Elizabeth B. Rand

The precarious state of the liver after a Fontan operation: summary of a multidisciplinary symposium.

As the cohort of survivors with the single-ventricle type of congenital heart disease grows, it becomes increasingly evident that the state of chronically elevated venous pressure and decreased cardiac output inherent in the Fontan circulation provides the substrate for a progressive decline in functional status. One organ at great risk is the liver. Wedged between two capillary beds, with the pulmonary venous bed downstream, which typically has no pulsatile energy added in the absence of a functional right ventricle, and the splanchnic bed upstream, which may have compromised inflow due to inherent cardiac output restriction characteristic of the Fontan circulation, the liver exists in a precarious state. This review summarizes a consensus view achieved at a multidisciplinary symposium held at The Children’s Hospital of Philadelphia in June 2011. The discussion includes current knowledge concerning the hemodynamic foundations of liver problems, the diagnostic tools available, the unique histopathology of the liver after the Fontan operation, and proposed mechanisms for hepatic fibrosis at the cellular level. At the completion of the symposium, a consensus recommendation was made by the authors’ group to pursue a new prospective protocol for clinical evaluation of the liver for all patients in our practice 10xa0years after the Fontan operation.

Hepatic pathology may develop before the Fontan operation in children with functional single ventricle: An autopsy study

OBJECTIVEnLiver fibrosis has emerged as an important long-term complication of the Fontan operation. We aimed to describe liver histology at autopsy in patients who had undergone the Fontan operation and to determine whether patient variables are associated with the degree of fibrosis.nnnMETHODSnA review was performed of all patients with a history of the Fontan operation who died and underwent autopsy at our institution from 1980 to 2009. Autopsy liver slides were evaluated independently by 2 pathologists.nnnRESULTSnTwenty-two patients were studied. The median interval between Fontan and death was 20 days (range, 1 day-17.5 years). Portal fibrosis was observed in 20 (91%) patients and sinusoidal fibrosis was observed in 17 (77%) patients. Using simple linear regression, time from the Fontan operation was significantly associated with the degree of portal fibrosis on Ishak (P = .03) and modified Scheuer fibrosis (P = .02) scales. Significant portal fibrosis was observed in 8 (57%) of the 14 patients who died 30 days or less after the Fontan operation. In these 14 patients, severity of portal fibrosis was associated with length of hospitalization after pre-Fontan cardiac operations (P = .03) and pre-Fontan mean right atrial pressure (P = .04).nnnCONCLUSIONSnAt autopsy, hepatic fibrosis was commonly observed in patients who had undergone the Fontan operation. Portal fibrosis has been previously unrecognized in this population. Significant portal fibrosis occurred in most who died soon after the Fontan procedure and was associated with pre-Fontan morbidity. Hepatic disease in the single-ventricle population is multifactorial and may begin before the Fontan operation.

Intravenous N-acetylcysteine in pediatric patients with nonacetaminophen acute liver failure: A placebo-controlled clinical trial

N‐acetylcysteine (NAC) was found to improve transplantation‐free survival in only those adults with nonacetaminophen (non‐APAP) acute liver failure (ALF) and grade 1‐2 hepatic encephalopathy (HE). Because non‐APAP ALF differs significantly between children and adults, the Pediatric Acute Liver Failure (PALF) Study Group evaluated NAC in non‐APAP PALF. Children from birth through age 17 years with non‐APAP ALF enrolled in the PALF registry were eligible to enter an adaptively allocated, doubly masked, placebo‐controlled trial using a continuous intravenous infusion of NAC (150 mg/kg/day in 5% dextrose in water [D5W]) or placebo (D5W) for up to 7 days. The primary outcome was 1‐year survival. Secondary outcomes included liver transplantation‐free survival, liver transplantation (LTx), length of intensive care unit (ICU) and hospital stays, organ system failure, and maximum HE score. A total of 184 participants were enrolled in the trial with 92 in each arm. The 1‐year survival did not differ significantly (P = 0.19) between the NAC (73%) and placebo (82%) treatment groups. The 1‐year LTx‐free survival was significantly lower (P = 0.03) in those who received NAC (35%) than those who received placebo (53%), particularly, but not significantly so, among those less than 2 years old with HE grade 0‐1 (NAC 25%; placebo 60%; P = 0.0493). There were no significant differences between treatment arms for hospital or ICU length of stay, organ systems failing, or highest recorded grade of HE. Conclusion: NAC did not improve 1‐year survival in non‐APAP PALF. One‐year LTx‐free survival was significantly lower with NAC, particularly among those <2 years old. These results do not support broad use of NAC in non‐APAP PALF and emphasizes the importance of conducting controlled pediatric drug trials, regardless of results in adults. (HEPATOLOGY 2013)

