Intraoperative renal replacement therapy during liver transplantation in children: Safety, efficacy and impact on survival.

BACKGROUND: Intraoperative Continuous Renal Replacement Therapy (iCRRT) can prevent life-threatening complications, facilitate fluid management, and maintain metabolic homeostasis during liver transplantation (LT) in adults. There is a paucity of data in pediatric LT. We evaluated the safety, efficacy, and impact on survival of iCRRT in pediatric LT. METHODS: We conducted a retrospective cohort study of all children requiring CRRT pre-OLT at a quaternary children's hospital from 2014 to 2022. Demographic characteristics, intraoperative events, and post-LT outcomes were compared between those who received iCRRT and those who did not. RESULTS: Out of 306 patients who received LT, 30 (10%) were supported with CRRT at least 24 h prior to LT, of which 11 (36%) received iCRRT. The two cohorts were similar in demographics, diagnosis of liver disease, and severity of illness. The iCRRT patients experienced massive blood loss and increased transfusion requirements. There was no difference in intraoperative metabolic balance. One-year post-LT mortality rates were similar. CONCLUSION: ICRRT is safe in critically ill children with pre-LT renal dysfunction. It optimizes fluid and blood product resuscitation while maintaining metabolic homeostasis. Candidates need to be carefully chosen for this highly resource-intensive therapy to benefit this fragile population.

Pediatric Acute Liver Failure Secondary to Autoimmune Hepatitis in an Infant With Thrombocytopenia-Absent Radius (TAR) Syndrome: A Case Report.

Thrombocytopenia absent radius (TAR) syndrome is a rare genetic disorder that has been associated with food protein-induced allergic proctocolitis and transient leukemoid reactions, among other manifestations. There has been no prior reports of its association with autoimmune disease, more specifically, autoimmune hepatitis (AIH) or the development of pediatric acute liver failure (PALF). We present a case of an 8-month-old infant with TAR syndrome who presented with PALF, secondary to AIH with elevated liver-kidney microsomal antibody (>1:2560). She received a liver transplant and had a very complicated postoperative course including severe T-cell-mediated rejection, infection, biliary stricture, persistently elevated liver-kidney microsomal antibodies, and antibody-mediated rejection. Ultimately, these complications led to graft failure, severe sepsis, and death. This case highlights a new association of TAR syndrome with AIH and PALF and a potentially aggressive nature of AIH both pre- and post-transplant.

Development of a national Zoom-based lectureship for pediatric transplant hepatology trainees.

BACKGROUND: Previous publications identified a gap in standard education on topics related to advanced hepatology and liver transplantation for pediatric transplant hepatology trainees. The Society of Pediatric Liver Transplantation (SPLIT) Education Committee designed a Zoom-based lectureship series for all advanced pediatric transplant hepatology trainees. We aim to describe the educational series and feedback from fellow participants. METHODS: Pediatric transplant hepatology trainees from across the United States and Canada were invited to attend 25 Zoom-based lectures on a broad list of topics pertaining to pediatric transplant hepatology. At the completion of the lectureship, a 53-item REDcap survey using single-answer, Likert-scale, and open-ended questions was distributed via email to all participants. RESULTS: A total of 16 fellows from broad geographic areas responded to the survey. Nineteen percent (n = 3/16) of fellows attended all 25 lectures and 31% (n = 5/16) attended 16-20 lectures. Majority of fellows (88%, n = 14/16) reported the lecture series increased knowledge of liver disease, increased confidence in managing children with liver disease, and aided with board preparation. Additionally, over half of the fellows (81%, n = 13/16) reported the series served as a platform for networking and mentoring from peers and experts in the field. All fellows recommended the lecture series for future fellows. CONCLUSION: The SPLIT educational lectureship for advanced pediatric transplant hepatology trainees provided a national education curriculum that not only led to increased knowledge and confidence in the diagnosis and management of common conditions encountered in pediatric transplant hepatology but also provided a unique networking and mentorship environment.

Acute-on-chronic liver failure before liver transplantation does not impact post-transplant survival in children with biliary atresia.

