microbiome and impact alloimmune responses

PURPOSE OF REVIEW

Obesity is a worldwide health problem with increasing rates in both children and adults. Bariatric surgery (BS) represents the only effective long-term treatment. Beneficial effects of BS may be mediated through shifts of the gut microbiome. Here, we introduce data linking the microbiome to alloimmune responses.

RECENT FINDINGS

The rapid development of microbiome sequencing technologies in addition to the availability of gnotobiotic facilities have enabled mechanistic investigations on modulations of alloimmune responses through microbiomes. BS has been shown to improve comorbidities and chronic inflammation caused by obesity. Changes in microbiota and microbiota-related metabolites may play a role. Patients either listed or having received a transplant have undergone weight loss surgery, thus allowing to dissect mechanisms of microbial shifts to alloimmunity.

SUMMARY

Weight loss and BS have the potential to improve transplant outcomes by ameliorating alloimmune responses. Those effects may be carried out through alterations of the gut microbiome.

Bariatric surgery prior to transplantation and risk of early hospital re-admission, graft failure, or death following kidney transplantation

Bariatric surgery has been shown to be safe in the dialysis population. Whether bariatric surgery before kidney transplantation influences posttransplant outcomes has not been examined nationally. We included severely obese (BMI >35) dialysis patients between 18 and 70 years who received a kidney transplant according to the US Renal Data System. We determined the association between history of bariatric surgery and risk of 30-day readmission, graft failure, or death after transplantation using multivariable logistic, Fine-Gray, and Cox models. We included 12 573 patients, of whom 503 (4%) received bariatric surgery before transplantation. Median age at transplant was 53 years; 42% were women. Overall, history of bariatric surgery was not statistically significantly associated with graft failure (HR 1.02; 95% CI 0.77-1.35) or death (HR 1.10; 95% CI 0.84-1.45). However, sleeve gastrectomy (vs. no bariatric surgery) was associated with lower risk of graft failure (HR 0.39; 95% CI 0.16-0.95). In conclusion, history of bariatric surgery prior to kidney transplantation was not associated with allograft or patient survival, but findings varied by surgery type. Sleeve gastrectomy was associated with better graft survival and should be considered in severely obese transplant candidates receiving dialysis.

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.

Bariatric surgery in transplant recipients: A narrative review

Morbidity and mortality rates are increased due to obesity after organ transplantation; in this regards, bariatric surgery (BS) is believed to be an effective treatment for posttransplant obese patients. Nevertheless, some studies are doubtful in terms of the effectiveness of BS, the most suitable bariatric procedure, and management of immunosuppressant drugs in some kinds of organ transplants. We evaluated nonsurgical therapies, weight reduction, adjustment of immunosuppressants, comorbidities, and the recommended surgical procedures for posttransplant BS for different types of organ transplantations.

Long-term outcomes of Roux-en-Y gastric bypass or sleeve gastrectomy in patients with cirrhosis; before, during or after liver transplantation: A single center's experience

BACKGROUND

The increasing prevalence of morbid obesity (MO) results in parallel growth of obesity-associated liver diseases necessitating liver transplantation (LT).

OBJECTIVE

To examine the feasibility and safety of Roux-en-Y gastric bypass or sleeve gastrectomy in the setting of LT.

METHODS

This retrospective chart review included the data on all the MO candidates before and after LT who underwent bariatric surgery (BS) in our institution between 04/2013-09/2016. The reported outcomes were weight change and early and late postoperative complications (mean follow-up: 43 ± 11.1 months).

RESULTS

Eighteen MO peri-LT patients (10 females, 8 males, average age 48 years) were included in the study. Ten had cirrhosis (mean Model of End-stage Liver Disease [MELD] score of 12.5 ± 6.42), three underwent concurrent LT and BS (mean MELD score 23.7 ± 0.58), and five had LT (mean of 56 months from LT). The mean percentage of total and excess weight loss was 31% and 81%, respectively. Six of the eight patients with type 2 diabetes mellitus became normoglycemic after BS. Three patients sustained perioperative complications. Two cirrhotic patients died 1 and 4.5 years after BS with decompensation.

