What we should know about portal vein thrombosis in cirrhotic patients: A changing perspective

A new model of portal vein thrombosis in rats with cirrhosis induced by partial portal vein ligation plus carbon tetrachloride and intervened with rivaroxaban

BACKGROUND AND AIMS

Portal vein thrombosis (PVT) is a common complication of liver cirrhosis that can aggravate portal hypertension. However, there are features of both PVT and cirrhosis that are not recapitulated in most current animal models. In this study, we aimed to establish a stable animal model of PVT and cirrhosis, intervene with anticoagulant, and explore the related mechanism.

METHODS

First, 49 male SD rats received partial portal vein ligation (PPVL), and 44 survival rats were divided into 6 groups: PPVL control group; 4-week, 6 -week, 8-week, and 10-week model group; and the rivaroxaban (RIVA)-treated group. The rats were intoxicated with or without carbon tetrachloride (CCl4) for 4-10 weeks. Seven normal rats were used as the normal controls. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and parameters for blood coagulation were all assayed with kits. Liver inflammation, collagen deposition and hydroxyproline (Hyp) levels were also measured. The extrahepatic macro-PVT was observed via portal vein HE staining, etc. The intrahepatic microthrombi was stained via fibrin immunohistochemistry. The portal blood flow velocity (PBFV) and diameter were detected via color Doppler ultrasound. Vascular endothelial injury was evaluated by von Willebrand Factor (vWF) immunofluorescence. Fibrinolytic activity was estimated by western blot analysis of fibrin and plasminogen activator inhibitor-1 (PAI-1).

RESULTS

After PPVL surgery and 10 weeks of CCl4 intoxication, a rat model that exhibited characteristics of both cirrhosis and extra and intrahepatic thrombi was established. In cirrhotic rats with PVT, the PBFV decreased, both factors of pro- and anti-coagulation decreased, but with relative hypercoagulable state, vascular endothelial injured, and fibrinolytic activity decreased. RIVA-treated rats had improved coagulation function, increased PBFV and attenuated thrombi. This effect was related to the improvements in endothelial injury and fibrinolytic activity.

CONCLUSIONS

A new rat model of PVT with cirrhosis was established through partial portal vein ligation plus CCl4 intoxication, with the characteristics of macrothrombi at portal veins and microthrombi in hepatic sinusoids, as well as liver cirrhosis. Rivaroxaban could attenuate PVT in cirrhosis in the model rats. The underlying mechanisms of PVT formation in the rat model and pharmacological action of rivaroxaban are related to the regulation of portal blood flow, coagulant factors, and vascular endothelial cell function.

Predictive model for non-malignant portal vein thrombosis associated with cirrhosis based on inflammatory biomarkers

BACKGROUND

Portal vein thrombosis (PVT), a complication of liver cirrhosis, is a major public health concern. PVT prediction is the most effective method for PVT diagnosis and treatment.

AIM

To develop and validate a nomogram and network calculator based on clinical indicators to predict PVT in patients with cirrhosis.

METHODS

Patients with cirrhosis hospitalized between January 2016 and December 2021 at the First Hospital of Lanzhou University were screened and 643 patients with cirrhosis who met the eligibility criteria were retrieved. Following a 1:1 propensity score matching 572 patients with cirrhosis were screened, and relevant clinical data were collected. PVT risk factors were identified using the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression analysis. Variance inflation factors and correlation matrix plots were used to analyze multicollinearity among the variables. A nomogram was constructed to predict the probability of PVT based on independent risk factors for PVT, and its predictive performance was verified using a receiver operating characteristic curve (ROC), calibration curves, and decision curve analysis (DCA). Finally, a network calculator was constructed based on the nomograms.

RESULTS

This study enrolled 286 cirrhosis patients with PVT and 286 without PVT. LASSO analysis revealed 13 variables as strongly associated with PVT occurrence. Multivariate logistic regression analysis revealed nine indicators as independent PVT risk factors, including etiology, ascites, gastroesophageal varices, platelet count, D-dimer, portal vein diameter, portal vein velocity, aspartate transaminase to neutrophil ratio index, and platelet-to-lymphocyte ratio. LASSO and correlation matrix plot results revealed no significant multicollinearity or correlation among the variables. A nomogram was constructed based on the screened independent risk factors. The nomogram had excellent predictive performance, with an area under the ROC curve of 0.821 and 0.829 in the training and testing groups, respectively. Calibration curves and DCA revealed its good clinical performance. Finally, the optimal cutoff value for the total nomogram score was 0.513. The sensitivity and specificity of the optimal cutoff values were 0.822 and 0.706, respectively.

CONCLUSION

A nomogram for predicting PVT occurrence was successfully developed and validated, and a network calculator was constructed. This can enable clinicians to rapidly and easily identify high PVT risk groups.

Molecular Mechanisms Underlying Vascular Liver Diseases: Focus on Thrombosis

Vascular liver disorders (VLDs) comprise a wide spectrum of clinical-pathological entities that primarily affect the hepatic vascular system of both cirrhotic and non-cirrhotic patients. VLDs more frequently involve the portal and the hepatic veins, as well as liver sinusoids, resulting in an imbalance of liver homeostasis with serious consequences, such as the development of portal hypertension and liver fibrosis. Surprisingly, many VLDs are characterized by a prothrombotic phenotype. The molecular mechanisms that cause thrombosis in VLD are only partially explained by the alteration in the Virchow's triad (hypercoagulability, blood stasis, and endothelial damage) and nowadays their pathogenesis is incompletely described and understood. Studies about this topic have been hampered by the low incidence of VLDs in the general population and by the absence of suitable animal models. Recently, the role of coagulation imbalance in liver disease has been postulated as one of the main mechanisms linked to fibrogenesis, so a novel interest in vascular alterations of the liver has been renewed. This review provides a detailed analysis of the current knowledge of molecular mechanisms of VLD. We also focus on the promising role of anticoagulation as a strategy to prevent liver complications and to improve the outcome of these patients.

Prevalence of portal vein and splanchnic venous thrombosis in dogs with chronic hepatitis

OBJECTIVES

Alterations in haemostasis have been described in dogs and humans with chronic hepatitis. Portal vein thrombosis is a recognised complication of chronic hepatitis in humans; however, its prevalence in dogs with chronic hepatitis has not been reported. We aimed to estimate the prevalence of, and describe clinical and laboratory data of dogs with chronic hepatitis and portal vein thrombosis and splanchnic venous thrombosis.

MATERIALS AND METHODS

Retrospective cross-sectional study. Medical records of dogs admitted to a veterinary teaching hospital between 2009 and 2019 were reviewed. Dogs were included if chronic hepatitis was histopathologically confirmed, and if diagnostic imaging or necropsy indicated the presence of thrombosis. Clinical and laboratory data (i.e. haematology, biochemistry, coagulation panels) were recorded. Descriptive statistics were used to characterise dogs with and without thrombosis.

