Prevalence of spontaneous hepatofugal portal flow in liver cirrhosis. Clinical and endoscopic correlation in 228 patients

Hepatofugal portal flow is highly predictive of acute-on-chronic liver failure: A new hemodynamic patho-physiological hypothesis

BACKGROUND AND AIMS

Acute-on-chronic liver failure (ACLF) is a severe complication of advanced liver disease. A significant number of ACLF patients have not clear precipitating factors. The aim of the study was to investigate the role of alterations in porto-hepatic hemodynamics, especially non-forward portal flow (NFPF), in ACLF and liver-related mortality.

METHODS

233 cirrhotic patients were included in the study with a median follow-up of 24 months. Color-Doppler ultrasound was used to assess portal vein patency, flow direction and significant porto-systemic collaterals (>8 mm). Patients with active cancer, both at baseline and during follow-up and severe non liver-related comorbidities were excluded. ACLF and liver-related mortality were recorded during follow-up.

RESULTS

Fifty-six patients (24%) developed ACLF; 24 (10,3%) had baseline NFPF. In survival analysis, NFPF, but not portal vein thrombosis, was independently associated with ACLF development (HR 2.85 95% C.I. [1.49-5.42], p = 0.001) and liver-related mortality (HR 2.24 95% C.I. [1.16-4.28], p = 0.015), even after adjustment for liver disease severity scores, age and etiology of liver disease.

CONCLUSION

NFPF is independently associated with ACLF development and liver-related mortality, regardless of etiology, severity disease scores and portal vein thrombosis. Although there is no specific measure to reverse NFPF, patients with NFPF should receive prompt intensive management and urgent prioritization for liver transplantation.

CLINICAL TRIAL NUMBER

2730 CESC.

Portal Hypertension in Non-alcoholic Fatty Liver Disease in the Era of Non-invasive Assessment

Non-alcoholic fatty liver disease (NAFLD) is one of the emerging global health problems due to an increase of burden worldwide. It has been known that NAFLD is strongly associated with metabolic syndrome. The progression of NAFLD is a complex and multifactorial mechanism. Portal hypertension is still the main key in liver disease progression management. In NAFLD, portal hypertension might occur in the non-cirrhotic condition. Hepatic vein pressure gradient measurement has been considered as the gold standard for portal pressure assessment; however, due to its invasiveness and the need for a high-expertise centre, it is considered a non-practical measurement tool in clinical practice. Many other non-invasive parameters have been developed to replace the invasive measurement; however, there are still some limitations with regard to the technical issue, patient’s condition, and its accuracy in the different stages of the disease. Therefore, the authors review portal hypertension related to the clinical course of NAFLD, and the development of portal pressure evaluation in patients with NAFLD.

Influence of portal vein occlusion on portal flow and liver elasticity in an animal model

Hepatic fibrosis causes an increase in liver stiffness, a parameter measured by elastography and widely used as a diagnosis method. The concomitant presence of portal vein thrombosis (PVT) implies a change in hepatic portal inflow that could also affect liver elasticity. The main objective of this study is to determine the extent to which the presence of portal occlusion can affect the mechanical properties of the liver and potentially lead to misdiagnosis of fibrosis and hepatic cirrhosis by elastography. Portal vein occlusion was generated by insertion and inflation of a balloon catheter in the portal vein of four swines. The portal flow parameters peak flow (PF) and peak velocity magnitude (PVM) and liver mechanical properties (shear modulus) were then investigated using 4D-flow MRI and MR elastography, respectively, for progressive obstructions of the portal vein. Experimental results indicate that the reduction of the intrahepatic venous blood flow (PF/PVM decreases of 29.3%/8.5%, 51.0%/32.3% and 83.3%/53.6%, respectively) measured with 50%, 80% and 100% obstruction of the portal vein section results in a decrease of liver stiffness by 0.8% ± 0.1%, 7.7% ± 0.4% and 12.3% ± 0.9%, respectively. While this vascular mechanism does not have sufficient influence on the elasticity of the liver to modify the diagnosis of severe fibrosis or cirrhosis (F4 METAVIR grade), it may be sufficient to attenuate the increase in stiffness due to moderate fibrosis (F2-F3 METAVIR grades) and consequently lead to false-negative diagnoses with elastography in the presence of PVT.

Impact of spontaneous splenorenal shunt on liver volume and long-term survival of liver cirrhosis

BACKGROUND AND AIM

Spontaneous splenorenal shunt (SSRS) is one of the manifestations of portal hypertension in liver cirrhosis. However, the impact of SSRS on long-term survival of cirrhotic patients remains unclear. We hypothesize that SSRS may worsen liver dysfunction and deteriorate prognosis in liver cirrhosis by decreasing hepatic perfusion.

METHODS

Patients with liver cirrhosis who were admitted to our department between December 2014 and August 2019 and underwent contrast-enhanced computed tomography or magnetic resonance imaging scans were prospectively collected. The maximum diameters of SSRS and portal vein system vessels were retrospectively measured. Liver-to-abdominal area ratio, Child-Pugh, and model for end-stage liver disease scores were calculated.

RESULTS

Overall, 122 cirrhotic patients were included. The prevalence of SSRS was 30.3% (37/122). Median diameter of SSRS was 13.5 mm. Patients with SSRS had significantly thinner diameters of right portal vein (9 mm vs 11.2 mm, P = 0.001) and main portal vein (15.3 mm vs 16.8 mm, P = 0.017) than those without SSRS. Patients with SSRS had significantly lower liver-to-abdominal area ratio score (25.39 vs 31.58, P < 0.001) and higher Child-Pugh (7 vs 6, P = 0.046) and model for end-stage liver disease (12.17 vs 9.79, P < 0.006) scores than those without SSRS. Patients with SSRS had a significantly lower cumulative survival rate than those without SSRS (P = 0.014). Cox regression analysis also showed that SSRS was a risk factor of death of cirrhotic patients (hazard ratio = 4.161, 95% confidence interval = 1.215-14.255, P = 0.023).

CONCLUSIONS

Spontaneous splenorenal shunt may narrow portal vein diameter and shrink liver volume, thereby worsening liver function and increasing mortality in liver cirrhosis.

Endothelial Damage of the Portal Vein is Associated with Heparin-Like Effect in Advanced Stages of Cirrhosis

Background Portal vein thrombosis (PVT) is the most common thrombotic complication in cirrhosis; however, local risk factors involved in its pathogenesis are still not fully investigated. The aim of the study was to evaluate hemostasis and endothelial damage in the portal vein in patients with cirrhosis and portal hypertension.

Methods Adult cirrhotics undergoing transjugular intrahepatic portosystemic shunt were consecutively enrolled. Rotational thromboelastometry (ROTEM), dosage of total circulating glycosaminoglycans (GAGs), and endotoxemia levels (lipopolysaccharide [LPS]), along with evaluation of endothelial dysfunction by quantification of circulating endothelial microparticles (MPs), were performed on citrated peripheric and portal venous blood samples from each enrolled patient.

Results Forty-five cirrhotics were enrolled. ROTEM analysis revealed the presence of a significant heparin-like effect in portal blood (median ɑ angle NATEM 50° vs. HEPTEM 55°, p = 0.027; median coagulation time NATEM 665 s vs. HEPTEM 585 s, p = 0.006), which was not detected in peripheral blood, and was associated with a higher concentration of circulating GAGs. Even though total annexin V-MP circulating MPs were less concentrated in the splanchnic district, the proportion of MPs of endothelial origin, with respect to annexin V-MP, was significantly increased in the portal district (p = 0.036). LPS concentration was higher in portal (197 pg/mL) compared with peripheral blood (165 pg/mL) (p < 0.001).

Conclusion Evidences of a damage of glycocalyx along with increased concentration of endothelial MPs suggest the presence of a significant endothelial alteration in the portal vein with respect to peripheral veins. Portal site-specific endothelial damage could hamper its antithrombotic properties and may represent an important local risk factor in the pathogenesis of PVT.

