Rebalanced hemostasis in patients with liver disease: evidence and clinical consequences. Blood. 2010;116:878-885. [PMID: 20400681 DOI: 10.1182/blood-2010-02-261891]

Use of four-factor prothrombin complex concentrate in the reversal of warfarin-induced and nonvitamin K antagonist-related coagulopathy

: To evaluate the efficacy of international normalized ratio (INR) reversal using four-factor prothrombin complex concentrate (4F-PCC) in nonmedication-induced coagulopathy. We performed a single-site, retrospective cohort study of patients receiving off-label use of 4F-PCC. Cohorts included liver dysfunction if they had acute liver decompensation or cirrhosis without other causative factors of liver failure such as sepsis, coagulopathy of acute sepsis (CAS) if they had documentation of sepsis and no underlying liver disorder, known factor deficiencies, or medication-induced coagulopathy, or warfarin if they were taking warfarin. Patients with unknown medication or direct oral anticoagulant usage were excluded. 4F-PCC was administered 32 times in 26 patients for nonvitamin-K antagonist related coagulopathy (11 CAS and 21 liver dysfunction) and 47 administrations were in warfarin patients. Liver dysfunction patients had a mean model for end-stage liver disease score of 28 ± 10. CAS and warfarin patients had significant INR reductions (ΔINR 1.9, P < 0.01; ΔINR 3.9, P < 0.01, respectively). Liver dysfunction patients mean change in INR trended toward significance (ΔINR 0.7, P = 0.09). Patients who received 4F-PCC based upon previously established dosing guidelines for moderate elevations in INR (20-30 IU/kg) doing demonstrated similar reductions in INR between CAS and warfarin patients (ΔINR 1.3, P = 0.03, ΔINR 1.0 P < 0.01, respectively). 4F-PCC significantly reduces the INR in CAS patients and trended toward significant reductions in liver dysfunction patients. Adequately powered, prospective trials are needed to demonstrate 4F-PCC efficacy in reversal of these coagulopathies.

Platelet-leucocyte aggregation is augmented in cirrhosis and further increased by platelet transfusion

BACKGROUND

Thrombocytopenia and circulating dysfunctional immune cells are commonly observed in patients with cirrhosis. Platelets may form complexes with neutrophils, monocytes and T cells modulating their function. We recently reported increased frequencies of platelet-complexed neutrophils in cirrhosis with evidence of neutrophil activation upon contact with healthy platelets in vitro. Whether this occurs in vivo following platelet transfusion and contributes to systemic inflammation and endothelial activation is unknown.

AIMS

To characterise platelet-leucocyte aggregation in cirrhosis and to determine whether elective platelet transfusion results in perturbations associated with changes in markers of haemostasis, inflammation or endothelial activation.

METHODS

We collected blood from cirrhotics (n = 19) before and following elective platelet transfusion. We measured platelet-leucocyte aggregation, activation and function, and markers of platelet activation, systemic inflammation and endothelial activation by flow cytometry. Haemostasis was assessed by thromboelastometry and plasma haemostatic proteins.

RESULTS

We observed a 2.5-fold increase in platelet-complexed neutrophils in patients with cirrhosis compared with healthy subjects and twofold more platelets attached per monocyte and T cell. All platelet-complexed leucocytes expressed higher levels of activation markers and platelet-complexed neutrophils had higher resting oxidative burst and phagocytic capacity than their nonplatelet-complexed counterparts (P < 0.001); most pronounced in patients with cirrhosis. Paradoxically, platelet-complexed leucocyte frequency decreased with increasing MELD score. Platelet transfusion increased soluble CD40 ligand (platelet activation marker), the frequency of platelet-complexed monocytes (P < 0.05) and improved haemostatic status.

CONCLUSION

Cirrhotic patients have activated circulating platelet-complexed leucocytes with increased platelet-monocyte aggregation following elective platelet transfusion. Elective platelet transfusion might therefore exacerbate immune dysfunction in cirrhosis.

Plasminogen Activator Inhibitor-1 Reduces Tissue-Type Plasminogen Activator-Dependent Fibrinolysis and Intrahepatic Hemorrhage in Experimental Acetaminophen Overdose

Acetaminophen (APAP)-induced liver injury in mice is associated with activation of the coagulation cascade and deposition of fibrin in liver. Plasminogen activator inhibitor-1 (PAI-1) is an important physiological inhibitor of tissue-type plasminogen activator (tPA) and plays a critical role in fibrinolysis. PAI-1 expression is increased in both experimental APAP-induced liver injury and patients with acute liver failure. Prior studies have shown that PAI-1 prevents intrahepatic hemorrhage and mortality after APAP challenge, but the downstream mechanisms are not clear. We tested the hypothesis that PAI-1 limits liver-related morbidity after APAP challenge by reducing tPA-dependent fibrinolysis. Compared with APAP-challenged (300 mg/kg) wild-type mice, hepatic deposition of cross-linked fibrin was reduced, with intrahepatic congestion and hemorrhage increased in PAI-1-deficient mice 24 hours after APAP overdose. Administration of recombinant wild-type human PAI-1 reduced intrahepatic hemorrhage 24 hours after APAP challenge in PAI-1-/- mice, whereas a mutant PAI-1 lacking antiprotease function had no effect. Of interest, tPA deficiency alone did not affect APAP-induced liver damage. In contrast, fibrinolysis, intrahepatic congestion and hemorrhage, and mortality driven by PAI-1 deficiency were reduced in APAP-treated tPA-/-/PAI-1-/- double-knockout mice. The results identify PAI-1 as a critical regulator of intrahepatic fibrinolysis in experimental liver injury. Moreover, the results suggest that the balance between PAI-1 and tPA activity is an important determinant of liver pathology after APAP overdose.

Bleeding and thrombotic complications of pediatric liver transplant

BACKGROUND

Pediatric patients undergoing liver transplant are at significant risk for bleeding and thrombotic complications due to the complex nature of rebalanced hemostasis in patients with liver disease.

METHODS/OBJECTIVES

We reviewed records of 92 pediatric liver and multivisceral transplant cases at Duke University Medical Center between January 2009 and December 2015. The goal was to define the nature and incidence of bleeding and thrombotic complications in this cohort and define potential risk factors.

RESULTS

There were 24 major bleeding events in 19 transplants (incidence 20.7%) and 30 thrombotic events in 23 transplants (incidence 25%). Five of the 10 retransplantations were for vascular thrombotic complications. Thirty-day mortality was 4.9%, and three of these four deaths were due to vascular thrombosis. No bleeding events led to retransplantation or mortality. Prophylactic aspirin was associated with decreased risk of thrombosis without increased bleeding. Prophylactic heparin did not increase bleeding risk. Laboratory assays predicted events poorly, apparently failing to capture the nuanced and dynamic interplay between pro- and anticoagulant factors in the posttransplant patient.

