Massive blood transfusion after the first cut in liver transplantation predicts renal outcome and survival

Role of intelligent/interactive qualitative and quantitative analysis-three-dimensional estimated model in donor-recipient size mismatch following deceased donor liver transplantation

BACKGROUND

Donor-recipient size mismatch (DRSM) is considered a crucial factor for poor outcomes in liver transplantation (LT) because of complications, such as massive intraoperative blood loss (IBL) and early allograft dysfunction (EAD). Liver volumetry is performed routinely in living donor LT, but rarely in deceased donor LT (DDLT), which amplifies the adverse effects of DRSM in DDLT. Due to the various shortcomings of traditional manual liver volumetry and formula methods, a feasible model based on intelligent/interactive qualitative and quantitative analysis-three-dimensional (IQQA-3D) for estimating the degree of DRSM is needed.

AIM

To identify benefits of IQQA-3D liver volumetry in DDLT and establish an estimation model to guide perioperative management.

METHODS

We retrospectively determined the accuracy of IQQA-3D liver volumetry for standard total liver volume (TLV) (sTLV) and established an estimation TLV (eTLV) index (eTLVi) model. Receiver operating characteristic (ROC) curves were drawn to detect the optimal cut-off values for predicting massive IBL and EAD in DDLT using donor sTLV to recipient sTLV (called sTLVi). The factors influencing the occurrence of massive IBL and EAD were explored through logistic regression analysis. Finally, the eTLVi model was compared with the sTLVi model through the ROC curve for verification.

RESULTS

A total of 133 patients were included in the analysis. The Changzheng formula was accurate for calculating donor sTLV (P = 0.083) but not for recipient sTLV (P = 0.036). Recipient eTLV calculated using IQQA-3D highly matched with recipient sTLV (P = 0.221). Alcoholic liver disease, gastrointestinal bleeding, and sTLVi > 1.24 were independent risk factors for massive IBL, and drug-induced liver failure was an independent protective factor for massive IBL. Male donor-female recipient combination, model for end-stage liver disease score, sTLVi ≤ 0.85, and sTLVi ≥ 1.32 were independent risk factors for EAD, and viral hepatitis was an independent protective factor for EAD. The overall survival of patients in the 0.85 < sTLVi < 1.32 group was better compared to the sTLVi ≤ 0.85 group and sTLVi ≥ 1.32 group (P < 0.001). There was no statistically significant difference in the area under the curve of the sTLVi model and IQQA-3D eTLVi model in the detection of massive IBL and EAD (all P > 0.05).

CONCLUSION

IQQA-3D eTLVi model has high accuracy in predicting massive IBL and EAD in DDLT. We should follow the guidance of the IQQA-3D eTLVi model in perioperative management.

Metabolomic analysis of the inhibitory effect of phthalates and bisphenol A on the antioxidant activity of vitamin D in human samples using liquid chromatography–mass spectrometry

Vitamin D is important because it has roles in maintaining musculoskeletal health, redox homeostasis, and the immune system; however, it is commonly dysregulated by endocrine disrupting chemicals, particularly phthalates and bisphenol A (BPA). Continuous exposure to phthalates and BPA may alter the endogenous metabolite profiles associated with vitamin D activity, although the specific metabolites are yet to be identified. In this study, we identified the endogenous metabolites altered by phthalates and BPA exposure through untargeted metabolic profiling and investigated the role of these metabolites in vitamin D activity. Plasma metabolic profiling using liquid chromatography-mass spectrometry was performed in two groups: severe 25-hydroxyvitamin D (25(OH)D) deficiency and high exposure to phthalates and BPA (Group A) and 25(OH)D deficiency and low exposure to phthalates and BPA (Group B). Multivariate analysis revealed a distinct separation between the two groups. A total of six metabolites were annotated, of which levels of two were significantly different between the two groups: platelet-activating factor (PAF) C16 or lysophosphatidylcholine (lysoPC) 18:0, and 11Z-eicosenamide. Plasma levels of PAF C16 or lysoPC 18:0 were increased in Group A and exhibited an area under the curve of 0.769 with an accuracy of 74.4% in a receiver operating characteristic curve analysis. These metabolites are generated as byproducts of lipid peroxidation, which supports the fact that phthalates and BPA induce oxidative stress in cells. Furthermore, PAF C16 and lysoPC 18:0 may be involved in the network that interferes with the antioxidant activity of vitamin D upon exposure to phthalates and BPA. This study results provide useful information on how the activity of vitamin D on the antioxidant system is inhibited when exposure to phthalates and BPA.

