Portopulmonary hypertension: a tale of two circulations

Pulmonary hypertension after liver transplantation: case presentation and review of the literature

Hepatopulmonary syndrome and portopulmonary hypertension are the most common pulmonary vascular complications in patients with cirrhosis. Usually but not universally mutually exclusive, they each may present prior to liver transplantation and, if severe enough, may be a contraindication to transplant. However, there have been a number of case reports describing patients developing pulmonary hypertension de novo after liver transplantation. This report describes one such patient from our institution and reviews the medical literature describing this unusual clinical entity.

Pulmonary manifestations of liver diseases

Respiratory problems are common in patients with chronic liver diseases. The most common causes are disorders that are not related to liver diseases such as asthma and COPD. In addition certain liver diseases that are associated with specific pulmonary abnormalities, and conditions associated with end stage liver disease like tense ascites and intercostal muscular wasting are considered. Finally two unique disorders characterizing by vascular abnormalities independent of cardiorespiratory disorder-the hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are observed. These disorders have different pathogenesis, different clinical pictures, treatment and prognosis. This article reviews the epidemiology, pathophysiology, clinical features, evaluation and current therapy of these two disorders.

Portopulmonary hypertension associated with congenital absence of the portal vein treated with bosentan

Portopulmonary hypertension (PPHTN) is pulmonary arterial hypertension (PAH) associated with portal hypertension. It is a common condition among liver transplantation candidates; however, its association with congenital absence of the portal vein (CAPV) has not yet been established. CAPV is a very rare developmental anomaly, which is usually accompanied by abnormal mesenteric drainage that bypasses the liver. Here, we report a rare case of severe PPHTN secondary to CAPV.

Liver transplantation for pulmonary vascular complications of pediatric end-stage liver disease

PURPOSE

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPH) are poorly understood pulmonary complications of end-stage liver disease (ESLD). We present a case series of children with HPS and PPH.

METHODS

After institutional review board approval, query of our medical database identified children 0 to 18 years of age with ESLD diagnosed with HPS or PPH. Data were collected via chart review.

RESULTS

We identified 7 children with either HPS (n = 5) or PPH (n = 2). Patients with HPS presented with progressive dyspnea over a mean of 7 months (range, 4-12 months) at a mean of 13 years (range, 5-17 years) of age. Pulmonary shunting by albumin perfusion scan averaged 41% (range, 20%-66%) with an initial mean resting SpO(2) of 88% (range, 84%-94%) and mean SpO(2) during exertion of 79% (range, 60%-89%). Four patients required supplemental O(2) and, upon United Network for Organ Sharing (UNOS) appeal, received pediatric model for ESLD (or Child-Pugh) score exceptions, enabling them to undergo orthotopic liver transplant (OLT) within 1-2 months. The fifth patient was initially rejected by the UNOS regional review board, but 6 months of worsening hypoxemia led to OLT 2 months after successful UNOS appeal. All patients with HPS undergoing OLT experienced complete resolution of hypoxemia within 8 months. Both children with PPH were treated with intravenous epoprostenol, which lowered or stabilized mean pulmonary artery pressure and bridged them to OLT within 7 months of listing. Overall, there were no pulmonary complications; however, 1 patient with PPH expired shortly after OLT. The remaining patients are alive at a median follow-up of 27 months (range, 6-96 months).

CONCLUSION

Hepatopulmonary syndrome and PPH are uncommon complications of ESLD in children. Epoprostenol can bridge PPH patients to OLT. OLT leads to rapid resolution of HPS and PPH and currently represents the only successful treatment for these children.

Pulmonary arterial hypertension from a pediatric perspective

This review of pediatric pulmonary arterial hypertension provides a framework within which to view pulmonary hypertension in children. Classification schemes, including the latest recommendations from the World Health Organization, are discussed, and the histopathology of severe pulmonary hypertension is reviewed. New information is provided regarding idiopathic and familial forms of the disease. Specific childhood etiologies, including persistent pulmonary hypertension of the newborn and congenital heart disease, are reviewed. Additionally, we examine the role of collagen vascular diseases, portal hypertension, and viruses in the pathogenesis of severe pulmonary arterial hypertension.

Significant improvement of portopulmonary hypertension after 1-week terlipressin treatment

Cirrhosis associated with moderate and severe portopulmonary hypertension carries a poor prognosis. Optimal management has not yet been defined. Current treatment options, such as prostacyclin analogues, endothelin antagonists, and phosphodiesterase-5 inhibitors, are characterized by slow onset of action and various adverse effects, particularly in patients with advanced cirrhosis. Here, we report the significant reduction of pulmonary arterial pressure after 1-week terlipressin treatment in a patient with concomitant hepato-renal syndrome. Terlipressin could be a novel and safe treatment for portopulmonary hypertension.

