"Porto-pulmonary hypertension: a comprehensive review"

Hemodynamic and Clinical Response to Liver Transplantation in Children and Young Adults POPH Patients

Portopulmonary hypertension is an intractable form of pulmonary hypertension. Although liver transplantation is recommended for patients who respond poorly to treatments, the mechanisms by which liver transplantation improves pulmonary hypertension remain unclear. The present study investigated these mechanisms by retrospectively evaluating patients' data. This study retrospectively evaluated echocardiography and catheterization data before and after liver transplantation in 12 patients who underwent liver transplantation from 2001 to 2019. The 12 patients included one male and 11 females, of median age at liver transplantation of 10 years, 2 months. Nine patients underwent liver transplantation for congenital biliary atresia and three for portal vein aplasia or hypoplasia. Mean pulmonary arterial pressure was 44.1 ± 8.1 mmHg at the first cardiac catheter examination, 35.3 ± 7.8 mmHg before liver transplantation, and 29.5 ± 9.3 mmHg 6 months after liver transplantation. Pulmonary artery pressure was reduced by treatments of pulmonary hypertension and by liver transplantation. Pulmonary vascular resistance did not differ before and after liver transplantation, whereas the cardiac index decreased significantly, indicating that the significant reduction in mean pulmonary artery pressure was due to a decrease in cardiac index. Decreased cardiac index was thought to result from improvements in hyperdynamic conditions due to increased (normalized) systemic vascular resistance. Liver transplantation likely suppresses shear stress on pulmonary arteries, preventing further damage by hyper-circulation. A longer-term evaluation is required to determine the effect of improving pulmonary artery remodeling.

Pathophysiology of Hepatorenal Syndrome

Hepatorenal syndrome type 1 (HRS-1) is a unique form of acute kidney injury that affects individuals with decompensated cirrhosis with ascites. The primary mechanism leading to reduction of kidney function in HRS-1 is hemodynamic in nature. Cumulative evidence points to a cascade of events that led to a profound reduction in kidney perfusion. A state of increased intrahepatic vascular resistance characteristic of advanced cirrhosis and portal hypertension is accompanied by maladaptive peripheral arterial vasodilation and reduction in systemic vascular resistance and mean arterial pressure. As a result of a fall in effective arterial blood volume, there is a compensatory activation of the sympathetic nervous system and the renin-angiotensin system, local renal vasoconstriction, loss of renal autoregulation, decrease in renal blood flow, and ultimately a fall in glomerular filtration rate. Systemic release of nitric oxide stimulated by the fibrotic liver, bacterial translocation, and inflammation constitute key components of the pathogenesis. While angiotensin II and noradrenaline remain the critical mediators of renal arterial and arteriolar vasoconstriction, other novel molecules have been recently implicated. Although the above-described mechanistic pathway remains the backbone of the pathogenesis of HRS-1, other noxious elements may be present in advanced cirrhosis and likely contribute to the renal impairment. Direct liver-kidney crosstalk via the hepatorenal sympathetic reflex can further reduce renal blood flow independently of the systemic derangements. Tense ascites may lead to intraabdominal hypertension and abdominal compartment syndrome. Cardio-hemodynamic processes have also been increasingly recognized. Porto-pulmonary hypertension, cirrhotic cardiomyopathy, and abdominal compartment syndrome may lead to renal congestion and complicate the course of HRS-1. In addition, a degree of ischemic or toxic (cholemic) tubular injury may overlap with the underlying circulatory dysfunction and further exacerbate the course of acute kidney injury. Improving our understanding of the pathogenesis of HRS-1 may lead to improvements in therapeutic options for this seriously ill population.

