Cholangioscopy in Children and Adolescents: Utilization, Outcomes, and Safety.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is increasingly utilized for management of biliary disorders in children and adolescents. Practice patterns surrounding cholangioscopy in pediatric patients, however, are largely uncharacterized. METHODS: We retrospectively analyzed all ERCPs in which cholangioscopy was performed on patients 18 and under at our tertiary care children's hospital from 2015 to 2020 using our institution's paper and electronic medical record system. Patient demographics, procedure indications, interventions, and associated adverse events were analyzed. RESULTS: Over the study period, 307 ERCPs were performed on 282 patients at our children's hospital. Cholangioscopy was performed in 36 procedures (11.7%) using the SpyGlass cholangioscope (Boston Scientific). Antibiotics to cover biliary organisms were administered to all patients precholangioscopy. Mean patient age was 13.6 years (range 7-18 years). The 2 most common indications for cholangioscopy included electrohydraulic lithotripsy for biliary stone disease and evaluation of biliary stricture (with incidental finding of biliary web in 2 patients and retained suture material in 2 patients). Adverse events were less prevalent in patients who underwent cholangioscopy relative to those who underwent ERCP. 0/36 (0%) developed post-ERCP pancreatitis, one patient had self-limited melena (possible self-limited postsphincterotomy bleeding). Patient care was enhanced by cholangioscopy in 30/36 (83.3%) of these patients. CONCLUSIONS: These data attest to the safety and clinical utility of cholangioscopy in children and adolescents. Cholangioscopy was performed in just over 11% of pediatric patients who underwent ERCP at our academic medical center-rates similar to those reported in adult patients. The radiation-sparing nature of cholangioscopy, coupled with these data supporting its safety, make it particularly appealing for use in children. Further multi-institution evaluation of the utility, safety, and range of indications for cholangioscopy in other practice settings would be of great interest and help guide endoscopic care.

Fluoroscopy Time During Endoscopic Retrograde Cholangiopancreatography Performed for Children and Adolescents is Significantly Higher With Low-volume Endoscopists.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is a fluoroscopy and endoscopy-based procedure important for diagnosis and management of pediatric pancreaticobiliary disorders. Patient, procedure, endoscopist, and facility characteristics have been shown to influence ERCP complexity and procedure outcomes as well as fluoroscopy utilization in adults; however, the extent to which this is true in pediatric patients remains under-studied and there are minimal data regarding fluoroscopy utilization in pediatric ERCP. METHODS: We retrospectively analyzed ERCPs performed on patients <18 years of age at our tertiary care children's hospital from 2002 to 2017 using our institution's paper and electronic medical record system along with a prospectively maintained radiation exposure database. Procedure complexity was graded using the Stanford Fluoroscopy Complexity Score and the American Society of Gastrointestinal Endoscopy Complexity scale. High-volume endoscopists (HVE) were defined as having a cumulative annual ERCP volume >100 and low-volume endoscopists (LVE) as <100 (pediatric + adult) ERCPs/year. RESULTS: Three hundred eighty-five ERCPs performed on 321 patients were included in this analysis. The mean patient age was 13.4 years (+/- 4.2 years), 77% were index ERCPs (native ampullas), and 81% were performed with therapeutic intent (87% for biliary indication and 13% for pancreatic indication). Fluoroscopy times (FTs) varied between procedures and providers. Median FT was 4.85 (+/- 2.68) minutes. Endoscopist annual ERCP volume was the strongest predictor of FT (P < 0.001). In addition to endoscopist volume, procedure-specific predictors of increased FT included pancreatic indication for the procedure, biliary or pancreatic duct stricture, patient age <4 years or >16 years at the time of ERCP (P < 0.01 for each), and native ampulla. ERCP complexity rating based on the Stanford Fluoroscopy Complexity Score correlated with FT. CONCLUSIONS: Radiation exposure is higher than desirable for pediatric ERCP and varies with endoscopist as well as patient and procedure-specific factors. HVE perform ERCP with lower FT relative to LVE even though HVE procedure complexity was higher. The Stanford Fluoroscopy Score predicted FT for pediatric ERCP, but the ASGE ERCP complexity scale did not. Adaptation and refinement of pediatric-specific ERCP complexity scales including factors, such as patient size and age and indications/interventions more consistent with those encountered in pediatrics could be beneficial.

Nationwide Evolution of Pediatric Endoscopic Retrograde Cholangiopancreatography Indications, Utilization, and Readmissions over Time.

