Up to 50% of portal vein thrombosis remains undiagnosed until liver transplantation

Portal vein thrombosis and liver transplantation: management, matching, and outcomes. A retrospective multicenter cohort study

BACKGROUND AND AIMS

Besides the increased risk of perioperative morbidity, graft failure, and mortality, the majority of PVT are diagnosed at liver transplantation (LT). Improving preoperative management and patient selection may lead to better short-term and long-term outcomes and reduce the risk of a futile LT. The authors aimed to identify predictors of adverse outcomes after LT in patients with nonmalignant portal vein thrombosis (PVT) and improve donor to recipient matching by analyzing the results of the Italian cohort of LT recipients.

METHODS

Adult patients who underwent LT in Italy between January 2000 and February 2020 diagnosed with PVT pre-LT or at time of LT were considered eligible for inclusion. Based on a survey encompassing all 26 surgeons participating in the study, a binary composite outcome was defined. Patients were classified as having the composite event if at least one of these conditions occurred: operative time more than 600 min, estimated blood loss greater than 5000 ml, more than 20 ICU days, 90 days mortality, 90 days retransplant.

RESULTS

Seven hundred fourteen patients were screened and 698 met the inclusion criteria. The analysis reports the results of 568 patients that fulfilled the criteria to enter the composite outcome analysis.Overall, 156 patients (27.5%) developed the composite outcome. PVT stage 3/4 at transplant and need for any surgical correction of PVT are independent predictors of the composite outcome occurrence. When stratified by PVT grade, overall survival at 1-year ranges from 89.0% with PVT grade 0/1 to 67.4% in patients with PVT grade 3/4 at LT ( P <0.001). Nevertheless, patients with severe PVT can improve their survival when identified risk factors are not present.

CONCLUSIONS

Potential LT candidates affected by PVT have a benefit from LT that should be adequately balanced on liver function and type of inflow reconstruction needed to mitigate the incidence of adverse events. Nonetheless, the absence of specific risk factors may improve the outcomes even in patients with PVT grades 3-4.

How to manage splanchnic vein thrombosis in patients with liver disease

Liver cirrhosis and splanchnic vein thrombosis (SVT) are strictly correlated. Portal vein thrombosis, the most common location of SVT, is frequently diagnosed in liver cirrhosis (pooled incidence 4.6 per 100 patient-years), and liver cirrhosis is a common risk factor for SVT (reported in 24%-28% of SVT patients). In cirrhosis-associated SVT, anticoagulant treatment reduces mortality rates, thrombosis extension, and major bleeding, and increases the rates of recanalization, compared to no treatment. Achieving vessel recanalization improves the prognosis of cirrhotic patients by reducing liver-related complications (such as variceal bleeding, ascites, hepatic encephalopathy). Anticoagulation should be therefore routinely prescribed to cirrhotic patients with acute SVT unless contraindicated by active bleeding associated with hemodynamic impairment or by excessively high bleeding risk. Of note, early treatment is associated with higher probability of achieving vessel recanalization. The standard treatment consists of low-molecular-weight heparin, followed by oral anticoagulants (eg, vitamin K antagonists or direct oral anticoagulants), if not contraindicated by severe liver dysfunction. Cirrhotic patients with SVT should be treated long-term (especially if candidate for liver transplantation) since liver cirrhosis is a persistent risk factor for recurrent thrombosis. In this review, we discuss the management of SVT in patients with liver cirrhosis, with a focus on the anticoagulant treatment in terms of indications, timing, drugs, duration, and particular scenarios, such as gastroesophageal varices and thrombocytopenia.

Natural history of portal vein thrombosis in cirrhosis: A systematic review with meta-analysis

BACKGROUND AND AIM

Progression of liver disease in cirrhosis is associated with an increased incidence of portal vein thrombosis (PVT) in cirrhosis. However, evidence suggests that spontaneous recanalization of PVT may occur even without anti-thrombotic therapy. Thus, the present meta-analysis was conducted to study the natural history of PVT in cirrhosis, facilitating decisions regarding anticoagulation.

METHODS

Three electronic databases were searched from 2000 to August 2022 for studies reporting the outcome of PVT in cirrhotics without anticoagulation. The pooled proportions with their 95% confidence intervals (CIs) were calculated using a random-effect model.