Portal Vein Thrombosis in a Patient with Hereditary Antithrombin Deficiency

Portal vein thrombosis (PVT) has been reported in many patients with and without liver cirrhosis. The portal vein is a rare site of thrombosis, and various conditions can predispose an individual to PVT. Among those conditions, hereditary thrombophilia has been increasingly reported recently. We herein report the case of a non-cirrhotic 30-year-old man who developed acute PVT with hereditary antithrombin deficiency. Antithrombin (AT) replacement therapy was required along with heparin. Given our experience with this case, we believe that a screening test for prothrombotic disorders, such as AT deficiency, should be considered in cases of PVT.

A hypothesis on paradoxical privileged portal vein metastasis of hepatocellular carcinoma. Can organ evolution shed light on patterns of human pathology, and vice versa?

Unlike other carcinomas, hepatocellular carcinoma (HCC) metastasizes to distant organs relatively rarely. In contrast, it routinely metastasizes to liver vasculature/liver, affecting portal veins 3-10 times more often than hepatic veins. This portal metastatic predominance is traditionally rationalized within the model of a reverse portal flow, due to accompanying liver cirrhosis. However, this intuitive model is not coherent with facts: 1) reverse portal flow occurs in fewer than 10% of cirrhotic patients, while portal metastasis occurs in 30-100% of HCC cases, and 2) portal vein prevalence of HCC metastasis is also characteristic of HCC in non-cirrhotic livers. Therefore, we must assume that the route for HCC metastatic dissemination is the same as for other carcinomas: systemic dissemination via the draining vessel, i.e., via the hepatic vein. In this light, portal prevalence versus hepatic vein of HCC metastasis appears as a puzzling pattern, particularly in cases when portal HCC metastases have appeared as the sole manifestation of HCC. Considering that other GI carcinomas (colorectal, pancreatic, gastric and small bowel) invariably disseminate via portal vein, but very rarely form portal metastasis, portal prevalence of HCC metastasis appears as a paradox. However, nature does not contradict itself; it is rather our wrong assumptions that create paradoxes. The 'portal paradox' becomes a logical event within the hypothesis that the formation of the unique portal venous system preceded the appearance of liver in evolution of chordates. The analysis suggests that the appearance of the portal venous system, supplying hormones and growth factors of pancreatic family, which includes insulin, glucagon, somatostatin, and pancreatic polypeptide (HGFPF) to midgut diverticulum in the early evolution of chordates (in an Amphioxus-like ancestral animal), promoted differentiation of enterocytes into hepatocytes and their further evolution to the liver of vertebrates. These promotional-dependent interactions are conserved in the vertebrate lineage. I hypothesize that selective homing and proliferation of malignant hepatocytes (i.e., HCC cells) in the portal vein environment are due to a uniquely high concentration of HGFPF in portal blood. HGFPF are also necessary for liver function and renewal and are significantly extracted by hepatocytes from passing blood, creating a concentration gradient of HGFPF between the portal blood and hepatic vein outflow, making post-liver vasculature and remote organs less favorable spaces for HCC growth. It also suggested that the portal vein environment (i.e., HGFPF) promotes the differentiation of more aggressive HCC clones from already-seeded portal metastases, explaining the worse outcome of HCC with the portal metastatic pattern. The analysis also offers new hypothesis on the phylogenetic origin of the hepatic diverticulum of cephalochordates, with certain implications for the modeling of the chordate phylogeny.

Cancer-Associated Thrombosis in Cirrhotic Patients with Hepatocellular Carcinoma

It is common knowledge that cancer patients are more prone to develop venous thromboembolic complications (VTE). It is therefore not surprising that patients with hepatocellular carcinoma (HCC) present with a significant risk of VTE, with the portal vein being the most frequent site (PVT). However, patients with HCC are peculiar as both cancer and liver cirrhosis are conditions that can perturb the hemostatic balance towards a prothrombotic state. Because HCC-related hypercoagulability is not clarified at all, the aim of the present review is to summarize the currently available knowledge on epidemiology and pathogenesis of non-malignant thrombotic complications in patients with liver cirrhosis and HCC. They are at increased risk to develop both PVT and non-splanchnic VTE, indicating that both local and systemic factors can foster the development of site-specific thrombosis. Recent studies have suggested multiple and often interrelated mechanisms through which HCC can tip the hemostatic balance of liver cirrhosis towards hypercoagulability. Described mechanisms include increased fibrinogen concentration/polymerization, thrombocytosis, and release of tissue factor-expressing extracellular vesicles. Currently, there are no specific guidelines on the use of thromboprophylaxis in this unique population. There is the urgent need of prospective studies assessing which patients have the highest prothrombotic profile and would therefore benefit from early thromboprophylaxis.

Prescribing Warfarin to a Patient with Oesophageal Varices—A Case Report and Review of the Literature

We describe the case of a 42-year old man who presented with melaena. He was found to have bleeding varices during endoscopic investigation. Subsequent investigation revealed the aetiology to be a portal vein thrombosis (PVT) due to an underlying pro-coagulable state (Factor V Leiden). He was managed with cautious anticoagulation but suffered a life-threatening upper gastrointestinal bleed that was not amenable to endoscopic treatment or transjugular intrahepatic portosystemic shunting (TIPS). As such, the only therapeutic option involved the pursuit of surgical shunt operations. We review the literature regarding this atypical cause of GI-bleeding and discuss medical and surgical considerations for the management of such patients.

Efficacy and safety of anticoagulation in non-malignant portal vein thrombosis in patients with liver cirrhosis

BACKGROUND AND AIM

Treatment for portal vein thrombosis (PVT) is not well established. Nevertheless, anticoagulation therapy can seemingly be used as first-line therapy. However, there are limited data on the role of this treatment in patients with PVT and cirrhosis. We sought to assess the safety and efficacy of anticoagulation therapy in a series of patients with non-malignant PVT and liver cirrhosis.

METHODS

We analyzed the data of 32 patients with cirrhosis and PVT between March 2009 and September 2015. All patients received anticoagulation treatment. PVT was diagnosed within the context of biannual hepatocellular carcinoma screening in these patients.

RESULTS

Recanalisation was achieved in 23 patients: complete in 17 patients (53.1%) and partial in 6 patients (18.7%). The median time for achieving a complete response was 7 months (95% CI: 6-8). We did not discover any risk factors associated with repermeation (partial or complete). None of the patients presented with thrombosis progression while receiving anticoagulation. Nine patients who achieved complete recanalisation and stopped anticoagulation therapy suffered rethrombosis (52%). There were no differences between the patients who achieved complete or partial recanalisation (35%) and those who did not (33%) in relation to the onset of hepatic events during follow-up. Three patients (9%) presented with bleeding complications: two variceal bleeding episodes and one brain hemorrhage.

CONCLUSIONS

In cirrhotic patients with non-malignant PVT, anticoagulation therapy led to partial or complete recanalisation in 70% of patients, with a broad safety profile. Due to the existing rethrombosis rate, long-term anticoagulation should be considered.

Portal vein thrombosis in cirrhosis: diagnosis, natural history, and therapeutic challenges

Portal vein thrombosis (PVT) is a frequent complication in cirrhosis and its prevalence increases with disease severity. Several factors are involved in the development and progression of PVT. The challenge for the management of PVT is the precise evaluation of the bleeding risk as opposed to life-threatening extension of thrombosis. Nevertheless, the impact on the progression and outcome of liver disease is unclear. A critical evaluation of the available data discloses that treating PVT in cirrhotics is safe and effective. However, there are open issues, such as which anticoagulant could represent a safer therapeutic option, and when and for how long this treatment should be administered to cirrhotic patients with PVT.

