Physiopathology of splanchnic vasodilation in portal hypertension

Predictive model of in-hospital mortality in liver cirrhosis patients with hyponatremia: an artificial neural network approach

Hyponatremia can worsen the outcomes of patients with liver cirrhosis. However, it remains unclear about how to predict the risk of death in cirrhotic patients with hyponatremia. Patients with liver cirrhosis and hyponatremia were screened. Eligible patients were randomly divided into the training (n = 472) and validation (n = 471) cohorts. In the training cohort, the independent predictors for in-hospital death were identified by logistic regression analyses. Odds ratios (ORs) were calculated. An artificial neural network (ANN) model was established in the training cohort. Areas under curve (AUCs) of ANN model, Child-Pugh, model for end-stage liver disease (MELD), and MELD-Na scores were calculated by receiver operating characteristic curve analyses. In multivariate logistic regression analyses, ascites (OR = 2.705, P = 0.042), total bilirubin (OR = 1.004, P = 0.003), serum creatinine (OR = 1.004, P = 0.017), and international normalized ratio (OR = 1.457, P = 0.005) were independently associated with in-hospital death. Based on the four variables, an ANN model was established. Its AUC was 0.865 and 0.810 in the training and validation cohorts, respectively, which was significantly larger than those of Child-Pugh (AUC = 0.757), MELD (AUC = 0.765), and MELD-Na (AUC = 0.769) scores. An ANN model has been developed and validated for the prediction of in-hospital death in patients with liver cirrhosis and hyponatremia.

The Molecular Mechanisms of Portal Vein Thrombosis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) represents the sixth most diagnosed cancer worldwide and is the second leading cause of cancer-related death in the world. The association of HCC and portal vein thrombosis (PVT) represents an advanced stage of the tumor. PVT has a prevalence of about 25-50% in HCC, determining poor prognosis and a remarkable reduction in therapeutic perspectives in these patients, leading to severe complications such as ascites, metastasis, an increase in portal hypertension and potentially fatal gastrointestinal bleeding. The aim of this review is to evaluate the molecular mechanisms that are at the basis of PVT development, trying to evaluate possible strategies in the early detection of patients at high risk of PVT.

The Renin-Angiotensin System in Liver Disease

The renin-angiotensin system (RAS) is a complex homeostatic entity with multiorgan systemic and local effects. Traditionally, RAS works in conjunction with the kidney to control effective arterial circulation, systemic vascular resistance, and electrolyte balance. However, chronic hepatic injury and resulting splanchnic dilation may disrupt this delicate balance. The role of RAS in liver disease, however, is even more extensive, modulating hepatic fibrosis and portal hypertension. Recognition of an alternative RAS pathway in the past few decades has changed our understanding of RAS in liver disease, and the concept of opposing vs. "rebalanced" forces is an ongoing focus of research. Whether RAS inhibition is beneficial in patients with chronic liver disease appears to be context-dependent, but further study is needed to optimize clinical management and reduce organ-specific morbidity and mortality. This review presents the current understanding of RAS in liver disease, acknowledges areas of uncertainty, and describes potential areas of future investigation.

Recent developments in the management of ascites in cirrhosis

In recent years, advances have been made for treating ascites in patients with cirrhosis. Recent studies have indicated that several treatments that have been used for a long time in the management of portal hypertension may have beneficial effects that were not previously identified. Long-term albumin infusion may improve survival in patients with cirrhosis and ascites while beta-blockers may reduce ascites occurrence. Transjugular intrahepatic porto-systemic shunt (TIPS) placement may also improve survival in selected patients in addition to the control with ascites. Low-flow ascites pump insertion can be another option for some patients with intractable ascites. In this review, we summarize the latest data related to the management of ascites occurring in cirrhosis. There are still unanswered questions, such as the optimal use of albumin as a long-term therapy, the place of beta-blockers, and the best timing for TIPS placement to improve the natural history of ascites, as well as the optimal stent diameter to reduce the risk of shunt-related side-effects. These issued should be addressed in future studies.

Roles of β-adrenoceptor Subtypes and Therapeutics in Human Cardiovascular Disease: Heart Failure, Tachyarrhythmias and Other Cardiovascular Disorders

β-Adrenoceptors (β-ARs) provide an important therapeutic target for the treatment of cardiovascular disease. Three β-ARs, β1-AR, β2-AR, β3-AR are localized to the human heart. Activation of β1-AR and β2-ARs increases heart rate, force of contraction (inotropy) and consequently cardiac output to meet physiological demand. However, in disease, chronic over-activation of β1-AR is responsible for the progression of disease (e.g. heart failure) mediated by pathological hypertrophy, adverse remodelling and premature cell death. Furthermore, activation of β1-AR is critical in the pathogenesis of cardiac arrhythmias while activation of β2-AR directly influences blood pressure haemostasis. There is an increasing awareness of the contribution of β2-AR in cardiovascular disease, particularly arrhythmia generation. All β-blockers used therapeutically to treat cardiovascular disease block β1-AR with variable blockade of β2-AR depending on relative affinity for β1-AR vs β2-AR. Since the introduction of β-blockers into clinical practice in 1965, β-blockers with different properties have been trialled, used and evaluated, leading to better understanding of their therapeutic effects and tolerability in various cardiovascular conditions. β-Blockers with the property of intrinsic sympathomimetic activity (ISA), i.e. β-blockers that also activate the receptor, were used in the past for post-treatment of myocardial infarction and had limited use in heart failure. The β-blocker carvedilol continues to intrigue due to numerous properties that differentiate it from other β-blockers and is used successfully in the treatment of heart failure. The discovery of β3-AR in human heart created interest in the role of β3-AR in heart failure but has not resulted in therapeutics at this stage.

Portal Hypertension in Malnutrition and Sarcopenia in Decompensated Cirrhosis-Pathogenesis, Implications and Therapeutic Opportunities

Malnutrition and sarcopenia are highly prevalent in patients with decompensated cirrhosis and are associated with poorer clinical outcomes. Their pathophysiology is complex and multifactorial, with protein-calorie malnutrition, systemic inflammation, reduced glycogen stores and hormonal imbalances all well reported. The direct contribution of portal hypertension to these driving factors is however not widely documented in the literature. This review details the specific mechanisms by which portal hypertension directly contributes to the development of malnutrition and sarcopenia in cirrhosis. We summarise the existing literature describing treatment strategies that specifically aim to reduce portal pressures and their impact on nutritional and muscle outcomes, which is particularly relevant to those with end-stage disease awaiting liver transplantation.

Preventing Small-for-size Syndrome in Living Donor Liver Transplantation: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) is a well-recognized complication following liver transplantation (LT), with up to 20% developing this following living donor LT (LDLT). Preventing SFSS involves consideration of factors before the surgical procedure, including donor and recipient selection, and factors during the surgical procedure, including adequate outflow reconstruction, graft portal inflow modulation, and management of portosystemic shunts. International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplant Society of India Consensus Conference was convened in January 2023 to develop recommendations for the prediction and management of SFSS in LDLT. The format of the conference was based on the Grading of Recommendations, Assessment, Development, and Evaluation system. International experts in this field were allocated to 4 working groups (diagnosis, prevention, anesthesia, and critical care considerations, and management of established SFSS). The working groups prepared evidence-based recommendations to answer-specific questions considering the currently available literature. The working group members, independent panel, and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and evidence-based recommendations provided by working group 2 that can be implemented to prevent SFSS in LDLT patients.

Evidence-based hyponatremia management in liver disease

Hyponatremia is primarily a water balance disorder associated with high morbidity and mortality. The pathophysiological mechanisms behind hyponatremia are multifactorial, and diagnosing and treating this disorder remains challenging. In this review, the classification, pathogenesis, and step-by-step management approaches for hyponatremia in patients with liver disease are described based on recent evidence. We summarize the five sequential steps of the traditional diagnostic approach: 1) confirm true hypotonic hyponatremia, 2) assess the severity of hyponatremia symptoms, 3) measure urine osmolality, 4) classify hyponatremia based on the urine sodium concentration and extracellular fluid status, and 5) rule out any coexisting endocrine disorder and renal failure. Distinct treatment strategies for hyponatremia in liver disease should be applied according to the symptoms, duration, and etiology of disease. Symptomatic hyponatremia requires immediate correction with 3% saline. Asymptomatic chronic hyponatremia in liver disease is prevalent and treatment plans should be individualized based on diagnosis. Treatment options for correcting hyponatremia in advanced liver disease may include water restriction; hypokalemia correction; and administration of vasopressin antagonists, albumin, and 3% saline. Safety concerns for patients with liver disease include a higher risk of osmotic demyelination syndrome.