Acute-on-chronic liver failure (ACLF) occurs in children with biliary atresia (BA) awaiting liver transplantation (LT). However, data on transplant outcomes in ACLF are limited. Our aim was to characterize ACLF and determine its effect on transplant outcome and resource utilization. Using a linkage of the Scientific Registry of Transplant Recipients and Pediatric Health Information System, we identified children with BA between 3 months and 18 years at the time of listing who received a transplant from 2003 to 2018 and were hospitalized while waiting. ACLF was defined by the presence of at least 1 extra-hepatic organ failure during a pre-LT hospitalization. In all, 1044 patients (58% female, median age at listing 7.0 months IQR 5.0-14.0) were included. Thirty-four percent (351/1044) of the patients had at least 1 ACLF hospitalization. Patients with ACLF had longer waitlist times (114 [54-231] vs. 81 [35-181] days, p < 0.001), and were more likely to be listed as Status 1 (8% vs. 4%, p = 0.02). Pre-LT resource utilization was significantly higher in ACLF patients. There were no differences in mortality at 30 days (ACLF 3% vs. No ACLF 2%, p = 0.17), 90 days (ACLF 3% vs. No ACLF 2%, p = 0.24), 1 year (ACLF 3% vs. No ACLF 2%, p =0.23), 3 years (ACLF 4% vs. No ACLF 3%, p = 0.58), or 5 years (ACLF 5% vs. No ACLF 4%, p = 0.38) after LT. ACLF status was not associated with increased post-transplant mortality (adjusted HR 1.51, 95% CI 0.76-3.0, p =0.25). ACLF is an important morbidity in children with BA awaiting LT as it is associated with higher resource utilization and longer waitlist times. Further studies are needed to help understand the spectrum of ACLF and better prioritize critically ill children awaiting LT, as our study shows successful post-LT outcomes in children with BA and ACLF.

Acute liver failure and unique challenges of pediatric liver transplantation amidst a worldwide cluster of adenovirus-associated hepatitis.

Investigation into a recent cluster of acute hepatitis in children from the southeastern United States identified human adenovirus (HAdV) DNAemia in all 9 cases. Molecular genotyping in 5 of 9 (56%) children identified HAdV type 41 in all cases (100%). Importantly, 2 children from this cluster progressed rapidly to pediatric acute liver failure (PALF) and required liver transplantation. HAdV type 41, a known cause of self-limited gastroenteritis, has not previously been associated with severe cholestatic hepatitis and liver failure in healthy children. Adenovirus polymerase chain reaction assay and sequencing of amplicons performed on DNA extracted from formalin-fixed, paraffin-embedded liver tissue also identified adenovirus species F (HAdV type 40 or 41) in these 2 children with PALF. Transplant considerations and successful liver transplantation in such situations remain scarce. In this report, we describe the clinical course, laboratory results, liver pathology, and treatment of 2 children with PALF associated with HAdV type 41, one of whom developed secondary hemophagocytic lymphohistiocytosis. Their successful posttransplant outcomes demonstrate the importance of early multidisciplinary medical management and the feasibility of liver transplantation in some children with PALF and HAdV DNAemia.

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 Case Series of Children with Acute Hepatitis and Human Adenovirus Infection.

BACKGROUND: Human adenoviruses typically cause self-limited respiratory, gastrointestinal, and conjunctival infections in healthy children. In late 2021 and early 2022, several previously healthy children were identified with acute hepatitis and human adenovirus viremia. METHODS: We used International Classification of Diseases, 10th Revision, codes to identify all children (<18 years of age) with hepatitis who were admitted to Children's of Alabama hospital between October 1, 2021, and February 28, 2022; those with acute hepatitis who also tested positive for human adenovirus by whole-blood quantitative polymerase chain reaction (PCR) were included in our case series. Demographic, clinical, laboratory, and treatment data were obtained from medical records. Residual blood specimens were sent for diagnostic confirmation and human adenovirus typing. RESULTS: A total of 15 children were identified with acute hepatitis - 6 (40%) who had hepatitis with an identified cause and 9 (60%) who had hepatitis without a known cause. Eight (89%) of the patients with hepatitis of unknown cause tested positive for human adenovirus. These 8 patients plus 1 additional patient referred to this facility for follow-up were included in this case series (median age, 2 years 11 months; age range, 1 year 1 month to 6 years 5 months). Liver biopsies indicated mild-to-moderate active hepatitis in 6 children, some with and some without cholestasis, but did not show evidence of human adenovirus on immunohistochemical examination or electron microscopy. PCR testing of liver tissue for human adenovirus was positive in 3 children (50%). Sequencing of specimens from 5 children showed three distinct human adenovirus type 41 hexon variants. Two children underwent liver transplantation; all the others recovered with supportive care. CONCLUSIONS: Human adenovirus viremia was present in the majority of children with acute hepatitis of unknown cause admitted to Children's of Alabama from October 1, 2021, to February 28, 2022, but whether human adenovirus was causative remains unclear. Sequencing results suggest that if human adenovirus was causative, this was not an outbreak driven by a single strain. (Funded in part by the Centers for Disease Control and Prevention.).