CONCLUSIONS

Both bleeding and thrombosis are frequent in this population, but only thrombotic complications contributed to retransplantation and mortality. A standardized approach to coagulation testing and antithrombotic therapy may be useful in predicting and reducing adverse outcomes. Alternative approaches to monitoring hemostasis need to be prospectively investigated in this complex patient population.

Perioperative management of liver surgery-review on pathophysiology of liver disease and liver failure

An increasing number of patients present for liver surgery. Given the complex pathophysiological changes in chronic liver disease (CLD), it is pivotal to understand the fundamentals of chronic and acute liver failure. This review will give an overview on related organ dysfunction as well as recommendations for perioperative management and treatment of liver failure-related symptoms.

Structural changes of fibrinogen as a consequence of cirrhosis

Cirrhosis is a disease which may develop as a consequence of various conditions. In advanced liver disease, blood coagulation can be seriously affected. Portal hypertension, vascular abnormalities and/or a dysbalance in coagulation factors may result in bleeding disorders or in the development of thrombosis. Fibrinogen is the main protein involved in clot formation and wound healing. The aim of this work was to analyse the glycosylation pattern of the isolated fibrinogen molecules by lectin-based protein microarray, together with the carbonylation pattern of the individual fibrinogen chains, possible changes in the molecular secondary and tertiary structure and reactivity with the insulin-like growth factor-binding protein 1 (IGFBP-1) in patients with cirrhosis. The results pointed to an increase in several carbohydrate moieties: tri/tetra-antennary structures, Gal β-1,4 GlcNAc, terminal α-2,3 Sia and α-1,3 Man, and a decrease in core α-1,6 Fuc and bi-antennary galactosylated N-glycans with bisecting GlcNAc. Fibrinogen Aα chain was the most susceptible to carbonylation, followed by the Bβ chain. Cirrhosis induced additional protein carbonylation, mostly on the α chain. Spectrofluorimetry and CD spectrometry detected reduction in the α-helix content, protein unfolding and/or appearance of modified amino acid residues in cirrhosis. The amount of complexes which fibrinogen forms with IGFBP-1, another factor involved in wound healing was significantly greater in patients with cirrhosis than in healthy individuals. A more detailed knowledge of individual molecules in coagulation process may contribute to deeper understanding of coagulopathies and the results of this study offer additional information on the possible mechanisms involved in impaired coagulation due to cirrhosis.

Intensive Care Management of Patients with Cirrhosis

PURPOSE OF REVIEW

Cirrhosis is a major worldwide health problem which results in a high level of morbidity and mortality. Patients with cirrhosis who require intensive care support have high mortality rates of near 50%. The goal of this review is to address the management of common complications of cirrhosis in the ICU.

RECENT FINDINGS

Recent epidemiological studies have shown an increase in hospitalizations due to advanced liver disease with an associated increase in intensive care utilization. Given an increasing burden on the healthcare system, it is imperative that we strive to improve our management cirrhotic patients in the intensive care unit. Large studies evaluating the management of patients in the intensive care setting are lacking. To date, most recommendations are based on extrapolation of data from studies in cirrhosis outside of the ICU or by applying general critical care principles which may or may not be appropriate for the critically ill cirrhotic patient. Future research is required to answer important management questions.

K time & maximum amplitude of thromboelastogram predict post-central venous cannulation bleeding in patients with cirrhosis: A pilot study

Background & objectives:

Coagulation and haemostasis are dynamic processes. The haemostatic changes in liver disease affect all aspects of coagulation. The prothrombin time (PT)/international normalized ratio (INR) was developed to monitor oral anticoagulant therapy and the activated partial thromboplastin time to investigate inheritable single factor deficiencies. Viscoelastic tests such as thromboelastogram (TEG) give information about dynamics of clot formation (coagulation factor and anticoagulant activity), clot strength (platelets and fibrinogen) and clot stability (finbrinolysis and factor XIII). Administration of blood products before invasive procedures is still guided by INR and platelet count in patients of liver disease. This study was aimed to evaluate the validity of TEG to predict post-procedural bleed after central venous cannulation in patients with cirrhosis.

Methods:

Ninety patients aged 20-70 yr diagnosed with liver cirrhosis requiring elective central venous catheter (CVC) insertion were studied. Platelet count, INR, serum creatinine, TEG and Child-Turcotte-Pugh (CTP) score were recorded before the procedure. Right-sided internal jugular vein was cannulated. On the basis of presence or absence of post-procedural bleed, patients were divided into bleeding and non-bleeding groups. The CTP score, component of TEG (R - reaction time, K - coagulation time, MA - maximum amplitude and α - angle) and laboratory parameters of both the groups were compared.

Results:

Bleeding was seen more when CTP scores were ≥10 (P=0.05). The K time of 3.05 min or more on thromboelastograph was a significant predictor of bleeding [area under the curve (AUC) 0.694, P=0.047]. MA of 48.8 mm or more was a significant predictor of non-bleeding. INR ≥2.6 was a significant predictor of bleeding (AUC 0.765, P=0.005). K time had a low-positive predictive value of 20 per cent and the positive and negative likelihood ratios of 1.87 and 0.48, respectively.

Interpretation & conclusions:

Our results show that the cut-off value for INR ≥2.6 and K time ≥3.05 min predict bleeding and MA ≥48.8 mm predicts non-bleeding in patients with cirrhosis undergoing central venous pressure catheter cannulation.

Increased risk of venous thromboembolism in hospitalized patients with cirrhosis due to non-alcoholic steatohepatitis

Objective

Patients with cirrhosis are at increased risk for venous thromboembolism (VTE) and portal vein thrombosis (PVT). Cirrhosis due to non-alcoholic steatohepatitis (NASH) appears to be particularly prothrombotic. We investigated hospitalized patients with NASH cirrhosis to determine if they are at increased risk for VTE.

Methods

Data on adult hospitalized patients with cirrhosis and VTE (deep vein thrombosis and/or pulmonary embolism) between November 1, 2010 and December 31, 2015 were obtained. Cases with VTE were matched by age, gender, and model for end stage liver disease (MELD) score to corresponding controls without VTE.

Results

Two hundred and ninety subjects (145 matched pairs) with mean age of 58.4 ± 11.8 years and MELD score of 16.0 ± 7.2 were included. Baseline characteristics were similar between cases and controls. Independent adjusted risk factors for VTE included NASH (OR: 2.46, 95% CI: 1.07–5.65, p = 0.034), prior VTE (OR: 7.12, 95% CI: 1.99–25.5, p = 0.003), and presence of PVT (OR: 2.18, 95% CI: 1.03–4.58, p = 0.041). Thrombocytopenia was associated with decreased risk (OR: 0.49, 95% CI: 0.26–0.95, p = 0.035).

