Hepatopulmonary syndrome in inferior vena cava obstruction responding to cavoplasty

Left Ventricular Dilation and Pulmonary Vasodilatation after Surgical Shunt for Treatment of Pre-Sinusoidal Portal Hypertension

Objective

The aim of this study was to prospectively investigate the long-term cardiovascular and pulmonary hemodynamic effects of surgical shunt for treatment of portal hypertension (PH) due to Schistosomiasis mansoni.

Location

The University of São Paulo Medical School, Brazil; Public Practice.

Methods

Hemodynamic evaluation was performed with transesophageal Doppler and contrast-enhanced echocardiography (ECHO) on twenty-eight participants with schistosomal portal hypertension. Participants were divided into two groups according to the surgical procedure used to treat their schistosomal portal hypertension within the last two years: group 1—distal splenorenal shunt (DSRS, n = 13) and group 2—esophagogastric devascularization and splenectomy (EGDS, n = 15).

Results

The cardiac output (5.08 ± 0.91 L/min) and systolic volume (60.1 ± 5.6 ml) were increased (p = 0.001) in the DSRS group. DSRS participants had a significant increase (p < 0.0001) in their left ventricular end-systolic and end-diastolic diameters as well as in their left ventricular end-diastolic and end-systolic volumes (p < 0.001) compared with the preoperative period. No statistically significant difference was found in the patients who underwent EGDS. ECHO revealed intrapulmonary vasodilatation (IPV) in 18 participants (64%), 9 DSRS and 9 EGDS (p > 0.05).

Conclusions

The late increase in the cardiac output, stroke volume and left ventricular diameters demonstrated left ventricular dilatation after a distal splenorenal shunt. ECHO revealed a greater prevalence for IPV in patients with schistosomiasis than has previously been described in patients with PH from liver cirrhosis.

Hepatopulmonary Syndrome and Liver Transplantation: A Recent Review of the Literature

A severe and common pulmonary vascular complication of liver disease is hepatopulmonary syndrome (HPS). It is a triad of liver dysfunction and/or portal hypertension, intrapulmonary vascular dilatations, and increased alveolar-arterial oxygen gradient. Prevalence varies according to various study groups from 4%-47%. While the most common presenting symptom of HPS is dyspnea, it is usually asymptomatic, and thus all liver transplant candidates should be screened for its presence. Pulse oximetry is a useful screening method, but arterial blood gas examination is the gold standard. If there is an abnormal P (A-a)O2 gradient, microbubble transthoracic echocardiography should be done for diagnosis. Outcome is unpredictable, and there is currently no effective medical therapy. The only effective therapy is considered to be liver transplantation. Complete resolution of HPS after liver transplantation is seen within a year in most HPS patients.

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

Hepatopulmonary syndrome and portopulmonary hypertension are cardiopulmonary complications, which are not infrequently seen in patients with liver disease and/or portal hypertension. These entities are both clinically and pathophysiologically different: the hepatopulmonary syndrome is characterized by abnormal pulmonary vasodilation and right-to-left shunting resulting in gas exchange abnormalities, whereas portopulmonary hypertension is caused by pulmonary artery vasoconstriction leading to hemodynamic failure. As both hepatopulmonary syndrome and portopulmonary hypertension are associated with significantly increased morbidity and mortality, and as these patients are commonly asymptomatic, all liver transplantation candidates should be actively screened for the presence of these two complications. The aim of is this review is to provide an overview on the hepatopulmonary syndrome and portopulmonary hypertension with primary focus on diagnosis and recent knowledge regarding pathogenesis and therapeutic targets.

