Diabetes mellitus, and not obesity, is associated with lower survival following liver transplantation

Survival benefit of liver transplantation utilizing marginal donor organ according to ABO blood type

The current liver transplantation (LT) allocation policy focuses on the MELD scores, often overlooking factors like blood type and survival benefits. Understanding blood types' impact on survival benefits is crucial for optimizing the MELD 3.0 classification. This study used the United Network for Organ Sharing national registry database (2003-2020) to identify LT characteristics per ABO blood type and to determine the optimal MELD 3.0 scores for each blood type, based on survival benefits. The study included candidates of LT aged 18 years or older listed for LT (total N=150,815; A: 56,546, AB: 5841, B: 18,500, O: 69,928). Among these, 87,409 individuals (58.0%) underwent LT (A:32,156, AB: 4,362, B: 11,786, O: 39,105). Higher transplantation rates were observed in AB and B groups, with lower median MELD 3.0 scores at transplantation (AB: 21, B: 24 vs. A/O: 26, p <0.01) and shorter waiting times (AB: 101 d, B:172 d vs. A: 211 d, O: 201 d, p <0.01). A preference for donation after cardiac death (DCD) was seen in A and O recipients. Survival benefit analysis indicated that B blood type required higher MELD 3.0 scores for transplantation than A and O (donation after brain death transplantation: ≥15 in B vs. ≥11 in A/O; DCD transplantation: ≥21 in B vs. ≥11 in A, ≥15 in O). The study suggests revising the allocation policy to consider blood type for improved post-LT survival. This calls for personalized LT policies, recommending higher MELD 3.0 thresholds, particularly for individuals with type B blood.

Long Term Complications of Immunosuppression Post Liver Transplant

Improvement in immunosuppression has led to a remarkable improvement in short-term and long-term outcomes post-liver transplant (LT). However, with improvements in long-term survival, complications related to immunosuppressive drugs, either directly or indirectly, have also increased. The adverse events could be drug-specific, class-specific, or generic. Calcineurin inhibitors (cyclosporine and tacrolimus) are the backbone of the immunosuppression after LT and the main culprit associated with most of the complications, including renal failure, post-transplant diabetes mellitus (PTDM), and metabolic syndrome. Steroids are also implicated in the development of diabetes, osteoporosis, and metabolic syndrome post-LT. The development of infections and de novo malignancies (DNMs) is a generic effect linked to the overall cumulative immunosuppression. The development of these complications significantly hampers the quality of life and leads to increased morbidity and mortality post-LT. Thus, it is important to minimize the cumulative immunosuppression dose while simultaneously preventing allograft rejection. This review provides up-to-date, comprehensive knowledge of the complications of long-term immunosuppression post-LT along with associated risk factors and strategies to minimize the risk of complications.

Waitlist and posttransplantation outcomes of lean individuals with nonalcoholic fatty liver disease

Lean individuals with nonalcoholic fatty liver disease (NAFLD) represent a subset of patients with a distinct risk factor profile. We assessed the association between body mass index (BMI) on waitlist and postliver transplantation (LT) outcomes among these patients. We retrospectively analyzed the United Network for Organ Sharing data, including adult patients with NAFLD listed for LT between February 27, 2002, and June 30, 2020. We first used competing risk analyses to estimate the association of BMI with waitlist removal due to death or clinical deterioration. We then conducted Kaplan-Meier estimates and Cox regression models to determine the impact of weight change during the waiting list on all-cause mortality and graft failure after LT. Patients with normal weight (BMI 18.5-24.9 kg/m 2 ) suffered higher waitlist removal (adjusted subdistribution hazard ratio 1.26, 95% confidence interval [CI] 1.10-1.43; p = 0.001) compared with patients with obesity class I (BMI 30-34.9 kg/m 2 ). Those who remained at normal weight had higher all-cause mortality (adjusted hazard ratio [aHR] 1.61, 95% CI 1.32-1.96; p  <0.001) and graft failure (aHR 1.57, 95% CI 1.32-1.88; p  <0.001) than patients with stable obesity. Among patients with normal weight, those with the greatest weight increase (BMI gain ≥3 kg/m 2 ) had lower all-cause mortality (aHR 0.55, 95% CI 0.33-0.93; p = 0.03) and graft failure (aHR 0.49, 95% CI 0.30-0.81; p = 0.01) compared with patients with stable weight (BMI change ≤1 kg/m 2 ). Patients with NAFLD with normal weight have increased waitlist removal and those who remained at normal weight during the waitlist period have worse posttransplantation outcomes. Identifying and addressing factors influencing apparent healthy weight prior to LT are crucial to mitigate poor outcomes.

Evaluation of liver transplant candidates with non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is anticipated to become the leading indication for liver transplantation (LT) in the United States in the near future. LT is indicated in patients with NASH-related cirrhosis who have medically refractory hepatic decompensation, synthetic dysfunction, and hepatocellular carcinoma (HCC) meeting certain criteria. The objective of LT evaluation is to determine which patient will derive the most benefit from LT with the least risk, thus maximizing the societal benefits of a limited resource. LT evaluation is a multidisciplinary undertaking involving several specialists, assessment tools, and diagnostic testing. Although the steps involved in LT evaluation are relatively similar across different liver diseases, patients with NASH-related cirrhosis have unique demographic and clinical features that affect transplant outcomes and influence their LT evaluation. LT candidates with NASH should be assessed for metabolic syndrome and obesity, malnutrition and sarcopenia, frailty, and cardiovascular disease. Interventions that treat cardiometabolic co-morbidities and improve patients' nutrition and functionality should be considered in order to improve patient outcomes in the waitlist and after LT.