RESULTS

A total of 26 studies (n = 1441) were included in the final analysis. Progression of PVT on follow-up was seen in 22.2% (95% CI 16.1-28.4), while 77.7% (95% CI 71.6-83.9) remained non-progressive (improved or stable). The most common outcome was a stable PVT with a pooled event rate of 44.6% (95% CI 34.4-54.7). The pooled rates of regression and complete recanalization of PVT in cirrhotics were 29.3% (95% CI 20.9-37.7) and 10.4% (95% CI 5.0-15.8), respectively. On follow-up after improvement, pooled recurrence rate of PVT was 24.0% (95% CI 14.7-33.4). MELD score, and presence of ascites had a negative association, while a longer follow-up duration had positive association with PVT regression.

CONCLUSION

Approximately 25% of the cases of PVT in cirrhosis are progressive, 30% cases improve, and 45% remain stable. Future studies are needed to analyze the predictors of spontaneous regression.

Global research on portal vein thrombosis and liver transplantation: A bibliometric and visualized study

In recent years, the association between portal vein thrombosis and liver transplantation has extensive attention from physicians worldwide. However, there is no available literature on bibliometric analysis in this research area. Herein, we aimed to conduct a bibliometric analysis to identify the hotspots and frontiers of research related to portal vein thrombosis and liver transplantation. Documents published between 2002 and 2022 were retrieved and downloaded from the Web of Science Core Collection database. VOSviewer was utilized to generate a visualization network map of authors, nations, institutions, journals, and keyword co-occurrence/clustering. Additionaly, CiteSpace was used to analyze the keywords with the strongest bursts. A total of 1272 articles and reviews were extracted from the database. The author Marco Senzolo published the largest number of papers. The United States was the most prolific country, and Hope-Bochon (France) was the top productive institution. Liver Transplantation was the most prolific journal in the field. The most commonly identified keywords in the study were cirrhosis, risk factors, portal vein thrombosis, and management, as revealed by the keyword co-occurrence analysis. It is suggested that patients with cirrhosis, portal vein thrombosis prevention, and management measures for portal vein thrombosis have been prominet topics in recent years. Furthermore, an analysis of keywords with the strongest citation bursts highlighted pediatric liver transplantation, direct oral anticoagulants, and nonalcoholic fatty liver disease as current research trends. Research in portal vein thrombosis and liver transplantation exhibits a general upward trend. The latest hot topics within this area of study involve pediatric patients and nonalcoholic fatty liver disease.

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.

The Efficacy and Safety of Anticoagulants in the Treatment of Cirrhotic Portal Vein Thrombosis: A Systematic Review and Meta-Analysis

Objective

To evaluate the efficacy and safety of anticoagulant therapy in patients with cirrhotic PVT, and compare differences in efficacy and safety among different anticoagulants.

Methods

We comprehensively searched Pubmed, Cochrane Library, EMBASE, and ClinicalTrials.gov from inception to April 2022 for studies using anticoagulants for cirrhotic PVT. Meta-analysis was performed to calculate odds ratios (ORs) with 95% confidence intervals (CIs).

Results

3 RCTs and 14 cohort studies involving 1270 patients were included. Anticoagulant therapy can increase the recanalization rate compared with non-anticoagulation therapy (OR 4.44, 95% CI 3.11-6.32, I² = 2.5%) and can decrease the extension rate of cirrhotic PVT (OR 0.33, 95% CI 0.18-0.62, I² = 41.0%), without increasing the incidence of total bleeding (OR 1.21, 95% CI 0.75-1.97, I² = 9.8%), major bleeding (OR 0.98, 95% CI 0.49-1.95, I² = 19.7%), and variceal bleeding (OR 0.35, 95% CI 0.12-1.01, I² = 39.9%). Subgroup analysis showed that VKA, LMWH, and DOACs could increase the recanalization rate of PVT and were not associated with the risk of bleeding. Studies that compared direct oral anticoagulants (DOACs) with warfarin directly showed that the recanalization rate of PVT in the DOACs group might be higher than that in the warfarin group (OR 30.99, 95% CI 7.39-129.87, I² = 0.0%), and there was no difference in the rate of total bleeding (OR 0.30, 95% CI 0.01-8.65, I² = 79.6%).

Conclusions

Anticoagulants are safe and effective in patients with cirrhotic PVT. The rate of PVT recanalization associated with DOACs may be higher than warfarin.