Blood loss during liver transplantation is a predictor of postoperative thrombosis

Liver transplantation (LT) is an effective way to cure end-stage liver diseases (ESLDs), which have generally been regarded as examples of acquired bleeding disorders. However, postoperative thrombosis after LT is recognised and remains a life-threatening complication. This study aimed to show that blood loss during LT is a predictor of postoperative thrombosis and to establish a predictive model. We analysed the medical records of all patients who underwent LT at the First Affiliated Hospital of Xi'an Jiaotong University from January 2017 to April 2019 to identify the risk factors for post-transplant thrombosis. The predictive nomogram was established based on independent predictors identified by logistic regression analysis. Blood loss during LT of ≥31.25 mL/kg can predict postoperative thrombosis, and the nomogram achieved an accurate prediction.

Protocol for a prospective double-blind, randomised, placebo-controlled feasibility trial of octreotide infusion during liver transplantation

INTRODUCTION

Liver transplantation is a complex operation that can provide significant improvements in quality of life and survival to the recipients. However, serious complications are common and include major haemorrhage, hypotension and renal failure. Blood transfusion and the development of acute kidney injury lead to both short-term and long-term poor patient outcomes, including an increased risk of death, graft failure, length of stay and reduced quality of life. Octreotide may reduce the incidence of renal dysfunction, perioperative haemorrhage and enhance intraoperative blood pressure. However, octreotide does have risks, including resistant bradycardia, hyperglycaemia and hypoglycaemia and QT prolongation. Hence, a randomised controlled trial of octreotide during liver transplantation is needed to determine the cost-efficacy and safety of its use; this study represents a feasibility study prior to this trial.

METHODS AND ANALYSIS

We describe a multicentre, double-blind, randomised, placebo-controlled feasibility study of continuous infusion of octreotide during liver transplantation surgery. We will recruit 30 adult patients at two liver transplant centres. A blinded infusion during surgery will be administered in a 2:1 ratio of octreotide:placebo. The primary outcomes will determine the feasibility of this study design. These include the recruitment ratio, correct administration of blinded study intervention, adverse event rates, patient and clinician enrolment refusal and completion of data collection. Secondary outcome measures of efficacy and safety will help shape future trials by assessing potential primary outcome measures and monitoring safety end points. No formal statistical tests are planned. This manuscript represents study protocol number 1.3, dated 2 June 2021.

ETHICS AND DISSEMINATION

This study has received Research Ethics Committee approval. The main study outcomes will be submitted to an open-access journal.

TRIAL SPONSOR

The Joint Research Office, University College London, UK.Neither the sponsor nor the funder have any role in study design, collection, management, analysis and interpretation of data, writing of the study report or the decision to submit the report for publication.

TRIAL REGISTRATION

The study is registered with ClinicalTrials.gov (NCT04941911) with recruitment due to start in August 2021 with anticipated completion in July 2022.

CLINICAL TRIALS UNIT

Surgical and Interventional Group, Division of Surgery & Interventional Science, University College London.

Intraoperative Factors Associated With Early Recipient Death After Adult-to-Adult Living Donor Liver Transplant

OBJECTIVES

Living donor liver transplant is the gold standard therapy for patients with terminal hepatic disorders for whom no alternative therapy is available. The primary aim was to assess different intraoperative factors that may predict early death after adult-to-adult living donor liver transplant. The secondary aim was to assess the effect of small-for-size syndrome on mortality.

MATERIALS AND METHODS

This retrospective multicenter cohort study was performed on records from 145 adults with cirrhosis who had received a right lobe living donor liver transplant. Patients were divided according to the occurrence of short-term mortality (death within the first month after transplant). The primary intraoperative parameters included graft weight, surgical duration, mean blood pressure, serum lactate and sodium bicarbonate, transfusions, durations of cold and warm ischemia and anhepatic phase, input and output during surgery, and portal venous pressures.

RESULTS

There were statistically significant variations between both cohorts for number of units of packed red blood cells, durations of cold and warm ischemia and anhepatic phase, preclamp and postreperfusion portal venous pressures, average urine output, mean serum lactate, mean blood pressure, and surgical duration (P ⟨ .001). Also, there were significant differences in the number of platelets, units of fresh frozen plasma, and mean sodium bicarbonate (P = .025, .003, and .035, respectively). Of the 25 patients who died within the early postoperative period, 20 had developed small-for-size syndrome (P ⟨ .001).

CONCLUSIONS

A variety of intraoperative risk factors may affect early posttransplant mortality, which suggests the high complexity of living donor liver transplants and the need for well-trained experienced teams to perform these surgeries.

