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

A Retransplant Case for Hepatopulmonary Syndrome Without Liver Cirrhosis or Portosystemic Shunt After Living-Donor Liver Transplantation: A Case Report

Hepatopulmonary syndrome (HPS) is a disease of gas exchange caused by intrapulmonary shunting secondary to liver disease-associated intrapulmonary vascular dilation. HPS is characterized by the triad of cirrhosis, chronic liver disease, or portosystemic shunting (PSS); arterial hypoxemia; and intrapulmonary arteriovenous shunting in the absence of a primary cardiopulmonary anomaly. We encountered a rare case of HPS without liver disease or PSS. The patient was an 8-year-old girl who underwent living donor liver transplantation (LDLT) shortly after developing fulminant hepatitis at 11 months of her age. Eight years after LDLT, hypoxemia and shortness of breath developed. The shunt ratio on ^99mTc-macroaggregated albumin (MAA) lung perfusion scintigraphy (^99mTc-MAA lung scan) was 32%. The patient had no cardiopulmonary disease, so we diagnosed her illness as HPS. We did not find cirrhosis, chronic liver disease, or PSS as a cause of HPS. We thought the graft was the cause of HPS. A second transplantation was planned. One year after the diagnosis of HPS, the shunt ratio on ^99mTc-MAA lung scan worsened to 42%, digital clubbing appeared, and hypoxemia was worsening. Thus, we performed a second LDLT. After LDLT the shunt ratio on ^99mTc-MAA lung scan normalized (6%) and cyanosis resolved. We determined that the graft was the cause of HPS; the typical causes of HPS were not clearly revealed in the histologic examination of the second liver explant. Acute rejection occurred twice after LDLT, so we speculated that HPS occurred because the graft became stressed over the long term.

Impact of hypoxemia on pediatric liver transplantation for hepatopulmonary syndrome

BACKGROUND

The treatment of choice for patients with cirrhosis and HPS is LT. The clinical manifestations associated with hypoxemia result in limitations and a poor health-related quality of life of affected patients. The present report aims to study the differences in outcomes between patients with PaO₂  < 50 mm Hg and those with PaO₂  ≥ 50 mm Hg.

METHODS

This was a retrospective study of 21 patients under 18 years of age conducted from 2001 to 2018; the patients were divided into 2 groups: G1-PaO₂  ≥ 50 mm Hg, 11 patients, and G2-PaO₂  < 50 mm Hg, 10 patients. Demographic, clinical, laboratory, and perioperative data; outcome variables; and post-transplant survival were compared between the groups.

RESULTS

In total, 2/11 (18.2%) patients in G1 and 8/10 (80%) patients in G2 required supplemental oxygen therapy at home (P = .005). Patients in G2 required prolonged MV (median 8.5 days in G2 vs 1 day in G1, P = .015) and prolonged ICU and hospital stays (P = .002 and P = .001, respectively). Oxygen weaning time was longer in G2 (median 127.5 days) than in G1 (median 3 days; P = .004). One (9.1%) patient in G1 and three (30%) patients in G2 died (P = .22). The survival at 90 months was 90.9% in G1 and 70% in G2 (P = .22).

CONCLUSION

The survival between groups was similar. Patients with very severe HPS required a longer MV time, longer ICU and hospital stays, and a longer O₂ weaning time than those with mild, moderate, or severe HPS.

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.

The efficacy of serum brain natriuretic peptide for the early detection of portopulmonary hypertension in biliary atresia patients before liver transplantation

Severe portopulmonary hypertension (POPH) is a contraindication for liver transplantation (LT) because of the high risk of postoperative heart failure. The early detection of POPH is important for patients with biliary atresia (BA). Brain natriuretic peptide (BNP) is known to be correlated with liver fibrosis in patients with liver cirrhosis. The aim of this study was to elucidate the efficacy of BNP measurement for the follow-up of patients with BA. Thirty-two patients with BA were identified from September 2011 to December 2016. As indices of liver fibrosis/cirrhosis, APRI (P < .0001), FIB-4 (P < .0001), Child-Pugh score (P < .0001), IV collagen (P = .0005), and hyaluronic acid (P = .0291) had high or moderate correlations with BNP. Patients with splenomegaly, esophageal varices, liver fibrosis, and collateral veins had significantly higher BNP levels than those without. Patients diagnosed with POPH had significantly higher BNP levels in comparison with those patients without (P = .0068). In contrast, PELD/MELD scores showed an almost negligible correlation with the BNP level. LT was successful in 3 asymptomatic BA patients with POPH who had high BNP levels despite the low PELD/MELD scores. In conclusion, routine serum BNP surveillance can be easy to predict asymptomatic POPH. This may help to identify POPH before it reaches a stage that would contraindicate LT.

