Obesity and organ transplantation: successes, failures, and opportunities

Long-term changes in body weight and serum cholesterol in heart transplant recipients

INTRODUCTION

Long-term changes in weight and blood lipids beyond 12 months after heart transplantation are largely unknown. We quantified changes in weight, body mass index (BMI), blood cholesterol, and triglycerides in heart transplant recipients (HTRs) during the 36 months after transplantation, and we assessed the influence of statin therapy on these outcomes.

METHODS

Retrospective cohort study of adult HTRs, transplanted 1990-2017, in Queensland, Australia. From each patient's medical charts, we extracted weight, total cholesterol, triglycerides, and statin therapy at four time-points: time of transplant (baseline), and 12-, 24-, 36-month post-transplant. Changes in weight and blood lipids were assessed according to baseline BMI.

RESULTS

Among 316 HTRs, 236 (median age 52 years, 83% males) with available information were included. During the 36 months post-transplant, all patients gained weight (83.5-90.5 kg; p < .001), especially those with baseline BMI < 25.0 km/m2 (67.9-76.2 kg; p < .001). Mean blood cholesterol (4.60-4.90 mmol/L; p = .004) and mean blood triglycerides (1.79-2.18 mmol/L; p = .006) also increased significantly in all patients, particularly in those with baseline BMI ≥ 25.0 km/m2 but the differences were not significant (total cholesterol 4.42-5.13 mmol/L; triglycerides 1.76-2.47 mmol/L). Total cholesterol was highest in patients not taking statins, and levels differed significantly (p = .010) according to statin dosing changes during the 36 months post-transplant.

CONCLUSION

Patients demonstrate significant rises in weight and blood lipids in the 36 months after heart transplantation.

Can we HALT obesity following lung transplant? A Dietitian- and Physiotherapy-directed pilot intervention

INTRODUCTION

Unintentional weight gain, overweight and obesity following solid organ transplantation (SOT) are well-established and linked to morbidity and mortality risk factors. No interventional studies aimed at prevention have been undertaken among lung transplant (LTx) recipients. The combination of group education and telephone coaching is effective in the general population but is untested among SOT cohorts.

METHODS

A non-randomised, interventional pilot study was conducted among new LTx recipients. The control group received standard care. In addition to standard care, the intervention involved four group education and four individual, telephone coaching sessions over 12-months. Data collection occurred at 2 weeks, 3- and 12 months post-LTx. Measurements included weight, BMI, fat mass (FM), fat mass index (FMI), fat-free mass (FFM), fat-free mass index (FFMI), waist circumference (WC), visceral adipose tissue (VAT), nutrition knowledge, diet, physical activity, lipid profile, HbA_1C , FEV₁ , six-minute walk distance and patient satisfaction.

RESULTS

Fifteen LTx recipients were recruited into each group. One control participant died 120 days post-LTx, unrelated to the study. There were trends towards lower increases in weight (6.7±7.2kg vs 9.8±11.3kg), BMI (9.6% of baseline vs 13%), FM (19.7% vs 40%), FMI, VAT (7.1% vs 30.8%) and WC (5.5% vs 9.5%), and greater increases in FFM and FFMI (all p>0.05), among the intervention group by 12 months. The intervention was well-accepted by participants.

CONCLUSION

This feasible intervention demonstrated non-significant, but clinically meaningful, favourable weight and body composition trends among LTx recipients over 12 months compared to standard care. Australian New Zealand Clinical Trials Registry (ACTRN12619001606178) This article is protected by copyright. All rights reserved.

