Management of undifferentiated embryonal sarcoma of the liver: A Pediatric Surgical Oncology Research Collaborative study.

BACKGROUND: Undifferentiated embryonal sarcoma of the liver (UESL) is a rare tumor for which there are few evidence-based guidelines. The aim of this study was to define current management strategies and outcomes for these patients using a multi-institutional dataset curated by the Pediatric Surgical Oncology Research Collaborative. METHODS: Data were collected retrospectively for patients with UESL treated across 17 children's hospitals in North America from 1989 to 2019. Factors analyzed included patient and tumor characteristics, PRETEXT group, operative details, and neoadjuvant/adjuvant regimens. Event-free and overall survival (EFS, OS) were the primary and secondary outcomes, respectively. RESULTS: Seventy-eight patients were identified with a median age of 9.9 years [interquartile range [IQR): 7-12]. Twenty-seven patients underwent resection at diagnosis, and 47 patients underwent delayed resection, including eight liver transplants. Neoadjuvant chemotherapy led to a median change in maximum tumor diameter of 1.6 cm [IQR: 0.0-4.4] and greater than 90% tumor necrosis in 79% of the patients undergoing delayed resection. R0 resections were accomplished in 63 patients (81%). Univariate analysis found that metastatic disease impacted OS, and completeness of resection impacted both EFS and OS, while multivariate analysis revealed that R0 resection was associated with decreased expected hazards of experiencing an event [hazard ratio (HR): 0.14, 95% confidence interval (CI): 0.04-0.6]. At a median follow-up of 4 years [IQR: 2-8], the EFS was 70.0% [95% CI: 60%-82%] and OS was 83% [95% CI: 75%-93%]. CONCLUSION: Complete resection is associated with improved survival for patients with UESL. Neoadjuvant chemotherapy causes minimal radiographic response, but significant tumor necrosis.

A History of Umbilical Vein Catheterization Does Not Preclude Children from a Successful Meso-Rex Bypass.

INTRODUCTION: Umbilical vein catheterization (UVC) can cause portal venous thrombosis, leading to the development of extrahepatic portal venous obstruction (EHPVO) and portal hypertension (PHT). The feasibility of the Meso-Rex bypass (MRB) for the treatment of EHPVO in patients with a history of UVC has been questioned. We compared the feasibility of performing an MRB in patients with or without a history of previous UVC. METHODS: A retrospective review of patients with EHPVO and known UVC status explored for a possible MRB at our institution was performed (1997-2022). Patients were categorized in two groups: with (UVC(+)) or without (UVC(-)) a history of UVC for comparison. A p-value less than 0.05 was considered significant. RESULTS: One hundred and eighty-seven patients were included (n = 57 in UVC(+); n = 130 in UVC(-)). Patients in the UVC group were significantly younger at surgery and the incidence of prematurity was higher. Other risk factors for the development of EHPVO were similar between the groups, but only history of UVC could predict the ability to receive MRB (odds ratio [OR]: 7.4 [3.5-15.4]; p < 0.001). The success rate of MRB was significantly higher in patients with no history of UVC (28/57 [49.1%] in UVC(+) vs. 114/130 [87.7%] in UVC(-); p < 0.001). However, MRB patency at discharge (25/28 [89.3%] in UVC(+) vs. 106/114 [94.7%] in UVC(-); p = 0.3) was equally high in both groups. CONCLUSION: Our results indicate that a history of UVC is not a contraindication to MRB. Half of the patients were able to successfully receive an MRB. Patients with symptomatic PHT from EHPVO should not be excluded from consideration for MRB based on UVC history.

Critical elements of pediatric liver cancer surgery.

The appropriate management of pediatric liver malignancies, primarily hepatoblastoma and hepatocellular carcinoma, requires an in depth understanding of contemporary preoperative risk stratification, experience with advanced hepatobiliary surgery, and a good relationship with one's local or regional liver transplant center. While chemotherapy regimens have become more effective, operative indications more well-defined, and overall survival improved, the complexity of liver surgery in small children provides ample opportunity for protocol violation, inadequate resection, and iatrogenic morbidity. These guidelines represent the distillation of contemporary literature and expert opinion as a means to provide a framework for preoperative planning and intraoperative decision-making for the pediatric surgeon.

