Increased cerebrovascular resistance in cirrhotic patients with ascites

Cervicocerebral atherosclerosis and its hepatic and coronary risk factors in patients with liver cirrhosis

Background/Aims

We aimed to investigate the silent atherosclerotic burden of cervicocephalic vessels in cirrhotic patients compared with the general population, as well as the relevant risk factors including coronary parameters.

Methods

This study included 993 stroke-free patients with liver cirrhosis (LC) who underwent magnetic resonance angiography (MRA) of the head and neck as a pre-liver transplant assessment and 6,099 health checkup participants who underwent MRA examination. The two cohorts were matched for cerebrovascular risk factors, and the prevalence of atherosclerosis in major intracranial and extracranial arteries was compared in 755 matched pairs. Moreover, traditional, hepatic, and coronary variables related to cerebral atherosclerosis were assessed in cirrhotic patients.

Results

Overall, intracranial atherosclerosis was significantly less prevalent in the LC group than in the matched control group (2.3% vs. 5.4%, P=0.002), whereas the prevalence of extracranial atherosclerosis was similar (4.4% vs. 5.8%, P=0.242). These results were maintained in multivariate analyses of the pooled samples, with corresponding adjusted odds ratios [ORs] of LC of 0.56 and 0.77 (95% confidence intervals [CIs], 0.36–0.88 and 0.55–1.09). In the LC group, lower platelet count was inversely correlated with intracranial atherosclerosis (adjusted OR, 0.31; 95% CI, 0.13–0.76). Coronary artery calcium (CAC) score ≥100 was the only predictive factor for both intracranial and extracranial atherosclerosis (adjusted ORs, 4.06 and 5.43, respectively).

Conclusions

LC confers protection against intracranial atherosclerosis, and thrombocytopenia may be involved in this protective effect. High CAC score could serve as a potential surrogate for cervicocerebral vascular screening in asymptomatic cirrhotic patients.

Hepatorenal syndrome in children: a review

Hepatorenal syndrome (HRS) occurs in patients with cirrhosis or fulminant hepatic failure and is a kind of pre-renal failure due to intense reduction of kidney perfusion induced by severe hepatic injury. While other causes of pre-renal acute kidney injury (AKI) respond to fluid infusion, HRS does not. HRS incidence is 5% in children with chronic liver conditions before liver transplantation. Type 1 HRS is an acute and rapidly progressive form that often develops after a precipitating factor, including gastrointestinal bleeding or spontaneous bacterial peritonitis, while type 2 is considered a slowly progressive form of kidney failure that often occurs spontaneously in chronic ascites settings. HRS pathogenesis is multifactorial. Cirrhosis causes portal hypertension; therefore, stasis and release of vasodilator substances occur in the hepatic vascular bed, leading to vasodilatation of splanchnic arteries and systemic hypotension. Many mechanisms seem to work together to cause this imbalance: splanchnic vasodilatation; vasoactive mediators; hyperdynamic circulation states and subsequent cardiac dysfunction; neuro-hormonal mechanisms; changes in sympathetic nervous system, renin-angiotensin system, and vasopressin. In patients with AKI and cirrhosis, fluid expansion therapy needs to be initiated as soon as possible and nephrotoxic drugs discontinued. Once HRS is diagnosed, pharmacological treatment with vasoconstrictors, mainly terlipressin plus albumin, should be initiated. If there is no response, other options can include surgical venous shunts and kidney replacement therapy. In this regard, extracorporeal liver support can be a bridge for liver transplantation, which remains as the ideal treatment. Further studies are necessary to investigate early biomarkers and alternative treatments for HRS.

Hepatic Encephalopathy-Associated Cerebral Vasculopathy in Acute-on-Chronic Liver Failure: Alterations on Endothelial Factor Release and Influence on Cerebrovascular Function

The acute-on-chronic liver failure (ACLF) is a syndrome characterized by liver decompensation, hepatic encephalopathy (HE) and high mortality. We aimed to determine the mechanisms implicated in the development of HE-associated cerebral vasculopathy in a microsurgical liver cholestasis (MHC) model of ACLF. Microsurgical liver cholestasis was induced by ligating and extracting the common bile duct and four bile ducts. Sham-operated and MHC rats were maintained for eight postoperative weeks Bradykinin-induced vasodilation was greater in middle cerebral arteries from MHC rats. Both Nω-Nitro-L-arginine methyl ester and indomethacin diminished bradykinin-induced vasodilation largely in arteries from MHC rats. Nitrite and prostaglandin (PG) F_1α releases were increased, whereas thromboxane (TX) B₂ was not modified in arteries from MHC. Expressions of endothelial nitric oxide synthase (eNOS), inducible NOS, and cyclooxygenase (COX) 2 were augmented, and neuronal NOS (nNOS), COX-1, PGI₂ synthase, and TXA₂S were unmodified. Phosphorylation was augmented for eNOS and unmodified for nNOS. Altogether, these endothelial alterations might collaborate to increase brain blood flow in HE.

Technetium-99m-labeled macroaggregated albumin lung perfusion scan for diagnosis of hepatopulmonary syndrome: A prospective study comparing brain uptake and whole-body uptake

BACKGROUND

Hepatopulmonary syndrome (HPS) is an arterial oxygenation defect induced by intrapulmonary vascular dilatation (IPVD) in the setting of liver disease and/or portal hypertension. This syndrome occurs most often in cirrhotic patients (4%–32%) and has been shown to be detrimental to functional status, quality of life, and survival. The diagnosis of HPS in the setting of liver disease and/or portal hypertension requires the demonstration of IPVD (i.e., diffuse or localized abnormally dilated pulmonary capillaries and pulmonary and pleural arteriovenous communications) and arterial oxygenation defects, preferably by contrast-enhanced echocardiography and measurement of the alveolar-arterial oxygen gradient, respectively.

AIM

To compare brain and whole-body uptake of technetium for diagnosing HPS.

METHODS

Sixty-nine patients with chronic liver disease and/or portal hypertension were prospectively included. Brain uptake and whole-body uptake were calculated using the geometric mean of technetium counts in the brain and lungs and in the entire body and lungs, respectively.