Safety and efficacy of combined use of sildenafil, bosentan, and iloprost before and after liver transplantation in severe portopulmonary hypertension

Portopulmonary hypertension (PPHTN) represents a constrictive pulmonary vasculopathy in patients with portal hypertension. Liver transplantation (LT) may be curative and is usually restricted to patients with mild-to-moderate disease severity characterized by a mean pulmonary artery pressure (mPAP < 35 mm Hg). Patients with severe disease (mPAP > 50 mm Hg) are usually excluded from transplantation. We describe a patient with severe PPHTN, initiated on sequential and ultimately combination therapy of prostacyclin, sildenafil, and bosentan (PSB) pretransplantation and continued for 2 years posttransplantation. Peak mPAP on PSB therapy was dramatically reduced from 70 mm Hg to 32 mm Hg pretransplantation, and continued therapy facilitated a further fall in mPAP to 28 mm Hg posttransplantation. The pulmonary vascular resistance index fell from 604 to 291 dyne second(-1) cm(-5). The perioperative mPAP rose to 100 mm Hg following an episode of sepsis and fell with optimization of PSB therapy. In conclusion, this is the first reported patient with severe PPHTN using this combination of vasodilator therapy as a bridge to LT and then as maintenance in the posttransplantation phase. This regimen may enable LT in similar patients in the future, without long-term consequences.

Pulmonary Vascular Disease

The pulmonary vasculature is an anatomic compartment that is frequently overlooked in the histologic review of lung biopsy samples, other than those obtained specifically to assess pulmonary vascular disease.1 Though often of a nonspecific nature, the histologic pattern of vascular remodeling may at times suggest its underlying pathogenesis and provide clues to the cause of pulmonary hypertension.2 Disproportionately severe vascular pathology may further indicate alternate disease processes, such as congestive heart failure or thromboemboli, contributing to the patient’s overall respiratory condition.

Portopulmonary hypertension

As a result of the success of orthotopic liver transplantation, there has been increasing interest in the diagnosis and therapeutic options for the pulmonary vascular complications of hepatic disease. These pulmonary vascular complications range from the hepatopulmonary syndrome, which is characterized by intrapulmonary vascular dilatations, to portopulmonary hypertension (POPH), which is characterized by an elevated pulmonary vascular resistance as a consequence of obstruction to pulmonary arterial blood flow. This review concentrates on POPH.

Hepatopulmonary syndrome and portopulmonary hypertension

The incidence of pulmonary vascular disorders is significantly increased in patients with liver disease. Intrapulmonary shunting with hypoxemia in patients with liver disease is diagnosed as hepatopulmonary syndrome (HPS), whereas precapillary pulmonary vessel obliteration is identified as portopulmonary hypertension (PPHTN). Because the symptoms of liver disease can mimic those of pulmonary vascular disease, all patients with hepatic failure should be screened for these two diseases. Pulse oximetry effectively screens for hypoxemia associated with HPS, whereas an elevated right ventricular systolic pressure estimated by echocardiography identifies patients at risk of having PPHTN. Liver transplantation is the only effective medical therapy for HPS. However, those who have a resting arterial oxygenation less than 50 mm Hg or a shunt measured by scintigraphic perfusion greater than 20% have an unacceptably high mortality rate following surgery. Compared with HPS, there are more therapeutic options that can bridge patients with PPHTN to transplantation. Drugs used to manage idiopathic pulmonary hypertension have shown promise in the treatment of PPHTN. Prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors have improved transplant survival. Despite treatment, however, perioperative mortality for patients with PPHTN remains high. Even with successful transplantation, HPS and PPHTN can persist or develop de novo. Long-term follow-up and surveillance of liver transplant recipients is thus indicated to identify HPS and PPHTN following surgery.

The Noninvasive Evaluation of Exercise-induced Changes in Pulmonary Artery Pressure and Pulmonary Vascular Resistance

BACKGROUND

During exercise, pulmonary artery systolic pressure (PASP) may increase. The purpose of this study was to examine the responses of PASP and pulmonary vascular resistance by Doppler echocardiography during exercise in conditioned athletes and in patients with pulmonary disease.

METHODS

Fifteen participants in each group were evaluated using Doppler echocardiography at rest and during recumbent bicycle exercise. PASP was calculated using 4 times the tricuspid regurgitant velocity squared (TRV)2 and a surrogate for pulmonary vascular resistance was calculated using the equation: pulmonary vascular resistance = TRV/right ventricular outflow tract time-velocity integral.