Our evolution in the treatment of hepatic artery and portal vein thrombosis in pediatric liver transplantation: Success with catheter-directed therapies.

BACKGROUND: In pediatric liver transplant recipients, hepatic artery thrombosis and portal vein thrombosis are major causes of acute graft failure and mortality within 30 days of transplantation. There is, however, a strong possibility of graft salvage if flow can be re-established to reduce ischemic injury. The current standard treatment is surgical revascularization, and if unsuccessful, retransplantation. Due to our success in treating these complications with catheter-directed therapies, we sought to summarize and publish the outcomes of all patients who experienced hepatic artery thrombosis or portal vein thrombosis within 30 days of liver transplantation. METHODS: We conducted a retrospective cohort analysis of 27 pediatric liver transplant recipients who experienced hepatic artery thrombosis (n = 13), portal vein thrombosis (n = 9), or both (n = 5) between September 2012 and March 2021. We collected and tabulated data on the patients and therapies performed to treat them, including success rates, primary and secondary patency, and clinical outcomes. RESULTS: Among these patients, 6 were managed with anticoagulation and relisting for transplant and 21 had a primary revascularization attempt. Surgical recanalization was attempted in 7 patients of which 3 had successful recanalization (43%) and catheter-directed recanalization was attempted in 14 patients with 100% success in re-establishing blood flow to the graft. Additionally, patency was increased, and mortality was decreased in patients treated with catheter-directed recanalization compared to surgical revascularization or anticoagulation alone. CONCLUSION: This data illustrates the need to further investigate catheter-directed thrombolysis as a potential first-line treatment for postoperative HAT and PVT in pediatric liver transplant recipients.

A Case of Syphilitic Hepatitis in an Adolescent.

The incidence of syphilis is rising among adolescents necessitating improved provider awareness and screening practices. We present a case of an adolescent with acute hepatitis ultimately diagnosed with secondary syphilitic hepatitis. Clinical presentation, laboratory abnormalities, and histologic features of syphilitic hepatitis are nonspecific, with diagnosis relying on clinical suspicion and targeted testing. This case highlights the importance of screening for syphilis in sexually active adolescents with acute hepatitis. The rising incidence of syphilis among adolescents, and the variety of clinical manifestations including those commonly seen by pediatric gastroenterologists, makes elevated clinical suspicion essential to prompt diagnosis and treatment. With improved provider awareness across general pediatric and subspecialty providers, the transmission of syphilis among adolescent patients can be reduced.

Bivalirudin for the prevention of hepatic artery thrombosis in pediatric liver transplantation.

BACKGROUND: Early hepatic artery thrombosis (HAT) after liver transplantation is a serious complication that frequently results in graft loss and the need for retransplantation. Although studies have reported on various operative and endovascular treatment approaches, pharmacologic strategies for the prevention or management of HAT are not well defined. Patients with blood clotting disorders, those with a contraindication to heparin, and those who have previously developed HAT represent unique challenges in management. METHODS: We present the case of a 9-month-old male with a hypercoagulable state who developed early HAT after two liver transplants, despite the use of postoperative therapeutic heparin infusion. RESULTS AND CONCLUSION: The patient successfully underwent a third liver transplant using intraoperative and postoperative bivalirudin infusion, a direct thrombin inhibitor. Rotational thromboelastometry (ROTEM) was used to guide anticoagulation and blood product administration in the perioperative period. At 1.5 years post-transplant, the patient has good graft function with patent hepatic vasculature. This case demonstrates the innovative use of bivalirudin anticoagulant therapy and viscoelastic methodologies to improve outcomes in hypercoagulable liver transplant recipients.

Transient Elastography in Pediatric Liver Disease.

