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

Machine learning prediction of hepatic encephalopathy for long-term survival after transjugular intrahepatic portosystemic shunt in acute variceal bleeding

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) is an effective intervention for managing complications of portal hypertension, particularly acute variceal bleeding (AVB). While effective in reducing portal pressure and preventing rebleeding, TIPS is associated with a considerable risk of overt hepatic encephalopathy (OHE), a complication that significantly elevates mortality rates.

AIM

To develop a machine learning (ML) model to predict OHE occurrence post-TIPS in patients with AVB using a 5-year dataset.

METHODS

This retrospective single-center study included 218 patients with AVB who underwent TIPS. The dataset was divided into training (70%) and testing (30%) sets. Critical features were identified using embedded methods and recursive feature elimination. Three ML algorithms-random forest, extreme gradient boosting, and logistic regression-were validated via 10-fold cross-validation. SHapley Additive exPlanations analysis was employed to interpret the model's predictions. Survival analysis was conducted using Kaplan-Meier curves and stepwise Cox regression analysis to compare overall survival (OS) between patients with and without OHE.

RESULTS

The median OS of the study cohort was 47.83 ± 22.95 months. Among the models evaluated, logistic regression demonstrated the highest performance with an area under the curve (AUC) of 0.825. Key predictors identified were Child-Pugh score, age, and portal vein thrombosis. Kaplan-Meier analysis revealed that patients without OHE had a significantly longer OS (P = 0.005). The 5-year survival rate was 78.4%, with an OHE incidence of 15.1%. Both actual OHE status and predicted OHE value were significant predictors in each Cox model, with model-predicted OHE achieving an AUC of 88.1 in survival prediction.

CONCLUSION

The ML model accurately predicts post-TIPS OHE and outperforms traditional models, supporting its use in improving outcomes in patients with AVB.

Portal Vein Thrombosis in Liver Cirrhosis. Part 2: Treatment, Primary and Secondary Prevention

In most cases, portal vein thrombosis progresses without treatment; spontaneous recanalization of portal vein develops in 42 % of patients with liver cirrhosis. Effective treatment strategies include administration of anticoagulants, interventional procedures such as transjugular intrahepatic porto-systemic shunt or endovascular fibrinolysis. Anticoagulant therapy has certain difficulties in patients with liver cirrhosis due to the complex profile of hemostasis, a tendency to both hemorrhages and hypercoagulation. In addition to traditional anticoagulants (heparin preparations, fondaparinux, vitamin K antagonists), direct oral anticoagulants have been widely used in recent years for portal vein thrombosis. Previously, portal vein thrombosis was considered a contraindication to performing transjugular intrahepatic porto-systemic shunt, currently the method is often used to restore portal blood flow through the shunt and prevent repeated thrombosis. Endovascular fibrinolysis is still an option for specialized centers for «difficult» patients. In cases of increased risk of venous thromboembolism, patients with liver cirrhosis are recommended to be prevented with low-molecular-weight heparin or direct oral anticoagulants, but further studies should clarify their effectiveness in this aspect. The review highlights data on the features of therapy, primary and secondary prevention of portal vein thrombosis in patients with liver cirrhosis. Despite the existing clinical recommendations for management of patients with cirrhotic portal vein thrombosis, the choice of a particular strategy primarily depends on an individualized assessment of risks and benefits of each treatment method.

Classification and Management of Portal Vein Thrombosis in Cirrhotic Patients: A Narrative Review

Portal vein thrombosis (PVT) poses significant therapeutic challenges due to its complex pathophysiology and diverse clinical presentations. Recent advancements have spurred the development of new therapeutic approaches to enhance treatment efficacy and safety. This review synthesized emerging therapies for PVT based on a comprehensive literature search across major databases such as PubMed, EMBASE, and Web of Science, among others, focusing on studies published in the last decade. Anticoagulation therapy, particularly with novel oral anticoagulants (NOACs), emerged as beneficial in personalized treatment regimens. Innovative surgical techniques and improved risk stratification methods were identified as crucial in the perioperative management of PVT. Additionally, advances in cell therapy and medical treatments for hepatocellular carcinoma in the context of PVT were explored. Promising outcomes were observed with modalities such as Yttrium 90 and liver transplantation combined with thrombectomy, particularly in complex PVT cases associated with hepatocellular carcinoma, albeit on a limited scale. The reviewed literature indicates a shift towards individualized treatment approaches for PVT, integrating novel anticoagulants, refined risk assessment tools, and tailored interventional strategies. While these emerging therapies show potential for enhanced efficacy and safety, further research is essential to validate findings across broader patient populations and establish standardized treatment protocols.

