Incidence and Recurrence of Portal Vein Thrombosis in Cirrhotic Patients

Role of contrast-enhanced ultrasound for differentiation of benign vs. malignant portal vein thrombosis in hepatocellular carcinoma - A systematic review a meta-analysis

Introduction/Purpose

Patients with cirrhosis and hepatocellular carcinoma (HCC) can develop both benign and malignant portal vein thrombosis (PVT). Characterising the nature of PVT is important for planning an optimal therapeutic strategy. In the absence of typical findings or contraindications to computed tomography (CT) or magnetic resonance imaging (MRI), contrast-enhanced ultrasound (CEUS) could help in this differentiation. The present meta-analysis aimed to evaluate the performance of CEUS for characterising PVT in patients with HCC.

Methods

Electronic databases of PubMed, Embase and Scopus were searched from inception to 31 December 2022 for studies analysing the role of CEUS in the differentiation of benign and malignant PVT in HCC. Using the bivariate random effect model, pooled sensitivity and specificity were calculated, and the summary receiver operating characteristic (sROC) curve was plotted.

Results

A total of 12 studies with data from 712 patients were included in the meta-analysis. The pooled sensitivity and specificity of CEUS for the diagnosis of tumour in vein were 97.0% (95% CI: 93.0-98.7) and 96.8% (95% CI: 92.1-98.7), respectively, without significant heterogeneity. A sROC curve was plotted, and the area under the receiver operating characteristic was 0.99 (95% CI: 0.98-1.00). Despite the presence of publication bias, sensitivity analysis did not show any change in sensitivity and specificity.

Discussion

Our meta-analysis summarises the accuracy data from 12 studies, including >700 subjects. Contrast-enhanced ultrasound had excellent diagnostic accuracy with pooled sensitivity and specificity of 97.5% (95% CI: 93.5-99.1) and 98.2% (95% CI: 91.5-99.6), respectively, without any significant heterogeneity. Additionally, the pooled positive LR, negative LR and DOR were 54.6 (95% CI: 11.1-25.6), 0.02 (0.01-0.07) and 2186.8 (318.3-15022.2), respectively. A positive result increases the pretest probability of malignant PVT from 50% to 98%, whereas a negative result decreases it from 50% to 2%. Most of the studies included in our meta-analysis used identical techniques and 6-12-month follow-up scans to check for thrombus progression or regression. Our analysis showed no significant heterogeneity in the studies, and area under receiver operating characteristic curve (AUROC) with 95% CI was 1.00 (95% CI: 0.99-1.00). This critical meta-analysis thus propels CEUS to the forefront for differentiating benign from tumoural PVT and suggests routinely using CEUS in patients presenting with HCC and evidence of thrombus on greyscale ultrasound.

Conclusion

Contrast-enhanced ultrasound is an effective diagnostic modality differentiation of benign and malignant PVT in patients with HCC and can be an alternative modality to CT or MRI. Further studies are required to study the role of CEUS as initial diagnostic modality for the characterisation of PVT in HCC.

Role of nonneoplastic PVT in the natural history of patients with cirrhosis and first diagnosis of HCC

BACKGROUND AND AIMS

HCC can increase the risk of nonneoplastic PVT in cirrhosis. However, the natural history of PVT and its prognostic role in HCC patients are unknown.

APPROACH AND RESULTS

Consecutive HCC patients with cirrhosis undergoing laparoscopic ablation were retrospectively evaluated and followed up to 36 months. HCC and PVT characteristics and evolution were reviewed. PVT was categorized according to lumen occupancy (≤50%, >50% <100%, and = 100%) and extension to other veins. The evolution of thrombosis was considered at 1 year from diagnosis. Variables associated with the presence of PVT and evolution patterns were analyzed, as well as their impact on survival. In all, 750 patients were included, 88 of whom had PVT. On multivariate analysis, the occurrence of PVT at HCC diagnosis was associated with pretreatment total tumor volume ( p < 0.001) and clinically significant portal hypertension ( p = 0.005). During the follow-up, 46 de novo PVT occurred, 27/46 (58.7%) in the presence of a viable tumor. Among 115 PVT diagnosed in the presence of HCC, 83 had available radiological follow-up, and 22 were anticoagulated. The "complete/progressive" evolution pattern was associated with nonresponse to HCC treatment in non-anticoagulated patients. The presence of PVT was independently associated with lower overall survival, particularly when progressive or occlusive ( p < 0.001). A higher competing risk of death emerged for "complete and progressive" PVT, both for HCC-related ( p < 0.001) and non-HCC-related ( p = 0.002) death.

