Hepatopulmonary syndrome and portopulmonary hypertension: recent knowledge in pathogenesis and overview of clinical assessment

How non-alcoholic fatty liver disease and cirrhosis affect the heart

Liver diseases affect the heart and the vascular system. Cardiovascular complications appear to be a leading cause of death in patients with non-alcoholic fatty liver disease (NAFLD) and cirrhosis. The predominant histological changes in the liver range from steatosis to fibrosis to cirrhosis, which can each affect the cardiovascular system differently. Patients with cirrhotic cardiomyopathy (CCM) and NAFLD are at increased risk of impaired systolic and diastolic dysfunction and for suffering major cardiovascular events. However, the pathophysiological mechanisms behind these risks differ depending on the nature of the liver disease. Accurate assessment of symptoms by contemporary diagnostic modalities is essential for identifying patients at risk, for evaluating candidates for treatment, and prior to any invasive procedures. This review explores current perspectives within this field.

Transient elastography and von Willebrand factor as predictors of portal hypertension and decompensation in children

Background & Aims

Von Willebrand factor antigen (vWFAg), a protein measured to test the level of vWF released from the vascular endothelium has gained much attention as a marker for portal hypertension (PHT) severity. The objectives of this study were to investigate the use of vWFAg as a biomarker along with liver and spleen stiffness measurements by transient elastography as potential predictors of clinically significant varices (CSV), variceal bleeding (VB) and decompensation in children with PHT.

Methods

This observational prospective cohort study included 117 children (median age 10 [IQR 6-14] years) who underwent oesophagogastroduodenoscopy between January'2012 to November'2021 and a validation group of 33 children who underwent the same procedure between December'2021 to March'2023. Measurements of vWFAg and glycoprotein Ib binding activity of VWF (GPIbR) were available in 97 patients in the study group and in all patients in the validation group.Results: vWFAg and GPIbR were significantly higher in children with CSV (223 IU/dl and 166 IU/dl; p = 0.015 and p = 0.04, respectively) and VB (218 IU/dl and 174 IU/dl; p = 0.077 and p = 0.03, respectively) than in those without CSV or VB, respectively. Ninety-six patients had liver and spleen stiffness measurements. Spleen stiffness was significantly higher in patients with CSV compared to those without CSV (p = 0.003). In a chronic liver disease subgroup, a predictive scoring tool based on vWFAg, GPIbR, platelet count, and spleen/liver stiffness measurements could predict CSV with an AUROC of 0.76 (p = 0.04).

Conclusions

This study suggests the predictive value of vWF for CSV and VB increases when combined with spleen stiffness, with AUROCs of 0.88 and 0.82, respectively. Hence, a combination of biomarkers could assist clinicians in diagnosing CSV, preventing unnecessary invasive procedures.

Impacts and implications

Surveillance endoscopies in children with portal hypertension (PHT) have their own risks and non-invasive markers, such as von Willebrand factor antigen, glycoprotein Ib binding activity of VWF (GPIbR), and transient elastography could be used to predict clinically significant varices, variceal bleeding and disease compensation in children with PHT. Such non-invasive markers for PHT and varices are lacking in the paediatric population. The results show that von Willebrand factor and GPIbR along with transient elastography can be used to formulate a scoring system which can be used as a clinical tool by paediatric hepatologists to monitor the progression of PHT and risk of bleeding, and hence to stratify the performance of invasive endoscopic procedures under general anaesthesia. However, there is a need to validate the scoring system in children with portal vein thrombosis and for hepatic decompensation in a multi-centre registry in the future.

Anesthesia in patients with chronic liver disease: An updated review

Anesthesia in chronic liver disease patients can be challenging because of the medications given or interventions performed and their effects on liver physiology. Also, the effects of liver disease on coagulation and metabolism should be considered carefully. This review focuses on anesthesia in patients with different chronic liver disease stages. A literature search was performed for Scopus and PubMed databases for articles discussing different types of anesthesia in patients with chronic liver disease, their safety, usage, and risks. The choice of anesthesia is of crucial importance. Regional anesthesia, especially neuroaxial anesthesia, may benefit some patients with liver disease, but coagulopathy should be considered. Regional anesthesia provides optimum intraoperative relaxation and analgesia that extends to the postoperative period while avoiding the side effects of intravenous anesthetics and opioids. Pharmacodynamics and pharmacokinetics of anesthetic medications must guard against complications related to overdose or decreased metabolism. The choice of anesthesia in chronic liver disease patients is crucial and could be tailored according to the degree of liver compensation and the magnitude of the surgical procedure.

Pulmonary Assessment of the Liver Transplant Recipient

Respiratory symptoms and hypoxemia can complicate chronic liver disease and portal hypertension. Various pulmonary disorders affecting the pleura, lung parenchyma, and pulmonary vasculature are seen in end-stage liver disease, complicating liver transplantation (LT). Approximately 8% of cirrhotic patients in an intensive care unit develop severe pulmonary problems. These disorders affect waiting list mortality and posttransplant outcomes. A thorough history, physical examination, and appropriate laboratory tests help diagnose and assess the severity to risk stratify pulmonary diseases before LT. Hepatopulmonary syndrome (HPS), portopulmonary hypertension (POPH), and hepatic hydrothorax (HH) are respiratory consequences specific to cirrhosis and portal hypertension. HPS is seen in 5-30% of cirrhosis cases and is characterized by impaired oxygenation due to intrapulmonary vascular dilatations and arteriovenous shunts. Severe HPS is an indication of LT. The majority of patients with HPS resolve their hypoxemia after LT. When pulmonary arterial hypertension occurs in patients with portal hypertension, it is called POPH. All other causes of pulmonary arterial hypertension should be ruled out before labeling as POPH. Since severe POPH (mean pulmonary artery pressure [mPAP] >50 mm Hg) is a relative contraindication for LT, it is crucial to screen for POPH before LT. Those with moderate POPH (mPAP >35 mm Hg), who improve with medical therapy, will benefit from LT. A transudative pleural effusion called hepatic hydrothorax (HH) is seen in 5-10% of people with cirrhosis. Refractory cases of HH benefit from LT. In recent years, increasing clinical expertise and advances in the medical field have resulted in better outcomes in patients with moderate to severe pulmonary disorders, who undergo LT.