LTSI Consensus Guidelines: Preoperative Pulmonary Evaluation in Adult Liver Transplant Recipients

The relationship between chronic liver disease and respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease (CLD) have been characterized: hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. Apart from that coexisting pulmonary disease like chronic obstructive lung disease and interstitial lung disease also complicate the outcomes after liver transplantation (LT). Assessment for evaluation of underlying pulmonary disorders is essential to improve outcomes in patients with CLD, posted for LT. This consensus guideline of the Liver Transplant Society of India (LTSI) provides a comprehensive review of pulmonary issues in CLD, related and unrelated to underlying liver disease and gives recommendations for pulmonary screening in specific clinical scenarios in adults with chronic liver disease planned for LT. This document also aims to standardize the strategies for preoperative evaluation of these pulmonary issues in this subset of patients. Proposed recommendations were based on selected single case reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Additionally, this review will highlight the lacunae in our current evaluation strategy, challenges faced, and will provide direction to potentially useful futuristic preoperative evaluation strategies.

Isolated Subclinical Right Ventricle Systolic Dysfunction in Patients after Liver Transplantation

Although hemodynamic alterations in end-stage liver disease (ESLD) and its association with porto-pulmonary hypertension have been well-established, the long-term effects of ESLD on RV systolic function in patients without porto-pulmonary hypertension remain disregarded. Here we aimed to assess the long-term effect of ESLD on RV function and its relationship with the use of NSBBs and clinical, laboratory and imaging parameters in end-stage liver disease. The use of NSBBs is still controversial due to concerns about reduced cardiac contractility and the possibility of increased mortality. Thirty-four liver transplant recipients were included. Demographic characteristics, laboratory and baseline echocardiography measures were obtained. Patients were recalled for transthoracic echocardiographic evaluation after transplantation. Right ventricle dysfunction was identified by having at least one value below the reference levels of RV S’, or TAPSE. Isolated subclinical RV dysfunction was observed at 20.6% of the sample population. The present study demonstrates hemodynamic circulation in cirrhosis and increased preload and afterload might have long-term effects on RV function, even the lack of porto-pulmonary hypertension. These findings underline the significance of cardiac function follow-up in cirrhotic patients after transplantation. In this study, patients treated with propranolol seemed to have better RV function and less gastrointestinal bleeding. We speculated that preoperative propranolol treatment might help preserve RV function by providing RAS suppression, improving endothelial function and hyperdynamic circulation seen in ESLD. This potential protective relationship between the use of propranolol and RV function might improve mortality or graft-failure during OLT and after liver transplantation in patients with cirrhosis.

Consensus on the management of complications of cirrhosis of the liver in pediatrics

The Asociación Mexicana de Hepatología A.C. carried out the Consensus on the Management of Complications of Cirrhosis of the Liver in Pediatrics to provide physicians with useful information for treating said complications. A group of pediatric gastroenterologists and experts in nutrition, nephrology, and infectious diseases participated and reviewed the medical literature. The Delphi method was applied to obtain the level of agreement on the statements that were formulated. The statements were sent to the participants to be analyzed and voted upon, after which they were discussed in virtual sessions, and the final versions were produced. The aim of the consensus results was to issue indications for the management of pediatric patients with liver cirrhosis, to prevent or control complications.

Evaluation of Predisposing Metabolic Risk Factors for Portopulmonary Hypertension in Patients with NASH Cirrhosis

PURPOSE

Metabolic parameters are important for the development of portopulmonary hypertension (PoPH) during nonalcoholic steatohepatitis (NASH)-associated cirrhosis. This study evaluated patients with NASH-associated cirrhosis to determine metabolic risk factors for portopulmonary hypertension.

PATIENTS AND METHODS

Data on 171 patients (120 men and 51 women) with NASH-associated cirrhosis who were seen in Florence Nightingale Hospital's gastroenterology Clinic from 2009 to 2018 was obtained from the Hospital database. A pulmonary artery systolic pressure >35 mmHg was defined as PH (pulmonary hypertension) according to standard transthoracic echocardiography. Portal hypertension was diagnosed from clinical symptoms and dilated portal veins shown by abdominal ultrasound or computed tomography (CT). Pulmonary patients with portal hypertension were diagnosed with portopulmonary hypertension (PoPH).

