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]

Efficacy and safety of pharmacological venous thromboembolism prophylaxis following liver resection: a systematic review and meta-analysis

BACKGROUND

Current guidelines recommend pharmacological prophylaxis for patients undergoing abdominal surgery for malignancy. Liver resection exposes patients to risk factors for venous thromboembolism, but there is a risk of bleeding. The aim of this study is to evaluate the evidence base supporting the use of pharmacological thromboprophylaxis in liver surgery.

METHODS

An electronic search was carried out for studies reporting the incidence of VTE following liver resection comparing patients receiving pharmacological prophylaxis with those who did not. The search resulted in 990 unique citations. Following the application of strict eligibility criteria 5 studies comprise the final study population.

RESULTS

Included studies report on 3675 patients undergoing liver resection between 1999 and 2013. 2256 patients received chemical thromboprophylaxis, 1412 had mechanical prophylaxis only and 7 received no prophylaxis. Meta-analysis revealed lower VTE rates in patients receiving chemical thromboprophylaxis (2.6%) compared to without prophylaxis (4.6%) (Dichotomous correlation test, odds ratio: 0.631 [95% Cl: 0.416-0.959], Fixed model, p = 0.030). Data regarding bleeding could not be pooled for meta-analysis, but chemical thromboprophylaxis was reported as safe in four studies.

CONCLUSION

This systematic review and meta-analysis of retrospective studies indicates that the use of perioperative chemical thromboprophylaxis reduces VTE incidence following liver surgery without an apparent increased risk of bleeding.

Prediction of Intraoperative Blood Loss during Total Knee Arthroplasty in HCV+ and HCV- Patients with Hemophilia A

We examined HCV+ and HCV- hemophilia A patients with knee arthropathy and hematocrit above 38.5%. The mean density of erythrocytes was studied by the phthalate method, intraoperative blood loss was assessed gravimetrically. The volume of blood loss in HCV+ patients with manifest adhesive process and chronic synovitis varied from 300 to 1900 ml, in patients with moderate adhesive process from 400 to 1500 ml. The volume of blood loss in HCV- patients was 300-800 ml. A positive correlation between the blood loss volume and mean density of erythrocytes was detected. Blood loss >1000 ml during total knee arthroplasty can be expected in patients with hemophilia A with HCV and high mean density of erythrocytes. Blood loss >1000 ml is unlikely in HCV- and HCV+ patients with the mean density of erythrocytes not surpassing the normal values.

Envenoming by Viridovipera stejnegeri snake: a patient with liver cirrhosis presenting disruption of hemostatic balance

Background

In most cases of envenoming by the green habu Viridovipera stejnegeri in Taiwan coagulopathy is not observed.

Case presentation

Herein, we describe the case of a patient with liver cirrhosis who developed venom-induced consumptive coagulopathy after V. stejnegeri bite. Laboratory investigation revealed the following: prothrombin time > 100 s (international normalized ratio > 10), activated partial thromboplastin time > 100 s, fibrinogen < 50 mg/dL, and fibrin degradation product > 80 μg/mL. The patient recovered after administration of bivalent hemorrhagic antivenom, vitamin K, fresh frozen plasma and cryoprecipitate.

Conclusion

The liver, directly involved in the acute phase reaction, is the main responsible for neutralization of animal toxins. Any patient with history of liver cirrhosis bitten by a venomous snake, even those whose venoms present low risk of coagulopathy, should be very carefully monitored for venom-induced consumptive coagulopathy (VICC), since the hemostatic balance may be disrupted.

Anticoagulation in cirrhosis: a new paradigm?

The liver plays a crucial role in coagulation cascade. Global hemostatic process is profoundly influenced by the presence of liver disease and its complications. Patients with cirrhosis have impaired synthesis of most of the factors involved in coagulation and fibrinolysis process due to a reduced liver function and altered platelet count secondary to portal hypertension. Altered routine tests and thrombocytopenia were considered in the past as associated with increased risk of bleeding. These concepts explain both the routine use of plasma and/or platelets transfusion in patients with liver cirrhosis, especially before invasive procedures, and why these patients were considered "auto-anticoagulated". New recent evidences show that patients with liver cirrhosis have a more complex hemostatic alteration. Despite the presence of altered levels of factors involved in primary hemostasis, coagulation and fibrinolysis, patients with stable cirrhosis have a rebalanced hemostatic, which however can easily be altered by decompensation or infection, both in hemorrhagic or thrombotic direction. Patients with cirrhosis have an increased risk of venous thrombotic events (namely portal vein thrombosis) while bleeding seems to be related to the grade of portal hypertension rather than to a hemostatic imbalance. The use of anticoagulants both as treatment or prophylaxis is safe, reduces the rate of portal vein thrombosis and decompensation, and improves survival. Standard laboratory coagulation tests are unable to predict bleeding and are inadequate for the assessment of hemostatic status in these patients, hence more comprehensive tests are required to guide the management of thrombotic and bleeding complications.

Thromboelastography in Dogs with Chronic Hepatopathies

BACKGROUND

The coagulation status of dogs with liver disease is difficult to predict using conventional coagulation testing.

HYPOTHESIS/OBJECTIVES

To evaluate thromboelastography (TEG) results and associations with conventional coagulation results and indicators of disease severity and prognosis in dogs with chronic hepatopathies (CH).

ANIMALS

Twenty-one client-owned dogs.

METHODS

Dogs with CH were prospectively (10 dogs) and retrospectively (11 dogs) enrolled from 2008 to 2014. Kaolin-activated TEG was performed and compared with reference intervals by t-tests or Mann-Whitney tests. Correlation coefficients for TEG results and conventional coagulation and clinicopathologic results were determined. Significance was set at P < .05.