Multivisceral Transplant in a Patient With Portopulmonary Hypertension: A Case Report

Portopulmonary hypertension, a type of pulmonary arterial hypertension in the setting of cirrhotic or noncirrhotic portal hypertension, is associated with elevated morbidity and mortality during and after transplantation. Uncontrolled portopulmonary hypertension may prevent or delay listing for transplant candidates, and the prognosis without treatment and ultimately transplant is extremely poor. We present a 29-year-old White woman, who had a post-liver transplant at infancy due to biliary atresia. Later on, she developed extensive portal vein thrombosis and portopulmonary hypertension and underwent a multivisceral transplant (liver, stomach, pancreaticoduodenal complex, and small and large intestine). Preoperative mean pulmonary artery pressure was <30 mm Hg with a pulmonary vascular resistance of <300 dynes^.s/cm⁵ on oral sildenafil and intravenous epoprostenol. Intraoperatively, management required comprehensive transfusion protocols, a careful balance between correcting blood loss and preventing thrombosis. Intravenous epoprostenol, sildenafil, milrinone, and inhaled nitric oxide were used to reduce elevated mean pulmonary artery pressure and right ventricular strain associated with vascular clamping, reperfusion, and massive fluid shifts. Nitric oxide and epoprostenol use unleashed antiplatelet effects on a patient already susceptible to coagulopathy. A multimodal and multidisciplinary approach continued throughout the surgery and in the postoperative period, which led to a successful outcome.

Porto-pulmonary arterial hypertension: Translation of pathophysiological concepts to the bedside

Porto-pulmonary arterial hypertension (PoPAH) is a form of pulmonary arterial hypertension (PAH) that affects patients with cirrhosis, and - to a lesser extent - patients with non-cirrhotic liver diseases. Compared with other forms of PAH, PoPAH is more prevalent in male, in older subjects, and is characterized by lower mean pulmonary arterial pressure (mPAP) and lower pulmonary vascular resistance (PVR) with higher cardiac output. Despite more favorable hemodynamics and functional class, patients with PoPAH have a significantly worse survival than patients with other forms of PAH, likely because of liver-related events and therapeutic barriers to PAH-specific therapy. Furthermore, here cardiopulmonary and hepatic complications may affect treatment efficacy. These patients have been excluded from most randomized clinical trials testing PAH-specific treatments. To date, there is only one study investigating efficacy, safety, tolerability and pharmacokinetics of PAH-specific therapy in patients with PoPAH in a randomized placebo-controlled setting. In this trial the use of the endothelin-1 receptor antagonist macitentan showed clear hemodynamic benefit without safety concerns. However, the drug effects on functional capacity and mortality remain unclear. Here we review the current knowledge on the pathophysiology and management of PoPAH and report a case vignette of a patient with PoPAH due to hepatorenal polycystic disease.

Portopulmonary Hypertension: A Review of the Current Literature

Portopulmonary hypertension is defined as the development of pulmonary arterial hypertension in the setting of portal hypertension with or without liver cirrhosis. Portal hypertension-associated haemodynamic changes, including hyperdynamic state, portosystemic shunts and splanchnic vasodilation, induce significant alterations in pulmonary vascular bed and play a pivotal role in the pathogenesis of the disease. If left untreated, portopulmonary hypertension results in progressive right heart failure, with a poor prognosis. Although Doppler echocardiography is the best initial screening tool for symptomatic patients and liver transplantation candidates, right heart catheterisation remains the gold standard for the diagnosis of the disease. Severe portopulmonary hypertension exerts a prohibitive risk to liver transplantation by conferring an elevated perioperative mortality risk. It is important for haemodynamic parameters to correspond with non-severe portopulmonary hypertension before patients can proceed with the liver transplantation. Small uncontrolled studies and a recent randomised controlled trial have reported promising results with vasodilatory therapies in clinical and haemodynamic improvement of patients, allowing a proportion of patients to undergo liver transplantation. In this review, the epidemiology, pathogenesis, diagnostic approach and management of portopulmonary hypertension are discussed. We also highlight fields of ongoing investigation pertinent to risk stratification and optimal patient selection to maximise long-term benefit from currently available treatments.

Pulmonary Hypertension as a Rare Complication After Orthotopic Liver Transplant in a Patient With Non-alcoholic Steatohepatitis (NASH) Cirrhosis Complicated by Hepatopulmonary Syndrome

Hepatopulmonary syndrome is a phenomenon that results in an intrapulmonary shunt leading to dyspnea and hypoxemia with poor response to oxygen supplementation. It is now an indication for liver transplantation; however, some transplants result in subsequent pulmonary hypertension. Postulated mechanisms include unmasking of underlying pulmonary hypertension with liver transplant and increased pulmonary vascular resistance due to increased blood flow in hepatopulmonary syndrome. In this case, we describe pulmonary hypertension developing after orthotopic liver transplant in a cirrhotic patient with hepatopulmonary syndrome.

Acquired pulmonary arteriovenous malformation associated with bronchiectasis: a case report

Background

Pulmonary arteriovenous malformations are mostly caused by congenitally abnormal shunts between pulmonary arteries and pulmonary veins.

Case presentation

A 74-year-old Japanese woman with a history of bronchiectasis was admitted to our hospital because of dyspnea on exertion. Pulmonary angiography and reconstructed three-dimensional contrast-enhanced computed tomography images showed shunts between pulmonary arteries and pulmonary veins, indicating a diagnosis of pulmonary arteriovenous malformations. Coil embolization of the shunts was successful.

Conclusions

Our findings imply that bronchiectasis can cause pulmonary arteriovenous malformations, and thus patients who present with hypoxemia with bronchiectasis should be carefully evaluated.

Case report: Congenital extrahepatic portocaval shunt presenting as pulmonary arterial hypertension in a pregnant patient

Congenital extrahepatic portocaval shunt (CEPS) is a rare condition in which a rare congenital vascular anomaly of the portal system is present. CEPS may manifest as pulmonary arterial hypertension (PAH). When diagnosed and treated early, PAH can be reversible. We report a case of a previously asymptomatic woman, who manifested with severe pulmonary hypertension during pregnancy and was consequently diagnosed with CEPS. After unsuccessful medical treatment, urgent lung transplantation was done.