Robotic Kidney Transplant: The Modern Era Technical Revolution

Since the mid 20th century, transplantation has been a fast-developing field of contemporary medicine. The technical aspects of transplant operations were developed in the 1950s, with little significant change for >50 y. Those techniques allowed completion of various organ transplants and successful patient outcomes, but they also carried the inherent disadvantages of open surgery, such as postoperative pain, wound complications and infections, and prolonged length of hospital stay. The introduction and adoption of minimally invasive surgical techniques in the early 1990s to various surgical specialties including general, gynecologic, and urologic surgery led to significant improvements in postoperative patient care and outcomes. Organ transplantation, with its precision demanding vascular anastomoses, initially had been considered infeasible to accomplish with conventional laparoscopic devices. The institution of robotic surgical technology in the late 1990s and its subsequent wide utilization in fields of surgery changed its accessibility and acceptance. With the steady camera, 3D views, and multidirectional wrist motions, surgical robotics opened new horizons for technically demanding surgeries such as transplantation to be completed in a minimally invasive fashion. Furthermore, the hope was this technique could find a niche to treat patients who otherwise are not deemed surgical candidates in many fields including transplantation. Here in, robotics in kidney transplantation and its ability to help provide equity through access to transplantation will be discussed.

“You Can’t Manage What You Can’t Measure”: Perspectives of Transplant Recipients on Two Lifestyle Interventions for Weight Management

Previous research suggests that effective lifestyle interventions for solid organ transplant (SOT) recipients must be tailored to address the unique life circumstances of this population. As few studies have investigated this design consideration, this study aimed to explore the perspectives and experiences of SOT recipients after completing a Group Lifestyle Balance™ [GLB]-based intervention incorporating either (a) standard population-based nutrition guidance or (b) nutrigenomics-based nutrition guidance. All active participants in the Nutrigenomics, Overweight/Obesity, and Weight Management-Transplant (NOW-Tx) pilot study were invited to participate. Data were collected through focus groups and individual interviews. Ninety-five percent (n = 18) of the NOW-Tx pilot study participants enrolled in the current study: 15 participated in 3 focus groups; 3 were interviewed individually. Three themes were common to both intervention groups: (1) the post-transplant experience; (2) beneficial program components; (3) suggestions for improvement. A unique theme was identified for the nutrigenomics-based intervention, comprising the sub-themes of intervention-specific advantages, challenges, and problem-solving. The readily available and adaptable GLB curriculum demonstrated both feasibility and acceptability and was aligned with participants’ needs and existing health self-management skills. The addition of nutrigenomics-based guidance to the GLB curriculum may enhance motivation for behaviour change in this patient population.

Effectiveness of Bariatric Surgery in Increasing Kidney Transplant Eligibility in Patients with Kidney Failure Requiring Dialysis

PURPOSE

Severe obesity can increase risk of complications after kidney transplantation. There is a paucity of literature on bariatric surgery outcomes in renal transplant candidates. The objective of this study was to analyze outcomes of bariatric surgery as a weight reduction strategy for patients with kidney failure to enhance eligibility for kidney transplantation.

MATERIALS AND METHODS

We performed a retrospective analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database at a single institution for patients with chronic kidney disease receiving hemodialysis therapy (CKD G5D) undergoing bariatric surgery between 2011 and 2018.

RESULTS

Of 2363 patients who underwent bariatric surgery, 38 (1.6%) had CKD G5D; median age (range) was 49 years (33; 69), 52.6% were female, and mean BMI was 44.2 kg/m². Twenty-four patients underwent laparoscopic Roux-en-Y gastric bypass (LRYGB), and 14 patients underwent laparoscopic sleeve gastrectomy. Seventeen patients (46%, n=37) had a BMI≤35 at 6 months, while 25 patients (75.8%, n=33) achieved a BMI≤35 at 12 months. Of these, 18 patients (47%) were listed for kidney transplant, and 8 patients (21%) received kidney transplant. There was no statistically significant difference between sleeve and LRYGB procedures in patients who reached BMI of 35 at 12 months (P=0.58). Median length of stay was 2.3 days. Thirty-day readmission rate was 2 patients (5.3%), and 2 patients (5.3%) required reoperation (one for bleeding, one for acute recurrent hiatal hernia). No mortality occurred.

CONCLUSION

Laparoscopic bariatric surgery offers effective weight loss for CKD G5D patients to achieve transplant eligibility with acceptable outcomes.

