Thrombophilic factor analysis in cirrhotic patients with portal vein thrombosis

Incident portal vein thrombosis in liver transplant recipients in New Zealand: Predictors of risk and validation of portal vein thrombosis risk index calculator

The risk of spontaneous portal vein thrombosis (PVT) is increased in patients on the waiting list for liver transplantation and increases perioperative risks. A predictive PVT risk-index (PVT-RI) calculator has been proposed to determine the risk of incident PVT. We performed a retrospective analysis on adult liver transplant recipients at the NZ Liver Transplant Unit between January 1998 and February 2020. Variables reviewed included age at listing and transplantation, wait time from listing to transplant, indication for listing, gender, ethnicity, etiology of liver disease, listing MELD score, hepatocellular carcinoma (HCC), moderate-to-severe ascites, hepatic encephalopathy (>grade 2), transjugular intrahepatic portosystemic shunt (TIPSS), spontaneous bacterial peritonitis (SBP), and diabetes. Incident PVT was determined by imaging of patients while on the waiting list and assessment at transplantation. A total of 553 out of 706 patients met the inclusion criteria. Of those 553, 18 (3.3%) patients had incident PVT. The PVT-RI calculator was not validated in our cohort with only one of those 18 (6%) patients having a score of >4.6 (high risk cut-off score). Longer waiting time for transplant and listing for liver failure rather than HCC were independent predictors of the risk of incident PVT. There was no statistically significant difference in the incidence of PVT in viral vs. non-viral and cholestatic vs. non-cholestatic etiology of chronic liver disease. Patients with longer waiting times on the transplant waiting list should be monitored regularly for PVT.

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.

Nonmalignant portal vein thrombi in patients with cirrhosis consist of intimal fibrosis with or without a fibrin-rich thrombus

BACKGROUND AND AIM

Portal vein thrombosis (PVT) is a common complication of cirrhosis. The exact pathophysiology remains largely unknown, and treatment with anticoagulants does not lead to recanalization of the portal vein in all patients. A better insight into the structure and composition of portal vein thrombi may assist in developing strategies for the prevention and treatment of PVT.

APPROACH AND RESULTS

Sixteen prospectively and 63 retrospectively collected nonmalignant portal vein thrombi from patients with cirrhosis who underwent liver transplantation were included. Histology, immunohistochemistry, and scanning electron microscopy were used to assess structure and composition of the thrombi. Most recent CT scans were reanalyzed for thrombus characteristics. Clinical characteristics were related to histological and radiological findings. All samples showed a thickened, fibrotic tunica intima. Fibrin-rich thrombi were present on top of the fibrotic intima in 9/16 prospective cases and in 21/63 retrospective cases. A minority of the fibrotic areas stained focally positive for fibrin/fibrinogen (16% of cases), von Willebrand factor (VWF; 10%), and CD61 (platelets, 21%), while most of the fibrin-rich areas stained positive for those markers (fibrin/fibrinogen, 100%; VWF, 77%; CD61, 100%). No associations were found between clinical characteristics including estimated thrombus age and use of anticoagulants and presence of fibrin-rich thrombi.

CONCLUSION

We demonstrate that PVT in patients with cirrhosis consists of intimal fibrosis with an additional fibrin-rich thrombus in only one-third of cases. We hypothesize that our observations may explain why not all portal vein thrombi in patients with cirrhosis recanalize by anticoagulant therapy.

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.

Current knowledge and management of portal vein thrombosis in cirrhosis

Portal vein thrombosis (PVT) is an increasingly recognised complication of cirrhosis whose incidence increases in parallel with the severity of cirrhosis. Several risk factors have been associated with the occurrence and progression of PVT. Although the negative effect of complete PVT on the surgical outcome of liver transplant recipients is clear, its impact on cirrhosis progression remains uncertain. Treatment options include anticoagulants and interventional thrombolytic therapies, which are chosen almost on a case-by-case basis depending on the characteristics of the patient and the thrombus. In this manuscript, we review current knowledge regarding the epidemiology, risk factors, diagnosis and classification, natural history, clinical consequences and treatment of non-neoplastic PVT in cirrhosis.