Portal and Sinusoidal Fibrosis are Common on Liver Biopsy After Fontan Surgery

Hepatic fibrosis is an important complication after Fontan surgery in patients with single-ventricle congenital heart disease. Few reports of hepatic histology in these patients exist, and sinusoidal fibrosis has been described. We aimed to characterize fibrosis at liver biopsy procedure in patients with previous Fontan surgery and to identify patient variables associated with the degree of fibrosis. All patients who had previous Fontan surgery and who subsequently underwent liver biopsy at our institution between January 1990 and July 2010 were identified. For each biopsy specimen, portal and sinusoidal fibrosis were graded and medical records reviewed. Biopsy specimens from 13 patients were examined; the median time from Fontan surgery to liver biopsy procedure was 16.9xa0years (range 6.9–25). At the most recent biopsy procedure, 12 patients (92xa0%) had evidence of portal fibrosis, including 1 patient with portal-based cirrhosis. Thirteen patients (100xa0%) had at least some degree of sinusoidal fibrosis, including 1 patient with centrilobular-based cirrhosis. Lower platelet count was associated with greater degree of portal fibrosis by ordinal regression (odds ratio 0.84, Pxa0=xa00.04), and patients with no or mild portal fibrosis had significantly higher platelet counts compared with those with moderate or severe portal disease (278xa0±xa078xa0K vs. 160xa0±xa046xa0K, Pxa0=xa00.005). Four patients underwent serial biopsy procedures; portal fibrosis was progressed in 3 patients, and sinusoidal fibrosis was progressed in 3 patients. After Fontan surgery, portal and sinusoidal fibrosis are common at liver biopsy and can progress over time. Lower platelet count may represent a marker of portal-based disease in these patients.

Differing Effects of Rapamycin or Calcineurin Inhibitor on T‐Regulatory Cells in Pediatric Liver and Kidney Transplant Recipients

In a cross‐sectional study, we assessed effects of calcineurin inhibitor (CNI) or rapamycin on T‐regulatory (Treg) cells from children with stable liver (n = 53) or kidney (n = 9) allografts several years posttransplant. We analyzed Treg number, phenotype, suppressive function, and methylation at the Treg‐specific demethylation region (TSDR) using Tregs and peripheral blood mononuclear cells. Forty‐eight patients received CNI (39 as monotherapy) and 12 patients received rapamycin (9 as monotherapy). Treg numbers diminished over time on either regimen, but reached significance only with CNI (r =−0.424, p = 0.017). CNI levels inversely correlated with Treg number (r =−0.371, p = 0.026), and positively correlated with CD127+ expression by Tregs (r = 0.437, p = 0.023). Patients with CNI levels >3.6 ng/mL had weaker Treg function than those with levels <3.6 ng/mL, whereas rapamycin therapy positively correlated with Treg numbers (r = 0.628, p = 0.029) and their expression of CTLA4 (r = 0.726, p = 0.041). Overall, CTLA4 expression, TSDR demethylation and an absence of CD127 were important for Treg suppressive function. We conclude that rapamycin has beneficial effects on Treg biology, whereas long‐term and high dose CNI use may impair Treg number, function and phenotype, potentially acting as a barrier to attaining host hyporesponsiveness to an allograft.