RESULTS

Thirty-two (46%) patients had IPVD as detected by contrast-enhanced echocardiography. The demographics and clinical characteristics of the patients with and without IPVD were not significantly different with the exception of the creatinine level (0.71 ± 0.18 mg/dL vs 0.83 ± 0.23 mg/dL; P = 0.041), alveolar-arterial oxygen gradient (23.2 ± 13.3 mmHg vs 16.4 ± 14.1 mmHg; P = 0.043), and arterial partial pressure of oxygen (81.0 ± 12.1 mmHg vs 90.1 ± 12.8 mmHg; P = 0.004). Whole-body uptake was significantly higher in patients with IPVD than in patients without IPVD (48.0% ± 6.1% vs 40.1% ± 8.1%; P = 0.001). The area under the curve of whole-body uptake for detecting IPVD was significantly higher than that of brain uptake (0.75 vs 0.54; P = 0.025). The optimal cut-off values of brain uptake and whole-body uptake for detecting IPVD were 5.7% and 42.5%, respectively, based on Youden’s index. The sensitivity, specificity, and accuracy of brain uptake > 5.7% and whole-body uptake > 42.5% for detecting IPVD were 23%, 89%, and 59% and 100%, 52%, and 74%, respectively.

CONCLUSION

Whole-body uptake is superior to brain uptake for diagnosing HPS.

Transcranial Doppler waveform changes due to increased cerebrovascular resistance and raised intracranial pressure in a patient with cirrhosis: A difference in shapes, not in numbers

We report and discuss a case that illustrate the clinical utility of transcranial Doppler (TCD) ultrasound in a patient with cirrhosis. A 43-year-old female presented with acute decompensation of cirrhosis with hepatic encephalopathy, requiring mechanical ventilation. TCD showed low diastolic flow velocities and high pulsatility index (PI) consistent with increased cerebrovascular resistance (CVR). The flow velocities and PI normalized over a period of few days and correlated well with neurological improvement after treatment. Subsequently, the patient developed a large intracerebral hemorrhage with mass effect. The TCD measurements in intracranial hypertension were similar to those with cirrhosis and hepatic encephalopathy. However, the windkessel notch in the systolic phase of TCD waveform, related to the distensibility of arterial wall, was absent during raised intracranial pressure (ICP). The absence of a windkessel notch may help to differentiate a high downstream resistance due to raised ICP from increased CVR.

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.

Minimal Hepatic Encephalopathy is Associated with Increased Cerebral Vascular Resistance. A Transcranial Doppler Ultrasound Study

Minimal hepatic encephalopathy (MHE) is a subclinical complication of liver cirrhosis with a relevant social impact. Thus, there is urgent need to implement easy to use diagnostic tools for the early identification of affected patients. The aim of this study was to investigate cerebral blood flow, systemic hemodynamics as well as endothelial function of cirrhotic patients with MHE, and to verify their change after treatment with rifaximin. Fifty cirrhotic patients with or without MHE and an equal number of healthy controls underwent transcranial Doppler ultrasound (TCD), abdominal Doppler ultrasound (US), and measurement of flow mediated dilation (FMD). In cirrhotic patients diagnosed with MHE receiving rifaximin, the tests were repeated at the end of treatment. Middle (MCA) and posterior (PCA) cerebral artery resistive (RI) and pulsatility (PI) indices were higher in cirrhotic patients than controls, as well as renal and splenic artery RI. Conversely, FMD was reduced. MCA-RI and PI were even higher in cirrhotic patients with MHE compared to those without; a MCA-RI cut-off of 0.65 showed an accuracy of 74% in discriminating the presence of MHE, with 65% sensitivity and 76% specificity. Rifaximin treatment showed no efficacy in the modulation of cerebral vascular flow. In conclusion, cirrhotic patients with MHE have significantly increased cerebral vascular resistances that are not improved by rifaximin treatment. MCA-RI measurement has a good accuracy for the diagnosis of MHE and can be useful for the early identification of this harmful complication of liver cirrhosis.

Changes in Cerebral Hemodynamics in Patients With Cirrhosis After Liver Transplantation

Improvement in cognitive function after orthotopic liver transplantation (LT) has been demonstrated in the acute setting immediately after LT and in acute liver failure. However, the longterm changes in cerebral hemodynamics after LT remain unexplored. Therefore, we aimed to evaluate the longterm changes in cerebral hemodynamics of patients with cirrhosis after LT. In this prospective cohort study, we performed transcranial Doppler ultrasonography (TCD) measuring the pulsatility index (PI), resistance index (RI), and breath-holding index (BHI) to evaluate cerebrovascular structural integrity and reactivity, respectively, in both middle cerebral arteries before and after LT. Neuropsychometric tests and West-Haven criteria were used for hepatic encephalopathy (HE) characterization. Interleukin 6 and tumor necrosis factor α plasma levels were measured. Descriptive statistics and Wilcoxon's test were used. There were 27 patients who were included. Median follow-up after LT was 6 months, mean age before LT was 46.3 ± 10.3 years, the main etiology was hepatitis C virus (59%), and most of the patients were Child-Pugh B (15/27). Model for End-Stage Liver Disease (MELD) score was 16 ± 7.5, MELD-Na was 19.3 ± 7.1, Psychometric Hepatic Encephalopathy Score was -3.48 ± 3.66, and critical flicker fusion (CFF) was 40.28 ± 5.70 Hz. Before LT, 17/27 patients had HE and 11/27 ascites. A decrease of 20.8% and 13.5% in PI and RI was observed after LT (P < 0.001, both), together with an increase in BHI (32.4%, P = 0.122). These changes in cerebral hemodynamics paralleled those in systemic inflammation. Clinical improvement in cognition was observed in all patients with overt HE after LT. In conclusion, these results show a significant improvement in cerebral hemodynamics after LT, obtained through TCD, indicating less arterial cerebral vasoconstriction together with a decrease in systemic inflammation. Changes in cerebral vasoconstriction can be the basis for the improvement in cognitive function after LT in the long term.

Sublingual microcirculatory alterations in cirrhotic patients

OBJECTIVE

To assess sublingual microcirculation in cirrhotic patients and its relationship to spider angiomas, complications, and outcome.