Hepatopulmonary syndrome: update on pathogenesis and clinical features

Hepatopulmonary syndrome (HPS) is a serious vascular complication of liver disease that occurs in 5-32% of patients with cirrhosis. The presence of HPS markedly increases mortality. No effective medical therapies are currently available and liver transplantation is the only established treatment option for HPS. The definition and diagnosis of HPS are established by the presence of a triad of liver disease with intrapulmonary vascular dilation that causes abnormal arterial gas exchange. Experimental biliary cirrhosis induced by common bile duct ligation in the rat reproduces the pulmonary vascular and gas exchange abnormalities of human HPS and serves as a pertinent animal model. Pulmonary microvascular dilation and angiogenesis are two central pathogenic features that drive abnormal pulmonary gas exchange in experimental HPS, and thus might underlie HPS in humans. Defining the mechanisms involved in the microvascular alterations of HPS has the potential to lead to effective medical therapies. This Review focuses on the current understanding of the pathogenesis, clinical features and management of HPS.

Detection of hepatopulmonary syndrome in patients with liver cirrhosis using 3D contrast echocardiography

BACKGROUND AND STUDY AIMS

Hepatopulmonary syndrome (HPS) is characterised by the triad of advanced liver disease, arterial hypoxaemia and intrapulmonary vascular dilatation (IPVD). The present study aimed to evaluate HPS in patients with liver cirrhosis and the role of three-dimensional (3D) contrast echocardiography in the detection of this syndrome.

PATIENTS AND METHODS

A total of 78 chronic liver disease patients aged 42 ± 11 years fulfilled the criteria for this study and were subjected to clinical examination, laboratory investigations, arterial blood gases measurement, pulmonary function tests, upper gastrointestinal endoscopy, 3D contrast echocardiography and computed tomography (CT) pulmonary angiography.

RESULTS

According to 3D contrast echocardiography results, we divided the patients into a positive group (n=26) in which patients showed a delayed appearance of contrast in left heart chambers and a negative group (n=52). Among 26 patients of the positive group, nine had hypoxaemia (partial pressure of oxygen (PaO(2)) <70 mm Hg) and were diagnosed as having hepatopulmonary syndrome (HPS), the other 17 who had shown echocardiographic evidence of IPVDs but without hypoxaemia were diagnosed as having sub-clinical HPS. This study showed significant correlation between positive contrast echocardiography findings and duration of liver disease, Child score, cyanosis, clubbing, orthodeoxia, portal vein diameter, spleen size and oesophageal varices grades. No significant correlation was found between 3D contrast echocardiography findings and age, sex, spider naevi and pulmonary function tests. Multivariate logistic regression showed that cyanosis, clubbing, orthodeoxia, Child score and portal vein diameter are independent predictors of HPS.

CONCLUSION

Cyanosis, clubbing and platypnoea-orthodeoxia are suggestive indicators of HPS, which can be easily detected by 3D contrast echocardiography which can replace the trans-oesophageal echocardiogram (TEE) in cirrhotic patients.

Pulmonary complications of cirrhosis

Pulmonary vascular complications of liver disease comprise two distinct clinical entities: hepatopulmonary syndrome (HPS-microvascular dilatation and angiogenesis) and portopulmonary hypertension (POPH-vasoconstriction and remodeling in resistance vessels). These complications occur in similar pathophysiologic environments and may share pathogenic mechanisms. HPS is found in 15% to 30% of patients with cirrhosis and its presence increases mortality and the risks of liver transplantation, particularly when hypoxemia is present. Contrast echocardiography and arterial blood gas analysis are required to establish the diagnosis. No medical therapies are available, although liver transplantation is effective in reversing the syndrome. POPH is found in 4% to 8% of patients undergoing liver transplantation evaluation, and the presence of moderate to severe disease significantly increases perioperative transplant mortality. Transthoracic echocardiography is recommended for screening and right-heart catheterization is required to establish the diagnosis. Medical therapies are increasingly effective in improving pulmonary vascular hemodynamics in POPH and may result in better perioperative outcomes.