Type II Abernethy malformation in an adult male patient—a rare and reversible cause of pulmonary hypertension: a case report with review of literature

Background

Co-occurrence of Type II Abernethy malformation (AM) with Type 1 pulmonary hypertension (PH) is extremely rare. In these patients, management of AM leads to reversal of PH.

Case presentation

We report a case of 24-year-old male that presented with fever and dyspnea of insidious-onset. Initial X-ray chest revealed pulmonary edema, prominent pulmonary knuckle, and dilated right descending pulmonary artery. Two-dimensional echocardiography suggested raised pulmonary artery systolic pressure (145 mmHg) and pulmonary angiogram revealed findings suggestive of Type 1 PH. Treatment with Tab. Tadalafil-Bosentan (20/5 mg, thrice daily) was initiated, but no major relief was obtained. On day 10, dyspnea worsened. Routine ultrasound revealed splenomegaly. Further evaluation with Doppler of the portal vein was suggestive of portal hypertension, and arterial ammonia was found to be raised. Contrast-enhanced computed tomography of abdomen and pelvis demonstrated a single dilated (1.3 cm) and torturous venous shunt between right internal iliac vein and superior mesenteric vein. Thus, a definitive diagnosis of Type II AM was reached. The patient was stabilized and subjected to the shunt closure with ASD Cocoon stent graft and recovered well.

Conclusion

Our case demonstrates a rare but reversible cause of PH. Type II AM should be included in the differential diagnosis of a patient presenting with dyspnea and provisionally diagnosed as a case of PH.

M2 macrophage accumulation contributes to pulmonary fibrosis, vascular dilatation, and hypoxemia in rat hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) markedly increases the mortality of patients. However, its pathogenesis remains incompletely understood. Rat HPS develops in common bile duct ligation (CBDL)-induced, but not thioacetamide (TAA)-induced cirrhosis. We investigated the mechanisms of HPS by comparing these two models. Pulmonary histology, blood gas exchange, and the related signals regulating macrophage accumulation were assessed in CBDL and TAA rats. Anti-polymorphonuclear leukocyte (antiPMN) and anti-granulocyte-macrophage colony stimulating factor (antiGM-CSF) antibodies, clodronate liposomes (CL), and monocyte chemoattractant protein 1 (MCP1) inhibitor (bindarit) were administrated in CBDL rats, GM-CSF, and MCP1 were administrated in bone marrow-derived macrophages (BMDMs). Pulmonary inflammatory cell recruitment, vascular dilatation, and hypoxemia were progressively developed by 1 week after CBDL, but only occurred at 4 week after TAA. Neutrophils were the primary inflammatory cells within 3 weeks after CBDL and at 4 week after TAA. M2 macrophages were the primary inflammatory cells, meantime, pulmonary fibrosis, GM-CSFR, and CCR2 were specifically increased from 4 week after CBDL. AntiPMN antibody treatment decreased neutrophil and macrophage accumulation, CL or the combination of antiGM-CSF antibody and bindarit treatment decreased macrophage recruitment, resulting in pulmonary fibrosis, vascular dilatation, and hypoxemia in CBDL rats alleviated. The combination treatment of GM-CSF and MCP1 promoted cell migration, M2 macrophage differentiation, and transforming growth factor-β1 (TGF-β1) production in BMDMs. Conclusively, our results highlight neutrophil recruitment mediates pulmonary vascular dilatation and hypoxemia in the early stage of rat HPS. Further, M2 macrophage accumulation induced by GM-CSF/GM-CSFR and MCP1/CCR2 leads to pulmonary fibrosis and promotes vascular dilatation and hypoxemia, as a result, HPS develops.

Diagnosis of Hepatopulmonary Syndrome in a Large Integrated Health System

BACKGROUND & AIMS

Data on the accuracy of the diagnosis of hepatopulmonary syndrome (HPS) in cirrhosis is limited. We evaluated the clinical characteristics of patients with International Classification of Diseases (ICD) codes for hepatopulmonary syndrome (HPS) in a large integrated health system.

METHODS

A retrospective review of encounters was performed of all patients with ICD-9-CM and/or ICD-10-CM diagnosis of cirrhosis and HPS from 2014-2019 in a multi-state health system. Demographics and cardiopulmonary testing closest to the time of HPS diagnosis were recorded. HPS was defined using standard criteria.

RESULTS

A total of 42,749 unique individuals with cirrhosis were identified. An ICD diagnosis of HPS was found in 194 patients (0.45%), of which 182 had clinically confirmed cirrhosis. 143 (78.5%) underwent contrast-enhanced transthoracic echocardiography, and 98 (54%) had delayed shunting. Among them, 61 patients had a documented arterial blood gas, with 53 showing abnormal oxygenation (A-a gradient of >15 mm Hg). 12 were excluded due to significant pulmonary function test abnormalities and abnormal oxygenation from other cardiopulmonary diseases. Ultimately, 41 (22.5%) fulfilled the criteria for HPS. When stratifying those with an ICD code diagnosis of HPS into HPS, no HPS and indeterminate HPS groups, based on standard diagnostic criteria for HPS, we found that the confirmed HPS patients had similar complications except for less portopulmonary hypertension, worse gas exchange, less cardiopulmonary disease and were more often diagnosed in transplant centers.

CONCLUSIONS

The diagnosis of HPS by ICD code is made in an extremely small subset of a sizeable cirrhotic cohort. When made, only a minority of these patients meet diagnostic criteria. Our findings highlight the need for improved education and more effective screening algorithms.

The Gut-Liver Axis in Chronic Liver Disease: A Macrophage Perspective

Chronic liver disease (CLD) is a growing health concern which accounts for two million deaths per year. Obesity, alcohol overconsumption, and progressive cholestasis are commonly characterized by persistent low-grade inflammation and advancing fibrosis, which form the basis for development of end-stage liver disease complications, including hepatocellular carcinoma. CLD pathophysiology extends to the intestinal tract and is characterized by intestinal dysbiosis, bile acid dysregulation, and gut barrier disruption. In addition, macrophages are key players in CLD progression and intestinal barrier breakdown. Emerging studies are unveiling macrophage heterogeneity and driving factors of their plasticity in health and disease. To date, in-depth investigation of how gut-liver axis disruption impacts the hepatic and intestinal macrophage pool in CLD pathogenesis is scarce. In this review, we give an overview of the role of intestinal and hepatic macrophages in homeostasis and gut-liver axis disruption in progressive stages of CLD.