Obesity, transplantation, and bariatric surgery: An evolving solution for a growing epidemic

The increasing obesity epidemic has major implications in the realm of transplantation. Patients with obesity face barriers in access to transplant and unique challenges in perioperative and postoperative outcomes. Because of comorbidities associated with obesity, along with the underlying end-stage organ disease leading to transplant candidacy, these patients may not even be referred for transplant evaluation, much less be waitlisted or actually undergo transplant. However, the use of bariatric surgery in this population can help optimize the transplant candidacy of patients with obesity and end-stage organ disease and improve perioperative and postoperative outcomes. We review the impact of obesity on kidney, liver, and cardiothoracic transplant candidates and recipients and explore potential interventions to address obesity in these populations.

Obesity in kidney transplantation

The prevalence of obesity among patients with chronic kidney disease continues to increase as a reflection of the trend observed in the general population. Factors affecting the access to the waiting list and the transplantability of this specific population will be analysed. From observational studies, kidney transplantation in obese patients carries an increased risk of surgical complications compared to the nonobese population; therefore, many centres have been reluctant to proceed with transplantation, despite this treatment modality confers a survival advantage over dialysis. As a consequence, obese patients continue to face decreased access to the waiting list, with a lower likelihood of being transplanted and higher waiting times when compared to the nonobese candidates. In this review will be described the current strategies for treatment of obesity in different settings (pretransplant, at transplant and post-transplant). Obesity represents a risk factor for surgical complications but not a contraindication for kidney transplantation; outcomes could be greatly improved with its multidisciplinary and multimodal treatment. The modern technology with minimally invasive techniques, mainly using robotic platform, allows a reduction in the surgical complications rate, with graft and patient survival rates comparable to the nonobese counterpart.

Systematic review with meta-analysis: post-operative complications and mortality risk in liver transplant candidates with obesity

BACKGROUND

International guidelines rate class III (morbid) obesity (body mass index [BMI]≥40 kg/m² ) as a relative contraindication for liver transplantation (LT) requiring further research. Moreover, data on the mortality risk in candidates with a BMI: 30-34.9 and 35-39.9 kg/m² (class I and class II obesity, respectively) are weak.

AIM

To compare post-operative complications and mortality risks in all obese candidates vs candidates with a BMI: 18.5-29.9 (normal/overweight) assumed as controls.

METHODS

We searched the Cochrane library, PubMed, Scopus, Web-of-Science and article reference lists, restricted to the English language, and selected cohort studies analysing the following outcomes: all-causes mortality (at 30 days, 1-2-3-5 years), post-operative and cardiopulmonary complications, hospital and intensive care unit (ICU) length of stay. Two reviewers independently extracted the studies data and a third one resolved discrepancies.

RESULTS

Twenty-four studies comprising 132 162 patients met the inclusion criteria. As compared to controls, mortality risk was increased at all time-periods (except at 3 years) for a BMI≥40, at 30 days for a BMI: 30-34.9 and in none of the considered time-periods for a BMI: 35-39.9. Post-operative complications were significantly higher for a BMI>30 and 30-34.9. Due to the shortage/absence of data, we evaluated cardiopulmonary complications, hospital and ICU length of stay only in the BMI≥30 category. In these patients, only cardiopulmonary complications were increased as compared to controls.

CONCLUSIONS

Morbid obesity has an impact on patients' survival after LT. However, since even a BMI>30 increases post-transplant complications, new strategies should be included in the LT programme to favour weight loss in all obese candidates.

Evolution of body weight parameters up to 3 years after solid organ transplantation: The prospective Swiss Transplant Cohort Study

Obesity and weight gain are serious concerns after solid organ transplantation (Tx); however, no unbiased comparison regarding body weight parameter evolution across organ groups has yet been performed. Using data from the prospective nationwide Swiss Transplant Cohort Study, we compared the evolution of weight parameters up to 3 years post-Tx in 1359 adult kidney (58.3%), liver (21.7%), lung (11.6%), and heart (8.4%) recipients transplanted between May 2008 and May 2012. Changes in mean weight and body mass index (BMI) category were compared to reference values from 6 months post-Tx. At 3 years post-Tx, compared to other organ groups, liver Tx recipients showed the greatest weight gain (mean 4.8±10.4 kg), 57.4% gained >5% body weight, and they had the highest incidence of obesity (38.1%). After 3 years, based on their BMI categories at 6 months, normal weight and obese liver Tx patients, as well as underweight kidney, lung and heart Tx patients had the highest weight gains. Judged against international Tx patient data, the majority of our Swiss Tx recipients' experienced lower post-Tx weight gain. However, our findings show weight gain pattern differences, both within and across organ Tx groups that call for preventive measures.

