Portal hypertension: from bedside to bench

Pathophysiology of ascites: The importance of the intestine. A surgical contribution to the understanding of a medical problem

The understanding of the mechanisms for the development of ascites has evolved over the years, involving the liver, peritoneum, heart, and kidneys as key responsible for its formation. In this article, we review the pathophysiology of ascites formation, introducing the role of the intestine as a major responsible for ascites production through "a game changer" case.

Improved Applicability and Diagnostic Accuracy of the Novel Spleen-Dedicated Transient Elastography Device for High-Risk Esophageal Varices

Spleen stiffness measurement (SSM) by transient elastography (TE) has been repeatedly demonstrated as the reliable way to rule out the presence of high-risk esophageal varices (HRV). We aimed to evaluate and compare novel vs. standard TE-SSM module performance in diagnosing HRV in patients with compensated advanced chronic liver disease (cACLD). This retrospective study included patients with cACLD; blood data, upper digestive endoscopy performed within 3 months of TE, SSM@50Hz and SSM@100Hz were collected. Overall, 112 patients with cACLD were analyzed (75.9% males, average age of 66, 43.7% alcohol-related chronic liver disease, 22.3% metabolic-associated steatotic liver disease, 6.2% viral hepatitis). Reliable SSM was possible in 80.3% and 93.8% of patients by using SSM@50Hz and SSM@100Hz probe, respectively. At the cut-off 41.8 kPa and 40.9 kPa (Youden), SSM@50Hz and SSM@100Hz had AUROCs of 0.746 and 0.752, respectively, for diagnosing HRV (p = 0.71). At the respective cut-offs, sensitivities for HRV were 92.9% and 100%, resulting in misclassification rates of 7.1% and 0% by using SSM@50Hz and SSM@100Hz. SSM reliably excludes HRV in cACLD patients, with measurements below 41 kPa potentially avoiding EGD in around 50% of cases, with minimal risk of HRV omission. SSM@100Hz demonstrated less measurement failures and no HRV misclassification.

A history of research into the physiology of bile, from Hippocrates to molecular medicine

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Ultrasound Pressure Estimation for Diagnosing Portal Hypertension in Patients Undergoing Dialysis for Chronic Kidney Disease

OBJECTIVES

Hepatic venous pressure gradient (HVPG) is considered the standard in quantifying portal hypertension, but can be unreliable in dialysis patients. A noninvasive ultrasound technique, subharmonic-aided pressure estimation (SHAPE), may be a valuable surrogate of these pressure estimates. This study compared SHAPE and HVPG with pathology findings for fibrosis in dialysis patients.

METHODS

This was a subgroup study from an IRB-approved trial that included 20 patients on dialysis undergoing SHAPE examinations of portal and hepatic veins using a modified Logiq 9 scanner (GE, Waukesha, WI), during infusion of Sonazoid (GE Healthcare, Oslo, Norway). SHAPE was compared to HVPG and pathology findings using the Ludwig-Batts scoring system for fibrosis. Logistic regression, ROC analysis, and t-tests were used to compare HVPG and SHAPE with pathological findings of fibrosis.

RESULTS

Of 20 cases, 5 had HVPG values corresponding to subclinical and clinical portal hypertension (≥6 and ≥10 mmHg, respectively) while 15 had normal HVPG values (≤5 mmHg). SHAPE and HVPG correlated moderately (r = 0.45; P = .047). SHAPE showed a trend toward correlating with fibrosis (r = 0.42; P = .068), while HVPG did not (r = 0.18; P = .45). SHAPE could differentiate between mild (stage 0-1) and moderate to severe (stage 2-4) fibrosis (-10.4 ± 4.9 dB versus -5.4 ± 3.2 dB; P = .035), HVPG could not (3.0 ± 0.6 mmHg versus 4.8 ± 0.7 mmHg; P = .30). ROC curves showed a diagnostic accuracy for SHAPE of 80%, while HVPG reached 76%.

CONCLUSION

Liver fibrosis staging in dialysis patients evaluated for portal hypertension appears to be more accurately predicted by SHAPE than by HVPG; albeit in a small sample size.

Detection of liver and spleen stiffness in rats with portal hypertension by two-dimensional shear wave elastography

BACKGROUND

The measurement of liver stiffness (LS) and spleen stiffness (SS) based on ultrasound elastography can be used for non-invasive assessment of portal hypertension (PH). However, there are few studies on the corresponding mechanism of increased spleen stiffness. Our aim was to use two-dimensional shear wave elastrography (2D-SWE) to evaluate the relationship between LS and SS and the severity of PH in rats. And explore the mechanism of the increase of LS and SS in PH.

METHODS

Sixty male Sprague-Dawley rats were randomly divided into portal hypertension (PH group, n = 45) and normal control (NC group, n = 15). At 12 weeks, LS and SS was detected by 2D-SWE in vivo. Related hemodynamic parameters and portal vein pressure (PVP) was measured. Spleen and liver 2D-SWE detection was performed again after sacrifice. Pathological changes were observed.

RESULTS

The SS and LS were increased in PH group (P < 0.05). The SS decreased after sacrifice, and what's more the magnitude of SS decline significantly higher in PH group than in NC group (P < 0.05). The correlation between SS and PVP is stronger than LS (r = 0.624, P < 0.001). SS has positive correlation with indexes of hyperdynamic circulation, but LS was weakly. The correlation between SS and the pathological grade (r = 0.633, P < 0.001) was lower than that in LS (r = 0.905, P < 0.001). Multiple linear regression analysis revealed that SS, portal vein inner diameter (PVD) and splenic vein blood flow velocity (SVV) were significantly associated with PH.

CONCLUSIONS

Spleen and liver measurement by 2D-SWE may be helpful in evaluating PVP. The correlation between SS and PVP is stronger than LS in rats measured by 2D-SWE. Hemodynamic circulation are important in the elevation of SS with portal hypertension. Pathological changes also have a degree of influence, but have more significance for the elevation of LS. SS may be a more effective noninvasive predictor of PH than LS.

Hepatic Vein Contrast-Enhanced Ultrasound Subharmonic Imaging Signal as a Screening Test for Portal Hypertension

BACKGROUND

Portal hypertension is the underlying cause of most complications associated with cirrhosis, with the hepatic venous pressure gradient (HVPG) used for diagnosis and disease progression. Subharmonic imaging (SHI) is a contrast-specific imaging technique receiving at half the transmit frequency resulting in better tissue suppression.

AIMS

To determine whether the presence of optimized SHI signals inside the hepatic vein can be used as a screening test for portal hypertension.

METHODS

This prospective trial had 131 patients undergoing SHI examination of portal and hepatic veins using a modified Logiq 9 scanner (GE, Waukesha, WI). Images acquired after infusion of the ultrasound contrast agent Sonazoid (GE Healthcare, Oslo, Norway) were assessed for the presence of optimized SHI signals in the hepatic vein and compared to the HVPG values obtained as standard of care.

RESULTS

Of 131 cases, 64 had increased HVPG values corresponding to subclinical (n = 31) and clinical (n = 33) portal hypertension (> 5 and > 10 mmHg, respectively), and 67 had normal HVPG values (< 5 mmHg). Two readers performed independent, binary qualitative assessments of the acquired digital clips. Reader one (experienced radiologist) achieved for the subclinical subgroup sensitivity of 98%, specificity of 88%, and ROC area of 0.93 and for the clinical subgroup sensitivity of 100% and specificity of 61%, with an ROC area of 0.74. Reader two (less experienced radiologist) achieved for the subclinical subgroup sensitivity of 77%, specificity of 76%, and ROC area of 0.76 and for the clinical subgroup sensitivity of 88% and specificity of 63%, with an ROC area of 0.70. Readers agreement was of 83% with kappa value of 0.66.

CONCLUSION

The presence of optimized SHI signals inside the hepatic vein can be a qualitative screening test for portal hypertension, which could reduce the need for invasive diagnostic procedures.