METHODS

Thirty-one cirrhotic patients were prospectively compared to 31 matched controls. Sublingual microcirculation was evaluated by videomicroscopy. We specifically looked for capillaries with increased RBCV, which was defined as a velocity higher than the percentile 100th of controls.

RESULTS

Compared to controls, cirrhotic patients showed decreased total and PVD (14.4 ± 2.2 vs 16.0 ± 1.3 and 14.1 ± 2.3 vs 15.9 ± 1.6 mm/mm² , respectively, P < .001 for both) and increased HFI (0.64 ± 0.39 vs 0.36 ± 0.21, P = .001). They also exhibited high RBCV in 2% of the microvessels (P < .0001). Patients with MELD score ≥10 had higher RBCV than patients with score <10 (1414 ± 290 vs 1206 ± 239 μm/s, P < .05). Patients with spider angiomas showed lower vascular densities. Microcirculation did not differ between survivors and nonsurvivors.

CONCLUSIONS

Cirrhosis is associated with microcirculatory alterations that can be easily monitored in the sublingual mucosa. Alterations included decreased density and PPV and hyperdynamic microvessels. The most striking finding, however, was the microvascular heterogeneity. Patients with spider angiomas had more severe alterations. Larger studies should clarify the relationship between microcirculatory abnormalities and outcome.

Living Donor Liver Transplantation in Acute Liver Failure Patients with Grade IV Encephalopathy: Is Deep Hepatic Coma Still an Absolute Contraindication? A Successful Single-Center Experience

Background

The prognosis of the patients of acute liver failure (ALF) with onset of hepatic coma is often dismal. ALF is a well-accepted indication for liver transplantation (LT) and has markedly improved the prognosis of these patients. However, its role in ALF patients with onset of hepatic coma has never been elucidated before. The aim of our study was to analyze the outcome in patients of ALF with hepatic coma who underwent LT.

Material/Methods

From January 2002 to December 2015, a total of 726 liver transplantations were done at China Medical University Hospital, Taiwan. The hospital database of 59 recipients that underwent LT for ALF was analyzed. Eleven ALF patients with the onset of hepatic coma (grade IV encephalopathy) requiring mechanical ventilatory support were retrospectively analyzed. The patients were sub-grouped in 2 groups depending on the timing of LT after the onset of hepatic coma: Group A had LT within 48 h of onset of coma (n=7) and Group B had LT after 48 h of onset of coma (n=4).

Results

The study cohort (group A and B) comprised 8 males and 3 females, with an average age of 39.63±13.95 years (range, 13 to 63). Ten patients received living donor liver transplantation (LDLT) and deceased donor liver transplantation (DDLT) was done in 1 recipient. All the patients in group A had complete neurological recovery and were extubated within 48 h after LT, whereas extubation was delayed for various reasons for group B patients. At a mean follow up of 36 months (range, 20 to 76 months), the overall survival of all the recipients (group A and B) was 72%. Three-year survival for Group A (n=7) was 85% and for Group B (n=4) it was 50%. There were no acute rejection episodes.

Conclusions

LT is an acceptable modality of treatment for patients of ALF with new onset of hepatic coma. Neurological recovery is expected in all patients if LT can be done within 48 h of onset of hepatic coma without increasing the risk of morbidity. Due to shortage of deceased donor organs in Asia, LDLT can be used proactively, with a success rate comparable to that of non-ALF patients undergoing LT.

Cirrhotic cardiomyopathy: is there any correlation between the stage of cardiac impairment and the severity of liver disease?

Cirrhotic cardiomyopathy is associated with poor prognosis and risk of acute heart failure after liver transplantation or interventional procedures. We aimed to assess the relationship between the severity of cardiac impairment and hepatic disease. Eighty patients and eighty controls underwent echocardiography, tissue Doppler imaging and speckle tracking measures. We assess the correlation between echocardiographic parameters and Child and MELD scores. Systolic parameters function (s wave, p < 0.001) and global longitudinal strain (p < 0.001) as well as diastolic parameters were significantly more impaired in cirrhotic patients compared to controls. There were no differences among the different groups in 'Child score' regarding systolic function as well as diastolic function. Paradoxically, the left atrium size correlated positively to both Child (p = 0.01, r = 0.26) and MELD scores (p = 0.02, r = 0.24). Left ventricular ejection fraction was significantly lower in decompensated patients as compared to compensated patients(p = 0.02).. We did not identify any association between severity of liver disease and cardiac dysfunction. Therefore, a transthoracic echocardiography should be performed in all cirrhotic patients before interventional and surgical procedures regardless of the severity of liver disease.

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.

Severity-specific alterations in CBF, OEF and CMRO2 in cirrhotic patients with hepatic encephalopathy

OBJECTIVES

To assess how the severity of hepatic encephalopathy (HE) affects perfusion and metabolic changes in cirrhotic patients and the association between severity and liver disease and anemia.

METHODS

The study groups comprised 31 healthy subjects and 33 cirrhotic patients who underwent MR examinations, and blood and neuropsychological tests. Of the cirrhotic patients, 14 were unaffected, and 11 had covert HE (CHE) and 8 overt HE (OHE). Global cerebral blood flow (CBF), oxygen extraction fraction (OEF), and metabolic rate of oxygen (CMRO2) were noninvasively measured by phase-contrast and T2-relaxation-under-spin-tagging MRI. Correlations were performed between MR measurements, hematocrits, ammonia levels, Child-Pugh scores and neuropsychological test scores.

RESULTS

Compared with the values in healthy subjects, CBF was higher in unaffected patients, the same in CHE patients and lower in OHE patients, OEF was higher in all patients, and CMRO2 was the same in unaffected and CHE patients and lower in OHE patients. Hematocrit was negatively correlated with CBF and OEF, but not with CMRO2. Ammonia level was negatively correlated with CBF and CMRO2, and Child-Pugh score was negatively correlated with CMRO2.

CONCLUSIONS

The severity-associated alterations in cirrhotic patients indicate that homeostasis of oxygen delivery and oxidative metabolism in HE is regulated by multiple mechanisms. These physiological alterations appeared to be associated with the degree of anemia, ammonia level, and liver function.

KEY POINTS

• CBF, OEF and CMRO2 did not change monotonically with HE progression. • Anemia possibly contributed to CBF and OEF changes in cirrhotic patients. • Liver dysfunction mainly contributed to changes in CMRO2 in cirrhotic patients.

