Bernadette Vitola

Alterations in fatty acid kinetics in obese adolescents with increased intrahepatic triglyceride content.

Objective: It has been hypothesized that excessive fatty acid availability contributes to steatosis and the metabolic abnormalities associated with nonalcoholic fatty liver disease (NAFLD). The purpose of this study was to evaluate whether adipose tissue lipolytic activity and the rate of fatty acid release into plasma are increased in obese adolescents with NAFLD.

Weight Loss Reduces Liver Fat and Improves Hepatic and Skeletal Muscle Insulin Sensitivity in Obese Adolescents

Obesity in adolescents is associated with metabolic risk factors for type 2 diabetes, particularly insulin resistance and excessive accumulation of intrahepatic triglyceride (IHTG). The purpose of this study was to evaluate the effect of moderate weight loss on IHTG content and insulin sensitivity in obese adolescents who had normal oral glucose tolerance. Insulin sensitivity, assessed by using the hyperinsulinemic–euglycemic clamp technique in conjunction with stable isotopically labeled tracer infusion, and IHTG content, assessed by using magnetic resonance spectroscopy, were evaluated in eight obese adolescents (BMI ≥95th percentile for age and sex; age 15.3 ± 0.6 years) before and after moderate diet‐induced weight loss (8.2 ± 2.0% of initial body weight). Weight loss caused a 61.6 ± 8.5% decrease in IHTG content (P = 0.01), and improved both hepatic (56 ± 18% increase in hepatic insulin sensitivity index, P = 0.01) and skeletal muscle (97 ± 45% increase in insulin‐mediated glucose disposal, P = 0.01) insulin sensitivity. Moderate diet‐induced weight loss decreases IHTG content and improves insulin sensitivity in the liver and skeletal muscle in obese adolescents who have normal glucose tolerance. These results support the benefits of weight loss therapy in obese adolescents who do not have evidence of obesity‐related metabolic complications during a standard medical evaluation.

Alterations in Ventricular Structure and Function in Obese Adolescents with Nonalcoholic Fatty Liver Disease

OBJECTIVE To determine the association among nonalcoholic fatty liver disease (NAFLD), metabolic function, and cardiac function in obese adolescents. STUDY DESIGN Intrahepatic triglyceride (IHTG) content (magnetic resonance spectroscopy), insulin sensitivity and β-cell function (5-hour oral glucose tolerance test with mathematical modeling), and left ventricular function (speckle tracking echocardiography) were determined in 3 groups of age, sex, and Tanner matched adolescents: (1) lean (n=14, body mass index [BMI]=20±2 kg/m2); (2) obese with normal (2.5%) IHTG content (n=15, BMI=35±3 kg/m2); and (3) obese with increased (8.7%) IHTG content (n=15, BMI=37±6 kg/m2). RESULTS The disposition index (β-cell function) and insulin sensitivity index were ∼45% and ∼70% lower, respectively, and whole body insulin resistance, calculated by homeostasis model of assessment-insulin resistance (HOMA-IR), was ∼60% greater, in obese than in lean subjects, and ∼30% and ∼50% lower and ∼150% greater, respectively, in obese subjects with NAFLD than those without NAFLD (P<.05 for all). Left ventricular global longitudinal systolic strain and early diastolic strain rates were significantly decreased in obese than in lean subjects, and in obese subjects with NAFLD than those without NAFLD (P<.05 for all), and were independently associated with HOMA-IR (β=0.634). IHTG content was the only significant independent determinant of insulin sensitivity index (β=-0.770), disposition index (β=-0.651), and HOMA-IR (β=0.738). CONCLUSIONS These findings demonstrate that the presence of NAFLD in otherwise asymptomatic obese adolescents is an early marker of cardiac dysfunction.

The natural history of primary sclerosing cholangitis in 781 children: A multicenter, international collaboration

