Risk factors for bleeding and clinical implications in patients undergoing liver transplantation

Four-factor Prothrombin Complex Concentrate During Liver Transplantation: A Retrospective Cohort Study

Background

Four-factor prothrombin complex concentrate (PCC) is a plasma product that contains factors II, VII, IX, X, protein C, and protein S. PCC can be used off-label to treat coagulopathy during orthotopic liver transplantation (OLT). However, its use comes with safety concerns regarding thrombosis. The purpose of our study is to determine the safety of PCC in OLT.

Methods

We conducted a retrospective cohort study of patients who received 4-factor PCC during OLT at our institution from January 1, 2018, to May 1, 2022, with a 1:1 match of 83 patients who received PCC and 83 patients who did not. We evaluated 30-d mortality, 1-y mortality, prevalence of thrombotic complications (portal vein thrombosis, deep venous thrombosis, myocardial infarction, and pulmonary embolus), and postoperative intensive care (ICU) length of stay (LOS).

Results

There was no significant difference in 30-d mortality (odds ratio [OR] 5; 95% confidence interval [CI], 0.58-42.8; P = 0.14), 1-y mortality (OR 3; 95% CI, 0.61-14.86; P = 0.18), or ICU LOS (OR -13.8; 95% CI, -39.2 to 11.6; P = 0.29). There was no increased incidence of thrombotic complications among patients receiving PCC 90 d after surgery, including portal vein thrombosis (OR 1.5; 95% CI, 0.42-5.32; P = 0.53), pulmonary embolus (OR 1; 95% CI, 0.14-7.1; P = 0.99), deep venous thrombosis (OR 0.67; 95% CI, 0.11-3.99; P = 0.66), and myocardial infarction (OR 1.67; 95% CI, 0.4-6.97; P = 0.48).

Conclusions

Although there was a statistically insignificant increase in mortality after PCC administration during OLT, we did not see a significant increase in perioperative complications, including thrombotic events and increased ICU LOS.

Selective Serotonin Reuptake Inhibitor (SSRI) Bleeding Risk: Considerations for the Consult-Liaison Psychiatrist

PURPOSE OF REVIEW

To present a clinically oriented review of selective serotonin reuptake inhibitor (SSRI)-related bleeding issues commonly addressed by consult-liaison psychiatrists.

RECENT FINDINGS

Concomitant medical, surgical, or hospital-based conditions exacerbate the risk of SSRI-related bleeding even though a review of the literature suggests it is only marginally elevated. Psychiatrists and other clinicians need to consider these conditions along with antidepressant benefits when answering the question: to start, hold, continue, or change the antidepressant? Where an evidence base is limited, mechanistic understanding may help consult-liaison psychiatrists navigate this terrain and collaborate with other medical specialties on responsible antidepressant management. Most often, the risk is cumulative; data are not directly applicable to complex clinical situations. This review incorporates a hematologic perspective and approach to bleeding risk assessment along with extant data on SSRI-induced bleeding risk ad specific medical conditions.

Coagulopathy and hemostasis management in patients undergoing liver transplantation: Defining a dynamic spectrum across phases of care

Patients with acute and chronic liver disease present with a wide range of disease states and severity that may require liver transplantation (LT). Physiologic alterations occur that are dynamic throughout all phases of perioperative care, creating complex management scenarios that necessitate multidisciplinary clinical care. Specifically, alterations in hemostasis in liver disease can be pronounced and evolve with disease progression over time. Recent studies and society guidance address this emerging paradigm and offer recommendations to assist with hemostatic management in patients with liver disease. However, patients undergoing LT are unique and diverse, often with unstable disease that requires specialized approaches. Our aim is to provide a focused review of hemostatic management of the LT patient, distinguish unique aspects of the three main phases of care (before LT, perioperative, and after LT), and identify knowledge gaps and critical areas of future research.

What is the optimal management of thromboprophylaxis after liver transplantation regarding prevention of bleeding, hepatic artery, or portal vein thrombosis? A systematic review of the literature and expert panel recommendations

BACKGROUND

A key tenet of clinical management of patients post liver transplantation (LT) is the prevention of thrombotic and bleeding complications. This systematic review investigated the optimal management of thromboprophylaxis after LT regarding portal vein thrombosis (PVT) or hepatic artery thrombosis (HAT) and prevention of bleeding.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Seven databases were used to conduct extensive literature searches focusing on the use of anticoagulation in LT and its impact on the following outcomes: PVT, HAT, and bleeding (CRD42021244288).

RESULTS

Of the 2478 articles/abstracts screened, 16 studies were included in the final review. All articles were critically appraised by a panel of independent reviewers. There was wide variation regarding the anticoagulation protocols used. Thromboprophylaxis with therapeutic doses of heparin/Vitamin K antagonist combination did not decrease the risk of de novo or the recurrence of PVT but was associated with an increased risk of bleeding in some studies. Only the use of aspirin resulted in a small but significant decrease in the incidence of HAT post-LT, yet it did not increase the risk of bleeding.

