Graft Regeneration and Functional Recovery in Patients with Early Allograft Dysfunction After Living-Donor Liver Transplantation

Early allograft dysfunction after living donor liver transplantation-current concepts and future directions

Early allograft dysfunction (EAD) after liver transplantation is a significant clinical problem that negatively impacts graft and patient outcomes. The rising incidence of EAD and what it means concerning living donor liver transplantation (LDLT) is an area of great interest. However, EAD after LDLT is a complex research topic yet to be reviewed comprehensively. Most of the literature on EAD is based on experience in deceased donor liver transplantation, and limited information is available in the context of LDLT. Thus, in this review, we present an overview of EAD after LDLT and have attempted to present balanced points of view on all its aspects, such as definitions, pathogenesis, risk factors, predictive markers, and management. The review aims to broadly overview the nature and extent of ongoing research evidence on this complex topic and inform practice in the field by identifying key concepts and knowledge gaps and highlighting areas that require further inquiry.

Associations of sarcopenia with graft failure and mortality in patients undergoing living donor liver transplantation

Recent studies have reported that sarcopenia influences morbidity and mortality in surgical patients. However, few studies have investigated the associations of sarcopenia with short-term and long-term graft failure in recipients after living donor liver transplantation (LDLT). In this study, we investigated the associations between sarcopenia and graft failure/mortality in patients undergoing LDLT. We retrospectively examined 2816 recipients who underwent LDLT between January 2008 and January 2018. Cox regression analysis was performed to evaluate the associations between sarcopenia and graft failure/mortality in recipients at 60 days, 180 days, and 1 year and overall. Sarcopenia in the recipient was significantly associated with 60-day graft failure (adjusted hazard ratio [HR], 1.98; 95% confidence interval [CI], 1.09-3.61; p = 0.03), 180-day graft failure (HR, 1.85; 95% CI, 1.19-2.88; p = 0.01), 1-year graft failure (HR, 1.45; 95% CI, 1.01-2.17; p = 0.05), and overall graft failure (HR, 1.42; 95% CI, 1.08-1.87; p = 0.01). In addition, recipient sarcopenia was associated with 180-day mortality (HR, 1.88; 95% CI, 1.17-3.01; p = 0.01), 1-year mortality (HR, 1.53; 95% CI, 1.01-2.29; p = 0.04), and overall mortality (HR, 1.43; 95% CI, 1.08-1.90; p = 0.01). Preoperative sarcopenia was associated with high rates of graft failure and mortality in LDLT recipients. Therefore, preoperative sarcopenia may be a strong predictor of the surgical prognosis in LDLT recipients.

Is there any correlation between liver graft regeneration and recipient's pretransplant skeletal muscle mass?-a study in extended left lobe graft living-donor liver transplantation

BACKGROUND

The end-stage liver disease causes a metabolic dysfunction whose most prominent clinical feature is the loss of skeletal muscle mass (SMM). In living-donor liver transplantation (LDLT), liver graft regeneration (GR) represents a crucial process to normalize the portal hypertension and to meet the metabolic demand of the recipient. Limited data are available on the correlation between pre-LDLT low SMM and GR.

METHODS

Retrospective study on a cohort of 106 LDLT patients receiving an extended left liver lobe graft. The skeletal muscle index (SMI) at L3 level was used for muscle mass measurement, and the recommended cut-off values of the Japanese Society of Hepatology guidelines were used as criteria for defining low muscularity. GR was evaluated as rate of volume increase at 1 month post-LT [graft regeneration rate (GRR)].

RESULTS

The median GRR at 1 month post-LT was 91% (IQR, 65-128%) and a significant correlation with graft volume-to-recipient standard liver volume ratio (GV/SLV) (rho -0.467, P<0.001), graft-to-recipient weight ratio (GRWR) (rho -0.414, P<0.001), donor age (rho -0.306, P=0.001), 1 month post-LT cholinesterase serum levels (rho 0.397, P=0.002) and pre-LT low muscularity [absent vs. present GRR 97.5% (73.1-130%) vs. 83.5% (45.2-110.9%), P=0.041] was noted. Moreover in male recipients, but not in women, it was shown a direct correlation with pre-LT SMI (rho 0.352, P=0.020) and inverse correlation with 1 month post-LT SMI variation (rho -0.301, P=0.049). A low GRR was identified as an independent prognostic factor for recipient overall survival (HR 6.045, P<0.001).