Conclusions

NASH is an independent risk factor for VTE among cirrhosis patients and provides further evidence that NASH is a hypercoagulable state. While all hospitalized patients with cirrhosis at risk for VTE should be considered for medical thromboprophylaxis, those with NASH cirrhosis are at particularly increased risk and therefore a high index of suspicion for VTE should be maintained even in the presence of thromboprophylaxis.

Platelet Count Does Not Predict Bleeding in Cirrhotic Patients: Results from the PRO-LIVER Study

OBJECTIVES

Thrombocytopenia is a hallmark for patients with cirrhosis and it is perceived as a risk factor for bleeding events. However, the relationship between platelet count and bleeding is still unclear.

METHODS

We investigated the relationship between platelet count and major or clinical relevant nonmajor bleedings during a follow-up of ∼4 years.

RESULTS

A total of 280 cirrhotic patients with different degrees of liver disease (67% males; age 64±37 years; 47% Child-Pugh B and C) were followed up for a median of 1,129 (interquartile range: 800-1,498) days yielding 953.12 patient-year of observation. The annual rate of any significant bleeding was 5.45%/year (3.57%/year and 1.89%/year for major and minor bleeding, respectively). Fifty-two (18.6%) patients experienced a major (n=34) or minor (n=18) bleeding event, predominantly from gastrointestinal origin. Platelet counts progressively decreased with the worsening of liver disease and were similar in patients with or without major or minor bleeding: a platelet count ≤50 × 103/μl was detected in 3 (6%) patients with and in 20 (9%) patients without any bleeding event. Conversely, prothrombin time-international normalized ratio was slightly higher in patients with overall or major bleeding. On Cox proportional hazard analysis, only a previous gastrointestinal bleeding (hazard ratio (HR): 1.96; 95% confidence interval: 1.11-3.47; P=0.020) and encephalopathy (HR: 2.05; 95% confidence interval: 1.16-3.62; P=0.013) independently predicted overall bleeding events.

CONCLUSIONS

Platelet count does not predict unprovoked major or minor bleeding in cirrhotic patients.

Coagulopathy in Zellweger spectrum disorders: a role for vitamin K

INTRODUCTION

Zellweger spectrum disorders (ZSDs) are caused by an impairment of peroxisome biogenesis, resulting in multiple metabolic abnormalities. This leads to a range of symptoms, including hepatic dysfunction and coagulopathy. This study evaluated the incidence and severity of coagulopathy and the effect of vitamin K supplementation orally and IV in ZSD.

METHODS

Data were retrospectively retrieved from the medical records of 30 ZSD patients to study coagulopathy and the effect of vitamin K orally on proteins induced by vitamin K absence (PIVKA-II) levels. Five patients from the cohort with a prolonged prothrombin time, low factor VII, and elevated PIVKA-II levels received 10 mg of vitamin K IV. Laboratory results, including thrombin generation, at baseline and 72 h after vitamin K administration were examined.

RESULTS

In the retrospective cohort, four patients (13.3%) experienced intracranial bleedings and 14 (46.7%) reported minor bleeding. No thrombotic events occurred. PIVKA-II levels decreased 38% after start of vitamin K therapy orally. In the five patients with a coagulopathy, despite treatment with oral administration of vitamin K, vitamin K IV caused an additional decrease (23%) of PIVKA-II levels and increased thrombin generation.

CONCLUSION

Bleeding complications frequently occur in ZSD patients due to liver disease and vitamin K deficiency. Vitamin K deficiency is partly corrected by vitamin K supplementation orally, and vitamin K administered IV additionally improves vitamin K status, as shown by further decrease of PIVKA-II and improved thrombin generation.

Platelets as Modulators of Liver Diseases

Platelets are key players in thrombosis and hemostasis. Alterations in platelet count and function are common in liver disease, and may contribute to bleeding or thrombotic complications in liver diseases and during liver surgery. In addition to their hemostatic function, platelets may modulate liver diseases by mechanisms that are incompletely understood. Here, we present clinical evidence for a role of platelets in the progression of chronic and acute liver diseases, including cirrhosis, acute liver failure, and hepatocellular carcinoma. We also present clinical evidence that platelets promote liver regeneration following partial liver resection. Subsequently, we summarize studies in experimental animal models that support these clinical observations, and also highlight studies that are in contrast with clinical observations. The combined results of clinical and experimental studies suggest that platelets may be a therapeutic target in the treatment of liver injury and repair, but the gaps in our understanding of mechanisms involved in platelet-mediated modulation of liver diseases call for caution in clinical application of these findings.

How I treat disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) is a condition characterized by systemic activation of coagulation, potentially leading to thrombotic obstruction of small and midsize vessels, thereby contributing to organ dysfunction. At the same time, ongoing consumption of platelets and coagulation proteins results in thrombocytopenia and low concentrations of clotting factors, which may cause profuse hemorrhagic complications. DIC is always secondary to an underlying condition, such as severe infections, solid or hematologic malignancies, trauma, or obstetric calamities. A reliable diagnosis of DIC can be made through simple scoring algorithms based on readily available routine hemostatic parameters. The cornerstone of supportive treatment of this coagulopathy is management of the underlying condition. Additionally, administration of heparin may be useful, and restoration of physiological anticoagulants has been suggested, but has not been proven successful in improving clinically relevant outcomes so far. In patients with major bleeding or at risk for hemorrhagic complications, administration of platelet concentrates, plasma, or coagulation factor concentrates should be considered.

Position of the French Working Group on Perioperative Haemostasis (GIHP) on viscoelastic tests: What role for which indication in bleeding situations?

PURPOSE

Viscoelastic tests (VETs), thromboelastography (TEG^®) and thromboelastometry (ROTEM^®) are global tests of coagulation performed on whole blood. They evaluate the mechanical strength of a clot as it builds and develops after coagulation itself. The time required to obtain haemostasis results remains a major problem for clinicians dealing with bleeding, although some teams have developed a rapid laboratory response strategy. Indeed, the value of rapid point-of-care diagnostic devices such as VETs has increased over the years. However, VETs are not standardised and there are few recommendations from the learned societies regarding their use. In 2014, the recommendations of the International Society of Thrombosis and Haemostasis (ISTH) only concerned haemophilia. The French Working Group on Perioperative haemostasis (GIHP) therefore proposes to summarise knowledge on the clinical use of these techniques in the setting of emergency and perioperative medicine.

METHODS

A review of the literature.

PRINCIPAL FINDINGS

The role of the VETs seems established in the management of severe trauma and in cardiac surgery, both adult and paediatric. In other situations, their role remains to be defined: hepatic transplantation, postpartum haemorrhage, and non-cardiac surgery. They must be part of the global management of haemostasis based on algorithms defined in each centre and for each population of patients. Their position at the bedside or in the laboratory is a matter of discussion between clinicians and biologists.

