Prevalence of hepatopulmonary syndrome in children

Systemic Complications Secondary to Chronic Liver Disease

The systemic sequelae of chronic liver disease (CLD) may be due to portal hypertension and shunting, malnutrition, and/or a low grade inflammatory state. This article will focus on the consequences of chronic liver disease affecting extrahepatic organs. Portal hypertension underlies many systemic complications of CLD. Aside from varices and ascites, portal hypertension may cause both hepatopulmonary syndrome and portopulmonary hypertension leading to respiratory compromise. Cardiomyopathy may also occur secondary to end stage liver disease. Hepatorenal syndrome is also well recognised and hepatic encephalopathy is a consequence of the effect of liver dysfunction on the brain. Compromise of the immune system is well described in end-stage liver disease leading to sepsis and its consequences. Bony disease including osteoporosis and hepatic arthropathy may both be seen in children with CLD. CLD may be asymptomatic initially but then complications may present as the disease progresses. Furthermore, systemic effects of end stage liver disease may complicate liver transplant. These complications often present insidiously or at the time of acute decompensation. Thus, it is important that healthcare providers are vigilant when caring for children with CLD. This article outlines the secondary complications of CLD with an overview of the definition and diagnosis, pathophysiology, management and prognosis of each.

Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease exception policy and outcomes in pediatric patients with hepatopulmonary syndrome requiring liver transplantation

Hepatopulmonary syndrome (HPS) is associated with increased waitlist mortality in liver transplantation (LT) candidates. Children with HPS are granted Model for End-Stage Liver Disease (MELD)/Pediatric End-Stage Liver Disease (PELD) exception points for waitlist prioritization in the United States based on criterion developed for adults. In this study, the impact of this MELD/PELD exception policy on post-LT survival in children was examined. A retrospective cohort of patients aged younger than 18 years with a MELD/PELD exception request who underwent LT between 2007 and 2018 were identified in the Scientific Registry of Transplant Recipients. Patients were stratified by waitlist partial pressure of arterial oxygen (PaO 2 ) to assess risk factors for waitlist mortality and post-LT survival. Among 3082 pediatric LT recipients included in the study, 124 patients (4%) received MELD/PELD exception points for HPS. Patients with HPS were a median age of 9 years (interquartile range: 6, 12 years), 54.8% were girls, and 54% were White. Most patients (87.9%) were listed with laboratory MELD/PELD scores <15. Waitlist mortality for patients with HPS exception points was rare and not different from patients without HPS. When stratified by pre-LT PaO 2 , hypoxemia severity was not associated with differences in 1-, 3-, or 5-year survival rates after LT ( p = 0.13). However, patients with HPS showed a slightly lower survival rate at 5 years compared with patients without HPS (88.7% vs. 93.4%; p = 0.04). MELD/PELD exceptions for children with HPS mitigated waitlist mortality, and recipients with HPS experienced excellent 5-year survival after LT, although slightly lower than in patients without HPS. Unlike adults with HPS, the severity of pre-LT hypoxemia in children does not impact post-LT survival. These data suggest that adult criteria for granting MELD/PELD exception points may not appropriately capture HPS severity in pediatric patients. Further prospective multicenter studies to examine the risk factors predicting negative survival outcomes in children with HPS are warranted.

Beyond Varices: Complications of Cirrhotic Portal Hypertension in Pediatrics

Complications of cirrhotic portal hypertension (PHTN) in children are broad and include clinical manifestations ranging from variceal hemorrhage, hepatic encephalopathy (HE), ascites, spontaneous bacterial peritonitis (SBP), and hepatorenal syndrome (HRS) to less common conditions such as hepatopulmonary syndrome, portopulmonary hypertension, and cirrhotic cardiomyopathy. The approaches to the diagnosis and management of these complications have become standard of practice in adults with cirrhosis with many guidance statements available. However, there is limited literature on the diagnosis and management of these complications of PHTN in children with much of the current guidance available focused on variceal hemorrhage. The aim of this review is to summarize the current literature in adults who experience these complications of cirrhotic PHTN beyond variceal hemorrhage and present the available literature in children, with a focus on diagnosis, management, and liver transplant decision making in children with cirrhosis who develop ascites, SBP, HRS, HE, and cardiopulmonary complications.

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

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

Hepatopulmonary Syndrome: A Nationwide Analysis of Epidemiological Trends and Outcomes From 2012 to 2018

Background

This study was designed to determine the epidemiological trends and adverse outcomes of hepatopulmonary syndrome (HPS).

Methods

This retrospective interrupted trend study analyzed data from the Nationwide Inpatient Sample (NIS) for the years 2012, 2014, 2016 and 2018 to identify adult (≥ 18 years) hospitalizations with a diagnosis of HPS. We highlighted epidemiological trends for HPS. Inpatient mortality, mean length of stay (LOS) and mean total hospital charge (THC) were estimated using multivariate regression trend analysis.

Results

We observed an increase in the total number of HPS hospitalizations from 1,565 in 2012 to 2,495 in 2018, with mean age ranging from 55.8 to 58.1 years. There was a trend towards increasing hospitalizations (P-trend < 0.001) with increasing mean age (P-trend = 0.003) for HPS. Whites made up most of the study population. The inpatient mortality for HPS ranged from 12.4% to 12.6%, but there was no statistically significant trend for mortality (P-trend = 0.534) between 2012 and 2018. Additionally, there was no change in both mean LOS (P-trend = 0.545) and mean THC (P-trend = 0.534) for HPS for these years.

Conclusions

Hospitalizations and mean age for HPS were on the rise. Inpatient mortality ranged from 12.4% to 12.6%; however, a statistically significant trend for mortality was absent.