RESULTS

Dogs with CH had significant increases in R (5.30 min vs 4.33 min), K (3.77 min vs 2.11 min), and LY30 (4.77% vs 0.68%) and decreased angles (55.3° vs 62.4°). G value defined 9 of 21, 7 of 21, and 5 of 21 dogs as normocoagulable, hypercoagulable, and hypocoagulable, respectively. G and MA were correlated with fibrinogen (r = 0.68, 0.83), prothrombin time (PT; r = -0.51, -0.53), and activated partial thromboplastin time (aPTT; r = -0.50, -0.50). K was correlated with PT (r = 0.75) and protein C activity (r = -0.92). Angle was correlated with aPTT (r = -0.63). Clinical score was correlated with PT (r = 0.60), MA (r = -0.53), and R (r = -0.47). Dogs with hyperfibrinolysis (LY30 > 3.04%; 5 of 21) had significantly higher serum transaminase activities. Dogs with portal hypertension had significantly lower G, MA, and angle and prolonged, K, R, and PT.

CONCLUSIONS AND CLINICAL RELEVANCE

Dogs with CH have variable TEG results. Negative prognostic indicators in CH correlate with hypocoagulable parameters on TEG. Hyperfibrinolysis in dogs with CH is associated with high disease activity.

Value of Preoperative Hemostasis Testing in Patients with Liver Disease for Perioperative Hemostatic Management

Preoperative hemostasis testing may have limited use in patients with liver disease, and an abnormal platelet count, prothrombin time, activated partial thromboplastin time, and fibrinogen level should not trigger prophylactic transfusion of blood product components.

Emerging strategies for the treatment of patients with acute hepatic failure

PURPOSE OF REVIEW

The objective of this article is to review the latest developments related to the treatment of patients with acute liver failure (ALF).

RECENT FINDINGS

As the treatment of ALF has evolved, there is an increasing recognition regarding the risk of intracranial hypertension related to advanced hepatic encephalopathy. Therefore, there is an enhanced emphasis on neuromonitoring and therapies targeting intracranial hypertension. Also, new evidence implicates systemic proinflammatory cytokines as an etiology for the development of multiorgan system dysfunction in ALF; the recent finding of a survival benefit in ALF with high-volume plasmapheresis further supports this theory.

SUMMARY

Advances in the critical care management of ALF have translated to a substantial decrease in mortality related to this disease process. The extrapolation of therapies from general neurocritical care to the treatment of ALF-induced intracranial hypertension has resulted in improved neurologic outcomes. In addition, recognition of the systemic inflammatory response and multiorgan dysfunction in ALF has guided current treatment recommendations, and will provide avenues for future research endeavors. With respect to extracorporeal liver support systems, further randomized studies are required to assess their efficacy in ALF, with attention to nonsurvival end points such as bridging to liver transplantation.

Plasma Transfusion in Patients With Cirrhosis in China: A Retrospective Multicenter Cohort Study

Patients with cirrhosis used to be associated with frequent use of blood components because of their complex disorder of hemostasis and bleeding complications. Recent findings have indicated that patients with cirrhosis have a state of "rebalanced" or even procoagulant hemostasis and have questioned the prophylactic use of plasma. To evaluate the current status of plasma use in patients with cirrhosis, we conducted a retrospective survey in 11 tertiary-care hospitals in China from September 1 to October 31, 2013. All patients admitted with cirrhosis during the study period were included in the study. The survey collected information including patients' diagnostic and demographic data, clinical course including bleeding complications and invasive procedures, laboratory results, and plasma transfusion data. Among 1595 patients with cirrhosis admitted to the 11 hospitals, 236 (14.8%) patients received 1 or more plasma transfusions during the study period. The number of plasma transfusions is defined as the number of transfusion orders. A total of 1037 plasma transfusions were administered to these patients, with a mean of 4.4 transfusions per transfused patient, ranging from 1 to 22 transfusions per transfused patient. Most plasma transfusions (760/1037; 73.3%) were given to patients without bleeding, for treatment of coagulopathy either without planned invasive procedures (70.4%) or before invasive procedures (2.9%). The median dose of plasma transfusion was 3.8 mL/kg. The rate of plasma transfusion of participating hospitals varied from 5.3% to 31.8%. It is encouraging to see that in one teaching hospital, 85.7% plasma transfusions were given to patients with bleeding indication, showing a promising sign in appropriate transfusion. Prophylaxis or empirical plasma transfusion is still a common problem in managing patients with liver cirrhosis. Wide variations are found in plasma transfusion practice among hospitals. Effective measures to control and reduce empirical correction of abnormal coagulation tests through transfusing plasma should be strengthened urgently.

A multicenter study of blood component transfusion in patients with liver cirrhosis in China: Patient characteristics, transfusion practice, and outcomes

BACKGROUND

Cirrhosis is a complex acquired disorder of hemostasis and patients frequently receive blood transfusions. But there is very limited data on patterns of blood use at a patient level.

AIMS

To characterize blood use in cirrhotic patients in China and compare with recommendations to help identify areas where quality improvement strategies can be targeted. We also compared findings to a similar study undertaken in UK.

METHODS

A cross-sectional study was conducted in 11 hospitals over a 2-month period. Data were collected prospectively on each hospitalized cirrhotic patient to day 28.

RESULTS

1595 cirrhotic patients were included and 20.6% were transfused. 48.2% of transfused patients received transfusion for bleeding, most commonly gastrointestinal bleeding (65.8%). The remaining 51.8% were transfused for non-bleeding indications. 32.5% of patients transfused for gastrointestinal bleeding with red blood cells had a pre-transfusion haemoglobin >7g/dL. 89.1% of patients transfused frozen plasma for non-bleeding indications received them in the absence of a planned procedure. The patterns of blood transfusion in cirrhosis were different between China and UK. Of note, empirical prophylactic use of frozen plasma was more common in the Chinese study (89%) than in the UK (24%).

