Release of cytokines and hemodynamic instability during the reperfusion of a liver graft

A Review of the Risk Factors and Approaches to Prevention of Post-Reperfusion Syndrome During Liver Transplantation

Post-reperfusion syndrome (PRS) is a severe and highly lethal syndrome that occurs after declamping the portal vein forceps during liver transplantation. It is marked by severe hemodynamic disturbances manifested by decreased mean arterial pressure, increased heart rate and elevated pulmonary artery pressure. The complex pathogenesis of PRS remains understudied. It is generally believed to be related to the large amount of acidic, cold blood that enters the circulation after release of the portal clamp. This blood is rich in oxygen-free radicals and metabolic toxins, which not only aggravate the ischemia-reperfusion injury of the liver but also further attack the systemic organs indiscriminately. Considering the range of possible adverse prognoses including acute kidney injury, delirium and graft nonfunction, it is imperative that clinicians increase their awareness and prevention of PRS. The aim of this article is to review the current risk factors, pathophysiological mechanisms and prevention strategies for PRS.

Bridging the critically ill patient with acute to chronic liver failure to liver transplantation

Liver transplantation (LT) has emerged as an effective therapy for severe forms of acute-on-chronic liver failure (ACLF), an entity characterized by the development of multiorgan failure and high short-term mortality. The aim of critical care management of ACLF patients is to rapidly treat precipitating events and aggressively support failing organs to ensure that patients may successfully undergo LT or, less frequently, recover. Malnutrition and sarcopenia are frequently present, adversely impacting the prognosis of these patients. Management of critical care patients with ACLF is complex and requires the participation of different specialties. Once the patient is stabilized, a rapid evaluation for salvage LT should be performed because the time window for LT is often narrow. The development of sepsis and prolonged organ support may preclude LT or diminish its chances of success. The current review describes strategies to bridge severe ACLF patients to LT, highlights the minimal evaluation required for listing and the currently suggested contraindications to proceed with LT, and addresses different aspects of management during the perioperative and early posttransplant period.

Serum from patients with cirrhosis undergoing liver transplantation induces permeability in human pulmonary microvascular endothelial cells ex vivo

Introduction

Patients with cirrhosis undergoing liver transplantation frequently exhibit systemic inflammation, coagulation derangements, and edema, indicating endothelial dysfunction. This syndrome may worsen after ischemia-reperfusion injury of the liver graft, coincident with organ dysfunction that worsens patient outcomes. Little is known about changes in endothelial permeability during liver transplantation. We hypothesized that sera from these patients would increase permeability in cultured human endothelial cells ex vivo.

Methods

Adults with cirrhosis presenting for liver transplantation provided consent for blood collection during surgery. Sera were prepared at five time points spanning the entire operation. The barrier function of human pulmonary microvascular endothelial cells in culture was assessed by transendothelial resistance measured using the ECIS ZΘ system. Confluent cells from two different endothelial cell donors were stimulated with human serum from liver transplant patients. Pooled serum from healthy men and purified inflammatory agonists served as controls. The permeability response to serum was quantified as the area under the normalized resistance curve. Responses were compared between time points and analyzed for associations with clinical characteristics of liver transplant patients and their grafts.

Results

Liver transplant sera from all time points during surgery-induced permeability in both endothelial cell lines. The magnitude of permeability change was heterogeneous between patients, and there were differences in the effects of sera on the two endothelial cell lines. In one of the cell lines, the severity of liver disease was associated with greater permeability at the start of surgery. In the same cell line, serum collected 15 min after liver reperfusion induced significantly more permeability as compared to that collected at the start of surgery. Early postreperfusion sera from patients undergoing living donor transplants induced more permeability than sera from deceased donor transplants. Sera from two exemplary cases of patients on preoperative dialysis, and one patient with an unexpectedly long warm ischemia time of the liver graft, induced exaggerated and prolonged endothelial permeability.

Discussion

Serum from patients with cirrhosis undergoing liver transplantation induces permeability of cultured human pulmonary microvascular endothelial cells. Increased endothelial permeability during liver transplantation may contribute to organ injury and present a target for future therapeutics.

Interleukin-6 Levels During Normothermic Machine Perfusion Impact Postreperfusion Hemodynamics of Liver Graft Recipients: A Prospective Single-center Observational Study

BACKGROUND

Hemodynamic instability after liver graft reperfusion increases recipient morbidity after liver transplantation. The etiologies of hemodynamic disturbances appear to be multifactorial and are poorly understood. Normothermic machine perfusion (NMP) provides an opportunity to analyze graft quality prior to transplantation. In the present study, we aim to investigate the influence of interleukin-6 (IL-6) levels during NMP on postreperfusion hemodynamics of the recipient.

METHODS

Consecutive NMP-liver transplants at a single-center were prospectively analyzed. Perfusate samples were collected at the beginning, after 6 h, and at the end of perfusion and analyzed for IL-6 levels. Mean arterial pressure (MAP) and catecholamine consumption during surgery were recorded. IL-6 levels at the end of NMP were correlated to donor and perfusion characteristics as well as changes in MAP and catecholamine requirements during the anhepatic and reperfusion phase.

RESULTS

IL-6 perfusate measurements were assessed in 77 livers undergoing NMP and transplantation. Donor age, sex, cold ischemic time, and NMP time did not correlate with IL-6 levels. Perfusates of donation after circulatory death grafts showed higher IL-6 levels at the end of NMP than donation after brain death grafts. However, IL-6 levels at the end of NMP correlated with catecholamine requirements and MAP in the reperfusion phase. Per log10 increase in IL-6 levels, an increase of 42% points in administered catecholamine dose was observed, despite MAP being decreased by 3.6% points compared to baseline values.

CONCLUSIONS

IL-6 levels may be a predictor for recipient hemodynamic instability during liver reperfusion. Larger studies are needed to confirm this finding.

OXIDATIVE study: A pilot prospective observational cohort study protocol examining the influence of peri-reperfusion hyperoxemia and immune dysregulation on early allograft dysfunction after orthotopic liver transplantation

Early allograft dysfunction (EAD) is a functional hepatic insufficiency within a week of orthotopic liver transplantation (OLT) and is associated with morbidity and mortality. The etiology of EAD is multifactorial and largely driven by ischemia reperfusion injury (IRI), a phenomenon characterized by oxygen scarcity followed by paradoxical oxidative stress and inflammation. With the expanded use of marginal allografts more susceptible to IRI, the incidence of EAD may be increasing. This necessitates an in-depth understanding of the innate molecular mechanisms underlying EAD and interventions to mitigate its impact. Our central hypothesis is peri-reperfusion hyperoxemia and immune dysregulation exacerbate IRI and increase the risk of EAD. We will perform a pilot prospective single-center observational cohort study of 40 patients. The aims are to determine (1) the association between peri-reperfusion hyperoxemia and EAD and (2) whether peri-reperfusion perturbed cytokine, protein, and hypoxia inducible factor-1 alpha (HIF-1α) levels correlate with EAD after OLT. Inclusion criteria include age ≥ 18 years, liver failure, and donation after brain or circulatory death. Exclusion criteria include living donor donation, repeat OLT within a week of transplantation, multiple organ transplantation, and pregnancy. Partial pressure of arterial oxygen (PaO2) as the study measure allows for the examination of oxygen exposure within the confines of existing variability in anesthesiologist-administered fraction of inspired oxygen (FiO2) and the inclusion of patients with intrapulmonary shunting. The Olthoff et al. definition of EAD is the primary outcome. Secondary outcomes include postoperative acute kidney injury, pulmonary and biliary complications, surgical wound dehiscence and infection, and mortality. The goal of this study protocol is to identify EAD contributors that could be targeted to attenuate its impact and improve OLT outcomes. If validated, peri-reperfusion hyperoxemia and immune perturbations could be targeted via FiO2 titration to a goal PaO2 and/or administration of an immunomodulatory agent by the anesthesiologist intraoperatively.