RESULTS

Records from 136 dogs with chronic hepatitis were identified. Three of these dogs, 2.2% (95% confidence interval: 0.8 to 6.3%) all females, were diagnosed with portal vein thrombosis. Five dogs in total, (3.7%; 95% confidence interval: 1.6 to 8.3%), including three with portal vein thrombosis, all females, were diagnosed with splanchnic venous thrombosis. Dogs with portal vein and splanchnic venous thrombosis often had hyperbilirubinaemia, increased serum gamma-glutamyl transferase activity, and decreased plasma antithrombin 3 activity. They also had relatively high alternative Child-Pugh scores for dogs (median 6 out of 13).

CLINICAL SIGNIFICANCE

Portal vein and splanchnic venous thrombosis are potentially serious complications that were identified in a relatively low proportion of dogs with chronic hepatitis.

Portal vein thrombosis in cirrhosis: A literature review

Portal Vein Thrombosis (PVT), a common complication of advanced liver disease, is defined as an obstruction of the portal vein due to thrombus formation that can extend to the superior mesenteric and splenic veins. It was believed that PVT occurred predominantly due to prothrombotic potential. However, recent studies have shown that decreased blood flow related to portal hypertension appears to increase PVT risk as per Virchow's triad. It is well known that there is a higher incidence of PVTs in cirrhosis with a higher MELD and Child Pugh score. The controversy for management of PVTs in cirrhotics lies in the individualized assessment of risks versus benefits of anticoagulation, since these patients have a complex hemostatic profile with both bleeding and procoagulant propensities. In this review, we will systematically compile the etiology, pathophysiology, clinical features, and management of portal vein thrombosis in cirrhosis.

Reconstructing the portal vein through a posterior pancreatic tunnel: New choice for portal vein thrombosis during liver transplantation

BACKGROUND

Thrombectomy and anatomical anastomosis (TAA) has long been considered the optimal approach to portal vein thrombosis (PVT) in liver transplantation (LT). However, TAA and the current approach for non-physiological portal reconstructions are associated with a higher rate of complications and mortality in some cases.

AIM

To describe a new choice for reconstructing the portal vein through a posterior pancreatic tunnel (RPVPPT) to address cases of unresectable PVT.

METHODS

Between August 2019 and August 2021, 245 adult LTs were performed. Forty-five (18.4%) patients were confirmed to have PVT before surgery, among which seven underwent PV reconstruction via the RPVPPT approach. We retrospectively analyzed the surgical procedure and postoperative complications of these seven recipients that underwent PV reconstruction due to PVT.

RESULTS

During the procedure, PVT was found in all the seven cases with significant adhesion to the vascular wall and could not be dissected. The portal vein proximal to the superior mesenteric vein was damaged in one case when attempting thrombolectomy, resulting in massive bleeding. LT was successfully performed in all patients with a mean duration of 585 min (range 491-756 min) and mean intraoperative blood loss of 800 mL (range 500-3000 mL). Postoperative complications consisted of chylous leakage (n = 3), insufficient portal venous flow to the graft (n = 1), intra-abdominal hemorrhage (n = 1), pulmonary infection (n = 1), and perioperative death (n = 1). The remaining six patients survived at 12-17 mo follow-up.

CONCLUSION

The RPVPPT technique might be a safe and effective surgical procedure during LT for complex PVT. However, follow-up studies with large samples are still warranted due to the relatively small number of cases.

Significance of altered anticoagulant proteins and D-dimer in cirrhotic portal vein thrombosis: relation to the degree of liver dysfunction

Aim of the study

Portal vein thrombosis (PVT) is a well-known consequence of cirrhosis. Its pathophysiology is complex, with possible downstream hepatic decompensation. This study was conducted to describe the changes of protein C (PC), protein S (PS) and D-dimer blood levels associated with PVT formation in cirrhosis and the relation to the degree of liver dysfunction.

Material and methods

This was a case-control study that included 50 cirrhotic patients who presented with acute de novo non-malignant PVT and 50 cirrhotic patients without PVT as a control group. The severity of liver disease was classified as per the Child-Turcotte-Pugh (CTP) score. Doppler ultrasonography identified acute portal vein occlusion, and dynamic contrast-enhanced computed tomography confirmed the extent and nature of PVT. Blood PC, PS and D-dimer levels were measured using enzyme-linked immunosorbent assay.

Results

PC and PS levels were significantly lower, and the D-dimer level was significantly higher, in cirrhotic patients with PVT compared to the control group. PC and PS levels were significantly decreased in patients with higher CTP score of both groups. The D-dimer level did not vary significantly with the degree of liver dysfunction in patients of either group. PC, PS and D-dimer at the cut-off points of ≤ 77 IU/dl, ≤ 63 IU/dl, and > 300 ng/ml, respectively, significantly suggested PVT occurrence.

Conclusions

Alteration of the anticoagulant proteins and D-dimer contributed to PVT formation in cirrhotic patients and could help stratify the degree of liver dysfunction. Blood level of these hemostatic proteins could be incorporated into a probability score for early diagnosis and treatment of PVT in cirrhosis.

Portal Vein Thrombosis in Cirrhosis

Patients with cirrhosis of the liver are at high risk of developing portal vein thrombosis (PVT), which has a complex, multifactorial cause. The condition may present with a myriad of symptoms and can occasionally cause severe complications. Contrast-enhanced computed tomography (CT) is the gold standard for the diagnosis of PVT. There are uncertainties regarding the effect on PVT and its treatment outcome in patients with cirrhosis. The main challenge for managing PVT in cirrhosis is analyzing the risk of hemorrhage compared to the risk of thrombus extension leading to complications. All current knowledge regarding non-tumor PVT in cirrhosis, including epidemiology, risk factors, classification, clinical presentation, diagnosis, impact on natural history, and treatment, is discussed in the present article.

Influence of portal vein occlusion on portal flow and liver elasticity in an animal model

Hepatic fibrosis causes an increase in liver stiffness, a parameter measured by elastography and widely used as a diagnosis method. The concomitant presence of portal vein thrombosis (PVT) implies a change in hepatic portal inflow that could also affect liver elasticity. The main objective of this study is to determine the extent to which the presence of portal occlusion can affect the mechanical properties of the liver and potentially lead to misdiagnosis of fibrosis and hepatic cirrhosis by elastography. Portal vein occlusion was generated by insertion and inflation of a balloon catheter in the portal vein of four swines. The portal flow parameters peak flow (PF) and peak velocity magnitude (PVM) and liver mechanical properties (shear modulus) were then investigated using 4D-flow MRI and MR elastography, respectively, for progressive obstructions of the portal vein. Experimental results indicate that the reduction of the intrahepatic venous blood flow (PF/PVM decreases of 29.3%/8.5%, 51.0%/32.3% and 83.3%/53.6%, respectively) measured with 50%, 80% and 100% obstruction of the portal vein section results in a decrease of liver stiffness by 0.8% ± 0.1%, 7.7% ± 0.4% and 12.3% ± 0.9%, respectively. While this vascular mechanism does not have sufficient influence on the elasticity of the liver to modify the diagnosis of severe fibrosis or cirrhosis (F4 METAVIR grade), it may be sufficient to attenuate the increase in stiffness due to moderate fibrosis (F2-F3 METAVIR grades) and consequently lead to false-negative diagnoses with elastography in the presence of PVT.