CONCLUSION

Education and research should be implemented to improve patient blood management, especially in prophylactic frozen plasma use area.

Venous Thrombotic Events After Liver Transplantation

Thromboprophylaxis is not well defined after liver transplantation (LT). The aim of this study was to evaluate the incidence of splanchnic vein thrombosis (SVT) and nonsplanchnic vein thrombosis (NSVT) after LT. Liver transplantations performed between 2009 and 2013 in our institution were reviewed. Demographic, intraoperative, and postoperative data were recorded. Low-molecular-weight heparin was only administered postoperatively if intraoperative thrombectomy was performed or in patients preoperatively anticoagulated. Of a total of 328 patients, 72% were male with a median age of 56 years, score of model for end-stage liver disease 18 (11-23), and 88% had liver cirrhosis. The incidence of postoperative venous thrombotic events was 4.6%: 8 (2.4%) patients had SVT and 7 (2.1%) patients had NSVT. After logistic regression analysis, intraoperative thrombectomy and Child A classification emerged as risk factors for SVT (odds ratio [OR]: 77, 95% confidence interval [95% CI]: 14-421) and NSVT (OR: 20, 95% CI: 3-170), respectively. The incidence of SVT in patients who undergo intraoperative thrombectomy was 33%, whereas the incidence of NSVT in patients grouped as Child A was 7.5%. Our results suggest that thromboprophylaxis should be considered after LT in patients with cirrhosis grouped as Child A and in patients who undergo intraoperative thrombectomy.

Liver transplantation in Jehovah's Witnesses: two cases report

Liver transplantation is especially challenging in patients who are Jehovah's Witnesses because their religious beliefs prohibit the receipt of blood products. We present two cases of living donor liver transplantation performed in adult Jehovah's Witnesses in South Korea without the use of blood products. In the first case, preoperative erythropoiesisstimulation therapy increased hemoglobin levels from 8.1 to 13.1 g/dl after 9 weeks. In the second case, hemoglobin levels increased from 7.4 to 10.8 g/dl after 6 months of erythropoiesis-stimulation therapy. With the combination of acute normovolemic hemodilution, intraoperative cell salvage, and use of transfusion alternatives, liver transplantation was successfully performed without transfusion of blood products.

The Utility of Viscoelastic Testing in Patients Undergoing IR Procedures

Whole-blood viscoelastic testing can identify patient-specific coagulation disturbances, allowing for targeted repletion of necessary coagulation factors and differentiation between coagulopathy and surgical bleeding that requires intervention. Viscoelastic testing complements standard coagulation tests and has been shown to decrease transfusion requirements and improve survival in bleeding patients. Viscoelastic testing also can be used to predict bleeding and improve the care of patients undergoing interventional radiology (IR) procedures.

von Willebrand factor and procoagulant imbalance predict outcome in patients with cirrhosis and thrombocytopenia

BACKGROUND & AIMS

Several lines of evidence suggest that the hemostatic disorders of cirrhosis may have a significant clinical impact. We investigated the independent predictive value of components of the hemostatic system on the occurrence of ascites, variceal bleeding (VB), and survival.

METHODS

One hundred and two patients with thrombocytopenia (Child-Pugh class A/B/C: 34/34/34) were enrolled. Platelet counts, factors (F) II, V, VII, and VIII, antithrombin, protein C (PC), FVIII-to-PC ratio as an index of procoagulant imbalance, von Willebrand factor antigen (vWF-Ag), and model for end-stage liver disease (MELD) were evaluated. Two multivariate analyses were performed: one excluding (model 1) and one including MELD (model 2).

RESULTS

Higher vWF-Ag levels and FVIII-to-PC ratios were the most prominent hemostatic disorders in patients with cirrhosis. Increased levels of vWF-Ag and FVIII, and higher FVIII-to-PC ratios independently predicted the presence of ascites and varices at baseline. Independent predictors of ascites and VB during follow-up were vWF-Ag (model 1/2: p=0.001/p=0.009 and p=0.008/p=0.01, respectively) and FVIII-to-PC ratio (model 1/2: p=0.003/p=0.02 and p=0.01/p=0.03, respectively). vWF-Ag (model 1/2: p=0.007/p=0.002), FVIII-to-PC ratio (model 1/2: p=0.001/p=0.01), and MELD (p=0.02) independently predicted mortality. Patient groups with significantly higher probability of new-onset ascites, VB, and mortality were identified by certain cut-offs of vWF-Ag (213%, 466%, and 321%, respectively) and FVIII-to-PC ratio (1.99, 3.29, and 2.36, respectively). vWF-Ag and FVIII-to-PC ratio equaled MELD in mortality prediction.

CONCLUSIONS

Advanced cirrhosis is characterized by increased thrombotic potential. vWF-Ag and FVIII-to-PC ratio independently predict new-onset ascites, VB, and mortality. Targeting hypercoagulability could improve the outcome of patients with cirrhosis.

LAY SUMMARY

Higher von Willebrand factor antigen (vWF-Ag) levels and factor VIII-to-protein C (FVIII-to-PC) ratio are the prominent hemostatic disorders in patients with cirrhosis. vWF-Ag and FVIII-to-PC ratio independently predict new-onset ascites, variceal bleeding, and mortality in these patients.

Association of conventional haemostasis and coagulation tests with the risk of acute upper gastrointestinal bleeding in liver cirrhosis: a retrospective study

OBJECTIVE

A retrospective study was performed to compare the difference in platelet count (PLT), prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (APTT), between cirrhotic patients with and without acute upper gastrointestinal bleeding (AUGIB) or acute oesophageal variceal bleeding (AEVB).