RESULTS

During exercise, PASP increased in both groups with higher values achieved by patients with pulmonary conditions (54.8 vs 70.6 mm Hg, P = .009). At baseline the ratio TRV/right ventricular outflow tract time-velocity integral was 0.2 or less in both the athlete and pulmonary groups. During exercise, the ratio of TRV/right ventricular outflow tract time-velocity integral remained less than 0.2 in the athletes and increased more than 0.2 in the pulmonary group.

CONCLUSION

Doppler echocardiography can be used to discriminate a flow- versus resistance-mediated mechanism for exercised-induced increase in PASP.

Hypertension portopulmonaire

INTRODUCTION

Porto-pulmonary hypertension (PoPH) is the association of pulmonary artery hypertension and portal hypertension. The diagnosis of PoPH is based on pulmonary haemodynamic criteria, obtained via right heart catheterisation, including an increase in mean pulmonary arterial pressure (> 25 mmHg) and in pulmonary vascular resistance (> 240 dyn.s.cm-5).

STATE OF THE ART

The exact pathophysiological mechanisms of PoPH are unknown. However, since PoPH has been reported in patients with non-hepatic portal hypertension, the factor that determines the development must be portal hypertension rather than liver disease per se. Moreover, no simple relationship has been identified between the degree of hepatic impairment and the severity of PoPH. The clinical presentation is non-specific with haemodynamic failure occurring at the end stage. As a consequence, screening by annual transthoracic echocardiography is highly recommended in potential liver transplant candidates. Therapy with prostacyclin analogues may partially relieve pulmonary arterial hypertension (PAH). Liver transplantation has an uncertain effect in PoPH and because PoPH is associated with a high perioperative mortality, moderate to severe PoPH remains a contraindication for liver transplantation.

PERSPECTIVES AND CONCLUSIONS

Recent advances in the management of PoPH have improved the prognosis. The safety and efficacy of oral endothelin receptor antagonists and oral phosphodiesterase inhibitors is currently under evaluation. A therapeutic approach utilising combinations of drugs should provide better long-term results.

Clinical differences between idiopathic and scleroderma-related pulmonary hypertension

OBJECTIVE

Pulmonary arterial hypertension related to scleroderma (PAH-Scl) is associated with high morbidity and mortality as well as poorer response to therapy and worse outcomes compared with the idiopathic form of PAH (IPAH). Scleroderma is an autoimmune disease that can affect left and right heart function directly through inflammation and fibrosis and indirectly through systemic and pulmonary hypertension. This study tested the hypothesis that an increased prevalence of left heart disease might explain the higher mortality in patients with PAH-Scl compared with patients with IPAH.

METHODS

The study was designed as a retrospective cohort study comparing the baseline clinical data from 91 consecutive patients (41 with IPAH and 50 with PAH-Scl). Cox proportional hazards models were used to predict the effect of clinical covariates on patient survival.

RESULTS

Patients with PAH-Scl had a lower mean pulmonary artery pressure (46.6 mm Hg versus 54.4 mm Hg in patients with IPAH; P = 0.002) despite similar levels of cardiac dysfunction (cardiac index 2.2 and 2.1 liters/minute/m(2), respectively; P = 0.19). Echocardiography revealed similar degrees of right ventricular dysfunction in the 2 groups, whereas a predominance of left heart dysfunction was observed in patients with PAH-Scl. One- and three-year survival estimates were 87.8% and 48.9%, respectively, in patients with PAH-Scl and 95.1% and 83.6%, respectively, in those with IPAH. Patients with PAH-Scl were 3.06 times more likely to die than were patients with IPAH, after controlling for the presence of pericardial effusion; there was no significant change in increased risk of death in PAH-Scl after controlling for left heart disease.

CONCLUSION

The results confirm that there are significant clinical and survival differences between IPAH and PAH-Scl. The presence of left heart disease, although more common in PAH-Scl, was not predictive of the higher mortality in these patients.

Hepatopulmonary syndrome and right ventricular diastolic functions: an echocardiographic examination

AIM

Liver functions are affected in the course of cardiac diseases, and similarly, liver diseases affect cardiac functions. Many studies in the literature have shown that left ventricular systolic and/or diastolic dysfunction may develop during chronic liver disease. However, there are limited studies investigating right ventricular functions during chronic liver diseases.

METHODS

A total of 84 patients who had no systolic and/or diastolic dysfunction in the left ventricle (LV) were evaluated; 46 patients with liver cirrhosis; 10 (21.74%) cirrhotic patients with hepatopulmonary syndrome (HPS) (group 1), 36 (78.26) cirrhotic patients without HPS (group 2), and 38 healthy individuals were treated as control.