Portal vein thrombosis: A concise review (Review)

Portal vein thrombosis (PVT) is a frequent complication in cirrhotic patients, but it may also exist as a basic vascular condition even without any liver damage. Local and systemic factors play a significant role in the pathogenesis of PVT; yet, in practice, more than one factor may be identified. PVT can be considered a result of liver fibrosis and hepatic insufficiency. The JAK2 mutation has been accepted as a factor producing PVT. In general, the anticoagulants are recommended but this therapy should be used carefully in treating patients that associate coagulopathy or thrombocytopenia and esophageal varices. Acute PVT without bowel infarction has a good prognosis. In liver cirrhosis, the mortality due to hemorrhage is higher than in chronic PVT. Therefore, for the patients with PVT, the survival rate is decreased by 55% in two years, due to hepatic insufficiency. Regarding the treatment, LMWH (low molecular weight heparine) is the most utilized in patients with cirrhosis, non-malignancies, infections, or those who are awaiting a liver transplant. DOACs (direct-acting oral anticoagulants) may be used in the rest of the medical conditions, being safe and equal to LMWH.

Portal vein thrombosis and renal dysfunction: a national comparative study of liver transplant recipients for NAFLD versus alcoholic cirrhosis

The prevalence of portal vein thrombosis (PVT), renal dysfunction (RD), and simultaneous PVT/RD in liver transplantation (LT) is poorly understood. We analyzed the prevalence of PVT, RD, simultaneous PVT/RD, and the outcomes of adult recipients of LT for nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) between 2006 and 2016 in the United States. We found that the prevalence of PVT (7.2% → 11.3%), RD (33.8% → 39.2%), and simultaneous PVT/RD (2.4% → 4.5%) has increased significantly over the study period (all P‐values <0.05). NAFLD patients had a higher proportion of PVT (14.8% vs. 9.2%), RD (45.0% vs. 42.1%), and simultaneous PVT/RD (6.5% vs. 3.9%; all P‐values <0.05). 90‐day mortality was 3.8%, 6.3%, 6.8%, and 9.8% for PVT(−)/RD(−), PVT(−)/RD(+), PVT(+)/RD(−), and PVT(+)/RD(+) recipients, respectively (P < 0.01). 5‐year survival was 82.1%, 75.5%, 74.8%, and 71.1% for PVT(−)/RD(−), PVT(−)/RD(+), PVT(+)/RD(−), and PVT(+)/RD(+) recipients, respectively (P < 0.05). In conclusion, the prevalence of PVT, RD, and simultaneous PVT/RD has increased among LT recipients, especially for those with NAFLD. The short‐ and long‐term outcomes of recipients with PVT, RD, and simultaneous PVT/RD were inferior to patients without those risk factors irrespective of their indication for LT. No differences in patient outcomes were found between ALD and NAFLD recipients after stratification by risk factors.

Treatment of portal vein thrombosis: an updated narrative review

Portal vein thrombosis (PVT) is the most frequent among the splanchnic vein thrombosis, accounting for 90% of cases. More than half of PVT are provoked by liver cirrhosis, solid cancer or myeloproliferative neoplasms. The remaining cases are non-malignant non-cirrhotic PVT and include either unprovoked events or thrombosis secondary to other less common risk factors (e.g. abdominal surgery, intrabdominal inflammations/infections, or hormonal stimuli). Anticoagulant therapy in patients with acute symptomatic PVT should be started early after diagnosis, if no active bleeding, to obtain greater vessel recanalization and reduce the occurrence of portal-hypertension related complications. Gastroesophageal varices do not represent a contraindication to anticoagulant treatment, as long as adequate measures have been undertaken for the prophylaxis of gastroesophageal bleeding. Different treatment options (unfractionated or low molecular weight heparin, vitamin K antagonists and direct oral anticoagulants [DOACs]) can be considered. In this narrative review we will discuss the treatment of PVT in the three most common scenarios (cirrhosis-associated, cancer-associated and non-malignant non-cirrhotic PVT). We will also discuss the role of the DOACs and summarise recent guidelines on this topic.

Efficacy and safety of anticoagulants in liver cirrhosis patients with portal vein thrombosis: A meta-analysis

OBJECTIVE

To investigate the efficacy and safety of anticoagulants in liver cirrhosis patients with portal vein thrombosis (PVT).

METHODS

PubMed, BioMed Central, Cochrane Library and Web of Science were retrieved to identify relevant literature. Forest plots were applied to display the results of the meta-analysis. The odds ratios (ORs) were used as the effect index for the enumeration data, and the effect size was expressed as 95% confidence intervals (CIs). Publication bias was evaluated by funnel plots and Egger's test.

RESULTS

Eight articles included 225 patients with liver cirrhosis and PVT receiving anticoagulants and 232 not receiving anticoagulants. The data demonstrated that the recanalization rate of PVT was significantly higher in patients with anticoagulant treatment than in patients without anticoagulant treatment (OR=5.60; 95% CI: 3.40-9.22; P<0.001). The exacerbation risk of PVT was significantly lower in patients with anticoagulant treatment than in patients without anticoagulant treatment (OR=0.15; 95% CI: 0.04-0.54; P<0.001). A significantly lower portal hypertension bleeding effect was observed in patients with anticoagulant treatment than in patients without anticoagulant treatment (OR=0.21; 95% CI: 0.10-0.45; P<0.001). Low molecular weight heparins (LMWH) were more effective in preventing the PVT exacerbation in liver cirrhosis patients with PVT than warfarin (OR=0.16; 95% CI: 0.08-0.35).

CONCLUSIONS

Anticoagulants were effective and safe in treating patients with liver cirrhosis and PVT as they could increase the PVT recanalization rate and decrease the risks of PVT exacerbation and portal hypertension bleeding.

Janus Kinase-2 Mutation Associated Portal Vein Thrombosis Complicating Liver Cirrhosis and Hepatocellular Carcinoma

Background:

Portal vein thrombosis (PVT) might be a catastrophic event complicating liver cirrhosis and hepatocellular carcinoma (HCC).

Aim:

role of JAK2 RS V617F mutation as a risk factor for PVT development in liver cirrhosis and HCC.

Methods:

A case control study conducted on 100 PVT patients (76 HCC and 24 liver cirrhosis) additionally, 100 healthy individuals used as a control group. PVT was diagnosed incidentally by Doppler ultrasound during routine follow-up HCC screening. ProthrombinG20210A mutation, MTHFR mutation, Factor V Leiden mutation (VFL), antithrombin III (ATIII), protein C, S, and antiphospholipid antibodies, along with JAK2 RS V617F mutation by real-time polymerase chain reaction all were analyzed.