Reliable Detection of Intrapulmonary Shunts Using Contrast-Enhanced Echocardiography in Children With Portal Hypertension or Portosystemic Shunt

OBJECTIVES

The aim of this study was to analyze if contrast-enhanced echocardiography (CEE) is as reliable as lung perfusion scintigraphy (LPS) to detect intrapulmonary shunting (IPS) in children with portal hypertension (PHTN) or congenital/surgical portosystemic shunts (PSS) and to define the number of cardiac cycles required to exclude intrapulmonary shunting.

METHODS

Inclusion criteria for this cross-sectional study were: (1) presence of PHTN or PSS diagnosed on abdominal ultrasound, (2) technically valid saline contrast echocardiography, (3) lung perfusion scintigraphy within 6 months of CEE. The number of cardiac cycles between right atrial opacification and the arrival of contrast in the left atrium were counted. We analyzed our CEE data at three and five cardiac cycles and compared them with LPS results.

RESULTS

The study population was composed of 78 children (38 girls, 49%) ages 2.1-18.8 years (mean 9.8). Sixty-nine patients had PHTN (88%), and nine had a PSS (11%). Eleven subjects (14%) presented evidence of IPS on LPS. Peripheral oxygen saturation was lower in the subjects with IPS detected on LPS (95.3 ± 1.7% vs 99.0 ± 1.4%; P < 0.01). Comparison of LPS with CEE before three and five cardiac cycles showed that CEE is highly specific (95.7%) as early as three cardiac cycles with markedly better sensitivity (72.7%) when using five cardiac cycles. Furthermore, a negative study using five cardiac cycles ruled out IPS with a 95% negative predictive value. The cardiac cycle at which the bubbles appeared in the left atrium was inversely correlated to the shunt index measured using LPS (r = -0.563; P = 0.001).

CONCLUSION

CEE is sufficient for the screening of IPS in children with PHTN or congenital/surgical PSS, obviating the need for LPS.

Non-invasive assessment of intrapulmonary shunt and ventilation to perfusion ratio in children with hepatopulmonary syndrome before and after liver transplantation

OBJECTIVES

To use the oxyhaemoglobin dissociation curve (ODC) to non-invasively measure the ventilation perfusion ratio (V_A/Q) and right-to-left intrapulmonary vascular shunt before and after liver transplantation (LT) in children with hepatopulmonary syndrome (HPS). To investigate whether the right-to-left shunt derived by ODC correlated with the shunt derived by technetium-99 labelled macroaggregated albumin lung perfusion scan (MAA).

METHODS

A retrospective cohort study at King's College Hospital NHS Foundation Trust, London, UK was performed between 1998 and 2016. The V_A/Q and right-to-left shunt were non-invasively measured pre and post LT. The pre-LT right-to-left intrapulmonary shunt was also measured by MAA. The non-invasively derived pre-LT shunt was correlated with the shunt derived by MAA.

RESULTS

Fifteen children with HPS were studied with a median (IQR) age at LT of 8.8 (6.6-12.9) years. The median (IQR) pre-LT V_A/Q [0.49 (0.42-0.65)] was lower compared to the post-LT V_A/Q [0.61 (IQR 0.54-0.72), p = 0.012]. The median (IQR) pre-LT shunt was 19 (3-24) % which decreased to zero in all but one children post-LT, (p = 0.001). The MAA-derived shunt was significantly positively correlated with the ODC-derived shunt (r = 0.783, p = 0.001). The mean (SD) difference between shunt derived by ODC and shunt derived by MAA was 0.5 (7.2) %.

CONCLUSIONS

Ventilation/perfusion impairment reverses but not completely resolves after liver transplantation in children with hepatopulmonary syndrome. The non-invasive method for estimating intrapulmonary shunting could be used as an alternative to the macroaggregated albumin scan in this population.

Clinical outcomes and risk factors of hepatopulmonary syndrome in children

Hepatopulmonary syndrome (HPS) is defined as three distinct features: liver disease, hypoxemia, and intrapulmonary vasodilation. The purpose of this study was to investigate the clinical outcomes of pediatric HPS and to identify the risk factors for HPS in children with biliary atresia (BA). We performed a retrospective cohort study of all children who were diagnosed with HPS between 2000 and 2018 at Seoul National University Hospital. The clinical features and outcomes of the 10 patients diagnosed with HPS were reviewed. To clarify the risk factors of HPS in patients with BA, we reviewed 120 patients diagnosed with BA. Underlying liver disease was BA in 8 patients, portal vein agenesis in 1 patient, and portal vein thrombosis in 1 patient. A total of 7 patients underwent liver transplantation (LT). Currently, all seven patients, including 3 patients with severe HPS, survived after LT. The prevalence of HPS in children with BA was 7%. Polysplenia/interrupted inferior vena was the only risk factor for HPS in BA patients in multivariate analysis. The Pediatric End-Stage Liver Disease score was not associated with the development of HPS. Children with severe HPS undergoing LT had excellent outcomes. Screening for HPS in children with BA is required regardless of the severity of liver diseases.

Comparison of Two Diagnostic Criteria for Hepatopulmonary Syndrome-High Prevalence in Biliary Atresia

OBJECTIVES

There is lack of clarity regarding the exact prevalence of hepatopulmonary syndrome (HPS) in pediatric liver diseases owing to lack of standardized diagnostic criteria. Thus, we aimed to do a comparative study of HPS with respect to its prevalence using the available diagnostic criteria.