Management of Nonmalignant Portal Vein Thrombosis in Cirrhosis

Nonmalignant portal vein thrombosis (PVT) is a common complication of cirrhosis especially at the stage of decompensations. The diagnosis of PVT in cirrhosis is often incidental and it may be detected during routine semestral abdominal ultrasound with Doppler during screening for hepatocellular carcinoma or during hospitalization for decompensated cirrhosis. After detection of PVT on abdominal ultrasound, it is important to evaluate patients with cross-sectional imaging to determine the age of thrombus, whether acute or chronic, the extent and degree of luminal occlusion of the portal vein, and to rule out hepatocellular carcinoma or other underlying malignancy. Factors influencing management include the degree and extent of luminal occlusion of PVT, potential listing for liver transplantation, and portal hypertension (PHT) complications such as variceal hemorrhage and refractory ascites, severity of thrombocytopenia, and other comorbidities including chronic kidney disease. Anticoagulation is the most common therapeutic option and it is specially indicated in patients who are candidates for liver transplantation. Interventional procedures including transjugular intrahepatic portosystemic shunt (TIPS) placement and mechanical thrombectomy may be used on a case-by-case basis in patients with contraindications or adverse events related to anticoagulation, who develop worsening PVT while on anticoagulant therapy, or have chronic PVT and PHT complications that are not manageable medically or endoscopically.

Bacterial infections as a risk factor for non-neoplastic portal vein thrombosis development in cirrhotic patients

BACKGROUND

Portal vein thrombosis (PVT) and sepsis are common complications in patients with liver cirrhosis. Factors that lead to PVT are not completely understood. This study aimed to investigate the possible association between bacterial infections and the development of PVT in cirrhotic patients.

PATIENTS AND METHODS

202 consecutive cirrhotic patients without previous infections, followed at the Liver Unit in Verona Hospital, were enrolled from 2017 to 2021 (median follow-up 3.3 years). During the follow-up period, PVT was diagnosed by ultrasound, CT and/or MRI, and episodes of bacterial infections requiring hospitalization were recorded. Malignant PVT was an exclusion criterion.

RESULTS

Of the 202 patients enrolled (68.3 % males, mean age 63.8 ± 11 years), 22 (10.8 %) developed PVT during the follow up. In patients with PVT, the prevalence of previous bacterial infections was significantly higher compared to patients without PVT (63.6% vs 31.1 %; p = 0.02). Cox regression analysis revealed that a history of bacterial infection was the only variable that demonstrated a significant association with the risk of de novo PVT occurrence (HR 4.04, 95 % CI: 1.68-9.65).

CONCLUSION

in patients with liver cirrhosis bacterial infections are a predisposing factor for the following development of PVT. Further studies are needed to confirm this evidence.

Diagnostic Prediction of portal vein thrombosis in chronic cirrhosis patients using data-driven precision medicine model

BACKGROUND

Portal vein thrombosis (PVT) is a significant issue in cirrhotic patients, necessitating early detection. This study aims to develop a data-driven predictive model for PVT diagnosis in chronic hepatitis liver cirrhosis patients.

METHODS

We employed data from a total of 816 chronic cirrhosis patients with PVT, divided into the Lanzhou cohort (n = 468) for training and the Jilin cohort (n = 348) for validation. This dataset encompassed a wide range of variables, including general characteristics, blood parameters, ultrasonography findings and cirrhosis grading. To build our predictive model, we employed a sophisticated stacking approach, which included Support Vector Machine (SVM), Naïve Bayes and Quadratic Discriminant Analysis (QDA).

RESULTS

In the Lanzhou cohort, SVM and Naïve Bayes classifiers effectively classified PVT cases from non-PVT cases, among the top features of which seven were shared: Portal Velocity (PV), Prothrombin Time (PT), Portal Vein Diameter (PVD), Prothrombin Time Activity (PTA), Activated Partial Thromboplastin Time (APTT), age and Child-Pugh score (CPS). The QDA model, trained based on the seven shared features on the Lanzhou cohort and validated on the Jilin cohort, demonstrated significant differentiation between PVT and non-PVT cases (AUROC = 0.73 and AUROC = 0.86, respectively). Subsequently, comparative analysis showed that our QDA model outperformed several other machine learning methods.

CONCLUSION

Our study presents a comprehensive data-driven model for PVT diagnosis in cirrhotic patients, enhancing clinical decision-making. The SVM-Naïve Bayes-QDA model offers a precise approach to managing PVT in this population.

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.