Results:

Patients with PVT were significantly older (p<0.001), thrombocytopenic (p<0.001), with high alkaline phosphatase (p<0.001). JAK2 RS V617F mutation was found in 28/100 (28%) in idiopathic PVT complicating liver cirrhosis and hepatocellular carcinoma. Cases with positive JAK2 rs V617F mutation were significantly accompanied by protein S deficiency (P 0.03), LA absence (p 0.06), and high frequency of ascites (P 0.03). While, the MTHFR heterozygous mutation (p0.001), ATIII (P 0.02), and VFL (P 0.01) were more frequent with negative JAK2 rs V617F mutation. The comparison between demographic data and thrombophilic parameters in PVT cases revealed that no significant differences were recorded except for male gender, Diabetes Mellitus, splenomegaly significantly increased among HCC cases (p<0.05).

Conclusions:

JAK2 rs V617F mutation must be considered in any case of PVT with liver cirrhosis and hepatocellular carcinoma without identified thrombophilic risk factors, with potential considerations of evolving myeloproliferative disorders. New diagnostic and therapeutic implications are still awaited.

Portal vein surgical treatment on non-tumoral portal vein thrombosis in liver transplantation: Systematic Review and Meta-Analysis

Non-tumoral portal vein thrombosis (PVT) is associated with higher morbidity and mortality in liver transplantation (LT). In this study, we aimed to evaluate the impact of PVT in LT outcomes and analyze the types of surgical techniques used for dealing with PVT during LT. A systematic review was conducted in Cochrane, MEDLINE, and EMBASE databases, selecting articles from January 1990 to December 2019. The MESH-terms used were ("Portal Vein"[Mesh] AND "Thrombosis"[Mesh] NOT "Neoplasms"[Mesh]) AND ("Liver Transplantation"[Mesh]). The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) recommendation was used, and meta-analysis was performed with Review Manager Version 5.3 software. A total of 1,638 articles were initially found: 488 in PubMed, 289 in Cochrane Library, and 861 in EMBASE, from which 27 were eventually selected for the meta-analysis. Surgery time of LT in patients with PVT was longer than in patients without LT (p<0.0001). Intraoperative red blood cell (p<0.00001), fresh frozen plasma (p=0.01), and platelets (p=0.03) transfusions during LT were higher in patients with PVT. One-year (odds ratio [OR] 1.17; p=0.002) and 5-year (OR 1.12; p=0.01) patient survival after LT was worse in the PVT group. Total occlusive PVT presented higher mortality (OR 3.70; p=0.00009) and rethrombosis rates (OR 3.47 [1.18-10.21]; p=0.02). PVT Yerdel III/IV classification exhibited worse 1-year [2.04 (1.21-3.42); p=0.007] and 5-year [0.98 (0.59-1.62); p=0.93] patient survival. Thrombectomy with primary anastomosis was associated with better outcomes. LT in patients with non-tumoral PVT demands more surgical time, needs more intraoperative transfusion, and presents worse 1- and 5-year patient survival. Total occlusive PVT and Yerdel III/IV PVT classification were associated with higher mortality. (PROSPERO, registration number: CRD42020132915).

Portal vein thrombosis in cirrhosis: Why a well-known complication is still matter of debate

Portal vein thrombosis (PVT) represents a well-known complication during the natural course of liver cirrhosis (LC), ranging from asymptomatic cases to life-threating conditions related to portal hypertension and hepatic decompensation. Portal flow stasis, complex acquired hypercoagulable disorders and exogenous factors leading to endothelial dysfunction have emerged as key factors for PVT development. However, PVT occurrence remains unpredictable and many issues regarding its natural history, prognostic significance and treatment are still elusive. In particular although spontaneous resolution or disease stability occur in most cases of PVT, factors predisposing to disease progression or recurrence after spontaneous recanalization are not clarified as yet. Moreover, PVT impact on LC outcome is still debated, as PVT may represent itself a consequence of liver fibrosis and hepatic dysfunction progression. Anticoagulation and transjugular intrahepatic portosystemic shunt are considered safe and effective in this setting and are recommended in selected cases, even if the safer therapeutic option and the optimal therapy duration are still unknown. Nevertheless, their impact on mortality rates should be addressed more extensively. In this review we present the most debated questions regarding PVT, whose answers should come from prospective cohort studies and large sample-size randomized trials.

Safety of direct oral anticoagulants in patients with cirrhosis: a systematic review and meta-analysis

INTRODUCTION

Direct oral anticoagulants (DOACs) are effective treatment for venous thromboembolism. However, safety data in patients with cirrhosis are limited. We conducted a systematic review and meta-analysis to evaluate the safety of DOACs compared with warfarin or low-molecular weight heparin in patients with cirrhosis.

METHODS

A systematic literature search was performed using MEDLINE and EMBASE from inception up to June 2018. We included prospective and retrospective studies involving adults ≥18 years with cirrhosis in whom anticoagulants were indicated for any indications. Primary outcome was all-cause bleeding events. Secondary outcome was major bleeding. Pooled risk ratio, pooled odd ratios and 95% confidence intervals (CIs) were calculated using random-effects model.

RESULTS

Five studies with a total of 447 patients were included in the analysis. When compared with controls, the use of DOACs in cirrhotic patients did not show a significant difference in all-cause bleeding (risk ratio 0.72; 95% CI, 0.32-1.63). There was also no significant difference in major bleeding between both groups (odd ratio 0.46; 95% CI, 0.10-2.09).

CONCLUSIONS

Our study demonstrates that, compared to those who were treated with traditional anticoagulants, cirrhotic patients who were treated with DOACs had no significant increase risk of all-cause bleeding and major bleeding.

The risk factors of portal vein thrombosis in patients with liver cirrhosis

This study was designed to identify and assess risk factors for portal vein thrombosis (PVT) in patients with cirrhosis. A total of 98 cirrhosis patients with PVT were identified and 101 cirrhosis patients without PVT were chosen as the control group in this retrospective study. Several variables were measured and the two groups PVT and non-PVT were compared statistically. PVT was identified in 98 patients (10%). Significant differences in hematocrit, international normalized ratio, albumin, bilirubin and glucose were determined between the groups (P<0.05). Out of the thrombophilic risk factors in the patients with PVT factor V Leiden was identified in 8.8%, prothrombin gene 6.6% and methylenetetrahydrofolate reductase 2.2%. There was no difference in survival time between groups (P>0.05).

Clinical Impact and Safety of Anticoagulants for Portal Vein Thrombosis in Cirrhosis

OBJECTIVES

Portal vein thrombosis (PVT) is a frequent complication of cirrhosis. Benefit, safety, and duration of anticoagulant treatment in this setting are controversial issues. The aim of this study was to analyze the course of PVT in a large cohort of cirrhotic patients undergoing or not anticoagulation therapy.