Ammonia toxicity: from head to toe?

Ammonia is diffused and transported across all plasma membranes. This entails that hyperammonemia leads to an increase in ammonia in all organs and tissues. It is known that the toxic ramifications of ammonia primarily touch the brain and cause neurological impairment. However, the deleterious effects of ammonia are not specific to the brain, as the direct effect of increased ammonia (change in pH, membrane potential, metabolism) can occur in any type of cell. Therefore, in the setting of chronic liver disease where multi-organ dysfunction is common, the role of ammonia, only as neurotoxin, is challenged. This review provides insights and evidence that increased ammonia can disturb many organ and cell types and hence lead to dysfunction.

Ammonia mediates cortical hemichannel dysfunction in rodent models of chronic liver disease

The pathogenesis of hepatic encephalopathy (HE) in cirrhosis is multifactorial and ammonia is thought to play a key role. Astroglial dysfunction is known to be present in HE. Astrocytes are extensively connected by gap junctions formed of connexins, which also exist as functional hemichannels allowing exchange of molecules between the cytoplasm and the extracellular milieu. The astrocyte-neuron lactate shuttle hypothesis suggests that neuronal activity is fueled (at least in part) by lactate provided by neighboring astrocytes. We hypothesized that in HE, astroglial dysfunction could impair metabolic communication between astrocytes and neurons. In this study, we determined whether hyperammonemia leads to hemichannel dysfunction and impairs lactate transport in the cerebral cortex using rat models of HE (bile duct ligation [BDL] and induced hyperammonemia) and also evaluated the effect of ammonia-lowering treatment (ornithine phenylacetate [OP]). Plasma ammonia concentration in BDL rats was significantly reduced by OP treatment. Biosensor recordings demonstrated that HE is associated with a significant reduction in both tonic and hypoxia-induced lactate release in the cerebral cortex, which was normalized by OP treatment. Cortical dye loading experiments revealed hemichannel dysfunction in HE with improvement following OP treatment, while the expression of key connexins was unaffected.

CONCLUSION

The results of the present study demonstrate that HE is associated with central nervous system hemichannel dysfunction, with ammonia playing a key role. The data provide evidence of a potential neuronal energy deficit due to impaired hemichannel-mediated lactate transport between astrocytes and neurons as a possible mechanism underlying pathogenesis of HE. (Hepatology 2017;65:1306-1318).

Role of ammonia, inflammation, and cerebral oxygenation in brain dysfunction of acute-on-chronic liver failure patients

Hepatic encephalopathy (HE) is a common feature of acute-on-chronic liver failure (ACLF). Although ammonia, inflammation, and cerebral oxygenation are associated with HE in acute liver failure, their roles in ACLF are unknown. The aim of this prospective, longitudinal study was to determine the role of these pathophysiological variables in ACLF patients with and without HE. We studied 101 patients with ACLF admitted to the intensive care unit. Severity of ACLF and HE, arterial ammonia, jugular venous oxygen saturation (JVO2 ), white blood cell count (WCC), and C-reactive protein were measured at days 0, 1, 3, and 7. Patients were followed until death or hospital discharge. Mortality was high (51 patients, 50.5%), especially in patients with HE of whom 35 of 53 (66.0%) died regardless of ACLF severity. At baseline, increased WCC and abnormal JVO2 (high or low) were independent predictors of death. Further deterioration in inflammation, JVO2 , and ammonia were also predictive of mortality. JVO2 deviation and hyperammonemia were associated with the presence and severity of HE; improvement in these parameters was associated with a reduction in HE grade. No direct interaction was observed between these variables in regards to mortality or HE. In conclusion, this study describes potential mechanisms of HE in ACLF indicating that ammonia and abnormal cerebral oxygenation are important. The results suggest that ammonia, JVO2 , and WCC are important prognostic biomarkers and therapeutic targets. The relative roles of these pathophysiological factors in the pathogenesis of HE in ACLF or guiding therapy to improve survival requires future study. Liver Transplantation 22 732-742 2016 AASLD.

Vascular Doppler ultrasonographic indices in cirrhosis: a case-control study with emphasis on the common carotid arteries

PURPOSE

To compare vascular Doppler waveform indices, particularly in the common carotid arteries, between cirrhotic and healthy subjects.

MATERIALS AND METHODS

A total of 60 patients with Class-B cirrhosis and 60 healthy matched counterparts were enrolled in this prospective study. Vascular Doppler waveform parameters including resistance and/or pulsatility indices (RI and PI, respectively) were obtained from the common carotid, renal, celiac, superior mesenteric, femoral and brachial arteries.

RESULTS

Compared to patients, healthy subjects had significantly higher mean PI and RI obtained from the common carotid (1.53 ± 0.20 vs. 1.43 ± 0.14, p = 0.03; 0.75 ± 0.02 vs. 0.72 ± 0.02, p < 0.001, respectively) and celiac arteries (2.00 ± 0.36 vs. 1.81 ± 0.34, p = 0.03; 0.80 ± 0.03 vs. 0.78 ± 0.02, p < 0.001, respectively). Both the mean PI and RI derived from the renal arteries, in contrast, were significantly higher in patients compared to that in controls (1.05 ± 0.13 vs. 1.11 ± 0.07, p = 0.03; 0.59 ± 0.03 vs. 0.63 ± 0.03, p < 0.001, respectively). The mean vascular impedance values obtained from the remaining arteries were comparable between the two groups.

CONCLUSIONS

Blood flow increases in the common carotid and celiac arteries of Class-B cirrhotic patients with elevated renovascular impedance.

Cerebral haemodynamics in cirrhotic patients with hepatic encephalopathy

BACKGROUND & AIMS

Factors other than elevated levels of ammonia may be implicated in hepatic encephalopathy (HE) pathophysiology, including abnormal cerebral haemodynamics. Transcranial Doppler ultrasonography (TCD) evaluates cerebrovascular structural integrity and reactivity, through pulsatility index (PI) and breath-holding index (BHI) respectively. The aim of this study was to evaluate cerebral haemodynamics by TCD in patients with compensated and decompensated cirrhosis, and patients with and without HE.