Oxidative stress triggers hyperdynamic circulation via central neural activation in portal hypertensive rats

BACKGROUND

Hyperdynamic circulation in portal hypertension (PHT) depends on central neural activation. However, the initiating mechanism that signals PHT to the central neural cardiovascular-regulatory centers remains unclear. We aimed to test the hypothesis that oxidative stress in the gut initiates the signal that activates central cardiovascular nuclei in portal hypertensive rats.

METHODS

Two groups of rats were used. One had portal hypertension produced by partial portal vein ligation, while controls underwent sham operation. Hemodynamics including portal pressure, cardiac output, mean arterial pressure (MAP) and peripheral vascular resistance were measured. Activation of central cardiovascular nuclei was determined by immunohistochemical Fos expression in the paraventricular nucleus (PVN) of the hypothalamus. Myeloperoxidase activity, an oxidative stress marker, was measured in the jejunum. Hydrogen peroxide, the antioxidant N-acetyl-cysteine (NAC) or saline controls were administered for 12-14 days by gavage or osmotic minipumps placed in the peritoneal cavity.

RESULTS

Compared with controls, PHT rats showed increased cardiac output (54.2 ± 9.5 vs 33.6 ± 2.4 ml/min/100 g BW, p < 0.01), decreased MAP (96.2 ± 6.4 mmHg vs 103.2 ± 7.8, p < 0.01) and systemic vascular resistance (1.84 ± 0.28 vs 3.14 ± 0.19 mmHg/min/ml/100 g BW, p < 0.01). PHT rats had increased jejunal myeloperoxidase and PVN Fos expression. NAC treatment eliminated the hyperdynamic circulation, decreased jejunal myeloperoxidase and PVN Fos expression in PHT rats, but had no effect on sham controls. H₂O₂ significantly increased PVN Fos expression and decreased MAP.

CONCLUSION

These results indicate that in PHT, mesenteric oxidative stress is the initial signal that activates chemoreceptors and triggers hyperdynamic circulation by central neural cardiovascular-regulatory centers.

Current and investigational drugs in early clinical development for portal hypertension

Introduction

The development of portal hypertension leads to a majority of complications associated with chronic liver disease. Therefore, adequate treatment of portal hypertension is crucial in the management of such patients. Current treatment options are limited and consist mainly of medications that decrease the hyperdynamic circulation, such as non-selective beta blockers, and treatment of hypervolemia with diuretics. Despite these options, mortality rates have not improved over the last two decades. Newer, more effective treatment options are necessary to help improve survival and quality of life in these patients.

Areas covered

Multiple preclinical models and clinical studies have demonstrated potential efficacy of a variety of new treatment modalities. We introduce treatment options including the use of vasodilation promotors, vasoconstriction inhibitors, anticoagulants, antiangiogenics, and anti-inflammatory drugs. We examine the most recent studies for treatment options within these drug classes and offer insights as to which show the most promise in this field.

Methodology

Published studies that identified novel medical treatment options of portal hypertension were searched using PubMed (https://pubmed.ncbi.nlm.nih.gov/). Clinical trials listed in Clinicaltrials.gov were also searched with a focus on more recent and ongoing studies, including those with completed recruitment. Searching with key terms including "portal hypertension" as well as individually searching specific treatment medications that were listed in other publications was carried out. Finally, current societal guidelines and recent review articles relevant to the management of portal hypertension were evaluated, and listed references of interest were included.

Conclusion

Many ongoing early phase studies demonstrate promising results and may shape the field of portal hypertension management in future. As concrete results become available, larger RCTs will be required before making definitive conclusions regarding safety and efficacy and whether or not they can be incorporated into routine clinical practice. Statins, anticoagulants, and PDE inhibitors have been among the most studied and appear to be most promising.

Hepatic perfusion as a new predictor of prognosis and mortality in critical care patients with acute-on-chronic liver failure

Background and aims

Liver diseases are frequent causes of morbidity and mortality worldwide. Liver diseases can lead to cirrhosis, with the risk of acute-on-chronic liver failure (ACLF). For the detection of changes in hepatic hemodynamics, Doppler ultrasonography is a well-established method. We investigated hepatic hemodynamics via serial Doppler ultrasonography to determine the predictive value of changes in hepatic perfusion for the outcome in patients with severe liver diseases compared to established prognostic models such as the MELD (Model for End-Stage Liver Disease) or CLIF-C (Chronic Liver Failure-Consortium) ACLF score.

Methods

In this prospective cohort study, hepatic perfusion was quantified at baseline before the initiation of treatment and every third day by means of serial measurements of the hepatic artery resistance index (HARI) and the maximum portal vein velocity (PVv) using Doppler ultrasonography in 50 consecutive patients with severe liver diseases admitted to a medical intensive care unit (MICU). The recorded hemodynamic parameters were compared to the MELD score, and the CLIF-C ACLF score to analyze their utility for the prediction of the outcome of patients with severe liver diseases, liver cirrhosis, and ACLF.

Results

The changes (delta) obtained by serial measurements of the MELD score, HARI, and PVv were analyzed through scatter plots. Bivariate correlation analysis yielded a new positive linear correlation between the delta-HARI and the delta-MELD score (r = 0.469; p < 0.001). In addition, our data revealed a new negative linear correlation between delta-PVv and the delta-MELD score (r = -0.279, p = 0.001). The leading cause of MICU mortality was acute-on-chronic liver failure (ACLF). A subgroup analysis of patients with liver cirrhosis revealed a positive linear correlation between the delta-HARI and the delta-CLIF-C-ACLF score (r = 0.252, p = 0.005). Of clinical relevance, non-survivors of ACLF exhibited a significantly higher mean value for the delta-HARI (0.010 vs. -0.005; p = 0.015) and a lower mean value for the delta-PVv (-0.7 vs. 1.9 cm/s; p = 0.037) in comparison to survivors of ACLF.

Conclusion

This study shows the prognostic value of the assessment of hepatic perfusion in critical care patients with severe liver diseases by bedside Doppler ultrasound examination and its utility as an accurate predictor of the outcome in patients with ACLF. Increasing HARI and a decreasing PVv are predictors of an adverse outcome. Delta-HARI and delta-PVv are new biomarkers of prognosis and ACLF-related mortality in patients with liver diseases. Delta-HARI and delta-PVv may be helpful in guiding clinical decision-making, especially in catecholamine and fluid management.

Use of Human Albumin Administration for the Prevention and Treatment of Hyponatremia in Patients with Liver Cirrhosis: A Systematic Review and Meta-Analysis

Background. Hyponatremia is a common complication of liver cirrhosis and aggravates patients’ outcomes. It may be corrected by human albumin (HA) infusion. Herein, we have conducted a systematic review and meta-analysis to evaluate the efficacy of intravenous HA administration for the prevention and treatment of hyponatremia in liver cirrhosis. Methods. Literature was searched in the PubMed, EMBASE, and Cochrane Library databases. If possible, a meta-analysis would be conducted. Incidence of hyponatremia, rate of resolution of hyponatremia, and serum sodium level were compared between cirrhotic patients who received and did not receive HA infusion. Odds ratios (ORs) or mean differences (MDs) with 95% confidence intervals (CIs) were calculated. The quality of evidence was assessed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Results. Initially, 3231 papers were identified. Among them, 30 studies, including 25 randomized controlled trials (RCTs) and 5 cohort studies, were eligible. Among cirrhotic patients without hyponatremia, the HA infusion group had significantly lower incidence of hyponatremia (OR = 0.55, 95%CI = 0.38–0.80, p = 0.001) and higher serum sodium level (MD = 0.95, 95%CI = 0.47–1.43, p = 0.0001) as compared to the control group. Among cirrhotic patients with hyponatremia, the HA infusion group had a significantly higher rate of resolution of hyponatremia (OR = 1.50, 95%CI = 1.17–1.92, p = 0.001) as compared to the control group. Generally, the quality of available evidence is low. Conclusions. Based on the current evidence, HA may be considered for preventing the development of hyponatremia in liver cirrhosis, especially in those undergoing LVP, and treating hyponatremia. Well-designed studies are required to clarify the effects of HA infusion on hyponatremia in liver cirrhosis.