CONCLUSION

VETs must be included in algorithms. In consultation with the biology laboratory, these devices should be situated according to the way each centre functions.

Predicting early outcomes of liver transplantation in young children: The EARLY study

AIM

To determine potentially modifiable predictors of early outcomes after liver transplantation in children of age < 3 years.

METHODS

This study was a retrospective chart review including all consecutive children of age less than 3-years-old having had a liver transplant done at the Western Canadian referral center from June 2005 to June 2015. Pre-specified potential predictor variables and primary and secondary outcomes were recorded using standard definitions and a case report form. Associations between potential predictor variables and outcomes were determined using univariate and multiple logistic [odds ratio (OR); 95%CI] or linear (effect size, ES; 95%CI) regressions.

RESULTS

There were 65 children, of mean age 11.9 (SD 7.1) mo and weight 8.5 (2.1) kg, with biliary-atresia in 40 (62%), who had a living related donor [LRD; 29 (45%)], split/reduced [21 (32%)] or whole liver graft [15 (23%)]. Outcomes after liver transplant included: ventilator-days of 12.5 (14.1); pediatric intensive care unit mortality of 5 (8%); re-operation in 33 (51%), hepatic artery thrombosis (HAT) in 12 (19%), portal vein thrombosis (PVT) in 11 (17%), and any severe complication (HAT, PVT, bile leak, bowel perforation, intraabdominal infection, retransplant, or death) in 32 (49%) patients. Predictors of the prespecified primary outcomes on multiple regression were: (1) HAT: split/reduced (OR 0.06; 0.01, 0.76; P = 0.030) or LRD (OR 0.16; 0.03, 0.95; P = 0.044) vs whole liver graft; and (2) ventilator-days: surgeon (P < 0.05), lowest antithrombin (AT) postoperative day 2-5 (ES -0.24; -0.47, -0.02; P = 0.034), and split/reduced (ES -12.5; -21.8, -3.2; P = 0.009) vs whole-liver graft. Predictors of the pre-specified secondary outcomes on multiple regression were: (1) any thrombosis: LRD (OR 0.10; 0.01, 0.71; P = 0.021) or split/reduced (OR 0.10; 0.01, 0.85; P = 0.034) vs whole liver graft, and lowest AT postoperative day 2-5 (OR 0.93; 0.87, 0.99; P = 0.038); and (2) any severe complication: surgeon (P < 0.05), lowest AT postoperative day 2-5 (OR 0.92; 0.86-0.98; P = 0.016), and split/reduced (OR 0.06; 0.01, 0.78; P = 0.032) vs whole-liver graft.

CONCLUSION

In young children, whole liver graft and surgeon was associated with more complications, and higher AT postoperative day 2-5 was associated with fewer complications early after liver transplantation.

Platelets, inflammation and tissue regeneration

Blood platelets have long been recognised to bring about primary haemostasis with deficiencies in platelet production and function manifesting in bleeding while upregulated function favourises arterial thrombosis. Yet increasing evidence indicates that platelets fulfil a much wider role in health and disease. First, they store and release a wide range of biologically active substances including the panoply of growth factors, chemokines and cytokines released from α-granules. Membrane budding gives rise to microparticles (MPs), another active participant within the blood stream. Platelets are essential for the innate immune response and combat infection (viruses, bacteria, micro-organisms). They help maintain and modulate inflammation and are a major source of pro-inflammatory molecules (e.g. P-selectin, tissue factor, CD40L, metalloproteinases). As well as promoting coagulation, they are active in fibrinolysis; wound healing, angiogenesis and bone formation as well as in maternal tissue and foetal vascular remodelling. Activated platelets and MPs intervene in the propagation of major diseases. They are major players in atherosclerosis and related diseases, pathologies of the central nervous system (Alzheimers disease, multiple sclerosis), cancer and tumour growth. They participate in other tissue-related acquired pathologies such as skin diseases and allergy, rheumatoid arthritis, liver disease; while, paradoxically, autologous platelet-rich plasma and platelet releasate are being used as an aid to promote tissue repair and cellular growth. The above mentioned roles of platelets are now discussed.

Coagulopathy in Children With Liver Disease

It was thought that a high international normalized ratio predicted bleeding in patients with chronic liver disease (CLD) and patients were "autoanticoagulated." Contrary to this belief, while patients with CLD experienced bleeding, they also developed thromboses. In the last decade, the prevailing literature challenged the idea that an elevated international normalized ratio increased bleeding risk. The global assays of coagulation such as thromboelastography (TEG)/rotational thromboelastometry and thrombin generation assays provide additional insight into coagulation processes. It has become apparent that a parallel reduction of procoagulant and anticoagulant factors leave patients in a new "balanced" state, albeit a fragile one, where the balance can be easily disrupted. The inherent differences in coagulation between children and adults such as differences in levels of procoagulant and anticoagulant factors, underlying liver disease, and the paucity of studies in children make extrapolation of these findings to the pediatric population problematic. Ultimately, this is an area that requires further investigation to avoid inappropriate use of blood products and medication.

Thromboelastography for Assessing the Risk of Bleeding in Patients With Cirrhosis-Moving Closer

BACKGROUND AND AIMS

Conventional coagulation tests (CCTs) in patients with cirrhosis only assess procoagulant factors and are poor predictors of bleeding risk. In spite of this knowledge, they are routinely used prior to invasive procedures, and attempts are made to correct these abnormalities before invasive procedures. These practices are not supported by the evidence and are harmful to the patients.

METHODS

This prospective study included 150 patients of cirrhosis undergoing invasive procedures. CCTs [bleeding time (BT), clotting time (CT), international normalized ratio (INR), activated partial thromboplastin time (aPTT) and platelet count], thromboplastin generation time (TGT) and thromboelastography (TEG) were done in all patients, and they were observed for post procedural bleeding. None of the patients received prophylactic transfusion before the procedure.

RESULTS

BT, CT and TGT were normal in all 150 patients. One of 150 patients developed clinically significant post procedural bleeding. No statistically significant association was seen among INR, aPTT, platelet count and Child class with bleeding. TEG values (R time and MA value) were normal in 61% and 75% patients respectively in spite of abnormal CCTs in most of them. Comparison of abnormal TEG values (R time and MA value) with INR and platelet count, respectively, in patients with no bleeding showed a statistically significant lower percentage of abnormal values of R time and MA value compared to INR and platelet count.

CONCLUSION

Abnormal CCTs in patients of cirrhosis do not predict bleeding risk. TEG may be useful in patients undergoing invasive procedures to assess bleeding risk and prevents erroneous prophylactic transfusions.