CONCLUSIONS

HCC represents an independent risk factor for the occurrence and progression of PVT in cirrhosis. Since progressive and occlusive PVT seems to be an independent factor associated with mortality, screening and prompt treatment of this complication should be considered.

Intestinal Obstruction as Initial Presentation of Idiopathic Portal and Mesenteric Venous Thrombosis: Diagnosis, Management, and Literature Review

It is quite common for portal vein thrombosis to occur in subjects who present predisposing conditions such as cirrhosis, hepatobiliary malignancies, infectious or inflammatory abdominal diseases, or hematologic disorders. The incidence of idiopathic portal vein thrombosis in non-cirrhotic patients remains low, and despite the intensive workup that is performed in these cases, in up to 25% of cases, there is no identifiable cause. If portal vein thrombosis is untreated, complications arise and include portal hypertension, cavernous transformation of the portal vein, gastroesophageal and even small intestinal varices, septic thrombosis, or intestinal ischemia. However, intestinal ischemia develops as a consequence of arterial thrombosis or embolism, and the thrombosis of the mesenteric vein accounts for about 10% of cases of intestinal ischemia. Although acute superior mesenteric vein thrombosis can cause acute intestinal ischemia, its chronic form is less likely to cause acute intestinal ischemia, considering the possibility of developing collateral drainage. Ileus due to mesenteric venous thrombosis is rare, and only a small number of cases have been reported to date. Most patients experience a distinct episode of acute abdominal pain due to ischemia, and in the second phase, they develop an obstruction/ileus. Acute superior mesenteric venous thrombosis is a rare condition that is still associated with a high mortality rate. The management of such cases of superior mesenteric venous thrombosis is clinically challenging due to their insidious onset and rapid development. A prompt and accurate diagnosis followed by a timely surgical treatment is important to save patient lives, improve the patient survival rate, and conserve as much of the patient's bowel as possible, thus leading to fewer sequelae.

Comparative effectiveness of warfarin in cirrhotic patients with non-symptomatic portal vein thrombosis: a multicenter, randomized controlled trial

The effectiveness and risks of anticoagulant therapy in cirrhotic patients with non-symptomatic portal vein thrombosis (PVT) remain unclear. We conducted a multicenter, Zelen-designed randomized controlled trial to determine the effectiveness of warfarin in cirrhotic patients with non-symptomatic PVT during a one-year follow-up. In brief, 64 patients were 1:1 randomly divided into the anticoagulation group or the untreated group. The probability of recanalization was significantly higher in the anticoagulation group than those untreated in both ITT analysis (71.9% vs 34.4%, p = 0.004) and PP analysis (76.7% vs 32.4%, p < 0.001). Anticoagulation treatment was the independent predictor of recanalization (HR 2.776, 95%CI 1.307-5.893, p = 0.008). The risk of bleeding events and mortality were not significantly different. A significantly higher incidence of ascites aggravation was observed in the untreated group (3.3% vs 26.5%, p = 0.015). In conclusion, warfarin was proved to be an effective and safe as an anticoagulation therapy for treating non-symptomatic PVT in cirrhotic patients.

Potential contribution of the gut microbiota to the development of portal vein thrombosis in liver cirrhosis

Background

Portal vein thrombosis (PVT) is a serious complication of liver cirrhosis (LC) and is closely related to gut homeostasis. The study aimed to investigate the composition of gut microbiota and its putative role in PVT development in LC.