Update on New Aspects of the Renin-Angiotensin System in Hepatic Fibrosis and Portal Hypertension: Implications for Novel Therapeutic Options

There is considerable experimental evidence that the renin angiotensin system (RAS) plays a central role in both hepatic fibrogenesis and portal hypertension. Angiotensin converting enzyme (ACE), a key enzyme of the classical RAS, converts angiotensin I (Ang I) to angiotensin II (Ang II), which acts via the Ang II type 1 receptor (AT1R) to stimulate hepatic fibrosis and increase intrahepatic vascular tone and portal pressure. Inhibitors of the classical RAS, drugs which are widely used in clinical practice in patients with hypertension, have been shown to inhibit liver fibrosis in animal models but their efficacy in human liver disease is yet to be tested in adequately powered clinical trials. Small trials in cirrhotic patients have demonstrated that these drugs may lower portal pressure but produce off-target complications such as systemic hypotension and renal failure. More recently, the alternate RAS, comprising its key enzyme, ACE2, the effector peptide angiotensin-(1–7) (Ang-(1–7)) which mediates its effects via the putative receptor Mas (MasR), has also been implicated in the pathogenesis of liver fibrosis and portal hypertension. This system is activated in both preclinical animal models and human chronic liver disease and it is now well established that the alternate RAS counter-regulates many of the deleterious effects of the ACE-dependent classical RAS. Work from our laboratory has demonstrated that liver-specific ACE2 overexpression reduces hepatic fibrosis and liver perfusion pressure without producing off-target effects. In addition, recent studies suggest that the blockers of the receptors of alternate RAS, such as the MasR and Mas related G protein-coupled receptor type-D (MrgD), increase splanchnic vascular resistance in cirrhotic animals, and thus drugs targeting the alternate RAS may be useful in the treatment of portal hypertension. This review outlines the role of the RAS in liver fibrosis and portal hypertension with a special emphasis on the possible new therapeutic approaches targeting the ACE2-driven alternate RAS.

Cirrhotic portal hypertension: From pathophysiology to novel therapeutics

Portal hypertension and bleeding from gastroesophageal varices is the major cause of morbidity and mortality in patients with cirrhosis. Portal hypertension is initiated by increased intrahepatic vascular resistance and a hyperdynamic circulatory state. The latter is characterized by a high cardiac output, increased total blood volume and splanchnic vasodilatation, resulting in increased mesenteric blood flow. Pharmacological manipulation of cirrhotic portal hypertension targets both the splanchnic and hepatic vascular beds. Drugs such as angiotensin converting enzyme inhibitors and angiotensin II type receptor 1 blockers, which target the components of the classical renin angiotensin system (RAS), are expected to reduce intrahepatic vascular tone by reducing extracellular matrix deposition and vasoactivity of contractile cells and thereby improve portal hypertension. However, these drugs have been shown to produce significant off-target effects such as systemic hypotension and renal failure. Therefore, the current pharmacological mainstay in clinical practice to prevent variceal bleeding and improving patient survival by reducing portal pressure is non-selective -blockers (NSBBs). These NSBBs work by reducing cardiac output and splanchnic vasodilatation but most patients do not achieve an optimal therapeutic response and a significant proportion of patients are unable to tolerate these drugs. Although statins, used alone or in combination with NSBBs, have been shown to improve portal pressure and overall mortality in cirrhotic patients, further randomized clinical trials are warranted involving larger patient populations with clear clinical end points. On the other hand, recent findings from studies that have investigated the potential use of the blockers of the components of the alternate RAS provided compelling evidence that could lead to the development of drugs targeting the splanchnic vascular bed to inhibit splanchnic vasodilatation in portal hypertension. This review outlines the mechanisms related to the pathogenesis of portal hypertension and attempts to provide an update on currently available therapeutic approaches in the management of portal hypertension with special emphasis on how the alternate RAS could be manipulated in our search for development of safe, specific and effective novel therapies to treat portal hypertension in cirrhosis.

Can We Add the History of the Nonoperative Therapy of Varices to Other Success Chapters of Modern Medicine?

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Observational study of the microcirculation in patients with liver cirrhosis

BACKGROUND AND AIM

Liver cirrhosis is associated with widespread microcirculatory dysfunction and hemodynamic derangement, which may play a role in the pathogenesis of multiple organ failure. Little is known, however, about the progression of microvascular alterations as the severity of liver disease worsens. Therefore, our aim is to quantify the peripheral systemic microcirculatory changes associated with increasing severity of liver cirrhosis.

METHODS

Forty patients with liver cirrhosis were studied and divided into groups based on Child-Pugh classes A (n = 9), B (n = 18), and C (n = 13) for comparison. Incident dark field imaging was used to evaluate the sublingual microcirculation and near-infrared spectroscopy at the thenar eminence to assess microvascular reactivity and function.

RESULTS

There was no difference in microcirculatory flow index (P = 0.655), heterogeneity index (P = 0.702), or vessel density (P = 0.923) between the different Child-Pugh groups. Microvascular reactivity did not change as the severity of liver disease worsened.

CONCLUSIONS

This study showed no association between peripheral systemic microcirculatory alterations and the severity of liver disease. Further research with larger study cohorts are needed to clarify the relationship between microcirculatory abnormalities and disease progression and to establish if the peripheral microcirculation is affected by the pathophysiology of worsening cirrhosis.

Vascular syndromes in liver cirrhosis

Liver cirrhosis is associated with multiple vascular syndromes affecting almost all body systems. Many of these syndromes are directly related to impaired liver function and sometimes reversible after liver transplantation while others arise secondary to portal hypertension and ascites. Altered expression of angiogenic and vasoactive compounds (most importantly nitric oxide), endothelial dysfunction, dysregulated neurohormonal control, and systemic inflammatory state play differential roles in mediating homeostatic instability and abnormal vasogenic response. Important vascular features encountered in liver disease include portal hypertension, splanchnic overflow, abnormal angiogenesis and shunts, portopulmonary syndrome, hepatopulmonary syndrome, and systemic hyperdynamic circulation. Redistribution of effective circulatory volume deviating from vital organs and pooling in splanchnic circulation is also encountered in liver patients which may lead to devastating outcomes as hepatorenal syndrome. Etiologically, vascular syndromes are not isolated phenomena and vascular dysfunction in one system may lead to the development of another in a different system. This review focuses on understanding the pathophysiological factors underlying vascular syndromes related to chronic liver disease and the potential links among them. Many of these syndromes are associated with high mortality, thus it is crucial to look for early biomarkers for these syndromes and develop novel preventive and therapeutic strategies.

Copeptin as a novel marker predicting prognosis of liver cirrhosis and its major complications

OBJECTIVES

The aim of the work was to assess the level of copeptin as a surrogate marker predicting the severity of liver diseases and its major complications.

PATIENTS AND METHODS

This was a cross-sectional study that included 40 patients and 10 controls and was performed in Tanta University Hospital between June 2016 and November 2016. The studied cases were divided into five groups: group I (10 patients): compensated cirrhosis; group II (10 patients): cirrhosis with gastrointestinal hemorrhage due to portal hypertension; group III (10 patients): cirrhosis with hepatorenal syndrome; group IV (10 patients): cirrhosis with liver cell failure; and group V (10 controls): normal healthy individuals.

RESULTS

Regarding serum copeptin in the studied groups, copeptin showed a significant decrease in group I vs group II' group I vs group III, and group I vs group IV; and there was a significant increase in group II vs group III' group II vs group IV' group II vs control' group III vs control, and group IV vs control. No significance was detected between group I vs control and group III vs group IV.

CONCLUSIONS

Copeptin is a novel marker for the determination of prognosis of liver cirrhosis. There is significant association between serum level of copeptin and complications of liver cirrhosis.