METHODS

All consecutive children with biliary atresia (BA) and other chronic liver diseases (CLDs) were studied. Prevalence of HPS was compared using the 2 available criteria: demonstration of intrapulmonary vascular dilatation along with either alveolar-arterial oxygen difference (P [A-a] O2) on arterial blood gas analysis of more than 15 mmHg (criteria 1), or higher than age-appropriate calculated value for P (A-a) O2 (criteria 2).

RESULTS

A total of 42 children in BA group and 62 in the non-BA CLD group were included. Using the criteria 1, the prevalence of HPS was 42.3%: 57.1% in the BA group and 32.2% in the CLD group, whereas using criteria 2, the prevalence was 48.1%: 61.9% in the BA group and 38.7% in the CLD group. Criteria 2 diagnosed 6 additional patients with HPS compared to criteria 1 (P value 0.405). BA subjects had higher risk (2.9-3 folds) of developing HPS compared to other CLDs.

CONCLUSION

There is high prevalence of HPS in pediatric liver disease subjects. Age-appropriate formula for HPS diagnosis may be better applicable in pediatric population. BA subjects have a higher risk of developing HPS compared to other CLDs overall, irrespective of the severity of liver disease and/or portal hypertension.

Hepatopulmonary Syndrome with Right-to-left Shunt in Cirrhotic Patients Using Macro-Aggregated Albumin Lung Perfusion Scan: Comparison with Contrast Echocardiography and Association with Clinical Data

Objectives:

The diagnosis of hepatopulmonary syndrome (HPS) which is a common complication in cirrhotic patients is still subject to debate. This study investigated the association of clinical findings with HPS in cirrhotic patients using macro-aggregated albumin lung perfusion scan (^99mTc-MAA lung scintigraphy). In addition, comparison between ^99mTc-MAA lung scintigraphy and contrast echocardiography (CEE) in detection of HPS was also performed.

Methods:

In this study, 27 patients with cirrhosis underwent ^99mTc-MAA lung scintigraphy and contrast echocardiography comparison CEE and the frequency of HPS was assessed in them and also was compared across the other variables.

Results:

The ^99mTc-MAA lung scintigraphy showed HPS in 13 patients (48.1%) while CEE demonstrated HPS in 5 patients with cirrhosis (18.51%). HPS was mild in 40.74% (11/27) of the patients, and severe in only 2 patients. There was no relationship between gender, disease duration, having diagnosis of disease previously, pulmonary symptoms and Child-Pugh score variations and HPS (p>0.05). Comparison of hemodynamic indices, arterial blood gas analysis and laboratory indices between patients with and without HPS was also non-significant (p value >0.05). Among coagulation factors assessed in cirrhotic patients, we found only significant correlation between HPS and prothrombin time (p<0.05).

Conclusion:

HPS, particularly its mild form, is noted in a great number of patients with cirrhosis using 99mTc-MAA lung scintigraphy. Because of its technical ease, and possibility to obtain objective quantitative information, ^99mTc-MAA lung scintigraphy can be complementary to other diagnostic methods in the evaluation of HPS assessment, although additional studies are needed.

Natural history, risk factors, and outcome of hepatopulmonary syndrome in pediatric liver diseases

BACKGROUND

Limited pediatric literature is available regarding hepatopulmonary syndrome (HPS) especially in subjects with biliary atresia (BA) despite its proven prognostic significance. Thus, we aimed to study the natural history, risk factors, and outcome of HPS in BA and other chronic liver disease (CLD) subjects.

METHODS

All children (BA and other non-BA CLDs) older than 6 months of age were included in the study. HPS was diagnosed on the basis of standard international criteria. Also, fractional exhaled nitric oxide (FeNO) was measured at baseline.

RESULTS

During the study period from January 2017 to December 2018, there were 42 children in BA and 62 in the CLD group. The overall prevalence of HPS was 42.3%: 57.1% in the BA group and 32.2% in the CLD group. Median age at HPS diagnosis was 14.4 months and 90 months in the BA and non-BA CLD groups, respectively. By the end of study period, the prevalence of HPS in the BA group further increased to 73.8% at 0.7% per month. Lower serum albumin (p < 0.05) in BA and higher splenic Z scores (p 0.013) in other CLDs were found to be significant risk factors for HPS. FeNO measurement did not reach diagnostic significance.

CONCLUSION

Prevalence of HPS is higher and also develops at an earlier age in the BA group compared to other CLDs. Also, risk of HPS development increases with increasing disease duration in BA. Lower serum albumin in BA and higher splenic Z scores in other CLDs may predict risk for HPS development.

Prevalence and characteristics of hepatopulmonary syndrome in children with cirrhosis in southern Brazil

BACKGROUND

Hepatopulmonary syndrome (HPS) is defined as a triad characterized by arterial deoxygenation, intrapulmonary vascular dilatations (IPVDs), and liver disorder. The aims of this study were to assess the prevalence of HPS in children with cirrhosis, the clinical characteristics of patients with HPS, and the tests used for the diagnosis of IPVD.

PATIENTS AND METHODS

This was a prospective, cross-sectional study of 40 children with cirrhosis (median age: 44 months). Investigations of HPS included arterial blood gas analysis, contrast-enhanced transthoracic echocardiography (CE-TTE), and perfusion lung scanning using technetium-99m-labeled macroaggregated albumin (Tc-MMA). Patients' clinical characteristics (age, etiology of cirrhosis, and severity of hepatopathy) were assessed. HPS was defined as liver disease; alveolar-arterial oxygen gradient of at least 15 mmHg and/or partial pressure of arterial oxygen less than 80 mmHg; and detection of IPVD by CE-TTE or Tc-MMA scanning. Statistical significance was indicated by a P value less than 0.05.

