Portal hypertension

From Pathophysiology to Practice: Evolving Pharmacological Therapies, Clinical Complications, and Pharmacogenetic Considerations in Portal Hypertension

Background: Portal hypertension is a major complication of chronic liver diseases, leading to serious issues such as esophageal variceal bleeding. The increase in portal vein pressure is driven by both an organic component and a functional component, including tonic contraction of hepatic stellate cells. These processes result in a pathological rise in intrahepatic vascular resistance, stemming from partial impairment of hepatic microcirculation, which is further exacerbated by abnormalities in extrahepatic vessels, including increased portal blood flow. Objectives: This review aims to provide a comprehensive overview of the evolving pharmacological therapies for portal hypertension, with consideration and discussion of pathophysiological mechanisms, clinical complications, and pharmacogenetic considerations, highlighting potential directions for future research. Methods: A review of recent literature was performed to evaluate current knowledge and potential therapeutic strategies in portal hypertension. Results: For over 35 years, non-selective beta-blockers have been the cornerstone therapy for portal hypertension by reducing portal vein inflow as an extrahepatic target, effectively preventing decompensation and variceal hemorrhages. However, since not all patients exhibit an adequate response to non-selective beta-blockers (NSBBs), and some may not tolerate NSBBs, alternative or adjunctive therapies that enhance the effects of NSBBs on portal pressure are being investigated in preclinical and early clinical studies. Conclusions: A better understanding of pharmacogenetic factors and pathophysiological mechanisms could lead to more individualized and effective treatments for portal hypertension. These insights highlight potential directions for future research.

The Utility of the Platelet-Albumin-Bilirubin Score as a Non-invasive Predictor of Esophageal Varices and Variceal Hemorrhage in Patients With Liver Cirrhosis Compared to Child-Turcotte-Pugh and Model of End-Stage Liver Disease-Sodium Scores

Introduction Research on non-invasive tools for detecting gastro-esophageal varices is underway. We investigated the Platelet-Albumin-Bilirubin (PALBI) score in comparison with the Child-Turcotte-Pugh (CTP) and MELD-Na (MELD-Na) scores in patients with liver cirrhosis. Methods Three hundred and twenty-three patients with liver cirrhosis were studied. The PALBI, CTP and MELD-Na scores were calculated and analyzed for gastroesophageal varices and their characteristics using SPSS version 26 (IBM Corp., Armonk, NY, USA). Results Two hundred and sixty-four patients had esophageal varices and 102 presented with variceal hemorrhage. Mean PALBI, CTP and MELD-Na scores were significantly higher for patients with varices versus without varices (p < 0.05). Unlike the mean MELD-Na score, the mean PALBI and CTP scores were significantly higher in patients with large high-risk varices as compared to patients with small low-risk varices (p < 0.05). The mean CTP scores were significantly higher in patients with variceal hemorrhage than those without hemorrhage (p < 0.05), while the difference between mean PALBI and MELD-Na was insignificant, in this regard. The PALBI score had better sensitivity than the CTP and MELD-Na scores in indicating the presence of varices but was similar to the CTP score in predicting high-risk varices. Conclusion The PALBI score proves to have good utility and efficiency in predicting varices in comparison to CTP and MELD-Na scores. It can determine high-risk stigmata of variceal hemorrhage with similar performance as the CTP Score.

Spleen stiffness: a new tool to predict high-risk varices in cirrhotic patients

INTRODUCTION

Cirrhosis is one of the major causes of morbidity and mortality worldwide. Portal hypertension is the major contributor of cirrhosis-related complications and is defined as a hepatic venous pressure gradient (HVPG) > 5 mmHg. Measurement of HVPG is an invasive, difficult, and costly procedure. Therefore, it is only performed in specialized centers. Liver stiffness measured with transient elastography is one of the most studied noninvasive markers of portal hypertension, and spleen elastography has recently emerged as an important adjuvant tool. The development of a new probe (100 Hz) that more reliably reflect the grade of portal hypertension evaluated by spleen stiffness measurement has improved the accuracy of this technique. The aim of this work was to evaluate the accuracy of spleen stiffness with the new dedicated probe to predict the presence of high-risk varices, as well as to determine the ideal cutoff to predict it.

METHODS

Prospective study of cirrhotic patients admitted to upper endoscopy that were also submitted to liver and spleen elastography with the 100-Hz probe by the same blinded operator in a tertiary center.

RESULTS

We included 209 cirrhotic patients, with mean age of 61.9 years (±9.9), 77.0% male. The most common etiology was alcoholic liver disease (72.7%). The median value of liver elastography was 25.3 [4.5-75] kPa, and the median value of spleen elastography was 42.4 [7.6-100] kPa. At the cutoff of 53.25 kPa, we obtained sensitivity of 100% and specificity of 72.6% to predict high-risk varices, and, according to this cutoff, 133/175 of esophagogastroduodenoscopy could have been spared (76.0%), while according to Baveno guidelines, only 51/175 would have been spared (29.1%).

CONCLUSION

In the era of noninvasive exams, spleen elastography with the 100-Hz probe emerges as an excellent tool for prediction of presence of high-risk varices. At the cutoff of 53.25 kPa, spleen elastography avoids upper endoscopy for screening for high-risk varices, promising to be become part of the hepatologists' daily routine.

Deep Neural Network Regression to Assist Non-Invasive Diagnosis of Portal Hypertension

Portal hypertension is a complex medical condition characterized by elevated blood pressure in the portal venous system. The conventional diagnosis of such disease often involves invasive procedures such as liver biopsy, endoscopy, or imaging techniques with contrast agents, which can be uncomfortable for patients and carry inherent risks. This study presents a deep neural network method in support of the non-invasive diagnosis of portal hypertension in patients with chronic liver diseases. The proposed method utilizes readily available clinical data, thus eliminating the need for invasive procedures. A dataset composed of standard laboratory parameters is used to train and validate the deep neural network regressor. The experimental results exhibit reasonable performance in distinguishing patients with portal hypertension from healthy individuals. Such performances may be improved by using larger datasets of high quality. These findings suggest that deep neural networks can serve as useful auxiliary diagnostic tools, aiding healthcare professionals in making timely and accurate decisions for patients suspected of having portal hypertension.

Computed Tomography-Based Texture Features for the Risk Stratification of Portal Hypertension and Prediction of Survival in Patients With Cirrhosis: A Preliminary Study

OBJECTIVE

Clinical evidence suggests that the risk stratification of portal hypertension (PH) plays a vital role in disease progression and patient outcomes. However, the gold standard for stratifying PH [portal vein pressure (PVP) measurement] is invasive and therefore not suitable for routine clinical practice. This study is aimed to stratify PH and predict patient outcomes using liver or spleen texture features based on computed tomography (CT) images non-invasively.

METHODS

A total of 114 patients with PH were included in this retrospective study and divided into high-risk PH (PVP ≥ 20 mm Hg, n = 57) or low-risk PH (PVP < 20 mm Hg, n = 57), a progression-free survival (PFS) group (n = 14), or a non-PFS group (n = 51) based on patients with rebleeding or death after the transjugular intrahepatic portosystemic shunt (TIPS) procedure. All patients underwent contrast-enhanced CT, and the laboratory data were recorded. Texture features of the liver or spleen were obtained by a manual drawing of the region of interest (ROI) and were performed in the portal venous phase. Logistic regression analysis was applied to select the significant features related to high-risk PH, and PFS-related features were determined by the Cox proportional hazards model and Kaplan-Meier analysis. Receiver operating characteristic (ROC) curves were used to test the diagnostic capacity of each feature.

RESULTS

Five texture features (one first-order feature from the liver and four wavelet features from the spleen) and the international normalized ratio (INR) were identified as statistically significant for stratifying PH (p < 0.05). The best performance was achieved by the spleen-derived feature of wavelet.LLH_ngtdm_Busyness, with an AUC of 0.72. The only log.sigma.3.0.mm.3D_firstorder_RobustMeanAbsoluteDeviation feature from the liver was associated with PFS with a C-index of 0.72 (95% CI 0.566-0.885), which could stratify patients with PH into high- or low-risk groups. The 1-, 2-, and 3-year survival probabilities were 66.7, 50, and 33.3% for the high-risk group and 93.2, 91.5, and 84.4% for the low-risk group, respectively (p < 0.05).

CONCLUSION

CT-based texture features from the liver or spleen may have the potential to stratify PH and predict patient survival.

Sonographic Evaluation of Pelvic Venous Disorders

ABSTRACT

Pelvic venous disorders are a group of interrelated conditions characterized by venous incompetence. These conditions often manifest with nonspecific symptoms that overlap with many gynecological, gastrointestinal, and urologic diseases. Clinical diagnosis can be difficult, and imaging can play a vital role in differentiating etiology. Sonographic evaluation is often the first step in evaluating these symptoms. Special attention to possible underlying pelvic venous disorders can reveal characteristic findings, support diagnosis, and guide treatment. Here we review pelvic congestion syndrome, nutcracker syndrome, May-Thurner syndrome, and other venous disorders, with a specific focus on sonographic findings and considerations.