Overview of pediatric kidney transplantation.

Kidney transplantation is the treatment of choice for pediatric patients with end-stage kidney disease. Unlike adult recipients undergoing transplantation, special considerations must be taken when transplanting children based on the underlying etiology of kidney disease, previous surgical procedures, anatomical limitations and necessary technical adjustments. Additionally, the choice of donor must be measured to ensure optimal graft survival given a longer post-transplant life expectancy. Those topics as well as frequently encountered postoperative complications are also discussed in this publication.

Histologic type predicts disparate outcomes in pediatric hepatocellular neoplasms: A Pediatric Surgical Oncology Research Collaborative study.

BACKGROUND: Hepatocellular carcinoma (HCC) is a rare cancer in children, with various histologic subtypes and a paucity of data to guide clinical management and predict prognosis. METHODS: A multi-institutional review of children with hepatocellular neoplasms was performed, including demographic, staging, treatment, and outcomes data. Patients were categorized as having conventional HCC (cHCC) with or without underlying liver disease, fibrolamellar carcinoma (FLC), and hepatoblastoma with HCC features (HB-HCC). Univariate and multivariate analyses identified predictors of mortality and relapse. RESULTS: In total, 262 children were identified; and an institutional histologic review revealed 110 cHCCs (42%; 69 normal background liver, 34 inflammatory/cirrhotic, 7 unknown), 119 FLCs (45%), and 33 HB-HCCs (12%). The authors observed notable differences in presentation and behavior among tumor subtypes, including increased lymph node involvement in FLC and higher stage in cHCC. Factors associated with mortality included cHCC (hazard ratio [HR], 1.63; P = .038), elevated α-fetoprotein (HR, 3.1; P = .014), multifocality (HR, 2.4; P < .001), and PRETEXT (pretreatment extent of disease) stage IV (HR, 5.76; P < .001). Multivariate analysis identified increased mortality in cHCC versus FLC (HR, 2.2; P = .004) and in unresectable tumors (HR, 3.4; P < .001). Disease-free status at any point predicted survival. CONCLUSIONS: This multi-institutional, detailed data set allowed a comprehensive analysis of outcomes for children with these rare hepatocellular neoplasms. The current data demonstrated that pediatric HCC subtypes are not equivalent entities because FLC and cHCC have distinct anatomic patterns and outcomes in concert with their known molecular differences. This data set will be further used to elucidate the impact of histology on specific treatment responses, with the goal of designing risk-stratified algorithms for children with HCC. LAY SUMMARY: This is the largest reported granular data set on children with hepatocellular carcinoma. The study evaluates different subtypes of hepatocellular carcinoma and identifies key differences between subtypes. This information is pivotal in improving understanding of these rare cancers and may be used to improve clinical management and subsequent outcome in children with these rare malignancies.

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.

Mutation Analysis and Disease Features at Presentation in a Multi-Center Cohort of Children With Monogenic Cholestasis.

OBJECTIVES: To advance our understanding of monogenic forms of intrahepatic cholestasis. METHODS: Analyses included participants with pathogenic biallelic mutations in adenosine triphosphate (ATP)-binding cassette subfamily B member 11 (ABCB11) (bile salt export pump; BSEP) or adenosine triphosphatase (ATPase) phospholipid transporting 8B1 (ATP8B1) (familial intrahepatic cholestasis; FIC1), or those with monoallelic or biallelic mutations in adenosine triphosphate (ATP)-binding cassette subfamily B member 4 (ABCB4) (multidrug resistance; MDR3), prospectively enrolled in the Longitudinal Study of Genetic Causes of Intrahepatic Cholestasis (LOGIC; NCT00571272) between November 2007 and December 2013. Summary statistics were calculated to describe baseline demographics, history, anthropometrics, laboratory values, and mutation data. RESULTS: Ninety-eight participants with FIC1 (n = 26), BSEP (n = 53, including 8 with biallelic truncating mutations [severe] and 10 with p.E297G or p.D482G [mild]), or MDR3 (n = 19, including four monoallelic) deficiency were analyzed. Thirty-five had a surgical interruption of the enterohepatic circulation (sEHC), including 10 who underwent liver transplant (LT) after sEHC. Onset of symptoms occurred by age 2 years in most with FIC1 and BSEP deficiency, but was later and more variable for MDR3. Pruritus was nearly universal in FIC1 and BSEP deficiency. In participants with native liver, failure to thrive was common in FIC1 deficiency, high ALT was common in BSEP deficiency, and thrombocytopenia was common in MDR3 deficiency. sEHC was successful after more than 1 year in 7 of 19 participants with FIC1 and BSEP deficiency. History of LT was most common in BSEP deficiency. Of 102 mutations identified, 43 were not previously reported. CONCLUSIONS: In this cohort, BSEP deficiency appears to be correlated with a more severe disease course. Genotype-phenotype correlations in these diseases are not straightforward and will require the study of larger cohorts.