Incidental finding of elevated pulmonary arterial pressures during liver transplantation and postoperative pulmonary complications

BACKGROUND

In patients with end stage liver disease (ESLD) scheduled for liver transplantation (LT), an intraoperative incidental finding of elevated mean pulmonary arterial pressure (mPAP) may be observed. Its association with patient outcome has not been evaluated. We aimed to estimate the effects of an incidental finding of a mPAP > 20 mmHg during LT on the incidence of pulmonary complications.

METHODS

We examined all patients who underwent a LT at Paul-Brousse hospital between January 1,2015 and December 31,2020. Those who received: a LT due to acute liver failure, a combined transplantation, or a retransplantation were excluded, as well as patients for whom known porto-pulmonary hypertension was treated before the LT or patients who underwent a LT for other etiologies than ESLD. Using right sided pulmonary artery catheterization measurements made following anesthesia induction, the study cohort was divided into two groups using a mPAP cutoff of 20 mmHg. The primary outcome was a composite of pulmonary complications. Univariate and multivariable logistic regression analyses were performed to identify variables associated with the primary outcome. Sensitivity analyses of multivariable models were also conducted with other mPAP cutoffs (mPAP ≥ 25 mmHg and ≥ 35 mmHg) and even with mPAP as a continuous variable.

RESULTS

Of 942 patients who underwent a LT, 659 met our inclusion criteria. Among them, 446 patients (67.7%) presented with an elevated mPAP (mPAP of 26.4 ± 5.9 mmHg). When adjusted for confounding factors, an elevated mPAP was not associated with a higher risk of pulmonary complications (adjusted OR: 1.16; 95%CI 0.8-1.7), nor with 90 days-mortality or any other complications. In our sensitivity analyses, we observed a lower prevalence of elevated mPAP when increasing thresholds (235 patients (35.7%) had an elevated mPAP when defined as ≥ 25 mmHg and 41 patients (6.2%) had an elevated mPAP when defined as ≥ 35 mmHg). We did not observe consistent association between a mPAP ≥ 25 mmHg or a mPAP ≥ 35 mmHg and our outcomes.

CONCLUSION

Incidental finding of elevated mPAP was highly prevalent during LT, but it was not associated with a higher risk of postoperative complications.

Cell-To-Cell Communication in the Resistance Vasculature

The arterial vasculature can be divided into large conduit arteries, intermediate contractile arteries, resistance arteries, arterioles, and capillaries. Resistance arteries and arterioles primarily function to control systemic blood pressure. The resistance arteries are composed of a layer of endothelial cells oriented parallel to the direction of blood flow, which are separated by a matrix layer termed the internal elastic lamina from several layers of smooth muscle cells oriented perpendicular to the direction of blood flow. Cells within the vessel walls communicate in a homocellular and heterocellular fashion to govern luminal diameter, arterial resistance, and blood pressure. At rest, potassium currents govern the basal state of endothelial and smooth muscle cells. Multiple stimuli can elicit rises in intracellular calcium levels in either endothelial cells or smooth muscle cells, sourced from intracellular stores such as the endoplasmic reticulum or the extracellular space. In general, activation of endothelial cells results in the production of a vasodilatory signal, usually in the form of nitric oxide or endothelial-derived hyperpolarization. Conversely, activation of smooth muscle cells results in a vasoconstriction response through smooth muscle cell contraction. © 2022 American Physiological Society. Compr Physiol 12: 1-35, 2022.

Prognostic value of blood pressure and resting heart rate in patients with tricuspid regurgitation

Background

The prognostic value of blood pressure (BP) and resting heart rate (RHR) in tricuspid regurgitation (TR) patients is unknown.

Aims

This study aimed to investigate the associations of BP and RHR with all-cause mortality in patients with TR.

Methods

A total of 2,013 patients with moderate or severe TR underwent echocardiography and BP measurement. The associations of routinely measured BP and RHR with 2-year all-cause mortality were analyzed.

Results

The cohort had 45.9% male patients and a mean age of 62.5 ± 15.9 years. At the 2-year follow-up, 165 patient deaths had occurred. The risk of death decreased rapidly, negatively correlating with systolic blood pressure (SBP) up to 120 mmHg and diastolic blood pressure (DBP) up to 70 mmHg. For RHR, the risk increased in direct proportion, starting at 80 beats per min. After adjusting for age, sex, body mass index (BMI), diabetes, coronary heart disease, pulmonary hypertension, estimated glomerular filtration rate (eGFR), and NYHA class, SBP [hazard ratio (HR):0.89; 95% CI:0.823-0.957 per 10 mmHg increase; P =0.002], DBP (HR:0.8; 95% CI:0.714-0.908 per 10 mmHg increase; P < 0.001), and RHR (HR: 1.1; 95% CI: 1.022-1.175 per 10 beats per min increase; P = 0.011) were independently associated with all-cause mortality. These associations persisted after further adjustments for echocardiographic indices, medications, serological tests, and etiologies.

Conclusion

In this cohort of patients with TR, routinely measured BP and RHR were associated with all-cause mortality independently. However, further large-scale, high-quality studies are required to validate our findings.

Cardiac risk stratification of the liver transplant candidate: A comprehensive review

Cardiovascular diseases (CVD) form a principal consideration in patients with end-stage liver disease (ESLD) undergoing evaluation for liver transplant (LT) with prognostic implications in the peri- and post-transplant periods. As the predominant etiology of ESLD continues to evolve, addressing CVD in these patients has become increasingly relevant. Likewise, as the number of LTs increase by the year, the proportion of older adults on the waiting list with competing comorbidities increase, and the demographics of LT candidates evolve with parallel increases in their CVD risk profiles. The primary goal of cardiac risk assessment is to preemptively reduce the risk of cardiovascular morbidity and mortality that may arise from hemodynamic stress in the peri- and post-transplant periods. The complex hemodynamics shared by ESLD patients in the pre-transplant period with adverse cardiovascular events occurring in only some of these recipients continue to challenge currently available guidelines and their uniform applicability. This review focusses on cardiac assessment of LT candidates in a stepwise manner with special emphasis on preoperative patient optimization. We hope that this will reinforce the importance of cardiovascular optimization prior to LT, prevent futile LT in those with advanced CVD beyond the stage of optimization, and thereby use the finite resources prudently.

Hepatorenal Syndrome: Pathophysiology

Hepatorenal syndrome (HRS) is defined as a functional renal failure without major histologic changes in individuals with severe liver disease and it is associated with a high mortality rate. Renal hypoperfusion due to marked vasoconstriction as a result of complex circulatory dysfunction has been suggested to be the cornerstone of HRS. Splanchnic and peripheral arterial vasodilation and cirrhotic cardiomyopathy result in effective arterial hypovolemia and compensatory activation of vasoconstrictor mechanisms. The efficacy of current therapeutic strategies targeting this circulatory dysfunction is limited. Increasing evidence suggests a substantial role of systemic inflammation in HRS via either vascular or direct renal effects. Here we summarize the current understanding of HRS pathophysiology.

IMMUNOHISTOCHEMICAL ASSESSMENT OF LYMPHATIC VESSELS IN HUMAN LIVERS WITH CHRONIC HEPATITIS C - RELATION TO HISTOLOGICAL VARIABLES

ABSTRACT Background Viral hepatitis C is a significant public health challenge. The disease may remain clinically silent in both acute and chronic forms, and chronic infections may progress to advanced disease such as cirrhosis and hepatocellular carcinoma, requiring costly treatment, compromising the patient’s quality of life and even leading to death. For this reason, it is one of the most frequent indications for liver transplantation. Although treatment with direct-acting antivirals represents remarkable progress, many patients are still infected and even those who cleared the viral infection must be followed due to their previous hepatic lesions, especially regarding the disturbances of lobular architecture and the sanguineal and lymphatic vessels. Objective To assess immunohistochemical aspects of lymphatic sprouts and mature lymphatic vascularity with histological variables of liver injury attributable to hepatitis C virus (HCV) and fatty disease. Methods The present study included 72 liver biopsies of cases with chronic hepatitis C. Morphologic changes reflecting “staging” and “activity” were analyzed. Immunohistochemical reactions were performed with monoclonal antibody D2-40 anti-podoplanin. Major histological variables were also semiquantified so as to enable the search for possible associations among histological and Immunohistochemical criteria, as well as with genotypes 1 and 3 of HCV. Results Histological findings showed that the different degrees of strutural changes were well represented in this casuistic. Intralobular/parenchymal necro-inflammatory activity was predominantly mild to moderate. Most cases did not show major evidences of fatty disease, which was found significantly higher in cases infected with HCV genotype 3. The amount of portal lymphatic sprouts increased along with the progression of structural changes, maximal at cirrhosis. Portal lymphatic sprouts as well as portal mature lymphatic vessels also showed an increase parallel to the increase in the degree of portal/septal inflammatory infiltrate. In the present study, no significant association was found between the proportion of portal lymphatic sprouts or portal mature lymphatic vessels and the degree of periportal/periseptal activity. No significant relations were detected between lymphatic sprouts/mature vessels and periportal or parenchymal inflammatory activity, nor with infections due to HCV genotype 1 or 3. Conclusion Visualization and semiquantitation of sprouts and mature lymphatic vessels were clearly yielded by Immunohistochemical staining with monoclonal antibody D2-40. The amount of lymphatics was increased along fibrogenic process, significantly related to progression of liver disease and maximal at cirrhosis. No significant relations were detected with necro-inflammatory activity at interface or in the parenchyma.

