Onset ages of hepatopulmonary syndrome and pulmonary hypertension in patients with biliary atresia

HEPATOPULMONARY SYNDROME IN PEDIATRIC PATIENTS WITH PORTAL HYPERTENSION - AN INTEGRATIVE REVIEW

BACKGROUND

Hepatopulmonary syndrome (HPS) is characterized by the triad of abnormal arterial oxygenation caused by intrapulmonary vascular dilatations (IPVD) in the setting of advanced liver disease or portal hypertension, impacting the patient's quality of life and survival. There are still many gaps in the literature on this topic, especially in pediatrics, with practices frequently based on extrapolation of data obtained from adults.

OBJECTIVE

Provide a synthesis of the current knowledge about HPS in children.

METHODS

The research was carried out through narrative review. The databases used for the search include Medline, Embase, Elsevier, Lilacs and Scielo. The keywords used were "hepatopulmonary syndrome" AND child, children, infant, preschool, pediatric.

RESULTS

In cirrhotic children, the prevalence of HPS can reach up to 42.5%, and it is even more common in those whose underlying condition is biliary atresia, reaching up to 63%. Screening with pulse oximetry (O2 saturation <96%), unlike in adults, has low sensitivity in the pediatric age group. Management involves supportive care with oxygen therapy; liver transplantation is the only definitive treatment to reverse the condition and HPS is considered an exceptional criterion for waitlist. The waitlist mortality is similar among children listed by HPS as a special criterion when compared to those listed for other reasons. The reported rates of complete resolution of hypo-xemia after liver transplantation are close to 100% in children. The post-liver transplantation survival is similar or slightly lower in children with HPS when compared to those without HPS. Contrary to findings from adults, no differences were found in post- liver transplantation mortality between children of different hypoxemia ranges, although longer mechanical ventilation time and hospital stay were observed in children with PaO2 <50 mmHg.

CONCLUSION

HPS is not an uncommon complication of cirrhosis in children and adolescents, particularly when biliary atresia is the underlying condition. There are still many gaps to be filled regarding the condition, and this article demonstrates that not all data obtained in studies with adults reflects the disease's behavior in pediatrics, especially concerning prognosis.

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.

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.

Biliary Atresia/Neonatal Cholestasis: What is in the Horizon?

"Biliary atresia (BA) is a common cause of jaundice in infancy. There is increasing evidence that newborn screening with direct or conjugated bilirubin leads to earlier diagnosis. Although the Kasai portoenterostomy is the primary treatment, there are scientific advances in adjuvant therapies. As pediatric patients transition to adult care, multidisciplinary care is essential, given the complexity of this patient population."

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.

Transitional care of biliary atresia

Worldwide native liver survival (NLS) for young adults (>20 years) with biliary atresia varies between 14% and 44% with the majority of patients developing complications in adulthood. Cholangitis and portal hypertension with variceal bleeding are the most common complications and development of these during adolescence associated with the need for liver transplantation during adulthood. Adult listing criteria, typically developed on the background of adult liver disease might not be applicable to this patient population and leads to longer waiting time and risk of deterioration of their medical condition. Current data on growth and puberty in young people with biliary atresia surviving with native liver are rare. Pregnancy has been associated with serious complications in particular for those patients with advanced liver disease and, close follow up by specialist teams recommended. The long-term effect of having a chronic liver disease such as biliary atresia on neuro-cognitive and pubertal development has not been sufficiently explored to date despite reports of a high prevalence of additional educational needs in this cohort. In addition, patients and parents report inferior health related quality of life compared to healthy peers and similar to that of children post liver transplantation. Moving on from paediatric to adult services is challenging for young people and their parents and adult health professionals might not be familiar with the condition and complications. Young people deserve to be looked after by specialist, multidisciplinary services who provide holistic care and address their psychosocial needs in addition to the medical needs.

Five-year native liver survival analysis in biliary atresia from a single large Chinese center: The death/liver transplantation hazard change and the importance of rapid early clearance of jaundice

PURPOSE

This study aimed to analyze the change of death/liver transplantation hazard and biochemical indexes over time after Kasai procedure (KP) based on a retrospective biliary atresia (BA) cohort, and to evaluate the predictive value of early jaundice clearance rate to 5-year native liver survival (NLS).

METHODS

A retrospective cohort with follow-up results of 139 BA patients from January 2009 to December 2012 was established, and the pre- and postoperative data were collected. NLS rates were estimated with Kaplan-Meier curves, and any differences between groups were tested by log-rank test. Hazard curve of death/liver transplantation was fitted with Weibull distribution, and hazards at certain time points were calculated. Trend charts of biochemical indexes were drawn to show any changes over time. Rate of jaundice clearance was indicated as the proportion of decreased total bilirubin level at a certain postoperative time point to preoperative total bilirubin level. In multivariate analysis for prediction of 5-year NLS, COX proportional hazard regression model was used and results were expressed as hazard ratios with 95% confidence intervals (CIs). The predictive value of early jaundice clearance rates for 5-year NLS was analyzed by receiver operating characteristic (ROC) curve, and a cut-off value of 4-week jaundice clearance rate was determined.

RESULTS

The estimated 5-year NLS rate of the 139 patients was 58.0%. The patients had a high hazard of death/liver transplantation early after KP, which gradually decreased and stabilized at a lower level 1 year later. Most death/liver transplantation events occurred within 1 year after KP. The total bilirubin (TBIL), direct bilirubin (DBIL) and total bile acid (TBA) levels of successful Kasai group decreased continuously after KP, and the biggest decline was seen in the first month. The aspartate aminotransferase (AST), alanine aminotransferase (ALT) and γ-glutamyl transpeptidase (GGT) levels increased during the first month after KP and decreased continuously thereafter. All the biochemical indexes of successful Kasai group tended to stabilize within/close to normal range 1 year after KP. On the contrary, all the biochemical indexes of failed Kasai group fluctuated at obvious abnormal levels after KP. The estimated 5-year NLS rates of successful Kasai group and failed Kasai group were 90.1% and 10.7% (p = 0.000). The most significant clinical protective factor of 5-year NLS was 4-week jaundice clearance rate, revealed by COX proportional hazard regression model, and the HR was 0.089 (95%CI 0.018-0.432, p = 0.003). In predicting 5-year native liver survival, the largest area under ROC (AUROC) curve belonged to 4-week jaundice clearance rate, which was 0.731 (p = 0.000). A cut-off value of 0.457 was determined, with sensitivity 0.827, specificity 0.552, positive predictive value 0.720, and negative predictive value 0.696. NLS rates of patients divided by cut-off value showed significant statistical difference demonstrated by Kaplan-Meier curve and log-rank test (p = 0.000).

CONCLUSIONS

The 5-year death/liver transplantation hazard of biliary atresia patients reduces greatly and stabilizes 1 year after KP. A successful KP enables patients to achieve long-term stable normal biochemical indexes. A rapid clearance of jaundice is of great positive significance to 5-year NLS, and the 4-week jaundice clearance rate is of some predictive value.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level II, retrospective study.