METHODS

We studied 90 subjects by TCD measuring PI and BHI in the middle cerebral artery: 30 with cirrhosis and no HE, 30 with cirrhosis and low-grade HE and 30 healthy subjects. Critical flicker frequency, psychometric hepatic encephalopathy score and West-Haven criteria were performed to assess MHE and HE respectively.

RESULTS

Pulsatility index increased in decompensated cirrhotics (Child ≥ 7) when compared with compensated cirrhotics and healthy subjects [median (IQR) 1.07 (0.95-1.21) vs 0.90 (0.83-1.05) vs 0.87 (0.78-0.96); P < 0.001]. A reverse relationship was observed for BHI among the three groups [0.82 (0.45-1.11) vs 1.20 (0.82-1.52) vs 1.28 (1.06-1.68); P < 0.001]. Similar findings were observed in decompensation [model for end-stage liver disease (MELD) score ≥14]. Patients with HE showed higher PI and lower BHI [1.05 (1.00-1.16) and 0.89 (0.59-1.15)], when compared with patients without HE [0.96 (0.83-1.13) and 1.00 (0.60-1.53)] or controls [0.87 (0.78-0.96) and 1.28 (1.06-1.68)] (P < 0.001 for PI, and P = 0.007 for BHI). In multivariate regression models, only PI predicted HE, but it was outperformed by MELD-sodium and tumour necrosis factor-alpha.

CONCLUSIONS

These results indicate that cerebral haemodynamics are altered in patients with cirrhosis, in relation to severity of disease and HE. Findings on impaired PI and BHI suggest that structural vascular damage and loss of vascular autoregulation are implicated in the pathophysiology of HE.

Clinical implications of the hyperdynamic syndrome in cirrhosis

The hyperdynamic syndrome is a late consequence of portal hypertension in cirrhosis. The principal hemodynamic manifestations of the hyperdynamic syndrome are high cardiac output, and increased heart rate and total blood volume, accompanied by reduced total systemic vascular resistance. Pathophysiology involves a complex of humoral and neural mechanisms that can determine hemodynamic changes, and lead to hyperdynamic circulation. In this review we focus our attention on the manifestations of the hyperdynamic syndrome. Some of these are well described and directly related to portal hypertension (varices, ascites, hepatic encephalopathy, and hepatorenal syndrome), while others, such as hepatopulmonary syndrome, portopulmonary hypertension, and cirrhotic cardiomyopathy, are less known as clinical manifestations related to cirrhosis and, therefore, merit further investigation.

Human serum albumin, systemic inflammation, and cirrhosis

Human serum albumin (HSA) is one of the most frequent treatments in patients with decompensated cirrhosis. Prevention of paracentesis-induced circulatory dysfunction, prevention of type-1 HRS associated with bacterial infections, and treatment of type-1 hepatorenal syndrome are the main indications. In these indications treatment with HSA is associated with improvement in survival. Albumin is a stable and very flexible molecule with a heart shape, 585 residues, and three domains of similar size, each one containing two sub-domains. Many of the physiological functions of HSA rely on its ability to bind an extremely wide range of endogenous and exogenous ligands, to increase their solubility in plasma, to transport them to specific tissues and organs, or to dispose of them when they are toxic. The chemical structure of albumin can be altered by some specific processes (oxidation, glycation) leading to rapid clearance and catabolism. An outstanding feature of HSA is its capacity to bind lipopolysaccharide and other bacterial products (lipoteichoic acid and peptidoglycan), reactive oxygen species, nitric oxide and other nitrogen reactive species, and prostaglandins. Binding to NO and prostaglandins are reversible, so they can be transferred to other molecules at different sites from their synthesis. Through these functions, HSA modulates the inflammatory reaction. Decompensated cirrhosis is a disease associated systemic inflammation, which plays an important role in the pathogenesis of organ or system dysfunction/failure. Although, the beneficial effects of HAS have been traditionally attributed to plasma volume expansion, they could also relate to its effects modulating systemic and organ inflammation.

Review article: advances in the management of patients with cirrhosis and portal hypertension-related renal dysfunction

BACKGROUND

In cirrhosis, portal hypertension is associated with a spectrum of renal dysfunction that has significant implications for morbidity and mortality.

AIM

To discuss recent progress in the patho-physiological mechanisms and therapeutic options for portal hypertension-related renal dysfunction.

METHODS

A literature search using Pubmed was performed.

RESULTS

Portal hypertension-related renal dysfunction occurs in the setting of marked neuro-humoral and circulatory derangement. A systemic inflammatory response is a pathogenetic factor in advanced disease. Such physiological changes render the individual vulnerable to further deterioration of renal function. Patients are primed to develop acute kidney injury when exposed to additional 'hits', such as sepsis. Recent progress has been made regarding our understanding of the aetiopathogenesis. However, treatment options once hepatorenal syndrome develops are limited, and prognosis remains poor. Various strategies to prevent acute kidney injury are suggested.

CONCLUSION

Prevention of acute kidney injury in high risk patients with cirrhosis and portal hypertension-related renal dysfunction should be a clinical priority.

Splanchnic vasodilation and hyperdynamic circulatory syndrome in cirrhosis

Portal hypertension is a clinical syndrome which leads to several clinical complications, such as the formation and rupture of esophageal and/or gastric varices, ascites, hepatic encephalopathy and hepato-renal syndrome. In cirrhosis, the primary cause of the increase in portal pressure is the enhanced resistance to portal outflow. However, also an increase in splanchnic blood flow worsens and maintains portal hypertension. The vasodilatation of arterial splanchnic vessels and the opening of collateral circulation are the determinants of the increased splanchnic blood flow. Several vasoactive systems/substances, such as nitric oxide, cyclooxygenase-derivatives, carbon monoxide and endogenous cannabinoids are activated in portal hypertension and are responsible for the marked splanchnic vasodilatation. Moreover, an impaired reactivity to vasoconstrictor systems, such as the sympathetic nervous system, vasopressin, angiotensin II and endothelin-1, plays a role in this process. The opening of collateral circulation occurs through the reperfusion and dilatation of preexisting vessels, but also through the generation of new vessels. Splanchnic vasodilatation leads to the onset of the hyperdynamic circulatory syndrome, a syndrome which occurs in patients with portal hypertension and is characterized by increased cardiac output and heart rate, and decreased systemic vascular resistance with low arterial blood pressure. Understanding the pathophysiology of splanchnic vasodilatation and hyperdynamic circulatory syndrome is mandatory for the prevention and treatment of portal hypertension and its severe complications.

