The portal vein in patients with cirrhosis is not an excessively inflammatory or hypercoagulable vascular bed, a prospective cohort study

Non-invasive assessment of portal hypertension: Liver stiffness and beyond

Portal hypertension (PH) leads to life-threatening clinical manifestations such as bleeding from gastro-oesophageal varices, ascites and its complications, and portosystemic encephalopathy. It can develop because of advanced chronic liver disease (ACLD) or due to rarer causes such as vascular liver disease. Reference standard methods to assess PH in ACLD include the measurement of hepatic venous pressure gradient and endoscopy, which have limitations due to their high resource utilisation and invasiveness. Non-invasive tests (NITs) have entered clinical practice and allow invasive procedures to be reserved for patients with indeterminate findings on NITs or for specific clinical questions. In this review, we present an update on the role of NITs, and in particular ultrasound elastography, to diagnose PH in ACLD and vascular liver disease, and to stratify the risk of liver-related events. We also provide insights into the open research questions and design of studies in this field.

Experience With Dabigatran on Rate of Portal Vein Thrombosis Recanalization, Disease Progression and Survival

BACKGROUND AND AIMS

We assessed clinical, procoagulant and genetic risk factors and clinical outcomes in dabigatran-treated patients with non-tumoural acute and acute-on-chronic portal vein thrombosis (PVT).

METHODS

Patients with a new diagnosis of non-tumoural acute and acute-on-chronic PVT between January 2021 and January 2024 (aged ≥ 18 years) in those without/with cirrhosis (Child-Pugh (CP)-A/B/C ≤ 10) were started on dabigatran and followed and compared with those on vitamin K antagonist (VKA) and untreated individuals.

RESULTS

Dabigatran was prescribed in 119 patients with PVT type 1 (61, 51.3%), type 2 (34, 28.6%), type 3 (24, 20.2%); 72 (60.5%) with cirrhosis [CP-A (27, 37.5%), CP-B (43, 59.7%) and CP-C10 (2, 2.8%)]. Procoagulant factors noted were JAK2V617F (10.1%), CALR (2.5%) and factor V Leiden (1.6%) mutations, antiphospholipid syndrome (APS, 15.2%), isolated Protein C (14.3%) and Protein S (16.8%) deficiency.

COMPARATORS

28 patients who declined anticoagulation/were unable to come for follow-up, and six with CP-C received VKA. Overall recanalization rate (RR) on dabigatran was 56 (47.1%); 25 (21%) complete recanalization, 31 (26%) partial recanalization and 63 (52.9%) stable PVT over median follow-up of 32 months. Patients not anticoagulated had a spontaneous RR in 21.4% (28 patients; p = 0.005 compared with dabigatran group) and none recanalized on VKA. On multivariable analysis, predictors of recanalization on dabigatran were Factor VIII Antigen level (FVIII:Ag, HR 0.6; 95% CI 0.3-0.9, p = 0.032), non-occlusive PVT (HR 3.5, 95% CI 1.9-5.6, p = 0.025) and acute PVT (HR 2.1; 95% CI 1.5-3.2, p = 0.003). Mortality was 14 (11.8%).

CONCLUSION

On dabigatran, 47% of 119 patients achieved portal vein recanalization over 32 months of follow-up which was higher than the spontaneous RR (21.4%) in an untreated cohort. High Factor VIII:Ag was a predictor of non-recanalization. Dabigatran was safe in cirrhosis (CP-A and B) while further work is needed in CP-C.

Gut microbiome dysbiosis is not associated with portal vein thrombosis in patients with end-stage liver disease: a cross-sectional study

BACKGROUND

Portal vein thrombosis (PVT) is a common complication in patients with end-stage liver disease (ESLD). The portal vein in patients with ESLD is proposedly an inflammatory vascular bed due to translocation of endotoxins and cytokines from the gut. We hypothesized that a proinflammatory gut microbiome and elevated trimethylamine N-oxide (TMAO), a driver of thrombosis, may contribute to PVT development.

OBJECTIVES

We investigated whether gut microbiome diversity, bacterial species, metabolic pathways, and TMAO levels are associated with PVT in patients with ESLD.

METHODS

Fecal samples, plasma samples, and data from patients with ESLD and healthy controls were collected through the TransplantLines Biobank and Cohort Study. PVT was defined as a thrombus in the portal vein within a year prior to or after fecal sample collection. Fecal samples were analyzed using Shotgun Metagenomic Sequencing, and TMAO levels were measured in plasma using a Vantera Clinical Analyzer.