The early outcomes of candidates with portopulmonary hypertension after liver transplantation

Background

Portopulmonary hypertension (PPH) was once regarded as a contraindicaton to liver transplantation (LT). However, growing evidence has indicated that PPH patients undergoing LT may show similar outcomes compared to those without PPH, and researchers have recommended it not be an absolute contraindication. Given this controversy, we aimed to identify and review the current evidence on this topic and to provide a comparison of the outcomes after LT between candidates with PPH and those without.

Methods

We systematically searched the MEDLINE, EMBASE and Cochrane Library databases for all studies that compared the outcomes of PPH patients and those without PPH after LT. All studies reporting outcomes of PPH patients versus those without PPH (Control) were further considered for inclusion in this meta-analysis. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to compare the pooled data between PPH and Control groups.

Results

Eleven retrospective trials and one prospective, randomized, controlled trial, involving 37,686 transplant recipients were included. The PPH patients had increased 1-year mortality with an OR of 1.59 (95% CI = 1.26–2.01, P = 0.0001) compared to the control group. There was no significant difference in graft loss and 30-day mortality after LT between the two groups.

Conclusions

Patients with PPH who underwent LT had increased 1-year mortality compared to those without PPH, while graft loss and 30-day mortality were similar. Nevertheless, LT may be a reasonable therapeutic option for some patients with PPH, but further studies are needed to identify those select patients with PPH who would benefit most from LT.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0797-8) contains supplementary material, which is available to authorized users.

Portopulmonary hypertension in children: a rare but potentially lethal and under-recognized disease

Portopulmonary hypertension (PoPH) is defined by the combination of portal hypertension and precapillary pulmonary arterial hypertension (PAH). Very little is known about this process in pediatric patients but prognosis is generally poor. We review our institutional experience and report on five patients with pediatric PoPH. The median age of PoPH diagnosis was six years and PAH was 14 years. PAH diagnosis was made by echocardiogram in all patients, four of whom also had cardiac catheterization. The median mean pulmonary artery pressure (mPAP) was 48.5 mmHg (interquartile range [IQR] = 46–60) with a median pulmonary vascular resistance index (PVRi) of 9 WU*M² (IQR = 8–22). All were acute pulmonary vasodilator testing non-responsive. All patients received targeted therapies. Three of five patients (60%) died despite an evidence-based approach to care. Of those who died, timing from the PoPH diagnosis to death ranged from three days to three years. Based upon our limited experience, PoPH is a disorder with significant mortality in childhood and challenges in treatment. Future research, focused on screening and early targeted treatment strategies, may alter the current dismal prognosis for these children.

International Liver Transplant Society Practice Guidelines: Diagnosis and Management of Hepatopulmonary Syndrome and Portopulmonary Hypertension

Two distinct pulmonary vascular disorders, hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) may occur as a consequence of hepatic parenchymal or vascular abnormalities. HPS and POPH have major clinical implications for liver transplantation. A European Respiratory Society Task Force on Pulmonary-Hepatic Disorders convened in 2002 to standardize the diagnosis and guide management of these disorders. These International Liver Transplant Society diagnostic and management guidelines are based on that task force consensus and should continue to evolve as clinical experience dictates. Based on a review of over 1000 published HPS and POPH articles identified via a MEDLINE search (1985-2015), clinical guidelines were based on, selected single care reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Guidelines are presented in 5 parts; I. Definitions/Diagnostic criteria; II. Hepatopulmonary syndrome; III. Portopulmonary hypertension; IV. Implications for liver transplantation; and V. Suggestions for future clinical research.

Hepatopulmonary syndrome is a frequent cause of dyspnea in the short telomere disorders

BACKGROUND

Telomere syndromes have their most common manifestation in idiopathic pulmonary fibrosis and emphysema. The short telomere defect in these patients may manifest systemically as bone marrow failure and liver disease. We sought to understand the causes of dyspnea in telomerase and telomere gene mutation carriers who have no parenchymal lung disease.

METHODS

Clinical and pathologic data were reviewed as part of a Johns Hopkins-based natural history study of short telomere syndromes including dyskeratosis congenita.