The risk of venous thromboembolism in patients with hepatitis C

Some studies suggest that patients with hepatitis C virus (HCV) infection have an increased risk of deep venous thrombosis (DVT) and pulmonary embolism (PE). Unfortunately, available data on this association are contrasting. A systematic review and meta-analysis of literature studies was performed to evaluate the risk of venous thromboembolism (VTE) associated with HCV. Studies reporting on VTE risk associated with HCV were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. Six studies (10 data-sets) showed a significantly increased VTE risk in 100,364 HCV patients as compared with 8,471,176 uninfected controls (odds ratio [OR]: 1.900; 95 % confidence interval [CI]: 1.406, 2.570; p<0.0001). These results were confirmed when specifically considering the risk of DVT (6 studies, OR: 1.918; 95 %CI: 1.351, 2.723; p<0.0001), whereas a trend towards an increased risk of PE was documented in HCV patients (4 studies, OR: 1.811; 95 %CI: 0.895, 3.663; p=0.099). The increased VTE risk associated with HCV infection was consistently confirmed when analysing four studies reporting adjusted risk estimates (OR: 1.876; 95 %CI: 1.326, 2.654; P<0.0001), and after excluding studies specifically enrolling populations exposed to transient risk factors for VTE (4 studies, OR: 1.493; 95 %CI: 1.167, 1.910; p=0.001). Meta-regression models suggested that age and male gender may significantly impact on the risk of VTE associated with HCV-positivity. Results of our metaanalysis suggest that HCV-infected subjects may exhibit an increased risk of VTE. However, further high quality studies are needed to extend and confirm our findings.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Prothrombotic State in a Patient With Acute Liver Failure: The Question of Anticoagulation

A 35-year-old male with acute liver failure due to acute hepatitis B virus infection was admitted to the intensive care unit with significant hepatocellular injury, cholestasis, abnormal standard coagulation tests, normal rotational thromboelastometry indices, and without signs of bleeding. He underwent emergency liver transplantation without requiring blood product transfusions or procoagulant treatments. The postoperative course was complicated by deep vein thrombosis and impending hepatic artery thrombosis treated with unfractionated heparin, aspirin, and intravenous prostacyclin. The patient survived and made a full neurological recovery. This case revealed the presence of a prothrombotic state due to a rebalanced coagulation system in a patient with liver dysfunction that was not identifiable by standard coagulation tests. This case emphasizes that identifying and treating coagulopathy is very difficult in liver failure patients and requires specific diagnostic and therapeutic strategies.

Viscoelastic Monitoring to Guide Hemostatic Resuscitation in Liver Transplantation Surgery

Coagulopathic bleeding must be anticipated during liver transplantation (LT) surgery. Patients with end-stage liver disease (ESLD) often present with disease-related hematologic disturbances, including the loss of hepatic procoagulant and anticoagulant clotting factors and thrombocytopenia. Transplantation surgery itself presents additional hemostatic changes, including hyperfibrinolysis. Viscoelastic monitoring (VEM) is often used to provide targeted, personalized hemostatic therapies for complex bleeding states including cardiac surgery and major trauma. The use in these coagulopathic conditions led to its application to LT, although the mechanisms of coagulopathy in these patients are quite different. While VEM is often used during transplant surgeries in Europe and North America, evidence supporting its use is limited to a few small clinical studies. The theoretical and clinical applications of the standard and specialized VEM assays are discussed in the setting of LT and ESLD.

Coagulation Management During Liver Transplantation: Use of Fibrinogen Concentrate, Recombinant Activated Factor VII, Prothrombin Complex Concentrate, and Antifibrinolytics

Coagulation management, and transfusion practice in liver transplantation (LT) have been evolving in the recent years due to better understanding of coagulation abnormalities in end-stage liver disease, and clinical management of LT patients. Avoidance of allogeneic blood components is feasible in some patients, but multi-modal coagulation therapies may be necessary in others who develop complex coagulopathy due to hemorrhage, hemodilution, hypothermia, and acid-base disturbances. Transfusions of plasma and cryoprecipitate remain to be the mainstay therapy for procoagulant factor replacement during LT. Clinical efficacy and safety of these products are limited by logistic issues (eg, thawing), and mostly noninfectious complications. Considering potential alternatives to conventional transfusion is thus important to improve hemostatic resuscitation in complex LT cases. The present review is mainly focused on procoagulant properties of plasma and platelet transfusion, and currently available plasma-derived and recombinant factor concentrates, and antifibrinolytic agents in LT patients. The role of viscoelastic coagulation tests to guide specific component therapies will be also discussed.

Critical care management of the patient with cirrhosis awaiting liver transplant in the intensive care unit

Patients with cirrhosis who are awaiting liver transplantation (LT) are at high risk for developing critical illnesses. Current liver allocation policies that dictate a "sickest first" approach coupled with a mismatch between need and availability of organs result in longer wait times, and thus, patients are becoming increasingly ill while awaiting organ transplantation. Even patients with well-compensated cirrhosis may suffer acute deterioration; the syndrome of acute-on-chronic liver failure (ACLF) results in multisystem organ dysfunction and a marked increase in associated short-term morbidity and mortality. For patients on transplant waiting lists, the development of multisystem organ failure may eliminate candidacy for transplant by virtue of being "too sick" to safely undergo transplantation surgery. The goals of intensive care management of patients suffering ACLF are to rapidly recognize and treat inciting events (eg, infection and bleeding) and to aggressively support failing organ systems to ensure that patients may successfully undergo LT. Management of the critically ill ACLF patient awaiting transplantation is best accomplished by multidisciplinary teams with expertise in critical care and transplant medicine. Such teams are well suited to address the needs of this unique patient population and to identify patients who may be too ill to proceed to transplantation surgery. The focus of this review is to identify the common complications of ACLF and to describe our approach management in critically ill patients awaiting LT in our centers. Liver Transplantation 23 1465-1476 2017 AASLD.

Transfusion-Related Acute Lung Injury (TRALI) and Transfusion-Associated Circulatory Overload (TACO) in Liver Transplantation: A Case Report and Focused Review

Liver transplantation (LT) is a complex procedure in a patient with multi-organ system dysfunction and coagulation defects. The surgical procedure involves dissection, major vessel manipulation, and pathophysiologic effects of graft storage and reperfusion. As a result, LT frequently involves significant hemorrhage. Subsequent massive transfusion carries high risk of transfusion-associated complications. Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are the leading causes of transfusion associated mortality. In this case report and focused review, we present data that suggest that patients undergoing liver transplantation may be at higher risk for TRALI and TACO than the general population. Anesthesiologists can play a role in decreasing these risks by increasing recognition and reporting of TRALI and TACO, using point of care testing with thromboelastography to guide and decrease transfusion, and considering alternatives to traditional blood products like solvent/detergent plasma.