CONCLUSIONS

Bariatric surgery appears to effectively address obesity in cirrhotic and LT patients. The surgical risk is higher than that of the regular BS population.

Feasibility and impact of laparoscopic sleeve gastrectomy after renal transplantation on comorbidities, graft function and quality of life

Background

The aim of this study is to clarify the feasibility and effect of laparoscopic sleeve gastrectomy (LSG) on comorbidities, graft function and quality of life in patients who underwent renal transplantation (RT).

Methods

This is a retrospective review of five patients who underwent LSG after RT. Demographic data, anthropometric parameters, the effect on comorbidities, postoperative course, immunosuppressive medications, causes of RT, renal function, the survival of graft, and quality of life after SG in obese patients with a history of RT were assessed using BAROS–Moorhead–Ardelt survey

Results

From September 2015 to September 2019, 5 renal transplant patients underwent LSG; three female, and two male. Median body mass index (BMI) decreased from 42.17 kg/m² (range 36–55) before surgery to 28.16 kg/m² (range 25–42) after surgery. Improvement in blood pressure, triglyceride, and cholesterol levels was observed, and all cases were able to decrease their medications. Insulin was stopped and replaced with linagliptin in all diabetic patients. Graft function improved, and proteinuria level decreased in all cases. All patients reported to have an excellent quality of life.

Conclusion

LSG showed excellent outcomes in this high-risk group of patients regarding comorbidities, graft function and quality of life

Bariatric Surgery Outcomes in Patients with Previous Organ Transplant: Scoping Review and Analysis of the MBSAQIP

BACKGROUND

Obesity is a major risk factor for transplant. Laparoscopic bariatric surgery (LBS) offers transplant patient benefits including improved comorbidities, graft function, and longevity. We completed a scoping review and analyzed the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) to determine the risk-benefit profile of LBS after transplant. We also compared laparoscopic sleeve gastrectomy (LSG) to laparoscopic Roux-en-Y gastric bypass (LRYGB) following transplant.

METHODS

Univariate analysis determined between group differences with subgroup analysis comparing LSG versus LRYGB in transplant patients. Multivariable analysis assessed whether prior transplant was independently associated with major complications or mortality.

RESULTS

A total of 469 (0.1%) patients had previous transplant and had more comorbidities and more often underwent LSG. Operative time (93.9 min vs 83 min, p < 0.001) and length of stay were longer. Major complications were threefold higher in patients with a transplant history (9.6% vs 3.2%; p < 0.001. Previous transplant was the second greatest independent predictor for major complication (OR 2.14 [1.54-2.98], p = < 0.001) but was not predictive of death (OR 1.06 [0.14-8.13] p = 0.956). Amongst transplant patients, LRYGB demonstrated higher rates of leak (n = 1), VTE, AKI, unplanned intubation, and readmission.

CONCLUSIONS

The 30-day complication rate from LBS is three times higher amongst patients with a transplant. LSG is likely the best surgical approach. Despite risks, post-transplant patients incur important benefits from LBS. Surgeons must be aware of this risk-benefit profile when determining LBS candidacy.

Implications for body weight extremes in solid organ transplantation

The pharmacokinetic profiles of medications are altered in overweight and underweight patients, but few studies have described these differences in patients with body mass index extremes. As solid organ transplant programs expand their candidate selection criteria to accommodate a growing population of patients with weight extremes, it has become imperative to understand and evaluate the impact weight extremes have on the pharmacokinetics of life-sustaining immunosuppression in this population. This review will describe pharmacokinetic and dosing considerations for weight extremes in solid organ transplant recipients, including changes following bariatric surgeries, non-pharmacologic and pharmacologic management strategies for weight loss and gain, and potential drug-drug interactions with popular weight management products.