Current status of portal vein thrombosis in Japan: Results of a questionnaire survey by the Japan Society for Portal Hypertension

AIM

To investigate the current status of portal vein thrombosis (PVT) in Japan, the Clinical Research Committee of the Japan Society of Portal Hypertension undertook a questionnaire survey.

METHODS

A questionnaire survey of 539 cases of PVT over the previous 10 years was carried out at institutions affiliated with the Board of Trustees of the Japan Society of Portal Hypertension.

RESULTS

The most frequent underlying etiology of PVT was liver cirrhosis in 75.3% of patients. Other causes included inflammatory diseases of the hepatobiliary system and the pancreas, malignant tumors, and hematologic diseases. The most frequent site was the main trunk of the portal vein (MPV) in 70.5%, and complete obstruction of the MPV was present in 11.5%. Among the medications for PVT, danaparoid was given to 45.8%, warfarin to 26.2%, heparin to 17.3%, and anti-thrombin III to 16.9%. Observation of the course was practiced in 22.4%. Factors contributing to therapeutic efficacy were implementation of various medications, thrombi localized to either the right or left portal vein only, non-complete obstruction of the MPV and Child-Pugh class A liver function. A survival analysis showed that the prognosis was favorable with PVT disappearance regardless of treatment.

CONCLUSION

The questionnaire survey showed the current status of PVT in Japan. Any appropriate medication should be given to a patient with PVT when PVT is recognized. It is necessary to compile a large amount of information and reach a consensus on safe and highly effective management of PVT.

Techniques and long-term effects of transjugular intrahepatic portosystemic shunt on liver cirrhosis-related thrombotic total occlusion of main portal vein

Portal vein hypertension (PVH) in liver cirrhosis complicated with portal venous thrombosis (PVT) has been mainly treated with transjugular intrahepatic portosystemic shunt (TIPS). The clinical effects of TIPS have been confirmed, however, no large-scale studies have been focused on technical analyses and a long-term follow-up, especially on thrombotic total occlusion of main portal vein (MPV). To demonstrate critical techniques and clinical outcome of TIPS on liver cirrhosis-related thrombotic total occlusion of MPV, 98 patients diagnosed with liver cirrhosis related thrombotic total occlusion of MPV and treated with TIPS from January 2000 to January 2010 were retrospectively analyzed. Twenty-three (23.5%) patients had MPV (single site) thrombosis, 55 (56.1%) had multiple site-thrombosis (MPV and other), 17 (17.3%) had cavernous transformation of portal vein, and 3 (3.1%) had post-transplant thrombosis. The successful rate of TIPS was 90.7%, without any procedure-related deaths or severe complications. Mean portal pressure was dropped from 33.08 ± 1.38 mmHg preoperatively to 20.18 ± 0.83 mmHg postoperatively (p < 0.001). Collectively, TIPS is safe and effective in treating liver cirrhosis-related thrombotic total occlusion of MPV. This complex procedure requires combination of indirect portography and percutaneous transhepatic portal techniques to increase the rate of success.

Portal vein thrombosis - a primer for the general physician

Portal vein thrombosis (PVT) is thrombosis of the portal -circulation, which may present with varied symptoms. However, increased use of abdominal imaging has noted a large number of incidental PVT. At the same time, PVT may be overlooked in the absence of the characteristic symptoms. More recently, a JAK2 mutation has been recognised as a cause of PVT. Anticoagulation is the mainstay of treatment, but can pose a dilemma because of the associated coagulopathy, the presence of varices and thrombocytopenia.

Impact of portal hemodynamics on Doppler ultrasonography for predicting decompensation and long-term outcomes in patients with cirrhosis

OBJECTIVE

Significance of portal hemodynamics for non-invasive marker of cirrhosis remains unclear. The aim was to determine the value of portal hemodynamics on Doppler ultrasound for predicting decompensation and prognosis in cirrhosis.

METHODS

This retrospective study comprised 236 cirrhotic patients (132 males, 104 females; age 63.7 ± 11.3 years; 110 compensated, 126 decompensated). Clinical data, including Doppler findings, were analyzed with respect to decompensation and prognosis. The median follow-up period was 33.2 months (0.1-95.4).

RESULTS

Fifty-three patients developed clinical decompensation, 13 patients received liver transplantation, and 71 died. Higher model for end-stage liver disease score (p < 0.001) at baseline was the significant factor for the presence of decompensation. Higher alanine transaminase (p = 0.020), lower albumin (p = 0.002) and lower mean velocity in the portal trunk (p = 0.038) were significant factors for developing decompensation (best cut-off value: Alanine transaminase > 31 IU/L, albumin < 3.6 g/dL, and portal trunk < 12.8 cm/s). The cumulative incidence of decompensation was higher in patients with portal trunk < 12.8 cm/s (22.5% at 1 year, 71.2% at 5 years) than those without (6.9% at 1 year, 35.4% at 5 years; p < 0.001). The significant prognostic factors were hepatocellular carcinoma (p = 0.036) and lower albumin (p = 0.008) for compensated patients, and reversed portal flow (p = 0.028), overt ascites (p < 0.001), and higher bilirubin (p < 0.001) for decompensated patients.

CONCLUSION

Portal hemodynamics offer a non-invasive marker for decompensation and prognosis of cirrhosis, suggesting a future direction for practical management.

Pre-transplant portal vein thrombosis is an independent risk factor for graft loss due to hepatic artery thrombosis in liver transplant recipients

BACKGROUND

Hepatic artery thrombosis is an uncommon but catastrophic complication following liver transplantation. We hypothesize that recipients with portal vein thrombosis are at increased risk.

METHODS

Data on all liver transplants in the U.S. during the MELD era through September 2014 were obtained from UNOS. Status one, multivisceral, living donor, re-transplants, pediatric recipients and donation after cardiac death were excluded. Logistic regression models were constructed for hepatic artery thrombosis with resultant graft loss within 90 days of transplantation.

RESULTS

63,182 recipients underwent transplantation; 662 (1.1%) recipients had early hepatic artery thrombosis; of those, 91 (13.8%) had pre-transplant portal vein thrombosis, versus 7.5% with portal vein thrombosis but no hepatic artery thrombosis (p < 0.0001). Portal vein thrombosis was associated with an increased independent risk of hepatic artery thrombosis (OR 2.17, 95% CI 1.71-2.76, p < 0.001) as was donor risk index (OR 2.02, 95% CI 1.65-2.48, p < 0.001). Heparin use at cross clamp, INR, and male donors were all significantly associated with lower risk.

DISCUSSION

Pre-transplant portal vein thrombosis is associated with post-transplant hepatic artery thrombosis independent of other factors. Recipients with portal vein thrombosis might benefit from aggressive coagulation management and careful donor selection. More research is needed to determine causal mechanism.

Radiographical findings in patients with liver cirrhosis and hepatic encephalopathy

Background and aims: Hepatic encephalopathy is a common complication encountered in patients with liver cirrhosis. Hepatic encephalopathy is not reflected in the current liver transplant allocation system. Correlation was sought between hepatic encephalopathy with findings detected on radiographic imaging studies and the patient’s clinical profile.

Methods: A retrospective analysis was conducted of patients with cirrhosis, who presented for liver transplant evaluation in 2009 and 2010. Patients with hepatocellular carcinoma, ejection fraction less than 60% and who had a TIPS (transjugular intrahepatic portosystemic shunting) procedure or who did not complete the evaluation were excluded. Statistical analysis was performed and variables found to be significant on univariate analysis (P < 0.05) were analysed by a multivariate logistic regression model.

Results: A total of 117 patients met the inclusion criteria and were divided into a hepatic encephalopathy group (n = 58) and a control group (n = 59). Univariate analysis found that a smaller portal vein diameter, smaller liver antero-posterior diameter, liver nodularity and use of diuretics or centrally acting medications showed significant correlation with hepatic encephalopathy. This association was confirmed for smaller portal vein, use of diuretics and centrally acting medications in the multivariate analysis.