RESULTS

A total of 171 patients with NASH-associated cirrhosis were included in this study. Of these, 43 patients had PoPH. These patients had increased TSH (p=0.004), bilirubin (p=0.023) and triglyceride (p=0.048) levels, higher MELD scores (p=0.018) and decreased hemoglobin (p=0.05). MELD score and hemoglobin, total bilirubin, TSH, and triglyceride levels were all included in a multivariate logistic regression model and TSH levels were independently associated with increased risk of PoPH.

CONCLUSION

Increased TSH is an independent risk factor for PoPH.

Portopulmonary hypertension: prognosis and management in the current treatment era - results from the REHAP registry

BACKGROUND

Portopulmonary hypertension (PoPH) is a rare condition with poorer survival compared to idiopathic/familial pulmonary arterial hypertension (IPAH/FPAH).

AIMS

To compare the characteristics, survival, prognostic factors and management of PoPH and IPAH/FPAH patients and to assess the impact of treatment on survival of PoPH patients.

METHODS

Analysis of data of prevalent and incident PoPH patients enrolled in the Spanish registry of PAH (REHAP) from January 1998 to December 2017 and comparison with IPAH/FPAH patients. Variables analysed: patient and disease (PAH and liver) characteristics, first-line PAH-targeted therapy, causes of death, prognostic factors and survival (according to aetiology and treatment in PoPH patients).

RESULTS

Compared to IPAH/FPAH patients (n = 678), patients with PoPH (n = 237) were predominantly men, older and had better functional class and higher prevalence of ascites. Haemodynamics were better. Biomarkers for heart failure were worse. Age- and sex-adjusted 5-year survival rate from diagnosis was 49.3% for PoPH patients and 68.7% for IPAH patients (P < 0.001). Treated PoPH had better survival than non-treated. PAH- and liver-related causes accounted for 30.2% and 24.7% of deaths in PoPH patients. PoPH patients were less likely to receive first-line PAH-targeted therapy and this was associated with greater mortality. Increasing age, worse exercise capacity and ascites were independent prognostic factors of poorer survival; first-line oral monotherapy was associated with improved survival. Eight (3.4%) PoPH patients underwent liver transplantation.

CONCLUSIONS

PoPH patients are undertreated and show poorer survival than IPAH/FPAH patients. First-line treatment with PAH-targeted therapy was associated with better survival. Presence of ascites was a predictor of mortality.

Portal hypertensive vasculopathy - An entity worth remembering with non-neoplastic gastrointestinal lesions

Portal hypertensive vasculopathy (PHV) represents an increase in the pressure in the portal circulation. This increased pressure leads to changes in the mucosa that can be appreciated endoscopically as well as histopathologically. Lesions can be observed in the entire gastrointestinal tract (GIT) including stomach, duodenum, jejunum and colon. The histological changes are appreciated mainly in the mucosal and submucosal blood vessels. A knowledge of these lesions as well as the changes helps in separating them from other close differentials with specific treatment to be instituted. The pathogenesis of the hemodynamic changes is not well-understood. The underlying factor is increased portal pressure. Studies indicate, that besides increased portal pressure other factors in combination led to the observed changes. Portal hypertensive gastropathy (PHG) is seen in the gastric body and fundus, while varices are noted in the cardia and fundus. Changes may be seen in the small intestine and throughout the colon with anorectal varices. Histopathological changes include dilated, congested and ectatic capillaries and edema in the lamina propria besides a large spectrum of other histopathological changes. Mucosal capillaries with thick irregular wall show absence of red blood cells in the lumen. Thickening of the vessel wall serves as a better marker than the vascular diameter when portal hypertension (PHT) is considered. Long standing cases may show fibrosis in lamina propria. At times, these changes may lead to occult gastrointestinal bleeding. Important differentials need to be ruled out in all the cases as the treatment and the outcome of all differs. Endoscopically or histopathologically if the mucosal changes are observed they should not be overlooked and a detailed work-up must be carried out.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Management in Liver Transplantation in the Horizon 2020