Effect of liver resection-induced increases in hepatic venous pressure gradient on development of postoperative acute kidney injury

BACKGROUND

The impact of changes in portal pressure before and after liver resection (defined as ΔHVPG) on postoperative kidney function remains unknown. Therefore, we investigated the effect of ΔHVPG on (i) the incidence of postoperative AKI and (ii) the renin-angiotensin system (RAAS) and sympathetic nervous system (SNS) activity.

METHODS

We included 30 patients undergoing partial liver resection. Our primary outcome was postoperative AKI according to KDIGO criteria. For our secondary outcome we assessed the plasma renin, aldosterone, noradrenaline, adrenaline, dopamine and vasopressin concentrations prior and 2 h after induction of anaesthesia, on the first and fifth postoperative day. HVPG was measured prior and immediately after liver resection.

RESULTS

ΔHVPG could be measured in 21 patients with 12 patients HVPG showing increases in HVPG (∆HVPG≥1 mmHg) while 9 patients remained stable. AKI developed in 7/12 of patients with increasing HVPG, but only in 2/9 of patients with stable ΔHVPG (p = 0.302). Noradrenalin levels were significantly higher in patients with increasing ΔHVPG than in patients with stable ΔHVPG. (p = 0.009). Biomarkers reflecting RAAS and SNS activity remained similar in patients with increasing vs. stable ΔHVPG.

CONCLUSIONS

Patients with increased HVPG had higher postoperative creatinine concentrations, however, the incidence of AKI was similar between patients with increased versus stable HVPG.

Clinical Implications, Evaluation, and Management of Hyponatremia in Cirrhosis

Hyponatremia is the most common electrolyte abnormality in patients with decompensated cirrhosis on Liver Transplantation (LT) waiting list. Most of these patients have dilutional or hypervolemic hyponatremia secondary to splanchnic vasodilatation. Excessive secretion of the antidiuretic hormone also plays an important role. Hypervolemic hyponatremia is commonly associated with refractory ascites, spontaneous bacterial peritonitis, and hepatic encephalopathy. Although uncommon, the use of diuretics and laxatives can cause hypovolemic hyponatremia that is characterized by the striking absence of ascites or pedal edema. Clinical features are often nonspecific and depend on the acuity of onset rather than the absolute value of serum sodium. Symptoms may be subtle, including nausea, lethargy, weakness, or anorexia. However, rarely patients may present with confusion, seizures, psychosis, or coma. Treatment includes discontinuation of diuretics, beta-blockers, and albumin infusion. Hypertonic saline (3%) infusion may be used in patients with very low serum sodium (<110 mmol/L) or when patients present with seizures or coma. Short-term use of Vasopressin (V₂) receptor antagonists may also be used to normalize sodium levels prior to LT. However, all these measures may be futile, and LT remains the definite treatment in these patients to improve survival. In this review, we describe the classification, pathogenesis of hyponatremia, and its clinical implications in patients with cirrhosis. Approach to these patients along with management will also be discussed briefly.

Pre-operative TIPS may reduce post-operative ACLF occurrence

Background & Aims

Acute-on-chronic liver failure (ACLF) is a syndrome associated with organ failure and high short-term mortality. Recently, the role of surgery as a precipitating event for ACLF has been characterised. However, the impact of preoperative transjugular intrahepatic portosystemic shunt (TIPS) placement on ACLF development in patients with cirrhosis undergoing surgery has not been investigated yet.

Methods

A total of 926 patients (363 with cirrhosis undergoing surgery and 563 patients with TIPS) were screened. Forty-five patients with preoperative TIPS (TIPS group) were 1:1 propensity matched to patients without preoperative TIPS (no-TIPS group). The primary endpoint was the development of ACLF within 28 and 90 days after surgery. The secondary endpoint was 1-year mortality. Results were confirmed by a differently 1:2 matched cohort (n = 176).

Results

Patients in the no-TIPS group had significantly higher rates of ACLF within 28 days (29 vs. 9%; p = 0.016) and 90 days (33 vs. 13%; p = 0.020) after surgery as well as significantly higher 1-year mortality (38 vs. 18%; p = 0.023) compared with those in the TIPS group. Surgery without preoperative TIPS and Chronic Liver Failure Consortium–Acute Decompensation (CLIF-C AD) score were independent predictors for 28- and 90-day ACLF development and 1-year mortality after surgery, especially in patients undergoing visceral surgery. In the no-TIPS group, a CLIF-C AD score of >45 could be identified as cut-off for patients at risk for postoperative ACLF development benefiting from TIPS.

Conclusions

This study suggests that preoperative TIPS may result in lower rates of postoperative ACLF development especially in patients undergoing visceral surgery and with a CLIF-C AD score above 45.

Lay summary

Acute-on-chronic liver failure (ACLF) is a syndrome that is associated with high short-term mortality. Surgical procedures are a known precipitating event for ACLF. This study investigates the role of preoperative insertion of a transjugular intrahepatic portosystemic shunt (TIPS) on postoperative mortality and ACLF development. Patients with TIPS insertion before a surgical procedure exhibit improved postoperative survival and lower rates of postoperative ACLF, especially in patients undergoing visceral surgery and with a high CLIF-C AD prognostic score. Thus, this study suggests preoperative TIPS insertion in those high-risk patients.

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This study investigates the impact of preoperative TIPS on postsurgical ACLF.

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Patients with preoperative TIPS, especially before visceral surgery, develop significantly lower rates of ACLF.

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Preoperative TIPS is associated with improved postsurgical survival.

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CLIF-C AD score >45 can be used as cut-off for patients at risk for postsurgical ACLF.

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Selected patients might benefit from preoperative TIPS insertion.

Portal venous pressure in non-cirrhotic bilharzial patients undergoing elective splenectomy, can it affect mortality? A prospective study

Background and study aims

To evaluate the impact of intraoperatively measured portal vein pressure (PVP) on mortality in non-cirrhotic bilharzial patients undergoing splenectomy.

Methods

The present study is a prospective study that was conducted in Egypt from April 2014 to April 2018. Adult patients with non-cirrhotic bilharziasis who were scheduled to undergo splenectomy were included. Studied cases were divided into a survival cohort and a non-survival cohort. The main objective was the correlation between the incidence of mortality and intraoperative PVP.

Results

The present work comprised 130 cases with a mean age of 51.8 ± 6.4 years old. The in-hospital mortality rate was 22.3%, with sepsis as a major cause of death (37.9%). In term of the association between preoperative variables and mortality, survivors had statistically significant lower portal vein diameter (13.6 ± 1.8 versus 15.2 ± 1.8mm; p<0.001) and higher portal vein velocity (14.2 ± 1.8 versus 10.4 ± 2.3 cm/sec; p<0.001) than nonsurvivors. The survived patients had significantly lower PVP (13.9 ± 1.1 versus 17.7 ± 2.7; p<0.001). A cut-off value of ≥14.5 mmHg, the PVP yielded a sensitivity of 86.2% and a specificity of 69% for the prediction of mortality. The association analysis showed a statistically significant association between mortality and postoperative liver function parameters.

Conclusions

High intraoperative PVP is linked to early postoperative death in non-cirrhotic cases undergoing splenectomy. Our study showed that PVP > 14.5mmHg was an independent predictor of death and showed good diagnostic performance for the detection of early postoperative mortality.