RESULTS

One hundred two patients with ESLD, of which 23 with PVT, and 246 healthy controls were included. No significant difference in gut microbiome diversity was found between patients with PVT and without PVT (P = .18). Both ESLD groups had significantly lower alpha diversity than controls. Bacteroides fragilis and 3 Clostridiales species were increased in patients with PVT compared with without PVT. TMAO levels between the 3 groups were not significantly different.

CONCLUSION

We observed profound differences in gut microbiota between patients with ESLD and controls, but minimal differences between patients with ESLD with or without PVT. In our cohort, a gut-derived proinflammatory state was not associated with presence of PVT in patients with ESLD.

Predictive value of hepatic venous pressure gradient in cirrhotic portal vein thrombosis development

BACKGROUND & AIMS

There are lots of risk factors reported for cirrhotic portal vein thrombosis (PVT) development, however, the relationship between hepatic venous pressure gradient (HVPG) and PVT development remains unclear.

METHODS

The clinical outcomes of cirrhotic patients who had no PVT and underwent HVPG measurement at baseline between March 2018 and March 2022 were analyzed retrospectively. Screening for non-tumoral PVT development was implemented by contrast-enhanced computed tomography and/or magnetic resonance imaging every 6-12 months.

RESULTS

Eighty-two cirrhotic patients were evaluated over a follow-up period. Of these, 12 patients (14.6%) experienced the development of PVT. The occurrence of non-tumoral PVT at one, two, and three years were 6.6%, 11.7%, and 22.2% respectively. HVPG (p=0.038;HR 1.07;95%CI 1.00-1.14) and alcohol liver disease (ALD) (p=0.019;HR 4.20;95%CI 1.27-13.89) were independently associated with a high PVT risk. The cutoff value of HVPG was 17.52 mmHg. The cumulative incidence of PVT differed significantly among groups stratified by HVPG thresholds of 16mmHg (P=0.011). The sensitivity and specificity of HVPG≥16mmHg in predicting PVT development were 100.0% and 35.7%.

CONCLUSIONS

In patients with liver cirrhosis, the value of HVPG was the independent predictive factor of PVT development. Screening for PVT was recommended during follow-up in patients with HVPG≥16 mmHg.

Causal Relationships of Circulating Inflammatory Proteins and Portal Vein Thrombosis: A Mendelian Randomization Study

Portal vein thrombosis (PVT) is commonly encountered in patients with cirrhosis, challenging our understanding of its development, particularly the ambiguous contribution of inflammation. This study utilized Mendelian randomization (MR) to explore the causal impact of circulating inflammatory markers on PVT.Employing a two-sample MR framework, we merged genome-wide association study (GWAS) meta-analysis findings of 91 inflammation-associated proteins with independent PVT data from the FinnGen consortium's R10 release. A replication analysis was performed using a distinct GWAS dataset from the UK Biobank. Inverse variance weighting, MR-Egger regression, weighted median estimator, and Mendelian Randomization Pleiotropy RESidual Sum and Outlier were used for analysis, supplemented by multivariable MR (MVMR) to adjust for cirrhosis effects.Findings indicate a significant inverse association between the genetically inferred concentration of eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) and PVT risk, evidenced by an odds ratio (OR) of 0.37 (95% confidence interval [CI]: 0.21-0.67; p = 9.2 × 10-4; adjusted for multiple testing p = 0.084). This association was corroborated in the replication phase (OR = 0.39, 95% CI: 0.17-0.93; p = 0.03) and through MVMR analysis (OR = 0.34, 95% CI: 0.15-0.79; p = 0.012). Sensitivity analyses disclosed no evidence of heterogeneity or pleiotropy.Our investigation emphasizes the 4E-BP1 as a protective factor against PVT, underscoring its potential relevance in understanding PVT pathogenesis and its implications for diagnosis and therapy.

Portal vein thrombosis: diagnosis, management, and endpoints for future clinical studies

Portal vein thrombosis (PVT) refers to the development of a non-malignant obstruction of the portal vein, its branches, its radicles, or a combination. This Review first provides a comprehensive overview of all aspects of PVT, namely the specifics of the portal venous system, the risk factors for PVT, the pathophysiology of portal hypertension in PVT, the interest in non-invasive tests, as well as therapeutic approaches including the effect of treating risk factors for PVT or cause of cirrhosis, anticoagulation, portal vein recanalisation by interventional radiology, and prevention and management of variceal bleeding in patients with PVT. Specific issues are also addressed including portal cholangiopathy, mesenteric ischaemia and intestinal necrosis, quality of life, fertility, contraception and pregnancy, and PVT in children. This Review will then present endpoints for future clinical studies in PVT, both in patients with and without cirrhosis, agreed by a large panel of experts through a Delphi consensus process. These endpoints include classification of portal vein thrombus extension, classification of PVT evolution, timing of assessment of PVT, and global endpoints for studies on PVT including clinical outcomes. These endpoints will help homogenise studies on PVT and thus facilitate reporting, comparison between studies, and validation of future studies and trials on PVT.