Effectiveness and Safety of Bariatric Surgery in Patients with End-Stage Chronic Kidney Disease or Kidney Transplant

OBJECTIVE

This study aimed to evaluate (1) the effectiveness, complications, and postoperative access to transplantation in end-stage chronic kidney disease (ECKD) and (2) the effectiveness and complications of bariatric surgery in patients who had already undergone kidney transplant.

METHODS

A systematic review and meta-analysis of mortality and complications rates were performed. Thirty studies were reviewed.

RESULTS

After bariatric surgery, patients with ECKD had similar postoperative weight loss to patients from the general population. Meta-analysis showed post-bariatric surgery rates of 2% (95% CI: 0%-3%) for mortality and 7% (95% CI: 2%-14%) for complications. Approximately one-fifth of the patients had access to a transplant. This rate may be underestimated because of the short duration of follow-up. The lack of control groups did not allow for a conclusion on the role of bariatric surgery in facilitating access to kidney transplantation. In patients who had received a kidney transplant, bariatric surgery seemed to improve renal function but increased graft-rejection risk, possibly because of changes in the bioavailability of immunosuppressant drugs.

CONCLUSIONS

Bariatric surgery yields significant weight loss in patients with ECKD that improves patients' chances of accessing a transplant but does not guarantee it; however, the risk for complications and death is higher than in other patients. After transplantation, bariatric surgery-induced weight loss appeared to positively impact the function of the grafted kidney, but careful monitoring of immunosuppressant medications is required.

Perioperative risks of bariatric surgery among patients with and without history of solid organ transplant

Bariatric surgery is effective among patients with previous transplant in limited case series. However, the perioperative safety of bariatric surgery in this patient population is poorly understood. Therefore, we assessed the safety of bariatric surgery among previous-transplant patients using a database that captures >92% of all US bariatric procedures. All primary, laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass procedures between 2017 and 2018 were identified from the MBSAQIP dataset. Patients with previous transplant (n = 610) were compared with patients without previous transplant (n = 321 447). Primary outcomes were 30 day readmissions, surgical complications, medical complications, and death. Multivariable logistic regression with predictive margins was used to compare outcomes. Previous transplant patients experienced higher incidence of readmissions (8.0% vs 3.5%), surgical complications (5.0% vs 2.7%), and medical complications (4.3% vs 1.5%). There was no difference in incidence of death (0.2% vs 0.1%). Among individual complications, there no statistical differences in intraabdominal leak, unplanned reoperation, myocardial infarction, or infectious complications. Baseline estimated glomerular filtration rate was found to be a strong moderator of primary outcomes, with the highest risk of complications occurring at the lowest baseline estimated glomerular filtration rate. Given the many long-term benefits of bariatric surgery among patients with previous transplant, our findings should not preclude this patient population from operative consideration.

Bariatric surgery before and after kidney transplantation: long-term weight loss and allograft outcomes

BACKGROUND

Severe obesity is frequently a barrier to kidney transplantation, and kidney transplant recipients often have significant weight gain following transplantation.

OBJECTIVES

The goals of this study were to evaluate the long-term risks and benefits of bariatric surgery before and after kidney transplantation.

SETTING

University Hospital, United States.

METHODS

We performed a retrospective cohort study of 43 patients who had pretransplantation bariatric surgery and 21 patients who had posttransplantation bariatric surgery from 1994 to 2017 with propensity-score matching to identify matched controls using national registry data.

RESULTS

Body mass index at the time of transplantation was similar in patients who underwent bariatric surgery before versus after transplantation (32 versus 34 kg/m², P = .172). There was no significant difference in body mass index in the 5 years after bariatric surgery among patients who underwent bariatric surgery before versus after kidney transplantation (36 versus 32 kg/m², P = 0.814). Compared with matched controls, bariatric surgery before (n = 38) and after (n = 18) kidney transplantation was associated with a decreased risk of allograft failure (hazard ratio .31 [95% confidence interval .29-0.33] and .85 [95% confidence interval .85-.86] for pre- and posttransplant, respectively) and mortality (hazard ratio .57 [95% confidence interval .53-.61] and .80 [95% confidence interval .79-.82] for pre- and posttransplant, respectively).