METHODS

Between January 2012 and June 2014, a total of 1734 cirrhotic patients were enrolled and were classified into 'AUGIB' (n = 497) and 'no AUGIB' (n = 1237) groups according to their disease history. They were further divided into 'AEVB' (n = 297) and 'no AEVB' (n = 1259) groups according to the endoscopic findings. Additionally, 178 patients with AUGIB were not assigned to either the 'AEVB' or 'no AEVB' groups due to the absence of any endoscopic findings.

RESULTS

Compared with the 'no AUGIB' group, the 'AUGIB' group had similar PLT (99.99 ± 89.90 vs.101.47 ± 83.03; P = 0.734) and APTT (42.96 ± 15.20 vs.43.77 ± 11.01; P = 0.219), but significantly higher PT (17.30 ± 5.62 vs.16.03 ± 4.68; P < 0.001) and INR (1.45 ± 0.69 vs.1.31 ± 0.59; P < 0.001). A lower PT was independently associated with the absence of AUGIB (OR = 0.968; 95% CI: 0.942-0.994). Compared with the 'no AEVB' group, the 'AEVB' group had significantly lower PLT (86.87 ± 62.14 vs.101.74 ± 83.62; P = 0.004) and APTT (40.98 ± 7.9 vs.43.72 ± 10.97; P < 0.001), but similar PT (16.53 ± 3.71 vs.16.04 ± 4.68; P = 0.088) and INR (1.35 ± 0.41 vs.1.31 ± 0.59; P = 0.225). A higher PLT was independently associated with the absence of AEVB (OR = 1.004; 95% CI: 1.002-1.006; P = 0.001).

CONCLUSIONS

PLT was associated with the occurrence of portal hypertension-related bleeding in liver cirrhosis.

The risk of venous thromboembolism in patients with cirrhosis. A systematic review and meta-analysis

Some studies suggest that patients with cirrhosis have an increased risk of deep venous thrombosis (DVT) and pulmonary embolism (PE). Unfortunately, available data on this association are contrasting. It was the objective of this study to perform a systematic review and meta-analysis of literature to evaluate the risk of venous thromboembolism (VTE) associated with cirrhosis. Studies reporting on VTE risk associated with cirrhosis were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. Eleven studies (15 data-sets) showed a significantly increased VTE risk in 695,012 cirrhotic patients as compared with 1,494,660 non-cirrhotic controls (OR: 1.703; 95 %CI: 1.333, 2.175; P<0.0001). These results were confirmed when specifically considering the risk of DVT (7 studies, OR: 2.038; 95 %CI: 1.817, 2.285; P<0.0001) and the risk of PE (5 studies, OR: 1.655; 95 %CI: 1.042, 2.630; p=0.033). The increased VTE risk associated with cirrhosis was consistently confirmed when analysing nine studies reporting adjusted risk estimates (OR: 1.493; 95 %CI: 1.266, 1.762; p<0.0001), and after excluding studies specifically enrolling populations exposed to transient risk factors for VTE (OR: 1.689; 95 %CI: 1.321, 2.160; p<0.0001). Meta-regression models suggested that male gender may significantly impact on the risk of VTE associated with cirrhosis. Results of our meta-analysis suggest that cirrhotic subjects may exhibit an increased risk of VTE. This should be considered to plan specific prevention strategies in this clinical setting.

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.

Identification of Organ-Enriched Protein Biomarkers of Acute Liver Injury by Targeted Quantitative Proteomics of Blood in Acetaminophen- and Carbon-Tetrachloride-Treated Mouse Models and Acetaminophen Overdose Patients

Organ-enriched blood proteins, those produced primarily in one organ and secreted or exported to the blood, potentially afford a powerful and specific approach to assessing diseases in their cognate organs. We demonstrate that quantification of organ-enriched proteins in the blood offers a new strategy to find biomarkers for diagnosis and assessment of drug-induced liver injury (and presumably the assessment of other liver diseases). We used selected reaction monitoring (SRM) mass spectrometry to quantify 81 liver-enriched proteins plus three aminotransferases (ALT1, AST1, and AST2) in plasma of C57BL/6J and NOD/ShiLtJ mice exposed to acetaminophen or carbon tetrachloride. Plasma concentrations of 49 liver-enriched proteins were perturbed significantly in response to liver injury induced by one or both toxins. We validated four of these toxin-responsive proteins (ALDOB, ASS1, BHMT, and GLUD1) by Western blotting. By both assays, these four proteins constitute liver injury markers superior to currently employed markers such as ALT and AST. A similar approach was also successful in human serum where we had analyzed 66 liver-enriched proteins in acetaminophen overdose patients. Of these, 23 proteins were elevated in patients; 15 of 23 overlapped with the concentration-increased proteins in the mouse study. A combination of 5 human proteins, AGXT, ALDOB, CRP, FBP1, and MMP9, provides the best diagnostic performance to distinguish acetaminophen overdose patients from controls (sensitivity: 0.85, specificity: 0.84, accuracy: 85%). These five blood proteins are candidates for detecting acetaminophen-induced liver injury using next-generation diagnostic devices (e.g, microfluidic ELISA assays).