METHODS

The data of 182 patients who presented between January 2008 and March 2016 with cirrhosis and PVT with at least 3 months of follow-up after the first PVT detection were analyzed. Eighty-one patients received anticoagulants and 101 were untreated per physician discretion.

RESULTS

The extension of the thrombosis decreased by >50% in 46 (56.8%, with complete recanalization in 31/46) patients under anticoagulation and in 26 (25.7%) untreated patients. Of the 46 patients who underwent recanalization, 17 (36%) suffered recurrent thrombosis after stopping anticoagulation therapy. Kaplan-Meier analysis showed a higher survival rate in the treated group (p = 0.010). At multivariate analysis, anticoagulation was an independent factor associated with longer survival (HR:0.30, CI:0.10-0.91, p = 0.014). The Child-Turcotte-Pugh classes B/C negatively influenced survival (hazard ratio, (HR):3.09, confidence interval (CI):1.14-8.36, p = 0.027 for Child-Turcotte-Pugh B and HR:9.27, CI:2.67-32.23, p < 0.001 for Child-Turcotte-Pugh C). Bleeding complications occurred in 22 (21.8%) untreated and 16 (19.7%) treated patients, but in only four cases was it judged to be related to the anticoagulant treatment. No death was reported as a consequence of the bleeding events.

CONCLUSIONS

Anticoagulant treatment is a safe and effective treatment leading to partial or complete recanalization of the portal venous system in 56.8% of cases, improving the survival of patients with cirrhosis and PVT. Discontinuation of the therapy is associated with a high rate of PVT recurrence.

Bacterial translocation in patients with liver cirrhosis: physiology, clinical consequences, and practical implications

The gut liver axis is an operative unit that works to protect the human body against potentially harmful substances and microorganisms, maintaining the homeostasis of the immune system. Liver cirrhosis profoundly alters this complex system. The intestine becomes more permeable allowing the translocation of bacteria, bacterial products and fragments into the portal circulation, triggering an abnormal local and systemic inflammatory response and a condition of perpetual immunologic alarm. This immune-inflammatory disorder related to dysbiosis is involved in the development of liver damage and liver cirrhosis complications and increases intestinal permeability in a vicious circle. Areas covered: The most relevant studies on bacterial translocation, the mechanism of intestinal barrier dysfunction and its consequences in patients with liver cirrhosis have been revised through a PubMed search. Data have been discussed with particular regard to their significance in clinical practice. Expert commentary: The assessment of bacterial translocation and intestinal permeability is not currently used in clinical practice but may be useful to stratify patients' prognosis.

Progress in research of venous thromboembolism in hospitalized patients with digestive system diseases

Hospitalized patients with digestive system diseases are at high risk of venous thromboembolism (VTE) due to a variety of factors such as advanced age, prolonged bed rest, medication and so on. VTE can affect the quality of life of patients, the number of days of hospitalization, and the cost of treatment and even threaten their life. This article gives a brief overview of the pathogenesis, risk factors, assessment tools, and preventive methods for VTE to promote better prevention of this disease.

Risk factors for portal vein thrombosis in cirrhotic patients: A meta-analysis

AIM

To identify the risk factors for portal vein thrombosis (PVT) in cirrhotic patients.

METHODS

We searched the PubMed, CNKI and Wanfang Databases up to Aug 2015 to retrieve case-controlled studies about the risk factors for PVT in cirrhotic patients for meta-analysis. The odds ratio or weighted mean difference (WMD) of each risk factor was estimated and the 95% confidence interval (95%CI) was calculated. RevMan 5.0 software provided by the Library of Cochrane was used for meta-analysis.

RESULTS

Nine case-controlled studies were included. The risk factors for PVT included D-dimer (WMD = 0.34, 95%CI: 0.21-0.46), portal vein diameter (WMD = 1.67, 95%CI: 1.36-1.97), portal venous flow [WMD = -2.32, 95%CI: -3.63-(-1.01)], and splenic thickness (WMD = 8.57, 95%CI: 4.14-12.99). There were no significant differences between patients with and without PVT in terms of sex, age, platelet, prothrombin time, activated partial thromboplastin time, and fibrinogen.

CONCLUSION

The risk factors for PVT in cirrhotic patients include D-dimer, portal vein diameter, portal venous flow, and splenic thickness.

Incidence and clinical presentation of portal vein thrombosis in cirrhotic patients

BACKGROUND

Portal vein thrombosis (PVT) is due to many risk factors, but its pathogenesis is still not clearly understood. To identify the risk factors for PVT, we analyzed the clinical characteristics and complications associated with PVT in cirrhotic patients.

METHODS

We studied patients with liver cirrhosis who were admitted to our unit from April 2009 to December 2014. The patients were divided into the PVT and non-PVT groups, and were compared by variables including gender, age, the etiology of cirrhosis, stage of cirrhosis, complications, imaging, and treatment.

RESULTS

PVT was found in 45 (9.8%) of 461 cirrhotic patients admitted to our hospital. Most patients (45.9%) had hepatitis B virus (HBV)-related cirrhosis, with a similar distribution of etiologies between the groups. However, there was no positive relationship between PVT and etiologies of cirrhosis. Most patients (71.5%) were in the stage of hepatic decompensation. No statistically significant differences were found in complications including esophageal varices, ascites, and hepatic encephalopathy between the groups. However, there was a significant positive correlation between hepatocellular carcinoma (HCC) and PVT (P<0.01). In 30 patients with PVT, thrombosis occurred in the portal vein and/or portal branches, 37.8% were diagnosed on ultrasound.

CONCLUSIONS

The incidence of PVT was 9.8%, mainly in patients with HBV-related cirrhosis. The development of PVT was associated with the severity of liver disease and HCC.

Portal Vein Thrombosis Is a Risk Factor for Poor Early Outcomes After Liver Transplantation: Analysis of Risk Factors and Outcomes for Portal Vein Thrombosis in Waitlisted Patients

BACKGROUND

Portal vein thrombosis (PVT) is common in patients with cirrhosis, but the risk factors associated with PVT and its impact on outcomes following liver transplantation (LT) are not well defined. The objectives of this study were to determine the impact of PVT on post-LT patient and graft survival, waitlist outcomes, and the factors associated with PVT.

METHODS

A retrospective review of Organ Procurement and Transplant Network waitlist and LT data between 2002 and 2013 identified 48,570 patients undergoing their first LT, with 3321 (6.8%) reported to have PVT at LT.

RESULTS

Portal vein thrombosis was independently associated with increased 90-day mortality (odds ratio, 1.7; 95% confidence interval, 1.45-1.99; P < 0.001) and graft failure (odds ratio, 1.72; 95% confidence interval, 1.51-1.97; P < 0.001). Portal vein thrombosis at listing was not associated with lower transplant rates, or delisting for death, or deterioration. Only 31% of patients with PVT at LT had PVT reported at listing. The predictors of PVT at LT in patients without PVT at listing included: fatty or cryptogenic liver disease, ascites, diabetes mellitus, and obesity. "New" PVT at LT was associated with longer wait-time, higher rate of model of end-stage liver disease increase, and intermediate 90-day survival rates compared to patients with or without PVT at both listing and LT.