CONCLUSIONS

Bariatric surgery before and after kidney transplantation results in similar maintenance of weight loss and improved long-term allograft survival compared with matched controls. Bariatric surgery appears to be a safe and reasonable approach to weight loss both before and after transplantation.

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

BACKGROUND

The surgical risk of morbidly obese patients is high and even higher for kidney transplant candidates. A BMI > 35-40 kg/m² is often a contraindication for that surgery. The safety, feasibility, and outcome of bariatric surgery for those patients are inconclusive.

METHODS

We conducted a retrospective chart review of prospectively collected data on morbidly obese renal transplant candidates who underwent laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB) in our institution between January 2009 and September 2017. The reported outcome included body weight and graft status after a mean follow-up of 47 months (range 0.5-5 years).

RESULTS

Twenty-four patients (8 females, 16 males, average age 54 years, average preoperative BMI 41 kg/m² [range 35-51]) underwent LSG (n = 17) or LRYGB (n = 7). Sixteen of them (67%) proceeded to kidney transplantation. Of the 8 pre-transplant and post-bariatric surgery patients, 5 are on the waitlist, and 2 patients died (one of staple line leakage, and one from sepsis unrelated to the bariatric surgery). The average time from bariatric surgery to transplantation was 1.5 years (range 1 month to 4.3 years). The average pre-transplantation BMI was 28 kg/m² (range 19-36). The mean percentage of excess weight loss was 66% (n = 21), and the total percentage of weight loss was 29% (n = 21). Comorbidities (type 2 diabetes, hypertension, and dyslipidemia) improved significantly following both surgical approaches.

CONCLUSIONS

LSG and LRYGB appear to effectively address obesity issues before kidney transplantation and improve surgical access. Morbidly obese transplant candidates would benefit from prior bariatric surgery.

The Effects of Bariatric Surgery on Renal Outcomes: a Systematic Review and Meta-analysis

BACKGROUND/OBJECTIVE

Although promising, data regarding the renal impact and safety of bariatric surgery (BS) are insufficient. We aimed at investigating the benefits and harms of BS for weight loss on kidney function.

METHODS

A systematic review and meta-analysis of observational studies reporting data about the impact of BS (any techniques) on serum/plasma creatinine, creatinine clearance, glomerular filtration rate (GFR), proteinuria, nephrolithiasis, and need for renal replacement therapy (RRT)) was performed. Obese adults (non-chronic kidney disease (CKD), CKD or transplanted patients) that underwent BS for weight loss were included. After searching MEDLINE (inception to August 2017), the Cochrane Library (Issue 10-12, October 2017), and the websiteclinicaltrials.gov (August 2017), data were extracted and summarized using a random-effects model.

RESULTS

The final analysis included 23 cohort studies, comprising 3015 participants. Compared with renal function before treatment, BS significantly decreased serum creatinine level (mean difference (MD), - 0.08 mg dl^-1; 95% confidence interval (CI), - 0.10 to - 0.06); p < 0.001) and proteinuria (MD, - 0.04 g 24 h^-1; 95% CI, - 0.06 to - 0.02; p < 0.001) in the overall group. GFR significantly improved 6 months or more after BS both in the hyperfiltration and CKD subgroups. Renal function also tended to improve in renal transplant patients. Data on nephrolithiasis and the need for RRT were scarce or not reported.

CONCLUSIONS

BS apparently has positive effects on kidney function and tends to normalize GFR across different categories of renal impairment (hyperfiltration and CKD patients).

Obesity in Kidney Transplantation: Impact on Transplant Candidates, Recipients, and Donors

Obesity is now common among children and adults who are kidney transplant candidates and recipients. It is associated with an increased risk of cardiovascular disease and kidney failure. This also pertains to potential living kidney donors with obesity. Obese patients with end-stage renal disease benefit from transplantation as do nonobese patients, but obesity is also associated with more risk. A complicating factor is that obesity is also associated with increased survival on maintenance dialysis in adults, but not in children. The assessment of obesity and body habitus should be individualized. Body mass index is a common but imperfect indicator of obesity. The medical management of obesity in renal failure patients is often unsuccessful. Bariatric surgery, specifically laparoscopic sleeve gastrectomy, can result in significant weight loss with reduced morbidity, but many patients do not agree to undergo this treatment. The best approach to manage obese transplant candidates and recipients is yet unresolved.