Effect of ultrasound-guided stellate ganglion block on inflammatory cytokines and postoperative recovery after partial hepatectomy: a randomised clinical trial

BACKGROUND

Stellate ganglion block (SGB) has been shown to reduce perioperative complications in various surgeries. Because laparoscopic techniques and instruments have advanced during the past two decades, laparoscopic liver resection is being increasingly adopted worldwide. Lesser blood loss, fewer postoperative complications, and shorter postoperative hospital stays are the advantages of laparoscopic liver resection, as compared to conventional open surgery. There is an urgent need for an effective intervention to reduce perioperative complications and accelerate postoperative recovery. This study investigated the effect of ultrasound-guided SGB on enhanced recovery after laparoscopic partial hepatectomy.

METHODS

We compared patients who received SGB with 0.5% ropivacaine (group S) with those who received SGB with 0.9% saline (group N). A total of 58 patients with partial hepatectomy were enrolled (30 S) and (28 N). Before induction of anesthesia, SGB was performed with 0.5% ropivacaine in group S and 0.9% saline in group N.

MAIN OUTCOME

Comparison of serum inflammatory cytokines concentration at each time point.

RESULTS

Main outcome: When comparing IL-6 and IL-10 concentrations among groups, group S showed less variation over time compared to group N. For comparison between groups, the serum IL-6 concentration in group S was lower than that in group N at 6 and 24 h after operation (P < 0.01), and there was a significant linear relationship between serum IL-6 concentration at 24 h after operation and hospitalization situation.

CONCLUSIONS

Ultrasound-guided SGB can stabilize perioperative inflammatory cytokines plays a positive role in the enhanced recovery of patients after laparoscopic partial hepatectomy. The serum IL-6 level within 24 h after surgery may be used as a predictor of hospitalization.

TRIAL REGISTRATION

The study was registered at the ClinicalTrials.gov (Registration date: 13/09/2021; Trial ID: NCT05042583).

Intravenous Ascorbic Acid for the Prevention of Postreperfusion Syndrome in Orthotopic Liver Transplantation: Protocol for a Randomized Controlled Trial

BACKGROUND

Liver transplantation is the last therapeutic option for patients with end-stage liver disease. Postreperfusion syndrome (PRS), defined as a fall in mean arterial pressure of more than 30% within the first 5 minutes after reperfusion of at least 1 minute, can occur in liver transplantation as a deep hemodynamic instability with associated hyperfibrinolysis immediately after reperfusion of the new graft. Its incidence has remained unchanged since it was first described in 1987. PRS is related to ischemia-reperfusion (I/R) injury, whose pathophysiology involves the release of several mediators from both the donor and the recipient. The antioxidant effect of ascorbic acid has been studied in resuscitating patients with septic shock and burns. Even today, there are publications with conflicting results, and there is a need for further studies to confirm or rule out the usefulness of this drug in this group of patients. The addition of ascorbic acid to preservation solutions used in solid organ transplantation is under investigation to harness its antioxidant effect and mitigate I/R injury. Since PRS could be considered a manifestation of I/R injury, we believe that the possible beneficial effect of ascorbic acid on the occurrence of PRS should be investigated.

OBJECTIVE

The aim of this randomized controlled trial is to assess the benefits of ascorbic acid over saline in the development of PRS in adult liver transplantation.

METHODS

We plan to conduct a single-center randomized controlled trial at the Hospital Universitario Ramón y Cajal in Spain. A total of 70 participants aged 18 years or older undergoing liver transplantation will be randomized to receive either ascorbic acid or saline. The primary outcome will be the difference between groups in the incidence of PRS. The randomized controlled trial will be conducted under conditions of respect for fundamental human rights and ethical principles governing biomedical research involving human participants and in accordance with the international recommendations contained in the Declaration of Helsinki and its subsequent revisions.

RESULTS

The enrollment process began in 2020. A total of 35 patients have been recruited so far. Data cleaning and analysis are expected to occur in the first months of 2024. Results are expected around the middle of 2024.

CONCLUSIONS

We believe that this study could be particularly relevant because it will be the first to analyze the clinical effect of ascorbic acid in liver transplantation. Moreover, we believe that this study fills an important gap in the knowledge of the potential benefits of ascorbic acid in the field of liver transplantation, particularly in relation to PRS.

TRIAL REGISTRATION

European Union Drug Regulating Authorities Clinical Trials Database 2020-000123-39; https://tinyurl.com/2cfzddw8; ClinicalTrials.gov NCT05754242; https://tinyurl.com/346vw7sm.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/50091.

Effect of cardiac output - guided hemodynamic management on acute lung injury in pediatric living donor liver transplantation

BACKGROUND

Acute lung injury (ALI) after liver transplantation (LT) may lead to acute respiratory distress syndrome, which is associated with adverse postoperative outcomes, such as prolonged hospital stay, high morbidity, and mortality. Therefore, it is vital to maintain hemodynamic stability and optimize fluid management. However, few studies have reported cardiac output-guided (CO-G) management in pediatric LT.

AIM

To investigate the effect of CO-G hemodynamic management on early postoperative ALI and hemodynamic stability during pediatric living donor LT.

METHODS

A total of 130 pediatric patients scheduled for elective living donor LT were enrolled as study participants and were assigned to the control group (65 cases) and CO-G group (65 cases). In the CO-G group, CO was considered the target for hemodynamic management. In the control group, hemodynamic management was based on usual perioperative care guided by central venous pressure, continuous invasive arterial pressure, urinary volume, etc. The primary outcome was early postoperative ALI. Secondary outcomes included other early postoperative pulmonary complications, readmission to the intense care unit (ICU) for pulmonary complications, ICU stay, hospital stay, and in-hospital mortality.

RESULTS

The incidence of early postoperative ALI was 27.7% in the CO-G group, which was significantly lower than that in the control group (44.6%) (P < 0.05). During the surgery, the incidence of postreperfusion syndrome was lower in the CO-G group (P < 0.05). The level of intraoperative positive fluid transfusions was lower and the rate of dobutamine use before portal vein opening was higher, while the usage and dosage of epinephrine during portal vein opening and vasoactive inotropic score after portal vein opening were lower in the CO-G group (P < 0.05). Compared to the control group, serum inflammatory factors (interleukin-6 and tumor necrosis factor-α), cardiac troponin I, and N-terminal pro-brain natriuretic peptide were lower in the CO-G group after the operation (P < 0.05).