Pancreaticoduodenectomy for the treatment of pancreatic neoplasms in children: A Pediatric Surgical Oncology Research Collaborative study.

BACKGROUND: To better characterize short-term and long-term outcomes in children with pancreatic tumors treated with pancreaticoduodenectomy (PD). METHODS: Patients 21 years of age or younger who underwent PD at Pediatric Surgical Oncology Collaborative (PSORC) hospitals between 1990 and 2017 were identified. Demographic, clinical information, and outcomes (operative complications, long-term pancreatic function, recurrence, and survival) were collected. RESULTS: Sixty-five patients from 18 institutions with a median age of 13 years (4 months-22 years) and a median (IQR) follow-up of 2.8 (4.3) years were analyzed. Solid pseudopapillary tumor of the pancreas (SPN) was the most common histology. Postoperative complications included pancreatic leak in 14% (n = 9), delayed gastric emptying in 9% (n = 6), marginal ulcer in one patient, and perioperative (30-day) death due to hepatic failure in one patient. Pancreatic insufficiency was observed in 32% (n = 21) of patients, with 23%, 3%, and 6% with exocrine, or endocrine insufficiencies, or both, respectively. Children with SPN and benign neoplasms all survived. Overall, there were 14 (22%) recurrences and 11 deaths (17%). Univariate analysis revealed non-SPN malignant tumor diagnosis, preoperative vascular involvement, intraoperative transfusion requirement, pathologic vascular invasion, positive margins, and need for neoadjuvant chemotherapy as risk factors for recurrence and poor survival. Multivariate analysis only revealed pathologic vascular invasion as a risk factor for recurrence and poor survival. CONCLUSION: This is the largest series of pediatric PD patients. PD is curative for SPN and benign neoplasms. Pancreatic insufficiency is the most common postoperative complication. Outcome is primarily associated with histology.

MR angiography and 2-D phase-contrast imaging for evaluation of meso-rex bypass function.

BACKGROUND: The meso-Rex bypass restores blood flow to the liver in patients with extrahepatic portal vein thrombosis. Stenosis occurs in some cases, causing the reappearance of portal hypertension. Complications such as thrombocytopenia present on a spectrum and there are currently no guidelines regarding a threshold for endovascular intervention. While Doppler ultrasound (US) is common for routine evaluation, magnetic resonance (MR) angiography with two-dimensional phase-contrast MRI (2-D PC-MRI) may improve the assessment of meso-Rex bypass function. OBJECTIVES: To determine the feasibility and utility of MR angiography with 2-D PC-MRI in evaluating children with meso-Rex bypass and to correlate meso-Rex bypass blood flow to markers of portal hypertension. MATERIALS AND METHODS: MR angiography and 2-D PC-MRI in meso-Rex bypass patients were retrospectively analyzed. Minimum bypass diameter was measured on MR angiography and used to calculate cross-sectional area. Meso-Rex bypass blood flow was measured using 2-D PC-MRI and divided by ascending aortic flow to quantify bypass flow relative to systemic circulation. Platelet and white blood cell counts were recorded. Correlation was performed between minimum bypass area, blood flow and clinical data. RESULTS: Twenty-five children (median age: 9.5 years) with meso-Rex bypass underwent MR angiography and 2-D PC-MRI. The majority of patients were referred to imaging given clinical concern for complications. Eighteen of the 25 patients demonstrated >50% narrowing of the bypass cross-sectional area. The mean platelet count in 19 patients was 127 K/µL. There was a significant correlation between minimum cross-sectional bypass area and bypass flow (rho=0.469, P=0.018) and between bypass flow and platelet counts (r=0.525, P=0.021). CONCLUSION: Two-dimensional PC-MRI can quantify meso-Rex bypass blood flow relative to total systemic flow. In a cohort of 25 children, bypass flow correlated to minimum bypass area and platelet count. Two-dimensional PC-MRI may be valuable alongside MR angiography to assess bypass integrity.