RESULTS

Hepatopulmonary syndrome (HPS) was diagnosed in nine of 42 cases (21%). Their age at presentation was significantly younger than that of cases initially presenting with pulmonary fibrosis and emphysema (median, 25 years vs 55 years; P < .001). Cases had evidence of intra- and extrapulmonary arteriovascular malformations that caused shunt physiology. Nodular regenerative hyperplasia was the most frequent histopathologic abnormality, and it was seen in the absence of cirrhosis. Dyspnea and portal hypertension were progressive, and the median time to death or liver transplantation was 6 years (range, 4-10 years; n = 6). In cases that underwent liver transplantation, dyspnea and hypoxia improved, but pulmonary fibrosis subsequently developed.

CONCLUSIONS

This report identifies HPS as a frequent cause of dyspnea in telomerase and telomere gene mutation carriers. While it usually precedes the development of parenchymal lung disease, HPS may also co-occur with pulmonary fibrosis and emphysema. Recognizing this genetic diagnosis is critical for management, especially in the lung and liver transplantation setting.

Portopulmonary Hypertension in Liver Disease Presenting in Childhood

OBJECTIVE

Portopulmonary hypertension (POPH) is a known complication of cirrhosis in adults, but there is little information on its incidence and outcome in children with liver disease. We report 14 patients with POPH and present a synthesis of the medical literature.

METHODS

Diagnosis of POPH in the 14 patients was based on right-sided heart catheterization displaying mean pulmonary artery pressure (mPAP) >25 mmHg, indexed pulmonary vascular resistances >3 Wood units · m, and pulmonary wedge pressure <15 mmHg. A literature review added 84 patients.

RESULTS

In our unit, POPH was found in 0.5% of the children with portal hypertension, 0.9% of the children with end-stage liver disease awaiting transplantation, and 3 children with congenital portosystemic shunts (CPSSs). Analysis of 98 reported patients, including the 14 presented here, showed the cause of liver disease to be chronic liver disease or portal cavernoma in 76 instances (34 with a history of surgical portosystemic shunt) and CPSS in 22 instances. There was a precession with proven hypoxemia caused by hepatopulmonary syndrome in 6 patients. Median survival was 3 months in 56 untreated patients. An 80% 5-year probability of survival in 42 patients was treated by CPSS closure, pulmonary vasodilators, and/or liver transplantation. Mean pretransplant mPAP was 34 and 49 mmHg in transplant survivors and nonsurvivors, respectively.

CONCLUSIONS

POPH is a rare but extremely severe complication of childhood liver disease. Portosystemic shunts, whether congenital or acquired, likely play an important causative role. Early diagnosis is crucial and requires systematic screening by echocardiography in children at risk.

Extracorporeal Membrane Oxygenation and Severe Portopulmonary Hypertension following Liver Transplantation: Brief Report

Background

Patients with severe portopulmonary hypertension (PoPH) responsive to medical therapy may be considered for liver transplantation. We present a case of extracorporeal membrane oxygenation (ECMO) resuscitation for PoPH crisis in a child following liver transplantation (LT), and review the literature on management of this challenging setting.

Case report

A 7-year-old girl, with previous Kasai portoenterostomy and subsequent severe PoPH responsive to pulmonary vasodilator therapy, underwent orthotopic LT. Five days following surgery, she had an asystolic arrest with suprasystemic pulmonary hypertension, and was resuscitated with ECMO therapy. Multi-modal strategies included sildenafil, ambrisentan, nitric oxide, intravenous Epoprostenol infusion, levosimendan, and atrial septostomy. Ten days after her LT, exploration for bleeding was necessary following abdominal drain removal. By 10 days of ECMO support, she was reviewed and considered for lung transplantation. Unfortunately, she deteriorated precipitously with abdominal compartment syndrome and multi-organ failure; sadly, life support was withdrawn 23 days after transplantation.

Discussion

Patients with severe PoPH may need combined thoracic organ and liver transplantation either at single or serial events. Case reports on ECMO use include resuscitation after massive pulmonary embolism during liver transplantation, bridge until the goal of vasodilatory therapy was reached in worsening PoPH following LT, and bridge to lung or repeat liver transplantation for severe pulmonary hypertension.

Conclusions

ECMO resuscitation and support may be deployed as rescue therapy around the period of liver transplantation. We highlight the importance of patient selection and high risk of complications during ECMO therapy as a bridge to PoPH control.