Multidirectional facets of obesity management in the metabolic syndrome population after liver transplantation

The obesity pandemic has resulted in an increasing demand for liver transplantation and has significantly altered the profile of liver transplant candidates in addition to affecting posttransplantation outcomes. In this review, we discuss a broad range of clinical approaches that warrant attention to provide comprehensive and patient‐centred medical care to liver transplant recipients, and to be prepared to confront the rapidly changing clinical challenges and ensuing dilemmas. Adipose tissue is a complex and metabolically active organ. Visceral fat deposition is a key predictor of overall obesity‐related morbidity and mortality. Limited pharmacological options are available for the treatment of obesity in the liver transplant population. Bariatric surgery may be an alternative in eligible patients. The rapidly increasing prevalence of nonalcoholic fatty liver disease (NAFLD) is a global concern; NAFLD affects both pre‐ and posttransplantation outcomes. Numerous studies have investigated pharmacological and nonpharmacological management of NAFLD and some of these have shown promising results. Liver transplant recipients are constantly exposed to numerous factors that result in intestinal microbiota alterations, which were linked to the development of obesity, diabetes type 2, metabolic syndrome (MS), NAFLD, and hepatocellular cancer. Microbiota modifications with probiotics and prebiotics bring gratifying results in the management of metabolic complications. Fecal microbiota transplantation (FMT) is successfully performed in many medical indications. However, the safety and efficacy profiles of FMT in immunocompromised patients remain unclear. Obesity together with immunosuppressive treatment, may affect the pharmacokinetic and/or pharmacodynamic properties of coadministered medications. Individualized immunosuppressive regimens are recommended following liver transplantation to address possible metabolic concerns. Effective and comprehensive management of metabolic complications is shown to yield multiple beneficial results in the liver transplant population and may bring gratifying results in improving long‐term survival rates.

Hepatogenous Diabetes: A Primer

As liver is one of the primary organs involved in glucose homeostasis, it is not surprising that patients with liver dysfunction in chronic liver disease usually develop impaired glucose tolerance and subsequently overt diabetes later in their natural course. Diabetes that develops after the onset of cirrhosis of liver is usually referred to as hepatogenous diabetes (HD). It is an underrecognized and a hallmark endocrinological event in chronic liver disease. HD is associated with a higher risk of developing hepatic decompensations, such as ascites, variceal bleeding, hepatic encephalopathy, renal dysfunction, refractory ascites, and hepatocellular carcinoma along with reduced survival rates than normoglycemic patients with cirrhosis of liver. It is quite different from type 2 diabetes mellitus with the absence of classical risk factors, dissimilar laboratory profiles, and decreased incidence of microvascular complications. Furthermore, the management of patients with HD is challenging because of altered pharmacokinetics of most antidiabetic drugs and increased risk of hypoglycemia and other adverse effects. Hence, a clear understanding of the epidemiology, pathophysiology, clinical implications, laboratory diagnosis, and management of HD is essential for both hepatologists as well as endocrinologists, which is narrated briefly in this review.

Obesity Management of Liver Transplant Waitlist Candidates and Recipients

Obesity is increasing in prevalence in liver transplant candidates and recipients. The rise in liver transplantation for nonalcoholic steatohepatitis reflects this increase. Management of obesity in liver transplant candidates can be challenging due to the presence of decompensated cirrhosis and sarcopenia. Obesity may increase peritransplant morbidity but does not have an impact on long-term post-transplant survival. Bariatric surgery may be a feasible option in select patients before, during, or after liver transplantation. Use of weight loss drugs and/or endoscopic therapies for obesity management ultimately may play a role in liver transplant patients, but more research is needed to determine safety.

Cardiac and Pulmonary Vascular Risk Stratification in Liver Transplantation

Cardiovascular disease complications are the leading cause of early (short-term) mortality among liver transplant recipients. The increasingly older candidate pool has multiple comorbidities necessitating cardiac and pulmonary vascular disease risk stratification of patients for optimal allocation of scarce donor livers. Arrhythmias, heart failure, stroke, and coronary artery disease are common pretransplant cardiovascular comorbidities and contribute to cardiovascular complications after liver transplant. Valvular heart disease and portopulmonary hypertension present intraoperative challenges during liver transplant surgery. The Cardiovascular Risk in Orthotopic Liver Transplantation score estimates the risk of cardiovascular complications in liver transplant candidates within the first year after transplant.

Donor diabetes mellitus is a risk factor for diminished outcome after liver transplantation: a nationwide retrospective cohort study

With the growing incidence of diabetes mellitus (DM), an increasing number of organ donors with DM can be expected. We sought to investigate the association between donor DM with early post‐transplant outcomes. From a national cohort of adult liver transplant recipients (1996–2016), all recipients transplanted with a liver from a DM donor (n = 69) were matched 1:2 with recipients of livers from non‐DM donors (n = 138). The primary end‐point included early post‐transplant outcome, such as the incidence of primary nonfunction (PNF), hepatic artery thrombosis (HAT), and 90‐day graft survival. Cox regression analysis was used to analyze the impact of donor DM on graft failure. PNF was observed in 5.8% of grafts from DM donors versus 2.9% of non‐DM donor grafts (P = 0.31). Recipients of grafts derived from DM donors had a higher incidence of HAT (8.7% vs. 2.2%, P = 0.03) and decreased 90‐day graft survival (88.4% [70.9–91.1] vs. 96.4% [89.6–97.8], P = 0.03) compared to recipients of grafts from non‐DM donors. The adjusted hazard ratio for donor DM on graft survival was 2.21 (1.08–4.53, P = 0.03). In conclusion, donor DM is associated with diminished outcome early after liver transplantation. The increased incidence of HAT after transplantation of livers from DM donors requires further research.