OBJECTIVES: To analyze outcome and utilization trends over time of pediatric endoscopic retrograde cholangiopancreatography (ERCP) in an all-capture US population-level study. STUDY DESIGN: Using the National Inpatient Sample (2005-2014) and National Readmission Database (2010-2014), we identified pediatric (age <20 years) hospitalizations during which ERCP was performed and assessed ERCP-associated readmissions. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify hospitalization diagnoses, comorbidities, and patient/hospital characteristics. Multivariate logistic regression analyses were performed to determine significant predictors (P < .05) of 30-day readmission. RESULTS: A total of 11 060 hospitalized pediatric patients underwent ERCP between 2005 and 2014. Most were female (n = 8859; 81%), aged 14-20 years (n = 9342; 84%), and white (n = 4230; 45%). Most (85%) of ERCPs were therapeutic, and leading indications were biliary (n = 5350; 48%) and pancreatitis (n = 3218; 29%). Thirteen pecent of patients were readmitted post-ERCP. Odds for 30-day readmission were highest for patients with a history of liver transplantation, age 0-4 years, male sex, and obesity (P < .001 for each). Patients in both urban teaching and urban hospitals had much lower odds than those in rural hospitals for prolonged length of stay associated with ERCP. CONCLUSIONS: These data represent a comprehensive study of nationwide trends in age-specific volumes and outcomes following ERCP in the pediatric population and provide important insights into trends in pediatric pancreaticobiliary disease management, as well as practice setting, patient characteristics, and patient comorbidities associated with pediatric post-ERCP outcomes, including readmission and length of stay.

Open-label prospective therapeutic clinical trials: oral vancomycin in children and adults with primary sclerosing cholangitis.

BACKGROUND: Oral vancomycin (OV) in primary sclerosing cholangitis (PSC) has been evaluated as a potential therapeutic agent. We report the long-term biochemical course and outcomes of patients with PSC treated with OV. METHODS: Patients were enrolled in 2 open-label clinical trials (ClinicalTrials.gov Identifier: NCT01802073 and NCT01322386) and offered OV at 50 mg/kg/day in 3 divided doses if weight <30kg, and 500 mg 3 times/day if weight ≥30kg. Patients with biliary strictures requiring stenting or awaiting liver transplant were excluded. Liver biochemistry, MRCP and histology were documented at baseline and while on OV. The primary outcome was a decrease in elevated gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), and/or alanine aminotransferase (ALT) from baseline. RESULTS: 30 subjects were enrolled, and 29 additional subjects who learned of the clinical trial requested OV (total n = 59; median age was 13.5 years [range, 1.5-44 years]; 64.4% were male; and 94.9% had inflammatory bowel disease [IBD]). The median treatment duration was 2.7 years (range, 0.2-14 years). Ninety-six percent (57/59), 81.3% (48/59), and 94.9% (56/59) experienced reduction of GGT, ALP, and ALT, respectively. Furthermore, 39% (23/59), 22% (13/59), and 55.9% (33/59) experienced normalization of GGT, ALP, and ALT, respectively, within the first 6 months of OV treatment. One patient underwent liver transplantation 8 years after beginning OV treatment, and one developed biliary strictures requiring endoscopic intervention. OV was well-tolerated by patients, and no patient developed treatment-related adverse events. CONCLUSION: In PSC, OV was well-tolerated and was associated with improvement in liver chemistry. A randomized placebo-controlled clinical trial is warranted.

Successful liver transplantation in mitochondrial neurogastrointestinal encephalomyopathy (MNGIE).

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a fatal disorder characterized by progressive gastrointestinal dysmotility, peripheral neuropathy, leukoencephalopathy, skeletal myopathy, ophthalmoparesis, and ptosis. MNGIE stems from deficient thymidine phosphorylase activity (TP) leading to toxic elevations of plasma thymidine. Hematopoietic stem cell transplant (HSCT) restores TP activity and halts disease progression but has high transplant-related morbidity and mortality. Liver transplant (LT) was reported to restore TP activity in two adult MNGIE patients. We report successful LT in four additional MNGIE patients, including a pediatric patient. Our patients were diagnosed between ages 14 months and 36 years with elevated thymidine levels and biallelic pathogenic variants in TYMP. Two patients presented with progressive gastrointestinal dysmotility, and three demonstrated progressive peripheral neuropathy with two suffering limitations in ambulation. Two patients, including the child, had liver dysfunction and cirrhosis. Following LT, thymidine levels nearly normalized in all four patients and remained low for the duration of follow-up. Disease symptoms stabilized in all patients, with some manifesting improvements, including intestinal function. No patient died, and LT appeared to have a more favorable safety profile than HSCT, especially when liver disease is present. Follow-up studies will need to document the long-term impact of this new approach on disease outcome. Take Home Message: Liver transplantation is effective in stabilizing symptoms and nearly normalizing thymidine levels in patients with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) and may have an improved safety profile over hematopoietic stem cell transplant.