ABSTRACT: Transient elastography is an imaging technique utilizing shear wave technology to measure liver stiffness. Recent studies have shown success in utilizing this technique in children. Transient elastography is useful in estimating degree of fibrosis in various pediatric liver diseases, including biliary atresia, alpha-1-antitrypsin deficiency, Alagille syndrome, cystic fibrosis-related liver disease, and non-alcoholic steatohepatitis among others. Confounding factors, however, may affect elastography measurements, such as obesity, severe inflammation, nonfasting state, and hepatic congestion, and should be considered whenever interpreting these measurements. Future studies will correlate liver stiffness on transient elastography and severity of disease.

Applying an Age-specific Definition to Better Characterize Etiologies and Outcomes in Neonatal Acute Liver Failure.

OBJECTIVE: Neonatal acute liver failure (ALF) is a rare disease with high mortality for which no standard age-specific definition exists. To advance the understanding of neonatal ALF, we characterize the etiology, presenting features, treatment, and outcomes in infants within 1 month of life. METHODS: We performed a single-center 11-year retrospective chart review of neonates ≤30 days of life with ALF as defined by an INR of ≥2.0. Comparisons were made by etiology and survival with native liver (SNL). Estimated survival was performed using the Kaplan-Meier method. RESULTS: Forty-three patients met inclusion criteria for neonatal ALF. Etiologies included viral infection (23%), gestational alloimmune liver disease with neonatal hemochromatosis (GALD-NH) (21%), cardiac-associated ischemia (16%), other ischemia (14%), genetic etiologies (9%), Trisomy 21-associated myelodysplasia (TAM) (7%), hemophagocytic lymphohistiocytosis (HLH) (2%), and not identified (7%). Infants with viral etiologies had the highest alanine aminotransferase (ALT) at presentation (1179 IU/L, interquartile range [IQR] 683-1585 IU/L) in contrast to low levels in GALD-NH (23 IU/L, IQR 18-64 IU/L). Across all etiologies, only 33% were alive at 1 year. Overall median survival was 74 days; 17 days for viral infection and 74 days for GALD-NH. Among laboratory values at presentation, alpha-fetoprotein (AFP) was significantly higher in patients that survived with their native liver (P = 0.04). CONCLUSIONS: Overall, outcome for neonatal ALF is poor. Although initial laboratory values can differentiate viral infection or GALD-NH, further studies are needed to identify laboratory parameters that predict SNL by etiology to ultimately improve patient outcomes.

Dexmedetomidine leading to profound bradycardia in a pediatric liver transplant recipient.

Dexmedetomidine, an α2 -agonist, is used in the PICU for its sedative properties as it minimally affects respiratory status. However, hemodynamic instability is one of its known side effects. There is limited published experience with its use in pediatric liver transplant. We present a case of a 9-month-old infant who received a deceased donor liver transplantation for biliary atresia and received an IV dexmedetomidine infusion for sedation starting at 20 hours post-operatively. The patient received an IV bolus of 0.08 mcg/kg followed by an increase to 1 mcg/kg/hour. She was also receiving a fentanyl infusion for sedation at the time of dexmedetomidine initiation. Approximately 3 hours after initiation, she developed bradycardia as low as 30 beats-per-minute with an associated sinus pause of 7 seconds. She was given chest compressions by the bedside nurse briefly before arousing and becoming agitated. Evaluation of other etiologies for the patient's bradycardia was unrevealing. Thus, bradycardia was attributed to dexmedetomidine therapy which was discontinued without recurrence. Hemodynamic instability, specifically bradycardia, is known to occur with dexmedetomidine administration. As this medication is primarily metabolized by the liver, its use immediately after transplantation, when liver function is still recovering, may be associated with an increased risk of side effects. Understanding risk factors for bradycardia and hemodynamic instability early after liver transplantation, particularly with dexmedetomidine, is critical to allow clinicians to identify the patients for higher risk for dexmedetomidine side effects.

Admission Characteristics Identify Risk of Pediatric Acute-on-Chronic Liver Failure.