Portal vein thrombosis: an overview of current treatment options

Portal vein thrombosis (PVT) is a splanchnic vascular disorder characterised by a recent or chronic thrombotic occlusion of the portal venous system. Its aetiology is miscellaneous, and its management is demanding since PVT can play a critical role as far as morbidity and mortality are concerned. Indeed, PVT can develop as a complication of portal hypertension (PH), in association or not with advanced chronic liver disease, and aggravate its clinical consequences such as variceal bleeding and ascites. Furthermore, a diagnosis of PVT in a non-cirrhotic context can potentially reveal a previously unknown hypercoagulable condition, requiring further diagnostic steps and specific treatment in addition to anticoagulation. In addition to established therapeutic approaches, new strategies, including newer pharmacological treatments and interdisciplinary invasive procedures, gain more attention and have been increasingly introduced into clinical practice. This review aims at discussing the current knowledge in terms of treatment options for PVT.

A novel spleen-dedicated stiffness measurement by FibroScan® improves the screening of high-risk oesophageal varices

BACKGROUND & AIMS

Several non-invasive tests (NITs) have been developed to diagnose oesophageal varices (EV), including the recent Baveno VI criteria to rule out high-risk varices (HRV). Spleen stiffness measurement (SSM) with the standard FibroScan® (SSM@50Hz) has been evaluated. However, the EV grading could be underestimated because of a ceiling threshold (75 kPa) of the SSM@50Hz. The aims were to evaluate SSM by a novel spleen-dedicated FibroScan® (SSM@100Hz) for EV diagnosis compared with SSM@50Hz, other validated NITs and Baveno VI criteria.

METHODS

This prospective multicentre study consecutively enrolled patients with chronic liver disease; blood data, endoscopy, liver stiffness measurement (LSM), SSM@50Hz and SSM@100Hz were collected.

RESULTS

Two hundred and sixty patients met inclusion criteria. SSM@100Hz success rate was significantly higher than that of SSM@50Hz (92.5% vs 76.0%, P < .001). SSM@100Hz accuracy for the presence of EV (AUC = 0.728) and HRV (AUC = 0.756) was higher than in other NITs. SSM@100Hz AUC for large EV (0.782) was higher than SSM@50Hz (0.720, P = .027). AUC for HRV with SSM@100Hz (0.780) was higher than with LSM (0.615, P < .001). The spared endoscopy rate of Baveno VI criteria (8.1%) was significantly increased by the combination to SSM@50Hz (26.5%) or SSM@100Hz (38.9%, P < .001 vs others). The missed HRV rate was, respectively, 0% and 4.7% for combinations.

CONCLUSIONS

SSM@100Hz is a new performant non-invasive marker for EV and HRV providing a higher accuracy than SSM@50Hz and other NITs. The combination of Baveno VI criteria and SSM@100Hz significantly increased the spared endoscopy rate compared to Baveno VI criteria alone or combined with SSM@50Hz. Clinical trial number: NCT02180113.

Portal pressure and liver stiffness measurements in the prediction of fibrosis regression after sustained virological response in recurrent hepatitis C

Sustained virological response (SVR) improves survival in post-liver transplant (LT) recurrent hepatitis C. However, the impact of SVR on fibrosis regression is not well defined. In addition, the performance of noninvasive methods to evaluate the presence of fibrosis and portal hypertension (PH) post-SVR has been scarcely evaluated. We aimed to investigate the degree of fibrosis regression (decrease ≥1 METAVIR stage) after-SVR and its associated factors in recurrent hepatitis C, as well as the diagnostic capacity of noninvasive methods in the assessment of liver fibrosis and PH after viral clearance. We evaluated 112 hepatitis C virus-infected LT recipients who achieved SVR between 2001 and 2015. A liver biopsy was performed before treatment and 12 months post-SVR. Hepatic venous pressure gradient (HVPG), liver stiffness measurement (LSM), and Enhanced Liver Fibrosis (ELF) score were also determined at the same time points. Sixty-seven percent of the cohort presented fibrosis regression: 43% in recipients with cirrhosis and 72%-85% in the remaining stages (P = 0.002). HVPG, LSM, and ELF significantly decreased post-SVR. Liver function significantly improved, and survival was significantly better in patients achieving fibrosis regression. Baseline HVPG and LSM as well as decompensations before therapy were independent predictors of fibrosis regression. One year post-SVR, LSM had a high diagnostic accuracy to discard the presence of advanced fibrosis (AF) and clinically significant PH (AUROC, 0.902 and 0.888).

CONCLUSION

In conclusion, SVR post-LT induces fibrosis regression in most patients, leading to significant clinical benefits. Pretreatment HVPG and LSM are significant determinants of the likelihood of fibrosis regression. Finally, LSM accurately predicts the presence of AF and PH 1 year after SVR and thus can be used to determine monitoring strategies. (Hepatology 2018;67:1683-1694).

Measurement of Spleen Stiffness With Acoustic Radiation Force Impulse Imaging Predicts Mortality and Hepatic Decompensation in Patients With Liver Cirrhosis

BACKGROUND & AIMS

Hepatic venous pressure gradient can predict mortality and hepatic decompensation in patients with cirrhosis. Measurement of hepatic venous pressure gradient requires an invasive procedure; therefore, prognostic markers are needed that do not require invasive procedures. We investigated whether measurements of spleen stiffness, made by acoustic radiation force impulse (ARFI) imaging, associated with mortality and decompensation in patients with cirrhosis, compared with liver stiffness and other markers.

METHODS

We measured spleen stiffness in 393 patients diagnosed with cirrhosis (based on histologic or physical, laboratory, and radiologic findings) at a hospital in Japan from September 2010 through August 2013 (280 patients with compensated and 113 patients with decompensated cirrhosis). Patients underwent biochemical, ARFI, ultrasonography, and endoscopy evaluations every 3 or 6 months to screen for liver-related complications until their death, liver transplantation, or the end of the study period (October 2015). The primary outcome was the accuracy of spleen stiffness in predicting mortality and decompensation, measured by Cox proportional hazards model analysis. We compared spleen stiffness with other noninvasive parameters using the Harrell's C-index analysis.

RESULTS

During a median follow-up period of 44.6 months, 67 patients died and 35 patients developed hepatic decompensation. In the multivariate analysis, spleen stiffness was an independent parameter associated with mortality, after adjustment for levels of alanine aminotransferase and serum sodium, and the model for end-stage liver disease score (P < .001). Spleen stiffness was associated independently with decompensation after adjustment for Child-Pugh score and model for end-stage liver disease score (P < .001). Spleen stiffness predicted mortality and decompensation with greater accuracy than other parameters (C-indexes for predicting mortality and decompensation were 0.824 and 0.843, respectively). A spleen stiffness cut-off value of 3.43 m/s identified the death of patients with a 95.3% negative predictive value and 75.8% accuracy. A spleen stiffness cut-off value of 3.25 m/s identified patients with decompensation with a 98.8% negative predictive value and 68.9% accuracy.

CONCLUSIONS

Spleen stiffness, measured by ARFI imaging, can predict death of patients with cirrhosis with almost 76% accuracy and hepatic decompensation with almost 70% accuracy. It might be a useful noninvasive test to predict patient outcome. UMIN Clinical Trials Registry no. UMIN000004363.

Point Shear Wave Elastography to Evaluate and Monitor Changing Portal Venous Pressure in Patients with Decompensated Cirrhosis

This study evaluated whether the stiffness of the liver and spleen, measured using the point shear wave elastography (pSWE) technique, correlates with portal venous pressure (PVP) and whether the result extends to estimate the diminishing change in PVP (ΔPVP) in patients with decompensated cirrhosis. We evaluated the data of 67 prospectively enrolled patients who underwent both transjugular intrahepatic portosystemic shunt (TIPS) and pSWE. The stiffness of liver and spleen were evaluated by measuring shear wave velocity (SWV) to determine the statistical correlation with PVP. We also analyzed whether change in SWV (ΔSWV) correlates with ΔPVP. The correlations were assessed with Spearman's rank correlation coefficients. Furthermore, receiver operating characteristic (ROC) curves were constructed to evaluate diagnostic capacity of ΔSWV. Spleen stiffness (SS) was positively correlated with PVP before and after TIPS (p < 0.002), although no correlation between liver stiffness and PVP was detected. A strong relationship between ΔSWV in SS and ΔPVP change in portal hypertension (r = 0.871) was also found in the overall population. The area under the ROC curve for the diagnosis of TIPS technical success was 0.869 and at a ΔSWV cut-off value of 0.36 m/s sensitivity was 77%. Measurement of SS can be used for non-invasive assessment and monitoring of PVP in patients with decompensated cirrhosis.