Cell Salvage During Liver Transplantation for Hepatocellular Carcinoma: A Retrospective Analysis of Tumor Recurrence Following Irradiation of the Salvaged Blood

BACKGROUND

Orthotopic liver transplantation (OLT) is the treatment option for early-stage hepatocellular carcinoma (HCC). OLT is often associated with high blood loss, requiring blood transfusion. Retransfusion of autologous blood is a key part of blood conservation. There are, however, concerns that the retransfusion of salvaged blood might cause the spread of cancer cells and induce metastasis. Irradiation of salvaged blood before retransfusion eliminates viable cancer cells. Here, we analyzed the incidence of tumor recurrence in patients with HCC undergoing OLT who received irradiated cell-salvaged blood during transplant surgery.

METHODS

We retrospectively analyzed patients undergoing OLT for HCC between 2002 and 2018 at our center. We compared the tumour recurrence in patients who received no retransfusion of autologous blood with patients who received autologous blood with or without preceding irradiation of the blood.

RESULTS

Fifty-one (40 male, 11 female) patients were included in the analysis; 10 patients developed tumor recurrence within a time period of 2.45 ± 2.0 years. Statistical analysis revealed that there was no significant difference in tumor recurrence between patients who received autologous blood with or without irradiation.

CONCLUSION

Intraoperative transfusion of cell-salvaged blood did not increase tumor recurrence rates. Cell salvage should be used in liver transplantation of HCC patients as part of a blood conservation strategy. The effect of blood irradiation on tumor recurrence could not be definitively evaluated.

Effect of cumulative fluid balance on acute kidney injury and patient outcomes after orthotopic liver transplantation: A retrospective cohort study

AIM

Acute kidney injury (AKI) is a serious complication following orthotopic liver transplantation (OLT) and it affects long-term patient survival. The aims of this study were to identify the effects of cumulative fluid balance (FB) on early post-OLT AKI and adverse outcomes and to construct a model to predict AKI.

METHODS

We retrospectively analysed 146 adult patients who underwent OLT. AKI severity was classified according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Univariate and multivariate logistic regression analyses were used to evaluate the association between cumulative FB and post-OLT AKI. The Kaplan-Meier method was used to estimate the survival rate.

RESULTS

Within the perioperative period of 72 hours, 50% (66/132) of patients developed AKI, with 36 (54%), 16 (24%) and 14 (21%) patients having AKI stages 1, 2 and 3, respectively. The cumulative FB was the risk factors for post-OLT AKI (odds ratio [OR], 1.011; 95% confidence interval [CI], 1.156~6.001; P = .021). Preoperative albumin was a protective factor for post-OLT AKI (OR, 0.309; 95% CI, 0.140~0.731; P = .007). The AKI group requires renal replacement therapy (RRT) more (15.2% vs 0%, P = .001) and associated with postoperative complications (56% vs 28.8%, P = .003). The complication-free survival was lower in the AKI group ([11.90 vs 18.74] months, χ² = 9.60, P = .002).

CONCLUSION

Cumulative FB within 72 hours is associated with post-OLT AKI and requires RRT. Cumulative FB impacts the long-term complication-free survival of the recipients.

Early detection of acute kidney injury in the perioperative period of liver transplant with neutrophil gelatinase-associated lipocalin

Background

Acute kidney injury (AKI) is a common complication in patients undergoing liver transplant (LT) and is associated with high morbidity and mortality. We aim to evaluate the pattern of urine and plasma neutrophil gelatinase-associated lipocalin (NGAL) elevation during the perioperative period of LT and to assess it as a prognostic marker for AKI progression, need for dialysis and mortality.

Methods

We assessed NGAL levels before induction of anesthesia, after portal reperfusion and at 6, 18, 24, and 48 h after surgery. Patients were monitored daily during the first week after LT.

Results

Of 100 enrolled patients undergoing liver transplant, 59 developed severe AKI based on the KDIGO serum creatinine (sCr) criterion; 34 were dialysed, and 21 died within 60 days after LT. Applying a cut-off value of 136 ng/ml, UNGAL values 6 h after surgery was a good predictor of AKI development within 7 days after surgery, having a positive predictive value (PPV) of 80% with an AUC of 0.76 (95% CI 0.67–0.86). PNGAL at 18 h after LT was also a good predictor of AKI in the first week, having a PPV of 81% and AUC of 0.74 (95% CI 0.60–0.88). Based on PNGAL and UNGAL cut-off criteria levels, time to AKI diagnosis was 28 and 23 h earlier than by sCr, respectively. The best times to assess the need for dialysis were 18 h after LT by PNGAL and 06 h after LT by UNGAL.