CONCLUSIONS

Additionally to the hemodynamic factors of portal circulation and the quality of the graft, the metabolic status of the recipients has a significant role in the GR process. A pre-LT low SMM is associated with impaired GRR and this negative impact is more evident in male recipients.

Risk stratification for early bacteremia after living donor liver transplantation: a retrospective observational cohort study

BACKGROUND

This study investigated perioperative clinical risk factors for early post-transplant bacteremia in patients undergoing living donor liver transplantation (LDLT). Additionally, postoperative outcomes were compared between patients with and without early post-transplant bacteremia.

METHODS

Clinical data of 610 adult patients who underwent elective LDLT between January 2009 and December 2018 at Seoul St. Mary's Hospital were retrospectively collected. The exclusion criteria included overt signs of infection within 1 month before surgery. A total of 596 adult patients were enrolled in this study. Based on the occurrence of a systemic bacterial infection after surgery, patients were classified into non-infected and infected groups.

RESULTS

The incidence of bacteremia at 1 month after LDLT was 9.7% (57 patients) and Enterococcus faecium (31.6%) was the most commonly cultured bacterium in the blood samples. Univariate analysis showed that preoperative psoas muscle index (PMI), model for end-stage disease score, utility of continuous renal replacement therapy (CRRT), ascites, C-reactive protein to albumin ratio, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio, and sodium level, as well as intraoperative post-reperfusion syndrome, mean central venous pressure, requirement for packed red blood cells and fresh frozen plasma, hourly fluid infusion and urine output, and short-term postoperative early allograft dysfunction (EAD) were associated with the risk of early post-transplant bacteremia. Multivariate analysis revealed that PMI, the CRRT requirement, the NLR, and EAD were independently associated with the risk of early post-transplant bacteremia (area under the curve: 0.707; 95% confidence interval: 0.667-0.745; p < 0.001). The overall survival rate was better in the non-infected patient group. Among patients with bacteremia, anti-bacterial treatment was unable to resolve infection in 34 patients, resulting in an increased risk of patient mortality. Among the factors included in the model, EAD was significantly correlated with non-resolving infection.

CONCLUSIONS

We propose a prognostic model to identify patients at high risk for a bloodstream bacterial infection; furthermore, our findings support the notion that skeletal muscle depletion, CRRT requirement, systemic inflammatory response, and delayed liver graft function are associated with a pathogenic vulnerability in cirrhotic patients who undergo LDLT.

Predictive utility of the C-reactive protein to albumin ratio in early allograft dysfunction in living donor liver transplantation: A retrospective observational cohort study

BACKGROUND

This study was performed to determine the association between the ratio of C-reactive protein to albumin (CRP/ALB) and the risk of early allograft dysfunction (EAD) in patients undergoing living donor liver transplantation (LDLT).

PATIENTS AND METHODS

A total of 588 adult patients undergoing LDLT were retrospectively investigated, after 22 were excluded because of signs of overt infection or history of ALB infusion. The study population was classified into high and low CRP/ALB ratio groups according to EAD. All laboratory variables, including CRP and ALB, had been collected on the day before surgery. A percentage value for the CRP/ALB ratio (%) was calculated as CRP/ALB × 100.

RESULTS

After LDLT, 83 patients (14.1%) suffered EAD occurrence. A higher CRP/ALB ratio was independently associated with risk of EAD, Model for End-stage Liver Disease score, fresh frozen plasma transfusion, and donor age. Based on a cutoff CRP/ALB ratio (i.e., > 20%), the probability of EAD was significantly (2-fold) higher in the high versus low CRP/ALB group. The predictive utility of CRP/ALB ratio for EAD was greater than those of other inflammatory markers. In addition, patients with a high CRP/ALB ratio had poorer survival than those with a low CRP/ALB ratio during the follow-up period.

CONCLUSIONS

The easily calculated CRP/ALB ratio may allow estimation of the risk of EAD after LDLT and can provide additional information that may facilitate the estimation of a patient's overall condition.

Predictors of early recipient mortality after living donor liver transplantation in a tertiary care center in Egypt

BACKGROUND

Living donor liver transplantation (LDLT) has evolved into a widely accepted therapeutic option. Many different risk factors may affect early mortality after LDLT.

OBJECTIVES

Analyze risk factors that can affect early (<6 months) mortality of patients after LDLT in a single center.

DESIGN

Retrospective chart review of patients who underwent LDLT.

SETTING

University hospital.