Spleen and Liver

In liver cirrhosis, the spleen is a source of nitric oxide which affects a hyperdynamic state typical of portal hypertension. It is generally accepted that pancytopenia results predominantly from the increased phagocytosis and destruction of hemocytes in splenic macrophages. In addition, liver fibrosis is amplified by migrated Th2 lymphocytes and transforming growth factor beta from the spleen. There is a possibility that increase of the spleen stiffness is the primary factor of idiopathic portal hypertension. Spleen stiffness is caused by bleeding, fibrosis, and calcareous deposits after increase in red pulp pressure due to venous congestion. In nonalcoholic steatohepatitis, macrophage activity in the spleen is upregulated. In addition, high levels of inflammatory cytokines are produced and T cell shows increased proliferation in the spleen. In autoimmune hepatitis model, CD4⁺ T cells are differentiated into follicular helper T cells (T_FH) in the spleen. T_FH cells promoted hypergammaglobulinemia and antinuclear antibodies production. T_FH cells migrate from the spleen to the liver, triggering induction of autoimmune hepatitis in this model. IgM-positive B cells localize in the CD21-positive lymph follicle in the spleen of primary biliary cholangitis. These findings prove that the spleen influences on the pathogenesis and severity of several kinds of liver disease.

Spleen stiffness correlates with the presence of ascites but not esophageal varices in chronic hepatitis C patients

Although spleen stiffness has recently been identified as potential surrogate marker for portal hypertension, the relationship between spleen stiffness and portal hypertension has not been fully elucidated. We attempted to determine the relationship between the liver or spleen stiffness and the presence of ascites or esophageal varices by acoustic radiation force impulse (ARFI) imaging. A total of 33 chronic hepatitis C (CHC) patients (median age 68; range 51-84) were enrolled. We evaluated the relationship between the liver or spleen stiffness and indicators of portal hypertension as well as clinical and biochemical parameters. Fourteen healthy volunteers were used for validating the accuracy of AFRI imaging. The liver and spleen stiffness increased significantly with progression of liver disease. A significant positive correlation was observed between the liver and spleen stiffness. However, spleen stiffness, but not liver stiffness, was significantly associated with the presence of ascites (P < 0.05), while there was no significant association between the spleen stiffness and spleen index/presence of esophageal varices in CHC patients. The area under the receiver operating characteristic curve based on the spleen stiffness was 0.80. In conclusion, spleen stiffness significantly correlates with the presence of ascites but not esophageal varices in CHC patients.

Coinfection by human immunodeficiency virus and hepatitis C virus: noninvasive assessment and staging of fibrosis

PURPOSE OF REVIEW

This review presents recent findings on noninvasive alternatives for the diagnosis of fibrosis and cirrhosis in patients who are coinfected with HIV and hepatitis C virus (HCV).

RECENT FINDINGS

APRI, FIB-4, and Forns were accurate indices for the diagnosis of cirrhosis [area under the receiver operating characteristic curve (AUROC) >0.80] but not for the diagnosis of significant and advanced fibrosis (AUROC < 0.80). Diagnostic accuracy was affected by CD4 T-cell count and alanine aminotransferase levels. An artificial neural network to predict significant fibrosis was highly accurate (AUROC of 0.853), outperforming simple noninvasive indices. Derivations of the FibroMeter panel (FibroMeter HICV and FibroMeter HICV) achieved high diagnostic accuracy for significant fibrosis (AUROC of 0.823 and 0.833, respectively). Transient elastography had higher predictive accuracy than previously validated panels for diagnosis of advanced fibrosis (F ≥ 3) and cirrhosis (0.93 and 0.99, respectively). However, misclassification as F ≥ 3 was more common among patients with steatosis than among those without steatosis (25 versus 5%, P = 0.01). Moreover, transient elastography can predict clinically significant and severe portal hypertension in HIV/HCV-coinfected patients.

SUMMARY

Both biomarkers and transient elastography can accurately diagnose fibrosis and cirrhosis and are better at excluding than at predicting liver disease in HIV/HCV-coinfected patients.

Predicting portal hypertension as assessed by acoustic radiation force impulse: correlations with the Doppler ultrasound

OBJECTIVE

The purpose of this study was to assess the value of acoustic radiation force impulse (ARFI) for evaluating portal hypertension by correlating the elasticity of liver cirrhosis, as measured by ARFI, with haemodynamic indices measured by Doppler ultrasound.

METHODS

We evaluated the data of a total of 154 prospectively enrolled patients who underwent both duplex Doppler ultrasound and ARFI imaging. The duplex Doppler ultrasound indices, including the mean portal vein velocity, splenic index (SI) and splenoportal index (SPI) were evaluated to determine the statistical correlation with shear wave velocity (SWV) of ARFI. We also analysed the differences in the correlations between the SI, SPI and SWV of the group who had varices. The correlations were assessed with Spearman's rank correlation coefficients.

RESULTS

There was an increase of SWV in parallel with the increase of the SI (ρ=0.409, p<0.01) and SPI (ρ=0.451, p<0.01). In the patient group who did not have varices (n=74), the Doppler indices were found to be more correlated with the SWV (SI: ρ=0.447, SPI: ρ=0.552, p<0.01). However, the group with varices showed no correlation between the SWV and the Doppler parameters.

CONCLUSION

SWV of ARFI was well correlated statistically with Doppler parameters, but is of limited value in predicting portal hypertension directly owing to great variability of Doppler parameters. By evaluating the correlation between ARFI and Doppler ultrasound, we suggest that the SWV might be a non-invasive supplementary tool for predicting portal hypertension.

Measurement of spleen stiffness to evaluate portal hypertension and the presence of esophageal varices in patients with HCV-related cirrhosis

BACKGROUND & AIMS

The hepatic vein pressure gradient (HVPG) is the standard used to determine the degree of portal hypertension (PH) and an important prognostic factor for patients with cirrhosis; HVPG values correlate with the presence of esophageal varices (EV). However, HVPG can only be accurately determined at specialized centers; noninvasive methods are needed to predict HVPG values and the presence of EV. We compared the diagnostic performance of spleen stiffness (SS) measurement by transient elastography with that of liver stiffness (LS) and of other recently proposed noninvasive tests.

METHODS

We measured SS and LS in 100 consecutive patients with hepatitis C virus-induced cirrhosis. Patients were also assessed by FibroScan, HVPG, esophagogastroduodenoscopy, and liver biopsy. We also analyzed LS-spleen diameter to platelet ratio score and platelet count to spleen diameter.

RESULTS

SS and LS were more accurate than other noninvasive parameters in identifying patients with EV and different degrees of PH. A linear model that included SS and LS accurately predicted HVPG values (R(2) = 0.85). The results were internally validated using bootstrap analysis.

CONCLUSIONS

Measurement of SS can be used for noninvasive assessment and monitoring of PH and to detect EV in patients with hepatitis C virus-induced cirrhosis.

ARFI, FibroScan, ELF, and their combinations in the assessment of liver fibrosis: a prospective study

BACKGROUND & AIMS

Our aim was to evaluate a serologic marker (ELF) and two ultrasound-based methods (FibroScan and ARFI), as well as their combinations, in the assessment of liver fibrosis.

METHODS

One-hundred and forty-six patients (87 liver transplant recipients, 59 non-transplant patients) who underwent liver biopsy were prospectively included. We evaluated the diagnostic accuracy of FibroScan, ARFI, ELF and the combination of ELF with either ARFI or FibroScan. After analyzing in separate transplant and non-transplant patients, the whole cohort was divided into a training set and a validation set.

RESULTS

ARFI imaging was successfully performed across the whole cohort, while FibroScan failed in 16 (11%) patients. The three methods showed similar AUROCs and best cut-off values in transplant and non-transplant patients. In the training set, differences between the AUROCs of ARFI, FibroScan and ELF to diagnose F⩾2 (0.879, 0.861, and 0.764, respectively) and cirrhosis (0.936, 0.918, and 0.841) were not statistically significant, although both ultrasound-based methods showed higher accuracy than ELF. The combination of ELF with ARFI or FibroScan increased the negative and positive predictive values of single tests for the diagnosis of F ≥ 2 and cirrhosis. Similar results were obtained when the methods were tested in the validation set.

CONCLUSIONS

ARFI is as effective as either FibroScan or ELF in the non-invasive assessment of liver fibrosis, and its inclusion in an ultrasound device could facilitate its incorporation into routine clinical practice. The combination of ARFI or FibroScan with ELF may help better identify patients with or without significant fibrosis or cirrhosis.