Changing trends of liver transplantation and mortality from non-alcoholic fatty liver disease

The rising tide of non-alcoholic fatty liver disease (NAFLD) associated with the obesity epidemic is a major international health concern. NAFLD is the leading global cause of liver disease with an estimated prevalence of 25% and is the fastest growing indication for liver transplantation (LT). The presence and severity of liver fibrosis is the only histologic predictor of clinical outcomes in this group. NAFLD poses several challenges in the peri-transplant setting including the management of multiple metabolic co-morbidities, post-transplant obesity and cardiovascular risk. However, post-LT outcomes in well-selected NAFLD patients appear similar to non-NAFLD indications, including in the setting of hepatocellular carcinoma (HCC). The rising prevalence of NAFLD may impact potential liver graft donors, which may in-turn adversely affect post-LT outcomes. This review outlines the current epidemiology, natural history and outcomes of NAFLD with a focus on pre- and post-liver transplant settings.

Early Acute Kidney Injury Associated with Liver Transplantation: A Retrospective Case-Control Study

Background

A retrospective case-control study was carried out to assess the occurrence of acute kidney injury (AKI) in liver transplantation (LT) recipients and its related risk factors.

Material/Methods

The study enrolled 131 patients undergoing LT from December 2017 to June 2019 at Beijing Tsinghua Chang Gung Hospital, China. AKI and its classification were defined according to KDIGO guidelines. We collected patients’ demographic characteristics and perioperative parameters, and identified independent risk factors of AKI by multivariate logistic regression analysis.

Results

We included 122 patients in analysis. AKI occurred in 52 (42.6%) patients (22.1% stage I, 8.2% stage II, and 12.3% stage III). AKI was notably associated with 12 factors: sex, body mass index (BMI), hepatic etiology, MELD score, ascites, prothrombin time (PT), international normalized ratio of prothrombin time (INR), preoperative total bilirubin (TBIL), operative time, total fluid intake, fresh frozen plasma (FFP), and estimated blood loss (EBL) (P<0.05). The factors independently associated with AKI were BMI (adjusted odds ratio: 0.605, 95% confidence interval: 0.425–0.859; P=0.005) and intraoperative FFP infusion (adjusted odds ratio: 0.998, 95% confidence interval: 0.995–1.000; P=0.047). Compared with the non-AKI group, the AKI group showed higher likelihood of renal replacement therapy (RRT), and longer ICU and hospital stays, higher in-hospital mortality, and higher hospitalization costs (P<0.05).

Conclusions

There is a high risk of AKI in patients undergoing LT. BMI and intraoperative FFP infusion are factors independently correlated with AKI. AKI can result in extended hospital stays and higher hospitalization expenses.

Management of metabolic syndrome and cardiovascular risk after liver transplantation

Cardiovascular events are the second most prevalent cause of non-hepatic mortality in liver transplant recipients. The incidence of these events is projected to rise because of the growing prevalence of non-alcoholic steatohepatitis as a transplant indication and the ageing population of liver transplant recipients. Recipients with metabolic syndrome are up to four times more likely to have a cardiovascular event than recipients without, therefore prevention and optimal treatment of the components of metabolic syndrome are key in reducing the risk of these events. Although data on the treatment of metabolic comorbidities specifically in liver transplant recipients are scarce, there is detailed guidance from learned societies that mostly mirrors the guidance for patients at increased cardiovascular risk in the general population. In this Review, we discuss the management of the components of metabolic syndrome following liver transplantation and provide practical stepwise guidance. We also emphasise the need for adequately powered studies for the treatment of metabolic comorbidities in liver transplant recipients.

High prevalence of early atherosclerotic and cardiac damage in patients undergoing liver transplantation: Preliminary results

Liver transplanted patients are at high risk of metabolic syndrome and its complications. We aimed to prospectively evaluate the early onset of cardiovascular alterations in patients submitted to the transplant waiting list. From January 2014 to January 2016, 54 out of 79 patients on the waiting list with decompensated cirrhosis or hepatocellular-carcinoma received the transplant, 50 were followed for 24 months, 2 died post-surgery and 2 were lost to follow-up. A significantly increased prevalence of visceral adiposity (epicardial adipose tissue thickness (p = 0.001) and worsening of carotid damage (p = 0.003) and diastolic dysfunction (E/A p = 0.001) was observed at 6 months after transplant and remained stable at 24 months, corresponding to an increased prevalence of diabetes, metabolic syndrome, hypertension and dyslipidemia. The duration of steroid therapy, withdrawn in the majority of patients at 3 months, did not influence cardiovascular damage. No significant difference in early progression of cardiovascular damage was observed between patients who did or did not receive a graft with steatosis. CONCLUSION: The occurrence of early cardiovascular alterations in the first 6 months after OLT accounts for the reported cardiovascular events in the first years after transplant. In light of these results, new strategies aimed at preventing or delaying cardiovascular alterations should be provided, starting from the first weeks after transplant.

Nonalcoholic Steatohepatitis After Liver Transplantation

Currently, nonalcoholic steatohepatitis (NASH) is the second leading indication for liver transplantation (LT), behind alcohol-related liver disease. After transplant, both recurrent and de novo nonalcoholic fatty liver disease are common; however, recurrence rates of NASH and advanced fibrosis are low. Identification of high-risk groups and optimizing treatment of metabolic comorbidities both before and after LT is paramount to maintaining a healthy allograft, especially with the additional consequences of longterm immunosuppression. In addition, NASH LT recipients are at an increased risk of cardiovascular events and malignancy, and their condition warrants a tailored approach to management. The optimal approach to NASH LT recipients including metabolic comorbidities management, tailored immunosuppression, the role of bariatric surgery, and nutritional and pharmacotherapy of NASH are discussed in this review. Overall, aggressive management of metabolic syndrome after LT via medical and surgical modalities and a minimalist approach to immunosuppression is advised.

