Portal vein thrombosis in Egyptian patients with liver cirrhosis: Role of methylenetetrahydrofolate reductase C677T gene mutation

The Molecular Mechanisms of Portal Vein Thrombosis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) represents the sixth most diagnosed cancer worldwide and is the second leading cause of cancer-related death in the world. The association of HCC and portal vein thrombosis (PVT) represents an advanced stage of the tumor. PVT has a prevalence of about 25-50% in HCC, determining poor prognosis and a remarkable reduction in therapeutic perspectives in these patients, leading to severe complications such as ascites, metastasis, an increase in portal hypertension and potentially fatal gastrointestinal bleeding. The aim of this review is to evaluate the molecular mechanisms that are at the basis of PVT development, trying to evaluate possible strategies in the early detection of patients at high risk of PVT.

Liver Cirrhosis Patients Homozygous for MTHFR C677T Develop Portal Vein Thrombosis 8 Years Earlier Than Wild Type

BACKGROUND AND AIM

Age at portal vein thrombosis (PVT) in liver cirrhosis (LC) carriers of the methylene tetrahydrofolate reductase (MTHFR) rs1801133 (C → T667 transition) polymorphism has never been addressed; we compared age at PVT in LC patients genotyped for the MTHFR and explored the interrelated clinical and laboratory factors predicting age at PVT.

APPROACH AND RESULTS

Retrospective cross-sectional cohort study. PVT participants: MTHFR CC n = 36, MTHFR CT n = 53, MTHFR TT n = 19; age, sex, age at PVT, Child-Pugh score, rs1799963 PT polymorphisms (G → A 20,210 transition), plasma HC and natural anticoagulants available for all participants. Age at PVT was lower in MTHFR TT than CT and CC (56 ± 13 vs. 57 ± 13 vs. 64 ± 9 years, p = 0.001); median (IQR) plasma HC was higher in MTHFR TT than in the other groups [(17 (9.4, 23.3) vs 13 (8,14.7) vs 11 (8.9, 12.7) μmol/l, p = 0.03)]. MTHFR TT, male gender and protein C predicted age at PVT (p = 0.02, p = 0.04 and p = 0.08); MTHFR TT and Child-Pugh score predicted plasma HC (p = 0.005 and p = 0.01) as well as low plasma protein C (p < 0.0001 and p = 0.0002). Plasma HC inversely related to protein C in the MTHFR TT group (p < 0.0001). Compound MTHFR TT with PT GA had lower age at PVT compared to MTHFR TT alone (49 ± 18 vs 58 ± 12 years).

CONCLUSIONS

MTHFR TT anticipates PVT associated with LC by an average of 8 years; MTHFR TT associates with severity of liver disease and to high plasma HC; the latter may contribute to the prematurity of PVT by interfering with the anticoagulant activity of protein C.

Portal Vein Thrombosis in the Setting of Cirrhosis: A Comprehensive Review

Portal vein thrombosis constitutes the most common thrombotic event in patients with cirrhosis, with increased rates in the setting of advanced liver disease. Despite being a well-known complication of cirrhosis, the contribution of portal vein thrombosis to hepatic decompensation and overall mortality is still a matter of debate. The incorporation of direct oral anticoagulants and new radiological techniques for portal vein recanalization have expanded our therapeutic arsenal. However, the lack of large prospective observational studies and randomized trials explain the heterogenous diagnostic and therapeutic recommendations of current guidelines. This article seeks to make a comprehensive review of the pathophysiology, clinical features, diagnosis, and treatment of portal vein thrombosis in patients with cirrhosis.

Epidemiology of portal vein thrombosis in liver cirrhosis: A systematic review and meta-analysis

BACKGROUND

Portal vein thrombosis (PVT) may be associated with negative outcomes in patients with liver cirrhosis. However, the prevalence and incidence of PVT in liver cirrhosis are heterogeneous among studies and have not been sufficiently determined yet.

METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched. Eligible studies would explore the prevalence and/or incidence of PVT in liver cirrhosis without hepatocellular carcinoma or abdominal surgery. Pooled proportion with 95% confidence interval (CI) was calculated using a random-effect model. Factors associated with the presence/occurrence of PVT were also extracted.