RESULTS

Right ventricular diastolic dysfunction was determined in all patients of group 1 (100%), 26 of group 2 (72.22 %), and 4 of the controls (10.52%) (P<0.05). Tricuspid deceleration time (dt) was significantly different between the groups (P<0.05). In addition, right atrium (RA) diameters, right ventricle (RV) diameters, and RV wall thickness were significantly different between the groups (P<0.05). Pulmonary artery pressure (P<0.05) and pulmonary vascular resistance (P<0.05) were also seen to be higher in group 1 than those in group 2 and control group.

CONCLUSIONS

Right ventricular diastolic dysfunction rate is high in chronic liver diseases. In the presence of HPS, right ventricular diastolic dysfunction is more remarkable in patients than those without HPS. Right ventricular diastolic dysfunction may result in dilatation and hypertrophy in the right heart.

Efficiency and safety of bosentan in child C cirrhosis with portopulmonary hypertension and renal insufficiency

Bosentan has lately been described as a successful therapeutic agent for portopulmonary hypertension consecutive to child A cirrhosis. This is the first report of the effect of this substance with advanced liver cirrhosis (child C) and renal insufficiency. Low doses of bosentan (initially twice 31.25 mg/day and then 62.5 mg/day) increased cardiac output and allowed correction of renal insufficiency; it allowed one to stop the requirement of oxygen and not only improved the 6-min walking test by more than 400 m, but also decreased the severity of the liver cirrhosis to child B stadium. This suggests that patients, who would be excluded from a liver transplantation program because of their portopulmonary hypertension, could profit from a careful therapy with bosentan.

Portopulmonary hypertension

Portopulmonary hypertension (PPHT) is defined as precapillary pulmonary hypertension accompanied by hepatic disease or portal hypertension. Pulmonary hypertension results from excessive pulmonary vascular remodeling and vasoconstriction. These histological alterations have been indistinguishable from those of other forms of pulmonary arterial hypertension. Factors involved in the pathogenesis of PPHT include volume overload, hyperdynamic circulation, and circulating vasoactive mediators. The disorder has a substantial impact on survival and requires focused treatment. Liver transplantation in patients with moderate to severe PPHT is associated with a significantly reduced survival rate. The best medical treatment for patients with PPHT is controversial; most authors currently regard continuous intravenous application of prostacyclin as the treatment of choice for patients with severe PPHT. There is only very limited reported experience with inhaled prostacyclin or its analog, iloprost. Increasing evidence of the efficacy of the endothelin-receptor antagonist bosentan and of the phosphodiesterase-5 inhibitor sildenafil is emerging in highly selected patients with PPHT. In the future, a combination therapy of the above-mentioned agents might become a therapeutic option. Other agents such as beta-blockers seem to be harmful to patients with moderate to severe portopulmonary hypertension. Up-to-date, randomized, double-blind, controlled clinical trials are lacking and are needed urgently.

Bosentan treatment of portopulmonary hypertension related to liver cirrhosis owing to hepatitis C

Pulmonary arterial hypertension (PAH) with coexisting portal hypertension has been defined as portopulmonary hypertension (PPHTN). It is often related to liver cirrhosis of various aetiologies and is associated with a high mortality rate. Endothelin-1 (ET) is supposed to play an important role in the pathogenesis of PAH as well as portal hypertension. Therefore, therapy with an ET(A)/ET(B) receptor antagonist might be of use in the treatment of PPHTN. We report the case of a 76-year-old male with liver cirrhosis owing to chronic hepatitis C virus infection and PPHTN who was treated with the dual ET(A)/ET(B) receptor antagonist bosentan. The patient showed remarkable improvement of 6-min walking distance from 300 to 480 m after 2 weeks and to 540 m after 14 weeks, respectively. In addition, a significant decline of N-terminal pro B-type natriuretic peptide fraction (NT-proBNP) from 4928 ng mL(-1) to 640 ng mL(-1) was observed. Bosentan might be a promising new therapeutical option for patients suffering from PPHTN.