There are limited data on the natural history of primary sclerosing cholangitis (PSC) in children. We aimed to describe the disease characteristics and long‐term outcomes of pediatric PSC. We retrospectively collected all pediatric PSC cases from 36 participating institutions and conducted a survival analysis from the date of PSC diagnosis to dates of diagnosis of portal hypertensive or biliary complications, cholangiocarcinoma, liver transplantation, or death. We analyzed patients grouped by disease phenotype and laboratory studies at diagnosis to identify objective predictors of long‐term outcome. We identified 781 patients, median age 12 years, with 4,277 person‐years of follow‐up; 33% with autoimmune hepatitis, 76% with inflammatory bowel disease, and 13% with small duct PSC. Portal hypertensive and biliary complications developed in 38% and 25%, respectively, after 10 years of disease. Once these complications developed, median survival with native liver was 2.8 and 3.5 years, respectively. Cholangiocarcinoma occurred in 1%. Overall event‐free survival was 70% at 5 years and 53% at 10 years. Patient groups with the most elevated total bilirubin, gamma‐glutamyltransferase, and aspartate aminotransferase‐to‐platelet ratio index at diagnosis had the worst outcomes. In multivariate analysis PSC–inflammatory bowel disease and small duct phenotypes were associated with favorable prognosis (hazard ratios 0.6, 95% confidence interval 0.5‐0.9, and 0.7, 95% confidence interval 0.5‐0.96, respectively). Age, gender, and autoimmune hepatitis overlap did not impact long‐term outcome. Conclusion: PSC has a chronic, progressive course in children, and nearly half of patients develop an adverse liver outcome after 10 years of disease; elevations in bilirubin, gamma‐glutamyltransferase, and aspartate aminotransferase‐to‐platelet ratio index at diagnosis can identify patients at highest risk; small duct PSC and PSC–inflammatory bowel disease are more favorable disease phenotypes. (Hepatology 2017;66:518–527).

Challenges in meeting fellowship procedural guidelines in pediatric therapeutic endoscopy and liver biopsy

Objective: The aims of this study were to assess the opportunities for therapeutic endoscopy, liver biopsies, and percutaneous endoscopic gastrostomy (PEG) placements available to fellows during a 3-year pediatric gastroenterology fellowship, and to evaluate access to ancillary procedural-training opportunities. Methods: Data were collected from 12 pediatric gastroenterology fellowship programs in the United States. Procedures completed in the years 2009–2011 were queried using CPT codes and endoscopy databases. The maximal opportunity for procedures was based on the total procedures performed by the institution in 3 years divided by the total number of fellows in the program. The centers completed a questionnaire regarding ancillary opportunities for endoscopic training. Results: There is significant variability in pediatric endoscopic training opportunities in specialized gastrointestinal (GI) procedures. Under the 1999 guidelines, no centers were able to meet the thresholds for polypectomy and control of nonvariceal bleeding. The 2013 guidelines allowed the number of programs reaching polypectomy thresholds to increase by 67% but made no difference for control of bleeding despite a decrease in the threshold. Training in PEG placement was not available in 42% of the surveyed centers. Elective ancillary procedural training is offered by 92% of the surveyed centers. Conclusions: Most training programs do not have the volume of therapeutic endoscopy procedures for all of the fellows to meet the training guidelines. Training in therapeutic endoscopy, PEG placement, and liver biopsy in pediatric GI fellowships should be supplemented using all of the possible options including rotations with adult GI providers and hands-on endoscopy courses. A shift toward evaluating competency via quality measures may be more appropriate.

Human Parechovirus as a Cause of Isolated Pediatric Acute Liver Failure

Among infants, almost half of acute liver failure cases are classified as indeterminate, whereas only a small number of cases show a documented viral infection. We present the first reported case of isolated acute hepatic failure in an infant in the setting of a human parechovirus (HPeV) infection. HPeV also may have been contributory to the posttransplant complication of 2 intussusceptions. This is a 10-month-old girl who presented with only symptoms of fussiness and was noted to have progressive decline in synthetic liver function as well as worsening coagulopathy requiring a liver transplant. The acute liver failure was in the setting of a positive serum RNA HPeV, subtype 3 (HPeV-3), after extensive diagnostic testing with genetic, autoimmune, and infectious causes otherwise negative. After liver transplantation, the postoperative course was complicated by both an ileal-ileal intussusception as well as a jejunal intussusception. Viral testing in pediatric acute liver failure is often performed, but the workup is frequently incomplete. This case report would support more extensive viral testing in this population of patients. In the setting of HPeV, clinicians could be alerted to the possibility of delayed gastrointestinal pathology in the posttransplant phase. Wider use of routine HPeV testing may more clearly define the variable clinical presentations and outcomes.

Transabdominal Intrapericardial Approach In Liver Transplantation For Unresectable Primary Hepatic Functioning Paraganglioma With Invasion Into Hepatic Veins And Suprahepatic Vena Cava: A Surgical And Anesthesia Management Challenge

Primary hepatic functional paraganglioma is a rare form of extra-adrenal catecholamine-secreting tumor. Definitive treatment of functioning paraganglioma is challenging because of the critical location of the tumor frequently in close proximity to vital structures and risk of excessive catecholamine release during operative manipulation. We report the multidisciplinary management approach for a case of unresectable primary hepatic functional paraganglioma with invasion into the hepatic veins and suprahepatic vena cava. To our knowledge, this is the first report showing that orthotopic liver transplantation is curative for patients with unresectable primary hepatic paraganglioma. For locally advanced unresectable hepatic paraganglioma that involves the intrapericardial vena cava, a meticulous pre- and intraoperative medical management and transabdominal intrapericardial vascular control of the suprahepatic vena cava during orthotopic liver transplantation allows for complete extirpation of the tumor and achieves optimal outcome.