CONCLUSION

CO-G hemodynamic management in pediatric living-donor LT decreases the incidence of early postoperative ALI due to hemodynamic stability through optimized fluid management and appropriate administration of vasopressors and inotropes.

Factors Associated With Postreperfusion Syndrome in Living Donor Liver Transplantation: A Retrospective Study

BACKGROUND

Postreperfusion syndrome (PRS) after portal vein reperfusion during liver transplantation (LT) has been reported to cause rapid hemodynamic changes and is associated with a prolonged postoperative hospital stay, renal failure, and increased mortality. Although there are some reports on risk factors for PRS in brain-dead donor LT, there are a few reports on those in living donor LT. Therefore, we retrospectively reviewed the factors associated with PRS to contribute to the anesthetic management so as to reduce PRS during living donor LT.

METHODS

After approval by the ethics committee of our institution, 250 patients aged ≥20 years who underwent living donor LT at our institution between January 2013 and September 2018 were included in the study. A decrease in mean arterial pressure of ≥30% within 5 minutes after portal vein reperfusion was defined as PRS, and estimates and odds ratio (OR) for PRS were calculated using logistic regression. The backward method was used for variable selection in the multivariable analysis.

RESULTS

Serum calcium ion concentration before reperfusion (per 0.1 mmol/L increase; OR, 0.74; 95% confidence interval (CI), 0.60-0.95; P < .001), preoperative echocardiographic left ventricular end-diastolic diameter (per 1-mm increase: OR, 0.90; 95% CI, 0.85-0.95; P < .001, men [versus women: OR, 2.45; 95% CI, 1.26-4.75; P = .008]), mean pulmonary artery pressure before reperfusion (restricted cubic spline, P = .003), anhepatic period (restricted cubic spline, P = .02), and graft volume to standard liver volume ratio (restricted cubic spline, P = .03) were significantly associated with PRS.

CONCLUSIONS

In living donor LT, male sex and presence of small left ventricular end-diastolic diameter, large graft volume, and long anhepatic period are associated with PRS, and a high calcium ion concentration and low pulmonary artery pressure before reperfusion are negatively associated with PRS.

Cardiovascular disease risk in liver transplant recipients transplanted due to chronic viral hepatitis

Background

Cardiovascular disease (CVD) is a major cause of morbidity and mortality after liver transplantation, mostly in patients transplanted for nonalcoholic steatohepatitis, obesity and diabetes. Few data exist on cardiovascular diseases among patients transplanted for viral hepatitis.

Objective

Our aim is to clarify the cardiovascular risk and subclinical vascular damage among liver transplant recipients for chronic viral hepatitis (i.e. hepatits C virus, hepatis B virus and hepatitis D virus infection).

Methods

Adult patients (age ≥ 18 years) with orthotopic liver transplants (OLT) due to viral hepatitis who signed informed consent, and were admitted for a routine follow-up between June 2019 and September 2020 at the Infectious Disease outpatient clinic of the University of Campania Luigi Vanvitelli, Naples, Italy, were prospectively enrolled. An estimation of cardiovascular risk was assessed using three main risk charts, echocolor-Doppler of epiaortic vessels was performed to assess subclinical Intima-Media changes.

Results

A total of 161 patients were evaluated; of these 15 were excluded because not affected by viral hepatitis. 146 patients were considered. 83 patients (56.8%) were considered at high cardiovascular risk according to Framingham, 54 patients (36.9%) to American Heart Association Arteriosclerotic Cardiovascular Disease (ASCVD) score and 19 (13.0%) to Heart Score. Only 8 patients (5.4%) showed a normal carotid ultrasound, while 52 patients (35.6%) had a carotid artery Intima-Media Thickness (IMT) and 86 (58.9%) an atherosclerotic plaque.

Conclusions

Liver transplant recipients for virus-related associated liver disease are, in light of the high percentage of carotid lesions, at high risk of CVD. Risk charts compared to subclinical carotid lesions which represent damage already established and a real localization of the disease, seem to underestimate the cardiovascular risk. A chronic inflammatory status, could play a key role. It’s important to raise the awareness of cardiovascular risk in liver transplant patients to prevent cardiovascular diseases and improve the timing of early diagnosis of premature vascular lesions.

Literature review of the mechanisms of acute kidney injury secondary to acute liver injury

People exposed to liver ischaemia reperfusion (IR) injury often develop acute kidney injury and the combination is associated with significant morbidity and mortality. Molecular mediators released by the liver in response to IR injury are the likely cause of acute kidney injury (AKI) in this setting, but the mediators have not yet been identified. Identifying the mechanism of injury will allow the identification of therapeutic targets which may modulate both liver IR injury and AKI following liver IR injury.

Postreperfusion syndrome in liver transplantation: Outcomes, predictors, and application for recipient selection

BACKGROUND

This study aimed to identify risk factors for postreperfusion syndrome (PRS) and its impact on LT outcomes.

METHODS

Data analysis was performed in 1021 adult patients undergoing donation after brain death (DBD) LT to identify PRS incidence, the risk factors for PRS development, and its impact on LT outcomes.

RESULTS

The overall incidence of PRS was 16.1%. Independent risk factors for PRS included donor age (odds ratio (OR) 1.01, p = 0.02), donor body mass index (BMI) (OR 1.04, p = 0.003), moderate macrosteatosis (OR 2.48, p = 0.02), and cold ischemia time (CIT) (OR 1.06, p = 0.02). On multivariable analysis for 30-day graft failure, PRS (hazard ratio (HR) 3.49; p<0.001) and Model for End-stage Liver Disease (MELD) score (HR 1.01; p = 0.05) were independent risk factors. Patients were categorized into 4 distinct groups based on PRS risk groups and MELD groups, which showed different 1-year graft survival (p<0.001). There were comparable outcomes between low PRS risk - high MELD and high PRS risk - low MELD group (p = 0.33).

CONCLUSIONS

donor age, donor BMI, moderate macrosteatosis, and CIT were identified as risk factors for the development of PRS in LT using DBD grafts. PRS risk evaluation may improve donor-to-recipient matching based on their MELD scores. This article is protected by copyright. All rights reserved.

Hemodynamic Instability During Liver Transplantation in Patients With End-stage Liver Disease: A Consensus Document from ILTS, LICAGE, and SATA

Hemodynamic instability (HDI) during liver transplantation (LT) can be difficult to manage and increases postoperative morbidity and mortality. In addition to surgical causes of HDI, patient- and graft-related factors are also important. Nitric oxide-mediated vasodilatation is a common denominator associated with end-stage liver disease related to HDI. Despite intense investigation, optimal management strategies remain elusive. In this consensus article, experts from the International Liver Transplantation Society, the Liver Intensive Care Group of Europe, and the Society for the Advancement of Transplant Anesthesia performed a rigorous review of the most current literature regarding the epidemiology, causes, and management of HDI during LT. Special attention has been paid to unique LT-associated conditions including the causes and management of vasoplegic syndrome, cardiomyopathies, LT-related arrhythmias, right and left ventricular dysfunction, and the specifics of medical and fluid management in end-stage liver disease as well as problems specifically related to portal circulation. When possible, management recommendations are made.