Conclusion: A decrease in portal vein diameter was associated with increased risk of encephalopathy. Identifying patients with smaller portal vein diameter may warrant screening for encephalopathy by more advanced psychometric testing, and more aggressive control of constipation and other factors that may precipitate encephalopathy.

Liver and spleen stiffness and other noninvasive methods to assess portal hypertension in cirrhotic patients: a review of the literature

Portal hypertension (PH) is one of the most important causes of morbidity and mortality in patients with chronic liver disease. PH measurement is crucial to stage and predict the clinical outcome of liver cirrhosis. Measurement of hepatic vein pressure gradient is considered the gold standard for assessment of the degree of PH; however, it is an invasive method and has not been used widely. Thus, noninvasive methods have been proposed recently. We critically evaluated serum markers, abdominal ultrasonography, and particularly liver and spleen stiffness measurement, which represent the more promising methods to stage PH degree and to assess the presence/absence of esophageal varices (EV). A literature search was carried out on MEDLINE, EMBASE, Web of Science, and Scopus for articles and abstracts. The search terms used included 'liver cirrhosis', 'portal hypertension', 'liver stiffness', 'spleen stiffness', 'ultrasonography', and 'portal hypertension serum biomarker'. The articles cited were selected on the basis of their relevance to the objective of the review. The results of available studies indicate that individually, these methods have a mild accuracy in predicting the presence of EV, and thus they cannot substitute endoscopy to predict EV. When these tests were used in combination, their accuracy increased. In addition to the PH staging, several serum markers and spleen stiffness measurement can predict the clinical outcome of liver cirrhosis with a good accuracy, comparable to that of hepatic vein pressure gradient. In the future, noninvasive methods could be used to select patients requiring further investigations to identify the best tailored clinical management.

Non-contrast-enhanced MR portography and hepatic venography with time-spatial labeling inversion pulses: comparison at 1.5 Tesla and 3 Tesla

Background

A 3 Tesla (3 T) magnetic resonance (MR) scanner is a promising tool for upper abdominal MR angiography. However, there is no report focused on the image quality of non-contrast-enhanced MR portography and hepatic venography at 3 T.

Purpose

To compare and evaluate images of non-contrast-enhanced MR portography and hepatic venography with time-spatial labeling inversion pulses (Time-SLIP) at 1.5 Tesla (1.5 T) and 3 T.

Material and Methods

Twenty-five healthy volunteers were examined using respiratory-triggered three-dimensional balanced steady-state free-precession (bSSFP) with Time-SLIP. For portography, we used one tagging pulse (selective inversion recovery) and one non-selective inversion recovery pulse; for venography, two tagging pulses were used. The relative signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were quantified, and the quality of visualization was evaluated.

Results

The CNRs of the main portal vein, right portal vein, and left portal vein at 3 T were better than at 1.5 T. The image quality scores for the portal branches of segment 4, 5, and 8 were significantly higher at 3 T than at 1.5 T. The CNR of the right hepatic vein (RHV) at 3 T was significantly lower than at 1.5 T. The image quality scores of RHV and the middle hepatic vein were higher at 1.5 T than at 3 T. For RHV visualization, the difference was statistically significant.

Conclusion

Non-contrast-enhanced MR portography with Time-SLIP at 3 T significantly improved visualization of the peripheral branch in healthy volunteers compared with1.5 T. Non-contrast-enhanced MR hepatic venography at 1.5 T was better than at 3 T.

Portal vein thrombosis

Portal vein thrombosis is an important cause of portal hypertension. PVT occurs in association with cirrhosis or as a result of malignant invasion by hepatocellular carcinoma or even in the absence of associated liver disease. With the current research into its genesis, majority now have an underlying prothrombotic state detectable. Endothelial activation and stagnant portal blood flow also contribute to formation of the thrombus. Acute non-cirrhotic PVT, chronic PVT (EHPVO), and portal vein thrombosis in cirrhosis are the three main variants of portal vein thrombosis with varying etiological factors and variability in presentation and management. Procoagulant state should be actively investigated. Anticoagulation is the mainstay of therapy for acute non-cirrhotic PVT, with supporting evidence for its use in cirrhotic population as well. Chronic PVT (EHPVO) on the other hand requires the management of portal hypertension as such and with role for anticoagulation in the setting of underlying prothrombotic state, however data is awaited in those with no underlying prothrombotic states. TIPS and liver transplant may be feasible even in the setting of PVT however proper selection of candidates and type of surgery is warranted. Thrombolysis and thrombectomy have some role. TARE is a new modality for management of HCC with portal vein invasion.

Review article: portal vein obstruction--epidemiology, pathogenesis, natural history, prognosis and treatment

BACKGROUND

Portal vein obstruction may be due to portal vein thrombosis (PVT) or its sequale, the portal cavernoma. PVT is a common complication in liver cirrhosis, however, it may also occur as a primary vascular disorder, in absence of any liver disease.

AIM

To review the current knowledge on nomenclature, etiology, pathophysiology, clinical presentation, diagnostic workup and management of adult patients with obstruction in the portal vein, either as a primary vascular disease in adults, or as a complication of liver cirrhosis.

METHODS

A structured search in PubMed was performed using defined keywords (portal vein obstruction, extra-hepatic portal vein obstruction, PVT and portal cavernoma), including full text articles and abstracts in English language.

RESULTS

Several causes, operating both at local and systemic level, might play an important role in the pathogenesis of PVT. Frequently, more than one risk factor could be identified; however, occasionally no single factor is discernible. Diagnosis of portal vein obstruction depends on clinical presentation, imaging and laboratory investigations. Prompt treatment greatly affects the patient's outcome.

CONCLUSIONS

Portal vein obstruction occurring either due to thrombosis in the portal vein or due to the portal cavernoma, can contribute to significant morbidity and mortality in patients with or without cirrhosis. In recent years our understanding of etio-pathogenesis of portal vein obstruction has evolved tremendously, which has led to significant improvement in treatment outcomes. There are still areas where more studies are needed to better clarify the management issues of portal vein obstruction.

Portal vein thrombosis in cirrhosis

Portal vein thrombosis (PVT) is being increasingly recognized in patients with advanced cirrhosis and in those undergoing liver transplantation. Reduced flow in the portal vein is probably responsible for clotting in the spleno-porto-mesenteric venous system. There is also increasing evidence that hypercoagulability occurs in advanced liver disease and contributes to the risk of PVT. Ultrasound based studies have reported a prevalence of PVT in 10-25% of cirrhotic patients without hepatocellular carcinoma. Partial thrombosis of the portal vein is more common and may not have pathophysiological consequences. However, there is high risk of progression of partial PVT to complete PVT that may cause exacerbation of portal hypertension and progression of liver insufficiency. It is thus, essential to accurately diagnose and stage PVT in patients waiting for transplantation and consider anticoagulation therapy. Therapy with low molecular weight heparin and vitamin K antagonists has been shown to achieve complete and partial recanalization in 33-45% and 15-35% of cases respectively. There are however, no guidelines to help determine the dose and therapeutic efficacy of anticoagulation in patients with cirrhosis. Anticoagulation therapy related bleeding is the most feared complication but it appears that the risk of variceal bleeding is more likely to be dependent on portal pressure rather than solely related to coagulation status. TIPS has also been reported to restore patency of the portal vein. Patients with complete PVT currently do not form an absolute contraindication for liver transplantation. Thrombectomy or thromboendovenectomy is possible in more than 75% of patients followed by anatomical end-to-end portal anastomosis. When patency of the portal vein and/or superior mesenteric vein is not achieved, only non-anatomical techniques (reno-portal anastomosis or cavo-portal hemitransposition) can be performed. These techniques, which do not fully reverse portal hypertension, are associated with higher morbidity and mortality risks in the short term.