Long-term safety and efficacy of glycerol phenylbutyrate for the management of urea cycle disorder patients.

INTRODUCTION: Glycerol phenylbutyrate (GPB) is currently approved for use in the US and Europe for patients of all ages with urea cycle disorders (UCD) who cannot be managed with protein restriction and/or amino acid supplementation alone. Currently available data on GPB is limited to 12 months exposure. Here, we present long-term experience with GPB. METHODS: This was an open-label, long-term safety study of GPB conducted in the US (17 sites) and Canada (1 site) monitoring the use of GPB in UCD patients who had previously completed 12 months of treatment in the previous safety extension studies. Ninety patients completed the previous studies with 88 of these continuing into the long-term evaluation. The duration of therapy was open ended until GPB was commercially available. The primary endpoint was the rate of adverse events (AEs). Secondary endpoints were venous ammonia levels, number and causes of hyperammonemic crises (HACs) and neuropsychological testing. RESULTS: A total of 45 pediatric patients between the ages of 1 to 17 years (median 7 years) and 43 adult patients between the ages of 19 and 61 years (median 30 years) were enrolled. The treatment emergent adverse events (TEAE) reported in ≥10% of adult or pediatric patients were consistent with the TEAEs reported in the previous safety extension studies with no increase in the overall incidence of TEAEs and no new TEAEs that indicated a new safety signal. Mean ammonia levels remained stable and below the adult upper limit of normal (<35 µmol/L) through 24 months of treatment in both the pediatric and adult population. Over time, glutamine levels decreased in the overall population. The mean annualized rate of HACs (0.29) established in the previously reported 12-month follow-up study was maintained with continued GPB exposure. CONCLUSION: Following the completion of 12-month follow-up studies with GPB treatment, UCD patients were followed for an additional median of 1.85 (range 0 to 5.86) years in the present study with continued maintenance of ammonia control, similar rates of adverse events, and no new adverse events identified.

Pediatric Endoscopy Practice Patterns in the United States, Canada, and Mexico.

BACKGROUND AND AIMS: Endoscopic procedures are important for diagnosis and management of many gastrointestinal, liver, and biliary conditions in children. Therapeutic endoscopy procedures, including endoscopic retrograde cholangiopancreatography (ERCP), are performed less frequently in children relative to adults. A formal study to evaluate institutional volumes and practice patterns for advanced therapeutic pediatric endoscopy procedures has, however, not been previously undertaken. METHODS: A self-administered 16-question (5-minute) online survey assessing practice patterns for performance of pediatric endoscopy procedures was distributed to all registered North American Society for Pediatric Gastroenterology, Hepatology and Nutrition programs. Results were analyzed using descriptive statistics and thematic analysis of free-text comments. RESULTS: Respondents from 82.9% of North American Society for Pediatric Gastroenterology, Hepatology and Nutrition centers completed this survey. Responses revealed that esophagogastroduodenoscopy/colonoscopy are performed at the vast majority of centers (>90%), with most performing >50/year. Therapeutic endoscopy procedures are performed less frequently in the pediatric population, with 18.97% reporting that ERCP is not performed at their institution. Where ERCP is performed, 91.38% reported <25/year. Endoscopic ultrasound is not performed at more than half (53.33%) of institutions. Approximately 71.67% of respondents do not believe their institution's current arrangement for performing pediatric therapeutic endoscopy procedures is adequate. CONCLUSIONS: Although the range of endoscopic procedures performed in children parallels that performed in adults, there are notable differences in pediatric and adult gastroenterologists' endoscopy training and procedure volumes. Our results and respondent comments suggest that pediatric patients would benefit from a partnership between pediatric and adult gastroenterologists, with adult gastroenterologists performing more complex therapeutic endoscopic procedures.

Prenatal treatment of ornithine transcarbamylase deficiency.