Nontumoral Portal Vein Thrombosis: A Challenging Consequence of Liver Cirrhosis

Nontumoral portal vein thrombosis (PVT) is an increasingly recognized complication in patients with cirrhosis. Substantial evidence shows that portal flow stasis, complex thrombophilic disorders, and exogenous factors leading to endothelial dysfunction have emerged as key factors in the pathogenesis of PVT. The contribution of PVT to hepatic decompensation and mortality in cirrhosis is debatable; however, the presence of an advanced PVT increases operative complexity and decreases survival after transplantation. The therapeutic decision for PVT is often determined by the duration and extent of thrombosis, the presence of symptoms, and liver transplant eligibility. Evidence from several cohorts has demonstrated that anticoagulation treatment with vitamin K antagonist or low molecular weight heparin can achieve recanalization of the portal vein, which is associated with a reduction in portal hypertension-related events and improved survival in cirrhotic patients with PVT. Consequently, interest in direct oral anticoagulants for PVT is increasing, but clinical data in cirrhosis are limited. Although the most feared consequence of anticoagulation is bleeding, most studies indicate that anticoagulation therapy for PVT in cirrhosis appears relatively safe. Interestingly, the data showed that transjugular intrahepatic portosystemic shunt represents an effective adjunctive therapy for PVT in cirrhotic patients with symptomatic portal hypertension if anticoagulation is ineffective. Insufficient evidence regarding the optimal timing, modality, and duration of therapy makes nontumoral PVT a challenging consequence of cirrhosis. In this review, we summarize the current literature and provide a potential algorithm for the management of PVT in patients with cirrhosis.

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.

New Insights into the Pathogenesis, Risk Factors, and Treatment of Portal Vein Thrombosis in Patients with Cirrhosis

Portal vein thrombosis (PVT) is a frequent event in patients with cirrhosis regardless of etiology. Notwithstanding the commonality of the problem, the pathophysiology and risk factors for PVT in cirrhosis are largely unknown. The clinical impact of PVT in the natural history of cirrhosis is unclear, indications for PVT treatment are not well defined, and treatment recommendations are based on experts' opinion and consensus only. Therefore, this review aims to summarize current knowledge of mechanisms and risk factors for PVT development and assess the current evidence of PVT management, with a special focus on strategies of anticoagulation and transjugular intrahepatic portosystemic shunt placement.

Liver Disease and Hemostasis (Review) Part 2. Cholestatic Liver Disease and Hemostasis

The presence or development of liver disorders can significantly complicate the course of critical illness and terminal conditions. Systemic hemostatic disorders are common in Intensive Care Units patients with cholestatic liver diseases, so the study of the mechanisms of their development can contribute to the understanding of the development of multiorgan failure in critical illness.

The review discusses current data on changes in hemostatic parameters in patients with cholestatic liver diseases, proposes a mechanism for the development of such disorders, which involve interactions of phospholipids with platelet and endotheliocyte membranes. It is suggested that a trend for thrombosis in patients with cholestatic liver disease is due to increased accumulation of bile acids in the systemic circulation. Available data demonstrate that the antiphospholipid syndrome may predispose to the formation of blood clots due to alterations of phospholipid composition of membranes of platelets and vascular endothelial cells by circulating antiphospholipid antibodies. Clarifying the mechanisms contributing to changes of the blood coagulation system parameters in liver disorders will aid to development of optimal correction of hemostatic disorders in patients with chronic liver diseases.

Thrombophilia in hepatocellular carcinoma

Background

Chronic liver disease and hepatocellular carcinoma (HCC) can cause a disturbance in the coagulation system. In this study, we aimed to assess the risk factors for venous thromboembolism either acquired or hereditary in patients with HCC.

Results

Serum levels of proteins C and S, AT activity, and lipoprotein (a) were significantly lower in both HCC and cirrhotic patients while homocysteine levels were significantly higher in HCC patients. The prevalence of activated protein C resistance (APCR) and factor V Leiden (FVL) mutation was higher in HCC patients but with no significant differences between the studied groups. With multivariate analysis, prothrombin time, Fbg, protein C and S deficiency, increased lipoprotein (a), hyperhomocysteinemia, APCR, and FVL mutation were independent risk factors for thromboembolic complications in HCC patients.