CONCLUSIONS

Portal vein thrombosis at LT is associated with early (90 days) mortality and graft failure, though a likely but undefined reporting bias for more extensive PVT would overstate estimated risks for all PVT. Further study is needed to better define risks of LT with PVT.

[Splanchnic venous thrombosis: A monocentric study of 31 cases]

INTRODUCTION

Splanchnic vein thrombosis (SVT) denotes thrombosis of the hepatic venous system and of the extrahepatic portal system. They are often the manifestation of one or more underlying prothrombotic states and can sometimes present problems of therapeutic care.

METHODS

We report a monocentric study of 31 cases of SVT observed in an internal medicine department between January 2006 and June 2012. Epidemiological, clinical, laboratory, therapeutic and outcome data were analyzed.

RESULTS

There was a slight female predominance (sex-ratio: 1.2). Median patient age at diagnosis was 37 years. Most cases of SVT were chronic (61.2%). Abdominal pain was the predominant symptom in acute cases while the predominant signs in chronic forms were signs of portal hypertension. Extrasplanchnic thrombosis was noted in seven patients (22.5%). Behçet's disease was the most common etiology (32%). The treatment was based on anticoagulants and corticosteroids and immunosuppressants when an inflammatory etiology was found. The average follow-up was 17 months. There were five deaths (16%).

CONCLUSION

SVT often reflects the existence of a disease and/or an underlying prothrombotic state that should be identified to adapt the treatment and to avoid fatal complications.

Changing common sense: Anti-platelet/coagulation therapy against cirrhosis

Until recently, anti-platelet/coagulation therapy had not been recommended for patients with cirrhosis. Although venous thrombosis is one of the representative complications of cirrhosis and ischemic disorders associated with atherosclerosis are not infrequent in cirrhotic patients, many clinicians have tended to hesitate to introduce anti-platelet/coagulation therapy to their patients. Undoubtedly, this is due to the increased risk of hemorrhagic diathesis in cirrhotic patients. However, accumulating evidence has revealed the benefits of anti-platelet/coagulation therapy for cirrhotic patients. In addition to the safety of the therapy carried out against cardiovascular diseases in cirrhotic patients, some clinical data have indicated its preventive effect on venous thrombosis. Moreover, the efficacy of anti-platelet/coagulation therapy against cirrhosis itself has been demonstrated both clinically and experimentally. The conceptual basis for application of anti-platelet/coagulation therapy against cirrhosis was constructed through two pathologic studies on intrahepatic thrombosis in cirrhotic livers. It may be better to use thrombopoietin-receptor agonists, which have been tested as a treatment for cirrhosis-related thrombocytopenia, in combination with anti-platelet drugs to reduce the risk of venous thrombosis. During the last decade, the World Journal of Gastroenterology, a sister journal of World Journal of Hepatology, has been one of the main platforms of active discussion of this theme.

Risk factors for nontumoral portal vein thrombosis in patients with liver cirrhosis

AIM: To identify the risk factors for nontumoral portal vein thrombosis (PVT) in patients with liver cirrhosis, and analyze the risk factors influencing the origin of PVT.

METHODS: We performed a retrospective study of 171 cirrhotic patients who were diagnosed with the disease at our hospital between September 2013 and December 2014. CT and color Doppler ultrasound were used to diagnose PVT. Of the patients included, 34 had PVT (experiment group), and 137 had not (control group). We collected the clinical features and laboratory indexes of the two groups. Logistic regression model (Wald test) was used to screen independent risk factors. The diagnostic performance of each risk factor was determined by plotting the ROC curve and determining the optimal threshold.

RESULTS: D-dimer (DD) (OR = 12.021, P = 0.001), width of main portal vein (OR = 28.574, P = 0.001), and portal vein velocity flow (OR = 19.568, P = 0.002) differed statistically between the two groups. Unconditional Logistic regression analysis indicated that DD and width of main portal vein were independent risk factors for PVT in cirrhosis patients, and their area under the curve was 0.669 and 0.742, respectively.

CONCLUSION: Width of main portal vein and DD are independent risk factors for PVT in cirrhosis patients. Wider diameter of main portal vein and higher DD are associated with a higher incidence of PVT.

Role of D-dimer in the Development of Portal Vein Thrombosis in Liver Cirrhosis: A Meta-analysis

BACKGROUND AND AIMS

A meta-analysis was performed to explore the role of the D-dimer in the development of portal vein thrombosis (PVT) in liver cirrhosis.

METHODS

All papers were searched via PubMed, EMBASE, China National Knowledge Infrastructure, Wan Fang, and VIP databases. A standardized mean difference (SMD) with 95% confidence interval (CI) was pooled.

RESULTS

Overall, 284 studies were initially identified, of which 21 were included. Cirrhotic patients with PVT had a significantly higher D-dimer concentration than those without PVT (pooled SMD = 1.249, 95%CI = 0.740-1.758). After the portal hypertension-related surgery, cirrhotic patients with PVT had a similar preoperative D-dimer concentration to those without PVT (pooled SMD = 0.820, 95%CI = -0.122-0.286), but a higher postoperative value of D-dimer concentration than those without PVT (pooled SMD = 2.505, 95%CI = 0.975-4.036). Notably, the D-dimer concentration at the 1 st postoperative day was similar between cirrhotic patients with and without PVT (pooled SMD = 0.137, 95%CI = -0.827-1.101), but that at the 7 th post-operative day was higher in cirrhotic patients with PVT than in those without PVT (pooled SMD = 1.224, 95%CI = 0.277-2.171).

CONCLUSION

D-dimer might be regarded as a diagnostic marker for PVT in liver cirrhosis. In addition, postoperative D-dimer testing is worthwhile for the diagnosis of PVT after portal hypertension-related surgery.

Progress in treatment of nontumoral portal vein thrombosis in liver cirrhosis

Portal vein thrombosis (PVT) is not uncommon in patients with liver cirrhosis, and it increases the risk of gastroesophageal hemorrhage. At present, pharmacological treatment is the preferred selection of management of PVT. Studies have shown that anticoagulation therapy does not increase the risk of gastrointestinal bleeding. Therefore, patients having indications should be given anticoagulation therapy as early as possible. When patients fail to respond to anticoagulation therapy, interventional therapy or surgery may be considered. This article reviews the recent knowledge about the treatment of PVT and discusses the progress in treatment of nontumoral PVT in liver cirrhosis.

Review article: portal vein obstruction--epidemiology, pathogenesis, natural history, prognosis and treatment

BACKGROUND

Portal vein obstruction may be due to portal vein thrombosis (PVT) or its sequale, the portal cavernoma. PVT is a common complication in liver cirrhosis, however, it may also occur as a primary vascular disorder, in absence of any liver disease.