Methods

33 patients with LC admitted between January 2022 and December 2022 were enrolled in this study. Based on imaging findings, they were categorized into LC without PVT (n = 21) and LC with PVT (n = 12) groups. Fecal samples were collected from each participant and underwent 16S rDNA sequencing.

Results

D-Dimer and platelet elevations were the main clinical features of LC with PVT. The alpha and beta diversity of the gut microbiota in LC with PVT group was found to be significantly higher compared to the control group. The structure of the gut microbiota was significantly different between the two groups. Based on LEfSe data, the genera Akkermansia, Eubacterium hallii group, Fusicatenibacter, and Anaerostipes were enriched in the LC with PVT, while Enterococcus, Weissella, Bacteroides, and Subdoligranulum were enriched in those of the LC subjects. Changes in microbiota structure result in significant differences in gut microbiota metabolism between the two groups. Altered levels of the microbiota genera were shown to be correlated with coagulation factor parameters. In animal experiments, the addition of Bacteroides reversed the CCl4-induced PVT.

Conclusion

Liver cirrhosis with PVT led to a disorder in the gut microbiota, which was characterized by an increase in pathogenic bacteria and a decrease in beneficial bacteria. Furthermore, modulating the gut microbiota, especially Bacteroides, may be a promising therapeutic approach to reduce the progression of PVT in LC.

Interventional Approach to Portal Vein Thrombosis and Liver Transplantation: State of the Art

Porto-mesenteric vein thrombosis (PVT) is a well-recognized but uncommon disease entity in patients with and without cirrhosis. Given the complexity of these patients, there are many differing treatment algorithms depending on the individual circumstances of a given patient. The focus of this review is primarily patients with cirrhosis, with an emphasis on liver transplantation considerations. The presence of cirrhosis substantially affects work-up, prognosis, and management of these patients and will substantially affect the patient treatment and have additional implications for prognosis and long-term outcomes. Here, we review the incidence of portal vein thrombosis in known cirrhotic patients, medical and interventional treatment options that are currently used, and, in particular, how to approach cirrhotic patients with PVT who are awaiting liver transplantation.

Gut dysbiosis, endotoxemia and clotting activation: A dangerous trio for portal vein thrombosis in cirrhosis

Liver cirrhosis (LC) is associated with portal venous thrombosis (PVT) in roughly 20% of cirrhotic patients but the underlying mechanism is still unclear. Low-grade endotoxemia by lipopolysaccharides (LPS), a component of outer gut microbiota membrane, is detectable in the portal circulation of LC and could predispose to PVT. LPS may translocate into systemic circulation upon microbiota dysbiosis-induced gut barrier dysfunction, that is a prerequisite for enhanced gut permeability and ensuing endotoxemia. Experimental and clinical studies provided evidence that LPS behaves a pro-thrombotic molecule so promoting clotting and platelet activation. Experiments conducted in the portal circulation of cirrhotic patients showed the existence of LPS-related enhanced thrombin generation as well as endothelial dysfunction, venous stasis, and platelet activation. The review will analyze 1) the pro-thrombotic role of endotoxemia in the context of LC 2) the biological plausibility linking endotoxemia with PVT and 3) the potentially interventional tools to lower endotoxemia and eventually hypercoagulation.

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.

Thromboprophylaxis for venous thromboembolism prevention in hospitalized patients with cirrhosis: Guidance from the SSC of the ISTH