CONCLUSIONS

Based on existing data and expert opinion, thromboprophylaxis at therapeutic or prophylactic dose is not recommended for prevention of de novo PVT following LT in patients not at high risk. Aspirin should be considered as the standard of care following LT to prevent HAT. Thromboprophylaxis should be strongly considered in recipients at risk of HAT and PVT following LT.

The effect of a viscoelastic-guided bleeding algorithm implementation on blood products use in adult liver transplant patients. A propensity score-matched before-after study

BACKGROUND

Perioperative blood products transfusion is correlated with increased morbidity and mortality in liver transplantation (LTx). The objectives of our study are to assess the effect of a standardized viscoelastic test (VET)-guided bleeding management algorithm implementation on intraoperative bleeding, allogenic blood products and factor concentrates requirements and on early postoperative complications in LTx.

METHODS

Retrospective before-after study comparing two matched cohorts of patients undergoing LTx before (control cohort) and after (intervention cohort) the implementation of a VET-based bleeding algorithm in a single center academic hospital.

RESULTS

After propensity score matching, we included 94 patients in each cohort. Patients in intervention cohort received significantly less blood products, fresh frozen plasma (FFP), and cryoprecipitate (p < 0.001 for each), while the amount of fibrinogen concentrate used was significantly higher (p < 0.001). Postoperatively, intervention cohort patients had significantly lower postoperative hemoglobin and fibrinogen levels and longer prothrombin time compared to control cohort. There were no significant differences in red blood cells transfusions, intraoperative bleeding, early postoperative complications, and short term survival.

CONCLUSIONS

The implementation of a VET-guided bleeding algorithm decreases allogenic blood products requirements, mainly FFP use and allows a more restrictive management of coagulopathy in patients with chronic liver disease undergoing LTx.

Validation of McCluskey Index for Massive Blood Transfusion Prediction in Liver Transplantation

BACKGROUND

The McCluskey index has been used as a tool to predict massive bleeding (>6 red blood cells units) during orthotropic liver transplantation. The objective of this study is to verify its efficacy at our institution.

MATERIALS AND METHODS

Between May 1998 and December 2017, we performed 1216 orthotropic liver transplantations, of which 1016 had sufficient data registered with respect to hemoderivative transfusion. We divided these patients into groups based on the original study of McCluskey. This study was approved by the ethical committee of our Institution and was performed in accordance with the Declaration of Helsinki.

RESULTS

The mean Model for End-Stage Liver Disease score in the 4 groups was 7.5 (range, 7-8) for low risk; 13 (range, 3-32) for medium risk, 17 (range, 8-41) for high risk, and 25 (range, 11-36) for very high risk (P < .001). No significant differences were observed regarding body mass index or hospital stay. No differences have been found in the number of suboptimal donors among the groups. With respect to hemoderivative transfusions, we observed the following for red blood cells: 7 (range, 6-8) units for low risk; 5.5 (range, 0-74) for medium risk; 7 (range, 0-73) for high risk, and 12 (range, 5-30) for very high risk (P < .001) and transfusion of plasma: 12 (range, 10-15) units for low risk; 11 (range, 0-89) for medium risk; 14 (range, 0-76) for high risk, and 13 (range, 3-30) for very high risk (P = .001).

CONCLUSIONS

The McCluskey index is a good indicator of the risk of hemorrhage and hence the necessity of transfusion.

Procedure-related bleeding risk in patients with cirrhosis and severe thrombocytopenia

BACKGROUND

Gaps of knowledge still exist about the potential association between severe thrombocytopenia and increased risk of procedure-associated bleeding in patients with liver disease.

METHODS

In this narrative review, we aimed at examining the association between procedure-related bleeding risk and platelet count in patients with cirrhosis and severe thrombocytopenia in various settings. We updated to 2020 a previously conducted literature search using MEDLINE/PubMed and EMBASE. The search string included clinical studies, adult patients with chronic liver disease and thrombocytopenia undergoing invasive procedures, any interventions and comparators, and haemorrhagic events of any severity as outcome.

RESULTS

The literature search identified 1276 unique publications, and 15 studies met the inclusion criteria and were analysed together with those identified by the previous search. Most of the new studies included in our analysis did not assess the association between post-procedural bleeding risk and platelet count alone in patients with chronic liver disease. Furthermore, some results could have been biased by prophylactic platelet transfusions. A few studies found that severe thrombocytopenia may be predictive of bleeding following percutaneous liver biopsy, dental extractions, percutaneous ablation of liver tumours and endoscopic polypectomy.

CONCLUSIONS

Currently available literature cannot support definitive conclusions about the appropriate target platelet counts to improve the risk of bleeding in cirrhotic patients who underwent invasive procedures; moreover, it showed enormous variability in the use of prophylactic platelet transfusions.