Non-immunological complications following kidney transplantation

Kidney transplantation (KT) is the most effective way to decrease the high morbidity and mortality of patients with end-stage renal disease. However, KT does not completely reverse the damage done by years of decreased kidney function and dialysis. Furthermore, new offending agents (in particular, immunosuppression) added in the post-transplant period increase the risk of complications. Cardiovascular (CV) disease, the leading cause of death in KT recipients, warrants pre-transplant screening based on risk factors. Nevertheless, the screening methods currently used have many shortcomings and a perfect screening modality does not exist. Risk factor modification in the pre- and post-transplant periods is of paramount importance to decrease the rate of CV complications post-transplant, either by lifestyle modification (for example, diet, exercise, and smoking cessation) or by pharmacological means (for example, statins, anti-hyperglycemics, and so on). Post-transplantation diabetes mellitus (PTDM) is a major contributor to mortality in this patient population. Although tacrolimus is a major contributor to PTDM development, changes in immunosuppression are limited by the higher risk of rejection with other agents. Immunosuppression has also been implicated in higher risk of malignancy; therefore, proper cancer screening is needed. Cancer immunotherapy is drastically changing the way certain types of cancer are treated in the general population; however, its use post-transplant is limited by the risk of allograft rejection. As expected, higher risk of infections is also encountered in transplant recipients. When caring for KT recipients, special attention is needed in screening methods, preventive measures, and treatment of infection with BK virus and cytomegalovirus. Hepatitis C virus infection is common in transplant candidates and in the deceased donor pool; however, newly developed direct-acting antivirals have been proven safe and effective in the pre- and post-transplant periods. The most important and recent developments on complications following KT are reviewed in this article.

Bariatric surgery in solid organ transplant patients: Long-term follow-up results of outcome, safety, and effect on immunosuppression

The surgical risk of transplanted patients is high, and the modified gastrointestinal anatomy after bariatric surgery (BS) may lead to pharmacokinetic alterations in the absorption of immunosuppressive drugs. Data on outcomes of BS and the safety and feasibility of maintaining immunosuppression and graft safety among solid organ transplanted patients are scarce. In the current study, weight loss, improvement in comorbidities, and changes in dosage and trough levels of immunosuppression drugs before and after BS were analyzed for all transplanted patients who underwent laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB) in our institution between November 2011 and January 2017. Thirty-four patients (13 females, 21 males, average age 53 years) were included in the study. A successful weight loss (>50% excess weight loss in 28 of them [82%]) was recorded at the last follow-up. Comorbidities improved significantly. Immunosuppressive stability increased from 39% to 47% among all patients. The tacrolimus blood trough levels declined slightly, but remained within therapeutic range. These data suggest that LSG and LRYGB ensure good immunosuppressive maintenance together with significant weight loss and improvement in comorbidities without serious graft rejection or dysfunction. The surgical risk is higher than in the regular BS population.

Complications of Solid Organ Transplantation: Cardiovascular, Neurologic, Renal, and Gastrointestinal

Despite improvements in overall graft function and patient survival rates after solid organ transplantation, complications can lead to significant morbidity and mortality. Cardiovascular complications include heart failure, arrhythmias leading to sudden death, hypertension, left ventricular hypertrophy, and allograft vasculopathy in heart transplantation. Neurologic complications include stroke, posterior reversible encephalopathy syndrome, infections, neuromuscular disease, seizure disorders, and neoplastic disease. Acute kidney injury occurs from immunosuppression with calcineurin inhibitors or as a result of graft failure after kidney transplantation. Gastrointestinal complications include infections, malignancy, mucosal ulceration, perforation, biliary tract disease, pancreatitis, and diverticular disease. Immunosuppression can predispose to infections and malignancy.