Hemodynamics and pharmacokinetics of tezosentan, a dual endothelin receptor antagonist, in patients with cirrhosis

PURPOSE

To assess the effect of tezosentan, a parenteral dual ET receptor antagonist, on splanchnic and systemic hemodynamics in patients with cirrhosis. In addition, the safety, pharmacokinetics, and pharmacodynamics of tezosentan were evaluated.

METHODS

The population consisted of patients with cirrhosis with clinically significant portal hypertension. This was a randomized, double-blind, multicenter study. The patients were randomized 3:1 to tezosentan (3 mg/h for 2-3 h) or placebo. HVPG, hepatic blood flow (HBF, ICG method), and systemic arterial pressures were measured before and after tezosentan administration. Plasma concentrations of tezosentan and ET-1 were determined peripherally and in the hepatic vein.

RESULTS

Eighteen patients received tezosentan and six placebo. Baseline clinical, biochemical, and hemodynamic characteristics were balanced between the two groups. There was no significant treatment effect on HVPG. The extraction ratio (0.31), the plasma clearance of ICG (280 ml/min), and the HBF (1,430 ml/min) did not show any relevant changes during the infusion of tezosentan, and there were no differences between placebo- and tezosentan-treated patients. A linear relationship was observed between the maximum-fold increase in ET-1 concentration and the steady-state tezosentan plasma concentration (r = 0.82). There was a strong correlation (r = 0.88) between plasma clearance of ICG and that of tezosentan (10.2 l/h). Arterial pressure and heart rate did not significantly change in either group.

CONCLUSION

In patients with cirrhosis, a 2- to 3-h tezosentan infusion was safe and well tolerated but did not change the HVPG. Tezosentan infusion had no influence on the extraction ratio and plasma clearance of ICG and did not change HBF.

Hemodynamics and pharmacokinetics of tezosentan, a dual endothelin receptor antagonist, in patients with cirrhosis

PURPOSE

To assess the effect of tezosentan, a parenteral dual ET receptor antagonist, on splanchnic and systemic hemodynamics in patients with cirrhosis. In addition, the safety, pharmacokinetics, and pharmacodynamics of tezosentan were evaluated.

METHODS

The population consisted of patients with cirrhosis with clinically significant portal hypertension. This was a randomized, double-blind, multicenter study. The patients were randomized 3:1 to tezosentan (3 mg/h for 2-3 h) or placebo. HVPG, hepatic blood flow (HBF, ICG method), and systemic arterial pressures were measured before and after tezosentan administration. Plasma concentrations of tezosentan and ET-1 were determined peripherally and in the hepatic vein.

RESULTS

Eighteen patients received tezosentan and six placebo. Baseline clinical, biochemical, and hemodynamic characteristics were balanced between the two groups. There was no significant treatment effect on HVPG. The extraction ratio (0.31), the plasma clearance of ICG (280 ml/min), and the HBF (1,430 ml/min) did not show any relevant changes during the infusion of tezosentan, and there were no differences between placebo- and tezosentan-treated patients. A linear relationship was observed between the maximum-fold increase in ET-1 concentration and the steady-state tezosentan plasma concentration (r = 0.82). There was a strong correlation (r = 0.88) between plasma clearance of ICG and that of tezosentan (10.2 l/h). Arterial pressure and heart rate did not significantly change in either group.

CONCLUSION

In patients with cirrhosis, a 2- to 3-h tezosentan infusion was safe and well tolerated but did not change the HVPG. Tezosentan infusion had no influence on the extraction ratio and plasma clearance of ICG and did not change HBF.

Use of transient elastography (FibroScan®) for the noninvasive assessment of portal hypertension in HIV/HCV-coinfected patients

The hepatic venous pressure gradient (HVPG) is the gold standard for assessing portal pressure and correlates with the occurrence of portal hypertension (PH)-related complications. Transient elastography (TE) is a new, highly accurate noninvasive technique, which enables us to evaluate hepatic fibrosis to detect advanced fibrosis and cirrhosis. We performed a hepatic haemodynamic study and TE in 38 HIV/HCV-coinfected patients. The association between HVPG and liver stiffness was assessed by linear regression. The diagnostic value of TE was assessed by receiver operating characteristic (ROC) curves. We considered clinically significant PH as an HVPG ≥ 10 mmHg and severe PH as an HVPG ≥ 12 mmHg. A total of 38 HIV/HCV-coinfected patients were included. Twenty-eight patients (73.7%) had clinically significant PH (HVPG ≥ 10 mmHg), and 23 (60.5%) of these had severe PH (HVPG ≥ 12 mmHg). We found a statistically significant association between liver stiffness (kPa) and HVPG (r(2) = 0.46, P < 0.001, straight line equation HVPG=7.4 + 0.204*TE). The areas under the ROC curves were 0.80 [95% confidence interval (CI), 0.64-0.97] and 0.80 (95% CI, 0.66-0.94) for the prediction of HVPG ≥ 10 and ≥ 12 mmHg, respectively. Our data suggest that TE can predict the presence of clinically significant and severe PH in HIV/HCV-coinfected patients.

Hemodynamic consequences of spontaneous splenorenal shunts in deceased donor liver transplantation

The presence of large spontaneous splenorenal shunts (SSRSs) is a risk factor for poor portal vein flow and liver dysfunction. The disconnection of splenorenal shunts by left renal vein (LRV) ligation has been suggested as a potential solution for improving portal flow. We reviewed the hemodynamic consequences of splenorenal shunts in deceased donor liver transplantation and investigated the role of LRV ligation. In 10 patients who underwent liver transplantation at our institution between January 2006 and April 2010, an SSRS was diagnosed preoperatively. Intraoperative portal and hepatic artery flows were measured with a transit time flowmeter. The shunt was disconnected in 6 patients for whom the portal flow after reperfusion was less than or equal to 1200 mL/minute. LRV ligation resulted in significant increases in the portal flow. There were no differences in renal function for the patients who underwent renal vein ligation and the patients who did not undergo ligation. In conclusion, LRV ligation disconnects splenorenal shunts and modulates the portal inflow without any detrimental effects on renal function.

[Relationship between portal pressure gradient and ascites in cirrhotic patients]

CONTEXT

Portal hypertension plays an important role in the pathogenesis of ascites.

OBJECTIVES

To evaluate the hepatic venous pressure gradient and the presence of ascites in cirrhotic patients.

METHODS

Eighty-three patients with cirrhosis were evaluated. All of the patients were submitted to ultrasonography to identify ascites and to a hepatic hemodynamic investigation to determine the hepatic venous pressure gradient.

RESULTS

In the population evaluated, ascites was observed in 70 patients (84.3%), and the mean hepatic venous pressure gradient was 15.26 +/- 6.46 mm Hg. There was no statistically significant difference (P = 0.061) between the means of hepatic venous pressure gradient in patients with (14.70 +/- 6.43 mm Hg) and without ascites (18.64 +/- 5.78 mm Hg). When using a cut-off point of 8 mm Hg in order to assess the risk of developing ascites, patients with hepatic venous pressure gradient above 8 mm Hg were found to have a relative risk of 0.876 (CI = 0.74-1.03), (P = 0.446) of progressing to ascites.

CONCLUSIONS

The pressure level of 8 mm Hg, as determined by the hepatic venous pressure gradient, does not define the presence or absence of ascites in the cirrhotic patient, and in view of the similarity between mean pressures in patients with or without peritoneal effusion, it is impossible to define a cut-off point for the emergence of such complication.

[Usefulness of liver stiffness measurement for predicting the presence of esophageal varices in patients with liver cirrhosis]

BACKGROUND/AIMS

Bleeding from esophageal varices (EV) is a major cause of death in patients with liver cirrhosis. Endoscopic screening is recommended for diagnosing EV, but various noninvasive parameters can also be used to predict EV. The liver stiffness measurement (LSM), a noninvasive technique for estimating liver fibrosis, was recently reported to be strongly correlated with the hepatic venous pressure gradient. This study evaluated the usefulness of LSM for predicting the presence and size of EV in patients with cirrhosis.

METHODS

The relationships of LSM with the presence and size of EV were analyzed in 112 patients with liver cirrhosis. Liver cirrhosis was diagnosed histologically or clinically. The presence and size of EV were assessed by endoscopy, and LSM was determined by the Fibroscan technique.

RESULTS

LSM was strongly correlated with the presence of EV (P<0.0001): the LSM value was 42.7+/-21.9 kPa (mean+/-standard deviation) in patients with EV (n=82) and 19.1+/-12.6 kPa in patients without EV (n=30). The area under the receiver operating characteristic curve was 0.818 (95% CI, 0.732-0.904) for predicting the presence of EV, and an LSM value of 19.7 kPa was predictive of the presence of EV with a sensitivity of 87%, a specificity of 70%, a PPV of 89%, and a NPV of 66%. However, there was a weak correlation between LSM and the size of EV.