Perioperative right ventricular function and dysfunction in adult cardiac surgery-focused review (part 2-management of right ventricular failure)

The single most important factor in improving outcomes in right ventricular (RV) failure is anticipating and recognizing it. Once established, a vicious circle of systemic hypotension, and RV ischemia and dilation, occurs, leading to cardiogenic shock, multi-organ failure, and death. RV dysfunction and failure theoretically can occur in three settings-increase in the pre-load; increase in after load; and decrease in contractility. For patients deemed low risk for the development of RV failure, when it occurs, the correction of underlying cause is the most important and effective treatment strategy. Therapy of RV failure must focus on improving the RV coronary perfusion, lowering pulmonary vascular resistance, and optimizing the pre-load. Pre-load and after-load optimization, ventilator adjustments, and improving the contractility of RV by inotropes are the first line of therapy and should be initiated early to prevent multi-organ damage. Mechanical assist device implantation or circulatory support with extracorporeal membrane oxygenation (ECMO) may be needed in refractory cases.

Critically Ill COVID-19 Patient with Chronic Liver Disease - Insights into a Comprehensive Liver Intensive Care

The novel coronavirus-related coronavirus disease 2019 (COVID-19) pandemic has been relentless in disrupting and overwhelming healthcare the world over. Clinical outcomes of COVID-19 in patients with chronic comorbidities, especially in those with metabolic syndrome, are well documented. Chronic liver disease and cirrhosis patients are a special sub-group, among whom the management of COVID-19 is challenging. Understanding the pathophysiology of COVID-19 in patients with cirrhosis and portal hypertension improves our identification of at-risk patients for disease progression that will further help compartmentalize generalized and specialized treatment options in this special patient group. In this exhaustive review, we critically review the impact of COVID-19 on the liver and in chronic liver disease and cirrhosis patients. We further discuss common features associated with the pathophysiology of COVID-19 and cirrhosis, based on the renin-angiotensin system and deliberate current literature on guidelines for the treatment of COVID-19 and extrapolate the same to the cirrhosis population to provide a concise and stepwise, evidence-based management for cirrhosis patients with severe and critical COVID-19. There are no specific management guidelines for cirrhosis patients with COVID-19 and current recommendations for treatment are as per guidelines for general population. Nevertheless, specific issues like avoiding corticosteroids in decompensated patients with variceal bleeding, suspected sepsis, high grade hepatic encephalopathy and acute kidney injury, use of early mechanical ventilation strategies in those with severe ascites and hepatopulmonary syndrome, avoidance of remdesivir in advanced liver disease, and application of liver-specific severity scores for prognostication and identification of futility need to be highlighted.

Cardiac output states in patients with severe functional tricuspid regurgitation: impact on treatment success and prognosis

AIMS

To investigate whether there is evidence for distinct cardiac output (CO) based phenotypes in patients with chronic right heart failure associated with severe tricuspid regurgitation (TR) and to characterize their impact on TR treatment and outcome.

METHODS AND RESULTS

A total of 132 patients underwent isolated transcatheter tricuspid valve repair (TTVR) for functional TR at two centres. Patients were clustered according to k-means clustering into low [cardiac index (CI) < 1.7 L/min/m² ], intermediate (CI 1.7-2.6 L/min/m² ) and high CO (CI > 2.6 L/min/m² ) clusters. All-cause mortality and clinical characteristics during follow-up were compared among different CO clusters. Mortality rates were highest for patients in a low (24%) and high CO state (42%, log-rank P < 0.001). High CO state patients were characterized by larger inferior vena cava diameters (P = 0.003), reduced liver function, higher incidence of ascites (P = 0.006) and markedly reduced systemic vascular resistance (P < 0.001) as compared to TTVR patients in other CO states. Despite comparable procedural success rates, the extent of changes in right atrial pressures (P = 0.01) and right ventricular dimensions (P < 0.001) per decrease in regurgitant volume following TTVR was less pronounced in high CO state patients as compared to other CO states. Successful TTVR was associated with the smallest prognostic benefit among low and high CO state patients.

CONCLUSIONS

Patients with chronic right heart failure and severe TR display distinct CO states. The high CO state is characterized by advanced congestive hepatopathy, a substantial decrease in peripheral vascular tone, a lack of response of central venous pressures to TR reduction, and worse prognosis. These data are relevant to the pathophysiological understanding and management of this important clinical syndrome.

Renal replacement therapy as bridging-to-recovery in refractory hepatorenal syndrome

A 50-year-old female patient with cirrhosis due to alcoholic steatohepatitis was referred to our department because of recurrent hepatorenal syndrome (HRS) and hepatic hydrothorax. Clinically, severe anasarca was the leading problem. In contrast to previous episodes, HRS did not respond to standard treatment including terlipressin.Given the severe, refractory hyperhydration, we finally initiated renal replacement therapy (RRT). Subsequently, RRT was performed without severe side effects for more than 100 days. In the meantime, liver function remarkably improved, most probably due to the prolonged abstinence from alcohol. Finally, RRT could be stopped. Since then, our patient has remained in good clinical condition for more than 6 months, with well-compensated Child-Pugh stage A cirrhosis and only mild chronic kidney disease stage III.In conclusion, this case highlights that RRT may be considered in individual cases as bridging therapy in refractory HRS until the liver regenerates due to the absence of damaging mechanisms.

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.

Terlipressin has stood the test of time: Clinical overview in 2020 and future perspectives

Vasoactive drugs form the mainstay of therapy for two of the most important complications of liver disease: hepatorenal syndrome (HRS) and acute variceal bleed (AVB). With cumulative evidence supporting the use in cirrhosis, terlipressin has been recommended for the management of HRS and AVB. However, owing to the safety concerns, terlipressin was not approved by food and drug administration (FDA) until now. In this review, we discuss the pharmacology and the major practice-changing studies on the safety and efficacy of terlipressin in patients with cirrhosis particularly focusing on existing indications like AVB and HRS and reviewing new data on the expanding indications in liver disease. The references for this review were identified from PUBMED with MeSH terms such as "terlipressin," "hepatorenal syndrome," "varices, esophagal and gastric," "ascites" and "cirrhosis." Terlipressin, a synthetic analogue of vasopressin, was introduced in 1975 to overcome the adverse effects of vasopressin. Terlipressin is an effective drug for HRS reversal in patients with liver cirrhosis and acute-on-chronic liver failure. There is documented mortality benefit with terlipressin therapy in HRS and AVB. Adverse effects are common with terlipressin and need to be monitored strictly. There is some evidence to support the use of this drug in refractory ascites, hepatic hydrothorax, paracentesis-induced circulatory dysfunction and perioperatively during liver transplantation. However, terlipressin is not yet recommended for such indications. In conclusion, terlipressin has stood the test of time with expanding indications and clear prerequisites for clinical use. Our review warrants a fresh perspective on the efficacy and safety of terlipressin.

Natremia and liver transplantation: The right amount of salt for a good recipe

An adequate balance between electrolytes and clear water is of paramount importance to maintaining physiologic homeostasis. Natremia imbalance and, in particular, hyponatremia is the most frequent electrolyte abnormality observed in hospitalized subjects, involving approximately one-fourth of them. Pathological changes occurring during liver cirrhosis predispose patients to an increased risk of sodium imbalance, and hypervolemic hyponatremia has been reported in nearly 50% of subjects with severe liver disease and ascites. Splanchnic vasodilatation, portal-systemic collaterals’ opening and increased excretion of vasoactive modulators are all factors impairing clear water handling during liver cirrhosis. Of concern, sodium imbalance has been consistently reported to be associated with increased risk of complications and reduced survival in liver disease patients. In the last decades clinical interest in sodium levels has been also extended in the field of liver transplantation. Evidence that [Na⁺] in blood is an independent risk factor for in-list mortality led to the incorporation of sodium value in prognostic scores employed for transplant priority, such as model for end-stage liver disease-Na and UKELD. On the other hand, severe hyponatremic cirrhotic patients are frequently delisted by transplant centers due to the elevated risk of mortality after grafting. In this review, we describe in detail the relationship between sodium imbalance and liver cirrhosis, focusing on its impact on peritransplant phases. The possible therapeutic approaches, in order to improve transplant outcome, are also discussed. 