Prediction of Important Factors for Bleeding in Liver Cirrhosis Disease Using Ensemble Data Mining Approach

The main motivation to conduct the study presented in this paper was the fact that due to the development of improved solutions for prediction risk of bleeding and thus a faster and more accurate diagnosis of complications in cirrhotic patients, mortality of cirrhosis patients caused by bleeding of varices fell at the turn in the 21th century. Due to this fact, an additional research in this field is needed. The objective of this paper is to develop one prediction model that determines most important factors for bleeding in liver cirrhosis, which is useful for diagnosis and future treatment of patients. To achieve this goal, authors proposed one ensemble data mining methodology, as the most modern in the field of prediction, for integrating on one new way the two most commonly used techniques in prediction, classification with precede attribute number reduction and multiple logistic regression for calibration. Method was evaluated in the study, which analyzed the occurrence of variceal bleeding for 96 patients from the Clinical Center of Nis, Serbia, using 29 data from clinical to the color Doppler. Obtained results showed that proposed method with such big number and different types of data demonstrates better characteristics than individual technique integrated into it.

Association between intraoperative rotational thromboelastometry or conventional coagulation tests and bleeding in liver transplantation: an observational exploratory study

INTRODUCTION

Liver transplantation is associated with major blood loss and transfusions. Our objective was to evaluate the association between coagulation results (rotational thromboelastometry (ROTEM) and conventional coagulation tests) and intraoperative bleeding or perioperative red blood cell (RBC) transfusions in liver transplantation.

METHODS

We measured ROTEM values and conventional coagulation tests at the beginning of surgery, after graft reperfusion and at the end of surgery. We did bivariate correlation and multivariable regression analyses to explore the association between test results and either intraoperative bleeding or perioperative RBC transfusions.

RESULTS

We enrolled 75 consecutive patients. Median [Q1-Q3] intraoperative blood loss was 1400 mL [675-2300] and 59% of patients did not receive any RBC transfusion either intraoperatively or postoperatively. In multivariable analyses, FIBTEM maximal clot firmness (MCF) measured at the beginning of surgery was associated with lower intraoperative blood loss (ß = -106 mL for each mm; 95% CI, -203 to -9 mL). Both a higher haemoglobin concentration (multiplicative factor = 0.89 for each g/L; 95% CI, 0.84 to 0.95) and FIBTEM MCF measured at the end of surgery (multiplicative factor = 0.68 for each mm; 95% CI, 0.48 to 0.95) were associated with fewer postoperative RBC transfusions.

CONCLUSION

FIBTEM MCF was strongly associated with intraoperative blood loss and postoperative transfusions while other coagulation results were not. This study might inform future clinical trials on ROTEM-based interventions in liver transplantation.

STUDY REGISTRATION

Clinical Trials.gov: NCT02356068.

Visceral adiposity is an independent risk factor for high intra-operative blood loss during living-donor liver transplantation; could preoperative rehabilitation and nutritional therapy mitigate that risk?

BACKGROUND & AIMS

Blood loss during liver transplantation (LT) is one of the major concerns of the transplant team, given the potential negative post-transplant outcomes related to it. Blood loss was reported to be higher in certain body compositions, such as obese patients, undergoing LT. Therefore, we aimed to study the risk factors for high blood loss (HBL) during adult living donor liver transplant (ALDLT) including the body composition markers; visceral-to-subcutaneous adipose tissue area ratio (VSR), skeletal muscle index and intramuscular adipose tissue content. In June 2015, an aggressive perioperative rehabilitation and nutritional therapy (APRNT) program was prescribed in our institute for the patients with abnormal body composition.

METHODS

We retrospectively analyzed 394 patients who had undergone their first ALDLT between 2006 and 2019. Risk factors for HBL were analyzed in the total cohort. Differences in blood loss and risk factors were analyzed in relation to the APRNT.

RESULTS

Multivariate risk factor analysis in the total cohort showed that a high VSR (odds ratio (OR): 1.98, 95% confidence interval (CI): 1.19-3.29, P = 0.009), was an independent risk factor for HBL during ALDLT, as well as a history of upper abdominal surgery, simultaneous splenectomy and the presence of a large amount of ascites. After the introduction of the APRNT, a significantly lower blood loss was observed during the ALDLT recipient operation (P = 0.003). Moreover, the significant difference in blood loss observed between normal and high VSR groups before the application of the APRNT (P < 0.001), was not observed with the APRNT (P = 0.85). Likewise, before the APRNT, only high VSR was a risk factor for HBL by multivariate analysis (OR: 2.34, CI: 1.33-4.09, P = 0.003). Whereas with the APRNT, high VSR was no longer a significant risk factor for HBL even by univariate analysis (OR: 0.89, CI: 0.26-3.12, P = 0.86).