CONCLUSIONS

LSM is useful for predicting the presence of EV in patients with cirrhosis but not their size.

Evaluation of solitary and scattered esophageal varices according to infrared endoscopy and endoscopic ultrasonography

BACKGROUND AND AIM

The aim of this study was to clarify the etiology and clinical significance of solitary and scattered esophageal varices by evaluating their hemodynamics and other characteristics using infrared endoscopy and endoscopic ultrasonography.

METHODS

The study group comprised 44 lesions of these two related types detected in 28 patients by visible-light endoscopy. Infrared endoscopy was used to characterize blue-black coloration before and after rapid intravenous injection of indocyanine green (2 mg/kg). During endoscopic ultrasonography, depth within the esophagus and echo patterns of these varices were characterized.

RESULTS

Diameters of these varices were significantly smaller in lesions more strongly staining by infrared endoscopy. Lesion diameter was significantly smaller in varices showing homogeneous low echogenicity than in those showing mixed echogenicity. Lesions showing homogeneous high echogenicity stained most weakly followed in turn by lesions with mixed echogenicity and finally those showing homogeneous low echogenicity.

CONCLUSION

Indocyanine green injection was useful for infrared observation of the hemodynamics of solitary and scattered esophageal varices, as was endoscopic ultrasonography in defining the location and morphology of these lesions. Varices with larger diameters stained more persistently when hemodynamics were evaluated by infrared endoscopy, and often showed a mixture of low and high echogenicity by endoscopic ultrasonography. These observations suggest that blood flow in the varices is slowed, and that the risk of hemorrhage increases with increased diameter especially with uniform enhancement and uniform echogenicity.

Performance of Doppler ultrasound in the prediction of severe portal hypertension in hepatitis C virus-related chronic liver disease

PURPOSE

To evaluate the correlation between hepatic vein pressure gradient measurement and Doppler ultrasonography (DUS) in patients with chronic liver disease (CLD).

PATIENTS AND METHODS

Sixty-six patients with fibrotic to cirrhotic hepatitis C virus-related CLD, were consecutively included upon referral to our haemodynamic laboratory. Superior mesenteric artery pulsatility index (SMA-PI), right interlobar renal and intraparenchymal splenic artery resistance indices, were determined, followed by hepatic venous pressure gradient (HVPG) measurement.

RESULTS

A correlation was found between HVPG and intraparenchymal splenic artery resistance index (SA-RI) (r=0.50, P<0.0001), SMA-PI (r=-0,48, P<0.0001), right interlobar renal artery resistance index (RRA-RI) (r=0.51, P<0.0001) in the whole patient population. However, dividing patients according to the presence/absence of severe portal hypertension (i.e. HVPG > or =12 mmHg), a correlation between HVPG and intraparenchymal SA-RI (r=0.70, P<0.0001), SMA-PI (r=-0.49, P=0.02), RRA-RI (r=0.66, P=0.0002) was observed only for HVPG values <12 mmHg. HVPG but not DUS correlated with the presence of esophageal varices (P<0.0001).

CONCLUSIONS

Superior mesenteric artery pulsatility index, intraparenchymal splenic and right interlobar renal artery resistance indices do not adequately predict severe portal hypertension.

Efficacy of antiviral therapy on hepatitis C recurrence after liver transplantation: a randomized controlled study

BACKGROUND & AIMS

Recurrence of hepatitis C virus (HCV) infection is a relevant problem of liver transplantation programs. We evaluated the effect of antiviral therapy on disease progression in 81 HCV-infected liver transplantation recipients.

METHODS

Patients with mild hepatitis C recurrence (fibrosis stage F0 to F2, n = 54) were randomized to no treatment (group A, n = 27) or peginterferon alfa-2b/ribavirin for 48 weeks (group B, n = 27). Patients with severe recurrence (F3 to F4, cholestatic hepatitis) were treated (group C, n = 27). All patients (n = 81) underwent a liver biopsy at baseline and after follow-up; paired hepatic venous pressure gradient (HVPG) measurements were available in 51 patients.

RESULTS

Thirteen (48%) patients of group B and 5 (18.5%) of group C achieved sustained virological response. Liver fibrosis progressed > or =1 stage in 40 (49%) of 81 patients: 19 (70%) of group A versus 7 (26%) of group B (P = .001) and in 14 (54%) of group C. HVPG increased (6.5 to 13 mm Hg, P < .01) in patients in whom fibrosis worsened, whereas it decreased (5 to 3.5 mm Hg, P = .017) or remained unchanged in those with fibrosis improvement or stabilization, respectively. The only variable independently associated with fibrosis improvement/stabilization was treatment (odds ratio [OR] =3.7, 95% confidence interval [CI] 1.3 to 10, P = .009). Among treated patients, alanine aminotransferase (ALT) normalization and viral clearance were independently associated with histological or hemodynamic improvement/stabilization (OR 5.3, 95% CI 1.5 to 18, P < .01; OR 7.4, 95% CI 1.4 to 38, P = .01; respectively).

CONCLUSIONS

Our data demonstrate that in liver transplantation recipients, antiviral therapy slows disease progression (particularly in sustained virological responders), as shown by its effects on liver histology and on HVPG.

Liver stiffness measurement predicts severe portal hypertension in patients with HCV-related cirrhosis

Measurement of hepatic venous pressure gradient (HVPG) is a standard method for the assessment of portal pressure and correlates with the occurrence of its complications. Liver stiffness measurement (LSM) has been proposed as a noninvasive technique for the prediction of the complications of cirrhosis. In this study, we evaluated the ability of LSM to predict severe portal hypertension compared with that of HVPG in 61 consecutive patients with HCV-related chronic liver disease. A strong relationship between LSM and HVPG measurements was found in the overall population (r=0.81, P<0.0001). However, although the correlation was excellent for HVPG values less than 10 or 12 mm Hg (r=0.81, P=0.0003 and r=0.91, P<0.0001, respectively), linear regression analysis was not optimal for HVPG values>or=10 mm Hg (r2=0.35, P<0.0001) or>or=12 mm Hg (r2=0.17, P=0.02). The AUROC for the prediction of HVPG>or=10 and >or=12 mm Hg were 0.99 and 0.92, respectively and at LSM cutoff values of 13.6 kPa and 17.6 kPa, sensitivity was 97% and 94%, respectively. In patients with cirrhosis, LSM positively correlated with the presence of esophageal varices (P=0.002), although no correlation between LSM and esophageal varices size was detected. The area under the ROC for the prediction of EV was 0.76 and at a LSM cutoff value of 17.6 kPa sensitivity was 90%.

CONCLUSION

LSM represents a non-invasive tool for the identification of chronic liver disease patients with clinically significant or severe portal hypertension and could be employed for screening patients to be subjected to standard investigations including upper GI endoscopy and hemodynamic studies.

Transient elastography for diagnosis of advanced fibrosis and portal hypertension in patients with hepatitis C recurrence after liver transplantation

Recurrence of hepatitis C after liver transplantation (LT) is the main cause of graft loss and retransplantation. Frequent liver biopsies are essential to follow-up hepatitis C virus (HCV)-induced liver damage. However, liver biopsy is an invasive and expensive procedure. We evaluated prospectively the diagnostic accuracy of noninvasive measurement of liver stiffness (by transient elastography) to assess the severity of hepatitis C recurrence after LT. For this purpose, we included 124 HCV-infected liver transplant recipients who underwent 169 liver biopsies and 129 hepatic hemodynamic studies with determination of hepatic venous pressure gradient (HVPG). Simultaneously, patients underwent measurement of liver stiffness. Liver fibrosis was mild (F0-F1) in 96 cases (57%) and significant (F2-F4) in 73 (43%). HVPG was normal (<6 mm Hg) in 69 cases (54%) and elevated (>or=6 mm Hg) in 60 (46%). Using a liver stiffness cutoff value of 8.5 kilopascals, the sensitivity, specificity, negative predictive value, and positive predictive value for diagnosis of fibrosis >or=F2 were 90%, 81%, 79%, and 92%, respectively. The area under the curve (AUC) for diagnosis of fibrosis >or=F2, >or=F3 and F4 were 0.90, 0.93, and 0.98, respectively. There was a close direct correlation between liver stiffness and HVPG (Pearson coefficient, 0.84; P < 0.001) and the AUC for diagnosis of portal hypertension (HVPG >or=6 mm Hg) was 0.93. Importantly, none of the individuals with liver stiffness below the cutoff value had either bridging fibrosis (F3) or cirrhosis (F4) or significant portal hypertension (HVPG >or=10 mm Hg). In conclusion, determination of liver stiffness is an extremely valuable tool to assess the severity of HCV recurrence after LT and in reducing the need of follow-up liver biopsies.