Liver transplantation in patients with cystic fibrosis: Analysis of united network for organ sharing data

The improved life expectancy of patients with cystic fibrosis (CF) has led to a change in the impact of liver disease on the prognosis of this population. Liver transplantation has emerged as the procedure of choice for patients with CF and features of hepatic decompensation and for intractable variceal bleeding as a major manifestation. We retrospectively reviewed the United Network for Organ Sharing database to analyze the outcomes of 55 adults and 148 children with CF who underwent liver transplantation, and we compared them to patients who underwent transplantation for other etiologies. We additionally compared the benefits of liver transplantation among patients who underwent transplantation for cystic fibrosis–related liver disease (CFLD) and those who remained on the waiting list. The 5‐year survival rates for children and adults undergoing liver transplantation were 85.8% and 72.7%, respectively (P = 0.016). A multivariate Cox regression analysis comparing pediatric and adult CF patients to patients who underwent transplantation for other etiologies noted lower 5‐year survival rates (P < 0.0001). However, compared to those remaining on the waiting list, pediatric transplant recipients with CF (hazard ratio = 0.33, 95% confidence interval = 0.16‐0.70, P = 0.004) and adult transplant recipients with CF (hazard ratio = 0.25, 95% confidence interval = 0.11‐0.57, P = 0.001) gained a significant survival benefit. In conclusion, long‐term outcomes in patients with CFLD are acceptable but are inferior in comparison with the outcomes of those undergoing transplantation for other etiologies. Despite such observations, a survival benefit was noted in transplant patients versus those who remained on the waiting list. Liver Transpl, 2011.

Genomic alterations in biliary atresia suggest region of potential disease susceptibility in 2q37.3.

Biliary atresia (BA) is a progressive, idiopathic obliteration of the extrahepatic biliary system occurring exclusively in the neonatal period. It is the most common disease leading to liver transplantation in children. The etiology of BA is unknown, although infectious, immune and genetic causes have been suggested. Although the recurrence of BA in families is not common, there are more than 30 multiplex families reported and an underlying genetic susceptibility has been hypothesized. We screened a cohort of 35 BA patients for genomic alterations that might confer susceptibility to BA. DNA was genotyped on the Illumina Human Hap 550 Beadchip platform, which analyzes over 550,000 single nucleotide polymorphisms (SNPs) for genomic deletions and duplications. Areas of increased and decreased copy number were compared to those found in control populations. To identify regions that could serve as susceptibility factors for BA, we searched for regions that were found in BA patients, but not in controls. We identified two unrelated BA patients with overlapping heterozygous deletions of 2q37.3. Patient 1 had a 1.76u2009Mb (280 SNP), heterozygous deletion containing 30 genes. Patient 2 had a 5.87u2009Mb (1,346 SNP) heterozygous deletion containing 55 genes. The overlapping 1.76u2009Mb deletion on chromosome 2q37.3 from 240,936,900 to 242,692,820 constitutes the critical region and the genes within this region could be candidates for susceptibility to BA.

Effect of Kasai procedure on hepatic outcome in Alagille syndrome.

Objectives: Alagille syndrome (AGS) frequently presents with neonatal jaundice and can mimic other causes of high γ-glutamyl transpeptidase (GGT) cholestasis, most notably biliary atresia. As a result infants with AGS may undergo intraoperative cholangiogram and even Kasai procedure. The aim of the study was to assess the hepatic outcomes of children with AGS who underwent the Kasai procedure. Patients and Methods: A retrospective review of the AGS clinical database at the Childrens Hospital of Philadelphia was performed to identify clinically defined patients with AGS who underwent a Kasai. A cohort of Alagille control subjects was selected with equivalent symptoms of neonatal jaundice and matched for age and presence of cardiac anomaly. JAGGED1-mutation analysis was performed on available samples. Clinical courses were reviewed. Fisher exact and t tests were used for analysis. Results: Of the 430 patients with AGS, 19 underwent a Kasai procedure (K). The control cohort (C) consisted of 36 patients. Total bilirubin measured between 6 and 10 weeks of age in each cohort was equivalent (K: 9.6 mg/dL, C: 8.7 mg/dL); GGT levels were higher in the control group (K:493.4 U/L, C:574.4 U/L). Of note, the Kasai cohort had a significantly larger number of liver transplants (K: 9 [47.3%], C: 5 [13.9%], P = 0.01) and sustained higher mortality (K: 6 [31.6%], C: 1 [2.8%], P = 0.005). There was no genotype-phenotype correlation between the mutations identified and patients who underwent Kasai. Conclusions: These data suggest that the Kasai procedure, although appropriate for children with biliary atresia, does not benefit children with AGS and actually appears to worsen outcome. The current data suggest that the Kasai is not a marker for underlying severe liver disease, but the procedure itself may have a detrimental effect on outcome. An appropriate medical evaluation and particular consideration of AGS is essential before surgical referral in infants with high GGT cholestasis.