Anesthetic Management for Prolonged Incidental Surgery in Advanced Liver Disease

In spite of advances in perioperative management, operative procedures in patients with chronic liver disease pose a significant challenge for the anesthesiologist due to multisystem involvement, high risk of postoperative hepatic decompensation, and mortality. We describe the anesthetic management of an elderly patient with advanced liver disease (model for end-stage liver disease 16) for prolonged abdominal surgery. The use of invasive hemodynamic monitoring, point-of-care biochemical, and hematological surveillance coupled with prompt correction of all abnormalities was responsible for good outcome. The patient's inguinal swellings turned out to be extensions of a large peritoneal mesothelioma, necessitating a large abdominal incision and blood loss. Analgesia was provided by bilateral transversus abdominis plane blocks, which helped to reduce opioid use and rapid extubation.

Pathogenesis, prevention, and management of bleeding and thrombosis in patients with liver diseases

Patients with liver diseases may develop alterations in all components of the hemostatic system. Thrombocytopenia, low levels of coagulation factors and inhibitors, low levels of fibrinolytic proteins, and increased levels of endothelial-derived proteins such as von Willebrand factor are all part of the coagulopathy of liver disease. Due to concomitant changes in pro- and antihemostatic drivers, the net effects of these complex hemostatic changes have long been unclear. According to current concepts, the hemostatic system of patients with liver disease is in an unstable balance, which explains the occurrence of both bleeding and thrombotic complications. This review will discuss etiology and management of bleeding and thrombosis in liver disease and will outline unsolved clinical questions. In addition, we will discuss the role of intrahepatic activation of coagulation for progression of liver disease, a novel paradigm with potential consequences for the general management of patients with liver disease.

Reduced platelet activation and platelet aggregation in patients with alcoholic liver cirrhosis

Results from previous studies regarding platelet function in liver cirrhosis are discordant. The aim was to investigate platelet activation and platelet aggregation in patients with alcoholic liver cirrhosis. We included 27 patients with alcoholic liver cirrhosis and 22 healthy individuals. A recently established flow cytometric approach was used to measure platelet activation and platelet aggregation independent of sample platelet count. Platelet aggregation was further investigated using light transmission aggregometry (LTA) (for platelet count >100 × 10⁹/L). Platelet agonists were adenosine diphosphate, thrombin receptor-activating peptide, arachidonic acid, collagen, and collagen-related peptide. Patients had lower median platelet count than healthy individuals, 125 × 10⁹/L (interquartile range [IQR] 90-185) versus 240 × 10⁹ (IQR 204-285), p < 0.001. Platelet activation levels in stimulated samples were lower in patients versus healthy individuals, e.g., after collagen-related peptide stimulation, the median percentage of platelets positive for activated glycoprotein IIb/IIIa was 85% (IQR 70-94) in patients versus 97% (IQR 94-99) in healthy individuals, p < 0.001; lower platelet activation capacity being associated with low platelet count and Child-Pugh class B/C cirrhosis. Flow cytometric platelet aggregation was reduced in patients for collagen-related peptide and for adenosine diphosphate, e.g., platelet aggregation (mean ± standard deviation) was 57% ± 4 in patients versus 70% ± 1 in healthy individuals for collagen-related peptide, p = 0.01. Light LTA showed reduced collagen-induced platelet aggregation in some patients compared with healthy individuals. In conclusion, platelet function was reduced in some patients with alcoholic liver cirrhosis and the severity was associated with platelet count and severity of liver cirrhosis.

Anesthesia for Liver Transplantation

The provision of anesthesia for a liver transplant program requires a dedicated team of anesthesiologists. Liver transplant anesthesiologists must have an understanding of liver physiology and anatomy; the spectrum of clinical disease associated with liver dysfunction; the impact of warm and cold ischemia times, surgical techniques in liver transplantation, and the impact of ischemia-reperfusion syndrome; and optimal practices to protect the liver. The team must provide a 24-hour service, be actively involved in the selection committee process, and stay current with advances in the subspecialty.

Balanced haemostasis with both hypo- and hyper-coagulable features in critically ill patients with acute-on-chronic-liver failure

BACKGROUND

Cirrhotic patients have complex haemostatic abnormalities. Current evidence suggests stable cirrhotic (SC) patients have a "re-balanced" haemostatic state. However, limited data exists in acute decompensated (AD) or acute on chronic liver failure (ACLF) patients.

METHODS

We utilised thrombin generation analysis, fibrinolysis assessment, and evaluation of haemostatic parameters to assess haemostasis in liver disease of progressive severity.

RESULTS

The study cohorts were comprised of: SC, n=8; AD n=44; ACLF, n=17; and Healthy Control (HC), n=35. There was a progressive increase across the cohorts in INR (p=0.0001), Factor VIII (p=0.0001) and VWF levels (p=0.0001) and a correspondingly decrease in anti-thrombin (p=0.0001), ADAMTS-13 (p=0.01) and fibrinogen levels (p=0.0001). In the presence of thrombomodulin, thrombin generation was equivalent or significantly higher in all the cohorts compared to HC (p=0.0001). Compared to AD, ACLF had a lower ETP (p=0.002) and thrombin peak (p=0.0001). There was no significant difference across the cohorts in clot lysis time (p=0.07), although compared to HC, AD had a significantly shorter lysis time (p=0.001).

CONCLUSIONS

Our cohorts, despite significant differences in haemostatic parameters, displayed intact thrombin generation but progressive hypo-functional clot stability and potentially but not universal hyper-functional haemostasis.

Prophylactic Plasma Transfusion Is Not Associated With Decreased Red Blood Cell Requirements in Critically Ill Patients

BACKGROUND

Critically ill patients frequently receive plasma transfusion under the assumptions that abnormal coagulation test results confer increased risk of bleeding and that plasma transfusion will decrease this risk. However, the effect of prophylactic plasma transfusion remains poorly understood. The objective of this study was to determine the relationship between prophylactic plasma transfusion and bleeding complications in critically ill patients.

METHODS

This is a retrospective cohort study of adults admitted to the intensive care unit (ICU) at a single academic institution between January 1, 2009 and December 31, 2013. Inclusion criteria included age ≥18 years and an international normalized ratio measured during ICU admission. Multivariable propensity-matched analyses were used to evaluate associations between prophylactic plasma transfusion and outcomes of interest with a primary outcome of red blood cell transfusion in the ensuing 24 hours and secondary outcomes of hospital- and ICU-free days and mortality within 30 days of ICU discharge.