AIM

To review the current knowledge on nomenclature, etiology, pathophysiology, clinical presentation, diagnostic workup and management of adult patients with obstruction in the portal vein, either as a primary vascular disease in adults, or as a complication of liver cirrhosis.

METHODS

A structured search in PubMed was performed using defined keywords (portal vein obstruction, extra-hepatic portal vein obstruction, PVT and portal cavernoma), including full text articles and abstracts in English language.

RESULTS

Several causes, operating both at local and systemic level, might play an important role in the pathogenesis of PVT. Frequently, more than one risk factor could be identified; however, occasionally no single factor is discernible. Diagnosis of portal vein obstruction depends on clinical presentation, imaging and laboratory investigations. Prompt treatment greatly affects the patient's outcome.

CONCLUSIONS

Portal vein obstruction occurring either due to thrombosis in the portal vein or due to the portal cavernoma, can contribute to significant morbidity and mortality in patients with or without cirrhosis. In recent years our understanding of etio-pathogenesis of portal vein obstruction has evolved tremendously, which has led to significant improvement in treatment outcomes. There are still areas where more studies are needed to better clarify the management issues of portal vein obstruction.

Etiology and Complications of Portal Vein Thrombosis

BACKGROUND

Portal venous occlusion represents a disorder with considerable clinical relevance. The underlying causes of portal vein thrombosis (PVT) are frequently multifactorial and include malignancies, progressive chronic liver diseases, processes localized to the epigastrium and hepatobiliary system, and acquired as well as inherited thrombophilia. The three main categorical groups are malignant thrombosis, cirrhotic PVT, and non-malignant, non-cirrhotic PVT.

METHODS

Review of the literature.

RESULTS

The site, the extent, its chronicity, and the course of thromboses characterize a relatively heterogeneous clinical presentation and the ensuing complications in affected patients. While the occlusion of the extrahepatic portal and splenic vein likely provokes mainly complications related to portal hypertension, mesenteric venous obstruction shows a high rate of complications and mortality due to intestinal infarction. Especially in patients with liver cirrhosis, special care is warranted with regard to PVTs due to their pathogenetic role and influence on patient survival.

CONCLUSION

This article aims to summarize the current opinion on etiologies, risk factors, and complications of this heterogeneous condition in adults.

Rational classification of portal vein thrombosis and its clinical significance

Portal vein thrombosis (PVT) is commonly classified into acute (symptom duration <60 days and absence of portal carvernoma and portal hypertension) and chronic types. However, the rationality of this classification has received little attention. In this study, 60 patients (40 men and 20 women) with PVT were examined using contrast-enhanced computed tomography (CT). The percentage of vein occlusion, including portal vein (PV) and superior mesenteric vein (SMV), was measured on CT image. Of 60 patients, 17 (28.3%) met the criterion of acute PVT. Symptoms occurred more frequently in patients with superior mesenteric vein thrombosis (SMVT) compared to those without SMVT (p<0.001). However, there was no significant difference in PV occlusion between patients with and without symptoms. The frequency of cavernous transformation was significantly higher in patients with complete PVT than those with partial PVT (p<0.001). Complications of portal hypertension were significantly associated with cirrhosis (p<0.001) rather than with the severity of PVT and presence of cavernoma. These results suggest that the severity of PVT is only associated with the formation of portal cavernoma but unrelated to the onset of symptoms and the development of portal hypertension. We classified PVT into complete and partial types, and each was subclassified into with and without portal cavernoma. In conclusion, neither symptom duration nor cavernous transformation can clearly distinguish between acute and chronic PVT. The new classification system can determine the pathological alterations of PVT, patency of portal vein and outcome of treatment in a longitudinal study.

Case reports of portal vein thrombosis and bile duct stenosis after stereotactic body radiation therapy for hepatocellular carcinoma

The aim of this study was to evaluate portal vein and bile duct toxicity after stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC). We retrospectively reviewed 63 patients who were administrated SBRT once for HCC. The prescribed doses were from 48 Gy in four fractions to 60 Gy in eight fractions. Portal vein thrombosis and bile duct stenosis were evaluated. The dose received by 2% of the volume (D2 ) of the portal vein and bile duct was calculated. Portal vein thrombosis was observed in three patients (4.8%). Common points of these patients were Child-Pugh class B and D2 of the portal vein 40 Gy or more (BED3 ≥200 Gy). Bile duct stenosis was observed in one patient (1.6%). The patient had a history of cholangiocarcinoma and left hepatic lobectomy. Portal vein thrombosis may be necessary to be considered when SBRT for HCC is administrated to patients in higher Child-Pugh class with higher D2 of the portal vein.

Nonselective β-blockers may induce development of portal vein thrombosis in cirrhosis

Currently, nonselective β-blockers (NSBBs) are commonly used for the prevention of variceal bleeding in liver cirrhosis. The beneficial effects of NSBBs are primarily attributed to the reduction in cardiac output by blockade of β1 receptors and vasoconstriction of the splanchnic circulation by the blockade of β2 receptors. The prognostic value of occlusive portal vein thrombosis (PVT) in cirrhotic patients has been increasingly recognized. The most important risk factor for the development of PVT in liver cirrhosis is the decreased portal vein inflow velocity. Collectively, we propose that the use of NSBBs potentially increases the development of portal vein thrombosis by reducing portal vein inflow velocity. The hypothesis should be confirmed by prospective cohort studies, in which cirrhotic patients without prior PVT treated with and without NSBBs are enrolled, and the development of PVT during follow-up is compared between the two groups. Additionally, subgroup analyses should be performed according to the dosage of NSBBs and the reduction of portal inflow velocity after use of NSBBs.

Deep vein thrombosis and pulmonary embolism in cirrhotic patients: Systematic review

Patients with liver cirrhosis were traditionally believed to be protected against development of blood clots. Lately, studies have shown that these patients may probably be at an increased risk of venous thrombotic complications. Although the hemostatic changes in the chronic liver disease patients and the factors that may predict bleeding vs thrombotic complications remains an area of active research, it is believed that the coagulation cascade is delicately balanced in these patients because of parallel reduced hepatic synthesis of pro and anticoagulant factors. Thrombotic state in cirrhotic patients is responsible for not only portal or non-portal thrombosis [deep vein thrombosis (DVT) and pulmonary embolism (PE)]; it has also been associated with progression of liver fibrosis. The use of anticoagulants in cirrhosis patients is a challenging, and often a scary situation. This review summarizes the current literature on the prevalence of venous thrombosis (DVT and PE), risk factors and safety of prophylactic and therapeutic anticoagulation in patients with chronic liver disease.

Increased thrombin generation in splanchnic vein thrombosis is related to the presence of liver cirrhosis and not to the thrombotic event

INTRODUCTION

In recent years there have been increasing evidence associating liver disease with hypercoagulability, rather than bleeding. The aim of the study was to evaluate the haemostatic potential in patients with liver disease.