Hospital-associated venous thromboembolism (HA-VTE) is a major cause of morbidity and mortality and is internationally recognized as a significant patient safety issue. While cirrhosis was traditionally considered to predispose to bleeding, these patients are also at an increased risk of VTE, with an associated increase in mortality. Hospitalization rates of patients with cirrhosis are increasing, and decisions regarding thromboprophylaxis are complex due to the uncertain balance between thrombosis and bleeding risk. This is further accentuated by derangements of hemostasis in patients with cirrhosis that are often considered contraindications to pharmacological thromboprophylaxis. Due to the strict inclusion and exclusion criteria of seminal studies of VTE risk assessment and thromboprophylaxis, there is limited data to guide decision making in this patient group. This guidance document reviews the incidence and risk factors for HA-VTE in patients with cirrhosis, outlines evidence to inform the use of thromboprophylaxis, and provides pragmatic recommendations on VTE prevention for hospitalized patients with cirrhosis. In brief, in hospitalized patients with cirrhosis: We suggest inclusion of portal vein thrombosis as a distinct clinically important endpoint for future studies. We recommend against the use of thrombocytopenia and/or prolongation of prothrombin time/international normalized ratio as absolute contraindications to anticoagulant thromboprophylaxis. We suggest anticoagulant thromboprophylaxis in line with local protocols and suggest low molecular weight heparin (LMWH) or fondaparinux over unfractionated heparin (UFH). In renal impairment, we suggest LMWH over UFH. For critically ill patients, we suggest case-by-case consideration of thromboprophylaxis. We recommend research to refine VTE risk stratification, and to establish the optimal dosing and duration of thromboprophylaxis.

Impact of Asymptomatic Superior Mesenteric Vein Thrombosis on the Outcomes of Patients with Liver Cirrhosis

BACKGROUND

 The impact of asymptomatic superior mesenteric vein (SMV) thrombosis on the outcomes of cirrhotic patients remains uncertain.

METHODS

 Nonmalignant cirrhotic patients who were consecutively admitted between December 2014 and September 2021 and underwent contrast-enhanced computed tomography/magnetic resonance imaging scans were screened. Portal venous system thrombosis (PVST) was identified. Death and hepatic decompensation were the outcomes of interest. Nelson-Aalen cumulative risk curve analysis and competing risk regression analysis were performed to evaluate the impact of asymptomatic SMV thrombosis and portal vein thrombosis (PVT) on the outcomes.

RESULTS

 Overall, 475 patients were included, of whom 67 (14.1%) had asymptomatic SMV thrombosis, 95 (20%) had PVT, and 344 (72.4%) did not have any PVST. Nelson-Aalen cumulative risk curve analyses showed that the cumulative incidences of death (p = 0.653) and hepatic decompensation (p = 0.630) were not significantly different between patients with asymptomatic SMV thrombosis and those without PVST, but the cumulative incidences of death (p = 0.021) and hepatic decompensation (p = 0.004) were significantly higher in patients with PVT than those without PVST. Competing risk regression analyses demonstrated that asymptomatic SMV thrombosis was not a significant risk factor for death (subdistribution hazard ratio [sHR] = 0.89, p = 0.65) or hepatic decompensation (sHR = 1.09, p = 0.63), but PVT was a significant risk factor for death (sHR = 1.56, p = 0.02) and hepatic decompensation (sHR = 1.50, p = 0.006). These statistical results remained in competing risk regression analyses after adjusting for age, sex, and Child-Pugh score.

CONCLUSIONS

 Asymptomatic SMV thrombosis may not influence the outcomes of cirrhotic patients. The timing of intervention for asymptomatic SMV thrombosis in liver cirrhosis should be further explored.

Rebalanced hemostasis in liver disease: a misunderstood coagulopathy

The combination of frequently abnormal hemostatic markers and catastrophic bleeding as seen with variceal hemorrhage has contributed to the longstanding misperception that chronic liver disease (CLD) constitutes a bleeding diathesis. Laboratory studies of hemostasis in liver disease consistently challenge this with global coagulation assays incorporating activation of the protein C pathway demonstrating rebalanced hemostasis. It is now recognized that bleeding in CLD is predominantly secondary to portal hypertension (rather than a coagulopathy) and additionally that these patients are at increased risk of venous thrombosis, particularly in the portal venous system. This narrative review describes the current understanding of hemostasis in liver disease, as well as the periprocedural management of hemostasis and anticoagulation for management of venous thromboembolism in patients with CLD.