PURPOSE OF STUDY: Patients with neonatal urea cycle defects (UCDs) typically experience severe hyperammonemia during the first days of life, which results in serious neurological injury or death. Long-term prognosis despite optimal pharmacological and dietary therapy is still poor. The combination of intravenous sodium phenylacetate and sodium benzoate (Ammonul®) can eliminate nitrogen waste independent of the urea cycle. We report attempts to improve outcomes for males with severe ornithine transcarbamylase deficiency (OTCD), a severe X-linked condition, via prenatal intravenous administration of Ammonul and arginine to heterozygous carrier females of OTCD during labor. METHODS USED: Two heterozygote OTCD mothers carrying male fetuses with a prenatal diagnosis of OTCD received intravenous Ammonul, arginine and dextrose-containing fluids shortly before birth. Maintenance Ammonul and arginine infusions and high-caloric enteral nutrition were started immediately after birth. Ammonul metabolites were measured in umbilical cord blood and the blood of the newborn immediately after delivery. Serial ammonia and biochemical analyses were performed following delivery. SUMMARY OF RESULTS: Therapeutic concentrations of Ammonul metabolites were detected in umbilical cord and neonatal blood samples. Plasma ammonia and glutamine levels in the postnatal period were within the normal range. Peak ammonia levels in the first 24-48h were 53mcmol/l and 62mcmol/l respectively. The boys did not experience neurological sequelae secondary to hyperammonemia and received liver transplantation at ages 3months and 5months. The patients show normal development at ages 7 and 3years. CONCLUSION: Prenatal treatment of mothers who harbor severe OTCD mutations and carry affected male fetuses with intravenous Ammonul and arginine, followed by immediate institution of maintenance infusions after delivery, results in therapeutic levels of benzoate and phenylacetate in the newborn at delivery and, in conjunction with high-caloric enteral nutrition, prevents acute hyperammonemia and neurological decompensation. Following initial medical management, early liver transplantation may improve developmental outcome.

Initial experience with peroral endoscopic myotomy for treatment of achalasia in children.

BACKGROUND: Achalasia is a primary esophageal motility disorder characterized by aperistalsis of the esophagus and failed relaxation of the lower esophageal sphincter that presents rarely in childhood. The peroral endoscopic myotomy (POEM) procedure is an emerging treatment for achalasia in adults that has recently been introduced into pediatric surgical practice. METHODS: This is a prospective case series of all children referred to Stanford University Lucile Packard Children's Hospital with manometry-confirmed achalasia who underwent a POEM procedure from 2014 to 2016. RESULTS: We enrolled 10 subjects ranging in age from 7 to 17years (M=13.4). The mean pre- and 1-month post-procedure Eckardt scores were 7 (SD=2.5) and 2.4 (SD=2) (p<0.001), respectively. The median procedure time for the entire cohort was 142min (range 60-259min) with ongoing improvement with increased experience (R2=0.6, p=0.008). There were no major adverse events. CONCLUSION: The POEM procedure can be successfully completed in children for the treatment of achalasia with demonstrated short-term post-operative improvement in symptoms. The adoption of advanced endoscopic techniques by pediatric surgeons may enable development of unique intraluminal approaches to congenital anomalies and other childhood diseases. LEVEL OF EVIDENCE: Treatment Study - Level IV.

Mass cytometry reveals a distinct immunoprofile of operational tolerance in pediatric liver transplantation.

Long-term IS in transplant patients has significant morbidity, poorer quality of life, and substantial economic costs. TOL, defined as graft acceptance without functional impairment in the absence of IS, has been achieved in some pediatric LT recipients. Using mass cytometry, peripheral blood immunotyping was performed to characterize differences between tolerant patients and patients who are stable on single-agent IS. Single-cell mass cytometry was performed using blood samples from a single-center pediatric LT population of operationally tolerant patients to comprehensively characterize the immune cell populations in the tolerant state compared with patients on chronic low-dose IS. Specific T-cell populations of interest were confirmed by flow cytometry. This high-dimensional phenotypic analysis revealed distinct immunoprofiles between transplant populations as well as a CD4+ TOT (CD4+ CD5+ CD25+ CD38-/lo CD45RA) that correlates with tolerance in pediatric LT recipients. In TOL patients, the TOT was significantly increased as compared to patients stable on low levels of IS. This TOT cell was confirmed by flow cytometry and is distinct from classic Treg cells. These results demonstrate the power of mass cytometry to discover significant immune cell signatures that have diagnostic potential.

Protein and calorie intakes in adult and pediatric subjects with urea cycle disorders participating in clinical trials of glycerol phenylbutyrate.