Hepatic venous pressure gradient identifies patients at risk of severe hepatitis C recurrence after liver transplantation

Liver biopsy is essential in the follow-up of HCV-infected liver transplant recipients. The aim of this study was to prospectively compare percutaneous (PLB) versus transjugular liver biopsy (TLB) in the assessment of liver damage. We also explored the diagnostic value of hepatic venous pressure gradient (HVPG) to identify patients at risk of severe HCV disease recurrence after liver transplantation (LT). One hundred sixteen paired PLB and TLB (with HVPG measurement) were performed 3 or 12 months after LT in 80 patients. Concordance for necroinflammation and fibrosis was fair or good, particularly 1 year after LT (kappa > or = 0.6). At this point, a significant positive association was seen between the median HVPG and the fibrosis stage (2.5 mm Hg for F0; 5 mm Hg for F1, 6 mm Hg for F2, and 11.5 mm Hg for F3; Kruscal-Wallis < 0.001). Despite this strong association, portal hypertension (HVPG > or = 6 mm Hg) was detected in 1 (5%) of 22, 4 (16%) of 25, and 6 (60%) of 10 patients with fibrosis stages 0, 1, and 2, respectively. After a median follow-up of 38 months, clinical decompensation occurred in 15 (19%) of 80 patients. Although the presence of significant fibrosis (F2-F3) 1 year after transplantation was good to predict clinical decompensation (AUC: 0.80), an HVPG of 6 mm Hg or greater was extremely accurate at identifying patients at risk of disease progression (AUC: 0.96). In conclusion, HVPG determination is a valuable tool for follow-up in patients with HCV recurrence after LT.

Correlação entre a contagem de plaquetas no sangue e o gradiente de pressão venosa hepática em pacientes cirróticos

RACIONAL: A medida do gradiente de pressão venosa hepática é o método mais utilizado para a avaliação da pressão portal. Mais recentemente, a contagem de plaquetas no sangue tem sido apontada como um marcador não-invasivo da presença de hipertensão portal. OBJETIVO: Correlacionar a contagem de plaquetas com os valores do gradiente de pressão venosa hepática em uma população de pacientes cirróticos. PACIENTES E MÉTODOS: Foram estudados 83 pacientes com hepatopatia crônica que realizaram estudo hemodinâmico hepático, em período de 6 anos. Os pacientes foram divididos em grupos conforme a classificação de Child-Pugh e todos realizaram endoscopia digestiva alta para constatar a presença de varizes de esôfago, assim como tiveram a contagem sérica de plaquetas determinada. RESULTADOS: O número de plaquetas variou entre 45.000/mm³ e 389.000/mm³, com média 104.099 e desvio-padrão 58.776. O gradiente de pressão venosa apresentou média igual a 15,2 mm Hg e desvio-padrão igual a 6,4 mm Hg, variando de 1 a 29 mm Hg. Realizou-se regressão linear simples para verificar a correlação entre o gradiente de pressão venosa e o número de plaquetas, o que permitiu constatar fraca correlação entre ambos. Embora se tenha observado menor número de plaquetas, à medida que o calibre das varizes aumentava e nos pacientes com maior grau de disfunção hepatocelular - medida pela classificação de Child-Pugh - não se encontrou significância estatística. CONCLUSÃO: A despeito de não haver demonstrado correlação estatística entre o número de plaquetas com o gradiente de pressão venosa hepática e o grau de disfunção hepatocelular, pelas tendências observadas, acredita-se que ambos os fatores podem estar implicados na patogenia da plaquetopenia em pacientes cirróticos.

Fatal variceal rupture after sildenafil use: Report of a case

Sildenafil may increase the risk of variceal bleeding in portal hyptertension by increasing splanchnic blood flow. We report herein the second case of variceal rupture after sildenafil use.

Molecular mechanisms of alcohol-induced hepatic fibrosis

Alcohol abuse is a major cause of liver fibrosis and cirrhosis in developed countries. Before alcoholic liver fibrosis becomes evident, the liver undergoes several stages of alcoholic liver disease including steatosis and steatohepatitis. Although the main mechanisms of fibrogenesis are independent of the etiology of liver injury, alcoholic liver fibrosis is distinctively characterized by a pronounced inflammatory response due to elevated gut-derived endotoxin plasma levels, an augmented generation of oxidative stress with pericentral hepatic hypoxia and the formation of cell-toxic and profibrogenic ethanol metabolites (e.g. acetaldehyde or lipid oxidation products). These factors, based on a complex network of cytokine actions, together result in increased hepatocellular damage and activation of hepatic stellate cells, the key cell type of liver fibrogenesis. Although to date removal of the causative agent, i.e. alcohol, still represents the most effective intervention to prevent the manifestation of alcoholic liver disease, sophisticated molecular approaches are underway, aiming to specifically blunt profibrogenic signaling pathways in liver cells or specifically induce cell death in activated hepatic stellate cells to decrease the scarring of the liver.

Differential expression and localization of nitric oxide synthases in cirrhotic livers of bile duct-ligated rats

Increased vascular nitric oxide (NO) production has been implicated in the pathogenesis of the hyperdynamic circulation in liver cirrhosis. This study investigated the expression of three isoforms of NO synthase (NOS) in rat cirrhotic livers. Cirrhosis was induced by chronic bile duct ligation (BDL). NOS enzyme activity was assessed by L-citrulline generation. Competitive RT-PCR was performed to detect the mRNA levels of NOS. In situ hybridization was done to localize NOS mRNA. Protein expression of NOS was evaluated by Western blotting and immunohistochemistry. The L-citrulline assay showed that constitutive NOS (cNOS) enzymatic activity was decreased, while inducible NOS (iNOS) activity was increased in BDL livers. Both endothelial NOS (eNOS) and neuronal NOS (nNOS) mRNA were detected in BDL and sham rats, but with enhanced expression in BDL rats. eNOS protein was redistributed with less expression in sinusoidal endothelial cells, but the total levels in liver were not changed. nNOS was induced in hepatocytes of BDL rats, in contrast to only a weak signal observed around some blood vessels in sham livers. Intense mRNA and protein expression of iNOS was induced in livers of BDL rats and was localized in hepatocytes, with no or a negligible amount in control livers. In conclusion, iNOS was induced in cirrhotic liver with its activity increased. In contrast, cNOS activity was impaired, regardless of unchanged eNOS protein levels and enhanced nNOS expression. These results suggest that all three types of NOS have a role in cirrhosis, but their expression and regulation are different.

Adenosine A(2A) receptors in portal hypertension: their role in the abnormal response to adenosine of the cranial mesenteric artery in rabbits

1. Adenosine is a regulator of mesenteric vasodilation involved in auto-regulation and post-prandial hyperemia, but the adenosine receptor subtype involved in this relaxant effect is poorly characterized. We have now pharmacologically characterized this receptor in rabbit mesenteric arteries and investigated how this adenosine receptor response changes in portal hypertensive animals since the adenosine response is decreased. 2. The closest non-metabolisable adenosine analogue, 2-chloroadenosine (CADO), the mixed A(1)/A(2) receptor agonist, 5'-ethylcarboxamidoadenosine (NECA), and the selective A(2A) receptor agonist, 2-[4-(2-p-carbonyethyl)phenylamino]-5'-N-ethylcarboxamidoadenosine (CGS 21680) (1 pM -- 1 mM) relaxed noradrenaline pre-contracted arteries with a rank order of potency of CGS 21680 (EC(50)=20 nM) > or = NECA (60 nM)>>CADO (640 nM). 3. The selective A(2A) receptor antagonist, 4-(2-[7-amino-2-(2-furyl)-[1,2,4]-triazolo[2,3-a][1,3,5]-triazin-5-ylamino]ethyl)phenol (ZM 241385, 100 nM), shifted to the right the CADO concentration-response curve. 4. In portal hypertensive animals, there was mainly a decreased potency but also a decreased efficacy of all tested adenosine agonists compared to normal animals. Concomitantly, there was a decreased adenosine plasma level and a decreased binding density of [(3)H]-CGS 21680 and [(3)H]-ZM 241385 to mesenteric artery membranes from portal hypertensive compared to normal rabbits. 5. These results indicate that A(2A) receptor activation is required for the adenosine-induced mesenteric relaxation and that the decreased density of A(2A) receptors may contribute to the decreased relaxation induced by adenosine of mesenteric arteries in portal hypertensive animals.