Hyponatremia in Cirrhosis: An Update

Hyponatremia is frequently seen in patients with ascites secondary to advanced cirrhosis and portal hypertension. Although not apparent in the early stages of cirrhosis, the progression of cirrhosis and portal hypertension leads to splanchnic vasodilation, and this leads to the activation of compensatory mechanisms such as renin-angiotensin-aldosterone system (RAAS), sympathetic nervous system, and antidiuretic hormone (ADH) to ameliorate low circulatory volume. The net effect is the avid retention of sodium and water to compensate for the low effective circulatory volume, resulting in the development of ascites. These compensatory mechanisms lead to impairment of the kidneys to eliminate solute-free water in decompensated cirrhosis. Nonosmotic secretion of antidiuretic hormone (ADH), also known as arginine vasopressin, further worsens excess water retention and thereby hyponatremia. The management of hyponatremia in this setting is a challenge as conventional therapies for hyponatremia including fluid restriction and correction of hypokalemia are frequently inefficacious. In this review, we discuss the pathophysiology, complications, and various treatment modalities, including albumin infusion, selective vasopressin receptor antagonists, or hypertonic saline for patients with severe hyponatremia and those awaiting liver transplantation.

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.

Pentadecapeptide BPC 157 resolves Pringle maneuver in rats, both ischemia and reperfusion

BACKGROUND

The Pringle maneuver [portal triad obstruction(PTO)] provides huge disturbances during ischemia and even more thereafter in reperfusion. Contrarily, a possible solution may be stable gastric pentadecapeptide BPC 157, with already documented beneficial effects in ischemia/reperfusion conditions. Recently, BPC 157, as a cytoprotective agent, successfully resolved vessel occlusions in rats (ischemic colitis; deep vein thrombosis, superior anterior pancreaticoduodenal vein; bile duct cirrhosis) through rapid collateral vessel recruitment to circumvent vessel occlusion. Thereby, medication BPC 157 regimens were administered as a single challenge before and during ischemia or, alternatively, at various time points during reperfusion.

AIM

To introduce BPC 157 therapy against pringle maneuver-damage.

METHODS

In deeply anesthetised rats, the portal triad was clamped up for 30 min. Rats then underwent reperfusion for either 15 min or 24 h. Medication [(10 µg, 10 ng/kg) regimens, administered as a single challenge] picked (a) ischemia, PTO period [at 5 min before (ip) or at 5 or 30 min of ligation time (as a bath to PTO)] or (b) reperfusion, post-PTO period [at 1 or 15 min (bath during surgery) or 24 h (ip) reperfusion-time]. We provided gross, microscopy, malondialdehyde, serum enzymes, electrocardiogram, portal, caval, and aortal pressure, thrombosis and venography assessments.

RESULTS

BPC 157 counteracts electrocardiogram disturbances (increased P wave amplitude, S1Q3T3 QRS pattern and tachycardia). Rapidly presented vascular pathway (portal vein-superior mesenteric vein-inferior mesenteric vein-rectal veins-left ileal vein-inferior caval vein) as the adequate shunting immediately affected disturbed haemodynamics. Portal hypertension and severe aortal hypotension during PTO, as well as portal and caval hypertension and mild aortal hypotension in reperfusion and refractory ascites formation were markedly attenuated (during PTO) or completely abrogated (reperfusion); thrombosis in portal vein tributaries and inferior caval vein or hepatic artery was counteracted during portal triad obstruction PTO. Also, counteraction included the whole vicious injurious circle [i.e., lung pathology (severe capillary congestion), liver (dilated central veins and terminal portal venules), intestine (substantial capillary congestion, submucosal oedema, loss of villous architecture), splenomegaly, right heart (picked P wave values)] regularly perpetuated in ischemia and progressed by reperfusion in Pringle rats.

CONCLUSION

BPC 157 resolves pringle maneuver-damage in rats, both for ischemia and reperfusion.

Pentadecapeptide BPC 157 resolves suprahepatic occlusion of the inferior caval vein, Budd-Chiari syndrome model in rats

BACKGROUND

Recently, as a possible therapy resolving solution, pentadecapeptide BPC 157 therapy, has been used in alleviating various vascular occlusion disturbances. BPC 157 was previously reviewed as novel mediator of Robert cytoprotection and endothelium protection in the stomach, and gut-brain axis, beneficial therapy in gastrointestinal tract, with particular reference to vascular recruitment, ulcerative colitis and tumor cachexia, and other tissues healing. Here we raised new hypothesis about BPC 157 therapy in the Budd-Chiari syndrome in rats, rapid bypassing of the suprahepatic inferior caval vein occlusion, and rats recovery with the active and effective pharmacotherapy treatment.

AIM

To investigate Budd-Chiari syndrome model (inferior caval vein suprahepatic occlusion) resolution, since BPC 157 resolves various rat vascular occlusion.

METHODS

We assessed the activated bypassing pathways between the inferior and superior caval veins and portocaval shunt, counteracted caval/portal hypertension, aortal hypotension, venous/arterial thrombosis, electrocardiogram disturbances, liver and gastrointestinal lesions (i.e., stomach and duodenum hemorrhages, in particular, congestion). Rats with suprahepatic occlusion of the inferior vena cava by ligation were medicated at 1 min, 15 min, 24 h, or 48 h post-ligation. Medication consisted of 10 µg/kg BPC 157, 10 ng BPC 157 or 5 mL/kg saline, administered once as an abdominal bath or intragastric application. Gross and microscopic observations were made, in addition to assessments of electrical activity of the heart (electrocardiogram), portal and caval hypertension, aortal hypotension, thrombosis, hepatomegaly, splenomegaly and venography. Furthermore, levels of nitric oxide, malondialdehyde in the liver and serum enzymes were determined.

RESULTS

BPC 157 counteracted increased P wave amplitude, tachycardia and ST-elevation, i.e., right heart failure from acute thrombotic coronary occlusion. The bypassing pathway of the inferior vena cava-azygos (hemiazygos) vein-superior vena cava and portocaval shunt occurred rapidly. Even with severe caval ˃ portal hypertension, BPC 157 antagonized portal and caval hypertension and aortal hypotension, and also reduced refractory ascites. Thrombosis of portal vein tributaries, inferior vena cava, and hepatic and coronary arteries was attenuated. In addition, there was reduced pathology of the lungs (severe capillary congestion) and liver (dilated central veins and terminal portal venules), decreased intestine hemorrhagic lesions (substantial capillary congestion, submucosal edema and architecture loss), and increased liver and spleen weight. During the period of ligation, nitric oxide- and malondialdehyde-levels in the liver remained within normal healthy values, and increases in serum enzymes were markedly reduced.

CONCLUSION

BPC 157 counteracts Budd Chiari syndrome in rats.

Restoration of liver sinusoidal cell phenotypes by statins improves portal hypertension and histology in rats with NASH

Non-alcoholic steatohepatitis (NASH) is a common chronic liver disorder in developed countries, with the associated clinical complications driven by portal hypertension (PH). PH may precede fibrosis development, probably due to endothelial dysfunction at early stages of the disease. Our aim was to characterize liver sinusoidal endothelial cell (LSEC) dedifferentiation/capillarization and its contribution to PH in NASH, together with assessing statins capability to revert endothelial function improving early NASH stages. Sprague-Dawley rats were fed with high fat glucose-fructose diet (HFGFD), or control diet (CD) for 8 weeks and then treated with simvastatin (sim) (10 mg·kg⁻¹·day⁻¹), atorvastatin (ato) (10 mg·kg⁻¹·day⁻¹) or vehicle during 2 weeks. Biochemical, histological and hemodynamic determinations were carried out. Sinusoidal endothelial dysfunction was assessed in individualized sorted LSEC and hepatic stellate cells (HSC) from animal groups and in whole liver samples. HFGFD rats showed full NASH features without fibrosis but with significantly increased portal pressure compared with CD rats (10.47 ± 0.37 mmHg vs 8.30 ± 0.22 mmHg; p < 0.001). Moreover, HFGFD rats showed a higher percentage of capillarized (CD32b⁻/CD11b⁻) LSEC (8% vs 1%, p = 0.005) showing a contractile phenotype associated to HSC activation. Statin treatments caused a significant portal pressure reduction (sim: 9.29 ± 0.25 mmHg, p < 0.01; ato: 8.85 ± 0.30 mmHg, p < 0.001), NASH histology reversion, along with significant recovery of LSEC differentiation and a regression of HSC activation to a more quiescent phenotype. In an early NASH model without fibrosis with PH, LSEC transition to capillarization and HSC activation are reverted by statin treatment inducing portal pressure decrease and NASH features improvement.