Association Between Changes in Splanchnic Hemodynamics and Risk Factors of Portal Venous System Thrombosis After Splenectomy with Periesophagogastric Devascularization

Background

The purpose of this study was to investigate splanchnic hemodynamic changes and determine an optimal cutoff value for risk factors of portal venous system thrombosis (PVST) after splenectomy with periesophagogastric devascularization (SPD) in cirrhotic patients with esophageal and gastric variceal bleeding (EGVB) and portal hypertension (PH).

Material/Methods

Data on patients who underwent SPD were collected retrospectively from January 2013 to December 2017. Color Doppler ultrasound was performed to detect hemodynamic changes of the hepatic artery, splenic artery, splenic vein, and portal vein in included patients (n=60) and healthy volunteers (n=30). Outcomes were compared between preoperative and postoperative biochemical indicators. The cutoff values for hemodynamics were identified using receiver operating characteristic (ROC) curve analysis, and univariate and multivariate analyses of risk factors of PVST were performed.

Results

In our series, hemodynamic indexes of splenic artery, spleen vein, and portal vein in the study group were significantly higher than that of the control group (P<0.05). Multivariate analysis revealed that the portal vein flow and the internal diameter of the portal vein were significantly correlated with PVST. The ROC analysis revealed that the cutoff points for portal vein flow and internal diameter of the splenic vein and portal vein were ≥1822.32 ml/min, ≥1.37 cm, and ≥1.56 cm, respectively.

Conclusions

SPD is an effective treatment in cirrhotic patients with concomitant EGVB and PH by increasing hepatic artery flow and decreasing portal vein flow. High portal vein flow and wider diameters of the portal vein and splenic vein are important markers of PVST.

Review article: the role of the microcirculation in liver cirrhosis

BACKGROUND

Intrahepatic microvascular derangements and microcirculatory dysfunction are key in the development of liver cirrhosis and its associated complications. While much has been documented relating to cirrhosis and the dysfunction of the microcirculation in the liver parenchyma, far less is known about the state of the extrahepatic microcirculation and the role this may have in the pathogenesis of multiple organ failure in end stage liver cirrhosis.

AIM

To provide an update on the role of the microcirculation in the pathophysiology of cirrhosis and its associated complications and briefly discuss some of the imaging techniques which may be used to directly investigate the microcirculation.

METHODS

A Medline literature search was conducted using the following search terms: 'cirrhosis', 'microcirculation', 'circulation', 'systemic', 'inflammation', 'peripheral', 'hepatorenal' and 'hepatopulmonary'.

RESULTS

Significant heterogeneous microvascular alterations exist in patients with cirrhosis. Data suggest that the systemic inflammation, associated with advanced cirrhosis, induces microcirculatory dysregulation and contributes to haemodynamic derangement. The resultant vasoconstriction and hypoperfusion in the systemic extrahepatic microvasculature, is likely to be instrumental in the pathophysiology of organ failure in decompensated cirrhosis, however the mechanistic action of vasoactive agents used to correct the circulatory disturbance of advanced cirrhosis is poorly understood.

CONCLUSIONS

Further research into the role of the microcirculation in patients with liver cirrhosis, will improve physicians understanding of the pathophysiology of cirrhosis, and may provide a platform for real time evaluation of an individual's microcirculatory response to vasoactive mediators, thus guiding their therapy.

Statins activate the canonical hedgehog-signaling and aggravate non-cirrhotic portal hypertension, but inhibit the non-canonical hedgehog signaling and cirrhotic portal hypertension

Liver cirrhosis but also portal vein obstruction cause portal hypertension (PHT) and angiogenesis. This study investigated the differences of angiogenesis in cirrhotic and non-cirrhotic PHT with special emphasis on the canonical (Shh/Gli) and non-canonical (Shh/RhoA) hedgehog pathway. Cirrhotic (bile duct ligation/BDL; CCl₄ intoxication) and non-cirrhotic (partial portal vein ligation/PPVL) rats received either atorvastatin (15 mg/kg; 7d) or control chow before sacrifice. Invasive hemodynamic measurement and Matrigel implantation assessed angiogenesis in vivo. Angiogenesis in vitro was analysed using migration and tube formation assay. In liver and vessel samples from animals and humans, transcript expression was analyzed using RT-PCR and protein expression using Western blot. Atorvastatin decreased portal pressure, shunt flow and angiogenesis in cirrhosis, whereas atorvastatin increased these parameters in PPVL rats. Non-canonical Hh was upregulated in experimental and human liver cirrhosis and was blunted by atorvastatin. Moreover, atorvastatin blocked the non-canonical Hh-pathway RhoA dependently in activated hepatic steallate cells (HSCs). Interestingly, hepatic and extrahepatic Hh-pathway was enhanced in PPVL rats, which resulted in increased angiogenesis. In summary, statins caused contrary effects in cirrhotic and non-cirrhotic portal hypertension. Atorvastatin inhibited the non-canonical Hh-pathway and angiogenesis in cirrhosis. In portal vein obstruction, statins enhanced the canonical Hh-pathway and aggravated PHT and angiogenesis.

Therapies: Drugs, Scopes and Transjugular Intrahepatic Portosystemic Shunt--When and How?

Variceal bleeding is the most serious complication of portal hypertension. All cirrhotic patients should be screened endoscopically for varices which are present in about 30% of compensated and 60% of decompensated patients at diagnosis. In patients without varices, endoscopy surveillance should be continued every 2 years. Patients with high-risk varices (moderate or large in size, or with red color signs, or in Child-Pugh C patients) should be treated with a nonselective β-blocker to prevent bleeding (propranolol, nadolol or carvedilol). Endoscopic banding ligation is also effective for the prevention of first bleeding, and it is the first choice in patients with contraindications or intolerance to β-blockers. Acute variceal hemorrhage still has a high mortality rate (around 15%) and requires intensive care management and conservative blood transfusion policy. Treatment is based on the combined use of vasoactive drugs, endoscopic band ligation and prophylactic antibiotics. Failures are best managed by transjugular intrahepatic portosystemic shunt (TIPS). Balloon tamponade or specifically designed covered esophageal stents can be used as a bridge to definitive therapy in unstable patients. Early, preemptive TIPS might be the first choice in patients at high risk of failure (Child-Pugh B with active bleeding or Child-Pugh C up to 13 points). Patients surviving a variceal bleeding are at high risk of rebleeding. A combination of β-blockers and endoscopic band ligation is the most effective therapeutic approach. Preliminary data suggest that the addition of simvastatin increases survival in these patients.

Sodium Ferulate Reduces Portal Pressure Through Inhibition of RhoA/Rho-Kinase and Activation of Endothelial Nitric Oxide Synthase in Cirrhotic Rats

BACKGROUND AND AIMS

Recent studies have demonstrated that increased RhoA/Rho-kinase activity and reduced nitric oxide activity have the necessary machinery to induce cirrhosis. However, it is unclear whether this regulates the functions of hepatic stellate cells (HSCs). In this study, we used sodium ferulate (SF) in a cirrhotic rat model and examined its roles in regulating RhoA activation in HSCs and the subsequent effects on contraction of HSCs.

METHODS

Bile duct ligation method was used to induce cirrhosis in rats. Intrahepatic resistance was investigated in in situ perfused livers. Hepatic RhoA, Rho-kinase and eNOS expressions were studied by RT-PCR and Western blot. RhoA pull-down assay and collagen gel contraction assay of HSCs were performed by incubation with SF in the absence or presence of GGPP.

RESULTS

We showed that in cirrhotic liver, SF can efficiently affect RhoA activation via lowering the synthesis of GGPP in HSCs. These actions effectively reduced basal intrahepatic resistance in cirrhotic rats. Our study further suggested that SF effectively decreased Rho-kinase activity and increased activity of eNOS at both the mRNA and protein levels. SF treatment of HSCs reduced RhoA GTP without affecting the total RhoA protein level, and GGPP had the ability to block SF-induced protein expression. Furthermore, SF inhibited the contraction of activated HSCs and this inhibition was efficiently reversed by addition of GGPP.