Circadian variation in portal pressure: appropriate use of non-selective beta blockers in the prevention of variceal bleed

The circadian variation in some biologic functions may have clinical, fiscal and therapeutic implications. The authors discuss circadian variation in portal pressure in cirrhotic patients and nocturnal occurrence of bleeding from varices in these patients. The pathogenesis of the diurnal variation in portal pressure is presented. The authors submit the hypothesis that an optimal dosing regimen for non-selective beta blocker therapy in the prevention of variceal bleed must include an evening dose of beta blocker medication. In studies reporting comparative efficacy of beta blocker therapy with other modalities in the prevention of variceal bleeding, the optimal dosing schedule for beta blocker therapy must be emphasized.

Assessment of portal hypertension in humans

Patients suspected of having portal hypertension (either by clinical history, physical examination, or previous diagnosis) should undergo ultrasonography and upper gastrointestinal endoscopy. Ultrasonography, preferably using the duplex technique, can disclose the patency of the portal venous system, the presence of signs of portal hypertension (splenomegaly, portocollateral vessels, repermeabilization of the umbilical vein, and so forth) and provide additional information about liver, biliary, or pancreatic diseases that may be the cause of portal hypertension. Endoscopy can assess the presence and size of gastroesophageal varices, the appearance of the variceal wall, and the presence and severity of portal hypertensive gastropathy. Patients showing a patent portal vein should have hepatic vein catheterization to evaluate the presence of presinusoidal, sinusoidal, or postsinusoidal portal hypertension. Patients in whom presinusoidal portal hypertension is suspected (those having esophageal varices with an HVPG below 10 mm Hg) should have liver biopsy and percutaneous transhepatic measurement of portal pressure. In sinusoidal portal hypertension, the results of endoscopy and HVPG measurement are decisive for the therapeutic management of the patients. The authors' results indicate that, before starting prophylactic therapy with beta-blockers, all patients should undergo at least an hepatic vein catheterization to assess HVPG; it would be preferable to have a variceal pressure measurement also. These measurements must be repeated 3 to 4 weeks after the final dose of therapy has been reached to assess the risk of variceal bleeding or rebleeding.

Production and release of endothelin-1 from the gut and spleen in portal hypertension due to cirrhosis

This study was aimed to evaluate the source of endothelin-1 (ET-1) in cirrhotic patients. ET-1 is implicated in the pathogenesis of portal hypertension. However, the mechanism and source for increased plasma ET-1 in cirrhotic patients are still obscure. Plasma ET-1 levels in systemic (SV), superior mesenteric (SMV), and splenic venous (SPV) blood were measured in 23 patients with cirrhosis and 8 controls with normal liver. Fourteen removed spleens were immunohistochemically studied for ET-1, CD34, CD68, and CD20. In situ hybridization was done to localize ET-1 messenger RNA (mRNA). In cirrhosis, ET-1 levels in both SMV and SPV were higher than in SV. ET-1 in SV and SPV were significantly higher in cirrhotic patients than in control patients. Three groups of cells in the spleen expressed both protein and mRNA of ET-1: endothelial cells in the sinus, which were also stained for CD34; cells in the germinal center; and cells in the marginal zone of lymphoid sheaths and follicles, which were also stained for CD20 but not for CD34 and CD68. The ET-1 concentration released from the spleen was in parallel with the grade of ET-1 expression in the spleen. The spleen is one of the major sites of ET-1 release in cirrhotic patients. Endothelial cells of the splenic sinus and possibly B lymphocytes in the germinal center and marginal zone of lymphoid sheaths and follicles seem to be the sites of ET-1 production in the spleen.

Terlipressin is more effective in decreasing variceal pressure than portal pressure in cirrhotic patients

BACKGROUND/AIMS

Terlipressin decreases portal pressure. However, its effects on variceal pressure have been poorly investigated. This study investigated the variceal, splanchnic and systemic hemodynamic effects of terlipressin.

METHODS

Twenty cirrhotic patients with esophageal varices grade II-III, and portal pressure > or =12 mmHg were studied. Hepatic venous pressure gradient, variceal pressure and systemic hemodynamic parameters were obtained. After baseline measurements, in a double-blind administration, 14 patients received a 2mg/iv injection of terlipressin and six patients received placebo. The same measurements were repeated 60 min later.

RESULTS

No demographic or biochemical differences were observed in basal condition between groups. Terlipressin produced significant decreases in intravariceal pressure from 20.9+4.9 to 16.3+/-4.7 mmHg (p<0.01, -21+/- 16%), variceal pressure gradient from 18.9+/-4.8 to 13.5+/-6.0 mmHg (p<0.01, -28+/-27%), estimated variceal wall tension from 78+/-29 to 59+/-31 mmHg x mm (p<0.01, -27+/-22%), and hepatic venous pressure gradient from 19.4+/-4.5 to 16.8+/-5 mmHg (p<0.01, -14+/-12%) at 60 min. The change in variceal pressure after 60 min of terlipressin administration was greater than the change in wedge hepatic venous pressure (-4.7 mmHg vs -0.5 mmHg, respectively, p<0.0001). Terlipressin also caused significant decreases in heart rate and cardiac index and increases in mean arterial pressure and peripheral vascular resistance.

CONCLUSIONS

Our results demonstrate that terlipressin produces significant and prolonged decreases in variceal pressure and variceal wall tension and has intrinsic effects on portal pressure and systemic hemodynamics. Variceal pressure provides a better assessment of the effects of terlipressin administration on esophageal varices than hepatic venous pressure gradient.

A non-invasive isotope dilution technique for quantifying hepatic blood flow using radiolabelled red blood cells

Clinically significant changes in hepatic haemodynamics accompany the development of portal hypertension, hepatocellular carcinoma, liver metastases and liver cirrhoses, and after major liver resection. Hepatic blood flow parameters, such as hepatic arterial flow (HAF), hepatic portal flow (HPF), total hepatic blood flow (THBF) and hepatic perfusion index (HPI), are useful adjuncts to the diagnosis of liver pathology, the evaluation of disease progress and prognostication. Here, we describe a non-invasive method that combines the measurement of these parameters in a single study in real time. Red blood cells from eight pigs were labelled with 99Tc(m) using an in-vitro method and re-injected into the pigs. Data acquisition over the heart, lungs, liver and kidneys was started immediately and a blood sample was obtained 15 min post-injection. Hepatic arterial flow was determined from the ratio of the maximum gradients between the integrated time-activity curve of the left ventricle and the first-pass time-activity curve of the liver before the peak of the kidneys time-activity curve. The hepatic perfusion index was determined by comparing the slope of the liver time-activity curve before and after the kidney peak. Hepatic portal flow was determined from the hepatic arterial flow and the hepatic perfusion index, and total hepatic blood flow was determined as the sum of arterial and portal flow. The results were compared against those obtained from a clearance method using 99Tc(m)-DISIDA. The average hepatic perfusion index was 0.38, and the average hepatic arterial flow and hepatic portal flow were 168.3 +/- 52.9 and 274.6 +/- 60.1 ml x min(-1) respectively. The average total hepatic blood flow was 442.8 +/- 53.5 ml x min(-1), while the total hepatic flow determined by 99Tc(m)-DISIDA clearance was 419.7 +/- 62.6 ml x min(-1). No significant difference in total hepatic blood flow was found between the two methods. The results of this study show that it is possible to obtain all hepatic haemodynamics data in a single study using a non-invasive method.

Esophageal varices: current management in children

The treatment of esophageal variceal hemorrhage is still the subject of some controversy. The main causes of portal hypertension in children are portal vein thrombosis or cirrhosis, most commonly caused by biliary atresia. Many treatment options are available including endoscopic, radiographic, and surgical strategies. In general, children with presinusoidal obstructions have preserved hepatic synthetic function, and, therefore, treatment options include endoscopic strategies or portosystemic shunts, each with advocates. For children with advanced liver disease, liver transplantation offers the only chance for cure, so primary treatment of variceal bleeding should be by endoscopic means or transjugular intrahepatic portosystemic shunt (TIPS). Each modality has specific advantages and disadvantages, and treatment recommendations must therefore be tailored to the individual on a case-by-case basis, largely dependent on the expertise and experience of the health care team.

NO overproduction by eNOS precedes hyperdynamic splanchnic circulation in portal hypertensive rats

Chronic high blood flow and the hyperdynamic circulatory syndrome in portal hypertension are associated with endothelial constitutive nitric oxide (NO) synthase (eNOS) upregulation and increased NO release. In portal vein-ligated (PVL) rats the splanchnic circulation is not yet hyperdynamic on day 3 postoperatively. In vitro perfused superior mesenteric arteries (SMAs) of day 3 PVL and sham rats were challenged with increasing flow rates or the alpha-adrenoreceptor agonist methoxamine (30 and 100 microM) before and after incubation with the NO inhibitor, Nomega-nitro-L-arginine (L-NNA, 10(-4) M). Perfusate NO metabolite (NOx) concentrations were measured by chemiluminescence. PVL rats expressed a significant hyporesponsiveness to increases in flow rate or methoxamine that was overcome by incubation with L-NNA. The PVL vasculature showed significantly higher slopes of NOx production vs. flow-induced shear stress, higher increases in perfusate NOx concentration in response to methoxamine, and higher eNOS protein levels (Western blot) compared with sham rats. In conclusion, eNOS-upregulation and increased NO release by the SMA endothelium occur before the development of the hyperdynamic splanchnic circulation, suggesting a primary role of NO in the pathogenesis of arterial vasodilatation.