PATIENTS AND METHODS

We measured thrombin generation in the presence and absence of thrombomodulin in patients with portal vein thrombosis (PVT, n=47), Budd-Chiari syndrome (BCS, n=15) and cirrhosis (n=24) and compared the results to those obtained from healthy controls (n=21). Fifteen patients with PVT and 10 patients with BCS were treated with warfarin and were compared to an equal number of patients with atrial fibrillation matched for prothrombin time-international normalized ratio. We assessed resistance to thrombomodulin by using ratios [marker measured in the presence/absence of thrombomodulin].

RESULTS

There were no differences in thrombin generation between patients on warfarin treatment and their controls. Cirrhotic patients generated more thrombin in the presence of thrombomodulin and exhibited thrombomodulin resistance compared to controls [p=0.006 for endogenous thrombin potential (ETP) and p<0.001 for peak thrombin and both ratios ETP and peak] and patients with non-cirrhotic PVT (p=0.001, p=0.006, p<0.001, p<0.001 for ETP, peak, ratio ETP, ratio peak, respectively). The patients with cirrhotic PVT exhibited higher ETP (p=0.044) and peak (p=0.02) in the presence of thrombomodulin than controls, as well as thrombomodulin resistance (ETP and peak ratios: p=0.001).

CONCLUSIONS

Hypercoagulability and thrombomodulin resistance in patients with cirrhosis were independent of the presence of splanchnic vein thrombosis. The hypercoagulability in patients with cirrhotic PVT could have implications for considering longer or more intensive treatment with anticoagulants in this group.

Risk factors and clinical characteristics of portal vein thrombosis after splenectomy in patients with liver cirrhosis

BACKGROUND

Portal vein thrombosis (PVT) is a potential lethal complication and may have negative influence on the prognosis after splenectomy in patients with liver cirrhosis. Prevention and timely detection of PVT are quite significant. There is a lack of knowledge about the clinical features and risk factors of PVT. Our study aimed to investigate the risk factors and clinical characteristics of PVT in order to figure out the high-risk individuals.

METHODS

We collected the clinical data of 472 consecutive patients with non-neoplastic liver cirrhosis who had undergone splenectomy from January 2008 to December 2010 in our institution. Clinical and surgical characteristics of patients who developed PVT postoperatively and those who did not develop PVT were compared. Univariate and multivariate analyses of risk factors of PVT were performed. The mortality and rebleeding rate of the patients were also evaluated.

RESULTS

Of the 472 patients, 52 were excluded from the study. PVT developed in 71 (71/420, 16.9%) patients. Multivariate analysis revealed that wider preoperative portal vein diameter, postoperative thrombocytosis, prolonged prothrombin time and periesophagogastric devascularization were significantly correlated with PVT development [odds ratio (OR): 5.701, 2.807, 1.850 and 2.090, respectively]. The incidence of PVT in patients who took antiplatelet drugs was not lower than that in those who did not. Follow-up showed that patients in the PVT group had a tendency towards reduced overall survival but it was not statistically significant. Gastrointestinal bleeding occurred more often in the PVT group than that in the non-PVT group (P=0.044).

CONCLUSIONS

Wider preoperative portal vein diameter, postoperative thrombocytosis, prolonged prothrombin time and periesophagogastric devascularization are independent risk factors of PVT. PVT is related with higher risk of postoperative gastrointestinal hemorrhage but has no significant impact on the overall survival.

Liver in haematological disorders

Prothrombotic haematological disorders, in particular myeloproliferative disorders, are identified in a significant proportion of patients with Budd-Chiari syndrome and portal vein thrombosis (PVT). Multiple prothrombotic disorders may coexist. PVT is diagnosed in one fourth of patients with cirrhosis and is more common with advanced liver disease and hepatocellular carcinoma. PVT in cirrhosis can precipitate decompensation. Intrahepatic microthrombosis may play a role in the pathogenesis of hepatic fibrosis. Sinusoidal obstruction syndrome is usually a complication of myeloablative treatment before haematopoietic stem cell transplantation. Post-transplant lymphoproliferative disorders can complicate liver transplantation and are related to Epstein-Barr virus infection. Hepatitis B reactivation in patients receiving chemotherapy for haematological malignancies is very common without pre-emptive treatment, and can lead to liver failure. Liver involvement is common in primary haematological diseases, such as haemolytic anaemias, lymphomas and leukaemia.

A dose-volume intercomparison of volumetric-modulated arc therapy, 3D static conformal, and rotational conformal techniques for portal vein tumor thrombus in hepatocellular carcinoma

We created volumetric-modulated arc therapy (VMAT) plans for portal vein tumor thrombus (PVTT) in hepatocellular carcinoma, and compared the results with those from three-dimensional conformal radiotherapy (3D-CRT) and rotational conformal radiotherapy (R-CRT) plans. CT scan data from 10 consecutive patients with PVTT treated with 3D-CRT between January 2008 and January 2010 were utilized in the analysis. We analyzed the dosimetric properties of the plans for the 10 patients using the three different techniques with three different isocenter doses of 50, 56 and 60 Gy in 2-Gy fractions. The D95, Dmean, homogeneity index and conformity index were compared for the planning target volume (PTV). The Dmean, V20 and V30 were also compared for normal livers. The monitor units (MUs) and the treatment time were also evaluated. The normal liver V30 for VMAT was significantly less than that for 3D-CRT for the prescribed doses of 56 and 60 Gy (P < 0.05). It was also found that the normal liver V30 resulting from 3D-CRT was prohibitively increased when the prescribed dose was increased in two steps. For PTV D95, we found no significant differences between the three techniques for the 50- and 56-Gy prescriptions, or between VMAT and the other techniques for the 60-Gy prescription. The differences in the MUs and treatment times were not statistically significant between VMAT and 3D-CRT. We have demonstrated that VMAT may be a more advantageous technique for dose escalation reaching 60 Gy in the treatment of PVTT due to the reduced normal liver V30.

Tissue factor pathway inhibitor and liver diseases

Tissue factor pathway inhibitor (TFPI) is a proteinase inhibitor that is synthesized by microvascular endothelial cells and can primarily exert anticoagulant and anti-inflammatory effects. In chronic liver disease and early liver cirrhosis, tissue factors are excessively expressed due to continuous stress, infections and inflammatory stimulation in liver microvascular endothelial cells, which may lead to the rise of TFPI concentration. In severe liver disease and liver cirrhosis complicated with portal vein thrombosis (PVT), the level of TFPI may decline for massive consumption. Recombinant TFPI (rTFPI) can effectively protect against PVT, reduce the mortality of disseminated or diffuse intravascular coagulation and improve inflammation. Understanding of the role of TFPI in liver diseases may provide potential strategy for the prevention and treatment of liver cirrhosis and its complications.