[Pulmonary affection in advanced liver disease - hepatepulonary syndrome and portopulmonary hypertension]

Patients suffering from severe chronic liver disease, in particular cirrhosis, are at risk for pulmonary complications. The leading clinical symptom is shortness of breath, which can accompany the actual disease as indirect effect because of anemia, faint muscles or ascites. On the other hand, dyspnea can have multiple additive causes in case of accompanying cardial or pulmonary disease. The hepatopulmonary syndrome (HPS) and the portopulmonary hypertension (PoPH) belong to the most relevant pulmonary complications in liver cirrhosis. HPS appears to be more common than PoPH and the presence of either entity increases morbidity and mortality in patients with liver disease. The two diseases have to be strictly distinguished, as they have opposed histological and pathophysiological origin. While the HPS is a dilatative pulmonary- vascular disease, the PoPH is a constrictive or obliterative pulmonary-vascular disease in the context of a liver disease or a portal hypertension. Therefore, these diseases are separate entities also when it comes to diagnostics and therapy.

Long-term outcome and management of hepatopulmonary syndrome in children

We aim to report a single center experience of the management and long term outcome of HPS in pediatric liver transplant recipients. A retrospective review of children with HPS from 1990 to 2004.

INCLUSION CRITERIA

liver disease or portal hypertension, hypoxemia (PaO(2) < 70 mmHg or SaO(2) < 95%) and intrapulmonary shunting documented by macroaggregated albumin scan ratio of >4% (classified mild group [<20%], moderate group [20-40%] and severe group [>40%]). Resolution of HPS post-liver transplant was defined as PaO(2) > 70 mmHg or SaO(2) > 95%. Eighteen children (six male [34%], median age at diagnosis of HPS 8.6 [1-15.5] yr) had HPS: biliary atresia (n = 8), idiopathic biliary cirrhosis (n = 4), progressive intrahepatic cholestasis (n = 2), miscellaneous (n = 4). The majority had mild shunting (n = 8). Fourteen underwent transplantation with resolution of HPS in 13. Six developed complications: hepatic artery thrombosis (n = 4), biliary (n = 2). Four children died (28%), two pretransplant. There was a tendency towards shunt fraction worsening to a slower degree over time. One-yr survival rate post-transplant was 93%. Median PaO(2) was significantly lower in non-survivors compared to survivors (43 vs. 55.2 mmHg, p = 0.03). There was correlation between oxygen parameters pretransplant and time to HPS resolution post-transplant. HPS is reversible after transplant, but is associated with increasing mortality and morbidity.

Impact of hepatopulmonary syndrome on quality of life and survival in liver transplant candidates

BACKGROUND & AIMS

Hepatopulmonary syndrome (HPS) affects 10%-30% of patients with cirrhosis and portal hypertension, but the impact on functional status, quality of life, and survival is poorly defined. We assessed the impact of HPS in patients evaluated for liver transplantation.

METHODS

We performed a prospective multicenter cohort study of patients being evaluated for liver transplantation in 7 academic centers in the United States. Patients with HPS (defined as an increased alveolar-arterial oxygen gradient with intrapulmonary vasodilation) were compared with those without HPS in terms of demographics and clinical variables. New York Heart Association functional class, quality of life, and survival were assessed.

RESULTS

Seventy-two patients with HPS and 146 patients without HPS were compared. There were no differences in age, sex, or etiology or severity of liver disease between the groups; however, patients with HPS were less likely to have a history of smoking (P = .03). Patients with HPS had worse New York Heart Association functional class (P = .005) and had significantly worse quality of life in certain domains compared with patients without HPS. In addition, patients with HPS also had a significantly increased risk of death compared with patients without HPS despite adjustment for age, sex, race/ethnicity, Model for End-Stage Liver Disease score, and liver transplantation (adjusted hazard ratio = 2.41; 95% confidence interval, 1.31-4.41; P = .005).

CONCLUSIONS

HPS was associated with a significant increase in risk of death as well as worse functional status and quality of life in patients evaluated for liver transplantation.

Current concepts in the management of hepatopulmonary syndrome

The hepatopulmonary syndrome is characterized as the triad of liver disease, pulmonary gas exchange abnormalities leading to arterial deoxygenation and evidence of intrapulmonary vascular dilatations. This review summarizes the pathological mechanisms leading to pulmonary vascular changes in hepatopulmonary syndrome. The role of the three currently used diagnostic imaging modalities of contrast-enhanced echocardiography, perfusion lung scanning and pulmonary arteriography that identify the presence of intrapulmonary vascular abnormalities are reviewed. Liver transplantation is considered to be the definitive treatment of hepatopulmonary syndrome with often successful reversal of hypoxemia, however other treatments have been trialed. This review further appraises the evidence for the use of pharmacological agents and the role of radiological interventions in hepatopulmonary syndrome.