Immediate Postoperative Extubation Decreases Pulmonary Complications in Liver Transplant Patients

BACKGROUND

Fast-track anesthesia in liver transplantation (LT) has been discussed over the past few decades; however, factors associated with immediate extubation after LT surgery are not well defined. This study aimed to identify predictive factors and examine impacts of immediate extubation on post-LT outcomes.

METHODS

A total of 279 LT patients between January 2014 and May 2017 were included. Primary outcome was immediate extubation after LT. Other postoperative outcomes included reintubation, intensive care unit stay and cost, pulmonary complications within 90 days, and 90-day graft survival. Logistic regression was performed to identify factors that were predictive for immediate extubation. A matched control was used to study immediate extubation effect on the other postoperative outcomes.

RESULTS

Of these 279 patients, 80 (28.7%) underwent immediate extubation. Patients with anhepatic time >75 minutes and with total intraoperative blood transfusion ≥12 units were less likely to be immediately extubated (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.26-0.89; P = 0.02; OR, 0.11; 95% CI, 0.05-0.21; P < 0.001). The multivariable analysis showed immediate extubation significantly decreased the risk of pulmonary complications (OR, 0.34; 95% CI, 0.15-0.77; P = 0.01). According to a matched case-control model (immediate group [n = 72], delayed group [n = 72]), the immediate group had a significantly lower rate of pulmonary complications (11.1% versus 27.8%; P = 0.012). Intensive care unit stay and cost were relatively lower in the immediate group (2 versus 3 d; P = 0.082; $5700 versus $7710; P = 0.11). Reintubation rates (2.8% versus 2.8%; P > 0.9) and 90-day graft survival rates (95.8% versus 98.6%; P = 0.31) were similar.

CONCLUSIONS

Immediate extubation post-LT in appropriate patients is safe and may improve patient outcomes and resource allocation.

Stress burden related to postreperfusion syndrome may aggravate hyperglycemia with insulin resistance during living donor liver transplantation: A propensity score-matching analysis

Background

We investigated the impact of postreperfusion syndrome (PRS) on hyperglycemia occurrence and connecting (C) peptide release, which acts as a surrogate marker for insulin resistance, during the intraoperative period after graft reperfusion in patients undergoing living donor liver transplantation (LDLT) using propensity score (PS)-matching analysis.

Patients and methods

Medical records from 324 adult patients who underwent elective LDLT were retrospectively reviewed, and their data were analyzed according to PRS occurrence (PRS vs. non-PRS groups) using the PS-matching method. Intraoperative levels of blood glucose and C-peptide were measured through the arterial or venous line at each surgical phase. Hyperglycemia was defined as a peak glucose level >200 mg/dL, and normal plasma concentrations of C-peptide in the fasting state were taken to range between 0.5 and 2.0 ng/mL.

Results

After PS matching, there were no significant differences in pre- and intra-operative recipient findings and donor-graft findings between groups. Although glucose and C-peptide levels continuously increased through the surgical phases in both groups, glucose and C-peptide levels during the neohepatic phase were significantly higher in the PRS group than in the non-PRS group, and larger changes in levels were observed between the preanhepatic and neohepatic phases. There were higher incidences of C-peptide levels >2.0 ng/mL and peak glucose levels >200 mg/dL in the neohepatic phase in patients with PRS than in those without. PRS adjusted for PS with or without exogenous insulin infusion was significantly associated with hyperglycemia occurrence during the neohepatic phase.

Conclusions

Elucidating the association between PRS and hyperglycemia occurrence will help with establishing a standard protocol for intraoperative glycemic control in patients undergoing LDLT.

Cardiovascular and Metabolic Consequences of Liver Transplantation: A Review

Liver transplantation (LT) is considered the curative treatment option for selected patients who suffer from end-stage or acute liver disease or hepatic malignancy (primary). After LT, patients should be carefully monitored for complications that may appear, partially due to immunosuppressive therapy, but not entirely. Cardiovascular diseases are frequently encountered in patients with LT, being responsible for high morbidity and mortality. Patients with underlying cardiovascular and metabolic pathologies are prone to complications after the transplant, but these complications can also appear de novo, mostly associated with immunosuppressants. Metabolic syndrome, defined by obesity, hypertension, dyslipidemia, and hyperglycemia, is diagnosed among LT recipients and is aggravated after LT, influencing the long-term survival. In this review, our purpose was to summarize the current knowledge regarding cardiovascular (CV) diseases and the metabolic syndrome associated with LT and to assess their impact on short and long-term morbidity and mortality.

The dawn of liver perfusion machines

PURPOSE OF REVIEW

Despite high demand, a severe shortage of suitable allografts limits the use of liver transplantation for the treatment of end-stage liver disease. The transplant community is turning to the utilization of high-risk grafts to fill the void. This review summarizes the reemergence of ex-vivo machine perfusion for liver graft preservation, including results of recent clinical trials and its specific role for reconditioning DCD, steatotic and elderly grafts.

RECENT FINDINGS

Several phase-1 clinical trials demonstrate the safety and feasibility of machine perfusion for liver graft preservation. Machine perfusion has several advantages compared with static cold storage and may provide superior transplantation outcomes, particularly for marginal grafts. Ongoing multicenter trials aim to confirm the results of preclinical and pilot studies and establish the clinical utility of ex-vivo liver machine perfusion.

SUMMARY

Mounting evidence supports the benefits of machine perfusion for preservation of liver grafts. Thus, machine perfusion is a promising strategy to expand the donor pool by reconditioning and assessing viability of DCD, elderly and steatotic grafts during the preservation period. Additionally, machine perfusion will serve as a platform to facilitate graft intervention and modification to further optimize marginal grafts.

Effects of retrograde reperfusion on the intraoperative internal environment and hemodynamics in classic orthotopic liver transplantation

Background

To investigate the effects of retrograde reperfusion on the intraoperative internal environment and hemodynamics in classic orthotopic liver transplantation (OLT).

Methods

Thirty patients were undergone classic OLT using retrograde reperfusion in our center. Blood sampling was done at different time points including: Before blood venting via the portal vein (PV), 10 mL of blood was collected from the inferior vena cava (T₀); During retrograde reperfusion through the inferior vena cava (IVC), 10 mL of blood was collected when the volume of blood venting reached 10 mL (T₁), 100 mL (T₂), and 200 mL (T₃), respectively. 5 mL of blood was analyzed using a NOVA-f–type Blood Gas Analyzer. The remaining 5 mL was measured to determine the level of IL-1β using an enzyme-linked immunosobent assay.