Obesity in the Liver Transplant Setting

The obesity epidemic has resulted in an increased prevalence of obesity in liver transplant (LT) candidates and in non-alcoholic fatty liver disease (NAFLD) becoming the fastest growing indication for LT. LT teams will be dealing with obesity in the coming years, and it is necessary for them to recognize some key aspects surrounding the LT in obese patients. Obesity by itself should not be considered a contraindication for LT, but it should make LT teams pay special attention to cardiovascular risk assessment, in order to properly select candidates for LT. Obese patients may be at increased risk of perioperative respiratory and infectious complications, and it is necessary to establish preventive strategies. Data on patient and graft survival after LT are controversial and scarce, especially for long-term outcomes, but morbid obesity may adversely affect these outcomes, particularly in NAFLD. The backbone of obesity treatment should be diet and exercise, whilst being careful not to precipitate or worsen frailty and sarcopenia. Bariatric surgery is an alternative for treatment of obesity, and the ideal timing regarding LT is still unknown. Sleeve gastrectomy is probably the procedure that has the best evidence in LT because it offers a good balance between safety and efficacy.

International Liver Transplantation Consensus Statement on End-stage Liver Disease Due to Nonalcoholic Steatohepatitis and Liver Transplantation

Nonalcoholic steatohepatitis (NASH)-related cirrhosis has become one of the most common indications for liver transplantation (LT), particularly in candidates older than 65 years. Typically, NASH candidates have concurrent obesity, metabolic, and cardiovascular risks, which directly impact patient evaluation and selection, waitlist morbidity and mortality, and eventually posttransplant outcomes. The purpose of these guidelines is to highlight specific features commonly observed in NASH candidates and strategies to optimize pretransplant evaluation and waitlist survival. More specifically, the working group addressed the following clinically relevant questions providing recommendations based on the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) system supported by rigorous systematic reviews and consensus: (1) Is the outcome after LT similar to that of other etiologies of liver disease? (2) Is the natural history of NASH-related cirrhosis different from other etiologies of end-stage liver disease? (3) How should cardiovascular risk be assessed in the candidate for LT? Should the assessment differ from that done in other etiologies? (4) How should comorbidities (hypertension, diabetes, dyslipidemia, obesity, renal dysfunction, etc.) be treated in the candidate for LT? Should treatment and monitoring of these comorbidities differ from that applied in other etiologies? (5) What are the therapeutic strategies recommended to improve the cardiovascular and nutritional status of a NASH patient in the waiting list for LT? (6) Is there any circumstance where obesity should contraindicate LT? (7) What is the optimal time for bariatric surgery: before, during, or after LT? (8) How relevant is donor steatosis for LT in NASH patients?

Association of Pretransplant Renal Function With Liver Graft and Patient Survival After Liver Transplantation in Patients With Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is one of the top 3 indications for liver transplantation (LT) in Western countries. It is unknown whether renal dysfunction at the time of LT has any effect on post-LT outcomes in recipients with NASH. From the United Network for Organ Sharing-Standard Transplant Analysis and Research data set, we identified 4088 NASH recipients who received deceased donor LT. We divided our recipients a priori into 3 categories: group 1 with estimated glomerular filtration rate (eGFR) <30 mL/minute/1.73 m2 at the time of LT and/or received dialysis within 2 weeks preceding LT (n = 937); group 2 with recipients who had eGFR ≥30 mL/minute/1.73 m2 and who did not receive renal replacement therapy prior to LT (n = 2812); and group 3 with recipients who underwent simultaneous liver-kidney transplantation (n = 339). We examined the association of pretransplant renal dysfunction with death with a functioning graft, all-cause mortality, and graft loss using competing risk regression and Cox proportional hazards models. The mean ± standard deviation age of the cohort at baseline was 58 ± 8 years, 55% were male, 80% were Caucasian, and average exception Model for End-Stage Liver Disease score was 24 ± 9. The median follow-up period was 5 years (median, 1816 days; interquartile range, 1090-2723 days). Compared with group 1 recipients, group 2 recipients had 19% reduced trend for risk for death with a functioning graft (subhazard ratio [SHR], 0.81; 95% confidence interval [CI], 0.64-1.02) and similar risk for graft loss (SHR, 1.25; 95% CI, 0.59-2.62), whereas group 3 recipients had similar risk for death with a functioning graft (SHR, 1.23; 95% CI, 0.96-1.57) and graft loss (SHR, 0.18; 95% CI, 0.02-1.37) using an adjusted competing risk regression model. In conclusion, recipients with preserved renal function before LT showed a trend toward lower risk of death with a functioning graft compared with SLKT recipients and those with pretransplant severe renal dysfunction in patients with NASH.

In-hospital outcomes for solid organ transplants according to type 2 diabetes status: An observational, 15-year study in Spain

AIMS

To describe trends and outcomes during admission for solid organ transplant in people with or without type 2 diabetes in Spain, 2001-2015.

METHODS

We used national hospital discharge data to select all hospital admissions for kidney, lung, heart, and liver transplant. We estimated admission rates stratified by type 2 diabetes status. We built Poisson regression models to compare the adjusted time trends in admission rates. We tested in-hospital mortality (IHM) in logistic regression analyses.