Ventricular septal defect with pulmonary arterial hypertension in an infant: Is there something more than what meets the eye?

An 11-month-old girl was detected to have muscular ventricular septal defect with hyperkinetic pulmonary hypertension (PH) was urgently operated upon. On follow-up, her PH worsened, resulting in right ventricular dysfunction and was later detected to have absent portal vein.

Prevalence and Associated Factors of Portopulmonary Hypertension in Patients with Portal Hypertension: A Case-Control Study

Background and Aims

There are few studies on the prevalence and clinical characteristics of portopulmonary hypertension (POPH) in patients with portal hypertension. In addition, invasive right heart catheterization further limits the clinical diagnosis of POPH patients.

Methods

From January 2018 to December 2019, 1004 patients with portal hypertension were treated in the Department of Hepatology, the First Hospital of Jilin University. Based on the inclusion and exclusion criteria, 188 patients with portal hypertension were finally included. We collected complete clinical data, laboratory examinations, and imaging examinations. Patients were divided into a POPH group and a non-POPH group based on echocardiographic results. We calculated the prevalence of POPH in patients with portal hypertension. The differences in clinical characteristics of the two groups of patients were compared.

Results

The prevalence of POPH in patients with portal hypertension was 2.8%. Among the 188 patients with portal hypertension with fingertip oxygen saturation < 95% at rest, 28 patients had POPH (12 males and 16 females), with an average age of 63 ± 8, and 160 patients did not have POPH (110 males, 50 women), with an average age of 59 ± 11. The proportion of women in the POPH group (P < 0.01) and patients without liver cancer (P = 0.044) was high. Compared to patients without POPH, patients with POPH had lower hemoglobin (related to the severity of anemia, P < 0.01), higher creatinine (P < 0.05), and lower partial pressure of oxygen and carbon dioxide (P < 0.05). Patients with POPH had a higher incidence of atrial enlargement, ventricular enlargement, mitral valve regurgitation, tricuspid regurgitation, pulmonary artery widening, pericardial effusion, and aortic regurgitation than those without POPH. The risk of POPH did not increase with the aggravation of the Child-Pugh classification.

Conclusion

The prevalence of POPH in patients with portal hypertension is 2.8%. The proportion of women and nonliver cancer in POPH patients was higher than that in non-POPH patients. In addition, the POPH group had higher creatinine and lower hemoglobin, and echocardiography showed that POPH patients had more cardiac structural changes. In patients with portal hypertension, the risk in patients with POPH has nothing to do with the Child-Pugh classification and MELD score.

A Case of Hypopituitarism Complicated by Non-Alcoholic Steatohepatitis and Severe Pulmonary Hypertension

BACKGROUND Pulmonary arterial hypertension (PAH), which is caused by increased pulmonary artery pressure, results in right-heart failure and presents with shortness of breath, chest pain, and syncope. PAH has idiopathic, heritable, and drug/toxin causes and is accompanied by other conditions, including connective tissue disease, congenital heart disease, and portal hypertension. Rarely, portal hypertension causes a type of PAH called portopulmonary hypertension (POPH). Portal hypertension can be triggered by liver cirrhosis, which can result from non-alcoholic steatohepatitis (NASH), a metabolic syndrome caused by hypopituitarism. Although an association between hypopituitarism and POPH has been suggested, few reports have described this relationship. CASE REPORT A 43-year-old woman with hypopituitarism received hormone replacement therapy after partial hypothalamic resection at age 4 years. At age 32 years, she developed liver cirrhosis from NASH due to adult growth hormone (GH) deficiency. Despite restarting GH replacement therapy, she refused the required GH doses for economic reasons. She was hospitalized with abdominal pain and dyspnea and was found to have severe POPH. She received PAH-specific therapies, including endothelin receptor antagonist and prostacyclin analog. Pulmonary hypertension improved on day 3 of hospitalization while the cardiac index increased gradually. On day 12, her respiratory status rapidly worsened and percutaneous cardiopulmonary support was applied. On day 18, she died of multiple organ failure and disseminated intravascular coagulation despite intensive care management. CONCLUSIONS Severe PAH, particularly POPH, remains incurable despite the use of PAH-specific therapies and intensive care management. For hypopituitarism patients, careful observation, including of the cardiopulmonary system, can improve the prognosis after completing hormone replacement therapy.

Pulmonary Complications in Candidates for Liver Transplantation

The liver plays a pivotal role in maintaining the homeostasis of various organ systems. Also, end-stage liver disease and its complications are major causes of morbidity and mortality among adults. Individuals who develop a chronic liver disease are at increased risk of progression to multi-organ dysfunction, including the pulmonary system. The clinical complications of pulmonary problems related to the presence of liver disease range from mild (such as hypoxemia) to life-threatening diseases (such as portopulmonary hypertension and hepatopulmonary syndrome). Herein, the major pulmonary complications related to liver cirrhosis and considerations for performing liver transplantation are reviewed.

Pathophysiological-based treatments of complications of cirrhosis

Detailed knowledge and understanding of the pathophysiological mechanisms and changes in hepatic and splanchnic function leading to the development of haemodynamic changes and portal hypertension in patients with cirrhosis are essential since it guides the search for targets to ameliorate liver-related abnormalities. Recent research has focused on the gut-liver axis, changes in intestinal permeability, translocation of bacterial products, and inflammation as important drivers of haemodynamic alterations and thereby targets for treatment. Additionally, treatment strategies should focus on microbiotic modulation, antiangiogenics, anti-inflammatory strategies, and modulation of bile acid metabolism. This paper aims to review contemporary pathophysiological-based treatment principles of the major complications of cirrhosis and portal hypertension and future targets for treatment.