Non-contrast-enhanced MR portography and hepatic venography with time-spatial labeling inversion pulses: comparison of imaging with the short tau inversion recovery method and the chemical shift selective method

PURPOSE

To compare and evaluate images of non-contrast enhanced magnetic resonance (MR) portography and hepatic venography acquired with two different fat suppression methods, the chemical shift selective (CHESS) method and short tau inversion recovery (STIR) method.

MATERIALS AND METHODS

Twenty-two healthy volunteers were examined using respiratory-triggered three-dimensional true steady-state free-precession with two time-spatial labeling inversion pulses. The CHESS or STIR methods were used for fat suppression. The relative signal-to-noise ratio and contrast-to-noise ratio (CNR) were quantified, and the quality of visualization was scored.

RESULTS

Image acquisition was successfully conducted in all volunteers. The STIR method significantly improved the CNRs of MR portography and hepatic venography. The image quality scores of main portal vein and right portal vein were higher with the STIR method, but there were no significant differences. The image quality scores of right hepatic vein, middle hepatic vein, and left hepatic vein (LHV) were all higher, and the visualization of LHV was significantly better (p<0.05).

CONCLUSION

The STIR method contributes to further suppression of the background signal and improves visualization of the portal and hepatic veins. The results support using non-contrast-enhanced MR portography and hepatic venography in clinical practice.

Ultrasound in chronic liver disease

Background

With the high prevalence of diffuse liver disease there is a strong clinical need for noninvasive detection and grading of fibrosis and steatosis as well as detection of complications.

Methods

B-mode ultrasound supplemented by portal system Doppler and contrast-enhanced ultrasound are the principal techniques in the assessment of liver parenchyma and portal venous hypertension and in hepatocellular carcinoma surveillance.

Results

Fibrosis can be detected and staged with reasonable accuracy using Transient Elastography and Acoustic Radiation Force Imaging. Newer elastography techniques are emerging that are undergoing validation and may further improve accuracy. Ultrasound grading of hepatic steatosis currently is predominantly qualitative.

Conclusion

A summary of methods including B-mode, Doppler, contrast-enhanced ultrasound and various elastography techniques, and their current performance in assessing the liver, is provided.

Teaching Points

• Diffuse liver disease is becoming more prevalent and there is a strong clinical need for noninvasive detection.

• Portal hypertension can be best diagnosed by demonstrating portosystemic collateral venous flow.

• B-mode US is the principal US technique supplemented by portal system Doppler.

• B-mode US is relied upon in HCC surveillance, and CEUS is useful in the evaluation of possible HCC.

• Fibrosis can be detected and staged with reasonable accuracy using TE and ARFI.

• US detection of steatosis is currently reasonably accurate but grading of severity is of limited accuracy.

Assessment of hemodynamics in a rat model of liver cirrhosis with precancerous lesions using multislice spiral CT perfusion imaging

Rationale and Objectives. To develop an optimal scanning protocol for multislice spiral CT perfusion (CTP) imaging to evaluate hemodynamic changes in liver cirrhosis with diethylnitrosamine- (DEN-) induced precancerous lesions. Materials and Methods. Male Wistar rats were randomly divided into the control group (n = 80) and the precancerous liver cirrhosis group (n = 40). The control group received saline injection and the liver cirrhosis group received 50 mg/kg DEN i.p. twice a week for 12 weeks. All animals underwent plain CT scanning, CTP, and contrast-enhanced CT scanning. Scanning parameters were optimized by adjusting the diatrizoate concentration, the flow rate, and the delivery time. The hemodynamics of both groups was further compared using optimized multislice spiral CTP imaging. Results. High-quality CTP images were obtained with following parameters: 150 kV; 150 mAs; 5 mm thickness, 5 mm interval; pitch, 1; matrix, 512 × 512; and FOV, 9.6 cm. Compared to the control group, the liver cirrhosis group had a significantly increased value of the hepatic arterial fraction and the hepatic artery perfusion (P < 0.05) but significantly decreased hepatic portal perfusion and mean transit time (P < 0.05). Conclusion. Multislice spiral CTP imaging can be used to evaluate the hemodynamic changes in the rat model of liver cirrhosis with precancerous lesions.

Cirrhotic right and left portal veins: how slow do they go? Identification of threshold velocities associated with subsequent development of hepatofugal flow

OBJECTIVE

The purpose of this study was to identify threshold right and left portal vein sonographic velocities that are correlated with subsequent development of hepatofugal flow in the main portal vein (MPV), a marker of portal hypertension.

METHODS

A database containing 6019 Doppler liver ultrasound reports from an academic hospital was parsed using a Visual Basic computer algorithm. Right and left portal vein velocities were identified from 65 patients who developed hepatofugal MPV flow. Patients with a liver transplant or transjugular intrahepatic portosystemic shunt were excluded. Similarly, right and left portal vein velocities were identified from 195 patients free of chronic hepatic disease. The right and left portal vein velocities of these 2 groups were analyzed using a receiver operating characteristic curve to identify threshold velocities with the optimal sensitivity and specificity for patients who will develop hepatofugal flow in the MPV.

RESULTS

A threshold velocity of 11 cm/s in the right portal vein is associated with 81.8% sensitivity and 93.5% specificity in distinguishing patients who develop hepatofugal flow from otherwise healthy control subjects. Likewise, a threshold velocity of 8 cm/s in the left portal vein is associated with a 62.3% sensitivity and a 94.5% specificity.

CONCLUSIONS

A threshold right portal vein velocity of 11 cm/s can be used with high sensitivity and specificity to identify patients who may develop hepatofugal flow in the MPV. A left portal vein velocity less than 8 cm/s is 94.5% specific for the development of hepatofugal flow.

What we should know about portal vein thrombosis in cirrhotic patients: A changing perspective

Portal vein thrombosis (PVT) is one of the most common complications occurring during the natural course of liver cirrhosis. Even though PVT is often asymptomatic, the worsening of liver function, an unexpected episode of gastrointestinal bleeding or ascitic decompensation may be landmarks of PVT development. Beyond these clinical manifestations, it is debated whether PVT really has an impact on liver cirrhosis natural history or rather represents only one of its consequences. Probably PVT development should not only be considered as a matter of impaired blood flow or pro-coagulation tendency. On one hand, PVT seems a consequence of the worsening in portal vein outflow due to the increased hepatic resistance in cirrhotic livers. On the other hand, vascular microthrombosis secondary to necroinflammation may cause liver ischemia and infarction, with loss of hepatic tissue (parenchymal extinction) which is replaced by fibrotic tissue. Therefore, PVT might also be considered as the overt manifestation of the liver fibrosing process evolution and anticoagulant therapy may thus have microscopic indirect effects also on the progression of liver disease. At present, a connection between PVT development and the progression of liver fibrosis/cirrhosis has not yet been demonstrated. Nevertheless, it is not clear if PVT development may worsen cirrhotic patients’ outcome by itself. Some authors tried to assess liver transplant benefit in PVT cirrhotic patients but data are contrasting. In this review, we will try to answer these questions, providing a critical analysis of data reported in literature.

Normal and altered three-dimensional portal venous hemodynamics in patients with liver cirrhosis

PURPOSE

To compare time-resolved three-dimensional (3D) phase-contrast magnetic resonance (MR) imaging with three-directional velocity encoding (flow-sensitive four-dimensional [4D] MR imaging), with Doppler ultrasonography (US) as standard of reference, for investigating alterations in 3D portal venous hemodynamics in patients with liver cirrhosis compared with healthy age-matched control subjects and healthy young volunteers.