CONCLUSION

Increased visceral adiposity was an independent risk factor for high intraoperative blood loss during ALDLT recipient operation. With APRNT, high VSR was not associated with high blood loss. Therefore, APRNT might have mitigated the risk of high blood loss related to high visceral adiposity.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Intraoperative blood loss and transfusion during primary pediatric liver transplantation: A single-center experience

Children undergoing liver transplantation are at a significant risk for intraoperative hemorrhage and thrombotic complications, we aim to identify novel risk factors for massive intraoperative blood loss and transfusion in PLT recipients and describe its impact on graft survival and hospital LOS. We reviewed all primary PLTs performed at our institution between September 2007 and September 2016. Data are presented as n (%) or median (interquartile range). EBL was standardized by weight. Massive EBL and MT were defined as greater than the 85th percentile of the cohort. 250 transplantations were performed during the study period. 38 (15%) recipients had massive EBL, and LOS was 31.5 (15-58) days compared to 11 (7-21) days among those without massive EBL (P < 0.001). MT median LOS was 34 (14-59) days compared to 11 (7-21) days among those without MT (P = 0.001). Upon backward stepwise regression, technical variant graft, operative time, and transfusion of FFP, platelet, and/or cryoprecipitate were significant independent risk factors for massive EBL and MT, while admission from home was a protective factor. Recipient weight was a significant independent risk factor for MT alone. Massive EBL and MT were not statistically significant for overall graft survival. MT was, however, a significant risk factor for 30-day graft loss. PLT recipients with massive EBL or MT had significantly longer LOS and increased 30-day graft loss in patients who required MT. We identified longer operative time and technical variant graft were significant independent risk factors for massive EBL and MT, while being admitted from home was a protective factor.

Utility of prothrombin complex concentrate as first-line treatment modality of coagulopathy in patients undergoing liver transplantation: A propensity score-matched study

BACKGROUND

Transfusion management during liver transplantation (LT) is aimed at reducing blood loss and allogeneic transfusion requirements. Although prothrombin complex concentrate (PCC) has been used satisfactorily in various bleeding disorders, studies on its safety, and efficacy during LT are limited.

METHODS

A retrospective chart review of adult patients who underwent living donor LT at a single institute between October 2016 and January 2018 was carried out. The safety and efficacy of PCC in reducing transfusion requirements intraoperatively in patients who received PCC were compared with patients who did not receive PCC. A propensity score-matching technique was used, at a 1:1 ratio, to remove selection bias.

RESULTS

After completing the 1:1 propensity score-matched analysis, 60 pairs of patients were identified. The use of PCC was associated with significantly decreased red blood cell transfusion requirements (6.2 ± 4.1 vs 8.23 ± 5.18, P < 0.001) and fresh frozen plasma transfusion requirements (2.6 ± 2 vs 6.18 ± 4.1, P < 0.001). The number of patients developing postoperative hemorrhagic complications was higher in the non-PCC group.

CONCLUSIONS

During LT, the use of PCC led to decreased transfusion requirements. No thromboembolic complications related to PCC were noted in this series.

Effects of perioperative fluid management on postoperative outcomes in liver transplantation: a systematic review protocol

BACKGROUND

Liver transplant recipients suffer many complications, but few intraoperative interventions supported by high-quality evidence have been found effective to reduce their incidence or severity. Fluid balance has been proposed as an important aspect of perioperative care in high-risk recipients. We will conduct a systematic review aimed at evaluating the effects of restrictive perioperative fluid management strategies compared to liberal ones on clinically significant postoperative outcomes.

METHODS

We will search through major databases (CINAHL Complete, EMB Reviews, EMBASE, MEDLINE, PubMed, and the gray literature (CADTH, Clinical Trials, National Guideline Clearing House, NICE, MedNar, Google Scholar and Open Grey)), from inception up to a date close to the review submission for publication, for eligible studies. Randomized controlled trials and comparative non-randomized studies (prospective or retrospective) comparing two fluid management strategies (or two outcomes with available data on fluid volume received for observational studies) on adult liver recipients will be included. Eligible studies will have to report at least one postoperative complication or mortality. Our primary outcome will be acute renal failure and our secondary exploratory outcomes will be all other postoperative complications and mortality. Study selection and data abstraction using an electronic standardized form will be performed by three authors. Risk of bias will be evaluated and data will be pooled if limited clinical diversity is observed.

DISCUSSION

Human organs available for transplantation are scarce resources. Strategies to improve recipients' survival are needed. We hypothesize that restrictive fluid management strategies will be associated with better postoperative outcomes than liberal fluid management strategies. This systematic review will improve our understanding of the available evidence and help us better inform future clinical trials.

SYSTEMATIC REVIEW REGISTRATION

This systematic review protocol is registered in PROSPERO ( CRD42017054970 ).

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.

Pretransplant predictors of early mortality in adult recipients of liver transplantation in the MELD-Na Era

AIMS

To identify pretransplant predictors of early mortality (90 days after transplantation) and evaluate their discriminating capacity in adult liver transplant recipients (LTR).