Endothelin and endothelin receptor antagonism in portopulmonary hypertension

Portopulmonary hypertension (PPHT) is a rare but devastating complication in patients with portal hypertension, characterized by pulmonary arterial obliterative disease with a concomitant rise in pulmonary vascular resistance. A broad body of evidence has accumulated, indicating that endothelin (ET) peptides and their cognate receptors are causally involved in the pathophysiology of pulmonary arterial hypertension (PAH) owing to different aetiologies, including PPHT. In addition, the ET system may be involved in hepatic fibrotic remodelling and portal hypertension. Several experimental models have provided evidence that ET receptor antagonism may have therapeutic potential in PPHT. Initial experience has accumulated during the last 2 years, suggesting that targeting the ET system may have beneficial effects in the clinical setting. In these studies, the orally active, dual ET receptor antagonist bosentan improved pulmonary haemodynamics and functional capacity. These effects were sustained and occurred in the absence of adverse events. If these observations can be corroborated by controlled clinical trials, bosentan would offer several advantages over available therapies, which have major drawbacks owing to their invasive and demanding mode of application.

Portopulmonary hypertension

Portopulmonary hypertension is a common condition in patients who have portal hypertension. This article reviews the definition and clinical presentation of this disorder and outlines our current understanding of its pathophysiology. A diagnostic approach is provided , and novel medical therapies that are being investigated to treat this condition are discussed. Finally, the safety of liver transplantation in patients who have portopulmonary hypertension is reviewed.

Hepatopulmonary syndrome

The hepatopulmonary syndrome (HPS) is an important and often under-recognized vascular complication of cirrhosis and portal hypertension characterized by pulmonary vascular dilatation, which results in hypoxemia. This syndrome is identified in as many as 20% of patients who are evaluated for orthotopic liver transplantation (OLT), and it has recently been found to increase mortality in affected patients, particularly when hypoxemia is severe. Currently, OLT is the only therapy established to reverse intrapulmonary vasodilatation, although postoperative mortality is increased in patients with severe hypoxemia. No randomized controlled trials of pharmacologic therapies have been undertaken, but supplemental oxygen improves oxygenation. Data derived from case reports, small studies, and experimental models suggest that pharmacologic therapies may be effective. In cirrhotic patients with HPS, particularly those with moderate hypoxemia (PaO2 < 60 mmHg), OLT should be considered prior to the development of severe deoxygenation. Supplemental oxygen should be given to patients with a PaO2 < 60 mmHg or those with exercise oxygen desaturation. For those patients with mild hypoxemia or those who are not OLT candidates, a trial of pharmacologic treatment may be considered.

Development of pulmonary hypertension in 5 patients after pediatric living-donor liver transplantation: de novo or secondary?

The development of portopulmonary hypertension (PH) in a patient with end-stage liver disease is related to high cardiac output and hyperdynamic circulation. However, PH following liver transplantation is not fully understood. Of 617 pediatric patients receiving transplants between June 1990 and March 2004, 5 (median age 12 yr, median weight 24.5 kg) were revealed to have portopulmonary hypertension (PH) after living-donor liver transplantation (LDLT), as confirmed by echocardiography and/or right heart catheterization. All children underwent LDLT for post-Kasai biliary atresia. In 2 patients with refractory biliary complications, PH developed following portal thrombosis; 2 with stable graft function, who had had intrapulmonary shunting (IPS) before LDLT, were found to have PH in spite of overcoming liver dysfunction due to hepatitis. PH developed shortly after distal splenorenal shunting in 1 patient, who suffered liver cirrhosis due to an intractable outflow blockage. The onset of PH ranged from 2.8 to 11 yr after LDLT, and mean pulmonary artery pressure (mPAP) estimated by echocardiography at the time of presentation ranged from 43 to 120 mmHg. Three of the 5 patients are alive under prostaglandin I2 (PGI2) treatment. Of these, 1 is prepared for retransplantation for an intractable complications of liver allograft, while the other 2 with satisfactory grafts are being considered for lung transplantation. Even after LDLT, PH can develop with portal hypertension. Periodic echocardiography is essential for early detection and treatment of PH especially in the recipients with portal hypertension not only preoperatively but also postoperatively.

Pulmonary hypertension and right-sided heart failure in an adult llama with hepatic disease

CASE DESCRIPTION

A 13-year-old llama was examined because of lethargy, inappetence, and syncope.

CLINICAL FINDINGS

Physical examination revealed muffled heart and lung sounds and peripheral edema. Clinicopathologic abnormalities included lymphopenia, hyperglycemia, prerenal azotemia, mild hyponatremia, mild hypoalbuminemia, and high gamma-glutamyltransferase and creatine kinase activities. On ultrasonography, the liver appeared hyperechoic and ascites and pleural effusion were seen. Echocardiography revealed severe dilatation of the right atrium, right ventricle, and pulmonary artery; severe tricuspid regurgitation; and high right ventricular systolic pressure consistent with right-sided heart failure secondary to pulmonary hypertension.