MATERIAL & METHODS

This prospective study was approved by the local ethics committee, and written informed consent was obtained from all participants. Three-dimensional portal venous hemodynamics was assessed, employing flow-sensitive 4D MR imaging with a 3-T MR system (spatial resolution, approximately 2 mm(3); temporal resolution, approximately 45 msec) in 20 patients with hepatic cirrhosis, 20 healthy age-matched control subjects, and 21 healthy young volunteers. Flow characteristics were analyzed by using 3D streamlines and time-resolved particle traces. Quantitative analyses were performed by retrospectively evaluating regional peak and mean velocities, flow volume, and vessel area. Doppler US was used as standard of reference. Independent-sample t tests or Wilcoxon-Mann-Whitney tests were applied for comparing each subject group. Paired-sample t tests or Wilcoxon tests were applied when comparing MR imaging and US.

RESULTS

Three-dimensional visualization of portal venous hemodynamics was successful, with complete visualization of the vessels in 18 patients and 35 volunteers, with limitations in the left intrahepatic branches (87%, reader A; 89%, reader B). A moderate but significant correlation was observed between 4D MR imaging and Doppler US in nearly all maximum and mean velocities, flow volumes, and vessel areas (r = 0.24-0.64, P = .001-.044). With MR imaging, significant underestimation was observed of intrahepatic flow velocities and flow volumes, except vessel area, which Doppler US represented as even lower (P < .001 to P = .045). Six patients had collateralization with reopened umbilical vein, while one had flow reversal in the superior mesenteric vein visible at MR imaging only.

CONCLUSION

Flow-sensitive 4D MR imaging may constitute a promising, alternative technique to Doppler US for evaluating hemodynamics in the portal venous system of patients with liver cirrhosis and may be a means of assessing pathologic changes in flow characteristics.

Bleeding and thrombosis in cirrhotic patients: what really matters?

Bleeding complications, particularly in the gastro-intestinal tract, may complicate the clinical course of liver cirrhosis. Coexistence of abnormal global tests exploring the platelet and clotting systems generated the hypothesis that cirrhotic patients have "coagulopathy" predisposing to bleeding complications. Using more sophisticated laboratory methods this hypothesis has been partly confuted as cirrhotic patients actually disclose an ongoing prothrombotic state in the portal and systemic circulation that could predispose to thrombosis. Recent data of the literature support this hypothesis as portal vein thrombosis and peripheral thrombosis are frequent features of cirrhosis. We reviewed the literature data to assess the prevalence of bleeding and thrombotic complication in cirrhosis and the role of clotting activation in precipitating them. Whilst it appears scarcely relevant the interplay between the so called "coagulopathy" and bleeding, the interplay between clotting activation and thrombosis seems to be relevant but needs more accurate investigation in larger study populations.

Association between portal vein color Doppler findings and the severity of disease in cirrhotic patients with portal hypertension

BACKGROUND

Doppler ultrasound is the accepted gold standard for assessing direction of flow in the portal vein (PV). Moreover, it is non-invasive; therefore, it is well accepted by the patients and does not interfere with flow hemodynamics.

OBJECTIVES

The present study was aimed to evaluate the association between color Doppler findings and the severity of portal hypertension in patients with cirrhosis.

PATIENTS AND METHODS

The study group included 50 patients referred for ultrasound (US) evaluation over a period of six months from March to August, 2007. The patients were divided into three groups (Child' A, B and C) based on Child Pugh classification. The direction of flow in the main portal vein (hepatopetal or nonhepatopetal) and peak venous velocity (PVV) in the main portal vein were measured and correlated with the presence or absence of ascites, splenomegaly, splenic and esophageal varices (assessed by Doppler US). These findings were correlated with clinical features and laboratory findings (using Child Pugh's criteria).

RESULTS

There was significant association between the decrease of peak portal venous velocity (PVV) and the increase in Child Pugh score. Hepatofugal flow was seen only in patients with more advanced disease. There was also significant association between PVV and splenic varices and ascites, while PVV was not affected by the presence or absence of esophageal varices or splenomegaly. Presence of a recanalized umbilical vein (UV) was associated with increased PVV even in advanced disease.

CONCLUSIONS

Color Doppler is an excellent modality for detecting and characterizing the complex hemodynamics of portal hypertension in cirrhosis and they correlate with the clinical stage of disease.

Color Doppler evaluation of left gastric vein hemodynamics in cirrhosis with portal hypertension and its correlation with esophageal varices and variceal bleed

AIM

The purpose of this study was to assess the value of Doppler evaluation of left gastric vein hemodynamics when monitoring portal hypertension patients, by correlating Doppler ultrasonography (USG) parameters with the severity of esophageal varices and occurrence of variceal bleeding.

METHODS

This study was carried out on 100 patients using Doppler USG and endoscopy. Forty-seven of these were patients with cirrhosis with portal hypertension, who had not had a recent variceal bleed (group 1) and 26 were patients with cirrhosis with portal hypertension, with a recent history of bleeding (group 2). The control group comprised of 27 subjects who did not have liver disease or varices on endoscopy (group 3). The hemodynamic parameters, namely the diameter of the left gastric vein and the direction and flow velocity in the vessel, were compared in these groups, with the grade of esophageal varices.

RESULTS

Hepatofugal flow velocity in the left gastric vein was higher in patients with large-sized varices compared to those patients with small-sized varices (P < 0.001). The left gastric vein hepatofugal flow velocity was higher in patients with a recent variceal bleed than in those patients without a history of a recent variceal bleed (P < 0.0149). Large-sized varices were more commonly found in patients with a history of a recent variceal bleed (P < 0.0124).

CONCLUSION

Left gastric vein hemodynamics were found to correlate with the severity of the varices and the occurrence of recent variceal bleed in patients with cirrhosis with portal hypertension. Evaluation of the left gastric vein portal dynamics could be helpful in monitoring the progress of the disease in these patients.

High incidence of hepatitis B infection-associated cirrhosis and hepatocellular carcinoma in the Southeast Asian patients with portal vein thrombosis

Background

Portal vein thrombosis (PVT) is a rare condition associated with serious morbidity and mortality. The objective of this study was to determine the frequency, clinical presentations, and risk factors of PVT from the set of data firstly collected among the Southeast Asian population.

Methods

A retrospective study was undertaken to identify patients diagnosed with thrombosis of the portal system and other abdominal veins. The hospital medical records were retrieved based on the selected ICD-10 codes. Clinical presentations were collected and risk factors determined.

Results

From 2000-2009, 467 hospital charts with designated ICD-10 codes of I81, I82.2, I82.3, I82.8, I82.9, or K55.0 were identified. PVT (I81) was the most common thrombosis (194 cases, 41.54%). The majority of PVT patients were males (65%), older than 40 years (75%), and presented with abdominal distension/ascites (69%), splenomegaly (54.6%), and abdominal pain (50.5%). Overall, the predominant risk factor was hepatocellular carcinoma (HCC) (52.5%), followed by liver cirrhosis without cancer (9.3%), abdominal infection/inflammation (9.3%), cholangiocarcinoma (8.2%), and abdominal intervention (7.7%). In young patients, abdominal interventions including umbilical catheterization (23.1%) and hepatectomy (7.7%) were the most frequent risks whereas in older cases, primary hepatobiliary cancer and cirrhosis (78%) were the major risks. Liver metastases from other organs were infrequently found. Chronic hepatitis B virus (HBV) infection was the main etiology associated with cirrhosis/HCC leading to PVT in this cohort. A third of the older PVT patients (age >40) had HBV and very few carried hepatitis C virus (HCV) whereas none of the young PVT patients (age <20) had HBV or HCV. A variety of abdominal infections/inflammations were also found including liver abscess, splenic abscess, cholangitis, cholecystitis, pancreatitis, omphalitis, and abdominal tuberculosis. Single cases of systemic lymphangiomatosis and Klippel-Trénaunay vascular malformation syndrome were also identified. Other thrombophilic conditions such as myeloproliferative neoplasms, paroxysmal nocturnal hemoglobinuria, protein S deficiency, and anti-phospholipid syndrome were rarely encountered.