DESIGN

An observational, retrospective, nested cases-controls study from a consecutive cohort of LTRs was carried out.

SETTING

University hospital.

PATIENTS

All consecutive LTR between January 2003 and December 2016 were eligible for inclusion. Patients with acute liver failure, previous graft dysfunction, simultaneous multiple organ transplantation, non-heart beating donors, and those needing urgent retransplantation during the study period were excluded. The analysis comprised 471 patients.

MAIN VARIABLES OF INTEREST

Pretransplant characteristics were the main variables of interest. The LTR were grouped according to the dependent variable (early mortality). Multivariate logistic regression analysis was conducted to identify predictors of early mortality. The discriminating capacity of the models obtained was evaluated by comparing ROC curves (models versus MELD-Na).

RESULTS

The MELD-Na score (OR = 1.069, 95% CI = 1.014-1.127), age > 60 years (OR = 2.479, 95% CI = 1.226-5.015), and LTR height < 163cm (OR = 4.092, 95% CI = 2.115-7.917) were identified as independent predictors of early mortality. The cause of transplantation (hepatocellular carcinoma or decompensated cirrhosis) was identified as a confounding factor.

CONCLUSIONS

In LTR due to decompensated cirrhosis, the MELD-Na score, age > 60 years, and height < 163cm are independent predictors of early mortality. These factors provide a better classification model than the MELD-Na score for early post-transplant mortality.

A data-driven patient blood management strategy in liver transplantation

BACKGROUND AND OBJECTIVES

Blood utilization during liver transplant has decreased, but remains highly variable due to many complex surgical and physiologic factors. Previous models attempted to predict utilization using preoperative variables to stratify cases into two usage groups, usually using entire blood units for measurement. We sought to develop a practical predictive model using specific transfusion volumes (in ml) to develop a data-driven patient blood management strategy.

MATERIALS AND METHODS

This is a retrospective evaluation of primary liver transplants at a single institution from 2013 to 2015. Multivariable analysis of preoperative recipient and donor factors was used to develop a model predictive of intraoperative red-blood-cell (pRBC) use.

RESULTS

Of 256 adult liver transplants, 207 patients had complete transfusion volume data for analysis. The median intraoperative allogeneic pRBC transfusion volume was 1250 ml, and the average was 1563 ± 1543 ml. Preoperative haemoglobin, spontaneous bacterial peritonitis, preoperative haemodialysis and preoperative international normalized ratio together yielded the strongest model predicting pRBC usage. When it predicted <1250 ml of pRBCs, all cases with 0 ml transfused were captured and only 8·6% of the time >1250 ml were used. This prediction had a sensitivity of 0·91 and a specificity of 0·89. If predicted usage was >2000 ml, 75% of the time blood loss exceeded 2000 ml.

CONCLUSION

Patients likely to require low or high pRBC transfusion volumes were identified with excellent accuracy using this predictive model at our institution. This model may help predict bleeding risk for each patient and facilitate optimized blood ordering.

Low Platelet Counts and Prolonged Prothrombin Time Early After Operation Predict the 90 Days Morbidity and Mortality in Living-donor Liver Transplantation

OBJECTIVE

The aim of the study was to investigate the association between platelet count/prothrombin time early after transplant and short-term outcomes among living-donor liver transplant (LDLT) recipients.

BACKGROUND

Postoperative platelet count and prothrombin time-international normalized ratio (PT-INR) were critical biomarkers in LDLT.

METHODS

The study participants consisted of 445 initial LDLT recipients, and perioperative variables, including platelet count and PT-INR, were assessed for their association with severe complications (Clavien-Dindo classification grade IIIb/IV) and mortality within 90 days after operation.

RESULTS

Severe complications and operative mortality occurred in 161 (36%) and 23 patients (5%), respectively. Cox regression analysis revealed that a high body mass index [hazard ratio (HR) 1.2; 95% confidence interval (CI), 1.1-1.4; P = 0.004] and low platelet count on postoperative day (POD)3 (HR 0.88; 95% CI, 0.57-0.97; P < 0.001) were independent predictors for grade IIIb/IV complications after LDLT, whereas high PT-INR on POD5 (HR 1.1; 95% CI, 1.1-1.3; P = 0.021) was the only independent factor for operative mortality. In addtion, the progonostic scoring with low platelet count (<50 × 10/L) and prolonged prothrombin time (PT-INR >1.6) within POD5, 1 point for each, was demonstrated to be useful in predicting the development of Clavien-Dindo grade IIIb/IV/V complications after LDLT (30% for score 0, 46% for score 1, and 72% for score 2: 0 vs 1, P = 0.004; 0 vs 2, P < 0.001; 1 vs 2, P = 0.002).

CONCLUSIONS

PT-INR above 1.6 and platelet count below 50 × 10/L within POD5 were useful predictors of mortality and severe complications after LDLT.