Staged biliary reconstruction after liver transplantation: A novel surgical strategy for high acuity pediatric transplant recipients

Introduction: Biliary complications after pediatric orthotopic liver transplantation remain causes of significant patient morbidity. Staged operative approach in complex hepatobiliary surgery has improved postoperative outcomes but has not been evaluated in pediatric orthotopic liver transplantation. We sought to analyze the outcomes of staged biliary reconstruction after orthotopic liver transplantation in high acuity patients. Methods: A retrospective analysis of 43 pediatric orthotopic liver transplantations at our center (January 2013 through December 2017). Median follow‐up was 25 months. Variables were compared for group I: 1‐stage orthotopic liver transplantation with biliary anastomosis (n = 6) versus group II: staged biliary reconstruction orthotopic liver transplantation (n = 37). Results: Comparing groups I and II, median age (7.3 vs 4.8 years), weight (27 vs 19 kg), proportion of urgent orthotopic liver transplantation (50% vs 65%), partial graft orthotopic liver transplantation (33% vs 35%), and intraoperative red blood cell transfusion volume (11 vs 21 mL/kg) were comparable. Roux‐en‐Y hepaticojejunostomy was performed in 67% (group I) and 49% (group II). There was no biliary complication in both groups. For groups I and II, 3‐year survival rates for graft (100% vs 92%, P = .477) and patient (100% vs 97%, P = .679) were comparable. Conclusion: Our study showed excellent outcomes with staged biliary reconstruction orthotopic liver transplantation in high acuity pediatric transplant recipients. This is the first report showing clinical applicability of staged biliary reconstruction orthotopic liver transplantation in children.

Perioperative anticoagulation practices for pediatric liver transplantation

Despite continued advancements in perioperative care for pediatric liver transplant (LT), graft‐threatening vascular occlusion events including hepatic artery thrombosis (HAT) and portal vein thrombosis (PVT) remain a source of significant morbidity and mortality. Perioperative anticoagulation is commonly used for the prevention of HAT and PVT, but evidence‐based guidelines are lacking. The goals of this survey were to determine the frequency of use of an anticoagulation protocol and to describe variation in anticoagulation practices among pediatric LT centers. The study consisted of an online survey distributed to members of SPLIT. The survey focused on institutional anticoagulation practices employed to reduce the incidence of graft and life‐threatening vascular occlusion events. Responses were received from 31 of 39 SPLIT centers. All respondents report using anticoagulation after pediatric LT, and approximately 90% have institutional anticoagulation protocols. Subgroup analysis of high volume pediatric LT centers revealed similar variability in anticoagulation patterns. All participating SPLIT centers reported the use of post‐transplant anticoagulation and nearly all use a protocol. However, there is marked variability in the type and dose of anticoagulation as well as the timing of initiation and duration of therapy across centers.

Gamma Glutamyltransferase Reduction Is Associated With Favorable Outcomes in Pediatric Primary Sclerosing Cholangitis

Adverse clinical events in primary sclerosing cholangitis (PSC) happen too slowly to capture during clinical trials. Surrogate endpoints are needed, but no such validated endpoints exist for children with PSC. We evaluated the association between gamma glutamyltransferase (GGT) reduction and long‐term outcomes in pediatric PSC patients. We evaluated GGT normalization (< 50 IU/L) at 1 year among a multicenter cohort of children with PSC who did or did not receive treatment with ursodeoxycholic acid (UDCA). We compared rates of event‐free survival (no portal hypertensive or biliary complications, cholangiocarcinoma, liver transplantation, or liver‐related death) at 5 years. Of the 287 children, mean age of 11.4 years old, UDCA was used in 81% at a mean dose of 17 mg/kg/day. Treated and untreated groups had similar GGT at diagnosis (314 versus 300, P= not significant [NS]). The mean GGT was reduced at 1 year in both groups, with lower values seen in treated (versus untreated) patients (99 versus 175, P= 0.002), but 5‐year event‐free survival was similar (74% versus 77%, P= NS). In patients with GGT normalization (versus no normalization) by 1 year, regardless of UDCA treatment status, 5‐year event‐free survival was better (91% versus 67%, P< 0.001). Similarly, larger reduction in GGT over 1 year (> 75% versus < 25% reduction) was also associated with improved outcome (5‐year event‐free survival 88% versus 61%, P= 0.005). Conclusion:A GGT < 50 and/or GGT reduction of > 75% by 1 year after PSC diagnosis predicts favorable 5‐year outcomes in children. GGT has promise as a potential surrogate endpoint in future clinical trials for pediatric PSC.