RESULTS

Among the 8549 papers initially identified, 74 were included. Fifty-four studies explored the prevalence of PVT in liver cirrhosis with a pooled prevalence of 13.92% (95%CI=11.18-16.91%). Based on cross-sectional data, Child-Pugh class B/C, higher D-dimer, ascites, and use of non-selective beta-blockers (NSBBs) were associated with the presence of PVT in liver cirrhosis. Twenty-three studies explored the incidence of PVT in liver cirrhosis with a pooled incidence of 10.42% (95%CI=8.16-12.92%). Based on cohort data, Child-Pugh class B/C, higher model of end-stage liver disease score, higher D-dimer, lower platelets count, decreased portal flow velocity, ascites, use of NSBBs, and moderate or high-risk esophageal varices could predict the occurrence of PVT in liver cirrhosis.

CONCLUSION

Approximately one seventh of cirrhotic patients have PVT, and one tenth will develop PVT. Progression of liver cirrhosis and portal hypertension seems to be in parallel with the risk of PVT. Prospective studies with detailed information about classification and extension of PVT in liver cirrhosis are needed.

Portal Thrombosis in Cirrhosis: Role of Thrombophilic Disorders

In patients with liver cirrhosis the contribution of inherited and acquired prothrombotic disorders in the development of non-malignant portal vein thrombosis (PVT) is inconclusive. The purpose of this retrospective study was to examine the prevalence of thrombophilia in this setting at our center from January 2012 to November 2019. Tests included gene mutational analysis for Factor V Leiden, prothrombin G20210A, JAK2 (V617F), Calreticulin (CARL), in addition to activated protein C resistance, antithrombin III, protein C and S levels, and antiphospholipid antibodies. We included 77 patients, six of whom (7.8%) had a thrombophilic disorder: antiphospholipid syndrome in four patients, prothrombin gene mutation in one and factor V Leiden mutation in one. This latter patient had also been diagnosed with polycythemia vera years before PVT development. Complete thrombosis of the main portal vein and re-thrombosis after stopping anticoagulation were more frequent in patients with thrombophilia, but the rates of recanalization under anticoagulant therapy were similar among groups. No other difference was accounted between groups. The low prevalence of acquired and inherited thrombophilia found in patients with cirrhosis and PVT support testing for these disorders on an individual basis and avoiding universal screening to reduce costs and unwarranted testing.

Review of Serum Biomarkers and Models Derived from Them in HBV-Related Liver Diseases

A series of predictive scoring systems is available for stratifying the severity of conditions and assessing the prognosis in patients with HBV-related liver diseases. We show nine of the most popular serum biomarkers and their models (i.e., serum cystatin C, homocysteine, C-reactive protein, C-reactive protein to albumin ratio, aspartate aminotransferase to platelet ratio index, fibrosis index based on four factors, gamma-glutamyl transpeptidase to platelet ratio, albumin-bilirubin score, and gamma-glutamyl transpeptidase to albumin ratio) that have gained great interest from clinicians. Compared with traditional scoring systems, these serum biomarkers and their models are easily acquired, simple, and relatively inexpensive. In the present review, we summarize the latest studies focused on these serum biomarkers and their models as diagnostic and prognostic indexes in HBV-related liver diseases.

A Preclinical Porcine Model of Portal Vein Thrombosis in Liver Cirrhosis

Background

This study aimed at presenting a novel method of developing a porcine model of portal vein thrombosis (PVT) in cirrhosis by intravenous administration of thrombin and insertion of a fibered coil. We further investigated changes of biochemical parameters, coagulation, and proinflammatory cytokine expression in the cirrhosis-PVT group.

Methods

Twelve male pigs were randomized into the control group (n = 3) and cirrhosis group (n = 9). In cirrhotic pigs, three were randomly selected to establish PVT by ultrasound-guided percutaneous puncture of the main portal vein (MPV) followed by intravenous thrombin administration and fibered coil insertion. Thrombosis in the MPV was detected by abdominal enhanced computer tomography (CT). The changes of hepatic function, coagulation system, and inflammation cytokines were compared among normal, cirrhosis, and cirrhosis with PVT groups.

Results

As manifested by the presence of a filling defect in MPV on portal venous-phase CT angiography, fibrin thrombi were formed in the MPV in cirrhotic pigs within one week and persisted for four weeks. Five weeks after surgery, abnormal liver functions occurred in association with PVT formation in cirrhosis. Both coagulation and thromboelastography parameters showed that cirrhosis-PVT pigs exhibited a procoagulant state through hyperfunction of platelets and clotting factors. Interleukin 6 (IL-6) as a potential inflammatory marker stimulated PVT-mediated inflammation activation in cirrhosis.