Enhanced release of nitric oxide in response to changes in flow and shear stress in the superior mesenteric arteries of portal hypertensive rats

Increased nitric oxide (NO) release has been implicated in the pathogenesis of the hyperdynamic circulation in portal hypertension. NOS 3 (eNOS) causes NO release from the endothelium in response to physical stimuli, such as increased blood flow and shear stress. We evaluated the functional activity of the endothelium in the superior mesenteric arterial bed of portal hypertensive rats through direct measurement of NO metabolites (NOx) during changes in flow and shear stress. The in vitro perfusion system (McGregor) was used in sham and portal vein-ligated (PVL) rats. Shear stress was applied gradually to superior mesenteric arterial beds by increasing the perfusion rate. Flow studies were performed serially before and after incubation with either Krebs solution alone or with the NO-inhibitor, NG-monomethyl-L-arginine (L-NMMA). NOx concentrations in the perfusate were measured using chemiluminescence. The slope of NOx release versus flow-induced shear stress was calculated. Before L-NMMA administration, NOx concentrations and release of NO in PVL rats were significantly elevated in comparison with sham rats at flow rates of 32, 40, and 48 mL/min. The slope of NOx production versus shear stress index was significantly higher in PVL than in sham rats. After L-NMMA incubation, the decrease in slope was significantly larger in PVL rats. This study provides direct evidences of an increased NO synthesis by the superior mesenteric arterial vascular endothelium of PVL animals in response to shear stress. The increased NO output in response to shear stress suggests an adaptative mechanism developed by the vascular endothelial cells in response to a chronic increase in flow-mediated shear stress.

Splanchnic hyperemia after liver transplantation in patients with end-stage liver disease

Systemic and splanchnic hemodynamic parameters were evaluated in 12 patients with cirrhosis before and 3 and 6 months after liver transplantation. Results were compared with those obtained in 8 healthy subjects. Three months after liver transplantation recipients had an increase in mean arterial pressure (98 +/- 7 v 78 +/- 9 mmHg; P < .05), an insignificant decrease in cardiac index (3. 4 +/- 0.6 v 4.0 +/- 1.0 L . min-1 . m-2), and a marked increase in peripheral vascular resistance (1,563 +/- 308 v 800 +/- 205 dyne . s . cm-5; P < .05) compared with pretransplantation values. Portal blood flow was also significantly increased (1,494 +/- 200 v 829 +/- 130 mL/min; P < .05). These hemodynamic changes were more pronounced 6 months after transplantation (mean arterial pressure, 100 +/- 8 mmHg; cardiac index, 3.0 +/- 1.0 L . min-1 . m-2; P < .01; peripheral vascular resistance, 1,680 +/- 405 dyne . s . cm-5; portal blood flow, 1,520 +/- 180 mL/min). Systemic hemodynamics 6 months after liver transplantation were similar to those observed in the healthy control group (mean arterial pressure, 95 +/- 6 mmHg; cardiac index, 2.9 +/- 0.9 L . min-1 . m-2; peripheral vascular resistance, 1,480 +/- 380 dyne . s . cm-5). However, portal blood flow was still significantly higher than in healthy controls at 6 months (1,520 +/- 180 v 910 +/- 140 mL/min; P < .05). This study shows that systemic hemodynamics are normalized after liver transplantation. However, an increase in portal blood flow occurs and persists for at least 6 months after liver transplantation. Further studies are needed to clarify the cause of the abnormally high portal flows.

Effects of F-180, a new selective vasoconstrictor peptide, compared with terlipressin and vasopressin on systemic and splanchnic hemodynamics in a rat model of portal hypertension

The present study is aimed at characterizing the portal, splanchnic, and systemic circulatory effects of F-180, a new long-acting analog of vasopressin (VP) with selective effect on the vascular (V1) receptor, both in normal rats and in portal-hypertensive animals. In preliminary vasopressor tests, F-180 was 18 times more potent than terlipressin (TP) (164 +/- 10 IU x mmol(-1) vs. 9.2 +/- 1.2 IU x mmol(-1)) and four times less potent than arginine VP (614 +/- 25 IU x mmol(-1)). F-180 had negligible antidiuretic potency, resulting in vascular selectivity (V1/V2) of 858 compared with 1.0 for VP and 2.2 for TP. In portal-hypertensive rats with partial portal vein ligation (PPVL), the vasopressor effect of F-180 was 19 times that of TP on a molar basis (ED50 F-180: 0.54 vs. TP: 10.02 nmol x kg(-1)). At low doses (0.405 nmol x kg(-1)), F-180 significantly reduced portal pressure (PP) (-13.8% +/- 6.7%) and superior mesenteric artery blood flow (SMABF) (-25.6% +/- 4.5%), whereas TP at 8.10 nmol x kg(-1) was required to achieve comparable splanchnic effects; however, this dose caused a significantly greater increase in mean arterial pressure (MAP) than F-180 at 0.405 nmol x kg(-1) (28.2% +/- 2.7% vs. 8.9% +/- 2.7% at 20 minutes; P < .05). F-180 at 0.405 nmol x kg(-1) had effects on PP and SMABF similar to a 30-minute intravenous infusion of VP at 10 mU x kg(-1) in PPVL rats, but VP caused a significantly greater elevation in systemic vascular resistance (SVR) and MAP, and more pronounced reduction in cardiac index (P < .05).

Role of calcitonin gene-related peptide in the vascular system on the development of the hyperdynamic circulation in conscious cirrhotic rats

BACKGROUND/AIMS

Calcitonin gene-related peptide (CGRP), a potent vasodilator; plays an important role in modulating vascular tone, acting as a noncholinergic nonadrenergic neurotransmitter. The aim of this study was to assess the role of CGRP, present in the vascular system, in the development of the hyperdynamic circulation observed in liver cirrhosis.

METHODS

Two doses of human alpha-CGRP [8-37], a specific antagonist of CGRP, were administered to cirrhotic and controls rats. Hemodynamics were evaluated using radioactive microspheres in conscious animals. To investigate the arterial depressor effect of exogenous CGRP, we constructed a dose-response curve for mean arterial pressure in cirrhotic and control rats by administering human alpha-CGRP.

RESULTS

The administration of high-dose human alpha-CGRP [8-37] (300 nmol.kg body weight-1.min-1) significantly increased both the mean arterial pressure (21 +/- 2 vs. 13 +/- 1%, p < 0.01) and total vascular resistance (76 +/- 5 vs. 54 +/- 5%, p < 0.01) in cirrhotic rats, compared to control rats. The splanchnic hemodynamic effects induced by human alpha-CGRP [8-37] were a significant decrease in percent change of portal venous inflow -42 +/- 3 vs. -33 +/- 3%, p < 0.05) and a significant increase in percent change of splanchnic arterial resistance (110 +/- 9 vs. 76 +/- 5%, p < 0.01) in cirrhotic rats, compared to control rats. Low-dose human alpha-CGRP [8-37] (60 nmol.kg body weight-1. min-1) caused similar hemodynamic changes, but the degree of change was much less than for the high-dose administration. The vascular response to human alpha-CGRP was significantly reduced in cirrhotic rats as compared to controls (ANOVA, p < 0.01). Plasma concentrations of CGRP were significantly elevated in cirrhotic rats.

CONCLUSIONS

CGRP in the vascular system was involved in the modulation of vasodilatation in rats with liver cirrhosis, as demonstrated by the administration of a selective CGRP antagonist and exogenous CGRP.

Pathophysiology and treatment of variceal hemorrhage

Portal hypertension results from increases in portal flow and portal vascular resistance. Factors increasing portal blood flow are predominantly humoral. Resistance to portal flow has a fixed component due to distortion of the vasculature by cirrhotic nodules and a variable component that is related to vasoactive substances. Varices result from an increase in portal pressure. Factors predicting the risk of variceal bleeding include continued alcohol use, poor liver function, large varices, and red wale markings on varices at endoscopy. Octreotide is probably the drug of choice for pharmacologic management of bleeding esophageal varices. Propranolol has an established role in the prevention of variceal hemorrhage, and variceal band ligation may be the preferred endoscopic technique. Transjugular intrahepatic portosystemic shunts have emerged as an important treatment for patients in whom pharmacologic and endoscopic therapies have failed and are an effective bridge to liver transplantation.