RESULTS

We identified 50 964 transplants (16.7% in people with type 2 diabetes): kidney, 30 919; lung, 2810; heart, 3649; liver, 13 586. The overall adjusted incidence rate ratios (95% confidence intervals) of admission in people with type 2 diabetes vs no diabetes were 2.4 (2.32-2.48) for kidney, 1.51 (1.33-1.70) for lung, 2.87 (2.63-3.13) for heart, and 4.16 (3.99-4.33) for liver transplant. In the multivariate analysis, IHM decreased significantly over time for all types of transplant. Type 2 diabetes independently predicted lower IHM during admission only for heart (Odds ratio, OR [95% CI] = 0.62 [0.47-0.81]) and liver transplant (OR [95% CI] = 0.69 [0.58-0.82]).

CONCLUSIONS

Admission rates for solid organ transplant were higher in people with type 2 diabetes than in people without diabetes. Type 2 diabetes was associated with lower in-hospital mortality during admission for heart and liver transplant.

Specific issues concerning the management of patients on the waiting list and after liver transplantation

The present document is a second contribution collecting the recommendations of an expert panel of transplant hepatologists appointed by the Italian Association for the Study of the Liver (AISF) concerning the management of certain aspects of liver transplantation, including: the issue of prompt referral; the management of difficult candidates; malnutrition; living related liver transplants; hepatocellular carcinoma; and the role of direct acting antiviral agents before and after transplantation. The statements on each topic were approved by participants at the AISF Transplant Hepatology Expert Meeting organized by the Permanent Liver Transplant Commission in Mondello on 12-13 May 2017. They are graded according to the GRADE grading system.

Impact of sarcopenic overweight on the outcomes after living donor liver transplantation

Background

The effect of body composition disturbances has been recently in focus. Sarcopenic obesity, a co-occurrence of low muscle mass and high body fat was reportedly predictive of high mortality in patients with cirrhosis. However, the impact of the interacting sarcopenia and overweight on the outcomes after liver transplantation is still unclear.

Methods

We evaluated 200 patients undergoing adult-to-adult living donor liver transplantation at our institution between January 2008 and November 2013 classified according to BMI and psoas muscle index (PMI) on admission to transplant into 4 subgroups; sarcopenic overweight (SO), sarcopenic non-overweight (SN), non-sarcopenic overweight and non-sarcopenic non-overweight (NN). Short-term outcomes and overall post-transplant survival were compared among the four subgroups.

Results

Sarcopenic patients with preoperative low PMI had higher incidence of postoperative bacteremia and major postoperative complications, and poorer overall post-transplant survival than non-sarcopenic patients with normal/high PMI (P<0.001, respectively). Overweight recipients had a significantly higher overall survival (OS) rate than non-overweight patients (P=0.021). SO subgroup (low PMI and BMI ≥25) had statistically indifferent incidence of postoperative bacteremia, major postoperative complications or overall post-transplant survival than other recipients. In contrast, SN subgroup (low PMI and BMI <25) had higher incidence of postoperative bacteremia (P<0.001), major postoperative complications (P<0.001) than the SO subgroup and possessed the poorest OS among the four recipient subgroups (P=0.001).

Conclusions

In living donor liver transplantation, preoperative SO did not confer added significant morbidity or mortality risks than the stand-alone sarcopenia.

Cardiovascular mortality among liver transplant recipients with nonalcoholic steatohepatitis in the United States-a retrospective study

Nonalcoholic steatohepatitis (NASH) has become an increasingly important indication for liver transplantation (LT), and there has been a particular concern of excessive cardiovascular-related mortality in this group. Using the United Network for Organ Sharing-Standard Transplant Analysis and Research (UNOS STAR) dataset, we reviewed data on 56,995 adult transplants (January 2002 through June 2013). A total of 3,170 NASH liver-only recipients were identified and were matched with 3,012 non-NASH HCV+ and 3,159 non-NASH HCV- controls [matched 1:1 based on gender, age at LT (±3 years), and MELD score (±3)]. Cox regression analysis revealed significantly lower hazard of all-cause (HR 0.669; P < 0.0001) and cardiovascular-related mortality (HR 0.648; P < 0.0001) in the NASH compared to the non-NASH group after adjusting for diabetes, BMI, and race. Relative to the non-NASH HCV-positive group, NASH group has lower hazard of all-cause (HR 0.539; P < 0.0001) and cardiovascular-related mortality (HR 0.491; P < 0001). A lower hazard of all-cause mortality (HR 0.844; P = 0.0094) was also observed in NASH patients compared to non-NASH HCV-negative group, but cardiovascular mortality was similar (HR 0.892; P = 0.3276). LT recipients with NASH have either lower or similar risk of all-cause and cardiovascular-related mortality compared to its non-NASH counterparts after adjusting for diabetes, BMI, and race.

Liver Transplantation in the Obese Cirrhotic Patient

Despite the rapidly increasing prevalence of obesity in the transplant population, the optimal management of obese liver transplant candidates remains undefined. Setting strict body mass index cutoffs for transplant candidacy remains controversial, with limited data to guide this practice. Body mass index is an imperfect measure of surgical risk in this population, partly due to volume overload and variable visceral adiposity. Weight loss before transplantation may be beneficial, but it remains important to avoid protein calorie malnutrition and sarcopenia. Intensive lifestyle modifications appear to be successful in achieving weight loss, though the durability of these interventions is not known. Pretransplant and intraoperative bariatric surgeries have been performed, but large randomized controlled trials are lacking. Traditional cardiovascular comorbidities are more prevalent in obese individuals and remain the basis for pretransplant cardiovascular evaluation and risk stratification. The recent US liver transplant experience demonstrates comparable patient and graft survival between obese and nonobese liver transplant recipients, but obesity presents important medical and surgical challenges during and after transplant. Specifically, obesity is associated with an increased incidence of wound infections, wound dehiscence, biliary complications and overall infection, and confers a higher risk of posttransplant obesity and metabolic syndrome-related complications. In this review, we examine current practices in the obese liver transplant population, offer recommendations based on the currently available data, and highlight areas where additional research is needed.