The Role of Bariatric Surgery in Abdominal Organ Transplantation-the Next Big Challenge?

Obesity is linked to inferior transplant outcome. Bariatric surgery (BS) is an established treatment of morbid obesity. We provide an overview on BS in the field of kidney (KT) and liver transplantation (LT). In end-stage renal disease (ESRD) and KT patients, BS seems safe and feasible. Complication rates were slightly higher compared to the non-transplant population, whereas weight loss and improvement of comorbidities were comparable. Sleeve gastrectomy (SG) was the preferred procedure before KT and superior to gastric bypass (GB) in regard to mortality and morbidity. If conducted after KT, both procedures showed comparable results. BS before LT was associated with high complication rates, in particular after GB. Albeit distinct complications, SG conducted after LT showed the best results. Immunosuppression (IS) changes after BS were rare.

Bariatric Surgery and Kidney-Related Outcomes

The prevalence of severe obesity in both the general and the chronic kidney disease (CKD) populations continues to rise, with more than one-fifth of CKD patients in the United States having a body mass index of ≥35 kg/m². Severe obesity has significant renal consequences, including increased risk of end-stage renal disease (ESRD) and nephrolithiasis. Bariatric surgery represents an effective method for achieving sustained weight loss, and evidence from randomized controlled trials suggests that bariatric surgery is also effective in improving blood pressure, reducing hyperglycemia, and even inducing diabetes remission. There is also observational evidence suggesting that bariatric surgery may diminish the long-term risk of kidney function decline and ESRD. Bariatric surgery appears to be relatively safe in patients with CKD, with postoperative complications only slightly higher than in the general bariatric surgery population. The use of bariatric surgery in patients with CKD might help prevent progression to ESRD or enable selected ESRD patients with severe obesity to become candidates for kidney transplantation. However, there are also renal risks in bariatric surgery, namely, acute kidney injury, nephrolithiasis, and, in rare cases, oxalate nephropathy, particularly in types of surgery involving higher degrees of malabsorption. Although bariatric surgery may improve long-term kidney outcomes, this potential benefit remains unproved and must be balanced with potential adverse events.

Successful Management of New-Onset Diabetes Mellitus and Obesity With the Use of Laparoscopic Sleeve Gastrectomy After Kidney Transplantation-A Case Report

In kidney transplantation, obesity is associated with poorer graft survival and patient survival. Bariatric surgery may provide benefit for these patients, not only by inducing weight loss, but also via reduction of diabetes. We report a case of morbid obesity, poorly controlled new-onset diabetes mellitus, and gout after kidney transplantation that was treated with laparoscopic sleeve gastrectomy 3 years after kidney transplantation. After 1 year of follow-up, 76% excessive body weight loss was attained. No complications were noted. The operation also provided total remission of diabetes and gout as well as good graft survival. Based on our experience, laparoscopic sleeve gastrectomy may be a feasible treatment for obese patients after renal transplantation to help resolve obesity and control new-onset diabetes. However, the timing of operation and the long-term potential for graft and patient survivals with this operation require further study.

Consequences of Recipient Obesity on Postoperative Outcomes in a Renal Transplant: A Systematic Review and Meta-Analysis

OBJECTIVES

The prevalence of obesity is increasing rapidly and globally, yet systemic reviews on this topic are scarce. Our meta-analysis and systemic review aimed to assess how obesity affects 5 postoperative outcomes: biopsy-proven acute rejection, patient death, allograft loss, type 2 diabetes mellitus after transplant, and delayed graft function.