ADAMTS-13/von Willebrand factor ratio: A prognostic biomarker for portal vein thrombosis in compensated cirrhosis. A prospective observational study

BACKGROUND AND AIMS

In cirrhosis, decreased portal flow velocity, thrombophilia factors, and portal hypertension are considered risk factors for portal vein thrombosis (PVT). In cirrhosis, the transformation of the stellate cells causes a progressive decrease of ADAMTS-13, while VWF multimers secretion by endothelial cells is strongly enhanced. This imbalance leads to an accumulation of ultra-large VWF multimers that in sinusoidal circulation could favor PVT both in intra- and extra-hepatic branches, mostly in decompensated cirrhosis. This prospective study was aimed at identifying possible clinical, biochemical, and hemostatic factors predictive for non-tumoral PVT in a cohort of patients with compensated cirrhosis.

METHODS

Seventynine compensated cirrhosis patients were prospectively followed for 48 months, receiving a periodic Doppler-ultrasound liver examination associated with an extensive evaluation of clinical, biochemical, and hemostatic profile.

RESULTS

Five patients developed PVT (cumulative prevalence = 6.3%), occurring 4-36 months after enrollment. In logistic regression analysis, the ADAMTS-13/VWF:GpIbR ratio < 0.4 was the only independent variable significantly associated with PVT (OR 14.6, 95% C.I.:1.36-157.2, p = 0.027). A Cox-regression-analysis confirmed this finding (HR = 7.7, p = 0.027).

CONCLUSIONS

The ADAMTS-13/VWF ratio < 0.4 measured in compensated cirrhosis could be a reliable predictive biomarker for PVT development, paving the way to novel therapeutic strategies to prevent and treat PVT in this clinical setting.

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.

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

BACKGROUND

A hypercoagulable state is not associated with development of portal vein thrombosis in cirrhosis, as we previously demonstrated. However, some groups demonstrated elevated levels of inflammatory markers and activation of hemostasis in the portal vein (PV) compared to posthepatic veins, but because the liver is involved in clearance of these markers, we hypothesize that interpretation of these data is not straightforward.

AIM

To determine whether the PV has particular proinflammatory/hypercoagulable characteristics by comparing plasma sampled in the PV, hepatic vein (HV), and the systemic circulation.

METHODS

Plasma samples from 51 cirrhotic patients with portal hypertension undergoing transjugular intrahepatic portosystemic shunt placement, were taken from the PV, HV, and jugular vein (JV). Markers of inflammation (lipopolysaccharide, tumor necrosis factor-α, interleukin-6, thiobarbituric acid-reactive substances), neutrophil-extracellular-traps (cfDNA, MPO-DNA), endothelial damage (von Willebrand factor [VWF]), and hemostasis were determined and compared among the three vascular beds.

RESULTS

Markers of inflammation were slightly, but significantly higher in the PV than in the HV and systemic circulation. VWF and markers of hemostasis were modestly elevated in the PV. Levels of multiple markers were lower in the HV compared with the PV and systemic circulation. Higher model for end-stage liver disease score was associated with a more prothrombotic state in all three sample sites.

CONCLUSION

In contrast to published studies, we did not detect a clear proinflammatory or prothrombotic environment in the PV of cirrhotic patients. Many markers are lowest in the HV, indicating that the low levels of these markers in the HV, at least in part, reflect clearance of those markers in the liver.

Direct oral anticoagulant administration in cirrhotic patients with portal vein thrombosis: What is the evidence?

In recent years, the traditional concept that cirrhosis-related coagulopathy is an acquired bleeding disorder has evolved. Currently, it is known that in cirrhotic patients, the hemostatic system is rebalanced, which involves coagulation factors, fibrinolysis and platelets. These alterations disrupt homeostasis, skewing it toward a procoagulant state, which can lead to thromboembolic manifestations, especially when hemodynamic and endothelial factors co-occur, such as in the portal vein system in cirrhosis. Portal vein thrombosis is a common complication of advanced liver cirrhosis that negatively affects the course of liver disease, prognosis of cirrhotic patients and success of liver transplantation. It is still debated whether portal vein thrombosis is the cause or the consequence of worsening liver function. Anticoagulant therapy is the mainstay treatment for acute symptomatic portal vein thrombosis. In chronic portal vein thrombosis, the role of anticoagulant therapy is still unclear. Traditional anticoagulants, vitamin K antagonists and low-molecular-weight heparin are standard-of-care treatments for portal vein thrombosis. In the last ten years, direct oral anticoagulants have been approved for the prophylaxis and treatment of many thromboembolic-related diseases, but evidence on their use in cirrhotic patients is very limited. The aim of this review was to summarize the evidence about the safety and effectiveness of direct oral anticoagulants for treating portal vein thrombosis in cirrhotic patients.

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.