RESULTS

The prevalence of HPS was 42.5% (17/40). Eight patients had moderate HPS (47%) and two patients had severe HPS (12%). In bivariate analysis, biliary atresia (P=0.033) and median age (10 months; P=0.005) were associated with HPS. In multivariate analysis, only age remained statistically significant (prevalence ratio=0.99; 95% confidence interval=0.98-0.99; P=0.010). Sixteen patients with HPS had IPVD detected by CE-TTE (94.1%) and six patients had IPVD detected by Tc-MMA scanning (35.3%), with no significant agreement between these methods (κ=-0.12; P=0.163).

CONCLUSION

HPS is a common complication of cirrhosis in children. A combination of clinical and imaging criteria should be used to diagnose HPS.

Pulmonary transit time derived from pulmonary angiography for the diagnosis of hepatopulmonary syndrome

BACKGROUND & AIMS

Pulmonary transit time (PTT) is the transit time of blood from the right side of the heart to the left side of the heart. The aim of the present study was to evaluate the role of the PTT derived from pulmonary angiography in the diagnosis of hepatopulmonary syndrome (HPS).

METHODS

From December 2014 to September 2015, all patients with chronic liver disease and/or portal hypertension undergoing a venous interventional radiologic procedure at our institution were eligible for inclusion in this prospective study. Pulmonary angiography was performed in all patients, and the PTT, which was defined as the time between opacification of the pulmonary trunk and the right border of the left atrium, was determined.

RESULTS

A total of 53 patients were included, 20 of whom had a positive contrast-enhanced echocardiography result and an elevated alveolar-arterial oxygen gradient were considered to have HPS. PTT was significantly shorter in patients with HPS than in those without [median, 3.34 (interquartile range, 3.01-3.67) seconds vs 4.0 (interquartile range, 3.67-4.17) seconds; P < .001]. The area under the receiver operating characteristic curve of PTT for diagnosing HPS was 0.83 (95% confidence interval, 0.70-0.92). The optimal cut-off value of PTT for diagnosing HPS, based on Youden's index, was 3.55 seconds. The sensitivity, specificity and accuracy of PTT < 3.55 seconds for diagnosing HPS were 70%, 85% and 79% respectively.

CONCLUSIONS

Pulmonary transit time derived from pulmonary angiography is useful for diagnosing HPS, especially for patients with intracardiac shunts and inadequate echocardiographic windows.

Impact of Bacterial Translocation on Hepatopulmonary Syndrome: A Prospective Observational Study

BACKGROUND/AIMS

Hepatopulmonary syndrome (HPS) is characterized by a defect in oxygenation induced by pulmonary vascular dilatation in cirrhosis. While severe HPS is responsible for a high rate of mortality, the prevalence and pathophysiology of HPS are not fully elucidated. We evaluated the prevalence and pathophysiology of HPS in patients with cirrhosis.

METHODS

A total of 142 patients with cirrhosis who underwent saline-agitated contrast echocardiography were enrolled in this prospective observational study. HPS was defined by positive findings on contrast echocardiography, cirrhosis, and the presence of an oxygenation defect (alveolar-arterial oxygen gradient > 15 mmHg). HPS grades from 0 to 3 were assigned based on the density and spatial distribution of microbubbles in the left ventricle. The primary endpoint was the prevalence of HPS. The secondary endpoints included clinical characteristics and levels of lipopolysaccharide (LPS), LPS-binding protein (LBP), nitric oxide, and endothelin-1 in HPS.

RESULTS

Fifty-nine patients (41.5%) were diagnosed with HPS (grade 1: 24, grade 2: 23, and grade 3: 12 patients). The mean levels of LPS (0.36 ± 0.02, 1.02 ± 0.18, 2.86 ± 0.77, and 6.56 ± 1.46 EU/mL, p < 0.001) and LBP (7026 ± 3336, 11,445 ± 1247, 11,947 ± 1164, and 13,791 ± 2032 ng/mL, p = 0.045) were found to be increased according to HPS grade (negative, grade 1-3). Endothelin-1 levels were significantly elevated according to HPS grade (1.83 ± 0.17, 2.62 ± 0.22, 3.69 ± 0.28, and 4.29 ± 0.34 pg/mL, p < 0.001), demonstrating a significant difference between each grade (p < 0.05).

CONCLUSIONS

HPS is a common complication with a prevalence of 41.5% in patients with cirrhosis. Bacterial translocation and portal pulmonary vascular dilatation are key mechanism involved in the progression of HPS.

Successful venoarterial extracorporeal membrane oxygenation for prolonged hepatopulmonary syndrome following pediatric liver transplantation: A case report and review of the literature

HPS is a major complicating feature of end-stage liver disease. Diagnosis is clinical, and LT is the only definitive treatment. While the general impression is that HPS improves quickly after transplantation, it may not always be the case. We describe the smallest reported child with HPS prior to LT and requiring prolonged venoarterial extracorporeal membrane oxygenation after LT; especially as it is a rare occurrence, physician managing such cases should be aware of the circumstances under which HPS may require specific treatment.

Unexplained cyanosis caused by hepatopulmonary syndrome in a girl with APECED syndrome

Autoimmune polyendocrinopathy, candidiasis and ectodermal dystrophy (APECED) is a rare but devastating primary immunodeficiency disease caused by loss-of-function mutations in autoimmune regulator (AIRE) gene on chromosome 21q22.3. The clinical spectrum of the disease is characterized by a wide heterogeneity because of autoimmune reactions toward different endocrine and non-endocrine organs. Here, we report a 17-year-old Turkish girl diagnosed with APECED at 9 years in whom a novel homozygote mutation in AIRE gene p.R15H (c.44G>A) was found. In the clinical course of the patient, chronic liver disease due to autoimmune hepatitis has evolved resulting in hepatopulmonary syndrome (HPS) which has not been reported before in patients with APECED.