Results

All operations were completed successfully, and postreperfusion syndrome (PRS) occurred in 6 patients (20%). The most notable findings were significant changes at T₁, T₂ and T₃, including pH value, PvO₂, SvO₂, BEecf, HCO₃⁻, Lac, K⁺, Ca²⁺ and IL-1β, compared with T₀ (P < 0.05). Yet their levels at T₃ were not back to the level at T₀ (P < 0.05).

Conclusion

This retrograde perfusion could eliminate some harmful metabolites inside the donor liver in time and reduce acid-base and electrolyte disorders as well as drastic hemodynamic fluctuations after recirculation during classic OLT.

Diagnosis, Incidence, Predictors and Management of Postreperfusion Syndrome in Pediatric Deceased Donor Liver Transplantation: A Single-Center Study

Background

Postreperfusion syndrome (PRS) is a dreadful and well-documented complication in adult liver transplantation (LT). However, information regarding PRS in pediatric LT is still scarce. We aimed to identify the incidence, risk factors and associated outcomes of pediatric LT in a single-center study.

Material/Methods

The medical records of 75 consecutive pediatric patients who underwent deceased donor liver transplantation (DDLT) from July 2015 to October 2017 were retrospectively reviewed. PRS was determined according to the Peking criteria when significant arrhythmia or refractory hypotension occurred following revascularization of the liver graft. Patients were divided into PRS and non-PRS groups. Preoperative, intraoperative, and postoperative data were collected and compared between the 2 groups. Independent risk factors for PRS were analyzed using binary logistic regression analysis.

Results

PRS occurred in 26 patients (34.7%). Univariate analysis showed that the graft-to-recipient weight ratio (P=0.023), donor warm ischemia time (P<0.001), and the use of an expanded criteria donor (ECD) liver graft (P<0.001) were significant predictors of PRS. Binary logistic regression showed that the use of an ECD liver graft (odds ratio [OR]: 18.668; 95% confidence interval [95% CI]: 4.866–71.622) and lower hematocrit (HCT) level before reperfusion (OR: 0.878; 95% CI: 0.782–0.985) were independent predictors of PRS. PRS was significantly associated with early allograft dysfunction (73.1% vs. 18.4%, P<0.001), primary nonfunction (11.5% vs. 0.0%, P=0.039), and a prolonged hospital stay (median: 30.5 vs. 21.0, P=0.007).

Conclusions

The use of an ECD liver graft and lower HCT level before reperfusion were independent risk factors for PRS in pediatric DDLT. Intraoperative PRS occurrence seems to be associated with poor liver allograft function and worsened patient postoperative outcomes.

Visual quality assessment of the liver graft by the transplanting surgeon predicts postreperfusion syndrome after liver transplantation: a retrospective cohort study

Background

The discrepancy between demand and supply for liver transplants (LT) has led to an increased transplantation of organs from extended criteria donors (ECD).

Methods

In this single center retrospective analysis of 122 cadaveric LT recipients, we investigated predictors of postreperfusion syndrome (PRS) including transplant liver quality categorized by both histological assessment of steatosis and subjective visual assessment by the transplanting surgeon using multivariable regression analysis. Furthermore, we describe the relevance of PRS during the intraoperative and postoperative course of LT recipients.

Results

53.3% (n = 65) of the patients suffered from PRS. Risk factors for PRS were visually assessed organ quality of the liver grafts (acceptable: OR 12.2 [95% CI 2.43–61.59], P = 0.002; poor: OR 13.4 [95% CI 1.48–121.1], P = 0.02) as well as intraoperative norepinephrine dosage before reperfusion (OR 2.2 [95% CI 1.26–3.86] per 0.1 μg kg^− 1 min^− 1, P = 0.01). In contrast, histological assessment of the graft was not associated with PRS. LT recipients suffering from PRS were hemodynamically more instable after reperfusion compared to recipients not suffering from PRS. They had lower mean arterial pressures until the end of surgery (P < 0.001), received more epinephrine and norepinephrine before reperfusion (P = 0.02 and P < 0.001, respectively) as well as higher rates of continuous infusion of norepinephrine (P < 0.001) and vasopressin (P = 0.02) after reperfusion. Postoperative peak AST was significantly higher (P = 0.001) in LT recipients with PRS. LT recipients with intraoperative PRS had more postoperative adverse cardiac events (P = 0.05) and suffered more often from postoperative delirium (P = 0.04).

Conclusions

Patients receiving ECD liver grafts are especially prone to PRS. Anesthesiologists should keep these newly described risk factors in mind when preparing for reperfusion in patients receiving high-risk organs.

Association Between Flushed Fluid Potassium Concentration and Severe Postreperfusion Syndrome in Deceased Donor Liver Transplantation

Backgrounds

Predicting the occurrence of severe postreperfusion syndrome (PRS) is clinically challenging. We investigated whether the flushed fluid potassium concentration (FFK) was associated with severe PRS in deceased donor liver transplantation (DDLT).

Material/Methods

Forty adult DDLT recipients were enrolled in this retrospective study. Effluent solution samples were collected at the end of the portal vein flush, and the FFK was determined using a point-of-care blood gas analyzer. The risk factors associated with severe PRS and the clinical outcomes in 2 groups were compared.

Results

Severe PRS occurred in 22 out of 40 patients (55.0%). The FFK of the severe PRS group was significantly higher than that of the non-severe PRS group (median, 9.6 vs. 5.8, P<0.001). Other variables associated with severe PRS included the donor risk index (DRI), Child-Turcotte-Pugh score, donor type, donor warm ischemia time, and Model for End-stage Liver Disease score. The area under the receiver operator characteristic curve for the FFK was 0.982, and the best cut-off value of the FFK for predicting severe PRS was 6.75 mmol/L (100.0% sensitivity and 88.9% specificity). A significant positive correlation was observed between the FFK and DRI (R=0.714). Patients who experienced severe PRS had a higher early allograft dysfunction rate (63.6% vs. 22.2%, P=0.019) and a longer hospital stay (median, 33.0 vs. 24.0, P=0.034).

Conclusions

Both the severity of the recipient’s liver disease and the donor graft factors play an important role in the development of severe PRS in DDLT. An FFK of more than 6.75 mmol/L was associated with severe PRS after reperfusion.

Impact of graft preservation solutions for liver transplantation on early cytokine release and postoperative organ dysfunctions. A pilot study

INTRODUCTION

During liver transplantation, graft ischemia-reperfusion injury leads to a systemic inflammatory response producing postoperative organ dysfunctions. The aim of this observational and prospective study was to compare the impact of Solution de conservation des organes et tissus (SCOT) 15 and University of Wisconsin (UW) preservation solutions on early cytokine release, postreperfusion syndrome and postoperative organ dysfunctions.

METHODS

Thirty-seven liver transplantations were included: 21 in UW Group and 16 in SCOT 15 group. Five cytokines were measured in systemic blood after anesthetic induction, 30minutes after unclamping portal vein and on postoperative day 1.