Conclusion

HBV is the major risk of PVT in the Southeast Asian population. Several risk factors identified in this population have rarely been described and some are remarkably different from those reported in the West. Host and environmental factors may play a causal role in the initiation and development of PVT in various ethnicities and geographic locations.

Criteria for diagnosing benign portal vein thrombosis in the assessment of patients with cirrhosis and hepatocellular carcinoma for liver transplantation

Malignant portal vein thrombosis is a contraindication for liver transplantation. Patients with cirrhosis and early hepatocellular carcinoma (HCC) may have either malignant or benign (fibrin clot) portal vein thrombosis. The aim of this study was to assess prospectively whether well-defined diagnostic criteria would enable the nature of portal vein thrombosis to be established in patients with HCC under consideration for liver transplantation. Benign portal vein thrombosis was diagnosed by the application of the following criteria: lack of vascularization of the thrombus on contrast-enhanced ultrasound and on computed tomography or magnetic resonance imaging, absence of mass-forming features of the thrombus, absence of disruption of the walls of veins, and, if uncertainty persisted, biopsy of the thrombus for histological examination. Patients who did not fulfill the criteria for benign thrombosis were not placed on the transplantation list. In this study, all patients evaluated at our center during 2001-2007 with a diagnosis of HCC in whom portal vein thrombosis was concurrently or subsequently diagnosed were discussed by a multidisciplinary group to determine their suitability for liver transplantation. The outcomes for 33 patients who met the entry criteria of the study were as follows: in 14 patients who were placed on the transplantation list and underwent liver transplantation, no malignant thrombosis was detected when liver explants were examined histologically; 5 patients who were placed on the transplantation list either remained on the list or died from causes unrelated to HCC; in 9 patients, liver transplantation was contraindicated on account of a strong suspicion, or confirmation, of the presence of malignant portal vein thrombosis; and 5 patients who were initially placed on the transplantation list were subsequently removed from it on account of progression of HCC in the absence of evidence of neoplastic involvement of thrombosis. In conclusion, for a patient with HCC and portal vein thrombosis, appropriate investigations can establish whether the thrombosis is benign; patients with HCC and benign portal vein thrombosis are candidates for liver transplantation.

Systematic review: portal vein thrombosis in cirrhosis

BACKGROUND

As current imaging techniques in cirrhosis allow detection of asymptomatic portal vein thrombosis during routine ultrasonography, more patients with cirrhosis are diagnosed with portal vein thrombosis. Although a consensus on noncirrhotic extra-hepatic portal vein thrombosis has been published, no such consensus exists for portal vein thrombosis with cirrhosis.

AIM

To perform a systematic review of nonmalignant portal vein thrombosis in cirrhosis in terms of prevalence, pathogenesis, diagnosis, clinical course and management.

METHODS

Studies were identified by a search strategy using MEDLINE and EMBASE.

RESULTS

Portal vein thrombosis is encountered in 10-25% of cirrhotics. In terms of pathophysiology, cirrhosis is no longer considered a hypocoagulable state; rather than a bleeding risk in cirrhosis, various clinical studies support a thrombotic potential. Clinical findings of portal vein thrombosis in cirrhosis vary from asymptomatic disease to a life-threatening condition at first presentation. Optimal management of portal vein thrombosis in cirrhosis is currently not addressed in any consensus publication. Treatment strategies most often include the use of anticoagulation, while thrombectomy and transjugular intrahepatic portosystemic shunts are considered second-line options.

CONCLUSIONS

Portal vein thrombosis in cirrhosis has many unresolved issues, which are often the critical problems clinicians encounter in their everyday practice. We propose a possible research agenda to address these unresolved issues.

Protein C and D-dimer are related to portal vein thrombosis in patients with liver cirrhosis

BACKGROUND AND AIM

To profile changes of coagulation, anticoagulation and fibrolytic factors associated with liver function failure and portal vein thrombosis (PVT) formation in chronic liver cirrhosis patients.

METHODS

A total of 116 cirrhotic patients admitted to our hospital from June 2006 to October 2008 were included in our study. All patients were classified into two groups: PVT group (31 patients), composed of patients with PVT and a control group (85 patients), including patients without PVT. Platelet, prothrombin time (PT), activated partial prothrombin time (APTT) and fibrinogen were measured. Also, plasma samples from the patients were analyzed for the levels of antithrombin III (AT-III), protein C (PC), protein S (PS), D-dimer, tissue-type plasminogen activator as well as plasminogen activator inhibitor-1. Statistical analyses were carried out to evaluate the correlation of specific variations with the disease status.

RESULTS

In general, the higher Child-Pugh scores, indicating the aggravation of hepatic impairment of the patients, correlated well with the prolonged PT/APTT and increased D-dimer, as well as decreased platelet, fibrinogen, PC and AT-III levels in the serum. Furthermore, we found that the PC, PS and D-dimer levels in PVT patients were 2.32 +/- 0.72 mg/L, 17.14 +/- 3.62 mg/L and 0.99 +/- 0.36 mg/L, respectively, both representing a significant difference compared with those in the control group without PVT. Logistic regression model shows that the odds ratio value of one unit of increase of PC and D-dimer were 0.48 and 15.57.

CONCLUSIONS

Cirrhotic patients displayed dysfunctions in the coagulation, anti-coagulation and fibrolytic systems. The development of PVT in these patients may be independently associated with the decrease of PC, PS and D-dimer. Furthermore, decreasing PC and increasing D-dimer may be risk factors inducing PVT in cirrhotic patients.

Management of portal vein thrombosis in cirrhotic patients

Portal vein thrombosis (PVT) not associated with hepatocellular carcinoma is considered a frequent complication of liver cirrhosis but, unlike PVT occurring in non-cirrhotic patients, very few data are available on its natural history and management. The reduced portal blood flow velocity is the main determinant of PVT but, as in other venous thromboses, multiple factors local and systemic, inherited or acquired often can concur with. PVT has a variety of clinical presentations ranging from asymptomatic to life-threatening diseases like gastroesophageal bleeding or acute intestinal ischemia. It is usually diagnosed by Doppler ultrasound but computed tomography and magnetic resonance imaging are useful to study the extent of thrombosis and the involvement of the abdominal organs. The risk of bleeding mainly determined by the presence of gastroesophageal varices and clotting alterations causes concern for the treatment of PVT in cirrhotic patients. To date, anticoagulant therapy seems to be indicated only in patients awaiting liver transplantation. This review focuses on the definition of the subgroups of patients with cirrhosis that might benefit from treatment of PVT and examines the pros and cons of the available treatments in terms of efficacy, monitoring and safety, providing also perspectives for future studies.

Thrombotic risk factors in patients with liver cirrhosis: correlation with MELD scoring system and portal vein thrombosis development

BACKGROUND/AIMS

Prognostic scores currently used in cirrhotic patients do not include thrombotic risk factors (TRFs). Predicting factors of portal vein thrombosis (PVT) development are still unknown. We wanted to describe TRFs as a function of liver disease severity using the MELD score and assess the role of local and systemic TRFs as predictors of PVT development in cirrhotic patients.

METHODS

One hundred consecutive patients with liver cirrhosis were included in the study. TRFs, D-dimers, MELD score, portal vein patency and flow velocity were evaluated in all subjects at baseline and every 6 months thereafter. Variables able to predict PVT development within 1 year were identified by means of multiple logistic regression.

RESULTS

The plasma levels of protein C and antithrombin were lower and the concentration of D-dimers was higher in patients with advanced disease. Plasma levels of antithrombin, protein C and protein S resulted significantly lower in PVT group at univariate analysis, but reduced portal vein flow velocity was the only variable independently associated with PVT development.

CONCLUSIONS

Lower concentrations of natural coagulation inhibitors are frequently detected in patients with liver cirrhosis. A reduced portal flow velocity seems to be the most important predictive variable for PVT development in patients with cirrhosis.