Endothelin-converting enzyme-1 expression in acute and chronic liver injury in fibrogenesis

Endothelin-1 (ET-1) induces contraction, proliferation, and collagen synthesis of activated hepatic stellate cells and is a potent mediator of portal hypertension. Endothelin-converting enzyme-1 (ECE-1) generates ET-1 from the inactive precursor big-endothelin-1. The cellular distribution and activity of ECE-1 in the liver is unknown. Hepatic fibrogenesis was induced in rats by CCl₄ administration and secondary biliary cirrhosis after 6 weeks of complete bile duct occlusion (BDO). The tissue ET-1 and ET receptor protein levels were quantified, the ECE-1 isoform mRNAs were measured by RNase protection assay and ECE-1 activity was analyzed. ECE-1a and -b mRNA were upregulated in biliary cirrhosis and in CCl₄-injured livers, whereas ECE-1c mRNA remained unchanged. ECE-1 activity was increased after BDO and peaked at 12 h after acute CCl₄-intoxication. Tissue levels of ET-1, ET_A- and ET_B receptors were elevated 7-, 5-, and 4.6-fold in cirrhotic rats, respectively. ECE-1 activity increased following BDO and acute CCl₄-intoxication. In conclusion, ECE-1a and -b RNAs are upregulated in fibrogenesis, indicating that these isoforms play a central role in ET-1 generation during fibrogenesis and portal hypertension.

Activation of the Alternate Renin-Angiotensin System Correlates with the Clinical Status in Human Cirrhosis and Corrects Post Liver Transplantation

Introduction: Recent animal studies have shown that the alternate renin-angiotensin system (RAS) consisting of angiotensin-converting enzyme 2 (ACE2), angiotensin-(1–7) (Ang-(1–7)) and the Mas receptor is upregulated in cirrhosis and contributes to splanchnic vasodilatation and portal hypertension. To determine the potential relevance of these findings to human liver disease, we evaluated its expression and relationship to the patients’ clinical status in subjects with cirrhosis. Methods: Blood sampling from peripheral and central vascular beds was performed intra-operatively for cirrhotic patients at the time of liver transplantation (LT) or trans-jugular intra-hepatic portosystemic shunt (TIPS) procedures to measure angiotensin II (Ang II) and Ang-(1–7) peptide levels and ACE and ACE2 enzyme activity. Relevant clinical and hemodynamic data were recorded pre-operatively for all subjects and peripheral blood sampling was repeated 3 months or later post-operatively. Results: Ang-(1–-7) and ACE2 activity were up-regulated more than twofold in cirrhotic subjects both at the time of LT and TIPS and levels returned to comparable levels as control subjects post-transplantation. Ang-(1–7) levels correlated positively with the degree of liver disease severity, as measured by the model for an end-stage liver disease (MELD) and also with clinical parameters of pathological vasodilatation including cardiac output (CO). There were strong correlations found between the ACE2:ACE and the Ang-(1–7):Ang II ratio highlighting the inter-dependence of the alternate and classical arms of the RAS and thus their potential impact on vascular tone. Conclusions: In human cirrhosis, the alternate RAS is markedly upregulated and the activation of this system is associated strongly with features of the hyperdynamic circulation in advanced human cirrhosis.

Acute kidney injury in children with chronic liver disease

Acute kidney injury (AKI) is a common accompaniment in patients with liver disease. The causes, risk factors, manifestations and management of AKI in these patients vary according to the liver disease in question (acute liver failure, acute-on-chronic liver failure, post-liver transplantation or metabolic liver disease). There are multiple causes of AKI in patients with liver disease-pre-renal, acute tubular necrosis, post-renal, drug-induced renal failure and hepatorenal syndrome (HRS). Definitions of AKI in liver failure are periodically revised and updated, but pediatric definitions have still to see the light of the day. As our understanding of the pathophysiology of liver disease and renal involvement improves, treatment modalities have become more advanced and rationalized. Treatment includes reversing precipitating factors, such as infections and gastrointestinal bleeding, volume expansion, paracentesis and vasoconstrictors. This approach is tried and tested in adults. A pediatric tailored approach is still lacking due to inadequate numbers of patients, differences in causes of AKI and paucity of literature. In this review, we attempt to explore the pathophysiological basis, treatment modalities and controversies in the diagnosis and treatment of AKI in pediatric patients with chronic liver disease and discuss our own personal practice. We recognize that, although it is not a very commonly encountered entity in pediatric population, HRS has specific diagnostic criteria and treatment modalities that differ from other causes of AKI in patients with chronic liver disease; hence among the etiologies of kidney injury in patients with chronic liver disease, we focus here on HRS.

Serum lactate level accurately predicts mortality in critically ill patients with cirrhosis with acute kidney injury

BACKGROUND AND AIM

Serum lactate levels are routinely measured in critically ill patients with cirrhosis, and hyperlactatemia is a common finding, but its prognostic value remains controversial. Our aim was to examine whether serum lactate level could be used as a predictor of outcome in critically ill patients with cirrhosis (CICP) with acute kidney injury (AKI).

PATIENTS AND METHODS

In this study, we included 480 consecutive patients with cirrhosis admitted to ICU, complicated with AKI, and were followed up for 365 days. Patients were divided into four groups (Q1-Q4) by serum lactate quartiles: Q1≤1.8 mg/dl, Q2=1.9-2.4 mg/dl, Q3=2.5-4.0 mg/dl, and Q4≥4.1 mg/dl. The hazard ratio (HR) and 95% confidence intervals (CIs) for hospital mortality were calculated across each quartile of serum lactate, using the Q1 as reference, and four models were built to adjust for the HR of mortality.

RESULTS

Compared with patients in the survival group, nonsurvivors had higher serum lactate levels. Mortality rate increased progressively as the serum lactate level increased (Q1: 56.06%, Q2: 62.16%, Q3: 72.73% and Q4: 75.86%), and this relationship remained statistically significant after rigorous control of confounding factors in Q2, Q3, and Q4 with HRs of 1.03 (95% CI: 0.73-1.46), 1.40 (95% CI: 1.01-1.95), and 1.84 (95% CI: 1.28-2.64), respectively.

CONCLUSION

Our study brings a new perspective to the role of lactate monitoring in CICP with AKI. Elevated serum lactate levels are associated with a higher mortality rate in CICP with AKI. Elevated serum lactate levels should be part of rapid diagnosis and initiation of therapy to improve clinical outcome.

Normothermic ex-vivo liver perfusion: where do we stand and where to reach?

Nowadays liver transplantation is considered as the treatment of choice, however, the scarcity of suitable donor organs limits the delivery of care to the end-stage liver disease patients leading to the death while on the waiting list. The advent of ex-situ normothermic machine perfusion (NMP) has emerged as an alternative to the standard organ preservation technique, static cold storage (SCS). The newer technique promises to not only restore the normal metabolic activity but also attempt to recondition the marginal livers back to the pristine state, which are otherwise more susceptible to ischemic injury and foster the poor post-transplant outcomes. Areas covered: An extensive search of all the published literature describing the role of NMP based device in liver transplantation as an alternative to SCS was made on MEDLINE, EMBASE, Cochrane, BIOSIS, Crossref, Scopus databases and clinical trial registry on 10 May 2018. Expert commentary: The main tenet of NMP is the establishment of the physiological milieu, which permits aerobic metabolism to continue through out the period of preservation and limits the effects of ischemia-reperfusion (I/R) injury. In addition, by assessing the various metabolic and synthetic parameters the viability and suitability of donor livers for transplantation can be determined. This important technological advancement has scored satisfactorily on the safety and efficacy parameters in preliminary clinical studies. The present review suggests that NMP can offer the opportunity to assess and safely utilize the marginal donor livers if deemed appropriate for the transplantation. However, ongoing trials will determine its full potential and further adoption.

INVOLVEMENT OF CATECHOLAMINES IN THE MYOCARDIUM OF RATS SUBMITTED TO EXPERIMENTAL MODEL OF PORTAL HYPERTENSION

Background:

The role of autonomic nervous system in the development and maintenance of portal hypertension is not fully elucidated. It is known that the gene expression of norepinephrine in the superior mesenteric artery varies with time, and it may contribute for splanchnic vasodilation and its consequent hemodynamic repercussions. It is still not known exactly how the adrenergic expression behaves at the heart level in the initial stages of this process.