Intestinal endotoxemia plays a central role in development of hepatopulmonary syndrome in a cirrhotic rat model induced by multiple pathogenic factors

AIM: To characterize the correlation between severity of hepatopulmonary syndrome (HPS) and degree of hepatic dysfunction, and to explore how intestinal endotoxemia (IETM) affects the development of HPS in cirrhotic rats.

METHODS: Male Wister rats were fed with a diet containing maize flour, lard, cholesterol, and alcohol and injected subcutaneously with CCl₄ oil solution every two days for 8 wk to induce typical cirrhosis and development of HPS. The animals were also given a nitric oxide (NO) production inhibitor, N^ω-nitro-L-arginine methyl ester (L-NAME) intraperitoneally, and an iNOS inhibitor, aminoguanidine hydrochloride (AG) via gavage daily from the end of the 4th wk to the end of the 6th or 8th wk, or a HO-1 inhibitor, zinc protoporphyrin (ZnPP) intraperitoneally 12 h prior to killing. Blood, liver and lung tissues were sampled.

RESULTS: Histological deterioration of the lung paralleled to that of the liver in the cirrhotic rats. The number of pulmonary capillaries was progressively increased from 6.1 ± 1.1 (count/filed) at the 4th wk to 14.5 ± 2.4 (count/filed) at the 8th wk in the cirrhotic rats. Increased pulmonary capillaries were associated with increased blood levels of lipopolysaccharide (LPS) (0.31 ± 0.08 EU/mL vs control 0.09 ± 0.03 EU/mL), alanine transferase (ALT, 219.1 ± 17.4 U/L vs control 5.9 ± 2.2 U/L) and portal vein pressure. Compared with normal control animals, the number of total cells in bronchoalveolar lavage fluid (BALF) of the cirrhotic rats at the 8th wk was not changed, but the number of macrophages and the ratio of macrophages to total cells were increased by nearly 2-fold, protein expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) started to increase significantly at the 4th wk, and reached its peak at the 8th wk in the lung of cirrhotic rats. The increase of iNOS expression appeared to be quicker than that of eNOS. NO₂^-/NO₃^- was also increased, which was correlated to the increase of iNOS (r = 0.7699, P < 0.0001) and eNOS (r = 0.5829, P < 0.002). mRNA expression of eNOS and iNOS was highly consistent with their protein expression.

CONCLUSION: Progression and severity of HPS as indicated by both increased pulmonary capillaries and histological changes are closely associated with LPS levels and progression of hepatic dysfunction as indicated by increased levels of ALT and portal vein pressure. Intestinal endotoxemia plays a central role in the development of HPS in the cirrhotic rat model by inducing NO and/or CO.

Pediatric hepatopulmonary syndrome is seen with polysplenia/interrupted inferior vena cava and without cirrhosis