TREATMENT AND OUTCOME

Treatment with furosemide was attempted, but because of failing health, the llama was euthanized 4 weeks later. Macronodular cirrhosis of the liver, glomerulonephritis, and intimal fibrosis and medial hypertrophy of muscular pulmonary arteries were seen on histologic examination of postmortem specimens.

CLINICAL RELEVANCE

Findings in this case were similar to those reported for human patients with portopulmonary hypertension secondary to hepatic cirrhosis. Pulmonary hypertension secondary to hepatic disease should be considered in the differential diagnosis of right-sided heart failure.

Liver transplantation in high-risk patients: hepatopulmonary syndrome and portopulmonary hypertension

Two pulmonary vascular disorders, considered mutually exclusive, may be present in candidates for orthotopic liver transplantation (OLT). On the one hand, hepatopulmonary syndrome (HPS), with a prevalence about 20% in end-stage liver disease, is characterized by pulmonary vascular dilatation and abnormal gas exchange. On the other hand, portopulmonary hypertension (POPH), a process defined by pulmonary hypertension associated with portal hypertension, is less common than HPS (4%). These entities have very distinct clinical implications; whereas HPS is clinically characterized by respiratory symptoms that evolve to severe hypoxemia, patients with POPH are commonly asymptomatic, frequently diagnosed in the setting of OLT, and the symptoms appear when there is hemodynamic compromise. The pathogenesis of both entities is a putative mechanism, the imbalance of vasoactive substances in pulmonary vessels. The role of OLT to reverse these vascular disorders is controversial, although complete resolution of HPS and, less frequently, POPH following OLT has been reported. The recognition that the presence of both HPS and POPH is an important cause of morbidity and mortality among recipients of OLT has resulted in a change in the policy to select OLT candidates. Accurate identification of patients with pulmonary vascular disorders associated with liver disease should be the first step in the management of OLT candidates. Because the determinants of the prognosis of OLT in the setting of these pulmonary vascular changes have not been well established, an accurate cardiopulmonary evaluation with careful assessment of pulmonary gas exchange (in HPS) and right ventricular function (in POPH) of potential OLT recipients is mandatory before the procedure.

Portopulmonary hypertension in childhood presenting as sudden death

We present the case of a 9-year-old boy with portal hypertension who died suddenly and unexpectedly due to pulmonary hypertensive crisis during a routine endoscopic procedure. He had known portal hypertension with esophageal varices but had no preceding clinical symptoms suggestive of significant pulmonary hypertensive disease despite postmortem histological evidence of advanced pulmonary vascular changes. Portopulmonary hypertension is a well-described and distinct clinical syndrome that is rare in childhood and is associated with a relatively poor prognosis. Occasional patients with histologically advanced disease may remain asymptomatic but present with pulmonary hypertensive crisis. Children with portopulmonary hypertension should be considered at high risk for surgical procedures, and pulmonary hypertensive complications should be excluded as a cause of death in all children dying suddenly in the setting of portal hypertension.

Hepatitis C virus and the lung: implications for therapy

Hepatitis C virus (HCV) infection is a chronic blood-borne disease that affects > 4,000,000 individuals in the United States. The majority of individuals with HVC infection acquire a chronic hepatitis that predisposes them to the complications of cirrhosis and hepatoma. Chronic HCV infection is, however, associated with multiple extrahepatic manifestations as well, including recently recognized effects on the lung. These include primary effects on lung function, as well as secondary effects in the settings of progressive liver disease and drug treatment for HCV. In this article, we discuss the emerging clinical data that support a role for HCV infection in lung disease, describe the multiple pulmonary manifestations of this viral infection, and outline the therapies available for specific pulmonary complications of chronic HCV infection.

Hepatopulmonary syndrome

The hepatopulmonary syndrome is an increasingly important vascular complication of cirrhosis where microvascular dilatation impairs arterial oxygenation in the setting of liver disease. This syndrome is identified in as many as 20% of patients evaluated for liver transplantation and results in increased mortality. No clearly effective medical therapies are available, and liver transplantation is the only established treatment. Pathophysiologic insights obtained from experimental models may lead to the development of novel and effective medical treatments.

Portopulmonary hypertension in pediatric patients

OBJECTIVES

To investigate the clinical presentation, manifestations, and response to therapy of portopulmonary hypertension (PPHTN) in pediatric patients.

STUDY DESIGN

This study was a retrospective chart review describing the evaluation and course of 7 patients with PPHTN.