Aim:

To evaluate the immunohistochemical expression of the enzyme tyrosine hydroxylase (tyrosine 3-monooxygenase), involved in the synthesis of norepinephrine, in the myocardium of rats submitted to partial ligation of the portal vein.

Methods:

Twenty-four Wistar rats were divided into two groups: Sham Operated and Portal Hypertension. The partial ligation was performed in the Portal Hypertension group, and after 1/6/24 h and 3/5/14 days the animals were euthanized. Immunohistochemical analysis was performed to quantify the expression of the stained enzyme using the ImageJ program.

Results:

The Portal Hypertension group expressed percentages between 4.6-6% of the marked area, while the Sham Operated group varied between 4-5%. Although there was no statistical significance, the percentage stained in the Portal Hypertension group followed an increasing pattern in the first 6 h and a decreasing pattern after 24 h, which was not observed in the Sham Operated group.

Conclusion:

The expression of noradrenaline in rat myocardium during the first two weeks after partial ligation of the portal vein, with tyrosine hydroxylase as marker, did not show differences between groups over time.

Preoperative Transjugular Intrahepatic Portosystemic Shunt Placement for Extrahepatic Abdominal Surgery

Extrahepatic abdominal surgery in patients with portal hypertension is associated with a high rate of perioperative complications and death due to the increased risk of liver failure, perioperative bleeding, and ascites. One proposed method to facilitate surgery in these patients is with preoperative placement of a transjugular intrahepatic portosystemic shunt (TIPS). By decompressing the portal circulation, this presurgical measure would theoretically decrease the potential for bleeding and improve the ability to control ascites in the perioperative and postoperative period. This article reviews the use of TIPS prior to abdominal surgery in patients with portal hypertension.

β-Blocker therapy for cirrhotic cardiomyopathy: a randomized-controlled trial

BACKGROUND

Cirrhotic cardiomyopathy is characterized by an attenuated contractile response to stress. Long-term exposure of β-adrenergic receptors to persistently high levels of catecholamines has been implicated in its pathogenesis. We hypothesized that β-blockade with metoprolol could reverse the changes in heart function and morphology in cirrhotic cardiomyopathy.

PATIENTS AND METHODS

In this prospective randomized trial, we included 78 patients aged between 18 and 60 years with abnormal cardiac output response under dobutamine stress echocardiography, without primary cardiac disease or a history of alcohol intake. Patients were assigned randomly to receive metoprolol or placebo for 6 months. The primary endpoint was the improvement in cardiac output response to stress, measured by an increase in the left ventricle stroke volume more than 30%.

RESULTS

Three (7.3%) patients in the metoprolol group and nine (24.3%) patients in the placebo group showed improved stroke volume (P=0.057). Diastolic dysfunction was found in two (4.8%) patients before and in five (15.6%) patients after therapy in the metoprolol group, and in 10 (27%) patients before and nine (31%) patients after therapy in the placebo group (P=0.67). After treatment, no echocardiography parameter of morphology was significantly different between metoprolol or placebo groups. No significant differences were observed in noradrenaline, plasma renin activity, and troponin levels between groups. Cirrhosis-related clinical events, including hospitalizations and mortality, were not significantly different between the two groups. Six months of therapy with β-blocker did not ameliorate heart function and morphology in patients with cirrhotic cardiomyopathy.

Systemic hemodynamic response to terlipressin predicts development of hepatorenal syndrome and survival in advanced cirrhosis

BACKGROUND

The aim of this study was to predict the occurrence of hepatorenal syndrome (HRS) and death in patients with advanced cirrhosis and ascites.

PATIENTS AND METHODS

We retrospectively evaluated 2-year data of 78 patients with cirrhosis and ascites (Child-Pugh B/C: 45/43). The mean arterial pressure (MAP) and cardiac output (CO) were measured in all patients just before administration of 2 mg of terlipressin and 30 min later. Systemic vascular resistance (SVR) was calculated as MAP/CO. ΔMAP, and ΔCO, and ΔSVR were defined as the percentage change of MAP, CO, and SVR, respectively, after terlipressin injection. Plasma renin activity (PRA) and plasma aldosterone were evaluated at baseline. Two multivariate models were used: one excluding (model 1) and one including (model 2) the Model of End-stage Liver Disease score.

RESULTS

Higher ΔSVR, Model of End-stage Liver Disease score, and PRA were related independently to the severity of cirrhosis. Independent predictors of HRS at 12 and 24 months were ΔSVR (models 1/2: P=0.008/0.01 and 0.01/0.02, respectively), ΔCO (models 1/2: P=0.01/0.03 and 0.03/0.04, respectively), and PRA (models 1/2: P=0.04 and model 1: P=0.04, respectively). ΔSVR at 12 and 24 months (models 1/2: P=0.005/0.01 and 0.01/0.03, respectively) and ΔCO at 24 months (models 1/2: P=0.02/0.01, respectively) were related independently to survival. Patient groups with significantly higher probability of HRS and mortality were identified by certain cutoffs of ΔSVR (20.6 and 22.8%, respectively) and ΔCO (-10.6 and -11.8%, respectively). ΔSVR and ΔCO independently predicted survival in patients with the most advanced cirrhosis and infection-related survival.

CONCLUSION

An increase in SVR by at least 20% and a decrease in CO at least 10% in response to terlipressin could predict HRS and mortality in patients with advanced cirrhosis.

Cardiac diseases among liver transplant candidates

Improvements in early survival after liver transplant (LT) have allowed for the selection of LT candidates with multiple comorbidities. Cardiovascular disease is a major contributor to post-LT complications. We performed a literature search to identify the causes of cardiac disease in the LT population and to describe techniques for diagnosis and perioperative management. As no definite guidelines for preoperative assessment (except for pulmonary heart disease) are currently available, we recommend an algorithm for preoperative cardiac work-up.

Portopulmonary hypertension in children: a rare but potentially lethal and under-recognized disease

Portopulmonary hypertension (PoPH) is defined by the combination of portal hypertension and precapillary pulmonary arterial hypertension (PAH). Very little is known about this process in pediatric patients but prognosis is generally poor. We review our institutional experience and report on five patients with pediatric PoPH. The median age of PoPH diagnosis was six years and PAH was 14 years. PAH diagnosis was made by echocardiogram in all patients, four of whom also had cardiac catheterization. The median mean pulmonary artery pressure (mPAP) was 48.5 mmHg (interquartile range [IQR] = 46–60) with a median pulmonary vascular resistance index (PVRi) of 9 WU*M² (IQR = 8–22). All were acute pulmonary vasodilator testing non-responsive. All patients received targeted therapies. Three of five patients (60%) died despite an evidence-based approach to care. Of those who died, timing from the PoPH diagnosis to death ranged from three days to three years. Based upon our limited experience, PoPH is a disorder with significant mortality in childhood and challenges in treatment. Future research, focused on screening and early targeted treatment strategies, may alter the current dismal prognosis for these children.

A Novel Predictor of Posttransplant Portal Hypertension in Adult-To-Adult Living Donor Liver Transplantation: Increased Estimated Spleen/Graft Volume Ratio

BACKGROUND

In adult living donor liver transplantation (ALDLT), graft-to-recipient weight ratio of less than 0.8 is incomplete for predicting portal hypertension (>20 mm Hg) after reperfusion. We aimed to identify preoperative factors contributing to portal venous pressure (PVP) after reperfusion and to predict portal hypertension, focusing on spleen volume-to-graft volume ratio (SVGVR).

METHODS

In 73 recipients with ALDLT between 2002 and 2013, first we analyzed survival according to PVP of 20 mm Hg as the threshold, evaluating the efficacy of splenectomy. Second, we evaluated various preoperative factors contributing to portal hypertension after reperfusion.

RESULTS

All of the recipients with PVP greater than 20 mm Hg (n = 19) underwent PVP modulation by splenectomy, and their overall survival was favorable compared with 54 recipients who did not need splenectomy (PVP ≤ 20 mm Hg). Graft-to-recipient weight ratio had no correlation with PVP.Multivariate analysis revealed that estimated graft and spleen volume were significant factors contributing to PVP after reperfusion (P < 0.0001 and P < 0.0001, respectively). Furthermore, estimated SVGVR showed a significant negative correlation to PVP after reperfusion (R = 0.652), and the best cutoff value for portal hypertension was 0.95.

CONCLUSIONS

In ALDLT, preoperative assessment of SVGVR is a good predictor of portal hypertension after reperfusion can be used to indicate the need for splenectomy before reperfusion.