Severe Hepatopulmonary Syndrome in a Child with Caroli Syndrome

Hepatopulmonary Syndrome (HPS) is a potential complication of chronic liver disease and is more commonly seen in the adult population. Caroli Syndrome is a rare inherited disorder characterized by intrahepatic ductal dilation and liver fibrosis that leads to portal hypertension. In children with liver disease, HPS should be considered in the differential diagnosis of prolonged, otherwise unexplained, hypoxemia. The presence of HPS can improve patient priority on the liver transplantation wait list, despite their Pediatric End-Stage Liver Disease (PELD) score. We present a 6-year-old girl with Caroli Syndrome and End-Stage Renal Disease who presented with persistent hypoxemia. The goal of this report is to increase awareness of HPS in children.

Biliary atresia: Indications and timing of liver transplantation and optimization of pretransplant care

Biliary atresia (BA) is a progressive, fibro-obliterative disorder of the intrahepatic and extrahepatic bile ducts in infancy. The majority of affected children will eventually develop end-stage liver disease and require liver transplantation (LT). Indications for LT in BA include failed Kasai portoenterostomy, significant and recalcitrant malnutrition, recurrent cholangitis, and the progressive manifestations of portal hypertension. Extrahepatic complications of this disease, such as hepatopulmonary syndrome and portopulmonary hypertension, are also indications for LT. Optimal pretransplant management of these potentially life-threatening complications and maximizing nutrition and growth require the expertise of a multidisciplinary team with experience caring for BA. The timing of transplant for BA requires careful consideration of the potential risk of transplant versus the survival benefit at any given stage of disease. Children with BA often experience long wait times for transplant unless exception points are granted to reflect severity of disease. Family preparedness for this arduous process is therefore critical. Liver Transplantation 23:96-109 2017 AASLD.

Intrapulmonary vascular dilation in children with chronic liver diseases: pre- and post-liver transplantation

BACKGROUND AND STUDY AIMS

Chronic liver disease (CLD) can cause hepatopulmonary syndrome (HPS), defined as triad of liver disease, hypoxemia, and intrapulmonary vascular dilation (IPVD). The aim of this study was to determine the evidence of IPVD in a cohort of pediatric patients with CLD pre- and post-liver transplantation (LT).

MATERIAL AND METHODS

All pediatric patients with CLD listed for LT were studied. Pulse oxygen saturation (SpO(2)), technetium-99m-labeled macroaggregated albumin ((99m)Tc- MAA) perfusión scan (positive test: uptake of the isotope ≥ 6% in the brain), and echocardiography with saline bubble test (SBT) were performed. SBT was re-evaluated at 3-6 months after LT. Grading of SBT included grade 0 (no bubble), I (1-9 bubbles), grade II (10-20 bubbles), and grade III (> 20 bubbles).

RESULTS

Eighteen patients, median age 22.5 months (8-108), were enrolled. Most had biliary atresia (77.8%). Pre-LT, all patients had SpO(2) of 100% and none had positive (99)mTc- MAA perfusion scan. Two patients (11%) had negative SBT (grade 0), 1 (5.5%) had grade I, 3 (16.5%) had grade II, and 12 (67%) had grade III, respectively. Post-LT SBT became negative in all survivors (n = 16), (p = 0.0001).

CONCLUSIONS

Most cirrhotic children in this cohort study had evidence of IPVD by positive SBT. However, none of these met the criteria for diagnosis of HPS. This evidence of IPVD subsided after LT.

Anesthetic management of a pediatric patient with pulmonary arteriovenous fistula undergoing liver transplantation - a case report

For patients with HPS who require anesthesia for a procedure, HPV should be maintained to prevent worsening hypoxemia. Here, the case of a 9-yr-old girl who was scheduled for a living donor liver transplantation is presented. The patient suffered from end-stage liver disease with HPS due to biliary atresia, which contributed to the development of a diffuse pulmonary AVF. Consequently, anesthetic management of this patient involved two different types of pulmonary shunt. It is important to maintain HPV, not only to prevent worsening of the hypoxia caused by HPS but also to inhibit an increase in PVR that could cause an increase of shunt flow through the pathological fistula. A TIVA technique was performed, and a nitrous oxide inhaler was prepared in case of a possible increase in PVR during the reperfusion period. There were no adverse events during the operation. Thus, anesthesiologists should be aware of the pathophysiological status of HPS and its potential to progress to a pulmonary AVF in order to meticulously determine an anesthesia plan that accounts for the hypoxia and PVR that are associated with HPS.

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.

Autoimmune hepatitis in a child presenting with hepatopulmonary syndrome (HPS)

HPS has been described in 9-20% of children with end-stage liver disease. We present a case of a previously, asymptomatic nine-yr-old incidentally found to have low oxygen saturation. Physical exam was remarkable for digital clubbing, splenomegaly and orthodeoxia. Laboratory evaluation revealed a low platelet count, hyperammonemia, and prolonged coagulation studies. Sonography showed evidence of splenomegaly and portal venous hypertension. High resolution CT thorax and CTA were normal. HPS was confirmed by agitated saline contrast enhanced echocardiography and Tc-99m MAA scan with evidence of intrapulmonary vascular dilatations. Liver biopsy was performed and consistent with autoimmune hepatitis. A high clinical index of suspicion should be maintained for HPS in pediatric patients who have unexplained hypoxemia as typical signs and symptoms of severe liver disease are often absent. In this report, we discuss a case of HPS complicated AIH in a pediatric patient and review the relevant literature.