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.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Impact of liver damage on blood-borne variables and pulmonary hemodynamic responses to hypoxia and hyperoxia in anesthetized rats

BACKGROUND

Liver disorders may be associated with normal pulmonary hemodynamic, hepatopulmonary syndrome (HPS), or portopulmonary hypertension (POPH). In this study, we aimed to investigate the effect of the severity of liver dysfunctions on blood-borne variables, and pulmonary hemodynamic during repeated ventilation with hyperoxic and hypoxic gases.

METHODS

Female Sprague Dawley rats were assigned into four groups of Sham (n = 7), portal vein ligation (PPVL, n = 7), common bile duct ligation (CBDL, n = 7), and combination of them (CBDL+ PPVL, n = 7). Twenty-eight days later, right ventricular systolic pressure (RVSP) and systemic blood pressure were recorded in anesthetized animals subjected to repeated maneuvers of hyperoxia (O₂ 50%) and hypoxia (O₂ 10%). Besides, we assessed blood parameters and liver histology.

RESULTS

Liver histology score, liver enzymes, WBC and plasma malondialdehyde in the CBDL+PPVL group were higher than those in the CBDL group. Also, the plasma platelet level in the CBDL+PPVL group was lower than those in the other groups. On the other hand, the serum estradiol in the CBDL group was higher than that in the CBDL+PPVL group. All the above parameters in the PPVL group were similar to those in the Sham group. During ventilation with hyperoxia gas, RVSP in the CBDL+PPVL group was higher than the ones in the other groups, and in the CBDL group, it was more than those in the PPVL and Sham groups. Hypoxic pulmonary vasoconstriction (HPV) was not detected in both CBDL+PPVL and CBDL groups, whereas, it retained in the PPVL group.

CONCLUSION

Severe liver damage increases RVSP in the CBDL+PPVL group linked to the high level of ROS, low levels of serum estradiol and platelets or a combination of them. Furthermore, the high RVSP at the noted group could present a reliable animal model for POPH in female rats.

Pulmonary Hypertension that Developed During Treatment for Hepatopulmonary Syndrome and Pulmonary Arteriovenous Malformation

Hepatopulmonary syndrome (HPS) and pulmonary arteriovenous malformation (PAVM) are hypoxemic diseases caused by right-to-left shunting but are rarely concomitant with pulmonary hypertension (PH). A 66-year-old woman with chronic hepatitis C was scheduled to undergo liver transplantation. She was referred to our department for hypoxia and an abnormal shadow in the right lung found on a preoperative examination. She was diagnosed with HPS and a PAVM in the right middle lobe. After liver transplantation, PH temporarily developed, but the pulmonary arterial pressure normalized after coil embolization. Combined HPS and PAVM may cause unique changes in pulmonary hemodynamics during treatment.

Pulmonary arterial hypertension caused by congenital extrahepatic portocaval shunt: a case report

BACKGROUND

Congenital extrahepatic portocaval shunt (CEPS), also known as Abernethy malformation, is an extremely rare anomaly of the splanchnic venous system, especially when accompanied by pulmonary arterial hypertension.

CASE PRESENTATION

We report a case of a 15-year-old female who was diagnosed with CEPS (Abernethy type Ib) accompanied by pulmonary arterial hypertension. This case was incidentally identified during abdominal ultrasound examination and confirmed by mesenteric and splenic arteriography. During more than 4 years of follow-up, after receiving sildenafil (80 mg/day), the patient's condition improved in the first year after discharge. However, one year later, the patient's conditions start to deteriorate.

CONCLUSION

This article presents a rare case of Abernethy malformation accompanied by pulmonary arterial hypertension, which can be diagnosed by using abdominal ultrasonography, portal vein computed tomography angiography or mesenteric and splenic arteriography. This malformation had limited treatment and poor prognosis.

Does Portopulmonary Hypertension Impede Liver Transplantation in Cirrhotic Patients? A French Multicentric Retrospective Study

BACKGROUND

Portopulmonary hypertension is defined by the presence of pulmonary arterial hypertension associated with portal hypertension. Its presence is a major stake for cirrhotic patients requiring liver transplantation (LT), with increased postoperative mortality and unpredictable evolution after transplantation. The aim was to study outcomes after liver transplantation in patients with portopulmonary hypertension and to identify factors associated with normalization of pulmonary hypertension.

METHODS

Patients with portopulmonary hypertension who underwent LT between 2008 and 2016 in 8 French centers were retrospectively included. Pulmonary artery pressure was established by right heart catheterization before and after LT. Primary endpoint was the normalization of pulmonary artery pressure after LT.

RESULTS

Twenty-three patients who received liver transplant between 2008 and 2016 were included. Two (8.7%) patients died in the immediate posttransplant period from right heart failure. With appropriate vasoactive medical treatment and LT, pulmonary arterial pressure was normalized in 14 patients (60.8%), demonstrating recovery from portopulmonary hypertension. In univariate analysis, the use of vasoactive combination therapy was the only prognostic factor for pulmonary arterial hypertension normalization after LT.

CONCLUSIONS

Treatment of portopulmonary hypertension with a combination of vasoactive drugs allows LT with acceptable postoperative cardiovascular-related mortality and normalization of pulmonary hypertension in the majority of the patients.

Association between cirrhosis and aneurysmal subarachnoid hemorrhage

Objective

Cirrhosis has been associated with nontraumatic subarachnoid hemorrhage (SAH). We sought to evaluate the specific association between cirrhosis and aneurysmal SAH.

Methods

We performed a retrospective cohort study using a sample of Medicare claims data from 2008 to 2015. Cirrhosis was defined using a validated ICD‐9‐CM diagnosis code algorithm. Nontraumatic SAH was identified using a validated approach requiring an inpatient claim for its ICD‐9‐CM diagnosis code. Additionally, we required the presence of an ICD‐9‐CM procedure code reflecting treatment of a cerebral aneurysm during the same hospitalization to ensure ascertainment of aneurysmal SAH specifically. We used survival statistics to calculate incidence rates and Cox proportional hazards models to evaluate the association between cirrhosis and aneurysmal SAH after adjustment for demographics, stroke risk factors, and comorbidities.