Conclusion

In conclusion, the plasma and urine NGAL elevation pattern in the perioperative period of the liver transplant can predict AKI diagnosis earlier. UNGAL was an early independent predictor of AKI development and need for dialysis. Further studies are needed to assess whether the clinical use of biomarkers can improve patient outcomes.

Trial registration

Registered at Clinical Trials (clinicaltrials.gov) in March 24th, 2014 by title “Acute Kidney Injury Biomarkers: Diagnosis and Application in Pre-operative Period of Liver Transplantation (AKIB)” and identifier NCT02095431, retrospectively registered.

rA1M-035, a Physicochemically Improved Human Recombinant α1-Microglobulin, Has Therapeutic Effects in Rhabdomyolysis-Induced Acute Kidney Injury

AIMS

Human α₁-microglobulin (A1M) is an endogenous reductase and radical- and heme-binding protein with physiological antioxidant protective functions. Recombinant human A1M (rA1M) has been shown to have therapeutic properties in animal models of preeclampsia, a pregnancy disease associated with oxidative stress. Recombinant A1M, however, lacks glycosylation, and shows lower solubility and stability than A1M purified from human plasma. The aims of this work were to (i) use site-directed mutagenesis to improve the physicochemical properties of rA1M, (ii) demonstrate that the physicochemically improved rA1M displays full in vitro cell protective effects as recombinant wild-type A1M (rA1M-wt), and (iii) show its therapeutic potential in vivo against acute kidney injury (AKI), another disease associated with oxidative stress.

RESULTS

A novel recombinant A1M-variant (rA1M-035) with three amino acid substitutions was constructed, successfully expressed, and purified. rA1M-035 had improved solubility and stability compared with rA1M-wt, and showed intact in vitro heme-binding, reductase, antioxidation, and cell protective activities. Both rA1M-035 and rA1M-wt showed, for the first time, potential in vivo protective effects on kidneys using a mouse rhabdomyolysis glycerol injection model of AKI.

INNOVATION

A novel recombinant A1M-variant, rA1M-035, was engineered. This protein showed improved solubility and stability compared with rA1M-wt, full in vitro functional activity, and potential protection against AKI in an in vivo rhabdomyolysis mouse model.

CONCLUSION

The new rA1M-035 is a better drug candidate than rA1M-wt for treatment of AKI and preeclampsia in human patients.

Intraoperative cell salvage with autologous transfusion in liver transplantation

Liver transplant (LT) is the primary treatment for patients with end-stage liver disease. About 25000 LTs are performed annually in the world. The potential for intraoperative bleeding is quite variable. However, massive bleeding is common and requires blood transfusion. Allogeneic blood transfusion has an immunosuppressive effect and an impact on recipient survival, in addition to the risk of transmission of viral infections and transfusion errors, among others. Techniques to prevent excessive bleeding or to use autologous blood have been proposed to minimize the negative effects of allogeneic blood transfusion. Intraoperative reinfusion of autologous blood is possible through previous self-donation or blood collected during the operation. However, LT does not normally allow autologous transfusion by prior self-donation. Hence, using autologous blood collected intraoperatively is the most feasible option. The use of intraoperative blood salvage autotransfusion (IBSA) minimizes the perioperative use of allogeneic blood, preventing negative transfusion effects without negatively impacting other clinical outcomes. The use of IBSA in patients with cancer is still a matter of debate due to the theoretical risk of reinfusion of tumor cells. However, studies have demonstrated the safety of IBSA in several surgical procedures, including LT for hepatocellular carcinoma. Considering the literature available to date, we can state that IBSA should be routinely used in LT, both in patients with cancer and in patients with benign diseases.

The System of Blood Coagulation in Normal and in Liver Transplantation (Review)

The review dwells on the problem of hemostatic disorders in patients undergoing liver transplantation and their correction in the perioperative period. The physiology of the hemostatic system, disorders of the blood coagulation system in patients at various stages of liver transplantation, correction of hemostatic disorders during and after orthotopic liver transplantation are discussed. Liver transplantation is performed in patients with liver diseases in the terminal stage of liver failure. At the same time, changes in the hemostatic system of these patients pose a significant risk of developing bleeding and/or thrombosis during and after liver transplantation. The hypothesis is suggested that the personalized correction of hemostasis disorder in liver transplantation should be based on considerating the nosological forms of the liver damage, mechanisms of development of recipient’s hemostatic disorders, and the stage of the surgery.