Use of airway pressure release ventilation in a child with refractory hepatopulmonary syndrome after liver transplantation

HPS is a life-threatening condition in patients with end-stage liver disease, in which intrapulmonary vascular dilatations result in intrapulmonary shunts and hypoxemia. The only successful treatment is liver transplantation. Hypoxemia may be severe prior to transplantation; however, it can worsen or become refractory after liver transplantation and result in increased post-operative mortality. Here, we present the case of a 10-month-old female infant with progressive end-stage liver disease and severe HPS, who developed refractory hypoxemia after a successful liver transplantation. After 19 days of unsuccessful attempts to reverse the hypoxemia using conventional mechanical ventilation and HFOV, the patient responded dramatically to APRV, with rapid improvement in her PaO2 and sharp decline in her OI. She was able to begin weaning from APRV two days later and was extubated within seven days. APRV was successful in treating refractory hypoxemia in this patient with severe HPS after liver transplantation, possibly by modifying distribution of pulmonary blood flow. Although we cannot rule out coincidental natural resolution of the HPS, APRV could be a useful rescue therapy in patients with HPS and refractory hypoxemia.

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.

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.

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.

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.

Pulmonary vascular complications of chronic liver disease: Pathophysiology, imaging, and treatment

To review the pathogenesis of pulmonary vascular complications of liver disease, we discuss their clinical implications, and therapeutic considerations, with emphasis on potential reversibility of the hepatopulmonary syndrome after liver transplantation. In this review, we also discuss the role of imaging in pulmonary vascular complications associated with liver disease.

A consensus approach to the classification of pediatric pulmonary hypertensive vascular disease: Report from the PVRI Pediatric Taskforce, Panama 2011

Current classifications of pulmonary hypertension have contributed a great deal to our understanding of pulmonary vascular disease, facilitated drug trials, and improved our understanding of congenital heart disease in adult survivors. However, these classifications are not applicable readily to pediatric disease. The classification system that we propose is based firmly in clinical practice. The specific aims of this new system are to improve diagnostic strategies, to promote appropriate clinical investigation, to improve our understanding of disease pathogenesis, physiology and epidemiology, and to guide the development of human disease models in laboratory and animal studies. It should be also an educational resource. We emphasize the concepts of perinatal maladaptation, maldevelopment and pulmonary hypoplasia as causative factors in pediatric pulmonary hypertension. We highlight the importance of genetic, chromosomal and multiple congenital malformation syndromes in the presentation of pediatric pulmonary hypertension. We divide pediatric pulmonary hypertensive vascular disease into 10 broad categories.

Hepatic failure, neonatal hemochromatosis and porto-pulmonary hypertension in a newborn with trisomy 21--a case report

Liver failure in neonates is a rare but often fatal disease. Trisomy 21 is not usually associated with significant infantile liver disease. If present, hepatic dysfunction in an infant with Trisomy 21 is likely to be attributed to transient myeloproliferative disorder with hepatic infiltration by hematopoietic elements and may be associated with secondary hemosiderosis. A less commonly recognized cause of liver failure in neonates with Trisomy 21 is neonatal hemochromatosis (NH); this association has been reported in nine cases of Trisomy 21 in literature. NH is a rare, severe liver disease of intra-uterine onset that is characterized by neonatal liver failure and hepatic and extrahepatic iron accumulation that spares the reticuloendothelial system. NH is the most frequently recognized cause of liver failure in neonates and the commonest indication for neonatal liver transplantation. Although porto-pulmonary hypertension (PPH) has been reported as a complication of liver failure in adults and older children, this has not been reported in neonates with liver failure of any etiology. This is probably due to the rarity of liver failure in newborns, delayed diagnosis and high mortality. The importance of recognizing PPH is that it is reversible with liver transplantation but at the same time increases the risk of post-operative mortality. Therefore, early diagnosis of PPH is critical so that early intervention can improve the chances of successful liver transplantation. We report for the first time the association of liver failure with porto-pulmonary hypertension secondary to NH in an infant with Trisomy 21.

Non-congenital heart disease associated pediatric pulmonary arterial hypertension

Recognition of causes of pulmonary hypertension other than congenital heart disease is increasing in children. Diagnosis and treatment of any underlying cause of pulmonary hypertension is crucial for optimal management of pulmonary hypertension. This article discusses the available knowledge regarding several disorders associated with pulmonary hypertension in children: idiopathic pulmonary arterial hypertension (IPAH), pulmonary capillary hemangiomatosis, pulmonary veno-occlusive disease, hemoglobinopathies, hepatopulmonary syndrome, portopulmonary hypertension and HIV. Three classes of drugs have been extensively studied for the treatment of IPAH in adults: prostanoids (epoprostenol, treprostinil, iloprost, beraprost), endothelin receptor antagonists (bosentan, sitaxsentan, ambrisentan), and phosphodiesterase inhibitors (Sildenafil, tadalafil). These medications have been used in treatment of children with pulmonary arterial hypertension, although randomized clinical trial data is lacking. As pulmonary vasodilator therapy in certain diseases may be associated with adverse outcomes, further study of these medications is needed before widespread use is encouraged.