MATERIALS AND METHODS

We evaluated peer-reviewed literature from 22 medical databases. Studies were included if they were conducted in accordance with the Meta-analysis of Observational Studies in Epidemiology criteria, only examined postoperative outcomes in adult patients, only examined the relation between recipient obesity at time of transplant and our 5 postoperative outcomes, and had a minimum score of > 5 stars on the Newcastle-Ottawa scale for nonrandomized studies. Reliable conclusions were ensured by having our studies examined against 2 internationally known scoring systems. Obesity was defined in accordance with the World Health Organization as having a body mass index of > 30 kg/m(2). All obese recipients were compared versus "healthy" recipients (body mass index of 18.5-24.9 kg/m(2)). Hazard ratios were calculated for biopsy-proven acute rejection, patient death, allograft loss, and type 2 diabetes mellitus after transplant. An odds ratio was calculated for delayed graft function.

RESULTS

We assessed 21 retrospective observational studies in our meta-analysis (N = 241 381 patients). In obese transplant recipients, hazard ratios were 1.51 (95% confidence interval, 1.24-1.78) for presence of biopsy-proven acute rejection, 1.19 (95% confidence interval, 1.10-1.31) for patient death, 1.54 (95% confidence interval, 1.38-1.68) for allograft loss, and 1.01 (95% confidence interval, 0.98-1.07) for development of type 2 diabetes mellitus. The odds ratio for delayed graft function was 1.81 (95% confidence interval, 1.51-2.13).

CONCLUSIONS

Our meta-analysis clearly demonstrated greater risks for obese renal transplant recipients and poorer postoperative outcomes with obesity. We confidently recommend renal transplant candidates seek medically supervised weight loss before transplant.

From chronic kidney disease to kidney transplantation: The impact of obesity and its treatment modalities

Obesity is associated with worse short-term outcomes after kidney transplantation but the effect on long-term outcomes is unknown. Although some studies have reported worse outcomes for obese recipients when compared to recipients with a BMI in the normal range, obese recipients who receive a transplant have better outcomes than those who remain wait-listed. Whether transplant candidates should be advised to lose weight before or after transplant has been debated and this is mainly due to the gap in the literature linking pre-transplant weight loss with better outcomes post-transplantation. The issue is further complicated by the use of BMI as a metric of body fat, the obesity paradox in dialysis patients and the different ethical viewpoints of utility versus equity. Measures used to reduce weight loss, including orlistat and bariatric surgery (in particular those with a malabsorptive component), have been associated with enteric hyperoxaluria with consequent risk of nephrolithiasis and oxalate nephropathy. In this review, we discuss the evidence regarding the use of weight loss measures in the kidney transplant candidate and recipient with a view to recommending whether weight loss should be pursued before or after kidney transplantation.

Kidney transplantation in obese patients

The World Health Organization estimated that in 2014, over 600 million people met criteria for obesity. In 2011, over 30% of individuals undergoing kidney transplant had a body mass index (BMI) 35 kg/m² or greater. A number of recent studies have confirmed the relationship between overweight/obesity and important comorbidities in kidney transplant patients. As with non-transplant surgeries, the rate of wound and soft tissue complications are increased following transplant as is the incidence of delayed graft function. These two issues appear to contribute to longer length of stay compared to normal BMI. New onset diabetes after transplant and cardiac outcomes also appear to be increased in the obese population. The impact of obesity on patient survival after kidney transplantation remains controversial, but appears to mirror the impact of extremes of BMI in non-transplant populations. Early experience with (open and laparoscopic) Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy support excellent weight loss (in the range of 50%-60% excess weight lost at 1 year), but experts have recommended the need for further studies. Long term nutrient deficiencies remain a concern but in general, these procedures do not appear to adversely impact absorption of immunosuppressive medications. In this study, we review the literature to arrive at a better understanding of the risks related to renal transplantation among individuals with obesity.