Association between endotoxemia and blood no in the portal circulation of cirrhotic patients: results of a pilot study

Pathophysiology of portal vein thrombosis (PVT) in cirrhosis is still not entirely understood. Elevated levels of lipopolysaccharides (LPS) in portal circulation are significantly associated with hypercoagulation, increased platelet activation and endothelial dysfunction. The aim of the study was to investigate if LPS was associated with reduced portal venous flow, the third component of Virchow's triad, and the underlying mechanism. Serum nitrite/nitrate, as a marker of nitric oxide (NO) generation, and LPS were measured in the portal and systemic circulation of 20 patients with cirrhosis undergoing transjugular intrahepatic portosystemic shunt (TIPS) procedure; portal venous flow velocity (PVV) was also measured in each patient and correlated with NO and LPS levels. Serum nitrite/nitrate and LPS were significantly higher in the portal compared to systemic circulation; a significant correlation was found between LPS and serum nitrite/nitrate (R = 0.421; p < 0.01). Median PVV before and after TIPS was 15 cm/s (6-40) and 31 cm/s (14-79), respectively. Correlation analysis of PVV with NO and LPS showed a statistically significant negative correlation of PVV with portal venous NO concentration (R = - 0.576; p = 0.020), but not with LPS. In vitro study with endothelial cells showed that LPS enhanced endothelial NO biosynthesis, which was inhibited by L-NAME, an inhibitor of NO synthase, or TAK-242, an inhibitor of TLR4, the LPS receptor; this effect was accomplished by up-regulation of eNOS and iNOS. The study shows that in cirrhosis, endotoxemia may be responsible for reduced portal venous flow via overgeneration of NO and, therefore, contribute to the development of PVT.

Predicting de-novo portal vein thrombosis after HCV eradication: A long-term competing risk analysis in the ongoing PITER cohort

BACKGROUND & AIMS

Sustained virological response (SVR) by direct-acting antivirals (DAAs) may reverse the hypercoagulable state of HCV cirrhosis and the portal vein thrombosis (PVT) risk. We evaluated the incidence and predictive factors of de novo, non-tumoral PVT in patients with cirrhosis after HCV eradication.

METHODS

Patients with HCV-related cirrhosis, consecutively enrolled in the multi-center ongoing PITER cohort, who achieved the SVR using DAAs, were prospectively evaluated. Kaplan-Meier and competing risk regression analyses were performed.

RESULTS

During a median time of 38.3 months (IQR: 25.1-48.7 months) after the end of treatment (EOT), among 1609 SVR patients, 32 (2.0%) developed de novo PVT. A platelet count ≤120,000/μL, albumin levels ≤3.5 mg/dL, bilirubin >1.1 mg/dL, a previous liver decompensation, ALBI, Baveno, FIB-4, and RESIST scores were significantly different (p < 0.001), among patients who developed PVT versus those who did not. Considering death and liver transplantation as competing risk events, esophageal varices (subHR: 10.40; CI 95% 4.33-24.99) and pre-treatment ALBI grade ≥2 (subHR: 4.32; CI 95% 1.36-13.74) were independent predictors of PVT. After HCV eradication, a significant variation in PLT count, albumin, and bilirubin (p < 0.001) versus pre-treatment values was observed in patients who did not develop PVT, whereas no significant differences were observed in those who developed PVT (p > 0.05). After the EOT, esophageal varices and ALBI grade ≥2, remained associated with de novo PVT (subHR: 9.32; CI 95% 3.16-27.53 and subHR: 5.50; CI 95% 1.67-18.13, respectively).

CONCLUSIONS

In patients with HCV-related cirrhosis, a more advanced liver disease and significant portal hypertension are independently associated with the de novo PVT risk after SVR.

Comparison of Inflammatory Cytokine Levels in Hepatic and Jugular Veins of Patients with Cirrhosis

Background

Systemic inflammation with elevated inflammatory cytokines is a hallmark in patients with cirrhosis and the main driver of decompensation. There is insufficient data on whether inflammatory cytokine levels differ between hepatic and jugular veins, which may have implications for further immunological studies.