Results

We identified 10,658 (0.6%) patients with cirrhosis from among the 1,778,604 beneficiaries in our sample. The mean age of patients with cirrhosis was 73.5 (±7.8) years, and 48% were female. Over a mean of 4.7 (±2.1) years of follow‐up, 4,272 patients were hospitalized with aneurysmal SAH. The annual incidence of aneurysmal SAH in patients with cirrhosis was 0.12% (95% confidence interval [CI], 0.08–0.17%) compared to 0.05% (95% CI, 0.05–0.05%) in patients without cirrhosis. In the adjusted model, cirrhosis was independently associated with aneurysmal SAH (hazard ratio, 2.2; 95% confidence interval, 1.5–3.4).

Interpretation

Cirrhosis was independently associated with an increased risk of aneurysmal SAH among older individuals. Confirmation of these findings may yield opportunities for risk stratification and prevention.

Pulmonary Arterial Pressure Management Based on Oral Medicine for Pediatric Living Donor Liver Transplant With Portopulmonary Hypertension

Pediatric living donor liver transplantation (LDLT) in patients with advanced portopulmonary hypertension (PoPH) is associated with poor prognoses. Recently, novel oral medications, including endothelin receptor antagonists (ERAs), phosphodiesterase 5 (PDE5) inhibitors, and oral prostacyclin (PGI2) have been used to treat PoPH. Pediatric patients with PoPH who underwent LDLT from 2006 to 2016 were enrolled. Oral pulmonary hypertension (PH) medication was administered to control pulmonary arterial pressure (PAP). Four patients had PoPH. Their ages ranged from 6 to 16 years, and their original diseases were biliary atresia (n = 2), portal vein obstruction (n = 1), and intrahepatic portal systemic shunt (n = 1). For preoperative management, 2 patients received continuous intravenous PGI2 and 2 oral medications (an ERA alone or an ERA and a PDE5 inhibitor), and 2 received only oral drugs (an ERA and a PDE5 inhibitor). One patient managed only with intravenous PGI2 died. In the remaining 3 cases, intravenous PGI2 or NO was discontinued before the end of the first postoperative week. Postoperative medications were oral PGI2 alone (n = 1), an ERA alone (n = 1), or the combination of an ERA and a PDE5 inhibitor (n = 1). An ERA was the first-line therapy, and a PDE5 inhibitor was added if there was no effect. New oral PH medications were effective and safe for use in pediatric patients following LDLT. In particular, these new oral drugs prevent the need for central catheter access to infuse PGI2.

Screening for Hepatopulmonary Syndrome in Cirrhotic Patients Using Technetium 99m-macroaggregated Albumin Perfusion Lung Scan (Tc-MAA): Diagnostic Approach and Clinical Correlations

BACKGROUND AND AIMS

The aims of this study were to prospectively screen cirrhotic patients with arterial blood gas test and albumin perfusion scan, identify those fulfilling the classic hepatopulmonary syndrome (HPS) criteria, correlate with clinical parameters, and evaluate the survival of patients with HPS compared with those without HPS in a genetically homogenous Cretan cirrhotic population.

MATERIALS AND METHODS

Data on consecutive 102 patients within 1 year were collected and analyzed. All patients underwent a technetium 99m-macroaggregated albumin perfusion lung scan (Tc-MAA). Diagnosis of HPS was based on the presence of the quantitative index Tc-MAA≥6% and a [P(A-a)O2]≥15 mm Hg (≥20 mm Hg for patients over >64 y).

RESULTS

In 94/102 patients, complete scintigraphic data were available. In total, 24 (26%) patients fulfilled the diagnostic criteria of HPS; 95.8% of them had mild-to-moderate HPS. In 8 patients the Tc-MAA scintigraphy could not be interpreted. There was no difference in HPS between decompensated (24.6%) and compensated cirrhosis (27.3%). In the multivariate analysis only the quantitative index was significant for the diagnosis of HPS (P=0.001, odds ratio; 95% confidence interval, 7.05; 2.27-21.87). Kaplan- Meier survival curves indicated a similar overall prognosis for patients diagnosed with HPS (P=0.105).

CONCLUSIONS

HPS is a frequent complication of cirrhosis. Mild-to-moderate HPS has no significant effect on survival of cirrhotic patients. The quantitative Tc-MAA test is a reliable tool for diagnosis.

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.

Placental growth factor inhibition targets pulmonary angiogenesis and represents a therapy for hepatopulmonary syndrome in mice

Hepatopulmonary syndrome (HPS) is a severe complication of cirrhosis with increased risk of mortality. Pulmonary microvascular alterations are key features of HPS; but underlying mechanisms are incompletely understood, and studies on HPS are limited to rats. Placental growth factor (PlGF), a proangiogenic molecule that is selectively involved in pathological angiogenesis, may play an important role in HPS development; however, its role has never been investigated. In this study, we validated an HPS model by common bile duct ligation (CBDL) in mice, investigated the kinetic changes in pulmonary angiogenesis and inflammation during HPS development, and provide evidence for a novel therapeutic strategy by targeting pathological angiogenesis. Mice with CBDL developed hypoxemia and intrapulmonary shunting on a background of liver fibrosis. Pulmonary alterations included increased levels of proangiogenic and inflammatory markers, which was confirmed in serum of human HPS patients. Increased PlGF production in HPS mice originated from alveolar type II cells and lung macrophages, as demonstrated by immunofluorescent staining. Dysfunctional vessel formation in CBDL mice was visualized by microscopy on vascular corrosion casts. Both prophylactic and therapeutic anti-PlGF (αPlGF) antibody treatment impeded HPS development, as demonstrated by significantly less intrapulmonary shunting and improved gas exchange. αPlGF treatment decreased endothelial cell dysfunction in vivo and in vitro and was accompanied by reduced pulmonary inflammation. Importantly, αPlGF therapy did not affect liver alterations, supporting αPlGF's ability to directly target the pulmonary compartment.

CONCLUSION

CBDL in mice induces HPS, which is mediated by PlGF production; αPlGF treatment improves experimental HPS by counteracting pulmonary angiogenesis and might be an attractive therapeutic strategy for human HPS. (Hepatology 2017).

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.

Raised plasma levels of H2S and nitrate predict intrapulmonary vascular dilations: A preliminary report in patients with cryptogenic cirrhosis

BACKGROUND AND AIMS

The role of vasoactive chemicals in the pathogenesis of hepatopulmonary syndrome (HPS), a disorder characterized by intrapulmonary vascular dilation (IPVD), is only vaguely elucidated. We aimed to study the association between plasma H₂S, nitrate levels, and presence and severity of IPVD and HPS.