Obesity as predictor of postoperative outcomes in liver transplant candidates: Review of the literature and future perspectives

BACKGROUND

Current American and European guidelines consider a pre-transplant BMI ≥40kg/m2 as a relative contraindication for liver transplantation but this recommendation is graded as uncertain and requires further research. Moreover, conflicting results are reported on the predictive value of BMI 30-39.9kg/m2 on post-transplant complication and mortality risk.

AIM

This study analyzed the data of the literature on the effect of all three BMI classes of obesity on postoperative outcomes in liver transplantation.

MATERIALS AND METHODS

A PubMed and Cochrane Library search was conducted from inception to October 2015.

RESULTS

Analysis of the literature demonstrates that discrepancies among studies are mainly either due to limitations of BMI per se, the different BMI cut-offs used to select patients with obesity or reference group and the different outcomes considered. Moreover, the evaluation of visceral adipose tissue and the detrimental effect of muscle mass reduction in presence of obesity are never considered.

CONCLUSIONS

BMI assessment should be used as a preliminary method to evaluate obesity. Subsequently, the assessment of visceral adipose tissue and muscle mass should complete the preoperative evaluation of liver transplant candidates. This innovative approach could represent a new field of research in liver transplantation.

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.

Reduced impact of renal failure on the outcome of patients with alcoholic liver disease undergoing liver transplantation

BACKGROUND & AIMS

Pretransplant renal failure is commonly reported to be a poor prognostic indicator affecting survival after liver transplantation (LT). However, whether the impact of renal failure on patient outcome varies according to the aetiology of the underlying liver disease is largely unknown.

METHODS

We investigated the association between renal failure at the time of LT and patient outcome in patients with alcoholic liver disease (ALD) (n = 6920), non-alcoholic steatohepatitis (NASH) (n = 2956) and hepatitis C (HCV) (n = 14 922) using the United Network for Organ Sharing (UNOS) database between February 2002 and December 2013. A total of 24 798 transplant recipients were included.

RESULTS

The presence of renal failure was more frequently seen in patients with ALD (23.95%) and NASH (23.27%) compared to patients with HCV (19.38%) (P < 0.001). In multivariate analysis, renal failure was an independent predictor of poor survival. Renal failure showed detrimental effect on patient survival in the overall series (HR = 1.466, P < 0.0001). Importantly, the impact of renal failure was less marked in patients with ALD (HR = 1.31, P < 0.0001) than in patients with NASH (HR = 1.73, P < 0.0001) or HCV (HR = 1.52, P < 0.0001). Despite a higher model for end-stage liver disease (MELD) score at the time of LT, ALD patients with renal failure had better long-term prognosis than non-ALD patients.

CONCLUSIONS

Renal failure at the time of LT conferred a lower patient and graft survival post-LT. However, renal failure has less impact on the outcome of patients with ALD than that of patients with non-alcoholic liver disease after LT.

Cardiovascular risk after orthotopic liver transplantation, a review of the literature and preliminary results of a prospective study

Improved surgical techniques and greater efficacy of new anti-rejection drugs have significantly improved the survival of patients undergoing orthotopic liver transplantation (OLT). This has led to an increased incidence of metabolic disorders as well as cardiovascular and cerebrovascular diseases as causes of morbidity and mortality in OLT patients. In the last decade, several studies have examined which predisposing factors lead to increased cardiovascular risk (i.e., age, ethnicity, diabetes, NASH, atrial fibrillation, and some echocardiographic parameters) as well as which factors after OLT (i.e., weight gain, metabolic syndrome, immunosuppressive therapy, and renal failure) are linked to increased cardiovascular mortality. However, currently, there are no available data that evaluate the development of atherosclerotic damage after OLT. The awareness of high cardiovascular risk after OLT has not only lead to the definition of new but generally not accepted screening of high risk patients before transplantation, but also to the need for careful patient follow up and treatment to control metabolic and cardiovascular pathologies after transplant. Prospective studies are needed to better define the predisposing factors for recurrence and de novo occurrence of metabolic alterations responsible for cardiovascular damage after OLT. Moreover, such studies will help to identify the timing of disease progression and damage, which in turn may help to prevent morbidity and mortality for cardiovascular diseases. Our preliminary results show early occurrence of atherosclerotic damage, which is already present a few weeks following OLT, suggesting that specific, patient-tailored therapies should be started immediately post OLT.

Factors Associated With Major Adverse Cardiovascular Events After Liver Transplantation Among a National Sample

Assessment of major adverse cardiovascular events (MACE) after liver transplantation (LT) has been limited by the lack of a multicenter study with detailed clinical information. An integrated database linking information from the University HealthSystem Consortium and the Organ Procurement and Transplant Network was analyzed using multivariate Poisson regression to assess factors associated with 30- and 90-day MACE after LT (February 2002 to December 2012). MACE was defined as myocardial infarction (MI), heart failure (HF), atrial fibrillation (AF), cardiac arrest, pulmonary embolism, and/or stroke. Of 32 810 recipients, MACE hospitalizations occurred in 8% and 11% of patients at 30 and 90 days, respectively. Recipients with MACE were older and more likely to have a history of nonalcoholic steatohepatitis (NASH), alcoholic cirrhosis, MI, HF, stroke, AF and pulmonary and chronic renal disease than those without MACE. In multivariable analysis, age >65 years (incidence rate ratio [IRR] 2.8, 95% confidence interval [95% CI] 1.8-4.4), alcoholic cirrhosis (IRR 1.6, 95% CI 1.2-2.2), NASH (IRR 1.6, 95% CI 1.1-2.4), pre-LT creatinine (IRR 1.1, 95% CI 1.04-1.2), baseline AF (IRR 6.9, 95% CI 5.0-9.6) and stroke (IRR 6.3, 95% CI 1.6-25.4) were independently associated with MACE. MACE was associated with lower 1-year survival after LT (79% vs. 88%, p < 0.0001). In a national database, MACE occurred in 11% of LT recipients and had a negative impact on survival. Pre-LT AF and stroke substantially increase the risk of MACE, highlighting potentially high-risk LT candidates.