RESULTS

Following unclamping portal vein, cytokines were released in systemic circulation. Systemic cytokine concentrations were higher in UW than in SCOT 15 group: Interleukin-10, Interleukine-6. In SCOT 15 group, significant reduction of postreperfusion syndrome incidence and acute kidney injury were observed. Alanine and aspartate aminotransferase peak concentrations were higher in SCOT 15 group than in UW group. However, from postoperative day 1 to day 10, aminotransferase returned to normal values and did not differ between groups.

CONCLUSIONS

Compared to UW, SCOT 15 decreases systemic cytokine release resulting from graft ischemia-reperfusion injury and reduces incidence of postreperfusion syndrome and postoperative renal failure.

Hepatic ischemia/reperfusion injury associates with acute kidney injury in liver transplantation: Prospective cohort study

Solid clinical prospective studies investigating the association between hepatic ischemia/reperfusion injury (HIRI) and acute kidney injury (AKI) after liver transplantation are missing. HIRI, reflected by transaminase release, induces AKI in rodents, and retrospective studies suggest a similar association in humans. This prospective cohort study determined risk factors for AKI in 80 adult liver-only recipients. AKI defined by Risk, Injury, Failure, Loss, and End-Stage Kidney Disease (RIFLE) criteria developed in 21 (26%) recipients at 12 hours after reperfusion (interquartile range, 6 hours to postoperative day [POD] 1); 13 progressed from "risk" to "injury"; 5 progressed to "failure." In AKI patients, creatinine (Cr) increased during liver transplantation and was higher versus baseline at 6 hours to POD 4, whereas perioperative Cr remained stable in those without AKI. Plasma heart-type fatty acid-binding protein was higher 12 hours after reperfusion in AKI patients, though urinary kidney injury molecule 1 and neutrophil gelatinase-associated lipocalin were similar between those with or without AKI. Peak aspartate aminotransferase (AST), occurring at 6 hours, was the only independent risk factor for AKI (adjusted odds ratio, 2.42; 95% confidence interval, 1.24-4.91). Early allograft dysfunction occurred more frequently in AKI patients, and intensive care and hospital stays were longer. Patient survival at 1 year was 90% in those with AKI versus 98% in those without AKI. Chronic kidney disease stage ≥ 2 at 1 year was more frequent in patients who had had AKI (89% versus 58%, respectively). In conclusion, AKI is initiated early after liver reperfusion and its association with peak AST suggests HIRI as a determinant. Identifying operating mechanisms is critical to target interventions and to reduce associated morbidity. Liver Transplantation 23 634-644 2017 AASLD.

Early cytokine signatures of ischemia/reperfusion injury in human orthotopic liver transplantation

BACKGROUND. Orthotopic liver transplant (OLT) is the primary therapy for end-stage liver disease and acute liver failure. However, ischemia/reperfusion injury (IRI) can severely compromise allograft survival. To understand the evolution of immune responses underlying OLT-IRI, we evaluated longitudinal cytokine expression profiles from adult OLT recipients before transplant through 1 month after transplant. METHODS. We measured the expression of 38 cytokines, chemokines, and growth factors in preoperative and postoperative recipient circulating systemic blood (before transplant and 1 day, 1 week, and 1 month after transplant) and intraoperative portal blood (before and after reperfusion) of 53 OLT patients and analyzed this expression in relation to biopsy-proven IRI (n = 26 IRI+; 27 IRI-), clinical liver function tests early (days 1-7) after transplant, and expression of genes encoding cytokine receptors in biopsies of donor allograft taken before and after reperfusion. RESULTS. Bilirubin and arginine transaminase levels early after transplant correlated with IRI. Fourteen cytokines were significantly increased in the systemic and/or portal blood of IRI+ recipients that shifted from innate to adaptive-immune responses over time. Additionally, expression of cognate receptors for 10 of these cytokines was detected in donor organ biopsies by RNAseq. CONCLUSION. These results provide a mechanistic roadmap of the early immunological events both before and after IRI and suggest several candidates for patient stratification, monitoring, and treatment. FUNDING. Ruth L. Kirschstein National Research Service Award T32CA009120, Keck Foundation award 986722, and a Quantitative & Computational Biosciences Collaboratory Postdoctoral Fellowship.

Post reperfusion syndrome during liver transplantation: From pathophysiology to therapy and preventive strategies

This review aims at evaluating the existing evidence regarding post reperfusion syndrome, providing a description of the pathophysiologic mechanisms involved and possible management and preventive strategies. A PubMed search was conducted using the MeSH database, “Reperfusion” AND “liver transplantation” were the combined MeSH headings; EMBASE and the Cochrane library were also searched using the same terms. 52 relevant studies and one ongoing trial were found. The concept of post reperfusion syndrome has evolved through years to a multisystemic disorder. The implications of the main organ, recipient and procedure related factors in the genesis of this complex syndrome are discussed in the text as the novel pharmacologic and technical approaches to reduce its incidence. However the available evidence about risk factors, physiopathology and preventive measures is still confusing, the presence of two main definitions and the numerosity of possible confounding factors greatly complicates the interpretation of the studies.

Arrhythmogenic potential develops rapidly at graft reperfusion before the start of hypotension during living-donor liver transplantation

Background

Detailed profiles of acute hypothermia and electrocardiographic (ECG) manifestations of arrhythmogenicity were examined to analyze acute hypothermia and ventricular arrhythmogenic potential immediately after portal vein unclamping (PVU) in living-donor liver transplantation (LT).

Methods

We retrospectively analyzed electronically archived medical records (n = 148) of beat-to-beat ECG, arterial pressure waveforms, and blood temperature (BT) from Swan-Ganz catheters in patients undergoing living-donor LT. The ECG data analyzed were selected from the start of BT drop to the initiation of systolic hypotension after PVU.

Results

On reperfusion, acute hypothermia of < 34℃, < 33℃ and < 32℃ developed in 75.0%, 37.2% and 11.5% of patients, respectively. BT decreased from 35.0℃ ± 0.8℃ to 33.3℃ ± 1.0℃ (range 35.8℃–30.5℃). The median time to nadir of BT was 10 s after PVU. Difference in BT (ΔBT) was weakly correlated with graft-recipient weight ratio (GRWR; r = 0.22, P = 0.008). Compared to baseline, arrhythmogenicity indices such as corrected QT (QTc), Tp-e (T wave peak to end) interval, and Tp-e/QTc ratio were prolonged (P < 0.001 each). ST height decreased and T amplitude increased (P < 0.001 each). However, no correlation was found between ΔBT and arrhythmogenic indices.

Conclusions

In living-donor LT, regardless of extent of BT drop, ventricular arrhythmogenic potential developed immediately after PVU prior to occurrence of systolic hypotension.