Conclusions

Our study provides in vivo evidence that intravenous injection of a coil and thrombin into MPV under interventional guided devices enables a feasible method in thrombus creation. Further exploration and validation of large-sample cases are required to characterize utilities of this model.

Hyperhomocysteinemia is associated with severity of cirrhosis and negative impact after liver transplantation

BACKGROUND & AIMS

Hyperhomocysteinemia constitutes an independent risk factor for thrombosis and cellular injury promoted by oxidative stress. The clinical significance of hyperhomocysteinemia in cirrhosis and outcomes post-liver transplantation is poorly documented. In this study, we aimed to determine the prevalence of hyperhomocysteinemia in cirrhosis, evaluate its association with thrombosis and severity of liver disease, and its impact on survival after liver transplantation.

METHODS

We analysed 450 patients with cirrhosis who received a liver transplant between 2001 and 2010. Data were recovered from medical charts and homocysteine serum levels were determined before liver transplantation in all patients.

RESULTS

Median age was 53 years (range, 18-72 years) and 308 patients were males (68%). Cirrhosis aetiology was hepatitis C (37%), autoimmune liver disease (22%), alcohol (16%) and others (25%). The median homocysteine level was 11 μmol/L (range, 4-221 μmol/L) and 165 patients (37%) had hyperhomocysteinemia. The MELD (23 ± 10 vs. 20 ± 9 points, P < 0.001), and Child-Pugh (11 ± 2 vs. 9 ± 2 points, P < 0.001) scores were higher in patients with hyperhomocysteinemia. Episodes of thrombosis occurred in 91 patients (20%), but there was no significant difference in patients with or without hyperhomocysteinemia (19 vs. 21%, P = 0.6). Hyperhomocysteinemia was associated with reduced graft (105 ± 4 vs. 119 ± 2 months; P = 0.005), and patient survival (125 ± 33 vs. 131 ± 2 months; P = 0.006).

CONCLUSIONS

Hyperhomocysteinemia is frequently present in patients with cirrhosis and is associated with severe liver disease and reduced graft and patient survival after liver transplantation. The negative impact hyperhomocysteinemia has on graft and patient survival is not related to thrombosis.

Role of Hyperhomocysteinemia and Methylene Tetrahydrofolate Reductase C677T Polymorphism in Idiopathic Portal Vein Thrombosis

Purpose:

Portal vein thrombosis (PVT) is a rare and life-threatening vascular disorder characterized by obstruction or narrowing of the portal vein. Hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism has been studied in PVT patients with conflicting results. In the present study the association of hyperhomocysteinemia and MTHFR C677T polymorphism with PVT risk was investigated in Iranians.

Materials and Methods:

Our study population consisted of 10 idiopathic PVT patients and 80 healthy control subjects matched for age and sex. MTHFR C677T polymorphism was genotyped by the polymerase chain reaction technique combined with restriction enzyme fragment length polymorphism (PCR-RFLP) technique and plasma total homocysteine (tHcy) levels were determined by enzyme immunoassay method.

Results:

Mean plasma tHcy levels were significantly higher in PVT patients (20.2±6.8) than control subjects (10.9±4.7) (P=0.001). Moreover, plasma tHcy levels were significantly higher in 677T allele carriers relative to 677C allele carriers in both PVT patients (P=0.01) and control subjects (P=0.03). Neither homozygote nor heterozygote genotypes of MTHFR C677T polymorphism correlated significantly with PVT risk (P>0.05). Moreover, MTHFR C677T polymorphism didn’t increase the risk of PVT under dominant (CT+TT vs. CC) or recessive (TT vs. CC+CT) genetic models analyzed (P>0.05). The difference in frequency of minor 677T allele between PVT patients and control subjects was not statistically significant (P>0.05).

Conclusion:

Based on the current study, we suggest that hyperhomocysteinemia constitutes a significant and common risk factor for PVT. Also, MTHFR C677T polymorphism is not a risk factor for PVT but is a contributing factor for elevated plasma tHcy levels.