CONCLUSIONS

SF inhibits hepatic RhoA/Rho-kinase signaling and activates the NO/PKG pathway in cirrhotic rats. This may serve as a mechanism for reducing the contraction of activated HSCs upon SF treatment.

Complications of cirrhosis. A 50 years flashback

In patients with cirrhosis and portal hypertension, it is largely the frequency and severity of complications relating to the diseased liver, degree of portal hypertension and hemodynamic derangement that determine the prognosis. It can be considered as a multiple organ failure that apart from the liver involves the heart, lungs, kidneys, the immune systems and other organ systems. Progressive fibrosis of the liver and subsequent metabolic impairment leads to a systemic and splanchnic arteriolar vasodilatation. With the progression of the disease development of portal hypertension leads to formation of esophageal varices and ascites. The circulation becomes hyperdynamic with cardiac, pulmonary as well as renal consequences for dysfunction and reduced survival. Infections and a changed cardiac function known as cirrhotic cardiomyopathy may be involved in further aggravation of other complications such as renal failure precipitating the hepatorenal syndrome. Patients with end-stage liver disease and related complications as for example the hepatopulmonary syndrome can only radically be treated by liver transplantation.

Management of cirrhotic ascites

The most common complication to chronic liver failure is ascites. The formation of ascites in the cirrhotic patient is caused by a complex chain of pathophysiological events involving portal hypertension and progressive vascular dysfunction. Since ascites formation represents a hallmark in the natural history of chronic liver failure it predicts a poor outcome with a 50% mortality rate within 3 years. Patients with ascites are at high risk of developing complications such as spontaneous bacterial peritonitis, hyponatremia and progressive renal impairment. Adequate management of cirrhotic ascites and its complications betters quality of life and increases survival. This paper summarizes the pathophysiology behind cirrhotic ascites and the diagnostic approaches, as well as outlining the current treatment options. Despite improved medical treatment of ascites, liver transplantation remains the ultimate treatment and early referral of the patient to a highly specialized hepatology unit should always be considered.

Evolution in the understanding of the pathophysiological basis of portal hypertension: How changes in paradigm are leading to successful new treatments

Among the common complication of cirrhosis portal hypertension witnessed a major improvement of prognosis during the past decades. Principally due to the introduction of rational treatments based on new pathophysiological paradigms (concepts of thought) developed in the 1980s. The best example being the use of non-selective beta-blockers and of vasopressin analogs, somatostatin, and its analogs. Further refinement in the knowledge of the molecular mechanisms involved in the regulation of both the splanchnic and hepatic circulation has led to the emergence of new treatments, which are based on evidence that show not only structural but also vasoactive components increase the hepatic vascular resistance, as well as of angiogenesis. This knowledge and future improvements will most likely result in more effective treatment of portal hypertension and effective prevention of its complications in early stages.

Prevention of portal hypertension: from variceal development to clinical decompensation

Pharmacological treatment of portal hypertension (PH) has been exclusively devoted to gastroesophageal varices-related events at different frameworks, including prophylactic, emergency, or preventive therapy. The goals of treatment are to avoid the first bleeding episode, stop active bleeding, and prevent bleeding recurrence, respectively. The objective of preprimary prophylaxis (PPP) is to avoid variceal development, and therefore it necessarily deals with patients with cirrhosis at earlier stages of the disease. At these earlier stages, nonselective beta-blockers (NSBBs) have been ineffective in preventing the development of varices and other complications of PH. Therefore, treatment should not rely on NSBB. It is possible that, at these earlier stages, etiological treatment of liver disease itself could prevent progression of PH. This review will focus mainly on early treatment of PH, because, if successful, it may translate into histological-hemodynamic improvements, avoiding not only variceal development, but also other PH-related complications, such as ascites and portosystemic encephalopathy. Moreover, the advent of new therapies may allow not only the prevention of the complications of PH, but also the chance of a substantial degree of regression in the cirrhotic process, with the possible prevention of hepatocellular carcinoma (HCC).

Hepatic hemodynamic changes during liver transplantation: A review

Liver transplantation is performed in the recent decades with great improvements not only technically but also conceptually. However, there is still lack of consensus about the optimal hemodynamic characteristics during liver transplantation. The representative hemodynamic parameters include portal vein pressure, portal vein flow, and hepatic venous pressure gradient; however, there are still others potential valuable parameters, such as total liver inflow and hepatic artery flow. All the parameters are correlated closely and some internal modulating mechanisms, like hepatic arterial buffer response, occur to maintain stable hepatic inflow. To distinguish the unique importance of each hepatic and systemic parameter in different states during liver transplantation, we reviewed the published data and also conducted two transplant cases with different surgical strategies applied to achieve ideal portal inflow and pressure.

Cardiac and proinflammatory markers predict prognosis in cirrhosis

BACKGROUND & AIMS

Inflammation and cardiac dysfunction plays an important role in the development of complications leading to increased mortality in patients with cirrhosis. Novel cardiac markers such as prohormone of ANP (proANP), copeptin and high-sensitivity troponin T (hs-TnT) and proinflammatory markers including soluble urokinase-type plasminogen activator receptor (suPAR) and high-sensitive C-reactive protein (hs-CRP) are related to these complications. We aimed to investigate if cardiac and proinflammatory markers are related to severity of liver disease, cardiac and haemodynamic changes, and long-term survival.

METHODS

One hundred and ninety-three stable cirrhotic patients (Child class: A = 46; B = 97; C = 50) had a full haemodynamic investigation performed with measurement of splanchnic and systemic haemodynamics and measurement of circulating levels of proBNP, proANP, copeptin, hs-TnT, LBP, IL 6, IL 8, IP 10, VEGF, hs-CRP and suPAR.

RESULTS

Soluble urokinase-type plasminogen activator receptor soluble urokinase-type plasminogen activator receptor, hs-CRP, and hs-TnT were significantly different throughout the Child classes (P < 0.01; P < 0.01; P < 0.02). All markers except copeptin correlated with indicators of disease severity in cirrhosis; ProANP and suPAR correlated with hepatic venous pressure gradient (r = 0.24 and r = 0.34; P < 0.001) and systemic vascular resistance (r = -0.24 and r = -0.33; P < 0.001). Cardiac (proANP, hs-TnT; P < 0.01) and proinflammatory (hs-CRP, suPAR; P < 0.05) markers were associated with mortality in a univariate Cox analysis, however, the strongest predictors of mortality in a multivariate Cox analysis were hs-TnT, ascites and hepatic venous pressure gradient (reg.coeff.: 0.34, P < 0.001; 0.16, P < 0.001; 0.06, P = 0.04).

CONCLUSION

Markers of cardiac dysfunction and inflammation are significantly associated with disease severity, degree of portal hypertension and survival in cirrhosis. In particular, hs-TnT and suPAR seem to contain prognostic information.

Pioglitazone decreases portosystemic shunting by modulating inflammation and angiogenesis in cirrhotic and non-cirrhotic portal hypertensive rats

BACKGROUND & AIMS

Development of the portal-hypertensive syndrome is mediated by splanchnic inflammation and neoangiogenesis. Since peroxisome proliferator-activated receptor gamma (PPARγ) agonists like pioglitazone (PIO) regulate inflammatory response and inhibit angiogenesis in endothelial cells, we evaluated PIO as treatment for experimental portal hypertension.

METHODS

PIO (10 mg/kg) or vehicle (VEH) was administered from day 21-28 after bile duct ligation (BDL), from day 0-7 after partial portal vein ligation (PPVL) or sham-operation (SO), respectively. After treatment, systemic hemodynamics, splanchnic blood flow (SMABF), portal pressure (PP), and portosystemic shunting (PSS) were assessed. Splanchnic and hepatic tissues were analyzed for angiogenic and inflammatory markers.