Hepatopulmonary syndrome (HPS) is a triad of liver dysfunction, hypoxemia, and intrapulmonary vascular dilatation. We describe the prevalence and clinical features of HPS at a pediatric liver transplant center. Patients referred to Children's Healthcare of Atlanta/Emory University transplant program from February 1999 to May 2005 were reviewed. Oxygen saturation in room air was screened by percutaneous pulse oximetry. HPS cases were compared with similar age non-HPS recipients (n = 38) to determine differences in clinical characteristics, Pediatric End-Stage Liver Disease (PELD) scores, and posttransplantation survival. Of 211 patients referred and 114 patients transplanted, 7 met criteria for HPS (3.3% and 6.1%, respectively). Patients with HPS had lower PELD score (-0.4 +/- 5.9 vs. 11 +/- 11; P = 0.01) and total bilirubin (1.7 +/- 1.1 vs. 11.2 +/- 10.1; P = 0.02) at the time of transplantation. Four of 7 patients with HPS had polysplenia/interrupted inferior vena cava (PS/IVC) compared with 0 of 38 age-matched controls (P = 0.0002). Three patients with HPS did not have cirrhosis; 2 of these 3 had PS/IVC. All HPS cases normalized room air oxygen saturation by 6 months, and survival after transplantation in HPS cases was 100%. Marked hepatic synthetic or biochemical dysfunction may not be present, and cirrhosis is not a requirement for the development of HPS in children. HPS in children is frequently associated with PS/IVC. Histologic evidence of abnormal intrahepatic portal vein flow and the demonstration of portosystemic communications at any level should be sought in children presenting with unexplained intrapulmonary vascular dilatation. Liver transplantation for HPS in childhood may be appropriate even in the absence of cirrhosis.

Pretransplant management of the cirrhotic patient

Cirrhosis is the twelfth commonest cause of death in the United States, with more than 27,000 deaths and more than 421,000 hospitalizations annually. Currently, there are more than 17,000 patients awaiting liver transplantation in the United States across the 11 United Network for Organ Sharing regions. Approximately 10% of such patients will die awaiting transplantation.

An unusual cause of dyspnoea complicating right upper abdominal swelling

A middle aged, non-addict male presented with right upper abdominal pain and swelling with respiratory distress. Examination revealed central cyanosis, bipedal pitting edema with prominent epigastric and back veins. Liver was enlarged, tender, spanned 20 cm without any splenomegaly or ascites. Other systems were clinically normal. Laboratory investigations showed polymorphonuclear leucocytosis with slightly deranged liver function. Abdominal ultrasonography showed an abscess in the right lobe of the liver with compressed inferior vena cava (IVC), middle and left hepatic veins. Arterial blood gas (ABG) documented hypoxia with orthodeoxia and air-contrast echocardiography was suggestive of an intrapulmonary shunt. A diagnosis of hepato-pulmonary syndrome (HPS) was made with near normal liver function secondary to amebic liver abscess. It reversed completely following successful treatment of the liver abscess.

Hepatopulmonary syndrome in patients with hypoxic hepatitis

BACKGROUND & AIMS

The hepatopulmonary syndrome (HPS) is defined as the triad of liver disease, arterial deoxygenation, and widespread pulmonary vasodilatation. Hypoxic hepatitis, also known as ischemic hepatitis, is the leading cause of acute liver impairment in hospitals. It is unknown whether HPS occurs in hypoxic hepatitis. We assessed the prevalence and clinical consequences of HPS in patients with hypoxic hepatitis.

METHODS

Forty-four patients with hypoxic hepatitis were screened prospectively for HPS using established criteria: (1) presence of hepatic disease, (2) increased alveolar-arterial difference for the partial pressure of oxygen greater than the age-related threshold, and (3) intrapulmonary vasodilatation detected via contrast-enhanced echocardiography. Sixty-two critically ill patients with different cardiopulmonary diseases but without hepatic disease were screened for prevalence of intrapulmonary vasodilatation as a control group.

RESULTS

Criteria of HPS were fulfilled in 18 patients with hypoxic hepatitis. HPS-positive patients had a significantly decreased partial pressure of arterial oxygen (P = .001) and partial pressure of arterial oxygen/fraction of inspired oxygen ratio (P = .034) at the time of diagnosis of HPS, a significant decreased area under the curve of the partial pressure of arterial oxygen/fraction of inspired oxygen ratio during the first 48 hours after diagnosis of hypoxic hepatitis (P = .009), and a significantly increased peak serum aspartate transaminase level (P = .028), compared with patients without HPS. Complete resolution of intrapulmonary vasodilatation was observed during follow-up evaluation. Contrast-enhanced echocardiography was negative for intrapulmonary vasodilatation in all 62 control patients.

CONCLUSIONS

Intrapulmonary vasodilatation indicating HPS frequently occurs in patients with hypoxic hepatitis. It is reversible after normalization of the hepatic dysfunction. Clinicians should consider intrapulmonary vasodilatation and HPS in patients with hypoxic hepatitis.