Prevalence of bleeding and thrombosis in critically ill patients with chronic liver disease

INTRODUCTION

Haemorrhage and venous thromboembolism (VTE) are recognised complications of chronic liver disease (CLD), but their prevalence and risk factors in critically ill patients is uncertain.

PATIENTS AND METHODS

We studied a retrospective cohort of patients with CLD non-electively admitted to a specialist intensive care unit determining the prevalence and timing of major bleeding and VTE (early, present on admission/diagnosed within 48h; later diagnosed >48h post ICU admission). Associations with baseline clinical and laboratory characteristics, multi-organ failure (MOF), blood product administration and mortality were explored. Odds ratios (OR) and 95% CIs were calculated using logistic regression.

RESULTS

Of 623 patients with median age 52, bleeding (>48 hours after admission) occurred in 87 (14%) patients. Bleeding was associated with greater illness severity and increased mortality. Gastrointestinal bleeding accounted for 72% of events, secondary to portal hypertension in >90%. Procedure-related bleeding was uncommon. VTE occurred in 125 (20%) patients: Early VTE in 80 (13%) and involving the portal vein (PVT) in 85%. Later VTE affected 45 (7.2%) patients. Hepatocellular Carcinoma (HCC) and non-alcoholic liver disease were independently associated with early VTE (OR 2.79, (95% CI 1.5 -5.2) and 2.32, (1.4 -3.9) respectively), and HCC, sepsis and cryoprecipitate use with late VTE (OR 2.45, (1.11-5.43), 2.26 (1.2-4.3) and 2.60 (1.3-5.1).

CONCLUSION

VTE was prevalent on admission to critical care and less commonly developed later. Bleeding was associated with MOF and increased mortality. Severe MOF was not associated with an increased rate of VTE which was linked with HCC, and specific etiologies of CLD.

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.

The Impact of Portal Vein Thrombosis on the Prognosis of Patients With Cirrhosis: A Retrospective Propensity-Score Matched Study

Objectives: To investigate the impact of portal vein thrombosis (PVT) on cirrhosis decompensation and survival of cirrhosis.

Methods: In this retrospective observational study between January 2012 and August 2020, 117 patients with cirrhotic PVT and 125 patients with cirrhosis were included. Propensity score matching (PSM) was applied to reduce the bias. The clinical characteristics of non-tumoral PVT in cirrhosis and its influence on cirrhosis decompensation and survival were analyzed.

Results: The median follow-up for the PVT group was 15 (8.0–23.0) months and for the non-thrombosis group 14 (8.0–23.5) months. The presence of PVT was related with esophageal varices, higher Child-Pugh score and MELD score (P < 0.05). Most PVTs were partial (106/117). Non-occlusive PVT disappeared on later examinations in 32/106 patients (30.19%), of which six patients reappeared. All the 11 patients with occlusive PVT remained occlusive, among which five patients (45.45%) developed portal cavernoma. There was no significant correlation between PVT and decompensation or survival before or after PSM. Multivariate analysis identified only Child-Pugh score (HR = 2.210, 95% CI: 1.332–3.667) and serum sodium level (HR = 0.818, 95% CI: 0.717–0.933) as independent factors for death.

Conclusion: Though PVT is associated with greater Child-Pugh score and MELD score, it has no significant impact on the progression of cirrhosis.

Treatment of direct oral anticoagulants in patients with liver cirrhosis and portal vein thrombosis

Although patients with cirrhosis are known to be in a state of “rebalance” in that pro- and anticoagulant factors increase the risk for both bleeding and thrombosis, the prevalence of portal vein thrombosis (PVT) in patients with cirrhosis can be up to 26%. Therefore, physicians should consider anticoagulation for the prevention and management of PVT in patients with cirrhosis who are at high risk of PVT. Vitamin K antagonist or low molecular weight heparin is suggested as the standard treatment for PVT in cirrhosis. With the advent of new direct-acting oral anticoagulants (DOACs), there is a paradigm shift of switching to DOACs for the treatment of PVT in patients with cirrhosis. However, the safety and efficacy of DOACs in the treatment of PVT was not well-known in patients with cirrhosis. Therefore, this review focused on the current knowledge about the efficacy, safety concerns, and hepatic metabolism of DOACs in patients with cirrhosis and PVT.