RESULTS

BDL and PPVL showed significantly increased PP, SMABF, and PSS compared to SO-VEH rats. While PIO treatment did not decrease PP or SMABF, PSS was significantly reduced both in cirrhotic (BDL-VEH: 71% to BDL-PIO: 41%; p<0.001) and non-cirrhotic (PPVL-VEH: 62% to PPVL-PIO: 40%; p=0.041) rats. PIO (10 μM, in vitro) inhibited endothelial cell migration and significantly increased PPARγ activity in vivo. In BDL rats, PIO decreased hepatic mRNA levels of PPARγ (p=0.01) and PlGF (p=0.071), and splanchnic mRNA expression of PPARγ (p=0.017), PDGFβ (p=0.053) and TNFα (p=0.075). Accordingly, splanchnic protein expression of PPARγ (p=0.032), VEGFR2 (p=0.035), CD31 (p=0.060) and PDGFβ (p=0.066) were lower in BDL-PIO vs. BDL-VEH animals. In PPVL rats, PIO treatment decreased splanchnic gene expression of Ang2 (-12.4 fold), eNOS (-9.3 fold), PDGF (-7.0 fold), PlGF (-11.9 fold), TGFb (-8.3 fold), VEGF-A (-11.3 fold), VEGFR1 (-5.9 fold), IL1b (-14.4 fold), and IL6 (-9.6 fold).

CONCLUSIONS

Pioglitazone treatment decreases portosystemic shunting via modulation of splanchnic inflammation and neoangiogenesis. Pioglitazone should be assessed for potential beneficial effects in patients with portosystemic collaterals due to portal hypertension.

Monitoring and managing hepatic disease in anaesthesia

Patients with liver disease have multisystem organ dysfunction that leads to physiological perturbations ranging from hyperbilirubinaemia of no clinical consequence to severe coagulopathy and metabolic disarray. Patient-specific risk factors, clinical scoring systems, and surgical procedures stratify perioperative risk for these patients. The anaesthetic management of patients with hepatic dysfunction involves consideration of impaired drug metabolism, hyperdynamic circulation, perioperative hypoxaemia, bleeding, thrombosis, and hepatic encephalopathy.

Experimental liver fibrosis research: update on animal models, legal issues and translational aspects

Liver fibrosis is defined as excessive extracellular matrix deposition and is based on complex interactions between matrix-producing hepatic stellate cells and an abundance of liver-resident and infiltrating cells. Investigation of these processes requires in vitro and in vivo experimental work in animals. However, the use of animals in translational research will be increasingly challenged, at least in countries of the European Union, because of the adoption of new animal welfare rules in 2013. These rules will create an urgent need for optimized standard operating procedures regarding animal experimentation and improved international communication in the liver fibrosis community. This review gives an update on current animal models, techniques and underlying pathomechanisms with the aim of fostering a critical discussion of the limitations and potential of up-to-date animal experimentation. We discuss potential complications in experimental liver fibrosis and provide examples of how the findings of studies in which these models are used can be translated to human disease and therapy. In this review, we want to motivate the international community to design more standardized animal models which might help to address the legally requested replacement, refinement and reduction of animals in fibrosis research.

Terutroban, a TP-receptor antagonist, reduces portal pressure in cirrhotic rats

Increased production of vasoconstrictive prostanoids, such as thromboxane A2 (TXA2 ), contributes to endothelial dysfunction and increased hepatic vascular tone in cirrhosis. TXA2 induces vasoconstriction by way of activation of the thromboxane-A2 /prostaglandin-endoperoxide (TP) receptor. This study investigated whether terutroban, a specific TP receptor blocker, decreases hepatic vascular tone and portal pressure in rats with cirrhosis due to carbon tetrachloride (CCl4 ) or bile duct ligation (BDL). Hepatic and systemic hemodynamics, endothelial dysfunction, liver fibrosis, hepatic Rho-kinase activity (a marker of hepatic stellate cell contraction), and the endothelial nitric oxide synthase (eNOS) signaling pathway were measured in CCl4 and BDL cirrhotic rats treated with terutroban (30 mg/kg/day) or its vehicle for 2 weeks. Terutroban reduced portal pressure in both models without producing significant changes in portal blood flow, suggesting a reduction in hepatic vascular resistance. Terutroban did not significantly change arterial pressure in CCl4 -cirrhotic rats but decreased it significantly in BDL-cirrhotic rats. In livers from CCl4 and BDL-cirrhotic terutroban-treated rats, endothelial dysfunction was improved and Rho-kinase activity was significantly reduced. In CCl4 -cirrhotic rats, terutroban reduced liver fibrosis and decreased alpha smooth muscle actin (α-SMA), collagen-I, and transforming growth factor beta messenger RNA (mRNA) expression without significant changes in the eNOS pathway. In contrast, no change in liver fibrosis was observed in BDL-cirrhotic rats but an increase in the eNOS pathway.

CONCLUSION

Our data indicate that TP-receptor blockade with terutroban decreases portal pressure in cirrhosis. This effect is due to decreased hepatic resistance, which in CCl4 -cirrhotic rats was linked to decreased hepatic fibrosis, but not in BDL rats, in which the main mediator appeared to be an enhanced eNOS-dependent vasodilatation, which was not liver-selective, as it was associated with decreased arterial pressure. The potential use of terutroban for portal hypertension requires further investigation.

Diffusion-weighted imaging (DWI) of the spleen in patients with liver cirrhosis and portal hypertension

OBJECTIVE

The purpose of this study was to assess the influence of liver cirrhosis and portal hypertension on diffusion coefficients of the spleen.

MATERIAL AND METHODS

We retrospectively evaluated 50 patients with liver cirrhosis and 50 patients without any history of liver disease who underwent magnetic resonance imaging of the upper abdomen, including echo planar diffusion-weighted imaging using b values of 50, 300 and 600mm(2)/s. Spleen apparent diffusion coefficient (ADC), liver ADC, muscle ADC and normalized spleen ADC (defined as the ratio of spleen ADC to muscle ADC) were compared between cirrhotic patients and patients in the control group and correlated with Child-Pugh stages. Reproducibility was assessed by measuring interclass correlation coefficient (n=11). Additionally, in eight patients, ADC measurements were performed 1 day before and 3 days after transjugular intrahepatic portosystemic shunt (TIPSS) implantation.

RESULTS

Compared with control subjects, patients with cirrhosis and portal hypertension had significantly higher spleen ADCs (P=.0001). There was a statistically significant correlation between Child-Pugh grade and spleen ADC (Pearson correlation coefficient, observer 1 r=0.6, P=.0001; observer 2 r=0.5, P=.0001). After TIPSS implantation, we observed a reduction in spleen ADC values. Spleen ADC measurements showed a high reproducibility (interclass correlation coefficient 0.75, P=.001).

CONCLUSION

Our data suggest that different stages of liver cirrhosis and portal hypertension correlate with ADC values of the spleen. Furthermore, ADC values of the spleen decrease after TIPSS implantation. Further studies are required to understand the potential clinical values of these observations.

A feasibility study to evaluate splanchnic arterial and venous hemodynamics by flow-sensitive 4D MRI compared with Doppler ultrasound in patients with cirrhosis and controls

PURPOSE

To evaluate the feasibility of time-resolved flow-sensitive four-dimensional (4D) MRI for the visualization and quantification of splanchnic arterial and portal venous hemodynamics in patients with cirrhosis and in controls.

MATERIALS AND METHODS

We applied flow-sensitive 4D MRI to evaluate arterial and portal venous three-dimensional blood flow in patients with advanced liver cirrhosis (n=5) and in healthy controls (n=10) using 3T MRI (spatial resolution=1.7×2.1×2.4 mm, temporal resolution=62.4 ms). The qualitative flow was analyzed using three-dimensional streamlines and time-resolved particle traces. Retrospective flow was quantified in nine predefined anatomic regions evaluating maximum and mean velocities, the flow volume, the vessel lumen area, pulsatility indices, and resistance indices. Doppler ultrasound (US) was our reference standard.