RESULTS

Causes of portal hypertension (HTN) included biliary atresia (3 cases), cavernous transformation of the portal vein (2 cases), and primary sclerosing cholangitis and cryptogenic cirrhosis (1 case each). The median interval from the diagnosis of portal HTN to PPHTN was 12.1 years. Four patients presented with a new heart murmur, 4 presented with syncope, and 3 presented with dyspnea. Although electrocardiograms (ECGs) and chest x-rays were normal in 3 and 2 patients, respectively, echocardiograms diagnosed pulmonary HTN in all 7 patients. Five patients had cardiac catheterizations; the average mean pulmonary artery pressure was 65 +/- 20 mm Hg. Response to therapy was variable, and 4 patients died. Postmortem lung tissue examination revealed plexiform lesions and pulmonary arteriopathy.

CONCLUSIONS

Because symptoms are subtle and may be overlooked, pediatric patients with portal HTN who develop a new heart murmur, dyspnea, syncope, or who are being evaluated for liver transplantation require evaluation for PPHTN. ECG and chest x-ray are insensitive screens for PPHTN. An echocardiogram and cardiology evaluation is essential for the diagnosis.

Use of a mixed endothelin receptor antagonist in portopulmonary hypertension: a safe and effective therapy?

BACKGROUND & AIMS

Portopulmonary hypertension (PPHTN), a severe complication of portal hypertension is observed in 3%-6% of patients evaluated for liver transplantation. Endothelin-1, a potent vasoconstrictor, is likely to play a role in the pathogenesis of primary pulmonary hypertension, and, in 2 recent trials, the dual endothelin receptor antagonist bosentan has shown beneficial effects in this disease. A role for endothelins in the development of both pulmonary hypertension and cirrhosis has been suggested. We therefore hypothesized that endothelin receptor blockade may be beneficial in the treatment of PPHTN.

METHODS

We report a case of a 42-year-old patient with PPHTN and alcoholic cirrhosis treated with the mixed endothelin receptor antagonist bosentan.

RESULTS

The patient rapidly improved from NYHA IV to stage II, experienced a remarkable improvement of 6-minute walking distance from 0 to 590 m within 6 months, and resumed working full-time as a locksmith after 7 months of treatment. Improvement of cardiovascular parameters included a reduction of pulmonary vascular resistance by 60%, a decrease of mean pulmonary artery pressure (mPAP) from 55 to 44 mm Hg at 9 months, and a decline of plasma B-type natriuretic peptide (BNP) from 339 pg/mL to 19 pg/mL after 1 year. There were no adverse events except for a transient decrease in systemic blood pressure.

CONCLUSIONS

To our knowledge, this is the first report of a patient with PPHTN treated with an endothelin receptor antagonist. The marked and sustained improvement supports the undertaking of controlled studies of the safety and efficacy of bosentan in PPHTN.

Association of Limited Scleroderma and Pulmonary Hypertension in a Patient with Primary Biliary Cirrhosis

We report a male patient with primary biliary cirrhosis (PBC) who developed limited scleroderma (l-SSc) and pulmonary hypertension (PHT). He had noticed shortness of breath seven months earlier, which slowly progressed before admission. Sclerodactyly and telagiectasia of the fingers and chest wall were found. Chest X-ray and Doppler echocardiography suggested the presence of PHT. Histologic examination of the liver (needle biopsy) revealed stage two PBC, and histologic findings of the skin (obtained from the dorsum of right finger IV) were compatible with l-SSc. Direct measurement of pulmonary arterial pressure revealed PHT with normal capillary wedge pressure during right heart catheterization. A striking increment of plasma thromboxane B(2) across the lungs was found, which suggested that thromboxane A(2) (precursor of thromboxane B(2)) contributed considerably to a rise in pulmonary vascular resistance leading to PHT.

The biological "scrabble" of pulmonary arteriovenous malformations: considerations in the setting of cavopulmonary surgery

Pulmonary arteriovenous fistulas are vascular malformations, which, by virtue of producing abnormal vascular connections proximal to the units of gas exchange, result in intrapulmonary right-to-left shunting. These malformations or fistulas reflect at least in part disordered angiogenesis, and less commonly recruitment and dilation of pre-existing vascular channels. Pulmonary arteriovenous fistulas occur in a number of diverse clinical settings. Such fistulas are a well-established feature of the Weber-Osler-Rendu complex, or hereditary haemorrhagic telangiectasia, an autosomal dominant vascular dysplasia characterized by mucocutaneous telangiectasis, epistaxis, gastrointestinal haemorrhage, and arteriovenous malformations in the lung, brain, liver and elsewhere. They are also seen in the patient with acute or chronic liver disease, disease that is usually but not invariably severe, or those with non-cirrhotic portal hypertension. They may occur as congenital malformations, single or diffuse, large or small in isolation, and when large or extensive enough may result in hypoxaemia, clinical cyanosis, and heart failure. Cerebral vascular accidents are also a well-known complication of this disorder. An extensive literature has accumulated with regard to the pulmonary arteriovenous fistulas seen in the setting of the Weber-Osler-Rendu complex, and there is considerable information on the genetics, basic biology, clinical findings, complications and therapeutic interventions of these malformations in the setting of this syndrome. These issues, however, are not the primary considerations of this review, although some aspects of this fascinating disorder will be discussed later. Rather the focus will be on pulmonary arteriovenous malformations that develop in the setting of cavopulmonary surgery, and their relationship to the pulmonary arteriovenous fistulas occurring in the hepatopulmonary syndrome. The complex tapestry of these overlapping and intersecting clinical observations will be unfolded in the light of their chronology.