Obesity-Associated Adipose Tissue Inflammation and Transplantation

Obesity is often associated with the development of adipose tissue (AT) inflammation, resulting in metabolic dysfunction and an increased risk for developing type 2 diabetes. It is also associated with multiple chronic diseases, including cardiovascular, liver, and kidney disease, and thus can contribute to organ failure. Several studies have investigated whether there is a correlation between obesity and outcomes in transplantation, but there is currently very limited information on the specific role of AT inflammation in the rejection process or on the overall function of the transplanted organ. Here, we provide a brief review of the current understanding of the cellular mechanisms that control obesity-associated AT inflammation and summarize knowledge about how obesity affects clinical outcomes following solid organ or hematopoietic stem cell transplantation. We also highlight opportunities for more research to better understand how obesity affects outcomes of transplantation.

Post-Transjugular Intrahepatic Portosystemic Shunt Follow-Up and Management in the VIATORR Era

The transjugular intrahepatic portosystemic shunt (TIPS) is a non-selective portosystemic shunt created using endovascular techniques. The first TIPS was performed in Germany in 1988. The VIATORR self-expandable PTFE covered stent-graft (WL Gore, Flagstaff AZ) was approved by the FDA for a TIPS application in December of 2004. This stent-graft offers excellent shunt patency rates and it is possible that it has a beneficial effect on patient survival. Patient surveillance and post-procedural management have changed after the introduction of this stent-graft. This article presents the current management strategies that are followed at our Institution for patients who have undergone a TIPS procedure with a VIATORR stent graft including imaging follow-up, management of encephalopathy, medical management and nutritional aspects.

Postoperative weight gain during the first year after kidney, liver, heart, and lung transplant: a prospective study

CONTEXT

Studies of all types of organ transplant recipients have suggested that weight gain, expressed as an increase in body mass index (BMI), after transplant is common.

OBJECTIVES

To describe weight gain during the first year after transplant and to determine risk factors associated with weight gain with particular attention to type of transplant.

DESIGN, SETTING, AND PARTICIPANTS

A prospective study of 502 consecutive organ transplant recipients (261 kidney, 73 liver, 29 heart, 139 lung) to identify patterns of BMI change. Measurements were made during regular outpatient clinical visits at 2, 6, and 12 months after transplant. Data were retrieved from patients' charts and correlated with maintenance corticosteroid doses.

RESULTS

Overall, mean BMI (SD; range) was 23.9 (4.5; 13.6-44.1) at 2 months and increased to 25.4 (4.0; 13.0-42.2) by the end of the first postoperative year. BMI levels organized by World Health Organization categories showed a trend toward overweight/obesity in kidney (53.4%), liver (51.5%), heart (51.7%), and lung (33.1%) patients by 12 months after transplant. BMI changed significantly (P= .05) for all organ types and between all assessment points, except in kidney recipients. Maintenance corticosteroid doses were not a predictor of BMI at 12 months after transplant for most patients.

CONCLUSIONS

Weight gain was common among patients undergoing kidney, liver, heart, and lung transplant; however, many showed BMI values close to normality at the end of the first year after transplant. In most cases, increased BMI levels were related to obesity before transplant and not to maintenance corticosteroid therapy.

Nutrition in liver transplantation: too little or too much?

PURPOSE OF REVIEW

The purpose of this study was to review the most recent findings on approaches to managing the obesity and muscle wasting that are found in patients before and after liver transplantation.

RECENT FINDINGS

A number of articles have contributed to the accumulating evidence that morbid obesity is not an absolute contraindication to liver transplantation with survival outcomes similar across BMI groups. Obesity is, however, a risk factor for early post-transplant complications and obesity-related comorbidities markedly increase this risk. Very limited data are as yet available, dietary, or otherwise, related to amelioration of these comorbidities and evidence that weight loss leads to improved outcomes in obese patients is lacking. Abdominal computed tomography imaging is increasingly being used to identify muscle wasting, and poorer post-transplant survival is seen in patients with significant muscle wasting. This modality has confirmed the persistence of depleted muscle stores after transplant extending well beyond 1 year. Coupled with this is a high incidence of weight gain and metabolic syndrome and the associated risks. Although dietary intervention and exercise are considered possible approaches to address these issues, work in these areas so far is sparse.