Hemophilia Liver Transplantation Observational Study

Hepatitis C virus (HCV) infection is the leading cause of liver disease in hemophilia patients. In those with human immunodeficiency virus (HIV)/HCV coinfection, the rate of liver disease progression is greater than in HCV monoinfected individuals. Despite antiretroviral therapy, which slows HCV liver disease progression, some require transplantation. Whether transplant outcomes are worse in hemophilic (H) rather than nonhemophilic (NH) candidates is unknown. In order to determine rates and predictors of pretransplant and posttransplant survival, we conducted a retrospective observational study using United Network for Organ Sharing national transplant registry data, comparing HCV+ H and NH candidates. We identified 2502 HCV+ liver transplant candidates from 8 US university-based transplant centers, between January 1, 2004 to December 31, 2010, including 144 HIV+ (6%) and 2358 HIV-; 36 H (1%) and 2466 NH; 1213 (48%) transplanted and 1289 not transplanted. Other than male predominance and younger age, each were P < 0.001. Baseline data were comparable between H and NH. In univariate analysis, 90-day pretransplant mortality was associated with higher baseline Model for End-Stage Liver Disease (MELD; hazard ratio [HR] = 1.15; P < 0.001), lower baseline platelet count (HR = 0.9 per 25,000/µL; P = 0.04), and having HIV/HCV+ hemophilia (P = 0.003). In multivariate analysis, pretransplant mortality was associated with higher MELD (P < 0.001) and was significantly greater in HIV+ than HIV- groups (P = 0.001). However, it did not differ between HIV+ H and NH (HR = 1.7; P = 0.36). Among HIV/HCV+, posttransplant mortality was similar between H and NH, despite lower CD4 in H (P = 0.04). In conclusion, this observational study confirms that hemophilia per se does not have a specific influence on transplant outcomes and that HIV infection increases the risk of mortality in both H and NH patients. Liver Transplantation 23 762-768 2017 AASLD.

Preoperative risk factors for intra-operative bleeding in pediatric liver transplantation

This study analyzes the preoperative risk factors for intra-operative bleeding in our recent series of pediatric LTs. Between November 2009 and November 2014, 84 consecutive isolated pediatric LTs were performed in 81 children. Potential preoperative predictive factors for bleeding, amount of intra-operative transfusions, postoperative course, and outcome were recorded. Cutoff point for intra-operative HBL was defined as intra-operative RBC transfusions ≥1 TBV. Twenty-six patients (31%) had intra-operative HBL. One-year patient survival after LT was 66.7% (CI 95%=[50.2-88.5]) in HBL patients and 83.8% (CI 95%=[74.6-94.1]) in the others (P=.054). Among 13 potential preoperative risk factors, three of them were identified as independent predictors of high intra-operative bleeding: abdominal surgical procedure(s) prior to LT, factor V level ≤30% before transplantation, and ex situ parenchymal transsection of the liver graft. Based on these findings, we propose a simple score to predict the individual hemorrhagic risk related to each patient and graft association. This score may help to better anticipate intra-operative bleeding and improve patient's management.

Thromboelastographic reference ranges for a cirrhotic patient population undergoing liver transplantation

AIM

To describe the thromboelastography (TEG) “reference” values within a population of liver transplant (LT) candidates that underline the differences from healthy patients.

METHODS

Between 2000 and 2013, 261 liver transplant patients with a model for end-stage liver disease (MELD) score between 15 and 40 were studied. In particular the adult patients (aged 18-70 years) underwent to a first LT with a MELD score between 15 and 40 were included, while all patients with acute liver failure, congenital bleeding disorders, and anticoagulant and/or antiplatelet drug use were excluded. In this population of cirrhotic patients, preoperative haematological and coagulation laboratory tests were collected, and the pretransplant thromboelastographic parameters were studied and compared with the parameters measured in a previously studied population of 40 healthy subjects. The basal TEG parameters analysed in the cirrhotic population of liver candidates were as follows: Reaction time (r), coagulation time (k), Angle-Rate of polymerization of clot (αAngle), Maximum strenght of clot (MA), Amplitudes of the TEG tracing at 30 min and 60 min after MA is measured (A30 and A60), and Fibrinolysis at 30 and 60 min after MA (Ly30 and Ly60). The possible correlation between the distribution of the reference range and the gender, age, MELD score (higher or lower than 20) and indications for transplantation (liver pathology) were also investigated. In particular, a MELD cut-off value of 20 was chosen to verify the possible correlation between the thromboelastographic reference range and MELD score.