Effects of terlipressin on systolic pulmonary artery pressure of patients with liver cirrhosis: An echocardiographic assessment

AIM: Portopulmonary hypertension is a serious complication of chronic liver disease. Our aim was to search into the effect of terlipressin on systolic pulmonary artery pressure among cirrhotic patients.

METHODS: Twelve patients (6 males and 6 females) with liver cirrhosis were recruited in the study. Arterial blood gas samples were obtained in sitting position at rest. Contrast enhanced echocardiography and measurements of systolic pulmonary artery pressure were performed before and after the intravenous injection of 2 mg terlipressin.

RESULTS: Of 12 patients studied, the contrast enhanced echocardiography was positive in 5, and the positive findings in contrast enhanced echocardiography were reversed to normal in two after terlipressin injection. The mean systolic pulmonary artery pressure was 25.5 ± 3.6 mmHg before terlipressin injection, and was 22.5 ± 2.5 mmHg after terlipressin (P = 0.003). The systolic pulmonary artery pressure was above 25 mmHg in seven of these 12 patients. After the terlipressin injection, systolic pulmonary artery pressure was < 25 mmHg in four of these cases (58.3% vs 25%, P = 0.04).

CONCLUSION: Terlipressin can decrease the systolic pulmonary artery pressure in patients with liver cirrhosis.

Portopulmonary hypertension and hepatopulmonary syndrome

The clinically and pathophysiologically distinct entities of portopulmonary hypertension and hepatopulmonary syndrome occur in a substantial proportion of patients who have advanced liver disease of different causes. These disorders are notoriously underdiagnosed, but they have a substantial impact on survival and require focused treatment. Abnormal intrapulmonary vascular dilatation, the hallmark of hepatopulmonary syndrome, can cause profound hypoxaemia that can be very difficult to treat. By contrast, portopulmonary hypertension results from excessive pulmonary vasoconstriction and vascular remodelling that eventually leads to right-heart failure. Insights into the pathogeneses of these syndromes have led to novel therapeutic approaches. However, in severely affected patients, effective treatment remains a difficult task. In selected patients, liver transplantation represents the only treatment option, but the decision to do isolated liver transplantation is particularly challenging in patients who have severe pulmonary disease involvement. Data from several centres have contributed to provide criteria that allow improved prediction of which patients may, or may not, benefit from liver transplantation alone.

Hepatopulmonary syndrome: a concern for the anesthetist? Pre-operative evaluation of hypoxemic patients with liver disease

Liver cirrhosis and other chronic hepatic diseases are followed in a subset of affected patients by gas exchange abnormalities resulting from a syndrome called hepatopulmonary syndrome (HPS). The structural basis of this clinical entity is an alteration of pulmonary vasculature resulting in abnormal vasodilatation and mismatching of ventilation and perfusion of the lung. Dilatation of the capillary bed near the gas exchange area is the most important factor implicated; it precludes O2 molecules diffusing to the centrum of the dilated vessels to oxygenate venous blood. Contrast (microbubbles) echocardiography and lung perfusion scan are, respectively, the screening tests with the highest sensitivity and specificity for HPS diagnosis. Because of the high morbidity and mortality of HPS, clinicians have been trying to understand the pathophysiology of pulmonary vasodilatation in the hope that the process can be reversed pharmacologically or surgically. An imbalance between production and clearance of vasoactive circulating substances has been implicated in the pathogenesis of HPS with glucagon and nitric oxide among the principal responsible factors. To date various molecules have been implicated for therapy but without definitive positive results. Liver transplantation remains the only real therapy for HPS, and resolution of gas exchange defects outlines the possible functional reversible nature of vascular abnormalities of this syndrome. The need to perform surgery under general anesthesia for hepatic and extrahepatic procedures in patients with HPS is followed by an increased peri-operative risk. The authors emphasize the role of pre-operative clinical evaluation for proper patient management during the peri-operative period.