RESULTS

Flow-sensitive 4D MRI visualized liver hemodynamics successfully in 91% of patients and 96% of volunteers with limitations for the patients' extrahepatic vessels (one case of splenic and superior mesenteric veins each) and intrahepatic portal vein branches (in five vessels). Healthy control individuals revealed reduced velocities and larger vessel areas in MRI than in Doppler US. We found no significant differences in the flow volume, pulsatility indices, and resistance indices on comparing MRI with US. Regional flow quantification within the splanchnic system of healthy volunteers and liver cirrhosis patients revealed an increase in the inflow (up to 65%), but a decrease in the patients' outflow (up to 37%).

CONCLUSION

Flow-sensitive 4D MRI is feasible for profound evaluation of arterial and portal venous hemodynamics in liver cirrhosis patients, providing additional information on the pathophysiology of the altered splanchnic system.

Interaction between NO and COX pathways modulating hepatic endothelial cells from control and cirrhotic rats

Reduced intrahepatic nitric oxide (NO) bioavailability and increased cyclooxygenase-1 (COX-1)-derived vasoconstrictor prostanoids modulate the hepatic vascular tone in cirrhosis. We aimed at investigating the reciprocal interactions between NO and COX in the hepatic endothelium of control and cirrhotic rats. NO bioavailability (DAF-FM-DA staining), superoxide (O₂⁻) content (DHE staining), prostanoid production (PGI₂ and TXA₂ by enzyme immunoassays) as well as COX expression (Western Blot), were determined in hepatic endothelial cells (HEC) from control and cirrhotic rats submitted to different experimental conditions: COX activation, COX inhibition, NO activation and NO inhibition. In control and cirrhotic HEC, COX activation with arachidonic acid reduced NO bioavailability and increased O₂⁻ levels. These effects were abolished by pre-treating HEC with the COX inhibitor indomethacin. In control, but not in cirrhotic HEC, scavenging of O₂⁻ by superoxide dismutase (SOD) incubation partially restored the decrease in NO bioavailability promoted by COX activation. NO supplementation produced a significant and parallel reduction in PGI₂ and TXA₂ production in control HEC, whereas it only reduced TXA₂ production in cirrhotic HEC. By contrast, in control and cirrhotic HEC, NO inhibition did not modify COX expression or activity. Our results demonstrate that NO and COX systems are closely interrelated in HEC. This is especially relevant in cirrhotic HEC where COX inhibition increases NO bioavailability and NO supplementation induces a reduction in TXA₂. These strategies may have beneficial effects ameliorating the vasoconstrictor/vasodilator imbalance of the intrahepatic circulation of cirrhotic livers.

Abnormal splenic artery diameter/hepatic artery diameter ratio in cirrhosis-induced portal hypertension

AIM: To determine an optimal cutoff value for abnormal splenic artery diameter/proper hepatic artery diameter (S/P) ratio in cirrhosis-induced portal hypertension.

METHODS: Patients with cirrhosis and portal hypertension (n = 770) and healthy volunteers (n = 31) underwent volumetric computed tomography three-dimensional vascular reconstruction to measure the internal diameters of the splenic artery and proper hepatic artery to calculate the S/P ratio. The cutoff value for abnormal S/P ratio was determined using receiver operating characteristic curve analysis, and the prevalence of abnormal S/P ratio and associations between abnormal S/P ratio and major complications of portal hypertension were studied using logistic regression.

RESULTS: The receiver operating characteristic analysis showed that the cutoff points for abnormal splenic artery internal diameter and S/P ratio were > 5.19 mm and > 1.40, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value were 74.2%, 45.2%, 97.1%, and 6.6%, respectively. The prevalence of an abnormal S/P ratio in the patients with cirrhosis and portal hypertension was 83.4%. Patients with a higher S/P ratio had a lower risk of developing ascites [odds ratio (OR) = 0.708, 95%CI: 0.508-0.986, P = 0.041] and a higher risk of developing esophageal and gastric varices (OR = 1.483, 95%CI: 1.010-2.175, P = 0.044) and forming collateral circulation (OR = 1.518, 95%CI: 1.033-2.230, P = 0.034). After splenectomy, the portal venous pressure and maximum and mean portal venous flow velocities were reduced, while the flow rate and maximum and minimum flow velocities of the hepatic artery were increased (P < 0.05).

CONCLUSION: The prevalence of an abnormal S/P ratio is high in patients with cirrhosis and portal hypertension, and it can be used as an important marker of splanchnic hemodynamic disturbances.

Gamna-Gandy bodies of the spleen detected with susceptibility weighted imaging: maybe a new potential non-invasive marker of esophageal varices

Background/Objectives

Portal hypertension (PH) is a clinical sequelae of liver cirrhosis, and bleeding from esophageal varices (EV) is a serious complication of PH with significant morbidity and mortality. The aims of this study were to assess the ability of 2D multislice breath-hold susceptibility weighted imaging (SWI) to detect Gamna-Gandy bodies (GGBs) in the spleens of patients with PH and to evaluate the potential role of GGB number as a non-invasive marker of PH and EV.

Materials and Methods

T1-, T2- and T2^*- weighted imaging and SWI were performed on 135 patients with PH and on 37 control individuals. Platelet counts were collected from all PH patients. Two radiologists analyzed all magnetic resonance imaging (MRI) data, and measured the portal vein diameter, splenic index (SI), and platelet count/spleen diameter ratio. The numbers of patients with GGBs in the spleen were determined, and the numbers of GGB were counted in the four MRI sequences in GGB-positive patients. The portal vein diameter, SI, platelet count, and platelet count/spleen diameter ratio of control individuals were compared with those of GGB-negative and GGB-positive patients on SWI images. The correlations among GGB numbers, the portal vein diameter, the SI, the platelet count, and the platelet count/spleen diameter ratio were analyzed.

Results

The GGB detection rate and the detected GGB number by using SWI were significantly greater than those by using T1-, T2-, and T2*- weighted images. The number of GGBs in the SWI images correlated positively with the portal vein diameter and SI and correlated negatively with the platelet count and platelet count/spleen diameter ratio.

Conclusion

SWI provided more accurate information of GGBs in patients with PH. The number of GGB may be a non-invasive predictor of improving the selection for endoscopic screening of PH patients at risk of EV.

Insulin resistance in patients with cirrhosis and portal hypertension

Insulin resistance (IR) is involved in the pathogenesis of endothelial dysfunction and is also present in patients with cirrhosis. Intrahepatic endothelial dysfunction plays a major role, increasing hepatic vascular resistance and promoting portal hypertension (PH). In addition, β-adrenergic agonists and insulin share several intracellular signaling pathways. Thus IR may influence the response to β-blockers. This study aimed at evaluating the relationship between IR and hepatic hemodynamics in patients with cirrhosis and with the portal pressure response to acute β-blockade. Forty-nine patients with cirrhosis and PH were included. Hepatic and systemic hemodynamics were measured, and IR was estimated by using the updated homeostasis model assessment (HOMA)-2 index. Patients with HOMA-2 > 2.4 were considered IR. In patients with hepatic venous pressure gradient (HVPG) ≥ 10 mmHg) [clinically significant PH (CSPH)], hemodynamic measurements were performed again 20 min after intravenous propranolol. Mean HOMA-2 index was 3 ± 1.4. Fifty-seven percent of patients had IR. A weak correlation between HOMA-2 index and HVPG was observed. Eighty-six percent of patients had CSPH. HOMA-2 index was an independent predictor of CSPH. However, in patients with CSPH, the correlation between HOMA-2 index and HVPG was lost. HVPG, but not IR, predicted the presence of esophageal varices. Response to propranolol was not different between patients with or without IR. In nondiabetic patients with cirrhosis, HOMA-2 index is directly associated with the presence of CSPH and indirectly with varices, but does not allow either grading HVPG or predicting its response to propranolol.