Hepatopulmonary Syndrome

Hepatopulmonary syndrome (HPS) is a pulmonary complication observed in patients with chronic liver disease and/or portal hypertension, attributable to an intrapulmonary vascular dilatation that may induce severe hypoxemia. Microvascular dilation and angiogenesis in the lung have been identified as pathologic features that drive gas exchange abnormalities in experimental HPS. Pulse oximetry is a useful screening test for HPS, which can guide subsequent use of arterial blood gases. Contrast-enhanced echocardiography, perfusion lung scanning, and pulmonary arteriography are three currently used diagnostic imaging modalities that identify the presence of intrapulmonary vascular abnormalities. The presence of HPS increases mortality and impairs quality of life, but is reversible with liver transplantation. No medical therapy is established as effective for HPS. At the present time, liver transplantation is the only available treatment for HPS.

Hepatopulmonary Syndrome in children: a comparative study of non-cirrhotic vs. cirrhotic portal hypertension

BACKGROUND & AIMS

Hepatopulmonary syndrome in children has not been extensively studied particularly in different subsets of portal hypertension. We prospectively studied hepatopulmonary syndrome in children with cirrhosis and extrahepatic portal venous obstruction. Their comparison might shed light on the pathogenesis of hepatopulmonary syndrome.

METHODS

Between 1 to 18 years of age, 135 children with portal hypertension (cirrhosis 35, extrahepatic portal venous obstruction 100) were studied. Hepatopulmonary syndrome was diagnosed by the presence intrapulmonary shunt using transthoracic contrast echocardiography and hypoxia/orthodeoxia (in arterial blood gas examination). Comparative analyses were done for both the groups, and also intra- and intergroups with and without hepatopulmonary syndrome.

RESULT

Of 135 children, hepatopulmonary syndrome occurred more frequently in cirrhosis (40%) than extrahepatic portal venous obstruction (13%) (P = 0.01). Cirrhotics with hepatopulmonary syndrome were symptomatic (85% vs. 14%, P < 0.001) and had longer disease duration [16(1-120) months vs. 28 (1-168) months, P = 0.01] as compared to cirrhotics without hepatopulmonary syndrome. Prevalence of hepatopulmonary syndrome among cirrhotics did not correlate with the severity of liver disease as assessed by both paediatric end-stage liver disease score and Child-Turcotte-Pugh score. Patients with extrahepatic portal venous obstruction and hepatopulmonary syndrome remain asymptomatic manifesting with clubbing alone (38%).

CONCLUSIONS

Hepatopulmonary syndrome occurs more frequently in cirrhosis, a majority being symptomatic with more severity in comparison to extrahepatic portal venous obstruction having no symptoms and less severity. There seems to be a role of liver dysfunction besides portal hypertension as an added factor in the pathogenesis of hepatopulmonary syndrome.

[Hepatic involvement in hereditary alpha-1-antitrypsin deficiency]

Apha-1-antitrypsin deficiency is an autosomal recessive genetic disorder seen in all races. The molecular defect is a specific mutation of the SERPINA1 gene leading to synthesis of an abnormal protein (alpha-1-antitrypsin Z) that cannot be secreted and polymerizes in the endoplasmic reticulum of hepatocytes. The inter-individual variability in the responses to intracellular stress induced by the accumulation of abnormal polymers and the mechanisms allowing their degradation is, without doubt, responsible for the different clinical manifestations of the disease. The disease affects the liver where the abnormal protein is synthesized and the lung, which is its place of action. Liver involvement is well recognized in homozygous infants of the phenotype ZZ. In this situation the disease may present a varying picture from neonatal cholestasis (about 15% of neonatal defects) to cirrhosis. However, evolution towards cirrhosis affects less than 3% of infants with the ZZ phenotype and it is preceded in 80% of cases by neonatal cholestasis. In adolescents or adults the manifestations associated with alpha-1-antitrypsin deficiency are usually limited to biochemical abnormalities but may lead to cirrhosis or hepatocellular carcinoma. The hepatic disorder and its complications are treated symptomatically though the pulmonary involvement may benefit from substitution treatment. More specific treatments targeting the molecular and cellular abnormalities are the subject of research.

Improved severe hepatopulmonary syndrome after liver transplantation in an adolescent with end-stage liver disease secondary to biliary atresia

Hepatopulmonary syndrome (HPS) is a serious complication of end-stage liver disease, which is characterized by hypoxia, intrapulmonary vascular dilatation, and liver cirrhosis. Liver transplantation (LT) is the only curative treatment modality for patients with HPS. However, morbidity and mortality after LT, especially in cases of severe HPS, remain high. This case report describes a patient with typical findings of an extracardiac pulmonary arteriovenous shunt on contrast-enhanced transesophageal echocardiography (TEE), and clubbing fingers, who had complete correction of HPS by deceased donor LT. The patient was a 16-year-old female who was born with biliary atresia and underwent porto-enterostomy on the 55th day after birth. She had been suffered from progressive liver failure with dyspnea, clubbing fingers, and cyanosis. Preoperative arterial blood gas analysis revealed severe hypoxia (arterial O2 tension of 54.5 mmHg and O2 saturation of 84.2%). Contrast-enhanced TEE revealed an extracardiac right-to-left shunt, which suggested an intrapulmonary arteriovenous shunt. The patient recovered successfully after LT, not only with respect to physical parameters but also for pychosocial activity, including school performance, during the 30-month follow-up period.