The Pathophysiology of Portal Vein Thrombosis in Cirrhosis: Getting Deeper into Virchow's Triad

Portal vein thrombosis (PVT) is a common complication among patients with cirrhosis. However, its pathophysiology is not well established and there are currently very few predictive factors, none of which are actually useful, from a clinical perspective. The contribution of each of the vertices of Virchow’s triad, e.g., blood hypercoagulability, blood flow, and portal vein endothelial damage in the development of PVT is not clear. In this review, we aim to recapitulate the latest studies on the field of PVT development in order to understand its mechanisms and discuss some of the future directions in the study of this important complication of cirrhosis.

Evolution of Nonmalignant Portal Vein Thrombosis in Liver Cirrhosis: A Pictorial Review

Portal vein thrombosis (PVT) is a common complication in liver cirrhosis, especially in advanced cirrhosis. It may be related to a higher risk of liver-related events and liver function deterioration. Imaging examinations can not only provide an accurate diagnosis of PVT, such as the extent of thrombus involvement and the degree of lumen occupied, but also identify the nature of thrombus (i.e., benign/malignant and acute/chronic). Evolution of PVT, mainly including development, recanalization, progression, stability, and recurrence, could also be assessed based on the imaging examinations. This article briefly reviews the pathophysiology, diagnosis, classification, and evolution of PVT with an emphasis on their computed tomography imaging features.

Transjugular intrahepatic portosystemic shunts in portal vein thrombosis: A review

The presence of portal vein thrombosis (PVT) has previously been considered a contraindication to the insertion of transjugular intrahepatic portosystemic shunts (TIPSS). However, patients with PVT may have portal hypertension complications and may thus benefit from TIPSS to reduce portal venous pressure. There is an increasing body of literature that discusses the techniques and outcomes of TIPSS in PVT. This review summarizes the techniques, indications and outcomes of TIPSS in PVT in published case reports, case series and comparative trials, especially regarding the reduction in portal hypertensive complications such as variceal bleeding. A comprehensive literature search was conducted using MEDLINE and PubMed databases. Manuscripts published in English between 1 January 1990 and 1 March 2021 were used. Abstracts were screened and data from potentially relevant articles analyzed. TIPSS in PVT has been reported with high levels of technical success, short-term portal vein recanalization and long-term PV patency and TIPSS patency outcomes. Several comparative studies, including randomized controlled trials, have shown favorable outcomes of TIPSS compared with non-TIPSS treatment of PVT complications. Outcomes of TIPSS with PVT appear similar to those in TIPSS without PVT. However, TIPSS may be more technically difficult in the presence of PVT, and such procedures should be performed in expert high-volume centers to mitigate the risk of procedural complications. The presence of PVT should no longer be considered a contraindication to TIPSS. TIPSS for PVT has been acknowledged as a therapeutic strategy in recent international guidelines, although further studies are needed before recommendations can be strengthened. KEY POINTS: Portal vein thrombosis (PVT) is no longer a contraindication to the insertion of transjugular intrahepatic portosystemic shunts (TIPSS) TIPSS often leads to the spontaneous dissolution of PVT, but can be combined with mechanical or pharmacological thrombectomy TIPSS reduces portal hypertensive complications of PVT, such as variceal bleeding, and can also facilitate liver transplantation where PVT may otherwise interfere with vascular anastomoses Studies have shown favorable long-term outcomes of TIPSS compared with TIPSS without PVT; as well as compared with non-TIPSS treatment of PVT complications TIPSS in PVT should be performed in high-volume specialist centers due to technical difficulties.

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.

Pfortaderthrombosen – therapeutische Möglichkeiten

Die Pfortaderthrombose ist eine seltene Erkrankung, die eine Thrombose im Zustromgebiet der Pfortader in die Leber beschreibt bzw. in der Leber selbst in den entsprechenden Pfortaderästen lokalisiert ist. Oftmals liegt bereits eine chronische Lebererkrankung bzw. ein Malignom der Leber selbst oder unmittelbar benachbart liegender Organe vor; die Pfortaderthrombose kann aber auch bei Patienten auftreten, die keine entsprechende Vorerkrankung haben. Bei jeder neu diagnostizierten Pfortaderthrombose gilt es zu entscheiden, ob unmittelbar oder im Verlauf eine radiologisch-interventionelle Rekanalisation vorgenommen wird oder ein rein konservativer Therapieversuch mit Antikoagulanzien erfolgt. Aber auch chirurgische Verfahren, wie eine Shuntanlage oder die Notwendigkeit einer Lebertransplantation, müssen hierbei berücksichtigt werden. Für diesen Therapiealgorithmus ist die Kontaktaufnahme mit einem entsprechenden Zentrum sinnvoll. Die Therapieentscheidung muss die Ursache der Pfortaderthrombose und die Begleiterkrankungen adäquat berücksichtigen.