Is bariatric surgery in patients following renal transplantation safe and effective? A best evidence topic

Obesity is common amongst patients with renal transplants (RT). It is associated not only with generic obesity-related complications including diabetes, but also with higher rates of graft rejection and loss. A Best Evidence Topic in surgery was written according to a structured protocol: this is a systematic review of the literature, suitable when the quality of available evidence is low. The question addressed was: is weight-loss surgery (WLS) safe and effective in patients that have had a previous renal transplant? Three prospective case series and one multicentre retrospective study were identified, together reporting on a total of 112 patients who underwent WLS after RT. Eighty-seven patients underwent open WLS and 25 patients underwent laparoscopic operations of which 11 had sleeve gastrectomy and 14 RYGB. Percentage excess weight loss was highly variable between the studies, ranging from an average of 30.8%-75% at 12 months. One graft rejection occurred within 30 days of surgery. All studies were limited by lack of suitable comparison group, short follow-up and heterogeneity in type of bariatric procedure and approach. To date, there is limited evidence to suggest that bariatric surgery is safe and has good short-term outcomes for selected obese patients post-renal transplant.

The impact and treatment of obesity in kidney transplant candidates and recipients

The prevalence of obesity in patients with chronic kidney failure and renal transplant candidates has paralleled the epidemic in the general population. The associated risks of surgical complications and long-term cardiovascular death are significant: most transplant centers consider obesity a relative contra-indication for transplant.

Few studies have focused on conservative weight loss strategies in transplant patients. Studies using administrative databases have found that only a minority of wait-listed patients lose weight and with no apparent benefit to transplant outcomes. The only clinical trial in this area found that an intensive weight-loss program had significantly better success (to listing) than self-directed weight loss. However, only a minority that succeeded with the help of a program (36 %), while the “diet and exercise” group had negligible results.

Laparoscopy has radically shortened the recovery time and decreased the complications associated with bariatric surgery. Reports in transplant patients, who were previously deemed too medically complex, have demonstrated a dramatic and rapid weight loss. The only randomized clinical trial in patients with CKD, which compared sleeve gastrectomy to best medical care clearly favoured the surgical arm for weight loss, but was too small to assess other outcomes. The emerging experience is small but quite promising.

Surgical complications and the effect on immunosuppression remain the chief concerns regarding the use of bariatric surgery in transplant patients. Rigorous prospective studies will be essential to properly evaluate the expected weight loss and the effect on pharmacokinetics of immunosuppressive medications. A routine role for bariatric surgery in transplantation would require evidence of improvements in patient-important outcomes and evidence of safety.

Feasibility and outcomes of laparoscopic sleeve gastrectomy after solid organ transplantation

BACKGROUND

Obesity is common after solid organ transplantation and is associated with worse transplantation-related outcomes. Laparoscopic sleeve gastrectomy (LSG) may be the preferred bariatric operation in transplantation patients over other techniques, such as gastric bypass, given the concerns about medication absorption. However, little is known about LSG outcomes in post-transplantation patients.

OBJECTIVES

We report the outcomes in 10 consecutive patients who underwent solid organ transplantation followed by LSG.

SETTING

An academic medical center.

METHODS

Primary outcomes studied were weight loss, perioperative complications, resolution or improvement of obesity-related co-morbidities, and markers of graft function following LSG.

RESULTS

The types of transplantation before LSG were as follows: liver = 5, kidney = 4, and heart = 1. Mean body mass index (BMI) at LSG was 44.7 ± 1.7 kg/m(2). All patients had hypertension, and 6 had type 2 diabetes. Perioperative complications occurred in 2 patients, and there were no deaths. Excess weight loss at 12 and 24 months after LSG was 45.7% and 42.5%, respectively. At 1 year after LSG, there was a significant reduction in the number of antihypertensive medications (2.4 to 1.5; P = .02). Three patients achieved complete remission of type 2 diabetes, and the other 3 significantly reduced their dosages of insulin. Graft function remained preserved in liver transplantation patients; left ventricular ejection fraction (LVEF) increased by 10% in the heart transplantation subject, and the estimated glomerular filtration rate (eGFR) increased significantly in kidney transplantation patients (53 ± 3 to 82 ± 3 mL/min; P = .03).

CONCLUSIONS

We concluded that LSG, in selected patients with severe obesity after solid organ transplantation, results in significant weight loss, improvement or resolution of obesity-related conditions, and preservation or improvement of graft function. Larger studies are needed to determine tolerability standards.