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.

Clostridium Difficile and COVID-19: Novel Risk Factors for Acute Portal Vein Thrombosis

The COVID-19 pandemic has created an unprecedented global health care crisis. COVID-19 patients are found to have increased thrombotic risk. Despite being on prophylactic anticoagulation, many develop serious arterial and venous thromboembolic events. Emerging reports indicate COVID-19 may be considered a novel risk factor for portal vein thrombosis. Although, intra-abdominal infections are identified as risk factors, clostridium difficile colitis has not been typically seen as a risk factor for PVT. We report a case of an elderly female with a recent diagnosis of COVID-19 and no prior history of cirrhosis or malignancy who presented with diarrhea due to clostridium difficile infection. She developed sudden onset severe abdominal pain during the course of hospitalization. Acute portal vein thrombosis was identified on CT imaging of the abdomen, and she improved well with therapeutic anticoagulation. Acute portal vein thrombosis usually results from a combination of local and systemic prothrombotic risk factors. The combination of local infection by clostridium difficile and COVID-19 coagulopathy led to development of portal vein thrombosis in our patient. To the best of our knowledge, this is the first case of portal vein thrombosis reported in a patient with clostridium difficile infection in the setting of COVID-19 coagulopathy. During the current pandemic, clinicians should strongly consider abdominal imaging in patients presenting with abdominal pain due to clostridium difficile infection in the setting of COVID-19 to rule out complications such as portal vein thrombosis. Early diagnosis and treatment of portal vein thrombosis prevent complications of portal hypertension and intestinal infarctions.

Anticoagulation in patients with advanced liver disease: an open issue

Liver disease has been long considered as a risk factor for bleeding for the presence of prolongation of global tests of clotting activation and low platelet count. For this reason, the use of anticoagulants in patients with liver disease and an indication to anticoagulation, such as atrial fibrillation of venous thrombosis, has been poorly considered. Furthermore, recent studies underscored the fact that patients with chronic liver disease may experience thrombosis in portal as well as systemic circulation and treatment with anticoagulants should be considered. The introduction of direct oral anticoagulants has increased therapeutic options for thromboprophylaxis; however, evidence on their safety and efficacy in specific populations, such as patients with liver disease, is still scarce and needs further investigation. Thus, atrial fibrillation patients with coexistent liver disease have been excluded from clinical trials with direct oral anticoagulants. Here, we provide an overview on mechanisms of thrombosis in patients with advanced chronic liver disease and a summary of evidence on the use of oral anticoagulants in patients with liver disease and portal vein thrombosis or atrial fibrillation.

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.

Venous thrombosis of the liver: current and emerging concepts in management

Venous thrombosis within the hepatic vasculature is associated with a distinct array of risk factors, characteristics, and potential complication. As such, it entails unique management considerations and strategies relative to the more common categories of venous thromboembolic disease. Although broadly divided into thrombosis of the afferent vasculature (the portal venous system) and efferent vasculature (the hepatic venous system), presentations and management strategies within these groupings are heterogeneous. Management decisions are influenced by a variety of factors including the chronicity, extent, and etiology of thrombosis. In this review we examine both portal vein thrombosis and hepatic vein thrombosis (and the associated Budd-Chiari Syndrome). We consider those factors which most impact presentation and most influence treatment. In so doing, we see how the particulars of specific cases introduce nuance into clinical decisions. At the same time we attempt to organize our understanding of such cases to help facilitate a more systematic approach. Critically, we must recognize that although increasing evidence is emerging to help guide our management strategies, the available data remain limited and largely retrospective. Indeed, current paradigms are based largely on observational experiences and expert consensus. As new and more rigorous studies emerge, treatment strategies are likely to be continually refined, and paradigm shifts are sure to occur.