Four-Factor Prothrombin Complex Concentrate for Coagulopathy Reversal in Patients With Liver Disease

A 4-factor prothrombin complex concentrate (4F-PCC, Kcentra®) was recently approved in the United States for the reversal of vitamin K antagonist-associated major bleeding, but it is often used to reverse coagulopathy in patients with liver disease (LD). This single-center, retrospective study analyzed the efficacy and safety of 4F-PCC administered in patients with and without LD. Prothrombin time/International Normalized Ratio (PT/INR) reversal with 4F-PCC was attempted in 85 patients; LD was documented in 31 patients. Coagulopathy reversal and hemostasis with 4F-PCC were inferior in patients with LD compared to patients without LD. Coagulopathy reversal, defined as INR = 1.5 after 4F-PCC administration, was achieved in 6 (19.4%) LD patients, compared to 44 (81.5%) non-LD patients ( p < 0.01). Hemostasis was achieved in 6 LD patients (19.4%) compared to 23 non-LD patients (42.6%) ( p = 0.03). Thromboembolic events occurred in 1 LD patient (3.2%) and 8 non-LD patients (14.8%) ( p = 0.15). Mortality was 51.6% in LD patients and 18.5% in non-LD patients ( p < 0.01). These observations suggest that the efficacy of 4F-PCC is suboptimal to correct coagulopathy and hemostasis in patients with LD, who have high rates of in-hospital mortality due to sequelae of LD. The incidence of thromboembolic events appeared comparable, suggesting that 4F-PCC does not cause undue thromboembolism in LD patients. In conclusion, 4F-PCC appears to be safe in LD patients when administered judiciously; however, further studies are necessary to optimize its use and elucidate its hemostatic potential in this patient population.

The risk of coronary artery disease and cerebrovascular disease in patients with hepatitis C: A systematic review and meta-analysis

BACKGROUND/OBJECTIVES

Some studies suggest that patients with hepatitis C virus (HCV) infection have an increased risk of coronary artery disease (CAD) and cerebrovascular disease. Unfortunately, available data on this association are widely variable. We have performed a systematic review and meta-analysis of literature to evaluate the risk of cardio-cerebrovascular disease (CCD) associated with HCV.

METHODS

Studies reporting on CCD risk associated with HCV were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases.

RESULTS

Twenty-seven studies (34 data-sets) showed a significantly increased CCD risk in 297,613 HCV patients as compared with 557,814 uninfected controls (OR: 1.428; 95% CI: 1.214, 1.681). These results were confirmed when separately considering the risk of CAD (20 studies, OR: 1.382; 95% CI: 1.103, 1.732) and of cerebrovascular disease (13 studies, OR: 1.485; 95% CI: 1.079, 2.044). Similar results were confirmed when analyzing 21 studies reporting adjusted risk estimates (OR: 1.448; 95% CI: 1.218, 1.722) and when, after excluding studies defining CAD as positive angiographic or electrocardiographic evidence, we specifically included the 17 studies reporting on acute CCD-related events (OR: 1.357; 95% CI: 1.103, 1.670). Moreover, 4 studies evaluating CCD-related deaths showed a higher risk in HCV patients than controls (OR: 1.772; 95% CI: 1.448, 2.168; P<0.0001). Meta-regression models suggested a direct association between prevalence of cirrhosis and difference in CCD risk between HCV patients and controls.

CONCLUSIONS

Results of our large meta-analysis suggest that HCV-infected subjects experience an increased risk of CCD. This should be considered to plan specific cardiovascular prevention strategies in this clinical setting.

Procoagulant changes in fibrin clot structure in patients with cirrhosis are associated with oxidative modifications of fibrinogen

Essentials Patients with cirrhosis have hemostatic changes, which may contribute to a risk of thrombosis. This in vitro study compares clot formation and structure between patients and healthy subjects. Clot formation is delayed in patients; ultimately, however, clot permeability is decreased. The thrombogenic structure of fibrin clots may contribute to the thrombotic risk in cirrhosis.

ABSTRACT

Background and Objectives Patients with cirrhosis can be at risk of thrombotic complications due to an imbalance between hemostatic components. However, little is known on how the disease affects clot generation or how alterations in the structure of fibrin clots may affect the hemostatic function of these patients. Methods We investigated the formation and structure of clots generated with plasma and purified fibrinogen of 42 patients with cirrhosis. Clots generated with plasma and fibrinogen of 29 healthy volunteers were studied for comparison. Clot formation and structure were assessed by turbidity, permeation studies, confocal laser and scanning electron microscopy (SEM). The extent of fibrinogen oxidation was assessed by measuring the carbonyl content of purified fibrinogen samples. Results Tissue factor and thrombin-induced clotting of plasma was delayed in patients. The clotting rate was also decreased, but change in turbidity, fibrin density and fiber thickness were largely comparable to healthy volunteers. Conversely, clot permeability was significantly decreased in patients. When clots were generated with purified fibrinogen, differences in clot formation and structure similar to those in plasma were found. The carbonyl content was increased in patient fibrinogen and correlated with disease severity and clot permeability. Conclusions Delayed clot formation in cirrhosis ultimately results in decreased clot permeability. Similar alterations in clots generated with purified fibrinogen suggest that modifications of the molecule are (partly) responsible. Taken together, these findings are indicative of hypercoagulable features of clots of patients with cirrhosis, which may explain the increased risk of thrombosis associated with this condition.

What Is the Biological and Clinical Relevance of Fibrin?

As our knowledge of the structure and functions of fibrinogen and fibrin has increased tremendously, several key findings have given some people a superficial impression that the biological and clinical significance of these clotting proteins may be less than earlier thought. Most strikingly, studies of fibrinogen knockout mice demonstrated that many of these mice survive to weaning and beyond, suggesting that fibrin(ogen) may not be entirely necessary. Humans with afibrinogenemia also survive. Furthermore, in recent years, the major emphasis in the treatment of arterial thrombosis has been on inhibition of platelets, rather than fibrin. In contrast to the initially apparent conclusions from these results, it has become increasingly clear that fibrin is essential for hemostasis; is a key factor in thrombosis; and plays an important biological role in infection, inflammation, immunology, and wound healing. In addition, fibrinogen replacement therapy has become a preferred, major treatment for severe bleeding in trauma and surgery. Finally, fibrin is a unique biomaterial and is used as a sealant or glue, a matrix for cells, a scaffold for tissue engineering, and a carrier and/or a vector for targeted drug delivery.