Acute kidney injury in patients with cirrhosis: perils and promise

A 62-year-old man with cirrhosis secondary to hepatitis C and chronic alcohol abuse was admitted to the intensive care unit with hematemesis and mental status changes. Physical examination showed ascites and stigmata of chronic liver disease. Blood pressure was noted as 87/42 mm Hg and laboratory studies showed a serum creatinine level of 0.8 mg/dL, an estimated glomerular filtration rate of 84 mL/min/1.73 m(2) calculated using the Modification of Diet in Renal Disease Study equation, a serum sodium level of 123 mEq/L, a total serum bilirubin level of 4.3 mg/dL, and an international normalization ratio of 1.6. The patient was resuscitated with packed red blood cells and fresh-frozen plasma and bleeding was controlled. However, on the third day of admission, creatinine level increased to 1.5 mg/dL. Examination of urine sediment showed 1 to 5 bilirubin-stained granular casts per high-powered field and a few renal tubular epithelial cells. The urine sodium level was 21 mEq/L and the fractional excretion of sodium was 0.43%.

LEFT ventricular function assessed by echocardiography in cirrhosis: relationship to systemic hemodynamics and renal dysfunction

BACKGROUND & AIMS

The current study aimed at assessing the potential role of cardiac abnormalities in the pathogenesis of circulatory and renal dysfunction in cirrhosis.

METHODS

One hundred and fifty-two patients (34 without ascites, 95 with ascites without renal failure and 21 with hepatorenal syndrome) were evaluated using Doppler echocardiography. In 102 patients, diastolic function was assessed by measuring parameters related to ventricular filling velocity, mitral annulus velocity and left atrial dimensions. Cardiopulmonary pressures were also measured by cardiac catheterization in 54 patients. In 50 additional patients, left ventricular myocardial strain was performed to estimate myocardial contractility and systolic function.

RESULTS

Grade 1 and 2 diastolic dysfunction was present in 41% and 16% of the patients, respectively. There was no patient with severe grade 3 diastolic dysfunction. Grade 2 diastolic dysfunction was associated with higher cardiopulmonary pressures but values were within the normal limits in all cases. Diastolic dysfunction directly correlated with liver failure but not with the degree of impairment in circulatory and renal function. The proportion of patients without or with grade 1 or 2 diastolic dysfunction was similar in patients with compensated cirrhosis, with ascites without renal failure or with hepatorenal syndrome despite marked differences in the degree of circulatory dysfunction, as indicated by plasma renin activity and noradrenaline concentration. The heart rate and systolic function were normal in all cases. There were no differences between patients without ascites, with ascites without renal failure or with HRS, despite marked differences in the activity of the renin-angiotensin system and sympathetic nervous system. These features indicate an impaired response of cardiac chronotropic and inotropic function to changes in systemic hemodynamics.

CONCLUSIONS

These data indicates that: (1) diastolic dysfunction is frequent in cirrhosis but in most cases it is of mild degree and does not increase the cardiopulmonary pressure to abnormal levels. This feature, which may be due to the central hypovolemia of cirrhosis, probably accounts for the lack of symptoms associated with this condition. (2) Diastolic dysfunction in cirrhosis is unrelated to circulatory dysfunction, ascites and HRS. (3) In cirrhosis, there is a lack of response of the left ventricular systolic and chronotropic function to peripheral arterial vasodilation and activation of the sympathetic nervous system and this feature is an important contributory factor to the progression of circulatory dysfunction and the pathogenesis of ascites and HRS.

Asymmetric dimethylarginine is strongly associated with cognitive dysfunction and brain MR spectroscopic abnormalities in cirrhosis

BACKGROUND & AIMS

Asymmetric dimethylarginine (ADMA) is an inhibitor of nitric oxide synthase that accumulates in liver disease and may contribute to hepatic encephalopathy (HE). We aimed at evaluating the association of ADMA with cognition and brain MR spectroscopy (MRS) in cirrhosis.

METHODS

Cirrhotic patients with/without prior HE and non-cirrhotic controls underwent cognitive testing and ADMA determination. A subgroup underwent brain MRS [glutamine/glutamate (Glx), myoinositol (mI), N-acetyl-aspartate (NAA) in parietal white, occipital gray, and anterior cingulated (ACC)]. Cognition and ADMA in a cirrhotic subgroup before and one month after transjugular intrahepatic portosystemic shunting (TIPS) were also tested. Cognition and MRS values were correlated with ADMA and compared between groups using multivariable regression. ADMA levels were compared between those who did/did not develop post-TIPS HE.

RESULTS

Ninety cirrhotics (MELD 13, 54 prior HE) and 16 controls were included. Controls had better cognition and lower ADMA, Glx, and higher mI compared to cirrhotics. Prior HE patients had worse cognition, higher ADMA and Glx and lower mI compared to non-HE cirrhotics. ADMA was positively correlated with MELD (r=0.58, p<0.0001), abnormal cognitive test number (r=0.66, p<0.0001), and Glx and NAAA (white matter, ACC) and negatively with mI. On regression, ADMA predicted number of abnormal tests and mean Z-score independent of prior HE and MELD. Twelve patients underwent TIPS; 7 developed HE post-TIPS. ADMA increased post-TIPS in patients who developed HE (p=0.019) but not in others (p=0.89).

CONCLUSIONS

A strong association of ADMA with cognition and prior HE was found independent of the MELD score in cirrhosis.