Impact of Recipient and Donor Obesity Match on the Outcomes of Liver Transplantation: All Matches Are Not Perfect

There is a paucity of literature examining recipient-donor obesity matching on liver transplantation outcomes. The United Network for Organ Sharing database was queried for first-time recipients of liver transplant whose age was ≥18 between January 2003 and September 2013. Outcomes including patient and graft survival at 30 days, 1 year, and 5 years and overall, liver retransplantation, and length of stay were compared between nonobese recipients receiving a graft from nonobese donors and obese recipient-obese donor, obese recipient-nonobese donor, and nonobese recipient-obese donor pairs. 51,556 LT recipients were identified, including 34,217 (66%) nonobese and 17,339 (34%) obese recipients. The proportions of patients receiving an allograft from an obese donor were 24% and 29%, respectively, among nonobese and obese recipients. Graft loss (HR: 1.27; 95% CI: 1.09–1.46; p = 0.002) and mortality (HR: 1.38; 95% CI: 1.16–1.65; p < 0.001) at 30 days were increased in the obese recipient-obese donor pair. However, 1-year graft (HR: 0.83; 95% CI: 0.74–0.93; p = 0.002) and patient (HR: 0.84; 95% CI: 0.74–0.95; p = 0.007) survival and overall patient (HR: 0.93; 95% CI: 0.86–1.00; p = 0.042) survival were favorable. There is evidence of recipient and donor obesity disadvantage early, but survival curves demonstrate improved long-term outcomes. It is important to consider obesity in the donor-recipient match.

Impact of obesity and diabetes on waitlist survival, probability of liver transplantation and post-transplant survival among chronic hepatitis C virus patients

BACKGROUND & AIMS

The rising prevalence of obesity and diabetes mellitus (DM) among hepatitis C virus (HCV) patients contributes to concurrent nonalcoholic fatty liver disease (NAFLD). We aim to evaluate the impact of concurrent obesity or DM on waitlist survival and probability of liver transplantation (LT) among adults with chronic HCV awaiting LT.

METHODS

Using 2003-2013 United Network for Organ Sharing data, we evaluated the impact of obesity and DM among adults with chronic HCV awaiting LT: non-obese, non-DM vs. obese, non-DM (obese) vs. non-obese, DM (DM) vs. obese and DM. Overall, LT waitlist survival and probability of receiving LT were evaluated using Kaplan-Meier and multivariate logistic regression models.

RESULTS

From 2003-2013, there were 43 478 new LT waitlist registrants with chronic HCV (21.0% with HCC, 79% without HCC). Obesity was associated with lower probability of receiving LT (OR, 0.91; 95% CI, 0.85-0.97; P < 0.01), and lower probability of waitlist mortality (OR, 0.80; 95% CI, 0.72-0.89; P < 0.001) when compared to non-obese patients. DM among HCV patients did not impact probability of waitlist survival or receiving LT. When evaluating post-LT survival, compared to non-obese, non-DM patients, obese HCV patients had significantly lower post-LT mortality (HR 0.86; 95%CI, 0.81-0.92; P < 0.001); whereas, HCV patients with DM had significantly higher post-LT mortality (HR, 1.22; 95% CI, 1.12-1.33; P < 0.001).

CONCLUSION

Among adults with chronic HCV awaiting LT in the US, obesity is associated with lower probability of receiving LT, but did not impact waitlist survival. DM among chronic HCV patients did not impact waitlist survival or probability of LT.

Acute kidney injury following liver transplantation: a systematic review of published predictive models

Acute kidney injury is a frequent postoperative complication amongst liver transplant recipients and is associated with increased morbidity and mortality. This systematic review analysed the existing predictive models, in order to solidify current understanding. Articles were selected for inclusion if they described the primary development of a clinical prediction model (either an algorithm or risk score) to predict AKI post liver transplantation. The database search yielded a total of seven studies describing the primary development of a prediction model or risk score for the development of AKI following liver transplantation. The models span thirteen years of clinical research and highlight a gradual change in the definitions of AKI, emphasising the need to employ standardised definitions for subsequent studies. Collectively, the models identify a diverse range of predictive factors with several common trends. They emphasise the impact of preoperative renal dysfunction, liver disease severity and aetiology, metabolic risk factors as well as intraoperative variables including measures of haemodynamic instability and graft quality. Although several of the models address postoperative parameters, their utility in predictive modelling seems to be of questionable relevance. The common risk factors identified within this systematic review provide a minimum list of variables, which future studies should address. Research in this area would benefit from prospective, multi-site studies with larger cohorts as well as the subsequent internal and external validation of predictive models. Ultimately, the ability to identify patients at high risk of post-transplant AKI may enable early intervention and perhaps prevention.

Profile of Gut Microbiota Associated With the Presence of Hepatocellular Cancer in Patients With Liver Cirrhosis

BACKGROUND

Changes within the gut microbiota contribute to the progression of chronic liver diseases. According to the results of several studies performed in animal models, gut dysbiosis plays an important role in hepatocarcinogenesis. The aim of this study was to explore the characteristics of gut microbiota associated with the presence of hepatocellular cancer (HCC) in patients with cirrhosis of the liver undergoing liver transplantation.