Image-guided intervention in the coagulopathic patient

Determining practice parameters for interventional procedures is challenging due to many factors including unreliable laboratory tests to measure bleeding risk, variable usage of standardized terminology for adverse events, poorly defined standards for administration of blood products, and the growing numbers of anticoagulant and antiplatelet medications. We aim to address these and other issues faced by radiologists performing invasive procedures through a review of available literature, and experiential guidance from three academic medical centers. We discuss the significant limitations with respect to using prothrombin-time and international normalized ratio to measure bleeding risk, especially in patients with synthetic defects due to liver function. Factors affecting platelet function including the impact of uremia; recent advances in laboratory testing, including platelet function testing; and thromboelastography are also discussed. A review of the existing literature of fresh-frozen plasma replacement therapy is included. The literature regarding comorbidities affecting coagulation including malignancy, liver failure, and uremia are also reviewed. Finally, the authors present a set of recommendations for laboratory thresholds, corrective transfusions, as well as withholding and restarting medications.

Ex vivo evaluation of 4 different viscoelastic assays for detecting moderate to severe coagulopathy during liver transplantation

Prolonged prothrombin time (PT) and its ratio are routinely used for the assessment of candidates for liver transplantation (LT), but intraoperative coagulation management of transfusion is hindered by its long turnaround time. Abnormal reaction time (R time) on thromboelastography (TEG) or clotting time (CT) of rotational thromboelastometry (ROTEM) are presumably an alternative, but there is a paucity of clinical data on abnormal R time/CT values compared to PT during LT. After receiving institutional review board approval and informed consent, we obtained blood samples from 36 LT patients for international normalized ratio (INR), factor (F) X level, and viscoelastic tests (EXTEM/INTEM and kaolin/rapid TEG) at baseline and 30 minutes after graft reperfusion. Receiver operating characteristic (ROC) curves were calculated for INR > 1.5 and viscoelastic R time/CT thresholds to assess the ability to diagnose FX deficiency at the moderate (<50%) or severe (<35%) level. The FX deficiency data were calculated using cutoff values of INR (>1.5) and abnormal R time/CT for TEG and ROTEM. Tissue factor (TF)-activated INR and EXTEM-CT performed well in diagnosing FX below 50%, but rapid TEG with combined TF and kaolin activators failed. Improved performance of INTEM-CT in diagnosing FX below 35% underlies multifactorial deficiency involving both intrinsic and common pathways. In conclusion, the differences among different viscoelastic tests and clinical situations should be carefully considered when they are used to guide transfusion during LT.

Epidemiology, Risk Factors, and In-Hospital Mortality of Venous Thromboembolism in Liver Cirrhosis: A Single-Center Retrospective Observational Study

BACKGROUND

Risk of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), may be increased in liver cirrhosis. We conducted a single-center study to explore the epidemiology, risk factors, and in-hospital mortality of VTE in Chinese patients with liver cirrhosis.

MATERIAL/METHODS

All patients with liver cirrhosis who were consecutively admitted to our hospital between January 2011 and December 2013 were retrospectively included.

RESULTS

Of 2006 patients with liver cirrhosis included, 9 patients were diagnosed with or developed VTE during hospitalization, including 5 patients with a previous history of DVT, 1 patient with either a previous history of DVT or new onset of PE, and 3 patients with new onset of VTE (PE, n=1; DVT, n=2). Risk factors for VTE included a significantly higher proportion of hypertension and significantly higher red blood cells, hemoglobin, alanine aminotransferase, aspartate aminotransferase, prothrombin time (PT), international normalized ratio (INR), D-dimer, and Child-Pugh scores. The in-hospital mortality was significantly higher in patients with VTE than those without VTE (33.3% [3/9] versus 3.4% [67/1997], P<0.001).

CONCLUSIONS

VTE was observed in 0.4% of patients with liver cirrhosis during hospitalization and it significantly increased the in-hospital mortality. Elevated PT/INR aggravated the risk of VTE.

Primary prevention and treatment of venous thromboembolic events in patients with gastrointestinal cancers - Review

Venous thromboembolism event (VTE) is a common and morbid complication in cancer patients. Patients with gastrointestinal cancers often suffer from symptomatic or incidental splanchnic vein thrombosis, impaired liver function and/or thrombocytopenia. These characteristics require a thorough risk/benefit evaluation for individual patients. Considering the risk factors for the development of VTE and bleeding events in addition to recent study results may be helpful for correct initiation of primary pharmacological prevention and treatment of cancer-associated thrombosis (CAT), preferably with low molecular weight heparins (LMWH). Whereas thromboprophylaxis is most often recommended in hospitalized surgical and non-surgical patients with malignancy, there is less agreement as to its duration. With regard to ambulatory cancer patients, the lack of robust data results in low grade recommendations against routine use of anticoagulant drugs. Anticoagulation with LMWH for the first months is the evidence-based treatment for acute CAT, but duration of secondary prevention and the drug of choice are unclear. Based on published guidelines and literature, this review will focus on prevention and treatment strategies of VTE in patients with gastrointestinal cancers.

Current approaches to the management of patients with liver cirrhosis who have acute esophageal variceal bleeding

OBJECTIVE

Esophageal variceal bleeding is the most dangerous complication in patients with liver cirrhosis, and it is accompanied by high mortality. Their treatment can be complex, and requires a multidisciplinary approach. This review examines current approaches to the management of patients with liver cirrhosis who have acute esophageal variceal bleeding.