Conclusions

Thrombophilic abnormalities are prevalent in HCC patients, and they have a substantial increased risk of venous thromboembolism.

Development of a Model to Predict Portal Vein Thrombosis in Liver Transplant Candidates: The Portal Vein Thrombosis Risk Index

Portal vein thrombosis (PVT) is associated with inferior pretransplantation and posttransplantation outcomes. We aimed to create a predictive model to risk stratify transplant candidates for PVT. Data on adult transplants in the United States during the Model for End-Stage Liver Disease (MELD) era through September 2016 were reviewed. We constructed and validated a scoring system composed of routine, readily available clinical information to predict the development of incident PVT at 12 months from transplantation listing. A total of 66,568 liver transplant candidates were dichotomized into 2 groups to construct (n = 34,751) and validate (n = 31,817) a scoring system. In general, the derivation and validation cohorts were clinically similar. Although nonalcoholic steatohepatitis was a significant predictor of incident PVT (hazard ratio, 1.29; 95% confidence interval, 1.08-1.54; P < 0.001), age, MELD score, and moderate-to-severe ascites were also associated with increased risk. African American race was associated with decreased risk. A scoring system (PVT risk index [RI]) of these 5 variables had an area under the curve of 0.71 and 0.70 in both derivation and validation cohorts, respectively. By applying the low cutoff score of 2.6, incident PVT could be accurately excluded (negative predictive value 94%). Using the high cutoff score of 4.6 (positive predictive value 85%), PVT could be diagnosed with high accuracy. The PVT-RI predicts which candidates awaiting lifesaving liver transplantation will and will not develop future PVT. Although this scoring system will require prospective validation, it provides a powerful new tool for the clinician when risk stratifying cirrhosis patients prior to liver transplantation for future PVT development.

Inherited thrombophilia and portal vein thrombosis in cirrhosis: A systematic review and meta-analysis

BACKGROUND

Portal vein thrombosis (PVT) is common in cirrhosis. PVT is associated with high morbidity and mortality. Individual reports suggest that PVT occurs more frequently in patients with cirrhosis and inherited thrombophilia. The relationship between cirrhosis, PVT development, and inherited thrombophilia was explored in this study. The aim of the study was to determine whether cirrhotic patients with nontumoral PVT have an increased rate of inherited thrombophilia.

METHODS

Studies were identified by searching electronic databases up to October 2017 with English language and human subject restrictions. Two independent reviewers screened citations and extracted data. Magnitude of effect was calculated to obtain aggregate estimates of effect size and 95% confidence intervals (CIs). Between-study variability and heterogeneity were assessed.

RESULTS

Of 2893 citations identified, 9 studies composed of 1929 subjects with cirrhosis were included. The overall prevalence of PVT was 6.5% (n = 125). Both prothrombin G20210A mutation (odds ratio [OR], 2.43; 95% CI, 1.07-5.53; P = 0.03) and factor V Leiden (FVL) (OR, 1.98; 95% CI, 1.06-3.68; P = 0.03) were significantly associated with PVT risk. Methyltetrahydrofolate reductase C677T mutation was not associated with increased PVT risk. No heterogeneity or publication bias was observed. One important study with opposite findings could not be included due to lack of primary data.

CONCLUSIONS

FVL and PTG20210A mutation were associated with increased PVT risk in patients with cirrhosis. This finding reframes the role of inherited thrombophilia in PVT development in patients with cirrhosis. Future prospective studies investigating screening for inherited thrombophilia in all cirrhosis patients with PVT seem warranted.