RESULTS

A total of 27,561 patients were included in the investigation with 2472 (9.0%) receiving plasma therapy and 1105 (44.7%) for which plasma transfusion was prophylactic in nature. In multivariable propensity-matched analyses, patients receiving plasma had higher rates of red blood cell transfusion (odds ratio: 4.3 [95% confidence interval: 3.3-5.7], P < .001) and fewer hospital-free days (estimated % increase: -11.0% [95% confidence interval: -11.4, -10.6%], P < .001). There were no significant differences in ICU-free days or mortality. These findings appeared robust, persisting in multiple predefined sensitivity analyses.

CONCLUSIONS

Prophylactic administration of plasma in the critically ill was not associated with improved clinical outcomes. Further investigation examining the utility of plasma transfusion in this population is warranted.

African Americans have a lower prevalence of portal vein thrombosis at the time of liver transplantation

BACKGROUND

Perioperative vascular thrombotic events in patients undergoing liver transplantation (LT) are associated with significant morbidity and mortality.

METHODS

In this retrospective UNOS database analysis, we evaluated the prevalence of portal vein thrombosis (PVT) and factors contributing to PVT development in different ethnic groups.

RESULTS

Of the 47 953 LT performed between 2002 and 2015, we identified 3642 cases of PVT. African Americans (AA) had a significantly lower prevalence of PVT compared to other ethnic groups (p = 0.0001). Multivariable regression analysis confirmed that AA were less likely than other ethnicities to have PVT (OR = 0.6). AA cohort was more likely to have infectious or autoimmune causes of liver failure (OR = 1.6, 1.7 respectively) as well as higher creatinine and INR compared to other groups (OR = 1.6, 1.3 respectively). AA's were less likely to have encephalopathy, ascites, or variceal bleeding, which might indicate lower portal pressures. AA's were listed for LT later than other ethnicities and had both a lower functional status and higher MELD score at the time of registration.

DISCUSSION

AA's had a significantly lower prevalence of preoperative PVT despite having a greater number of factors predisposing to thrombosis. This predisposition should be considered before instituting perioperative antithrombotic therapy.

Hematological Issues in Liver Disease

Acute and chronic liver failure are associated with numerous alterations in different features of the coagulation system. Consequently, there is widespread confusion regarding the potential for both bleeding and thrombosis in patients with liver disease. The risk of bleeding is related to the hemodynamic changes in portal pressures and venous congestion whereas the thrombotic risk stems from changes in the coagulation system. Antithrombotic prophylaxis and treatment of patients with hemorrhage and thrombosis requires careful assessment, interpretation of laboratory workup, and attention to coexistent morbidities. A framework for the management of these conditions is presented for clinicians.

Thromboelastometry: Relation to the severity of liver cirrhosis in patients considered for liver transplantation

The severity of liver disease is assessed by scoring systems, which include the conventional coagulation test prothrombin time-the international normalized ratio (PT-INR). However, PT-INR is not predictive of bleeding in liver disease and thromboelastometry (ROTEM) has been suggested to give a better overview of the coagulation system in these patients. It has now been suggested that coagulation as reflected by tromboelastomety may also be used for prognostic purposes. The objective of our study was to investigate whether thrombelastometry may discriminate the degree of liver insufficiency according to the scoring systems Child Pugh and Model for End-stage Liver Disease (MELD).Forty patients with chronic liver disease of different etiologies and stages were included in this observational cross-sectional study. The severity of liver disease was evaluated using the Child-Pugh score and the MELD score, and blood samples for biochemistry, conventional coagulation tests, and ROTEM were collected at the time of the final assessment for liver transplantation. Statistical comparisons for the studied parameters with scores of severity were made using Spearman correlation test and receiver-operating characteristic (ROC) curves.Spearman correlation coefficients indicated that the thromboelastometric parameters did not correlate with Child-Pugh or MELD scores. The ROC curves of the thromboelastometric parameters could not differentiate advanced stages from early stages of liver cirrhosis.Standard ROTEM cannot discriminate the stage of chronic liver disease in patients with severe chronic liver disease.

Impaired Platelet Aggregation and Rebalanced Hemostasis in Patients with Chronic Hepatitis C Virus Infection

Increased risk of both cardiovascular disease (CVD) and bleeding has been found in patients with chronic hepatitis C (CHC) infection, and a re-balanced hemostasis has been proposed. The aim of this study was to investigate functional whole blood coagulation and platelet function in CHC infection. The prospective study included 82 patients with CHC infection (39 with advanced liver fibrosis and 43 with no or mild liver fibrosis) and 39 healthy controls. A total of 33 patients were treated for CHC infection and achieved sustained virological response (SVR). Baseline and post-treatment blood samples were collected. Hemostasis was assessed by both standard coagulation tests and functional whole blood hemostatic assays (thromboelastograhy (TEG), and platelet aggregation (Multiplate). Patients with CHC and advanced fibrosis had impaired platelet aggregation both compared to patients with no or mild fibrosis and to healthy controls. Patients with CHC and advanced fibrosis also had lower antithrombin, platelet count, and coagulation factors II-VII-X compared to healthy controls. In contrast, TEG did not differ between groups. In treated patients achieving SVR, post-treatment platelet count was higher than pre-treatment counts (p = 0.033) and ADPtest, ASPItest, and RISTOhightest all increased post treatment (all p < 0.05). All Multiplate tests values, however, remained below those in the healthy controls. CHC-infected patients displayed evidence of rebalanced hemostasis with only partly hemostatic normalization in patients achieving SVR. The implications of rebalanced hemostasis and especially the impact on risk of CVD and bleeding warrants further studies.

Decreased prothrombin conversion and reduced thrombin inactivation explain rebalanced thrombin generation in liver cirrhosis

Impaired coagulation factor synthesis in cirrhosis causes a reduction of most pro- and anticoagulant factors. Cirrhosis patients show no clear bleeding or thrombotic phenotype, although they are at risk for both types of hemostatic event. Thrombin generation (TG) is a global coagulation test and its outcome depends on underlying pro- and anticoagulant processes (prothrombin conversion and thrombin inactivation). We quantified the prothrombin conversion and thrombin inactivation during TG in 30 healthy subjects and 52 Child-Pugh (CP-) A, 15 CP-B and 6 CP-C cirrhosis patients to test the hypothesis that coagulation is rebalanced in liver cirrhosis patients. Both prothrombin conversion and thrombin inactivation are reduced in cirrhosis patients. The effect on pro- and anticoagulant processes partially cancel each other out and as a result TG is comparable at 5 pM tissue factor between healthy subjects and patients. This supports the hypothesis of rebalanced hemostasis, as TG in cirrhosis patients remains within the normal range, despite large changes in prothrombin conversion and thrombin inactivation. Nevertheless, in silico analysis shows that normalization of either prothrombin conversion or thrombin inactivation to physiological levels, by for example the administration of prothrombin complex concentrates would cause an elevation of TG, whereas the normalization of both simultaneously maintains a balanced TG. Therefore, cirrhosis patients might require adapted hemostatic treatment.