METHODS

PubMed, Google Scholar, and Cochrane Systematic Reviews were searched for articles published between 1987 and 2015. Relevant articles were identified using the following terms: 'esophageal variceal bleeding', 'portal hypertension' and 'complications of liver cirrhosis'. The reference lists of articles identified were also searched for other relevant publications. Inclusion criteria were restricted to the management of patients with liver cirrhosis who have acute esophageal variceal bleeding.

RESULTS

It is currently recommended to combine vasoactive drugs (preferable somatostatin or terlipressin) and endoscopic therapies (endoscopic band ligation as first choice, sclerotherapy if endoscopic band ligation not feasible) for the initial treatment of acute variceal bleeding. Antibiotic prophylaxis must be regarded as an integral part of the treatment. The use of a Sengstaken-Blakemore tube is appropriate only in cases of refractory bleeding if the above methods cannot be used. An alternative to balloon tamponade may be the installation of self-expandable metal stents. The transjugular intrahepatic portosystemic shunt is an extremely useful technique for the treatment of acute bleeding from esophageal varices. Although most current clinical guidelines classify it as second-line therapy, the Baveno VI workshop recommends early transjugular intrahepatic portosystemic shunt with expanded polytetrafluoroethylene-covered stents within 72 h (ideally <24 h) in patients with esophageal variceal bleeding at high risk of treatment failure (e.g. Child-Turcotte-Pugh class C < 14 points or Child-Turcotte-Pugh class B with active bleeding) after initial pharmacological and endoscopic therapy. Urgent surgical intervention is rarely performed and can be considered only in case of failure of conservative and/or endoscopic therapy and being unable to use a transjugular intrahepatic portosystemic shunt. Among surgical operations described in the literature are a variety of portocaval anastomosis and azygoportal disconnection procedures.

CONCLUSIONS

To improve the results of treatment for patients with liver cirrhosis who develop acute esophageal variceal bleeding, it is important to stratify patients into risk groups, which will allow one to tailor therapeutic approaches to the expected results.

Venous Thromboembolism Prophylaxis in Liver Surgery

BACKGROUND

At a recently concluded Americas Hepato-Pancreato-Biliary Association Annual Meeting, a Clinical Practice Guidelines Conference Series was convened with the topic focusing on Venous Thromboembolism (VTE) Prophylaxis in Liver Surgery. The symposium brought together hepatobiliary surgeons from three continents as well as medical experts in hematology and coagulation.

METHODS

The content of the discussion included literature reviews, evaluation of multi-institutional VTE outcome data, and examination of practice patterns at multiple high-volume centers.

RESULTS

Literature review demonstrated that, within gastrointestinal surgery, liver resection patients are at particularly high-risk for VTE. Recent evidence clearly indicates a direct relationship between the magnitude of hepatectomy and postoperative VTE rates, however, the PT/INR does not accurately reflect the coagulation status of the post-hepatectomy patient. Evaluation of available data and practice patterns regarding the utilization and timing of anticoagulant VTE prophylaxis led to recommendations regarding preoperative and postoperative thromboprophylaxis for liver surgery patients.

CONCLUSIONS

This conference was effective in consolidating our knowledge of coagulation abnormalities after liver resection. Based on the expert review of the available data and practice patterns, a number of recommendations were developed.

Ex vivo addition of fibrinogen concentrate improves the fibrin network structure in plasma samples taken during liver transplantation

BACKGROUND

Optimal hemostatic management during orthotopic liver transplantation (OLT) remains a challenge. The cause of bleeding during OLT is multifactorial, and may include hemostatic imbalance. Fibrinogen concentrates are increasingly being used to control perioperative bleeding during OLT. However, administration is based on arbitrary thresholds of fibrinogen levels. Importantly, studies on fibrin clot structure during OLT are lacking.

OBJECTIVE

We determined the hemostatic efficacy of fibrinogen concentrate in correcting the fibrin structure.

METHODS

Plasma samples taken at various times during OLT from 15 patients and 15 healthy controls were spiked with 1 g L(-1) fibrinogen concentrate or saline. Turbidity, fibrin fiber density and permeability of the fibrin clots were assessed.

RESULTS

Clotting rate and turbidity were significantly decreased at the start of surgery, and decreased even further during surgery. Addition of fibrinogen significantly increased the clotting rate and turbidity at all time points, but did not normalize it. Fibrin density was significantly reduced after reperfusion as compared with the density at the start of surgery and in healthy controls. Fibrin density improved significantly after addition of fibrinogen in samples taken at the start of surgery and after reperfusion. The severely impaired polymerization and decreased density after reperfusion were accompanied by significantly increased permeability of the clot as compared with the start of surgery and in controls, which was completely restored after addition of fibrinogen.

CONCLUSIONS

Ex vivo addition of fibrinogen concentrate during OLT substantially improves the structural properties of the fibrin clot, which, particularly after reperfusion, shows hypocoagulable features. These data support the use of fibrinogen concentrate to control bleeding complications during OLT.

Usefulness of thromboelastometry in predicting the risk of bleeding in cirrhotics who undergo invasive procedures

OBJECTIVES

The management of patients with liver cirrhosis undergoing invasive procedures is controversial and haemostasis assessment using routine laboratory is inappropriate. We evaluated the following: (a) the ability of thromboelastometry to predict the risk of bleeding in cirrhotic patients undergoing invasive procedures and enable a decision on the prophylactic transfusional strategy; (b) the contribution of platelet adhesion and aggregation tests in the assessment of haemostasis.

PATIENTS AND METHODS

Seventeen cirrhotic patients undergoing invasive procedures were analyzed retrospectively (training set). To obtain preliminary data, an observational study was carried out in 58 patients (test set). All 75 patients were evaluated by thromboelastometry. Platelet adhesion and aggregation were evaluated in 16 patients using Multiplate, PFA-100 and Light Transmission Aggregometry. Factor VIII was dosed in all patients of the test set.