OBJECTIVES: Acute-on-chronic liver failure (ACLF) is well-studied in adults and characterized by decompensated cirrhosis, multi-organ failure, and early mortality. Studies of ACLF in children are limited. We sought to characterize the prevalence and clinical factors associated with pediatric ACLF (PACLF). METHODS: A retrospective review of children 3 months to 18 years listed for liver transplantation and hospitalized for decompensated cirrhosis between January 2007 and December 2017 at a single pediatric hospital. Primary outcome was the development of PACLF, characterized as failure of at least 1 extrahepatic organ (mechanical ventilation, renal replacement therapy, vasoactive medications, grade III/IV hepatic encephalopathy). Characteristics were recorded for each hospitalization. RESULTS: Sixty-six patients had 186 hospitalizations with mean age at admission 4.0 ±â€Š5.6 years and diagnosis of biliary atresia (BA) in 65%. PACLF developed in 20 patients during 23 hospitalizations (12%) and respiratory failure was most common (17/23, 74%). Duration of intensive care unit stay, 13.1 ±â€Š1.2 days versus 0.6 ±â€Š0.6 days (P < 0.001) and length of stay, 24.3 ±â€Š5.0 days versus 7.9 ±â€Š1.9 days (P = 0.003) were longer in PACLF compared with non-PACLF. Mortality during PACLF hospitalizations was 22%. Clinical factors associated with PACLF were reported from a generalized linear mixed model and included increased admission creatinine (P < 0.0001), increased aspartate aminotransferase (AST) (P = 0.014), increased international normalized ration (INR) (P = 0.0015), and a positive blood culture (P = 0.007). CONCLUSION: In this pediatric series, PACLF developed in 12% of hospitalizations and mortality was high. Admission creatinine, AST, INR, and presence of a positive blood culture were associated with PACLF development.

Therapeutic Endoscopy for the Control of Nonvariceal Upper Gastrointestinal Bleeding in Children: A Case Series.

OBJECTIVES: Gastrointestinal bleeding is one of the most common indications for urgent endoscopy in the pediatric setting. The majority of these procedures are performed for control of variceal bleeding, with few performed for nonvariceal upper gastrointestinal (NVUGI) bleeding. The data on therapeutic endoscopy for NVUGI are sparse. The aims of our study were to review our experience with NVUGI bleeding, describe technical aspects and outcomes of therapeutic endoscopy, and determine gastroenterology fellows' training opportunities according to the national training guidelines. METHODS: We performed a retrospective review of endoscopy database (Endoworks, Olympus Inc, Center Valley, PA) from January 2009 to December 2014. The search used the following keywords: bleeding, hematemesis, melena, injection, epinephrine, cautery, clip, and argon plasma coagulation. The collected data included demographics, description of bleeding lesion and medical/endoscopic therapy, rate of rebleeding, relevant laboratories, physical examination, and need for transfusion and surgery. The study was approved by the institutional review board. RESULTS: During the study period 12,737 upper endoscopies (esophagogastroduodenoscopies) were performed. A total of 15 patients underwent 17 esophagogastroduodenoscopies that required therapeutic intervention to control bleeding (1:750 procedures). The mean ±â€Šstandard deviation (median) age of patients who required endoscopic intervention was 11.6 ±â€Š6.0 years (14.0 years). Seven out of 17 patients received dual therapy to control the bleeding lesions. All but 3 patients received medical therapy with intravenous proton pump inhibitor, and 3 received octreotide infusions. Six of the patients experienced rebleeding (40%), with 4 out of 6 initially only receiving single modality therapy. Two of these patients eventually required surgical intervention to control bleeding and both patients presented with bleeding duodenal ulcers. There were no cases of aspiration, perforation, or deaths. There were a total of 24 fellows trained in our program during the study period. Less than 1 therapeutic endoscopy per fellow for NVUGI bleeding was performed. CONCLUSIONS: NVUGI bleeding requiring therapeutic endoscopic intervention is rare in pediatrics. A high rate (40%) of rebleeding was noted with a large proportion (66%) of patients receiving single modality therapy. Two patients required surgical intervention to control bleeding and both presented with bleeding duodenal ulcers. An insufficient number of therapeutic procedures is available for adequate fellow training requiring supplemental simulator and hands-on animal model, or adult endoscopy unit training.

Resolution of Hepatic Artery Thrombosis in 2 Pediatric Liver Transplant Patients.

Hepatic artery thrombosis (HAT) is a serious complication after liver transplantation. This is the first report of spontaneous resolution of HAT in pediatric liver transplant patients on low molecular weight heparin therapy. A total of 2 patients, a 26-month-old boy who presented with acute liver failure and required emergent liver transplantation and a 15-year-old boy with ulcerative colitis and autoimmune hepatitis-primary sclerosing cholangitis overlap underwent liver transplantation for progressive cirrhosis; both developed HAT during the postoperative period. They were both treated with low molecular weight heparin. Follow-up imaging for both patients showed resolution of HAT without evidence of collateral flow.