Hepatopulmonary syndrome (HPS) is characterized by intrapulmonary microvasculature dilatation that causes intrapulmonary shunting and leads to a gas exchange abnormality in the presence of liver diseases, which is the most common cause of respiratory insufficiency in these patients. HPS doubles the risk of death, and liver transplantation (LT) is the only curative therapeutic option so it should be considered in patients with severe HPS, with excellent survival rates post-LT. However, pretransplant Pao₂ <45 mm Hg has been associated with an increase in post-transplant morbidity and mortality, but it does not imply a contraindication for LT. The resolution of HPS usually occurs within 6 months post-LT, but it can take 1 year. Portopulmonary hypertension (PoPH) is defined as pulmonary arterial hypertension (PAH) that develops in the setting of portal hypertension with or without liver disease in the absence of other causes of PAH. The prevalence of PoPH is 5% to 10% among liver transplant (LT) candidates. The impact of LT on PoPH is unpredictable. Therefore, despite conferring a high morbidity and mortality, PoPH itself is not an indication for liver transplantation. It may be considered a contraindication for LT in severe cases.

Pulmonary manifestations of chronic liver disease: a comprehensive review

Hepatopulmonary syndrome (HPS) and porto-pulmonary hypertension (PoPH) represent relatively common pulmonary vascular complications of advanced liver disease. Despite distinct differences in their pathogenetic background, both clinical states are characterized by impaired arterial oxygenation and limited functional status, and are associated with increased pre-transplantation mortality. Accumulation of ascitic fluid in the pleural cavity, known as hepatic hydrothorax (HH), is another frequent manifestation of decompensated cirrhosis, which may cause severe respiratory dysfunction, depending on the volume of the effusion, the rapidity of its development and its resistance to therapeutic measures. Orthotopic liver transplantation constitutes the only effective treatment able to resolve the pulmonary complications of liver disease. A prioritization policy for liver transplantation has evolved over the past years regarding advanced stages of HPS, yielding favorable outcomes regarding post-transplantation survival and HPS resolution. In contrast, severe PoPH is associated with poor post-transplantation survival. Hence, liver transplantation is recommended only for patients with PoPH and an acceptable reduction in pulmonary pressure values, after receiving PoPH-targeted vasodilating therapy. This review focuses on basic pathogenetic and diagnostic principles and discusses the current therapeutic approaches regarding HPS, PoPH, and HH.

Portopulmonary hypertension caused by portal hypertension that is complicated by central diabetes insipidus

We discuss the pathophysiology, diagnosis, differential diagnosis, and therapy of a case with central diabetes insipidus, idiopathic portal hypertension, and portopulmonary hypertension. This report reviews how vasopressin affects those diseases.

Diagnosis and management of toxicities of immune checkpoint inhibitors in hepatocellular carcinoma

Immune checkpoint inhibitors (ICIs) have reshaped cancer therapy. ICIs enhance T cell activation through various mechanisms and may help reverse the exhausted phenotype of tumour-infiltrating lymphocytes. However, disrupting the key role that checkpoint molecules play in immune homeostasis may result in autoimmune complications. A broad range of immune-related adverse events (irAEs) involve almost every organ but mostly affect the skin, digestive system, lung, endocrine glands, nervous system, kidney, blood cells, and musculoskeletal system. They are usually manageable but can be life-threatening. The incidence of irAEs is not very different in patients with hepatocellular carcinoma (HCC) compared to other tumour types, although there is a trend towards a higher incidence of hepatic irAEs. HCC usually develops on a background of cirrhosis with associated systemic manifestations. Extrahepatic organ dysfunction in cirrhosis may cause signs and symptoms that overlap with irAEs or increase their severity. Available guidelines for the management of irAEs have not specifically considered the assessment of toxicities in the context of patients with liver cancer and cirrhosis. This review addresses the toxicity profile of ICIs in patients with HCC, focusing on the challenges that the underlying liver disease poses to their diagnosis and management. Challenges include late recognition, inadequate work-up and delayed treatment, overdiagnosis and inappropriate interruption of ICIs, complications caused by immunosuppressive therapy, and increased cost. A specific algorithm for the management of hepatic irAEs is provided.