A Review on Clinical, Pathophysiological, and Diagnostic Hematological Features in Children With Liver Cirrhosis

Appropriate diagnostic and therapeutic measures for liver cirrhosis is critical, particularly in children. In the present review, a comprehensive approach was provided toward hematological parameters in pediatric liver cirrhosis. The literature search included MeSH terms "liver cirrhosis" and "hepatic cirrhosis" and databases such as PubMed, Web of Science, Scopus, and Google Scholar were searched up until December 2017. Hematologic changes in the liver cirrhosis mainly encompassed anemia and coagulopathies. In addition, bleeding diathesis was considered as the most clinical complication in these patients. In addition to reduced coagulation factors, hyperfibrinolysis is a common feature in childhood cirrhosis and may be an important contributor to the risk of bleeding. Based on the results, children with liver cirrhosis also demonstrated a procoagulant state at laboratory and clinical levels. This may be partly due to a reduction in coagulation inhibitors such as anti-thrombin, C1 inhibitor, and α1-antitrypsin in children with cirrhosis. The portal vein thrombosis and portal hypertension are considered as the most clinical presentations of the hypercoagulable state. Further, children with liver cirrhosis complicated with portal hypertension usually show leukopenia, anemia, and thrombocytopenia due to hypersplenism. Although the etiology of childhood and adult cirrhosis may be different, their hematological compilations and clinicopathological features are somehow similar.

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.

Anticoagulation in the cirrhotic patient

In the past, patients with liver cirrhosis were thought to be prone to increased bleeding risk. However, those with compensated liver cirrhosis actually have normal coagulative balance, which can become altered when liver function worsens, or infection, bleeding, or acute kidney insufficiency occur. When this happens, it is now recognized that patients with liver cirrhosis are at higher risk of thrombotic rather than haemorrhagic complications. Anticoagulation plays a favourable role both when used therapeutically or prophylactically. Successful anticoagulation is associated with a lower rate of decompensation and with improved survival. To date, treatment has involved the use of low molecular weight heparins and vitamin K antagonists. Preliminary data suggest that novel non-vitamin K antagonist oral anticoagulants can be used safely in patients with liver cirrhosis.

Management of Non-tumoral Portal Vein Thrombosis in Patients with Cirrhosis

Non-tumoral portal vein thrombosis (PVT) remains a highly relevant topic in the field of hepatology and liver transplantation with much surrounding controversy. Although multiple studies have shown that PVT is associated with adverse outcomes with increased morbidity and mortality rates, others have not reported the same clinical impact of PVT, arguing rather that incident PVT reflects worsening portal hypertension and the natural history of the disease. Despite this uncertainly, PVT is a dilemma facing the clinician on a daily basis often requiring a multidisciplinary team-based approach between hepatologists, transplant surgeons, interventional radiologists and hematologists. In this review, the authors provide a summary of the evidence supporting best clinical practices in the management of non-tumoral PVT in patients with cirrhosis.

Covered TIPS versus endoscopic band ligation plus propranolol for the prevention of variceal rebleeding in cirrhotic patients with portal vein thrombosis: a randomised controlled trial

OBJECTIVE

Limited data are available on the prevention of variceal rebleeding in cirrhotic patients with portal vein thrombosis (PVT). This study aimed to compare transjugular intrahepatic portosystemic shunt (TIPS) with covered stents versus endoscopic band ligation (EBL) plus propranolol for the prevention of variceal rebleeding among patients with cirrhosis and PVT.

DESIGN

Consecutive cirrhotic patients (94% Child-Pugh class A or B) with PVT who had variceal bleeding in the past 6 weeks were randomly assigned to TIPS group (n=24) or EBL plus propranolol group (EBL+drug, n=25), respectively. Primary endpoint was variceal rebleeding. Secondary endpoints included survival, overt hepatic encephalopathy (OHE), portal vein recanalisation and rethrombosis, other complications of portal hypertension and adverse events.

RESULTS

During a median follow-up of 30 months in both groups, variceal rebleeding was significantly less frequent in the TIPS group (15% vs 45% at 1 year and 25% vs 50% at 2 years, respectively; HR=0.28, 95% CI 0.10 to 0.76, p=0.008), with a significantly higher portal vein recanalisation rate (95% vs 70%; p=0.03) and a relatively lower rethrombosis rate (5% vs 33%; p=0.06) compared with the EBL+drug group. There were no statistically significant differences in survival (67% vs 84%; p=0.152), OHE (25% vs 16%; p=0.440), other complications of portal hypertension and adverse events between groups.

CONCLUSION

Covered TIPS placement in patients with PVT and moderately decompensated cirrhosis was more effective than EBL combined with propranolol for the prevention of rebleeding, with a higher probability of PVT resolution without increasing the risk of OHE and adverse effects, but this benefit did not translate into improved survival.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT01326949.