Diagnosing and monitoring cirrhosis: Liver biopsy, hepatic venous pressure gradient and elastography

In this review we summarize the role of liver biopsy, transient elastography and hepatic venous pressure gradient (HVPG) in the diagnosis and monitoring of patients with liver cirrhosis. Transient elastography is useful for the non-invasive diagnosis of cirrhosis, but relevant information is lost if it is used as a dichotomous test. The development of clinically significant portal hypertension (defined as a hepatic venous pressure gradient ≥ 10 mmHg) is associated with the development of varices and decompensation and it is something that it is worth testing for. Transient elastography has some value for the prediction of clinically significant portal hypertension, but a large proportion of patients have non-diagnostic values. It has also some value for the diagnosis of varices, but non-invasive markers cannot substitute endoscopic screening in cirrhosis. Better dynamic, easily repeatable non-invasive tools are needed to monitor compensated cirrhosis.

Spironolactone lowers portal hypertension by inhibiting liver fibrosis, ROCK-2 activity and activating NO/PKG pathway in the bile-duct-ligated rat

OBJECTIVE

Aldosterone, one of the main peptides in renin angiotensin aldosterone system (RAAS), has been suggested to mediate liver fibrosis and portal hypertension. Spironolactone, an aldosterone antagonist, has beneficial effect on hyperdynamic circulation in clinical practice. However, the mechanisms remain unclear. The present study aimed to investigate the role of spionolactone on liver cirrhosis and portal hypertension.

METHODS

Liver cirrhosis was induced by bile duct ligation (BDL). Spironolactone was administered orally (20 mg/kg/d) after bile duct ligation was performed. Liver fibrosis was assessed by histology, Masson's trichrome staining, and the measurement of hydroxyproline and type I collagen content. The activation of HSC was determined by analysis of alpha smooth muscle actin (α-SMA) expression. Protein expressions and protein phosphorylation were determined by immunohistochemical staining and Western blot analysis, Messenger RNA levels by quantitative real time polymerase chain reaction (Q-PCR). Portal pressure and intrahepatic resistance were examined in vivo.

RESULTS

Treatment with spironolactone significantly lowered portal pressure. This was associated with attenuation of liver fibrosis, intrahepatic resistance and inhibition of HSC activation. In BDL rat liver, spironolactone suppressed up-regulation of proinflammatory cytokines (TNFα and IL-6). Additionally, spironolactone significantly decreased ROCK-2 activity without affecting expression of RhoA and Ras. Moreover, spironolactone markedly increased the levels of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS and the activity of NO effector-protein kinase G (PKG) in the liver.

CONCLUSION

Spironolactone lowers portal hypertension by improvement of liver fibrosis and inhibition of intrahepatic vasoconstriction via down-regulating ROCK-2 activity and activating NO/PKG pathway. Thus, early spironolactone therapy might be the optional therapy in cirrhosis and portal hypertension.

The effects of sorafenib on the portal hypertensive syndrome in patients with liver cirrhosis and hepatocellular carcinoma--a pilot study

BACKGROUND

Increased intrahepatic vascular resistance and hyperperfusion in the splanchnic circulation are the principal mechanisms leading to portal hypertension in cirrhosis. Several preclinical studies have demonstrated a beneficial effect of the multikinase inhibitor sorafenib on the portal hypertensive syndrome.

AIM

To investigate the effect of sorafenib on hepatic venous pressure gradient (HVPG), systemic hemodynamics and intrahepatic mRNA expression of proangiogenic, profibrogenic and proinflammatory genes.

METHODS

Patients with liver fibrosis/cirrhosis and hepatocellular carcinoma were treated with sorafenib 400 mg b.d. HVPG measurement and transjugular liver biopsy were performed at baseline and at week 2. Changes in HVPG and intrahepatic mRNA expression of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), RhoA, tumour necrosis factor-alpha (TNF-α) and placental growth factor (PlGF) were evaluated.

RESULTS

Thirteen patients (m/f = 12/1; Child-Pugh class A/B = 10/3) were included. The most common aetiology of liver disease was alcohol consumption (n = 7). Eleven patients had an elevated portal pressure, including eight patients with clinically significant portal hypertension. A significant decrease of HVPG (≥ 20% from baseline) was observed in four subjects. In HVPG responders, we observed mRNA downregulation of VEGF, PDGF, PlGF, RhoA kinase and TNF-α, while no substantial mRNA decrease was found in nonresponders in any of the five genes. In two of the four HVPG responders we observed a dramatic (43-85%) mRNA decrease of all five investigated genes.

CONCLUSION

Larger controlled clinical trials are needed to demonstrate any potential beneficial effect of sorafenib on portal hypertension in patients with cirrhosis.

Hepato-systemic gradient of carbon monoxide in cirrhosis

BACKGROUND AND AIMS

Experimental data suggest that in liver cirrhosis splanchnic and systemic vasculature exhibit marked endothelial Carbon monoxide (CO) overproduction, while recent data demonstrated heme oxygenase (HO) hyperactivity in the liver of rats with cirrhosis. No data are so far available on CO levels in the hepatic veins of cirrhotic patients. We aimed at evaluating whether plasma CO levels differ between systemic (peripheral vein) and hepatic (hepatic vein) circulation in patients with viral cirrhosis with and without ascites.

METHODS

We enrolled 31 consecutive non-smoking in- or outpatients with liver cirrhosis. We measured wedge (occluded, WHVP) and free hepatic venous pressures (FHVP) and hepatic-vein pressure gradient (HVPG) was the calculated. Plasma level of NO and plasma CO concentration were determined both in peripheral vein and in the hepatic vein in cirrhotics.

RESULTS

In cirrhotic patients plasma CO levels were significantly higher in the hepatic vein (16.66±10.71 p.p.m.) than in the peripheral vein (11.71±7.00 p.p.m). Plasma NO levels were significantly higher in peripheral vein (97.02±21.11 μmol/ml) than in the hepatic vein (60.76±22.93 μmol/ml).

CONCLUSIONS

In patients with liver cirrhosis we documented a hepato-systemic CO gradient as inferred by the higher CO values in the hepatic vein than in the peripheral vein. In cirrhotic patients, CO and NO exhibit opposite behavior in the liver, while both molecules show increased values in the systemic circulation. It can be speculated that increased intra-hepatic CO levels might represent a counterbalancing response to reduced NO intra-hepatic levels in human liver cirrhosis.

Insulin resistance and liver microcirculation in a rat model of early NAFLD

BACKGROUND & AIMS

Insulin contributes to vascular homeostasis in peripheral circulation, but the effects of insulin in liver microvasculature have never been explored. The aim of this study was to assess the vascular effects of insulin in the healthy and fatty liver.

METHODS

Wistar rats were fed a control or a high fat diet (HFD) for 3days, while treated with a placebo, the insulin-sensitizer metformin, or the iNOS inhibitor 1400W. Vascular responses to insulin were evaluated in the isolated liver perfusion model. Insulin sensitivity at the sinusoidal endothelium was tested by endothelium-dependent vasodilation in response to acetylcholine in the presence or absence of insulin and by the level of liver P-eNOS after an insulin injection.

RESULTS

Rats from the HFD groups developed liver steatosis. Livers from the control group showed a dose-dependent hepatic vasodilation in response to insulin, which was blunted in livers from HFD groups. Metformin restored liver vascular insulin-sensitivity. Pre-treatment with insulin enhanced endothelium-dependent vasodilation of the hepatic vasculature and induced hepatic eNOS phosphorylation in control rats but not in HFD rats. Treatment with metformin or 1400W restored the capacity of insulin to enhance endothelium dependent vasodilation and insulin induced eNOS phosphorylation in HFD rats.

CONCLUSIONS

The administration of a HFD induces insulin resistance in the liver sinusoidal endothelium, which is mediated, at least in part, through iNOS upregulation and can be prevented by the administration of metformin. Insulin resistance at the hepatic vasculature can be detected earlier than inflammation or any other sign of advanced NALFD.