Risk Factors for End-Stage Kidney Disease After Pediatric Liver Transplantation

Adult liver transplant (LT) recipients commonly develop advanced kidney disease. However, burden of end‐stage kidney disease (ESKD) after pediatric LT has not been well‐described. We performed a retrospective cohort study of pediatric LTs in the United States from 1990 to 2010. Multivariable Cox regression models were fit to determine risk factors for ESKD and death. Eight thousand nine hundred seventy six children received LTs. During median follow‐up of 7.8 years, 2005 (22%) subjects died (mortality rate 26.1 cases/1000 person‐years); 167 (2%) developed ESKD (incidence rate 2.2 cases/1000 person‐years). Risk factors for ESKD included older age at LT (highest risk age >15 vs. < 5 years, HR = 4.94, p < 0.001), hepatitis C (HR 2.79, p = 0.004), liver re‐transplant (HR 2.67, p < 0.001), eGFR pre‐LT < 60 versus ≥ 60 (HR 2.37, p < 0.001), hepatitis B (HR 2.25, p = 0.027), black race (HR 1.46, p = 0.046), and male sex (HR 1.44, p = 0.022). LT recipients with ESKD had increased risk of mortality (HR 2.37, p < 0.001). Among pediatric LT recipients, rate of ESKD was lower than among adults and far exceeded by rate of death, however follow‐up time in this study may underestimate lifetime burden of ESKD. Although uncommon, ESKD was highly associated with mortality. Pediatric LT recipients should be routinely monitored for kidney disease, particularly those at highest risk of ESKD.

Fontan-Associated Liver Disease: Proceedings from the American College of Cardiology Stakeholders Meeting, October 1 to 2, 2015, Washington DC

Over the past decade, as the majority of patients with single ventricle anatomy who have undergone the Fontan operation reach adulthood, a newly recognized disease process, Fontan-associated liver disease (FALD), has emerged. FALD is an extracardiac complication that may lead to substantial comorbid disease and premature mortality. The risk factors, pathophysiology, longitudinal consequences, and therapeutic options related to FALD remain poorly defined. Although we recognize that Fontan circulatory properties are associated with extracardiac organ dysfunction, numerous gaps in our understanding of the nature of this relationship exist. Such extracardiac manifestations, in addition to other late complications of the circulation, can significantly affect quality of life and healthcare use. Therefore, to initiate a formal evaluation of FALD, the American College of Cardiology (ACC) sponsored a stakeholders meeting on October 1 to 2, 2015, in Washington, DC. The goal of the meeting was to bring together subspecialty experts in the fields of adult and pediatric hepatology, congenital cardiology (adult congenital and pediatric cardiology), heart failure/transplant, epidemiology, and cardiothoracic surgery, as well as patient advocates, patients, parents of children and young adults who have had the Fontan procedure, and research organizations and societies to discuss the current state of FALD. Topics included gaps in knowledge, optimal care, research opportunities and barriers, and sound practices to guide providers, patients, and families. This report summarizes findings from the stakeholders meeting and seeks to establish a platform for understanding and addressing FALD.