SUMMARY

An urgent need exists for interventional studies on the basis of nutrition and/or exercise to address the challenges presented by both obesity and muscle wasting, which likely coexist in many patients in both the pretransplant and the post-transplant periods.

Body mass index and outcome in renal transplant recipients: a systematic review and meta-analysis

BACKGROUND

Whether overweight or obese end stage renal disease (ESRD) patients are suitable for renal transplantation (RT) is often debated. The objective of this review and meta-analysis was to systematically investigate the outcome of low versus high BMI recipients after RT.

METHODS

Comprehensive searches were conducted in MEDLINE OvidSP, Web of Science, Google Scholar, Embase, and CENTRAL (the Cochrane Library 2014, issue 8). We reviewed four major guidelines that are available regarding (potential) RT recipients. The methodology was in accordance with the Cochrane Handbook for Systematic Reviews of Interventions and written based on the PRISMA statement. The quality assessment of studies was performed by using the GRADE tool. A meta-analysis was performed using Review Manager 5.3. Random-effects models were used.

RESULTS

After identifying 5,526 studies addressing this topic, 56 studies were included. We extracted data for 37 outcome measures (including data of more than 209,000 RT recipients), of which 26 could be meta-analysed. The following outcome measures demonstrated significant differences in favour of low BMI (<30) recipients: mortality (RR = 1.52), delayed graft function (RR = 1.52), acute rejection (RR = 1.17), 1-, 2-, and 3-year graft survival (RR = 0.97, 0.95, and 0.97), 1-, 2-, and 3-year patient survival (RR = 0.99, 0.99, and 0.99), wound infection and dehiscence (RR = 3.13 and 4.85), NODAT (RR = 2.24), length of hospital stay (2.31 days), operation duration (0.77 hours), hypertension (RR = 1.35), and incisional hernia (RR = 2.72). However, patient survival expressed in hazard ratios was in significant favour of high BMI recipients. Differences in other outcome parameters were not significant.

CONCLUSIONS

Several of the pooled outcome measurements show significant benefits for 'low' BMI (<30) recipients. Therefore, we postulate that ESRD patients with a BMI >30 preferably should lose weight prior to RT. If this cannot be achieved with common measures, in morbidly obese RT candidates, bariatric surgery could be considered.

Medical management of patients after bariatric surgery: Principles and guidelines

Obesity is a major and growing health care concern. Large epidemiologic studies that evaluated the relationship between obesity and mortality, observed that a higher body-mass index (BMI) is associated with increased rate of death from several causes, among them cardiovascular disease; which is particularly true for those with morbid obesity. Being overweight was also associated with decreased survival in several studies. Unfortunately, obese subjects are often exposed to public disapproval because of their fatness which significantly affects their psychosocial behavior. All obese patients (BMI ≥ 30 kg/m²) should receive counseling on diet, lifestyle, exercise and goals for weight management. Individuals with BMI ≥ 40 kg/m² and those with BMI > 35 kg/m² with obesity-related comorbidities; who failed diet, exercise, and drug therapy, should be considered for bariatric surgery. In current review article, we will shed light on important medical principles that each surgeon/gastroenterologist needs to know about bariatric surgical procedure, with special concern to the early post operative period. Additionally, we will explain the common complications that usually follow bariatric surgery and elucidate medical guidelines in their management. For the first 24 h after the bariatric surgery, the postoperative priorities include pain management, leakage, nausea and vomiting, intravenous fluid management, pulmonary hygiene, and ambulation. Patients maintain a low calorie liquid diet for the first few postoperative days that is gradually changed to soft solid food diet within two or three weeks following the bariatric surgery. Later, patients should be monitored for postoperative complications. Hypertension, diabetes, dumping syndrome, gastrointestinal and psychosomatic disorders are among the most important medical conditions discussed in this review.