Lack of a correlation between portal vein flow and pressure: toward a shared interpretation of hemodynamic stress governing inflow modulation in liver transplantation

The portal vein flow (PVF), portal vein pressure (PVP), and hepatic venous pressure gradient (HVPG) were prospectively assessed to explore their relationships and to better define hyperflow and portal hypertension (PHT) during liver transplantation (LT). Eighty-one LT procedures were analyzed. No correlation between PVF and PVP was observed. Increases in the central venous pressure (CVP) were transmitted to the PVP (58%, range = 25%-91%, P = 0.001). Severe PHT (HVPG ≥ 15 mm Hg) showed a significant reciprocal association with high PVF (P = 0.023) and lower graft survival (P = 0.04). According to this initial experience, an HVPG value ≥ 15 mm Hg is a promising tool for the evaluation of hemodynamic stress potentially influencing outcomes. An algorithm for graft inflow modulation based on flows, gradients, and systemic hemodynamics is provided. In conclusion, the evaluation of PHT severity with PVP could be delusive because of the influence of CVP. PVF and PVP do not correlate and should not be used individually to assess hyperflow and PHT during LT.

Portal hypertension: diagnosis and management with particular reference to variceal hemorrhage

Portal hypertension is a cause a major luminal gut hemorrhage, most often from esophageal varices. Identification of those with varices, and administration of therapies to reduce the likelihood of initial bleeding improve patient outcomes. Beta blocker therapy or variceal band ligation are most often used in this context. Management of acute variceal hemorrhage (including routine use of antibiotics) is followed by initiating strategies to reduce the frequency of recurrent bleeding. Mortality from portal hypertensive bleeding has been diminished by use of these interventions.

Prospective evaluation of intraoperative hemodynamics in liver transplantation with whole, partial and DCD grafts

The interaction of systemic hemodynamics with hepatic flows at the time of liver transplantation (LT) has not been studied in a prospective uniform way for different types of grafts. We prospectively evaluated intraoperative hemodynamics of 103 whole and partial LT. Liver graft hemodynamics were measured using the ultrasound transit time method to obtain portal (PVF) and arterial (HAF) hepatic flow. Measurements were recorded on the native liver, the portocaval shunt, following reperfusion and after biliary anastomosis. After LT HAF and PVF do not immediately return to normal values. Increased PVF was observed after graft implantation. Living donor LT showed the highest compliance to portal hyperperfusion. The amount of liver perfusion seemed to be related to the quality of the graft. A positive correlation for HAF, PVF and total hepatic blood flow with cardiac output was found (p = 0.001). Portal hypertension, macrosteatosis >30%, warm ischemia time and cardiac output, independently influence the hepatic flows. These results highlight the role of systemic hemodynamic management in LT to optimize hepatic perfusion, particularly in LDLT and split LT, where the highest flows were registered.

Physiopathology of splanchnic vasodilation in portal hypertension

In liver cirrhosis, the circulatory hemodynamic alterations of portal hypertension significantly contribute to many of the clinical manifestations of the disease. In the physiopathology of this vascular alteration, mesenteric splanchnic vasodilation plays an essential role by initiating the hemodynamic process. Numerous studies performed in cirrhotic patients and animal models have shown that this splanchnic vasodilation is the result of an important increase in local and systemic vasodilators and the presence of a splanchnic vascular hyporesponsiveness to vasoconstrictors. Among the molecules and factors known to be potentially involved in this arterial vasodilation, nitric oxide seems to have a crucial role in the physiopathology of this vascular alteration. However, none of the wide variety of mediators can be described as solely responsible, since this phenomenon is multifactorial in origin. Moreover, angiogenesis and vascular remodeling processes also seem to play a role. Finally, the sympathetic nervous system is thought to be involved in the pathogenesis of the hyperdynamic circulation associated with portal hypertension, although the nature and extent of its role is not completely understood. In this review, we discuss the different mechanisms known to contribute to this complex phenomenon.

Role of HSP-90 for increased nNOS-mediated vasodilation in mesenteric arteries in portal hypertension

AIM: To explore the role of heat shock protein-90 (HSP-90) for nitrergic vasorelaxation in the splanchnic circulation in rats with and without portal hypertension.

METHODS: Neuronal nitric oxide synthase (nNOS) and HSP-90 were analyzed by immunofluorescence, western blotting and co-immunoprecipitation in the mesenteric vasculature and isolated nerves of portal-vein-ligated (PVL) rats and sham operated rats. In vitro perfused de-endothelialized mesenteric arterial vasculature was preconstricted with norepinephrine (EC₈₀) and tested for nNOS-mediated vasorelaxation by periarterial nerve stimulation (PNS, 2-12 Hz, 45V) before and after incubation with geldanamycin (specific inhibitor of HSP-90 signalling, 3 μg/mL) or L-NAME (non-specific NOS-blocker, 10^-4 mol/L).

RESULTS: nNOS and HSP-90 expression was significantly increased in mesenteric nerves from PVL as compared to sham rats. Moreover, nNOS and HSP-90 were visualized in mesenteric nerves by immunofluorescence and immunoprecipitation of nNOS co-immunoprecitated HSP-90 in sham and PVL rats. PNS induced a frequency-dependent vasorelaxation which was more pronounced in PVL as compared to sham rats. L-NAME and geldanamycin markedly reduced nNOS-mediated vasorelaxation abrogating differences between the study groups. The effect of L-NAME and geldanamycin on nNOS-mediated vasorelaxation was significantly greater in PVL than in sham animals. However, no difference in magnitude of effect between L-NAME and geldanamycin was noted.

CONCLUSION: HSP-90 acts as a signalling mediator of nNOS-dependent nerve mediated vascular responses in mesenteric arteries, and the increased nitrergic vasorelaxation observed in portal hypertension is mediated largely by HSP-90.

Pulmonary dysfunction and hepatopulmonary syndrome in cirrhosis and portal hypertension

BACKGROUND

Pulmonary dysfunction including the hepatopulmonary syndrome (HPS) is an important complication to cirrhosis and portal hypertension. However, the precise relation to liver dysfunction and the prevalence of HPS are unclear.

AIMS

We therefore aimed to assess (i) the prevalence of HPS in consecutive alcoholic cirrhotic patients, (ii) the degree of pulmonary dysfunction in relation to liver function and (iii) the response of a 100% oxygen test on cardiopulmonary and peripheral oxygenation.

METHODS

Fifty patients with cirrhosis and 12 matched healthy controls were entered in this study. All underwent haemodynamic and pulmonary investigations [lung diffusing capacity for carbon monoxide (DLCO), contrast-enhanced echocardiography and detection of extrapulmonary shunt fraction]. A 100% oxygen test was performed with the assessment of arterial oxygen tension (PaO(2)), the alveolar-arterial oxygen gradient (AaPO(2)) and peripheral transcutaneous oxygen tension (tcPO(2)).

RESULTS

The prevalence of HPS was 10%. PaO(2) and DLCO were reduced in 32 and 72% and AaPO(2), was increased in 60% of the patients respectively. DLCO correlated with indicators of liver dysfunction (galactose elimination capacity, P<0.01, indocyanine green clearance, P<0.001), portal hypertension (post-sinusoidal resistance, P<0.01) and central hypovolaemia (central and arterial blood volume, P<0.01). After 100% oxygen inhalation, the changes in PaO(2), AaPO(2), tcPO(2) and heart rate were abnormal in the patients compared with controls (P<0.02).

CONCLUSIONS

Pulmonary dysfunction in alcoholic cirrhosis is common and relates to different aspects of liver dysfunction, whereas the prevalence of HPS is low. The haemodynamic response to oxygen inhalation is clearly impaired and HPS and pulmonary dysfunction seem to be caused by different pathophysiological mechanisms.