METHODS

Consecutive adult patients with cryptogenic cirrhosis were evaluated for IPVD (by contrast echocardiography) and for hypoxemia (by arterial blood gas analysis). Plasma H₂S and nitrate levels were measured in these patients.

RESULTS

Fifty-eight patients with cryptogenic cirrhosis (male, 45; median age, range, 45, 16-74 years; Child's class; A, 30; B, 18; C, 10) were enrolled in this study. Thirty-four of the 58 (59%) patients had IPVD and 13 (22%) had HPS (mild, 4; moderate, 5; severe, 2; very severe, 2). Plasma H₂S levels were significantly higher in patients with IPVD (19.6, 5.7-83 μmol/L) as compared to patients who had no IPVD (12.3, 0-47 μmol/L; p-value 0.03) with an area under receiver operating characteristic curve of 0.68 (95% CI 0.53-0.84). Plasma H₂S levels were higher in patients with IPVD irrespective of liver disease severity. There was a trend for higher plasma nitrate levels in patients with IPVD (47, 15.8-126.4 nmol/mL) as compared to patients who had no IPVD (32.3, 6.9-51.4 nmol/mL; p-value 0.1). Raised plasma H₂S and nitrate levels had an additive effect on the presence of IPVD. Neither plasma H₂S nor plasma nitrate levels correlated with the degree of hypoxemia.

CONCLUSION

Raised plasma H₂S and nitrate levels predict the presence of IPVD in patients with cryptogenic cirrhosis.

Portal hypertension and its management in children

Portal hypertension (PHT), defined as raised intravascular pressure in the portal system, is a complication of chronic liver disease or liver vascular occlusion. Advances in our ability to diagnose and monitor the condition but also predict the risk of gastrointestinal bleeding have enabled us to optimise the management of children with PHT either at a surveillance or at a postbleeding stage. A consensus among paediatric centres in the classification of varices can be beneficial in streamlining future paediatric studies. New invasive (endoscopic and surgical procedures) and non-invasive (pharmacotherapy) techniques are currently used enabling clinicians to reduce mortality and morbidity in children with PHT.

Persistent Unexplained Dyspnea: A Case of Hepatopulmonary Syndrome

Regarding a patient with dyspnea, the history and physical examination often lead to the correct diagnosis. In some circumstances, when more than one underlying disease is present, the diagnostic process can be more challenging. We describe an unusual case of dyspnea and persistent hypoxemia related to a hepatopulmonary syndrome in a 53-year-old patient with known heart failure and chronic liver disease. Initially managed with intravenous diuretic therapy, due to signs of lung and peripheral congestion, our patient did not improve as expected; therefore we performed more advanced studies with a chest-abdomen CT scan and a right heart catheterization. They showed, respectively, no signs of parenchymal and vasculature lung disease, a cirrhotic liver disease, splenomegaly, signs of portal hypertension, and high cardiac output with normal pulmonary vascular resistance. These results, along with the association of hypoxemia and chronic liver disease, suggested a hepatopulmonary syndrome. The diagnosis was confirmed by the demonstration of an intrapulmonary vascular dilatation with right to left shunt during a microbubble transthoracic echocardiography and a lung perfusion scan. Liver transplantation is the only successful treatment for this syndrome; however, the patient became soon unsuitable for this strategy, due to a rapid clinical deterioration.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Implications for Liver Transplantation

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PoPH) represent serious pulmonary complications of advanced liver diseases. Orthotopic liver transplantation (OLT) is capable of completely resolving the underlying abnormalities associated with HPS. On the other hand, post-OLT response in patients with PoPH is less predictable, although heavily influenced by pre-OLT mean pulmonary arterial pressure. It remains the case that the opportunity to reverse 2 potentially fatal organ dysfunctions in the liver and the lung make HPS and PoPH more than worthy for further clinical investigations.

Anesthesia for Patients with Concomitant Hepatic and Pulmonary Dysfunction

Hepatic function and pulmonary function are interrelated with failure of one organ system affecting the other. With improved therapies, patients with concomitant hepatic and pulmonary failure increasingly enjoy a good quality of life and life expectancy. Therefore, the prevalence of such patients is increasing with more presenting for both emergent and elective surgical procedures. Hypoxemia requires a thorough evaluation in patients with end-stage liver disease. The most common etiologies respond to appropriate therapy. Portopulmonary hypertension and hepatopulmonary syndrome are associated with increased perioperative morbidity and mortality. It is incumbent on the anesthesiologist to understand the physiology of liver failure and its early effect on pulmonary function to ensure a successful outcome.

Emerging hepatic syndromes: pathophysiology, diagnosis and treatment

Liver cirrhosis is a major cause of morbidity and mortality worldwide, mainly due to complications of portal hypertension. In this article, we review the current understanding on the pathophysiology, the diagnostic criteria and the available therapeutic options for patients with emerging hepatic syndromes in cirrhosis, namely the hepatorenal, hepato-adrenal and hepatopulmonary syndrome. The hepatorenal syndrome is a well-recognized complication of advanced cirrhosis and is usually associated with an accelerated course to death unless liver transplantation is performed. The hepatopulmonary syndrome is often missed in the evaluation of patients with cirrhosis; however, early recognition is essential for the efficient management of individual patients. The hepato-adrenal syndrome, although not fully characterized, offers an exciting field for research and potential therapeutic interventions.

Systemic hemodynamics in advanced cirrhosis: Concerns during perioperative period of liver transplantation

Advanced liver cirrhosis is usually accompanied by portal hypertension. Long-term portal hypertension results in various vascular alterations. The systemic hemodynamic state in patients with cirrhosis is termed a hyperdynamic state. This peculiar hemodynamic state is characterized by an expanded blood volume, high cardiac output, and low total peripheral resistance. Vascular alterations do not disappear even long after liver transplantation (LT), and recipients with cirrhosis exhibit a persistent systemic hyperdynamic state even after LT. Stability of optimal systemic hemodynamics is indispensable for adequate portal venous flow (PVF) and successful LT, and reliable parameters for optimal systemic hemodynamics and adequate PVF are required. Even a subtle disorder in systemic hemodynamics is precisely indicated by the balance between cardiac output and blood volume. The indocyanine green (ICG) kinetics reflect the patient’s functional hepatocytes and effective PVF, and PVF is a major determinant of the ICG elimination constant (kICG) in the well-preserved allograft. The kICG value is useful to set the optimal PVF during living-donor LT and to evaluate adequate PVF after LT. Perioperative management has a large influence on the postoperative course and outcome; therefore, key points and unexpected pitfalls for intensive management are herein summarized. Transplant physicians should fully understand the peculiar systemic hemodynamic behavior in LT recipients with cirrhosis and recognize the critical importance of PVF after LT.