Coagulopathy Before and After Liver Transplantation: From the Hepatic to the Systemic Circulatory Systems

The hemostatic environment in patients with cirrhosis is a delicate balance between prohemostatic and antihemostatic factors. There is a lack of effective laboratory measures of the hemostatic system in patients with cirrhosis. Many are predisposed to pulmonary embolus, deep vein thrombosis, and portal vein thrombosis in the pretransplantation setting. This pretransplantation hypercoagulable milieu seems to extend for at least several months post-transplantation. Patients with nonalcoholic fatty liver disease, inherited thrombophilia, portal hypertension in the absence of cirrhosis, and hepatocellular carcinoma often require individualized approach to anticoagulation. Early reports suggest a potential role for low-molecular-weight heparins and direct-acting anticoagulants.

Thromboelastographic Evaluation of Coagulation in Patients With Liver Disease

BACKGROUND

The aims of this study were to investigate the parameters of thromboelastography (TEG) for evaluating coagulopathy and to reveal an association with disease severity and/or transfusion requirement in patients with chronic liver disease (CLD) in a clinical laboratory setting.

METHODS

We enrolled two groups of adult patients with cirrhotic (N=123) and non-cirrhotic liver disease (N=52), as well as 84 healthy controls. Reaction time (R), kinetic time (K), α-angle (α), maximal amplitude (MA), and coagulation index (CI) were measured with kaolin-activated citrated blood with the TEG 5000 system (Haemonetics Corporation, USA). Platelet count, prothrombin time international normalized ratio (PT INR), albumin, bilirubin, and creatinine were simultaneously measured. The CLD severity was calculated by using the Child-Pugh (C-P) and Model for End-stage Liver Disease (MELD) scores. Transfusion history was also reviewed.

RESULTS

All TEG parameters, PT INR, and platelet count in the cirrhotic group showed significant differences from those in other groups. At least one or more abnormal TEG parameters were identified in 17.3% and 44.7% of patients in the non-cirrhotic and cirrhotic group, respectively. Patients with cirrhotic disease had hypocoagulability. A weak correlation between R and PT INR (r=0.173) was noted. The TEG parameters could not predict CLD severity using the C-P and MELD scores. Patients with normal TEG parameters did not receive transfusion.

CONCLUSIONS

Clinical application of TEG measurements in CLD can be informative for investigating coagulopathy or predicting the risk of bleeding. Further studies are warranted.

Hemostatic issues in pregnancy-induced liver disease

Liver diseases may be accompanied by profound changes in the hemostatic system including thrombocytopenia, decreased plasma levels of pro- and anticoagulants, and alterations in plasma levels of fibrinolysis. The net effect of the hemostatic changes in chronic and acute liver diseases is a hemostatic system that is in relative balance due to the simultaneous decline in pro- and antihemostatic drivers. A unique category of liver diseases are those induced by pregnancy. In acute fatty liver of pregnancy, profound hemostatic changes occur, which may be caused by a combination of liver failure and disseminated intravascular coagulation. Hemostatic changes in preeclampsia and HELLP syndrome are dominated by thrombocytopenia, although alterations in plasmatic coagulation may also occur. Post-partum bleeds, bleeding from cesarean section wounds, and hepatobiliary bleeds may occur in both patient groups. Patients with intrahepatic cholestasis of pregnancy do not show clinically relevant hemostatic alterations, despite biochemical evidence of liver injury.

Portal vein thrombosis in patients with cirrhosis

Portal vein thrombosis (PVT) is frequent in patients with liver cirrhosis and possible severe complications such as mesenteric ischemia are rare, but can be life-threatening. However, different aspects of clinical relevance, diagnosis and management of PVT are still areas of uncertainty and investigation in international guidelines. In this article, we elaborate on PVT classification, geographical differences in clinical presentation and standards of diagnosis, and briefly on the current pathophysiological understanding and risk factors. This review considers and highlights the pitfalls of the various treatment approaches and prophylactic treatments. Finally, we review the controversial issue of clinical impact of PVT on prognosis, especially considering liver transplantation and future perspectives.

Intraoperative Management of High-Risk Liver Transplant Recipients: Concerns and Challenges

Liver transplantation (LT) offers patients with liver disease a real chance for long-term survival. In the past decade, successful survival after LT along with the Model for End-Stage Liver Disease-based allocation policy have increased willingness to accept patients with a higher risk profile and marginal organs and to prioritize the sickest patients on the waiting list. Therefore, the anesthesiologist now deals with very challenging patients. In the present review, we aimed to highlight key aspects of intraoperative LT management in high-risk patients and to place these aspects in the perspective of their impact on perioperative outcomes. Conservative standardized perioperative strategies mandate a switch toward accurate and tailored perioperative anesthetic care to maintain the steady improvement in recipient survival rates after LT. In our opinion, continuous assessment of fluid status and cardiac performance, strategies promoting graft decongestion, rational hemostatic management, and the identification of LT recipients with potential risk of vascular complications should constitute the cornerstone of intraoperative management.

Increased soluble GPVI levels in cirrhosis: evidence for early in vivo platelet activation

Cirrhosis is a consequence of prolonged liver injury and is characterised by extensive tissue fibrosis: the deposition of collagen-rich extracellular matrix. The haemostatic balance is disordered in cirrhosis and coagulation activation appears to promote fibrosis. In spite of recent studies demonstrating a role for anticoagulant therapy in preventing cirrhosis progression, there has not been a change in clinical practice, suggesting that physicians are reluctant to anticoagulate patients with cirrhosis due to bleeding risks. Platelets play an important role in facilitating coagulation. Glycoprotein VI (GPVI) is a platelet-specific collagen receptor that is shed from the platelet surface in a metalloproteinase-dependent manner in response to GPVI ligation and coagulation activation. Our aim was to use soluble GPVI levels to determine whether there was evidence for collagen and coagulation-induced platelet activation in early, well-compensated cirrhosis. Plasma soluble GPVI levels were quantified in 46 patients with mixed aetiology cirrhosis and 55 healthy controls using an immunoassay. In the cirrhosis group, soluble GPVI levels were significantly increased (5.8 ± 4.4 ng/ml, n = 46) compared to healthy controls (3.3 ± 3.4 ng/ml, n = 55, p < 0.05). This increase in soluble GPVI levels was still evident when levels were adjusted for platelet count (Healthy controls; 0.015 ± 0.018 ng/10⁶ platelets/ml vs. cirrhosis; 0.048 ± 0.04 ng/10⁶ platelets/ml, p < 0.0001). This study provides evidence for early platelet activation in patients with well-compensated cirrhosis. This may have translational implications for prognosis, treatment, and risk stratification.