Hepatorenal syndrome: a severe, but treatable, cause of kidney failure in cirrhosis

Hepatorenal syndrome (HRS) is a unique type of kidney failure that occurs in advanced cirrhosis. It is characterized by functional impairment of the kidneys due to vasoconstriction of the renal arteries in the setting of preserved tubular function and absence of significant histologic abnormalities. Renal vasoconstriction in HRS is due to severe vasodilation of the splanchnic arteries associated with portal hypertension, leading to a decrease in effective arterial blood volume and arterial pressure. HRS commonly develops after a trigger, usually a bacterial infection, that disrupts the arterial circulation, but it also may occur spontaneously. There are 2 forms of HRS: type 1 is characterized by an acute progressive decrease in kidney function and very short survival without treatment, whereas type 2 features stable less severe kidney failure and longer survival compared with type 1. A liver transplant is the preferred treatment for HRS. Pharmacologic treatment with vasoconstrictors to reverse splanchnic vasodilation, together with albumin, is effective in 40%-50% of patients with type 1 HRS and improves survival. The drug of choice is the vasopressin analogue terlipressin. Renal replacement therapy should not be used as first-line therapy.

Ammonia reduction with ornithine phenylacetate restores brain eNOS activity via the DDAH-ADMA pathway in bile duct-ligated cirrhotic rats

Ammonia is central in the pathogenesis of hepatic encephalopathy, which is associated with dysfunction of the nitric oxide (NO) signaling pathway. Ornithine phenylacetate (OP) reduces hyperammonemia and brain water in cirrhotic animals. This study aimed to determine whether endothelial NO synthase activity is altered in the brain of cirrhotic animals, whether this is associated with changes in the endogenous inhibitor, asymmetric-dimethylarginine (ADMA) and its regulating enzyme, dimethylarginine-dimethylaminohydrolase (DDAH-1), and whether these abnormalities are restored by ammonia reduction using OP. Sprague-Dawley rats were studied 4-wk after bile duct ligation (BDL) (n = 16) or sham operation (n = 8) and treated with placebo or OP (0.6 g/kg). Arterial ammonia, brain water, TNF-α, plasma, and brain ADMA were measured using standard techniques. NOS activity was measured radiometrically, and protein expression for NOS enzymes, ADMA, DDAH-1, 4-hydroxynonenol ((4)HNE), and NADPH oxidase (NOX)-1 were measured by Western blotting. BDL significantly increased arterial ammonia (P < 0.0001), brain water (P < 0.05), and brain TNF-α (P < 0.01). These were reduced significantly by OP treatment. The estimated eNOS component of constitutive NOS activity was significantly lower (P < 0.05) in BDL rat, and this was significantly attenuated in OP-treated animals. Brain ADMA levels were significantly higher and brain DDAH-1 significantly lower in BDL compared with sham (P < 0.01) and restored toward normal following treatment with OP. Brain (4)HNE and NOX-1 protein expression were significantly increased in BDL rat brain, which were significantly decreased following OP administration. We show a marked abnormality of NO regulation in cirrhotic rat brains, which can be restored by reduction in ammonia concentration using OP.

Pathophysiology of portal hypertension and its clinical links

Portal hypertension is a major cause of morbidity and mortality in patients with liver cirrhosis. Intrahepatic vascular resistance due to architectural distortion and intrahepatic vasoconstriction, increased portal blood flow due to splanchnic vasodilatation, and development of collateral circulation have been considered as major factors for the development of portal hypertension. Recently, sinusoidal remodeling and angiogenesis have been focused as potential etiologic factors and various researchers have tried to improve portal hypertension by modulating these new targets. This article reviews potential new treatments in the context of portal hypertension pathophysiology concepts.

Hepatorenal syndrome in the intensive care unit

Hepatorenal syndrome (HRS) is a functional form of acute kidney injury (AKI) associated with advanced liver cirrhosis or fulminant hepatic failure. Various new concepts have emerged since the initial diagnostic criteria and definition of HRS was initially published. These include better understanding of the pathophysiological mechanisms involved in HRS, identification of bacterial infection (especially spontaneous bacterial peritonitis) as the most important HRS-precipitating event, recognition that insufficient cardiac output plays a role in the occurrence of HRS, and evidence that renal failure reverses with pharmacotherapy. Patients with HRS are often critically ill and, by definition, have multiorgan failure. The purpose of this review is to provide an update on novel advances in HRS, with emphasis on the different aspects of management of these patients in the intensive care unit.

Critical care of the end-stage liver disease patient awaiting liver transplantation

Patients with end-stage liver disease awaiting liver transplantation frequently require intensive care admission and management due to either complications of liver failure or to intercurrent illness, particularly infection. Mortality in such patients is high and the development of an illness necessitating intensive care unit management can influence transplant candidacy. Specialized support frequently requires hemodynamic support, mechanical ventilation, and renal support. In this review, areas of management of particular importance to patients with end-stage liver disease in the intensive care unit are discussed. These areas are hepatic encephalopathy, infectious diseases, cardiovascular support, mechanical ventilation, renal support and combined transplantation, and decisions regarding delisting. Current knowledge specific to these patients, when available, is discussed, current practice is described, and areas of uncertainty in the evidence are discussed.

Acute endotoxemia following transjugular intrahepatic stent-shunt insertion is associated with systemic and cerebral vasodilatation with increased whole body nitric oxide production in critically ill cirrhotic patients

BACKGROUND & AIMS

Transjugular intrahepatic stent-shunt (TIPSS) insertion, in patients with uncontrolled gastro-intestinal bleeding, often results in worsening of the systemic hemodynamics which can be associated with intracranial hypertension but the underlying mechanisms are unclear. This study explored the hypothesis that TIPSS insertion results in acute endotoxemia which is associated with increased nitric oxide production resulting in systemic and cerebral vasodilatation.

METHODS

Twelve patients with cirrhosis who were undergoing TIPSS for uncontrolled variceal bleeding were studied prior to and 1-h after TIPSS insertion. Changes in cardiac output (CO) and cerebral blood flow (CBF) were measured. NO production was measured using stable isotopes using l-[guanidino-(15)N(2)] arginine and l-[ureido-(13)C;5,5-(2)H(2)] citrulline infusion. The effect of pre- and post-TIPSS plasma on nitric oxide synthase (NOS) activity on human endothelial cell-line (HUVEC) was measured.

RESULTS

TIPSS insertion resulted in a significant increase in CO and CBF. Endotoxin and induced neutrophil oxidative burst increased significantly without any significant changes in cytokines. Whole body NO production increased significantly and this was associated with increased iNOS activity in the HUVEC lines. The change in NO production correlated with the changes in CO and CBF. Brain flux of ammonia increased without significant changes in arterial ammonia.