Nontumoral portal vein thrombosis in patients awaiting liver transplantation

Portal vein thrombosis (PVT) occurs in approximately 2%-26% of the patients awaiting liver transplantation (LT) and is no longer an absolute contraindication for LT. Nearly half of PVT cases are accidentally found during the LT procedure. The most important risk factor for PVT development in cirrhosis may be the severity of liver disease and reduced portal blood flow. Whether other inherited or acquired coagulation disorders also play a role is not yet clear. The development of PVT may have no effect on the liver disease progression, especially when it is nonocclusive. PVT may not increase the risk of wait-list mortality, but it is a risk factor for poor early post-LT mortality. Anticoagulation and transjugular intrahepatic portosystemic shunt (TIPS) are 2 major treatment strategies for patients with PVT on the waiting list. The complete recanalization rate after anticoagulation is approximately 40%. The role of TIPS to maintain PV patency for LT as the primary indication has been reported, but the safety and efficacy should be further evaluated. PVT extension and degree may determine the surgical technique to be used during LT. If a "conventional" end-to-end portal anastomotic technique is used, there is not a major impact on post-LT survival. Post-LT PVT can significantly reduce both graft and patient survival after LT and can preclude future options for re-LT.

Novel insights into the development of portal vein thrombosis in cirrhosis patients

The prognostic impact of portal vein thrombosis (PVT) in liver cirrhosis remains controversial among studies, primarily because the risk stratification of PVT is often lacking. A definition of clinically significant PVT should be proposed and actively improved. Moreover, the risk factors for the development of PVT in liver cirrhosis should be fully recognized to screen and identify high-risk patients. Currently, well-recognized risk factors include a reduced portal vein flow velocity, a worse liver function, splenectomy, liver transplantation, and factor V Leiden and prothrombin G20210A mutations. Novel risk factors include an increased flow volume of portosystemic collateral vessel, thrombopoietin receptor agnonists, and non-selective beta-blockers. In contrast to the traditional perspectives, the abnormalities of procoagulant and anticoagulant factors may not contribute to the development of PVT in liver cirrhosis. Further studies should explore the role of other risk factors, such as antiphospholipid antibodies, methylenetetrahydrofolate reductase C677T gene mutation, hyperhomocysteinemia, and myeloproliferative neoplasms.

Thrombosis and hemorrhage in the critically ill cirrhotic patients: five years retrospective prevalence study

BACKGROUND

Cirrhotic patients present a complex interaction between deficient synthetic liver function, hemodynamic abnormalities and superimposed conditions that alter coagulation system. This alters both coagulation and fibrinolytic processes,increasing bleeding and thrombosis risks. Particularly, critically ill cirrhotic patients represent a diagnostic challenge since they have multiple comorbidities making the thrombotic and bleeding risks unpredictable. The prevalence of bleeding and thrombosis in this subset of patients remains poorly described. The main aim of this article is to describe the prevalence of thrombotic and hemorrhagic complications in cirrhotic patients admitted between 2007 and 2012 at Médica Sur Clinic and Foundation ICU.

MATERIAL AND METHODS

We performed a five years retrospective study including every cirrhotic patient admitted to ICU between January 2007 and December 2012.

RESULTS

The incidence of hemorrhage was 48.5%, the overall incidence of thrombotic complications was 13.66%. Variceal bleeding was the most prevalent hemorrhagic event and portal vein thrombosis the most common thrombotic event. Factors associated with presenting a bleeding episode included kidney injury, infection an thrombosis. Factors associated with increased thrombotic risk included ascitis,infection and bleeding.

CONCLUSION

Critically ill cirrhotic patients have an high risk for both thrombotic and bleeding episodes. The association between the presence of bleeding and thrombotic events was statistically significant.

Methylenetetrahydrofolate reductase C677T gene mutation and hyperhomocysteinemia in Budd-Chiari syndrome and portal vein thrombosis: A systematic review and meta-analysis of observational studies

AIM

A systematic review and meta-analysis were conducted to explore the role of the methylenetetrahydrofolate reductase (MTHFR) C677T gene mutation and hyperhomocysteinemia in patients with Budd-Chiari syndrome (BCS) and portal vein thrombosis (PVT).

METHODS

PubMed, EMBASE, Cochrane Library and ScienceDirect databases were searched. Eligible studies should compare the prevalence of the MTHFR C677T mutation or hyperhomocysteinemia or the homocysteine levels between BCS or non-cirrhotic PVT patients and healthy controls or between cirrhotic patients with and without PVT. A pooled odds ratio or weighted mean difference with 95% confidence interval was calculated.