Postreperfusion syndrome during liver transplantation

As surgical and graft preservation techniques have improved and immunosuppressive drugs have advanced, liver transplantation (LT) is now considered the gold standard for treating patients with end-stage liver disease worldwide. However, despite the improved survival following LT, severe hemodynamic disturbances during LT remain a serious issue for the anesthesiologist. The greatest hemodynamic disturbance is postreperfusion syndrome (PRS), which occurs at reperfusion of the donated liver after unclamping of the portal vein. PRS is characterized by marked decreases in mean arterial pressure and systemic vascular resistance, and moderate increases in pulmonary arterial pressure and central venous pressure. The underlying pathophysiological mechanisms of PRS are complex. Moreover, risk factors associated with PRS are not fully understood. Rapid and appropriate treatment with vasopressors, volume replacement, or venesection must be provided depending on the cause of the hemodynamic disturbance when hemodynamic instability becomes profound after reperfusion. The negative effects of PRS on postoperative early morbidity and mortality are clear, but the effect of PRS on postoperative long-term mortality remains a matter of debate.

Impact of cytokine release on ventricular function after hepatic reperfusion: a prospective observational echocardiographic study with tissue Doppler imaging

BACKGROUND

Postreperfusion syndrome and haemodynamic instability are predictors for poor outcome after liver transplantation. Cytokine release has been claimed to be responsible for postreperfusion syndrome. However, the underlying pathophysiologic mechanism is not clarified. The aim of this prospective observational study was to correlate cardiac performance (measured by transoesophageal echocardiography (TEE), Doppler and Tissue Doppler Imaging (TDI)) to plasmatic cytokines: IL-6, IL-8, CXCL1, TGF-β and CD40L at 5 different time points during liver transplantation.

METHODS

Seventeen consecutive patients scheduled for orthotopic liver transplantation, age 18 to 75 years without contraindication for transoesophageal echocardiography were included. Patients were monitored with TEE and TDI. Systolic and diastolic cardiac function, MAP, MPAP, CVP, PCWP, CO and blood samples for cytokine assays were recorded or collected after induction, 15 min after vena cava inferior clamping, 2 to 5 min after reperfusion, 60 min after reperfusion and at the end of surgery.

RESULTS

Mean arterial pressure and catecholamine requirements remained unchanged, MPAP, CVP and CO increased, SVR decreased after unclamping. Postreperfusion syndrome did not develop. The haemodynamic parameters and the variations of TEE parameters were consistent with the volume load changes during clamping and declamping and did not reveal systolic or diastolic cardiac dysfunction. All cytokines, except TGF-β, increased.

CONCLUSION

These findings suggest, that significant cytokine release during liver transplantation is not necessarily coincident with haemodynamic instability and impaired cardiac function.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00547924.

Crystalloid flush with backward unclamping may decrease post-reperfusion cardiac arrest and improve short-term graft function when compared to portal blood flush with forward unclamping during liver transplantation

During liver transplant (LT), the release of vasoactive substances into the systemic circulation is associated with severe hemodynamic instability that is injurious to the recipient and/or the post-ischemic graft. Crystalloid flush with backward unclamping (CB) and portal blood flush with forward unclamping (PF) are two reperfusion methods to reduce reperfusion-related cardiovascular perturbations in our center. The primary aim of this study was to compare these two methods. After institutional review board (IRB) approval, cadaveric whole LT cases performed between 2003 and 2008 were reviewed. Patients were divided into two groups based on reperfusion methods: CB or PF. After background matching with propensity score, the effect of each method on post-operative graft function was assessed in detail. In our cohort of 478 patients, CB was used in 313 grafts and PF in 165. Thirty-day graft survival was lower, and risk of retransplantation was higher in PF. Multivariable model showed that CB is an independent factor to reduce primary non-function, cardiac arrest and improve 30-d graft survival. Also, the incidence of ischemic-type biliary lesions was significantly higher in the PF group. Reperfusion methods affect intraoperative hemodynamics and post-transplant outcome. CB allows for control over temperature and composition of the perfusate, perfusion pressure, and the rate of infusion.

Intrarenal resistance index for the assessment of acute renal injury in a rat liver transplantation model

Background

Acute kidney injury (AKI) is a common complication after liver transplantation (LT) and associated with a high mortality. The renal resistive index (RI) is used to assess early renal function impairment in critical care patients. However, limited data are available concerning changes of renal RI and the development of AKI early after reperfusion. We approached to investigate the changes of renal RI and AKI after reperfusion in a rat liver transplantation model.

Methods

Rats were randomly divided into sham group or LT group. Ten rats in each group were used for the hemodynamic study and twenty for Doppler measurements during the procedure. Ten rats were sacrificed 30 min or 2 h after the reperfusion. We harvested kidneys, serum and urine for further analysis of the renal function.

Results

The intrarenal RI increased significantly in the anhepatic stage and decreased significantly after the reperfusion in the LT group compared with sham group (P < 0.05). AKI was seen after the reperfusion in the LT group. No correlation was noted between the RI and renal function parameters 30 min after reperfusion.

Conclusions

The intrarenal RI increased significantly during the anhepatic stage, and decreased significantly early after the reperfusion. Intrarenal RI was unable to assess renal function in a rat liver transplantation model.

Association between plasma cyclic guanosine monophosphate levels and hemodynamic instability during liver transplantation

The activation of cyclic guanosine monophosphate (cGMP) production in patients with end-stage liver disease (ESLD) has been associated with hemodynamic instability during orthotopic liver transplantation (OLT). The aim of this prospective, observational study was to investigate the involvement of cGMP in the mediation of profound hypotension during liver graft reperfusion. An additional objective was to determine whether preoperative cGMP levels are associated with intraoperative hemodynamic instability. Forty-four consecutive patients undergoing OLT were included in the study. Blood samples for cGMP analysis were obtained from (1) the radial artery before the surgical incision; (2) the radial artery, portal vein, and flush blood during the anhepatic phase; and (3) the radial artery 20 minutes after liver graft reperfusion. On the basis of a statistical analysis, the patients were divided into 2 groups: group 1 (preoperative cGMP level ≥ 0.05 μmol/L) and group 2 (preoperative cGMP level < 0.05 μmol/L). We demonstrated a significant correlation between the preoperative levels of cGMP and the amount of catecholamine required to maintain hemodynamic stability during reperfusion (r = 0.52, P < 0.001), the length of the hospital stay (r = 0.38, P = 0.01), and the length of the intensive care unit (ICU) stay (r = 0.44, P = 0.004). We also demonstrated a significantly higher intraoperative catecholamine requirement (P < 0.001) and a prolonged postoperative ICU stay (P = 0.02) in group 1 patients versus group 2 patients. In conclusion, this study demonstrates increased baseline cGMP production in patients with ESLD, which is significantly associated with severe hypotension during OLT. We suggest that preoperative levels of cGMP correlate with hemodynamic instability during liver graft reperfusion.

Cardiotrophin-1 reduces ischemia/reperfusion injury during liver transplant

BACKGROUND

Orthotopic liver transplantation (OLT) is currently the elective treatment for advanced liver cirrhosis and acute liver failure. Ischemia/reperfusion damage may jeopardize graft function during the postoperative period. Cardiotrophin-1 (CT-1) has demonstrated cytoprotective properties in different experimental models of liver injury. There is no evidence to demonstrate its potential use in the prevention of the ischemia/reperfusion injury that occurs during OLT. The present study is the first report to show that the administration of CT-1 to donors would benefit the outcome of OLT.