Correlation of routinely used coagulation parameters and presence of portal vein thrombosis in patients with liver cirrhosis

AIM

Portal vein thrombosis (PVT) is a serious complication in patients with liver cirrhosis. In patients with advanced stages of liver cirrhosis plasmatic coagulation and platelet count are often reduced. However, patients with normal coagulation status might carry a high risk for developing PVT. A correlation between coagulation status used in clinical routine and the incidence of PVT in patients with liver cirrhosis has been evaluated in the present retrospective analysis.

METHODS

88 patients with liver cirrhosis were identified by screening a database. Of these patients, 23 suffered from PVT. Patients were classified according to the Child-Pugh classification. Patients were subdivided into early stages (Child A) and advanced stages (Child B/C) of liver cirrhosis.

RESULTS

In patients with Child-Pugh A cirrhosis, there was no difference in activated partial thromboplastin time (apTT), international normalized ratio (INR), and platelet count between the PVT (n = 7) and the control group (n = 35). In contrast, the median apTT and INR were significantly lower in patients with Child B/C cirrhosis and PVT (n = 16) in comparison with patients without PVT (37 s vs 43 s [P = 0.017] and 1.25 vs 1.40 [P = 0.022]), respectively. Platelet count did not differ significantly in patients with advanced liver cirrhosis and PVT from those without PVT.

CONCLUSION

Patients with advanced liver cirrhosis and PVT displayed lower apTT and INR compared with those without PVT. Therefore, patients with advanced liver cirrhosis and almost normal coagulation parameters might be at particular risk of developing PVT. The results suggest that regular monitoring using Doppler-ultrasound should be carried out in these patients, especially when liver transplantation is intended.

Portosystemic shunts in a large cohort of patients with liver cirrhosis: detection rate and clinical relevance

BACKGROUND

This study aimed to determine the detection rate and clinical relevance of portosystemic collaterals.

METHODS

We studied 326 cirrhotics. Portosystemic collaterals, portal vein diameter, and splenic area were evaluated by color Doppler sonography; esophageal varices were detected by endoscopy.

RESULTS

Of the cirrhotics, 130 had portosystemic collaterals (39.9% total, left gastric vein 11%, paraumbilical vein 7.4%, splenorenal shunts 13.8%, and combined shunts 7.7%). Cirrhotics without portosystemic collaterals or with a paraumbilical vein had a significantly narrower portal vein diameter than cirrhotics with a left gastric vein (P < 0.001). Cirrhotics with a paraumbilical vein had a significantly smaller splenic area than cirrhotics with a left gastric vein (P < 0.001), splenorenal shunts (P < 0.001), combined shunts (P < 0.001), or without portosystemic collaterals (P < 0.05). A significant association between portosystemic collaterals and Child's classes or presence and type of esophageal varices was found (P < 0.0001 and P = 0.0004, respectively). The highest prevalence of Child's class C and large (F-3) esophageal varices was found in cirrhotics with a left gastric vein (41.7% and 36.1%, respectively), whereas esophageal varices were absent in 47.4% of cirrhotics without portosystemic collaterals and in 58.3% of cirrhotics with a paraumbilical vein.

CONCLUSIONS

The left gastric vein is associated with some sonographic and clinical markers of disease severity, whereas the absence of portosystemic collaterals or the presence of paraumbilical veins seems to identify cirrhotics with markers predictive of a more favorable clinical course.

Portal vein thrombosis in liver cirrhosis

Portal vein thrombosis (PVT) is observed in 10-20% of patients with liver cirrhosis, which is responsible for 20% of all PVT cases. The main pathogenic factor of PVT in cirrhosis is the obstacle to portal flow, but acquired and inherited clotting abnormalities may play a role. The formation of collateral veins allows many patients to remain asymptomatic and prevents the onset of clinical complications also in patients with totally occlusive PVT. Gastrointestinal bleeding, thrombosis of superior mesenteric vein and refractory ascites are typical manifestations of PVT. Instrumental diagnosis can be obtained by colour-doppler ultrasonography. Future studies should verify whether asymptomatic PVT worsens liver failure, or if its life-threatening complications reduce survival in patients with cirrhosis. Moreover, randomized controlled trials should clarify the potential effectiveness of anticoagulant therapy in the treatment of PVT.

Contrast-enhanced ultrasound in the diagnosis of hepatocellular carcinoma

Surveillance of patients at risk of developing hepatocellular carcinoma (HCC) is based on ultrasound (US) examinations performed at either 6 or 12 month intervals. Early detection of HCC in patients with cirrhosis is a challenging issue, since the different entities that are involved in the multi-step process of hepatocarcinogenesis--such as low-grade and high-grade dysplastic nodule--share common US features. Contrast-enhanced US allows reliable detection of arterial neoangiogenesis associated with a malignant transformation. Several reports have shown that the ability of contrast-enhanced US to diagnose HCC currently approaches that of optimized multidetector computed tomography (CT) or dynamic magnetic resonance (MR) imaging protocols. The use of contrast-enhanced US to characterize nodular lesions in cirrhosis has been recently recommended by the clinical practice guidelines issued by the European Federation of Societies for Ultrasound in Medicine and Biology and the American Association for the Study of Liver Diseases. However, contrast-enhanced US has not resulted in any significant improvement in the ability of US to detect small tumor foci, since a comprehensive assessment of the whole liver parenchyma cannot be accomplished during the short duration of the arterial phase. Hence, CT or MR imaging are still mandatory for proper intrahepatic staging of the disease.

Diagnosis of benign and malignant portal vein thrombosis in cirrhotic patients with hepatocellular carcinoma: color Doppler US, contrast-enhanced US, and fine-needle biopsy

BACKGROUND

We assessed the role of contrast-enhanced ultrasound (CEUS) in the differential diagnosis between benign and malignant portal vein thrombosis in patients who had cirrhosis with hepatocellular carcinoma (HCC).

METHODS

Fifty-four consecutive patients who had cirrhosis, biopsy-proved HCC, and thrombosis of the main portal vein and/or left/right portal vein on US were prospectively studied with color Doppler US (CDUS) and CEUS. CEUS was performed at low mechanical index after intravenous administration of a second-generation contrast agent (SonoVue, Bracco, Milan, Italy). Presence or absence of CDUS signals or thrombus enhancement on CEUS were considered diagnostic for malignant or benign portal vein thrombosis. Twenty-eight patients also underwent percutaneous portal vein fine-needle biopsy (FNB) under US guidance. All patients were followed-up bimonthly by CDUS. Shrinkage of the thrombus and/or recanalization of the vessels on CDUS during follow-up were considered definitive evidence of the benign nature of the thrombosis, whereas enlargement of the thrombus, disruption of the vessel wall, and parenchymal infiltration over follow-up were considered consistent with malignancy. CDUS, CEUS, and FNB results were compared with those at follow-up.

RESULTS

Follow-up (4 to 21 months) showed signs of malignant thrombosis in 34 of 54 patients. FNB produced a true-positive result for malignancy in 19 of 25 patients, a false-negative result in six of 25 patients, and a true-negative result in three of three patients. CDUS was positive in seven of 54 patients. CEUS showed enhancement of the thrombus in 30 of 54 patients. No false-positive result was observed at CDUS, CEUS, and FNB. Sensitivities of CDUS, CEUS, and FNB in detecting malignant thrombi were 20%, 88%, and 76% respectively. Three patients showed negative CDUS and CEUS and positive FNB results; follow-up confirmed malignant thrombosis in these patients. One patient showed negative CDUS, CEUS, and FNB findings. However, follow-up of the thrombus showed US signs of malignancy. Another FNB confirmed HCC infiltration of the portal vein.

CONCLUSION

CEUS seems to be the most sensitive and specific test for diagnosing malignant portal vein thrombosis in patients with cirrhosis.