RESULTS

In the training set, thromboelastometry confirmed the haemostatic assessment shown by the conventional test only in 6/17 (35%) patients. In the test set, thromboelastometry identified all patients who had a bleeding event. In patients with a high risk of bleeding, the use of thromboelastometry was cost-effective, reducing the platelet infusions by 64%. Platelet adhesion/aggregation abnormalities were observed in 15/16 (94%) patients, but bleeding events occurred only in 2/15 (13%) patients.

CONCLUSION

Thromboelastometry appears to be useful to screen cirrhotic patients undergoing invasive procedures to identify the risk of bleeding and to optimize the transfusional strategy. Adhesion/aggregation tests are not useful in identifying patients at risk of bleeding and their application is not cost-effective.

Transoesophageal echocardiography during liver transplantation

Liver transplantation (LT) has become the standard of care for patients with end stage liver disease. The allocation of organs, which prioritizes the sickest patients, has made the management of liver transplant candidates more complex both as regards their comorbidities and their higher risk of perioperative complications. Patients undergoing LT frequently display considerable physiological changes during the procedures as a result of both the disease process and the surgery. Transoesophageal echocardiography (TEE), which visualizes dynamic cardiac function and overall contractility, has become essential for perioperative LT management and can optimize the anaesthetic management of these highly complex patients. Moreover, TEE can provide useful information on volume status and the adequacy of therapeutic interventions and can diagnose early intraoperative complications, such as the embolization of large vessels or development of pulmonary hypertension. In this review, directed at clinicians who manage TEE during LT, we show why the procedure merits a place in challenging anaesthetic environment and how it can provide essential information in the perioperative management of compromised patients undergoing this very complex surgical procedure.

Survey of hemostasis management and transfusion in liver transplantation

OBJECTIVE

To determine the management of haemostasis and transfusion practice in the field of liver transplantation in Spain.

METHODS

A questionnaire was developed for physicians in anaesthesiology of all centres performing liver transplantation in Spain. The information required made reference to the 12 months prior to its distribution, from January 1 to December 31, 2011.

RESULTS

Data were collected from 24 centres in which liver transplantation is performed in Spain. Only 46% reported that they had protocols or practice guidelines for the management of haemostasis, and 83% of hospitals responded that they knew the percentage of transfused patients, but only 57% knew the mean transfusion. Regarding the degree of satisfaction with the management of haemostasis/coagulation, 50% said they were not satisfied. Thromboelastometry was used as an additional method of preoperative monitoring in only 8% of the centres and intra-operatively in one-third. Less than half (46%) of the centres performed preoperative correction of coagulation deficits based on conventional tests. The mean number of packed red cells used was ≤4 in 57% of centres. Consumption of fresh frozen plasma was highly variable, while 100% of centres consumed less than 4 pools of platelets per patient.

CONCLUSIONS

There is a wide variability in the management of haemostasis and transfusion practice among Spanish centres. There are no guidelines or they are not widely used. The mean use of transfused blood products remain high. There was a decrease in centres using new methods of monitoring.

Viscoelastic Methods of Blood Clotting Assessment - A Multidisciplinary Review

Viscoelastic methods (VEM) made available the bedside assessment of blood clotting. Unlike standard laboratory tests, the results are based on the whole blood coagulation and are available in real time at a much faster turnaround time. In combination with our new knowledge about pathophysiology of the trauma-induced coagulopathy, the goal-oriented treatment protocols have been recently proposed for the initial management of bleeding in trauma victims. Additionally, the utility of viscoelastic monitoring devices has been proved even outside this setting in cardiosurgical patients or those undergoing liver transplantation. Many other situations were described in literature showing the potential use of bedside analysis of coagulation for the management of bleeding or critically ill patients. In the near future, we may expect further improvement in current bedside diagnostic tools enabling not only the assessment of secondary hemostasis but also the platelet aggregation. More sensitive assays for new anticoagulants are underway. Aim of this review is to offer the reader a multidisciplinary overview of VEM and their potential use in anesthesiology and critical care.

Relevance of ADAMTS13 to liver transplantation and surgery

A disintegrin-like and metalloproteinase with thrombospondin type-1 motifs 13 (ADAMTS13) specifically cleaves unusually-large von Willebrand factor (VWF) multimers under high shear stress, and down-regulates VWF function to form platelet thrombi. Deficiency of plasma ADAMTS13 activity induces a life-threatening systemic disease, termed thrombotic microangiopathy (TMA) including thrombotic thrombocytopenic purpura (TTP). Children with advanced biliary cirrhosis due to congenital biliary atresia sometimes showed pathological features of TMA, with a concomitant decrease of plasma ADAMTS13 activity. Disappearance of their clinical findings of TTP after successful liver transplantation suggested that the liver is a major organ producing plasma ADAMTS13. In situ hybridization analysis showed that ADAMTS13 was produced by hepatic stellate cells. Subsequently, it was found that ADADTS13 was not merely responsible to development of TMA and TTP, but also related to some kinds of liver dysfunction after liver transplantation. Ischemia-reperfusion injury and acute rejection in liver transplant recipients were often associated with marked decrease of ADAMTS13 and concomitant formation of unusually large VWF multimers without findings of TMA/TTP. The similar phenomenon was observed also in patients who underwent hepatectomy for liver tumors. Imbalance between ADAMTS13 and VWF in the hepatic sinusoid might cause liver damage due to microcirculatory disturbance. It can be called as “local TTP like mechanism” which plays a crucial role in liver dysfunction after liver transplantation and surgery.