MATERIALS AND METHODS

We tested the cytoprotective effect of CT-1 administered to the donor prior to OLT in an experimental pig model. Hemodynamic changes, hepatic histology, cell death parameters, activation of cell signaling pathways, oxidative and nitrosative stress, and animal survival were analyzed.

RESULTS

Our data showed that CT-1 administration to donors increased animal survival, improved cardiac and respiratory functions, and reduced hepatocellular injury as well as oxidative and nitrosative stress. These beneficial effects, related to the activation of AKT, ERK, and STAT3, reduced caspase-3 activity and diminished IL-1β and TNF-α expression together with IL-6 upregulation in liver tissue.

CONCLUSIONS

The administration of CT-1 to donors reduced ischemia/reperfusion injury and improved survival in an experimental pig model of OLT.

Glycemic management in living donor liver transplantation for patients with glycogen storage disease type 1b

GSD type 1b is an autosomal recessive inborn error of carbohydrate metabolism caused by defects of the G6Pase translocase (G6PT). Patients with GSD1b have severe hypoglycemia with several clinical manifestations of hepatomegaly, obesity, a doll-like face, and neutropenia. LT has been indicated for severe glucose intolerance. This study retrospectively reviewed glycemic management of eight children with a diagnosis of GSD1b who underwent liver transplantation (LDLT). Between November 2005 and September 2011, 172 children underwent LDLT, of which eight (4.7%) were indicated for GSD1b. Glucose-rich solution was placed in all children when preoperative fasting started to prevent preoperative hypoglycemia. During the reperfusion of graft, the glucose administration could significantly be reduced to maintain the proper blood glucose level, while the dosage of glucose administration prior to reperfusion of graft was significantly higher in the patients with GSD1b in comparison with patients with BA. The current series also showed significantly high incidence of infectious complications in the patients with GSD1b owing to persistent neutropenia after LDLT. All patients are doing well with an excellent quality of life owing to the stabilization of glucose intolerance. This current study clearly documented drastic change in glycemic management in LDLT. Cautious perioperative management to prevent hypoglycemia and infection is crucial for successful LT.

Chronic bile duct hyperplasia is a chronic graft dysfunction following liver transplantation

AIM: To investigate pathological types and influential factors of chronic graft dysfunction (CGD) following liver transplantation (LT) in rats.

METHODS: The whole experiment was divided into three groups: (1) normal group (n = 12): normal BN rats without any drug or operation; (2) syngeneic transplant group (SGT of BN-BN, n = 12): both donors and recipients were BN rats; and (3) allogeneic transplant group (AGT of LEW-BN, n = 12): Donors were Lewis and recipients were BN rats. In the AGT group, all recipients were subcutaneously injected by Cyclosporin A after LT. Survival time was observed for 1 year. All the dying rats were sampled, biliary tract tissues were performed bacterial culture and liver tissues for histological study. Twenty-one day after LT, 8 rats were selected randomly in each group for sampling. Blood samples from caudal veins were collected for measurements of plasma endotoxin, cytokines and metabonomic analysis, and faeces were analyzed for intestinal microflora.

RESULTS: During the surgery of LT, no complications of blood vessels or bile duct happened, and all rats in each group were still alive in the next 2 wk. The long term observation revealed that a total of 8 rats in the SGT and AGT groups died of hepatic graft diseases, 5 rats in which died of chronic bile duct hyperplasia. Compared to the SGT and normal groups, survival ratio of rats significantly decreased in the AGT group (P < 0.01). Moreover, liver necrosis, liver infection, and severe chronic bile duct hyperplasia were observed in the AGT group by H and E stain. On 21 d after LT, compared with the normal group (25.38 ± 7.09 ng/L) and SGT group (33.12 ± 10.26 ng/L), plasma endotoxin in the AGT group was remarkably increased (142.86 ± 30.85 ng/L) (both P < 0.01). Plasma tumor necrosis factor-α and interleukin-6 were also significantly elevated in the AGT group (593.6 ± 171.67 pg/mL, 323.8 ± 68.30 pg/mL) vs the normal (225.5 ± 72.07 pg/mL, 114.6 ± 36.67 pg/mL) and SGT groups (321.3 ± 88.47 pg/mL, 205.2 ± 53.06 pg/mL) (P < 0.01). Furthermore, Bacterial cultures of bile duct tissues revealed that the rats close to death from the SGT and AGT groups were strongly positive, while those from the normal group were negative. The analysis of intestinal microflora was performed. Compared to the normal group (7.98 ± 0.92, 8.90 ± 1.44) and SGT group (8.51 ± 0.46, 9.43 ± 0.69), the numbers of Enterococcus and Enterobacteria in the AGT group (8.76 ± 1.93, 10.18 ± 1.64) were significantly increased (both P < 0.01). Meanwhile, compared to the normal group (9.62 ± 1.60, 9.93 ± 1.10) and SGT group (8.95 ± 0.04, 9.02 ± 1.14), the numbers of Bifidobacterium and Lactobacillus in the AGT group (7.83 ± 0.72, 8.87 ± 0.13) were remarkably reduced (both P < 0.01). In addition, metabonomics analysis showed that metabolic profiles of plasma in rats in the AGT group were severe deviated from the normal and SGT groups.

CONCLUSION: Chronic bile duct hyperplasia is a pathological type of CGD following LT in rats. The mechanism of this kind of CGD is associated with the alterations of inflammation, intestinal barrier function and microflora as well as plasma metabolic profiles.

Liver graft injury induced by ischemia and reperfusion secondary to retrograde reperfusion

AIM: To evaluate the influence of retrograde reperfusion on ischemia/reperfusion injury in a rat model of liver transplantation.

METHODS: Thirty-six male Sprague-Dawley rats undergoing orthoptic liver transplantation were divided into three groups (n = 12 for each group): group 1, antegrade reperfusion via the portal vein; group 2, antegrade reperfusion simultaneously via the portal vein and hepatic artery; group 3: retrograde reperfusion via the vena cava. Serum parameters were determined 1, 6 and 24 h after operation. Liver samples were taken for histological assessment. Cell apoptotic index was determined.

RESULTS: Rats of group 3 showed significantly lower serum level of aspartate aminotransferase compared to groups 1 and 2 (968.4 U/L ± 221.5 U/L vs 1 801.6 U/L ± 324.5 U/L, 2 564.1 U/L ± 410.3 U/L, P = 0.003, 0.000). Serum level of aspartate aminotransferase was significantly lower in group 1 than in group 2. The liver of rats of group 3 showed significantly less leukocytic infiltrates compared to groups 1 and group 2. The apoptotic index was lower in group 3 than in group 1 and 2.

CONCLUSION: Retrograde reperfusion leads to a lower level of ischemia/reperfusion injury than antegrade reperfusion in rats undergoing liver transplantation.