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.

Effect of oral garlic on arterial oxygen pressure in children with hepatopulmonary syndrome

AIM: To study the effect of oral garlic on arterial oxygen pressure in children with hepatopulmonary syndrome.

METHODS: Garlic powder in a capsule form was given to 15 children with hepatopulmonary syndrome (confirmed by contrast echocardiography) at the dosage of 1 g/1.73 m² per day. Patients were evaluated clinically and by arterial blood gas every four weeks.

RESULTS: The garlic capsule was administered to 15 patients with hepatopulmonary syndrome. There were 10 boys and 5 girls with a mean age of 9.4 ± 3.9 years. The underlying problems were biliary tract atresia (4 patients), autoimmune hepatitis (4 patients), cryptogenic cirrhosis (4 patients) and presinusoidal portal hypertension (3 patients). Eight patients (53.3%) showed an increase of 10 mmHg in their mean arterial oxygen pressure. The baseline PaO₂ was 65.6 ± 12.1 mmHg in the responder group and 47.1 ± 11.2 mmHg in non-responder group. At the end of treatment the mean PaO₂ in responders and non-responders was 92.2 ± 7.75 mmHg and 47.5 ± 11.87 mmHg, respectively (P < 0.01).

CONCLUSION: Garlic may increase oxygenation and improve dyspnea in children with hepatopulmonary syndrome.

The pulmonary involvement in portal hypertension: portopulmonary hypertension and hepatopulmonary syndrome

Pulmonary abnormalities are common in patients with advanced chronic liver disease. Two distinct syndromes strictly related to the presence of portal hypertension, but clearly different from a pathophysiologic point of view, have been identified. Portopulmonary hypertension, characterized by an increased pulmonary arterial pressure, is due to a progressive arteriolar vasoconstriction induced by excess local production of vasoconstrictor substances. Hepatopulmonary syndrome results from intrapulmonary microvascular dilation caused by an inadequate synthesis or metabolism of putative pulmonary vasoactive substances leading to a functional vasodilation of the pulmonary vasculature, ultimately leading to hypoxemia. Controversies on pathogenesis imply different tentative therapeutic approaches for the medical management of these conditions. The development of portopulmonary hypertension or the hepatopulmonary syndrome has important clinical and prognostic implications facing the impact of new therapeutic strategies for the management of the main complications of advanced liver diseases on cardiopulmonary function.

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.

The Incidence of self-prescribed oral complementary and alternative medicine use by patients with gastrointestinal diseases

GOALS

To assess the incidence of oral complementary and alternative medicine (CAM) usage by gastroenterology patients at a single university center and compare against controls.

BACKGROUND

The public awareness and usage of CAM have increased. The use of CAM has been described in patients with functional bowel disorders; however, their role in patients with gastrointestinal disease is less clear.

STUDY

Patients attending luminal gastroenterology clinics and customers at local supermarkets completed a 30-point, structured questionnaire assessing their use of CAM.

RESULTS

A total of 1,409 subjects were recruited. The incidence of CAM use was 49.5% for inflammatory bowel disease, 50.9% for irritable bowel syndrome, 20% for general gastrointestinal diseases, and 27% for controls. Pearson's chi(2) tests showed that patients with inflammatory bowel disease (IBD) or irritable bowel syndrome were more likely to use CAM than controls (P < 0.001). Binary logistic regression analysis showed that females were more likely to take CAM than men (P < 0.05).

CONCLUSIONS

The percentage of CAM users among patients with IBD is similar to those with a functional diagnosis. Increasing numbers of IBD patients are using CAM in addition to conventional therapy. Awareness of this may prevent adverse CAM and conventional drug interactions.

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.