Reappraising the spectrum of AKI and hepatorenal syndrome in patients with cirrhosis

The occurrence of acute kidney injury (AKI) in patients with end-stage liver disease constitutes one of the most challenging clinical scenarios in in-hospital and critical care medicine. Hepatorenal syndrome type 1 (HRS-1), which is a specific type of AKI that occurs in the context of advanced cirrhosis and portal hypertension, is associated with particularly high mortality. The pathogenesis of HRS-1 is largely viewed as a functional derangement that ultimately affects renal vasculature tone. However, new insights suggest that non-haemodynamic tubulo-toxic factors, such as endotoxins and bile acids, might mediate parenchymal renal injury in patients with cirrhosis, suggesting that concurrent mechanisms, including those traditionally associated with HRS-1 and non-traditional factors, might contribute to the development of AKI in patients with cirrhosis. Moreover, histological evidence of morphological abnormalities in the kidneys of patients with cirrhosis and renal dysfunction has prompted the functional nature of HRS-1 to be re-examined. From a clinical perspective, a diagnosis of HRS-1 guides utilization of vasoconstrictive therapy and decisions regarding renal replacement therapy. Patients with cirrhosis are at risk of AKI owing to a wide range of factors. However, the tools currently available to ascertain the diagnosis of HRS-1 and guide therapy are suboptimal. Short of liver transplantation, goal-directed haemodynamically targeted pharmacotherapy remains the cornerstone of treatment for this condition; improved understanding of the underlying pathogenic mechanisms might lead to better clinical outcomes. Here, we examine our current understanding of the pathophysiology of HRS-1 and existing challenges in its diagnosis and treatment.

Portopulmonary Hypertension: A Complex Case Derived from Multiple Penetrating Trauma-Induced Mesenteric Arteriovenous Fistulae

Portopulmonary hypertension (PoPH) is a well-recognized complication of portal hypertension. This study reports a case of PoPH that was secondarily caused by post-traumatic mesenteric arteriovenous fistula. A 38-year-old man with a history of knife stabbing wounds in the abdomen in 2003 was admitted to the hospital with exertional shortness of breath and a mechanic murmur over the umbilical region. Computed tomography indicated signs of PoPH and mesenteric arteriovenous fistula. Percutaneous catheter-directed embolization was first performed but failed. Subsequently, the patient was successfully treated with fistula resection and partial enterectomy. The patient had been postoperatively followed regularly, and chief symptoms had been alleviated significantly and pulmonary pressure had successfully decreased to normal range. We believe that this is the first case of PoPH caused by mesenteric arteriovenous fistula.

Prevalence and Prognosis of Portopulmonary Hypertension in 223 Liver Transplant Recipients

Objective

To investigate the prevalence and prognosis of portopulmonary hypertension (PoPH) in liver transplant recipients.

Methods

Patients with advanced liver disease who underwent orthotopic liver transplantation (OLT) were included in this retrospective study from January 2012 to June 2015. According to the 2015 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines for the diagnosis of pulmonary hypertension (PH), patients with tricuspid regurgitation velocity (TRV) >3.4 m/s or 2.9 m/s ≤ TRV ≤ 3.4 m/s coexisting with other echocardiographic PH signs were judged as PH. PH patients with portal hypertension and without other known causes of PH were diagnosed as PoPH.