Cirrhosis and hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is characterized as a triad: liver disease, intrapulmonary vascular dilatation and arterial hypoxemia. HPS is reported to be present in 4% to 32% of adult patients with end-stage liver disease and in 9%-20% of children. The pathogenesis of HPS has not been clearly identified. Portal hypertension causes impairment in the perfusion of the bowel and increases the enteral translocation of Gram (-) bacteria and endotoxins. This stimulates the release of vasoactive mediators, such as tumor necrosis factor-alpha, heme oxygenase-derived carbon monoxide and nitric oxide. Genetic alterations have not been associated with this syndrome yet; however, cytokines and chemokines have been suggested to play a role. Recently, it was reported that cumulated monocytes lead to the activation of vascular endothelial growth factor-dependent signaling pathways and pulmonary angiogenesis, which plays an important role in HPS pathogenesis. At present, the most effective and only radical treatment is a liver transplant (LT). Cirrhotic patients who are on the waiting list for an LT have a shorter survival period if they develop HPS. Therefore, it is suggested that all cirrhotic cases should be followed closely for HPS and they should have priority in the waiting list.

Pulse oximetry is insufficient for timely diagnosis of hepatopulmonary syndrome in children with liver cirrhosis

OBJECTIVE

To prospectively investigate the prevalence of hepatopulmonary syndrome (HPS), the importance of pulse oximetry in diagnosing HPS, and the longitudinal course after liver transplantation in children with cirrhosis referred for liver transplantation.

STUDY DESIGN

Fifty-six patients aged 1-17 years (mean age, 4.6 ± 5.0 years) with liver cirrhosis were screened for HPS by hyperemic capillary blood gas (CBG) analysis and contrast-enhanced transthoracic echocardiography. Eleven patients were excluded owing to conditions that can produce cardiopulmonary dysfunction, including 5 with cystic fibrosis, 1 with pulmonary arterial hypertension, and 5 with an intracardial shunt. HPS was classified in accordance with the European Respiratory Society Task Force criteria on pulmonary-hepatic disorders. Patient groups were compared for biochemical and clinical characteristics.

RESULTS

Eighteen children (40%) with cirrhosis were intrapulmonary vasodilatation (IPVD)-positive and had a pulse oximetry oxygen saturation level >98%. Two of these patients (11%) exhibited moderate HPS with an elevated alveolar arterial oxygen gradient >15 mm Hg and PaO2 <70 mm Hg; they died before undergoing liver transplantation. The sensitivity and specificity of CBG analysis for detecting elevated alveolar arterial oxygen gradient in children with IPVD was 94% and 53%, respectively. HPS was associated with late hepatoportoenterostomy (P < .04). Liver transplantation led to resolution of HPS in all patients.

CONCLUSION

IPVD is frequent in children with liver cirrhosis (40%). Pulse oximetry is insufficient for timely HPS diagnosis. Pathological CBG analysis data indicate IPVD in the majority of cases, but are imprecise in children aged <2 years. Contrast-enhanced transthoracic echocardiography and CBG analysis are recommended for evaluation of HPS in children with cirrhosis, regardless of liver synthesis capacity and clinical chemistry data.

Pulmonary manifestations in a patient with transaldolase deficiency

Transaldolase deficiency is a newly recognized metabolic disorder. It is an autosomal recessive genetic disease (OMIM #606003). The effects of the defect in the TALDO gene are pleiotropic with a clinical presentation of growth retardation, dysmorphic features, cutis laxa, congenital heart disease, hepatosplenomegaly, pancytopenia, and bleeding tendencies. This is the first report of a child who was diagnosed at birth with transaldolase deficiency who subsequently developed hepatopulmonary syndrome.

Clinico-pathologic findings in children with hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is infrequently reported in children. Clinical-pathological findings in 10 HPS children were compared with non-HPS controls. Six patients had cirrhosis and four had noncirrhotic portal hypertension (NCPH) 40%. Polysplenia and abnormal venous malformations were exclusive to this group. This prevalence of NCPH with systemic venous anomalies suggests that HPS is associated with pulmonary vasoactive factors not cleared by the liver. Hepatopulmonary syndrome should be considered in any patient with hypoxemia and intrapulmonary shunting whether there is overt clinical liver disease or not.

Guidelines for the diagnosis and treatment of extrahepatic portal vein obstruction (EHPVO) in children

INTRODUCTION

Extrahepatic portal vein obstruction is an important cause of portal hypertension among children. The etiology is heterogeneous and there are few evidences related to the optimal treatment.

AIM AND METHODS

To establish guidelines for the diagnosis and treatment of EHPVO in children, a group of gastroenterologists and pediatric surgery experts reviewed and analyzed data reported in the literature and issued evidence-based recommendations.

RESULTS

Pediatric EHPVO is idiopathic in most of the cases. Digestive hemorrhage and/or hypersplenism are the main symptoms. Doppler ultrasound is a non-invasive technique with a high degree of accuracy for the diagnosis. Morbidity is related to variceal bleeding, recurrent thrombosis, portal biliopathy and hypersplenism. Endoscopic therapy is effective in controlling acute variceal hemorrhage and it seems that vasoactive drug therapy can be helpful. For primary prophylaxis of variceal bleeding, there are insufficient data for the use of beta blockers or endoscopic therapy. For secondary prophylaxis, sclerotherapy or variceal band ligation is effective; there is scare evidence to recommend beta-blockers. Surgery shunt is indicated in children with variceal bleeding who fail endoscopic therapy and for symptomatic hypersplenism; spleno-renal or meso-ilio-cava shunting is the alternative when Mesorex bypass is not feasible due to anatomic problems or in centers with no experience.