BACKGROUND: Little prospectively collected data are available comparing the dietary intake of urea cycle disorder (UCD) patients to UCD treatment guidelines or to healthy individuals. OBJECTIVE: To examine the protein and calorie intakes of UCD subjects who participated in clinical trials of glycerol phenylbutyrate (GPB) and compare these data to published UCD dietary guidelines and nutritional surveys. DESIGN: Dietary data were recorded for 45 adult and 49 pediatric UCD subjects in metabolic control during participation in clinical trials of GPB. Protein and calorie intakes were compared to UCD treatment guidelines, average nutrient intakes of a healthy US population based on the National Health and Nutrition Examination Survey (NHANES) and Recommended Daily Allowances (RDA). RESULTS: In adults, mean protein intake was higher than UCD recommendations but lower than RDA and NHANES values, while calorie intake was lower than UCD recommendations, RDA and NHANES. In pediatric subjects, prescribed protein intake was higher than UCD guidelines, similar to RDA, and lower than NHANES data for all age groups, while calorie intake was at the lower end of the recommended UCD range and close to RDA and NHANES data. In pediatric subjects height, weight, and body mass index (BMI) Z-scores were within normal range (- 2 to 2). CONCLUSIONS: Pediatric patients treated with phenylbutyrate derivatives exhibited normal height and weight. Protein and calorie intakes in adult and pediatric UCD subjects differed from UCD dietary guidelines, suggesting that these guidelines may need to be reconsidered.

Mutations in the nuclear bile acid receptor FXR cause progressive familial intrahepatic cholestasis.

Neonatal cholestasis is a potentially life-threatening condition requiring prompt diagnosis. Mutations in several different genes can cause progressive familial intrahepatic cholestasis, but known genes cannot account for all familial cases. Here we report four individuals from two unrelated families with neonatal cholestasis and mutations in NR1H4, which encodes the farnesoid X receptor (FXR), a bile acid-activated nuclear hormone receptor that regulates bile acid metabolism. Clinical features of severe, persistent NR1H4-related cholestasis include neonatal onset with rapid progression to end-stage liver disease, vitamin K-independent coagulopathy, low-to-normal serum gamma-glutamyl transferase activity, elevated serum alpha-fetoprotein and undetectable liver bile salt export pump (ABCB11) expression. Our findings demonstrate a pivotal function for FXR in bile acid homeostasis and liver protection.

Self-reported treatment-associated symptoms among patients with urea cycle disorders participating in glycerol phenylbutyrate clinical trials.

BACKGROUND: Health care outcomes have been increasingly assessed through health-related quality of life (HRQoL) measures. While the introduction of nitrogen-scavenging medications has improved survival in patients with urea cycle disorders (UCDs), they are often associated with side effects that may affect patient compliance and outcomes. METHODS: Symptoms commonly associated with nitrogen-scavenging medications were evaluated in 100 adult and pediatric participants using a non-validated UCD-specific questionnaire. Patients or their caregivers responded to a pre-defined list of symptoms known to be associated with the use of these medications. Responses were collected at baseline (while patients were receiving sodium phenylbutyrate [NaPBA]) and during treatment with glycerol phenylbutyrate (GPB). RESULTS: After 3 months of GPB dosing, there were significant reductions in the proportion of patients with treatment-associated symptoms (69% vs. 46%; p<0.0001), the number of symptoms per patient (2.5 vs. 1.1; p<0.0001), and frequency of the more commonly reported individual symptoms such as body odor, abdominal pain, nausea, burning sensation in mouth, vomiting, and heartburn (p<0.05). The reduction in symptoms was observed in both pediatric and adult patients. The presence or absence of symptoms or change in severity did not correlate with plasma ammonia levels or NaPBA dose. CONCLUSIONS: The reduction in symptoms following 3 months of open-label GPB dosing was similar in pediatric and adult patients and may be related to chemical structure and intrinsic characteristics of the product rather than its effect on ammonia control.

Text Messaging Improves Participation in Laboratory Testing in Adolescent Liver Transplant Patients.

BACKGROUND: In solid organ transplant patients, non-participation in all aspects of the medical regimen is a prevalent problem associated with adverse consequences particularly in the adolescent and young adult (AYA) age group. This study is the first to evaluate the feasibility, utility and impact of a text messaging (TM) intervention to improve participation in laboratory testing in adolescent liver transplant patients. METHODS: AYA patients, aged 12 to 21 years, were recruited for a prospective pilot trial evaluating a TM intervention delivered over a 1-year period. The intervention involved automated TM reminders with feedback administered according to a prescribed laboratory testing frequency. Participation rate in laboratory testing after the intervention was compared to the year prior. Patient responses and feedback by text and survey were used to assess feasibility, acceptability and use of the intervention. RESULTS: Forty-two patients were recruited and 33 patients remained enrolled for the study duration. Recipients of the TM intervention demonstrated a significant improvement in participation rate in laboratory testing from 58% to 78% (P<.001). This rate was also significantly higher than in non-intervention controls (P=.003). There was a high acceptability, response rate and a significant correlation with reported versus actual completion of laboratory tests by TM. CONCLUSIONS: TM reminders significantly improved participation in laboratory testing in AYA liver transplant patients. The intervention demonstrated feasibility, acceptability, and use with a high proportion of patients who engaged in and perceived a benefit from using this technology.