Investigation of Thrombosis Volume, Anticoagulants, and Recurrence Factors in Portal Vein Thrombosis with Cirrhosis

This retrospective study investigated factors influencing the portal vein thrombosis (PVT) volume and recurrence in 52 cirrhosis patients with PVT from November 2008 to September 2018. All patients were treated with danaparoid sodium with or without additional antithrombin III. Blood platelet counts significantly correlated with the PVT volume (r² = 0.17; P < 0.01). Computed tomography confirmed recurrence as PVT aggravation was reported in 43 patients, with ≥50% PVT volume reduction following anticoagulation therapy. In 43 patients, recurrence significantly correlated with the pretreatment PVT volume (P = 0.019). Factors influencing recurrence included a Child-Pugh score >8 (P = 0.049) and fibrosis index ≤7.0 based on four factors (FIB-4) (P = 0.048). Moreover, the relationship between recurrence and correlating factors showed that 15 patients who received warfarin experienced recurrence more often when Child-Pugh scores were >8 (P = 0.023), regardless of maintenance treatment. For patients who did not receive warfarin, a PVT volume ≥3.0 mL significantly influenced recurrence (P = 0.039). Therefore, the platelet count influences the PVT volume. The pretreatment PVT volume correlated with recurrence after anticoagulation therapy. According to the Kaplan-Meier curve, risk factors for PVT recurrence after anticoagulation therapy included Child-Pugh scores >8 and FIB-4 ≤7.0. Therefore, the FIB-4 is a unique factor that shows trends opposing other liver function markers.

Incidence of Bleeding and Thrombosis in Patients with Liver Disease

Historically, liver disease has been associated with a bleeding tendency. Global hemostatic assays have demonstrated that hemostasis is overall rebalanced, in both acute liver failure and chronic liver disease. It is now recognized that many bleeding events in chronic liver disease are mediated by portal hypertension rather than an underlying hemostatic defect. This is acknowledged in recent guidelines, which recommend against coagulation testing prior to low risk procedures in this patient group, with avoidance also of attempts at correction of prolonged coagulation times. Over time, the incidence of bleeding events has decreased in both chronic liver disease and acute liver failure, with improved supportive care, targeted treatments for underlying cause of liver disease, and the advent of liver transplantation. Concurrently, there has been increased recognition of the risk of thrombosis in chronic liver disease, with a predilection for the splanchnic vasculature. This review describes the incidence of bleeding and thrombosis in chronic liver disease and acute liver failure, including the periprocedural and liver transplantation setting.

Splanchnic Vein Thrombosis: Current Perspectives

Splanchnic vein thrombosis (SVT) including portal, mesenteric, splenic vein thrombosis and the Budd-Chiari syndrome, is a manifestation of unusual site venous thromboembolism. SVT presents with a lower incidence than deep vein thrombosis of the lower limbs and pulmonary embolism, with portal vein thrombosis and Budd-Chiari syndrome being respectively the most and the least common presentations of SVT. SVT is classified as provoked if secondary to a local or systemic risk factor, or unprovoked if the causative trigger cannot be identified. Diagnostic evaluation is often affected by the lack of specificity of clinical manifestations: the presence of one or more risk factors in a patient with a high clinical suspicion may suggest the execution of diagnostic tests. Doppler ultrasonography represents the first line diagnostic tool because of its accuracy and wide availability. Further investigations, such as computed tomography and magnetic resonance angiography, should be executed in case of suspected thrombosis of the mesenteric veins, suspicion of SVT-related complications, or to complete information after Doppler ultrasonography. Once SVT diagnosis is established, a careful patient evaluation should be performed in order to assess the risks and benefits of the anticoagulant therapy and to drive the optimal treatment intensity. Due to the low quality and large heterogeneity of published data, guidance documents and expert opinion could direct therapeutic decision, suggesting which patients to treat, which anticoagulant to use and the duration of treatment.

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.