Methods

Blood from the hepatic and jugular veins of 40 patients with cirrhosis was collected during hepatic venous pressure gradient (HVPG) measurements. Serum levels of 13 inflammatory cytokines (IL-1β, Int-α2, Int-γ, TNF-α, MCP-1, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IL-18, IL-23, and IL-33) were quantified by cytometric bead array.

Results

Cytokine levels of IFN-α2, IFN-γ, TNF-α, IL-6, IL-8, IL-10, IL-17A, IL-18, IL-23, and IL-33 were significantly elevated in patients with decompensated cirrhosis compared to patients with compensated cirrhosis. When comparing patients with clinically significant portal hypertension (CSPH, HVPG ≥ 10 mmHg) to patients without CSPH, there were significantly enhanced serum levels of IL-6 and IL-18 in the former group. There was no significant difference between cytokine serum levels between blood obtained from the jugular versus hepatic veins. Even in subgroup analyses stratified for an early cirrhosis stage (Child-Pugh (CP) A) or more decompensated stages (CP B/C), cytokine levels were similar.

Conclusion

Cytokine levels increase with decompensation and increasing portal hypertension in patients with cirrhosis. There is no relevant difference in cytokine levels between hepatic and jugular blood in patients with cirrhosis.

Portal vein thrombosis in liver cirrhosis: An updated overview

Portal vein thrombosis (PVT) is a frequent and severe complication in patients with cirrhosis; however, the pathophysiology of PVT needs to be better clarified. There are few significant predictive factors in clinical practice, and the impact of PVT on cirrhosis progression and its complications, such as gastrointestinal bleeding, hepatic encephalopathy, and hepatorenal syndrome, remains uncertain. In recent years, the understanding of the mechanisms of PVT has become more profound with the publication of related literature. Therefore, in this review, we aim to summarize the advanced progress in the epidemiology, hazards, risk factors, diagnosis and classification, and treatment of PVT to provide insight into clinical management.

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.

Anticoagulant therapy for splanchnic vein thrombosis: recent updates for patients with liver cirrhosis

INTRODUCTION

Liver cirrhosis is accompanied by several hemostatic alterations, which contribute to the current theory of "rebalanced hemostasis." Splanchnic vein thrombosis (SVT) is a frequent complication of liver cirrhosis (17-26% of the cirrhotic patients), and liver cirrhosis is a common risk factor for SVT (24-28% of SVT cases).

AREAS COVERED

This narrative review aims to describe the current state of the art on the anticoagulant treatment of cirrhotic SVT, with a particular focus on the possible role of the direct oral anticoagulants (DOACs) and recent guidelines on this topic.

EXPERT OPINION

Early anticoagulant therapy is recommended in cirrhotic patients with acute SVT, to obtain vessel recanalization and decrease the rates of portal hypertension-related complications. Gastroesophageal varices do not represent a contraindication to anticoagulation, if adequate prophylaxis of variceal bleeding is established, and varices band ligation can be safely performed without the need to stop the anticoagulant treatment. The conventional treatment of cirrhotic SVT consisted of low molecular weight heparin, as initial treatment of choice, eventually followed by vitamin K antagonists, but the DOACs can be considered as a reasonable alternative in patients with compensated liver cirrhosis.

Increased platelet ratio in patients with decompensated cirrhosis indicates a higher risk of portal vein thrombosis

Patients with decompensated cirrhosis are at risk of portal vein thrombosis (PVT). We prospectively investigated whether alterations of platelet aggregation can predict PVT in decompensated cirrhosis. At baseline, all patients underwent whole-blood aggregometry (Multiplate®) to assess ADP-induced platelet aggregation. Aggregometry results were expressed as the ratio between platelet aggregation and platelet count (PLT ratio). Then, patients with cirrhosis were prospectively followed for 1 year for PVT development. One-hundred and twenty-eight patients with decompensated cirrhosis were included (Child-Pugh A/B/C 12/39/49%). The cumulative incidence of PVT was 14%. On multivariate analysis, the PLT ratio (OR 4.5, 95% CI 2.63-7.67; p < .0001) and Child-Pugh C versus A/B (OR 4.1, 95% CI 1.18-14.80; p = .03) were independently associated with PVT. The discriminative ability of the PLT ratio was higher than Child-Pugh (AUC 0.92 vs 0.70, p < .0001). A PLT ratio > 0.75 had 83% sensitivity and 84% specificity for PVT. In conclusion, the PLT ratio by Multiplate® seems a promising thrombotic biomarker in decompensated cirrhosis.

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.