CONCLUSIONS

Prospective control studies are required for a better knowledge of the natural history of EHPVO, etiology identification including prothrombotic states, efficacy of beta-blockers and comparison with endoscopic therapy on primary and secondary prophylaxis.

Portal hypertension in children: expert pediatric opinion on the report of the Baveno v Consensus Workshop on Methodology of Diagnosis and Therapy in Portal Hypertension

Complications of portal hypertension in children lead to significant morbidity and are a leading indication for consideration of liver transplantation. Approaches to the management of sequelae of portal hypertension are well described for adults and evidence-based approaches have been summarized in numerous meta-analyses and conferences. In contrast, there is a paucity of data to guide the management of complications of portal hypertension in children. An international panel of experts was convened on April 8, 2011 at The Children's Hospital of Pittsburgh of UPMC to review and adapt the recent report of the Baveno V Consensus Workshop on the Methodology of Diagnosis and Therapy in Portal Hypertension to the care of children. The opinions of that expert panel are reported.

Evaluation of cardiac manifestations in pediatric liver transplant candidates

Knowledge concerning the involvement of the cardiovascular system in children awaiting liver transplant is limited. Therefore, no guidelines have been established on evaluating this group of patients for cardiac disease. This review examines the diverse cardiovascular manifestations of liver disease in children. We also discuss the available testing and its applicability in screening for cardiac disease in this vulnerable population.

[Hepatopulmonary syndrome: a complication of type 1 Gaucher disease]

Gaucher's disease is a not exceptional lysosomial disease in Tunisia. Type 1 is by far the most common one. Pulmonary involvement is considered to be rare in type 1 Gaucher's disease. Pulmonary hypertension, infiltration of the lungs with Gaucher cells, and severe hypoxemia due to intrapulmonary arterial-venous shunts, have been described in case reports and small case series. We reported the case of hepatopulmonary syndrome in a 14-year-old boy with type 1 Gaucher disease. The diagnosis of Gaucher disease was established, at 2 years age, by enzyme assay of leucocyte β-glucosidase. The patient presented dyspnoea, digital clubbing and cyanosis of the lips. The arterial blood gas found severe hypoxaemia with PaO(2) at 56.9 mmHg. The diagnosis of hepatopulmonary syndrome, in our patient, was confirmed by demonstration of the intrapulmonary shunting using contrast-enhanced echocardiography and the technetium-99m-labeled macroaggregated albumin. The patient was treated by symptomatic measure, long term oxygen therapy because the insufficiency of the enzyme replacement therapy. Screening for hypoxemia in children with liver disease should be considered.

Hepatopulmonary syndrome in children with cirrhotic and non-cirrhotic portal hypertension: a single-center experience

BACKGROUND

Hepatopulmonary syndrome (HPS) is defined as an arterial oxygenation defect induced by intrapulmonary vascular dilatation (IPVD) associated with hepatic disease. The prevalence and clinical characteristics of HPS in portal hypertensive children is not well characterized.

AIMS

The aim of this study was to investigate the prevalence and clinical characteristics of HPS in 40 portal hypertensive children.

METHODS

We studied 40 children (11 girls and 29 boys; mean age, 111 months ± 52 months; range, 24-216 months) with portal hypertension (24 cirrhotic, 16 non-cirrhotic) for the presence of HPS using blood gas analysis, contrast-enhanced echocardiography (CEE), and Tc99m-macroaggregated albumin scintigraphy. Clinical and laboratory characteristics of patients were recorded. HPS was considered to be present in a patient with hypoxemia and/or an elevated alveolar-arterial oxygen gradient (PAaO(2)) ≥ 15 mmHg) and positive CEE and/or scintigraphy.

RESULTS

Elevated PAaO(2) was detected in 7 of 24 patients with cirrhosis. Four of them also had IPVD with CEE. An intrapulmonary shunt in Tc99m-MAA with CEE was shown in one patient. A diagnosis of HPS was made in 16.7% of the patients with cirrhosis. Cirrhotic patients without IPVD had significantly better hepatic function and lower pediatric end-stage liver disease scores. Although, 2 of the 16 patients with non-cirrhotic portal hypertension had elevated PAaO(2,) none of them showed IPVD. One normoxemic patient in the non-cirrhotic portal hypertension group showed IPVD with CEE. None of the non-cirrhotic patients fulfilled the diagnostic criteria of HPS.

CONCLUSION

Hepatopulmonary syndrome particularly occurs in cirrhotic portal hypertensive patients with severe hepatic dysfunction.

Nitric oxide for post-liver-transplantation hypoxemia in pediatric hepatopulmonary syndrome: case report and review

HPS is rare in the pediatric population. Liver transplantation is the ultimate treatment for severe HPS. There are only a few case reports and one series of children in whom HPS was the main indication for liver transplantation. Outcome was good in most of them, with full regression of the pulmonary process. However, hypoxemia in the early post-operative course can have severe consequences, and effective treatment modalities are needed. There are rare instances of the use of iNO for the treatment of post-operative hypoxemia. We describe a 10.5-yr-old boy with severe HPS owing to chronic liver disease after bone marrow transplantation. Liver transplantation from a living related donor (the same sister who donated the bone marrow) was complicated by severe hypoxemia on POD 2. iNO was administered via the ventilator circuit and, after extubation, through nasal prongs. It was slowly tapered down and stopped on POD 10. The child had an otherwise uneventful course and was discharged home on POD 21 with normal oxygen saturation. Liver transplantation should be offered to children with severe HPS. iNO can reverse the hypoxemia that may occur after the operation.