Results

A total of 223 (170 males and 53 females) middle-aged (50.9 ± 9 years old) liver transplant recipients were included in this study. Fourteen patients (6.3%) were diagnosed with PoPH, and none of the patients were treated with vasodilators before or after OLT. After OLT, patients were followed up for 26 ± 13.5 months. In total, 8 of 14 (57%) PoPH patients died, and the main cause of death was pulmonary infection. Kaplan–Meier survival curves revealed a significant difference in survival between PoPH and non-PoPH patients (p < 0.001), and the median survival time after OLT of PoPH was 11.4 months.

Conclusions

The prevalence of PoPH was 6.3% in OLT recipients. The survival of untreated PoPH patients was dismal after OLT.

Mutational screening in genes related with porto-pulmonary hypertension: An analysis of 6 cases

INTRODUCTION

Portopulmonary hypertension (PPH) is a rare disease with a low incidence and without a clearly-identified genetic component. The aim of this work was to check genes and genetic modifiers related to pulmonary arterial hypertension in patients with PPH in order to clarify the molecular basis of the pathology.

PATIENTS

We selected a total of 6 patients with PPH and amplified the exonic regions and intronic flanking regions of the relevant genes and regions of interest of the genetic modifiers.

RESULTS

Six patients diagnosed with PPH were analyzed and compared to 55 healthy individuals. Potentially-pathogenic mutations were identified in the analyzed genes of 5 patients. None of these mutations, which are highly conserved throughout evolution, were detected in the control patients nor different databases analyzed (1000 Genomes, ExAC and DECIPHER). After analyzing for genetic modifiers, we found different variations that could favor the onset of the disease.

CONCLUSIONS

The genetic analysis carried out in this small cohort of patients with PPH revealed a large number of mutations, with the ENG gene showing the greatest mutational frequency.

[Portopulmonary hypertension: Updated review]

Portopulmonary hypertension (PPH) is a rare condition worldwide, although epidemiological data are unknown in Mexico. However, chronic liver diseases are very prevalent in Mexico. PPH is the 4th subtype in frequency in the group of pulmonary arterial hypertension. Its diagnosis is made within 2 scenarios: patients with suspected pulmonary hypertension and candidates for orthotopic liver transplantation (OLT). Both echocardiogram and a right cardiac catheterisation are crucial for diagnosis in both cases. PPH is a challenge for OLT, since it can significantly increase perioperative mortality. The use of specific therapy is the cornerstone of this disease, as a measure to improve the outcome of those who become candidates for OLT with moderate to severe PPH. It is important to recognise that PPH can be a contraindication to OLT. The role of lung-liver transplantation or heart-lung-liver transplantation as a measure to heal pulmonary vascular disease in patients with PPH is still uncertain.

Pulmonary complications of hepatic diseases

Severe chronic liver disease (CLD) may result from portal hypertension, hepatocellular failure or the combination of both. Some of these patients may develop pulmonary complications independent from any pulmonary pathology that they may have. Among them the hepatopulmonary syndrome (HPS), portopulmonary hypertension (PPH) and hepatic hydrothorax (HH) are described in detail in this literature review. HPS is encountered in approximately 15% to 30% of the patients and its presence is associated with increase in mortality and also requires liver transplantation in many cases. PPH has been reported among 4%-8% of the patient with CLD who have undergone liver transplantation. The HH is another entity, which has the prevalence rate of 5% to 6% and is associated in the absence of cardiopulmonary disease. These clinical syndromes occur in similar pathophysiologic environments. Most treatment modalities work as temporizing measures. The ultimate treatment of choice is liver transplant. This clinical review provides basic concepts; pathophysiology and clinical presentation that will allow the clinician to better understand these potentially life-threatening complications. This article will review up-to-date information on the pathophysiology, clinical features and the treatment of the pulmonary complications among liver disease patients.