RESULTS

Most of the TEG reference values from patients with end-stage liver disease were significantly different from those measured in the healthy population and were outside the suggested normal ranges in up to 79.3% of subjects. Wide differences were found among all TEG variables, including r (41.5% of the values), k (48.6%), α (43.7%), MA (79.3%), A30 (74.4%) and A60 (80.9%), indicating a prevailing trend to hypocoagulability. The differences between the mean TEG values obtained from healthy subjects and the cirrhotic population were statistically significant for r (P = 0.039), k (P < 0.001), MA (P < 0.001), A30 (P < 0.001), A60 (P < 0.001) and Ly60 (P = 0.038), indicating slower and less stable clot formation in the cirrhotic patients. In the cirrhotic population, 9.5% of patients had an r value shorter than normal, indicating a tendency for faster clot formation. Within the cirrhotic patient population, gender, age and the presence of hepatocellular carcinoma or alcoholic cirrhosis were not significantly associated with greater clot firmness or enhanced whole blood clot formation, whereas greater clot strength was associated with a MELD score < 20, hepatitis C virus and cholestatic-related cirrhosis (P < 0.001; P = 0.013; P < 0.001).

CONCLUSION

The range and distribution of TEG values in cirrhotic patients differ from those of healthy subjects, suggesting that a specific thromboelastographic reference range is required for liver transplant candidates.

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.

Hemostatic balance in patients with liver cirrhosis: Report of a consensus conference

Patients with cirrhosis present with hemostatic alterations secondary to reduced availability of pro-coagulant and anti-coagulant factors. The net effect of these changes is a rebalanced hemostatic system. The Italian Association of the Study of the Liver (AISF) and the Italian Society of Internal Medicine (SIMI) promoted a consensus conference on the hemostatic balance in patients with cirrhosis. The consensus process started with the review of the literature by a scientific board of experts and ended with a formal consensus meeting in Rome in December 2014. The statements were graded according to quality of evidence and strength of recommendations, and approved by an independent jury. The statements presented here highlight strengths and weaknesses of current laboratory tests to assess bleeding and thrombotic risk in cirrhotic patients, the pathophysiology of hemostatic perturbations in this condition, and outline the optimal management of bleeding and thrombosis in patients with liver cirrhosis.

Temporary abdominal closure and delayed biliary reconstruction due to massive bleeding in patients undergoing liver transplantation: an old trick in a new indication

Background

Massive bleeding during liver transplantation (LT) is difficult to manage surgical event. Perihepatic packing (PP) and temporary abdominal closure (TAC) with delayed biliary reconstruction (DBR) can be applied in these circumstances.

Method

A prospective database of LT in a major transplant center was analyzed to identify patients with massive uncontrollable bleeding during LT that was resolved by PP, TAC, and DBR.

Results

From January 2009 to July 2013, 20 (3.6%) of 547 patients who underwent LT underwent DBR. Mean intraoperative blood loss was 20,500 ml at the first operation. The DBR was performed with a mean of 55.2 h (16–110) after LT. Biliary reconstruction included duct‐to‐duct (n = 9) and hepatico‐jejunostomy (n = 11). Complications occurred in eight patients and included portal vein thrombosis, cholangitis, severe bacteremia, pneumonia. There was one in‐hospital death. In the follow‐up of 18 to 33 months we have seen one patient died 9 months after transplantation. The remaining 18 patients are alive and well.

Conclusions

In case of massive uncontrollable bleeding and bowel edema during LT, the combined procedures of PP, TAC, and DBR offer an alternatively surgical option to solve the tough situation.

Reducing transfusion requirements in liver transplantation

Liver transplantation (LT) was historically associated with massive blood loss and transfusion. Over the past two decades transfusion requirements have reduced dramatically and increasingly transfusion-free transplantation is a reality. Both bleeding and transfusion are associated with adverse outcomes in LT. Minimising bleeding and reducing unnecessary transfusions are therefore key goals in the perioperative period. As the understanding of the causes of bleeding has evolved so too have techniques to minimize or reduce the impact of blood loss. Surgical “piggyback” techniques, anaesthetic low central venous pressure and haemodilution strategies and the use of autologous cell salvage, point of care monitoring and targeted correction of coagulopathy, particularly through use of factor concentrates, have all contributed to declining reliance on allogenic blood products. Pre-emptive management of preoperative anaemia and adoption of more restrictive transfusion thresholds is increasingly common as patient blood management (PBM) gains momentum. Despite progress, increasing use of marginal grafts and transplantation of sicker recipients will continue to present new challenges in bleeding and transfusion management. Variation in practice across different centres and within the literature demonstrates the current lack of clear transfusion guidance. In this article we summarise the causes and predictors of bleeding and present the evidence for a variety of PBM strategies in LT.