METHODS

A total of 15 patients with HCC and 15 non-HCC patients matched according to etiology of cirrhosis and Model for End-Stage Liver Disease (MELD) scores who underwent liver transplantations between 2012 and 2014 were included. Analysis of their gut microbial profile was based on prospectively collected stool samples from the pretransplant period.

RESULTS

Patients with and without HCC were similar with respect to age (P = .506), sex (P = .700), hepatitis C virus (P > .999) and hepatitis B virus (P = .715) infection status, alcoholic liver disease (P > .999), and MELD score (P = .337). Notably, the presence of HCC was associated with significantly increased fecal counts of Escherichia coli (P = .025). Prediction of HCC presence based on E coli counts was associated with the area under the receiver-operating curve of 0.742 (95% confidence interval, 0.564-0.920), with the optimal cutoff on the level of 17.728 (natural logarithm of colony-forming units per 1 g of feces). Sensitivity and specificity rates for the established cutoff were 66.7% and 73.3%, respectively.

CONCLUSIONS

The profile of gut microbiota associated with the presence of HCC in cirrhotic patients is characterized by increased fecal counts of E coli. Therefore, intestinal overgrowth of E coli may contribute to the process of hepatocarcinogenesis.

Liver Transplantation for Alcoholic and Nonalcoholic Fatty Liver Disease: Pretransplant Selection and Posttransplant Management

Alcoholic fatty liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are common causes of chronic liver disease throughout the world. Although they have similar histologic features, a diagnosis of NAFLD requires the absence of significant alcohol use. ALD is seen commonly in patients with a long-standing history of excessive alcohol use, whereas NAFLD is encountered commonly in patients who have developed complications of obesity, such as insulin resistance, hypertension, and dyslipidemia. Lifestyle contributes to the development and progression of both diseases. Although alcohol abstinence can cause regression of ALD, and weight loss can cause regression of NAFLD, many patients with these diseases develop cirrhosis. ALD and NAFLD account for nearly 30% of liver transplants performed in the United States. Patients receiving liver transplants for ALD or NAFLD have similar survival times as patients receiving transplants for other liver disorders. Although ALD and NAFLD recur frequently after liver transplantation, graft loss from disease recurrence after transplantation is uncommon. Cardiovascular disease and de novo malignancy are leading causes of long-term mortality in liver transplant recipients with ALD or NAFLD.

Additive impact of pre-liver transplant metabolic factors on survival post-liver transplant

BACKGROUND AND AIM

Diabetes at time of liver transplantation is associated with reduced post-transplant survival. We aimed to assess whether additional metabolic conditions such as obesity or hypertension had additive prognostic impact on post-transplantation survival.

METHODS

A multi-center cohort study of 617 adult subjects undergoing liver transplantation between 2003 and 2009 has been used. Dry body mass index was calculated following adjustment for ascites.

RESULTS

After a median follow-up of 5.8 years (range 0-10.5), 112 (18.2%) patients died. Diabetes was associated with reduced post-transplant survival (hazard ratio 1.89, 95% confidence interval [CI] 1.25-2.86, P = 0.003), whereas obesity, hypertension, dyslipidemia, and the metabolic syndrome itself were not (P > 0.3 for all). Patients with concomitant diabetes and obesity had lower survival (adjusted Hazard Ratio [aHR] 2.40, 95%CI 1.32-4.38, P = 0.004), whereas obese non-diabetic patients or diabetic non-obese patients had similar survival compared with non-diabetic, non-obese individuals. The presence of hypertension or dyslipidemia did not impact on survival in patients with diabetes (P > 0.1 for both). Obese diabetic patients had longer intensive care and hospital stays than non-obese diabetic or obese, non-diabetic patients (P < 0.05). The impact of concomitant obesity and diabetes on survival was greater in subjects aged 50+ years (52.6% 5-year survival, aHR 3.04, 95% CI 1.54-5.98) or those transplanted with hepatocellular carcinoma (34.1% 5-year survival, aHR 3.35, 95% CI 1.31-5.57). Diabetes without obesity was not associated with an increased mortality rate in these sub-groups.

CONCLUSIONS

Concomitant diabetes and obesity but not each condition in the absence of the other is associated with reduced post-liver transplant survival. The impact of diabetes and obesity is greater in older patients and those with hepatocellular carcinoma.

Pre-existing diabetes and risks of morbidity and mortality after liver transplantation: A nationwide database study in an Asian population

BACKGROUND

Whether diabetes mellitus (DM) is associated with a higher risk of perioperative mortality and mortality after liver transplantation (LTx) remains unclear.

METHODS

We compared the risk of postoperative mortality and morbidity in DM and non-DM patients undergoing LTx. We enrolled 558 DM patients who underwent LTx from 2000 to 2010.

RESULTS

DM was associated with elevated 90-day risk of post-LTx stroke. Otherwise, the DM cohort did not exhibit significantly higher risks of postoperative morbidities, such as septicemia, pneumonia, and wound infection, than the non-DM cohort. Cox proportional hazards regression model showed that patients with DM with coexisting renal manifestations were at a significantly high risk of 30-day and 90-day postoperative mortality. Further comorbidity stratification analysis showed that DM cohort exhibited higher risk of mortality than the non-DM cohort if the patients had liver cancer, or did not have hypertension, ischemic heart disease, and chronic obstructive pulmonary disease.

CONCLUSION

DM is associated with elevated risk of 90-day post-LTx. Moreover, DM patients with coexisting renal manifestations exhibited an increased postoperative risk of mortality after LTx.