CONCLUSIONS

In conclusion, the insertion of TIPSS results in acute endotoxemia which is associated with increased nitric oxide production possibly through an iNOS dependent mechanism which may have important pathophysiological and therapeutic relevance to understanding the basis of circulatory failure in the critically ill cirrhotic patient.

[Adrenal insufficiency in cirrhosis]

Cortisol is a pluripotent hormone that is vital in the host adaptation to stress. It is essential to maintain the normal vascular tone, endothelial integrity and vascular permeability. Consequently, the failure of an appropriate adrenal response in the setting of critical illness, alteration known as relative adrenal insufficiency, may have important clinical consequences. The diagnosis of this entity is not possible on clinical grounds and relies on the measurement of plasma cortisol levels prior and after adrenal stimulation with synthetic corticotrophin. Several studies performed in the general population have shown that relative adrenal insufficiency contributes to vascular hyporesponsiveness in septic shock and increases mortality. However, contradictory data exist regarding the effects of hydrocortisone administration in these patients. Moreover, recent studies indicate that relative adrenal insufficiency is very frequent in patients with advanced cirrhosis and septic shock and in fulminant hepatic failure. This chapter summarizes the main aspects of the physiopathology, diagnosis and treatment of this entity in patients with acute or chronic liver disease.

Liver-kidney pathophysiological interrelationships in liver diseases

On the basis of several clinical and experimental researches, it is possible today to deepen the different mechanisms regarding kidney and liver relationships. However, the most studied field remains the renal function during liver disease. These alterations can be divided into: 1. Renal functional impairment is mainly considered due to hemodynamic derangement with a progressive decrease in peripheral vascular resistance (PVR) and an increase in cardiac output and rate, characteristic of hyperdynamic circulation, and outer cortex renal ischemia. Two principal forms of RFI characterize the hepatorenal syndrome (HRS) while in the first stage is based on the simple decrease in renal clearances with avid sodium retention. 2. Metabolic renal damage is principally due to abnormal serum levels of bile acids, bilirubin and perhaps toxic hepatic molecules which induce tubular dysfunction leading to RTA, of which type I, in the incomplete form, is the most common, varying between 30% and 50% of cases. It is mainly studied during cholestatic disease. 3. Organic renal impairment is principally based on immunological response to viral antigens and abnormal hepatic products which lead to the presence of immunocomplexes and cryoglobulins on the blood which tend to be deposited in the subendothelial and subepithelial glomerular areas, inducing complement activation, mesangial cell proliferation and monocyte-macrophage cell infiltration.

Hemodynamic changes in splanchnic blood vessels in portal hypertension

Portal hypertension (PHT) is associated with a hyperdynamic state characterized by a high cardiac output, increased total blood volume, and a decreased splanchnic vascular resistance. This splanchnic vasodilation is a result of an important increase in local and systemic vasodilators (nitric oxide, carbon monoxide, prostacyclin, endocannabinoids, and so on), the presence of a splanchnic vascular hyporesponsiveness toward vasoconstrictors, and the development of mesenteric angiogenesis. All these mechanisms will be discussed in this review. To decompress the portal circulation in PHT, portosystemic collaterals will develop. The presence of these portosystemic shunts are responsible for major complications of PHT, namely bleeding from gastrointestinal varices, encephalopathy, and sepsis. Until recently, it was accepted that the formation of collaterals was due to opening of preexisting vascular channels, however, recent data suggest also the role of vascular remodeling and angiogenesis. These points are also discussed in detail.

Pathogenesis and management of hepatorenal syndrome in patients with cirrhosis

Hepatorenal syndrome is a severe complication of advanced liver cirrhosis, in patients with ascites and marked circulatory dysfunction. It is clearly established that it has a functional nature, and that it is related to intense renal vasoconstriction. Despite its functional origin, the prognosis is very poor. In the present review, the most recent advances in diagnosis, pathophysiology, and treatment are discussed. Recent developments in pathophysiology are the basis of the new therapeutic strategies, which are currently under evaluation in randomised clinical trials.

Minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE), formerly known as subclinical hepatic encephalopathy, is the mild cognitive impairment commonly seen in patients who have cirrhosis. Current understanding suggests that MHE forms part of the spectrum of hepatic encephalopathy, although this remains to be proven. Although traditionally viewed as having negligible clinical significance, MHE has a significant impact on quality of life. MHE often goes undiagnosed because in many patients there is no evidence of clinically overt signs of impaired cognition. In addition, the diagnostic criteria for MHE have not been standardized, which means that the exact characteristics of MHE remain in question. This Review focuses on the pathogenesis and neuropsychological findings (incorporating neuroimaging) of MHE, as well as the effect of MHE on quality of life and survival, and developments in treatment.

[Hepatorenal syndrome]

Hepatorenal syndrome (HRS) is a severe complication in patients with cirrhosis and ascites. Renal insufficiency is functional and is caused by renal vasoconstriction. HRS occurs in 10% of patients with advanced cirrhosis. Diagnosis of HRS is based on ruling out other causes of renal insufficiency. There are two types of HRS: type 1 has rapid onset and progressive course and a mean survival of 15 days without treatment, while type 2 is less severe and progressive, with a mean survival of 6 months. Definitive treatment of HRS is liver transplantation. However, in the last few years administration of vasoconstrictive drugs or placement of portosystemic shunts have been shown to be effective in reversing HRS. Therefore, these measures may be used as a bridge before liver transplantation is performed. Finally, the risk of developing HRS in the context of spontaneous bacterial peritonitis can be prevented by administering albumin together with the corresponding antibiotics. In cases of severe acute alcoholic hepatitis, pentoxifylline can be administered.

Splanchnic and systemic vasodilatation: the patient

Arterial vasodilatation is one of the most important characteristics of cirrrhosis and portal hyptertension. Nowadays, it has been known that progressive vasodilatation is an essential factor contributing to hyperdynamic circulation and multiple organ dysfunction in liver cirrhosis. Over the past decades, numerous investigations have originated from the clinical observations. Clinicians and investigators have learned and applied new concepts of the pathophysiology of portal hypertension. For example, we now have effective pharmacologic treatment for hepatorenal syndrome. This review summarizes the developement of progressive vasodilatation syndrome in liver cirrhosis and portal hypertension with focus on the patients.