Increased pulmonary vascular endothelin B receptor expression and responsiveness to endothelin-1 in cirrhotic and portal hypertensive rats: a potential mechanism in experimental hepatopulmonary syndrome

BACKGROUND/AIMS

In experimental hepatopulmonary syndrome (HPS), hepatic endothelin-1 (ET-1) release during common bile duct ligation (CBDL) and ET-1 infusion in pre-hepatic portal hypertension after portal vein ligation (PVL) initiate vasodilatation through an endothelin B receptor mediated increase in pulmonary endothelial nitric oxide synthase (eNOS). We evaluated if pulmonary ET receptor expression changes in experimental cirrhosis and portal hypertension and confers susceptibility to HPS.

METHODS

In normal, PVL and CBDL animals, lung ET receptor expression and localization were assessed and ET receptor levels and functional analysis of ET-1 effects on eNOS levels were evaluated in intralobar pulmonary artery (PA) and aortic (AO) segments. Normal rats underwent evaluation for HPS after ET-1 infusion.

RESULTS

There was a selective increase in ET(B) receptor expression in the pulmonary vasculature from PVL and CBDL animals. ET-1 stimulated NO production and an ET(B) receptor mediated increase in eNOS levels in PA segments from PVL and CBDL animals, but not normal animals. ET-1 did not alter lung eNOS levels or cause HPS in normal rats.

CONCLUSIONS

ET(B) receptor expression and ET-1 mediated eNOS and NO production are enhanced in the lung vasculature in cirrhotic and portal hypertensive animals and correlate with in vivo susceptibility to ET-1 mediated HPS.

Hepatopulmonary Syndrome and Portopulmonary Hypertension

In patients with hepatopulmonary syndrome, supplemental oxygen and liver transplantation are the usual treatments of choice. Pharmacologic approaches have limited success in improving hypoxemia. Interventional radiology procedures may improve arterial hypoxemia in highly selected patients. In patients with portopulmonary hypertension, continuous infusion with intravenous epoprostenol (prostaglandin I(2)) can significantly improve pulmonary hemodynamics. Outcome following liver transplantation is variable; increased cardiopulmonary mortality occurs in patients with moderate to severe pulmonary hypertension.

Occurrence of hepatopulmonary syndrome in Budd-Chiari syndrome and the role of venous decompression

BACKGROUND & AIMS

Hepatopulmonary syndrome (HPS) has been predominantly detected in cirrhotic patients and rarely in patients with noncirrhotic portal hypertension. The aim of this study was to determine the occurrence of HPS in patients with Budd-Chiari syndrome (only anecdotal reports available) and evaluate the role of venous decompression in its reversal.

METHODS

Twenty-nine consecutive cases of Budd-Chiari syndrome without primary cardiopulmonary disease were investigated by air contrast echocardiography and arterial blood gas analysis. Venous decompression (e.g., by balloon cavoplasty) was attempted when feasible.

RESULTS

Eight cases (27.6%) of HPS and 9 cases (31.0%) with positive contrast echocardiography but unimpaired oxygenation were detected. Duration of disease was longer (P = 0.026) among those with positive contrast echocardiography. Cavoplasty reversed 4 of 5 cases of HPS and 2 of 2 cases with positive contrast echocardiography alone. Venous decompression by drainage of amebic liver abscess (which was compressing hepatic venous outflow) also reversed 1 case of HPS. HPS was relieved by venous decompression in 5 of 6 cases.

CONCLUSIONS

HPS developed in a substantial fraction of our patients with Budd-Chiari syndrome, with positive contrast echocardiography occurring mainly in the benign, slowly progressing variety. Venous decompression showed promise in reversing such cases.

Hepatopulmonary Syndrome and Portopulmonary Hypertension

In patients with hepatopulmonary syndrome, supplemental oxygen and liver transplantation are the usual treatments of choice. Pharmacologic approaches have limited success in improving hypoxemia. Interventional radiology procedures may improve arterial hypoxemia in highly selected patients. In patients with portopulmonary hypertension, continuous infusion with intravenous epoprostenol (prostaglandin I(2)) can significantly improve pulmonary hemodynamics. Outcome following liver transplantation is variable; increased cardiopulmonary mortality occurs in patients with moderate to severe pulmonary hypertension.