PATIENTS AND METHODS

Adult cirrhotic patients who underwent LDLT were classified by early (first 6 months) or late mortality. A full pre, intra- and post-operative evaluation had been done on all patients including a full history, examination and investigations to identify risk factors that might affect mortality post-LDLT.

MAIN OUTCOME MEASURES

Determination of pre-, intra- or postoperative factors that might affect recipient mortality post-LDLT.

SAMPLE SIZE

123.

RESULTS

Pre-operative factors that increased early mortality in a univariate analysis were higher model for end-stage liver disease (MELD) scores, lower graft-recipient weigh ratio (GRWR), older donor age, and recurrent spontaneous bacterial peritonitis. Intraoperative factors included more transfusion units of blood, plasma, platelets and cryoprecipitate, a longer time for cold and warm ischemia, and a longer anhepatic phase among others. Postoperative factors included a longer ICU or hospital stay and abnormal postoperative laboratory data. In the final logistic regression model, the most significant factors were pre-operative GRWR, length of hospital stay, units of intraoperative blood transfusion, postoperative alanine aminotransferase, postoperative total leukocyte count, and MELD score.

CONCLUSION

LDLT outcomes might be improved by attempting to resolve clinical factors that have been identified as contributors to early post-LDLT mortality.

LIMITATIONS

More risk factors, such as those relevant to patient portal vein hemodynamics, should be included in an analysis of predictors of early mortality.

CONFLICT OF INTEREST

None.

Autophagy Contributes to Liver Regeneration After Portal Vein Ligation in Rats

BACKGROUND This study investigated the effect of 70% portal vein ligation (PVL), a widely used procedure for inducing rapid liver regeneration, on the expression of autophagy-related proteins in non-ligated liver lobes in rats. MATERIAL AND METHODS Rats were subjected to either sham (n=30, major portal vein branches were exposed but kept intact) or PVL (n=30, major portal vein branches were double-ligated) operations. Liver samples were collected 12, 24, 48, 72, and 168 h after the operation. Liver volume, liver color, non-ligated liver percentage, and the expressions of light chain (LC) 3, beclin 1, and cyclin D1 in the non-ligated liver lobes were determined. RESULTS When compared to sham rats, increased (P<0.001) growth of the non-ligated liver lobes was observed in PVL rats as early as 12 h after surgery; an increased (P≤0.001) LC3 II/I ratio was observed in the non-ligated lobes of PVL rats as early as 24 h after surgery. Increased expressions of beclin 1 (P≤0.001) and cyclin D1 (P<0.001) were observed in the non-ligated lobes of PVL rats from 12 to 72 h after surgery and from 12 to 168 h after surgery, respectively, when compared to sham rats. In the non-ligated lobes, the expressions of beclin 1 and cyclin D1 were linearly and positively correlated with the LC3 II/I ratio. CONCLUSIONS Autophagy is activated in the non-ligated liver after PVL. Both beclin 1 and cyclin D1 are linearly and positively correlated with autophagy activity in the PVL-induced rapid liver regeneration model.

Optimizing Livers for Transplantation Using Machine Perfusion versus Cold Storage in Large Animal Studies and Human Studies: A Systematic Review and Meta-Analysis

Background

Liver allograft preservation frequently involves static cold storage (CS) and machine perfusion (MP). With its increasing popularity, we investigated whether MP was superior to CS in terms of beneficial outcomes.

Methods

Human studies and large animal studies that optimized livers for transplantation using MP versus CS were assessed (PubMed/Medline/EMBASE). Meta-analyses were conducted for comparisons. Study quality was assessed according to the Newcastle-Ottawa quality assessment scale and SYRCLE's risk of bias tool.

Results

Nineteen studies were included. Among the large animal studies, lower levels of lactate dehydrogenase (SMD -3.16, 95% CI -5.14 to -1.18), alanine transferase (SMD -2.46, 95% CI -4.03 to -0.90), and hyaluronic acid (SMD -2.48, 95% CI -4.21 to -0.74) were observed in SNMP-preserved compared to CS-preserved livers. NMP-preserved livers showing lower level of hyaluronic acid (SMD -3.97, 95% CI -5.46 to -2.47) compared to CS-preserved livers. Biliary complications (RR 0.45, 95% CI 0.28 to 0.73) and early graft dysfunction (RR 0.56, 95% CI 0.34 to 0.92) also significantly reduced with HMP preservation in human studies. No evidence of publication bias was found.

Conclusions

MP preservation could improve short-term outcomes after transplantation compared to CS preservation. Additional randomized controlled trials (RCTs) are needed to develop clinical applications of MP preservation.