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

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION

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

Anticoagulation in chronic liver disease

In this Grand Round presentation, the case of a man with decompensated liver disease is described. He subsequently developed a fatal pulmonary embolism, which may not have occurred if he had been prescribed prophylactic anticoagulation to prevent venous thromboembolic disease. The burden of thrombotic disease in those with chronic liver disease is discussed, before a more detailed analysis of the current evidence, safety data, and clinical dilemmas regarding the use of anticoagulation in patients with chronic liver disease. Finally, the future directions within this field are explored.

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

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

Thrombin activation and liver inflammation in advanced hepatitis C virus infection

Hepatitis C virus (HCV) infection is associated with increased thrombotic risk. Several mechanisms are involved including direct endothelial damage by the HCV virus, with activation of tissue factor, altered fibrinolysis and increased platelet aggregation and activation. In advanced stages, chronic HCV infection may evolve to liver cirrhosis, a condition in which alterations in the portal microcirculation may also ultimately lead to thrombin activation, platelet aggregation, and clot formation. Therefore in advanced HCV liver disease there is an increased prevalence of thrombotic phenomena in portal vein radicles. Increased thrombin formation may activate hepatic stellate cells and promote liver fibrosis. In addition, ischemic changes derived from vascular occlusion by microthrombi favor the so called parenchymal extinction, a process that promotes collapse of hepatocytes and the formation of gross fibrous tracts. These reasons may explain why advanced HCV infection may evolve more rapidly to end-stage liver disease than other forms of cirrhosis.

PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q, and Prothrombin 20210A in Splanchnic Vein Thrombosis: Analysis of Individual Patient Data From Three Prospective Studies

BACKGROUND

There are no univocal opinions on the role of genetic thrombophilia on splanchnic vein thrombosis (SVT). We defined genetic thrombophilia the presence of one of these thrombophilic genetic factors (THRGFs): PAI-1 4G-4G, MTHFR 677TT, V Leiden 506Q, and prothrombin 20210A.

OBJECTIVES

To evaluate the frequencies of these THRGFs in SVT patients, we analyzed individual data of 482 Caucasian patients, recruited from 2000 to 2014 in three prospective studies. SVT was defined as the presence of thrombosis of portal (PVT), mesenteric (MVT), splenic (SPVT), cava (CT), and hepatic vein (Budd Chiari syndrome, BCS). Pre-hepatic SVT (pre-HSVT) was defined as PVT with or without MVT/SPVT, without BCS. Post-hepatic SVT (post-HSVT) was BCS with or without PVT/MVT/SPVT.

METHODS

We compared 350 patients with liver cirrhosis (LC), 47 hepatocellular carcinoma (HCC), 37 myeloproliferative neoplasm (MPN), 38 associated disease (AD), 10 without any associated disease (WAD), vs 150 healthy controls (HC); 437 patients showed pre-HSVT and 45 post-HSVT.

RESULTS

Thrombophilia was present in 294/482 (60.9%) patients: 189/350 LC (54.0%), 31/47 (66.0%) HCC, 29/39 (74.4%) MPN, 35/38 AD (92.1%), and 10/10 (100%) WAD, and 54/150 (36.0%) in HC. In the total group, we found 175 PAI-1 4G-4G, 130 MTHFR 677TT, 42V Leiden 506Q, and 27 prothrombin 20210A; 75 patients showed presence of >1 TRHGF; the more frequent association was PAI-1 4G-4G/MTHFR 677TT, in 36 patients. PAI-1 4G-4G and MTHFR 677TT were significantly more frequent in patients with SVT (P values <0.005), whereas V Leiden Q506 and prothrombin G20210A were not. PAI-1 4G-4G and MTHFR 677TT distributions deviated significantly from that expected from a population in Hardy-Weinberg equilibrium. Thrombophilia was significantly less frequent in patients with pre-HSVT (250/437, 57.2%) than in patients with post-HSVT (44/45, 97.8%).

CONCLUSIONS

Our study shows the significant prevalence of PAI-1 4G-4G and MTHFR 677TT in SVT, mainly in post-HSVT.

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.