RESULTS

Of the 484 articles retrieved, 20 were included. BCS and non-cirrhotic PVT patients had a higher prevalence of homozygous MTHFR mutation than healthy controls. The difference was statistically significant in BCS patients, but not in non-cirrhotic PVT patients. BCS and non-cirrhotic PVT patients had a significantly higher prevalence of hyperhomocysteinemia and homocysteine level than healthy controls. Cirrhotic patients with PVT had a significantly higher prevalence of homozygous MTHFR mutation than those without PVT. However, the association between homocysteine level and PVT in cirrhotic patients was inconsistent among three studies.

CONCLUSION

Homozygous MTHFR mutation and hyperhomocysteinemia may be associated with the occurrence of BCS and non-cirrhotic PVT. In addition, homozygous MTHFR mutation may increase the risk of PVT in cirrhotic patients. However, the current evidence failed to support the association of hyperhomocysteinemia with PVT in cirrhotic patients.

Management of portal vein thrombosis in liver cirrhosis

Portal vein thrombosis (PVT) is a fairly common complication of liver cirrhosis. Importantly, occlusive PVT might influence the prognosis of patients with cirrhosis. Evidence from a randomized controlled trial has shown that anticoagulation can prevent the occurrence of PVT in patients with cirrhosis without prior PVT. Evidence from several case series has also demonstrated that anticoagulation can achieve portal vein recanalization in patients with cirrhosis and PVT. Early initiation of anticoagulation therapy and absence of previous portal hypertensive bleeding might be positively associated with a high rate of portal vein recanalization after anticoagulation. However, the possibility of spontaneous resolution of partial PVT questions the necessity of anticoagulation for the treatment of partial PVT. In addition, a relatively low recanalization rate of complete PVT after anticoagulation therapy suggests its limited usefulness in patients with complete PVT. Successful insertion of a transjugular intrahepatic portosystemic shunt (TIPS) not only recanalizes the thrombosed portal vein, but also relieves the symptomatic portal hypertension. However, the technical difficulty of TIPS potentially limits its widespread application, and the risk and benefits should be fully balanced. Notably, current recommendations regarding the management of PVT in liver cirrhosis are insufficient owing to low-quality evidence.

Portal vein thrombosis in liver cirrhosis

Portal vein thrombosis (PVT) is considered to be a frequent complication of liver cirrhosis. However, unlike PVT in patients without cirrhosis, very few data are available on the natural history and management of PVT in cirrhosis, despite its association with potentially life-threatening conditions, such as gastroesophageal bleeding and acute intestinal ischemia. Moreover, no consensus regarding PVT in cirrhosis exists. Suggested causes of PVT in cirrhosis include reduced portal blood flow velocity, multiple congenital or acquired thrombophilic factors, inherited or acquired conditions, and derangement of liver architecture. However, the understanding of PVT in cirrhosis is incomplete. In addition, information on the management of PVT in cirrhosis is inadequate. The aims of this review are to: (1) assemble data on the physiopathological mechanism, clinical findings, diagnosis and management of PVT in cirrhosis; (2) describe the principal factors most frequently involved in PVT development; and (3) summarize the recent knowledge concerning diagnostic and therapeutic procedures.

Coagulation abnormalities in the cirrhotic patient

The clotting process is a dynamic array of multiple processes which can be described in four phases: platelet plug initiation and formation, clotting process propagation by the coagulation cascade, clotting termination by antithrombotic mechanisms and clot removal by fibrinolysis. The liver plays a central role in each of these phases of clotting process, as it synthesizes the majority of coagulation factors and proteins involved in fibrinolysis as well as thrombopoeitin, which is responsible for platelet production from megakaryocytes. Many pathological processes associated with cirrhosis, such as portal hypertension and endothelial dysfunction, as well as co-morbid conditions, may also alter the coagulation process. Consequently, patients with liver disease have a disturbed balance of procoagulant and anti-coagulant factors which deviates from the normal coagulation cascade. This situation poses an additional problem in the diagnostic and therapeutic approach to this group of patients, since traditional coagulation test may not be reliable for assessing bleeding or thrombotic risk and traditional transfusional strategies may not be applicable in cirrhotic patients. In this article, we review the pathophysiological bases of coagulation abnormalities, in cirrhotic patients, the diagnostic therapeutic strategies to be followed and its impact on the clinical outcome in the cirrhotic patient.