Risk Factors Associated with Reoperation for Bleeding following Liver Transplantation

Introduction. This study's objective was to identify risk factors associated with reoperation for bleeding following liver transplantation (LTx). Methods. A retrospective study was performed at a single institution between 2001 and 2012. Operative reports were used to identify patients who underwent reoperation for bleeding within 2 weeks following LTx (operations for nonbleeding etiologies were excluded). Results. Reoperation for bleeding was observed in 101/928 (10.8%) of LTx patients. The following characteristics were associated with reoperation on multivariable analysis: recipient MELD score (OR 1.06/MELD unit, 95% CI 1.03, 1.09), number of platelets transfused (OR 0.73/platelet unit, 95% CI 0.58, 0.91), and aminocaproic acid utilization (OR 0.46, 95% CI 0.27, 0.80). LTx patients who underwent reoperation for bleeding had a longer ICU stay (5 days ± 7 versus 2 days ± 3, P < 0.001) and hospitalization (18 days ± 9 versus 10 days ± 18, P < 0.001). The risk of death increased in patients who underwent reoperation for bleeding (HR 1.89, 95% CI 1.26, 2.85). Conclusion. Reoperation for bleeding following LTx was associated with increased resource utilization and recipient mortality. A lower threshold for intraoperative platelet transfusion and antifibrinolytics, especially in patients with high lab-MELD score, may decrease the incidence of reoperation for bleeding following LTx.

Hyper- and hypometabolism are not related to nutritional status of patients on the waiting list for liver transplantation

BACKGROUND & AIMS

Metabolic disorders and malnutrition are well known conditions reported in patients with liver disease (LD), but the relationship between them are underexplored. So, the aim of this study was to assess the resting energy expenditure (REE) of these patients, identifying the prevalence of hyper- and hypometabolism. In addition, to evaluate whether malnutrition and clinical variables were associated with REE and metabolic disorders.

METHODS

The REE was measured by indirect calorimetry and predicted by the Harris and Benedict formula (REEHB). Nutritional status was assessed by different methods. The etiology, severity and complications of LD were also evaluated.

RESULTS

A total of 81 patients were assessed. The measured REE was 1587.5 ± 426.6 kcal. The REE was overestimated by the REEHB (REE:REEHB <0.8) in 7.4% and underestimated (REE:REEHB >1.2) in 24.7% of the patients. The REE was lower in malnourished patients (p < 0.05). However, hyper- and hypometabolism were not associated with nutritional status (p > 0.05). The REE and hypermetabolism were not associated with LD, but hypometabolic patients had a higher prevalence of Child C, and had higher values for MELD, INR and total bilirubin (p < 0.05). After multiple regression analyses, the REE was significantly associated (p < 0.05) with intracellular body water, arm muscle area and serum glucose. Serum glucose was only significantly associated (p < 0.05) with hypermetabolism, and INR with hypometabolism.

CONCLUSION

Changes in resting metabolism are present but not universal. The hypermetabolism was associated with extrahepatic factors, and hypometabolism with the severity of LD. Under these conditions in the clinical setting, calculated energy requirements using the HB formula should be adjusted.

Prothrombin complex concentrate in the reduction of blood loss during orthotopic liver transplantation: PROTON-trial

BACKGROUND

In patients with cirrhosis, the synthesis of coagulation factors can fall short, reflected by a prolonged prothrombin time. Although anticoagulants factors are decreased as well, blood loss during orthotopic liver transplantation can still be excessive. Blood loss during orthotopic liver transplantation is currently managed by transfusion of red blood cell concentrates, platelet concentrates, fresh frozen plasma, and fibrinogen concentrate. Transfusion of these products may paradoxically result in an increased bleeding tendency due to aggravated portal hypertension. The hemostatic effect of these products may therefore be overshadowed by bleeding complications due to volume overload.In contrast to these transfusion products, prothrombin complex concentrate is a low-volume highly purified concentrate, containing the four vitamin K dependent coagulation factors. Previous studies have suggested that administration of prothrombin complex concentrate is an effective method to normalize a prolonged prothrombin time in patients with liver cirrhosis. We aim to investigate whether the pre-operative administration of prothrombin complex concentrate in patients undergoing liver transplantation for end-stage liver cirrhosis, is a safe and effective method to reduce perioperative blood loss and transfusion requirements.

METHODS/DESIGN

This is a double blind, multicenter, placebo-controlled randomized trial.Cirrhotic patients with a prolonged INR (≥1.5) undergoing liver transplantation will be randomized between placebo or prothrombin complex concentrate administration prior to surgery. Demographic, surgical and transfusion data will be recorded. The primary outcome of this study is RBC transfusion requirements.

DISCUSSION

Patients with advanced cirrhosis have reduced plasma levels of both pro- and anticoagulant coagulation proteins. Prothrombin complex concentrate is a low-volume plasma product that contains both procoagulant and anticoagulant proteins and transfusion will not affect the volume status prior to the surgical procedure. We hypothesize that administration of prothrombin complex concentrate will result in a reduction of perioperative blood loss and transfusion requirements. Theoretically, the administration of prothrombin complex concentrate may be associated with a higher risk of thromboembolic complications. Therefore, thromboembolic complications are an important secondary endpoint and the occurrence of this type of complication will be closely monitored during the study.

TRIAL REGISTRATION

The trial is registered at http://www.trialregister.nl with number NTR3174. This registry is accepted by the ICMJE.