Early infections in the intensive care unit after liver transplantation-etiology and risk factors: A single-center experience

BACKGROUND

Infectious complications represent one of the main causes of perioperative morbidity and mortality of liver transplant recipients. The primary objective of this retrospective observational study was to evaluate incidence and etiology of early (within 1 month from surgery and occurring in the intensive care unit [ICU]) postoperative infections as well as donor- and recipient-related risk factors.

METHODS

The data of 280 patients undergoing 299 consecutive liver transplant procedures from January 2012 to December 2015 were extracted from the Italian ICU registry database and hospital registries. Perioperative risk factors, etiology of infections, and antibiotic susceptibility of isolated microorganisms were taken into consideration.

RESULTS

Global incidence of postoperative infections was 21%. Pneumonia was the most frequent infection and, globally, gram-negative bacteria were the most common agents. Septic shock was present in 22% of infection cases and hospital mortality was higher in patients with postoperative infection. Preoperative chronic obstructive pulmonary disease, malnutrition, preoperative ascites, encephalopathy, and early re-transplantation were significantly associated to post orthotopic LT infections.

CONCLUSION

Infections represent a major cause of early postoperative morbidity and mortality. The impact of single risk factors and the results of their preoperative management should be further investigated in order to reduce the incidence and evolution of postoperative infections.

Preoperative thrombelastography maximum amplitude predicts massive transfusion in liver transplantation

BACKGROUND

Massive transfusion (MT) is frequently required during liver transplantation. Risk stratification of transplant patients at risk for MT is an appealing concept but remains poorly developed. Thrombelastography (TEG) has recently been shown to reduce mortality when used for trauma resuscitation. We hypothesize that preoperative TEG can be used to risk stratify patients for MT.

MATERIAL AND METHODS

Liver transplant patients had blood drawn before surgical incision and assayed via TEG. Preoperative TEG measurements were collected in addition to standard laboratory coagulation tests. TEG variables including R-time (reaction time), angle, maximum amplitude (MA), and LY30 (clot lysis 30 min after MA) were correlated to red blood cell units, plasma (fresh frozen plasma), cryoprecipitate, and platelets during the first 24 h after surgery and tested for their performance using a receiver-operating characteristic curve.

RESULTS

Twenty-eight patients were included in the analysis with a median Model for End-Stage Liver Disease score of 17; 36% received a MT. The TEG variables associated with MT (defined as ≥10 red blood cell units/24 h) were a low MA (P < 0.001) and low angle (P = 0.014). A high international normalized ratio of prothrombin time (P = 0.003) and low platelet count (P = 0.007) were also associated with MT. MA had the highest area under the curve (0.861) followed by international normalized ratio of prothrombin time (0.803). An MA of less than 47 mm has a sensitivity of 90% and specificity of 72% to predict a MT. MA was the only coagulation variable that correlated strongly to all blood products transfused.

CONCLUSIONS

TEG MA has a high predictability of MT during liver transplantation. The use of TEG preoperatively may help guide more cost effective blood bank preparation for this procedure as only a third of patients required a MT.

Massive haemorrhage in liver transplantation: Consequences, prediction and management

From its inception the success of liver transplantation has been associated with massive blood loss. Massive transfusion is classically defined as > 10 units of red blood cells within 24 h, but describing transfusion rates over a shorter period of time may reduce the potential for survival bias. Both massive haemorrhage and transfusion are associated with increased risk of mortality and morbidity (need for dialysis/surgical site infection) following liver transplantation although causality is difficult to prove due to the observational design of most trials. The blood loss associated with liver transplantation is multifactorial. Portal hypertension secondary to cirrhosis results in extensive collateral circulation, which can bleed during hepatectomy particular if portal pressures are increased. Avoiding volume loading and maintenance of a low central venous pressure together with the use of vasopressors have been shown to reduce blood loss and transfusion during liver transplantation, but may increase the risk of renal impairment post-operatively. Coagulation defects may be present pre-transplant, but haemostasis is often re-balanced due to a deficit in both pro- and anti-coagulation factors. Further derangement of haemostasis may develop in the anhepatic and neohepatic phases due to absent hepatic metabolic function, hyperfibrinolysis and platelet sequestration in the donor liver. Point-of-care tests of coagulation such as the viscoelastic tests rotation thromboelastometry/thromboelastometry allow and more accurate and rapid assessment of these derangements in coagulation and guide the use of factor replacement and antifibrinolytics. Transfusion protocols guided by these tests have been shown to reduce transfusion rates compared with conventional coagulation tests, but have not shown improvements in mortality or morbidity. Pre-operative factors associated with massive transfusion include previous surgery, re-do transplantation, the aetiology and severity of liver disease. Intra-operatively the use of piggy-back technique and avoiding veno-veno bypass has been shown to reduced blood loss.