Effect of antithrombin, protein C and protein S on portal vein thrombosis in liver cirrhosis: a meta-analysis

BACKGROUND

The effects of antithrombin (AT), protein C (PC) and protein S (PS) on the pathogenesis of portal vein thrombosis (PVT) in liver cirrhosis remain controversial in different studies. In this study, a systematic review and meta-analysis to examine this issue were performed.

METHODS

PubMed database was employed to identify all studies in which AT, PC and PS concentrations were measured in both cirrhotic patients with and without PVT. A standardized mean difference (SMD) with 95% confidence interval (CI) was calculated to evaluate the effect of AT, PC and PS on PVT. Data were pooled using both fixed-effect and random-effect models. Only the pooled data using random-effect model were considered appropriate, when significant heterogeneity was observed.

RESULTS

Nine studies involving 160 cirrhotic patients with PVT and 428 cirrhotic patients without PVT were eligible. AT and PC concentrations were similar between PVT and non-PVT groups (AT: SMD = -0.21, 95% CI = -0.56 to 0.14, P = 0.24; PC: SMD = -0.23, 95% CI = -0.55 to 0.09, P = 0.16). But PS concentration was significantly lower in the PVT group than in the non-PVT group (SMD = -0.29, 95% CI = -0.49 to -0.08, P = 0.006). Subgroup analyses were further conducted in 4 studies in which baseline liver function was similar between cirrhotic patients with and without PVT, showing similar AT, PC and PS concentrations between the 2 groups (AT: SMD = -0.10, 95% CI = -0.36 to 0.16, P = 0.57; PC: SMD = -0.18, 95% CI = -0.62 to 0.25, P = 0.41; PS: SMD = -0.10, 95% CI = -0.59 to 0.39, P = 0.69).

CONCLUSIONS

AT, PC and PS concentrations might not be associated with the pathogenesis of PVT in liver cirrhosis, especially when the impact of liver function was excluded.

Value of D-dimer and protein S for diagnosis of portal vein thrombosis in patients with liver cirrhosis

OBJECTIVE

To investigate the value of D-dimer and protein S plasma concentrations for diagnosis of portal vein thrombosis (PVT) in patients with liver cirrhosis.

METHODS

D-dimer and protein S were quantified, PVT was diagnosed by dynamic enhanced computed tomography and liver function was classified using the Child-Pugh system. Receiver operating curve analysis was performed.

RESULTS

D-dimer increased, and protein S decreased, with decreasing liver function in the total study population (n = 188). D-dimer concentrations were significantly higher and protein S concentrations were significantly lower in patients with (n = 51) than those without PVT (n = 137). D-dimer had high specificity and negative predictive value (NPV) in Child-Pugh class A or B patients (cut-off values>0.56 mg/l and >1.18 mg/l, respectively). In class C patients>0.77 mg/l D-dimer had high sensitivity and NPV. Protein S had high sensitivity but low specificity in class A or B patients (cut-off values < 17.4 mg/l and <19.2 mg/l, respectively).

CONCLUSION

Plasma D-dimer and protein S are potential biomarkers for PVT diagnosis in patients with cirrhosis. PVT can be excluded when D-dimer is low and protein S is elevated.

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

Portal vein thrombosis (PVT) is one of the most common complications occurring during the natural course of liver cirrhosis. Even though PVT is often asymptomatic, the worsening of liver function, an unexpected episode of gastrointestinal bleeding or ascitic decompensation may be landmarks of PVT development. Beyond these clinical manifestations, it is debated whether PVT really has an impact on liver cirrhosis natural history or rather represents only one of its consequences. Probably PVT development should not only be considered as a matter of impaired blood flow or pro-coagulation tendency. On one hand, PVT seems a consequence of the worsening in portal vein outflow due to the increased hepatic resistance in cirrhotic livers. On the other hand, vascular microthrombosis secondary to necroinflammation may cause liver ischemia and infarction, with loss of hepatic tissue (parenchymal extinction) which is replaced by fibrotic tissue. Therefore, PVT might also be considered as the overt manifestation of the liver fibrosing process evolution and anticoagulant therapy may thus have microscopic indirect effects also on the progression of liver disease. At present, a connection between PVT development and the progression of liver fibrosis/cirrhosis has not yet been demonstrated. Nevertheless, it is not clear if PVT development may worsen cirrhotic patients' outcome by itself. Some authors tried to assess liver transplant benefit in PVT cirrhotic patients but data are contrasting. In this review, we will try to answer these questions, providing a critical analysis of data reported in literature.