Evaluation of Arteriovenous Shunting in Patients With End-Stage Liver Disease: Potential Role of Early Right Heart Catheterization

BACKGROUND

In patients with end-stage liver disease (ESLD), the presence of hypoxemia suggests the presence of intrapulmonary oxygen shunting (IPS) and/or transatrial shunting. Early identification of each is imperative to avoid potentially fatal peritransplantation complications and appropriately prioritize patients for liver transplantation (LT). The aim of this work was to compare the sensitivity of transthoracic echocardiography (TTE) and right heart catheterization (RHC) with intracardiac echocardiography (ICE) for identifying the etiologies of resting hypoxemia in patients with ESLD being evaluated for LT.

METHODS

Records of 28 patients with ESLD and resting hypoxemia who underwent TTE with bubble study and RHC/ICE were reviewed. Patients with a patent foramen ovale (PFO) were compared with non-PFO patients to determine diagnostic accuracy of TTE with bubble study versus RHC/ICE.

RESULTS

TTE with bubble study diagnosed PFO, IPS, and pulmonary hypertension (PH), respectively, with sensitivities of 46%, 41%, and 25% and specificities of 46%, 45%, and 80% compared with RHC/ICE. Although IPS detected by RHC/ICE was more common in patients without a PFO (92%), 5 patients with a PFO (33%) also had IPS (P = .002). Isolated PH was detected exclusively in patients with a PFO (5/15; 33%).

CONCLUSIONS

TTE with bubble study is neither sensitive nor specific to exclude a PFO in patients with ESLD. RHC/ICE is a safe and accurate diagnostic/interventional modality in this group of patients and is useful to diagnose other comorbidities, such as IPS and PH, that may coexist and contribute to resting hypoxemia.

Hepatopulmonary syndrome: What we know and what we would like to know

Hepatopulmonary syndrome (HPS) is characterized by abnormalities in blood oxygenation caused by the presence of intrapulmonary vascular dilations (IPVD) in the context of liver disease, generally at a cirrhotic stage. Knowledge about the subject is still only partial. The majority of the information about the etiopathogenesis of HPS has been obtained through experiments on animals. Reported prevalence in patients who are candidates for a liver transplantation (LT) varies between 4% and 32%, with a predominance of mild or moderate cases. Although it is generally asymptomatic it does have an impact on their quality of life and survival. The diagnosis requires taking an arterial blood gas sample of a seated patient with alveolar-arterial oxygen gradient (AaO₂) ≥ 15 mm Hg, or ≥ 20 mm Hg in those over 64 years of age. The IPVD are identified through a transthoracic contrast echocardiography or a macroaggregated albumin lung perfusion scan (^99mTc-MAA). There is currently no effective medical treatment. LT has been shown to reverse the syndrome and improve survival rates, even in severe cases. Therefore the policy of prioritizing LT would appear to increase survival rates. This paper takes a critical and clinical look at the current understanding of HPS, as well as the controversies surrounding it and possible future research.

Portopulmonary hypertension

Portopulmonary hypertension (PoPH) refers to the condition that pulmonary arterial hypertension (PAH) occur in the stetting of portal hypertension. The development of PoPH is thought to be independent of the severity of portal hypertension or the etiology or severity of liver disease. PoPH results from excessive vasoconstriction, vascular remodeling, and proliferative and thrombotic events within the pulmonary circulation that lead to progressive right ventricular failure and ultimately to death. Untreated PoPH is associated with a poor prognosis. As PoPH is frequently asymptomatic or symptoms are generally non-specific, patients should be actively screened for the presence of PoPH. Two-dimensional transthoracic echocardiography is a useful non-invasive screening tool, but a definitive diagnosis requires invasive hemodynamic confirmation by right heart catheterization. Despite a dearth of randomized, prospective data, an ever-expanding clinical experience shows that patients with PoPH benefit from therapy with PAH-specific medications including with endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and/or prostanoids. Due to high perioperative mortality, transplantation should be avoided in those patients who have severe PoPH that is refractory to medical therapy.

[Hepatopulmonary syndrome]

Hepatopulmonary syndrome (HPS) is defined by the association of portal hypertension, increased alveolar-arterial oxygen gradient and intrapulmonary vascular dilations. Pathophysiological mechanisms of hypoxemia are characterized by ventilation-perfusion mismatch, oxygen diffusion limitation between alveolus and the centre of the dilated capillary, and right-to-left shunting. An excess of vasodilator molecules (like nitric monoxide) and proangiogenic factors (like VEGF) play an important role in the occurrence of HPS. Symptoms of HPS are not specific and dominated by a progressive dyspnea in upright position. Pulse oximetry is a simple non-invasive screening test but only detect the most severe forms of HPS. Medical treatment is disappointing and only liver transplantation may lead to resolution of HPS. Survival following liver transplantation is promising when hypoxemia is not severely decreased.

[Anesthesia with liver failure]

Liver failure can be categorized into acute liver failure, chronic liver failure and acute decompensation of chronic liver failure, the so-called acute-on-chronic liver failure, the incidence of which has increased over the last few years. Liver failure leads to a variety of pathophysiological changes where the extent is dependent on the nature and duration of the liver disease. This includes restriction of synthesis and metabolism, such as coagulation defects. Especially chronic liver failure is associated with malfunction of extrahepatic organs, such as the cardiovascular system, the respiratory system and the kidneys. In addition to these pathophysiological alterations the Child-Turcotte-Pugh classification (CTP) and the model of end stage liver disease (MELD) are used for perioperative risk stratification.