Metabolic profile of children with extrahepatic portal vein obstruction undergoing meso-Rex bypass.

BACKGROUND: Extrahepatic portal vein obstruction (EHPVO) in children is often associated with growth restriction, which improves after the restoration of portal venous flow with a meso-Rex bypass, but the physiologic mechanism is unknown. The purpose of this study was to investigate the mechanism of growth delay in children with EHPVO by detailing the metabolic and nutritional profile before and after meso-Rex bypass. METHODS: Twenty consecutive children with EHPVO were prospectively studied before and 1 year after meso-Rex bypass. Caloric balance was determined by investigating caloric intake via a calorie count, total energy expenditure via a doubly labeled water isotope assay and stool caloric loss by bomb calorimetry. Laboratory markers of nutrition and growth hormone resistance were tested. RESULTS: Fifteen of the 20 children underwent successful meso-Rex bypass at a median age of 4.3 years. Prealbumin level was abnormally low (14.6 ± 3.0 mg/dL) at surgery but improved (17.0 ± 4.3 mg/dL) 1 year later (P = 0.026). Mean insulin-like growth factor 1 (IGF-1) level at baseline was 1.57 standard deviations below normal. IGF-1 levels increased from 88.3 ± 38.9 to 117.3 ± 54.5 ng/mL in the year after surgery (P = 0.047). Caloric intake divided by basal metabolic rate (1.90 ± 0.61), total energy expenditure (97.2 ± 15.0% of expected), and stool caloric losses (3.7 ± 1.8% of caloric intake) were all normal at baseline. CONCLUSIONS: Children with EHPVO suffer from malnutrition and growth hormone resistance, which may explain their well-established finding of growth restriction. Prealbumin and IGF-1 levels improve after a successful meso-Rex bypass.

Outcomes following partial external biliary diversion in patients with progressive familial intrahepatic cholestasis.

BACKGROUND/PURPOSE: PFIC is a family of bile acid (BA) transport disorders that may result in serious liver disease requiring transplantation. We reviewed our experience with PEBD as a method to improve liver function and avoid transplantation. METHODS: All patients with PFIC were reviewed. Outcomes included changes in serum BA, conversion to ileal bypass (IB), and survival without transplantation. Statistics were obtained using paired t-test and Wilcoxon test. RESULTS: Thirty-five patients with PFIC were identified. Data were available in 24. Twenty-four children (12 males) underwent PEBD: 10 PFIC-1, 13 PFIC-2, and one PFIC-3. BA levels decreased in PFIC-1 patients (1724±3215 to 11±6µmol/L, P=0.03) and in the single PFIC-3 patient (821 to 11.2µmol/L), but not significantly in PFIC-2 patients (193±99 to 141±118µmol/L, P=0.15). Seven patients were converted to IB. There were no significant changes in BA levels following conversion. Five-year transplant-free survival was 100% in PFIC-1 and PFIC-3, but only 38% (5/13) in PFIC-2 (P=0.004). CONCLUSION: PEBD is an effective procedure to reduce total BA levels and improve symptoms in PFIC patients. However, it appears to be less efficacious in the PFIC-2 group. The higher BA levels could contribute to ongoing liver damage, and thus a higher transplant rate in PFIC-2 patients. LEVEL OF EVIDENCE: Level IV.

Hepatoblastoma in Children With Congenital Portosystemic Shunts.

Two children developed hepatoblastoma concurrent with congenital portosystemic shunts (PSSs) (Abernethy malformations). Both underwent operative ligation of their PSSs. One received concurrent tumor resection, whereas the other was deemed initially unresectable and underwent biopsy followed by neoadjuvant chemotherapy. Although benign hepatic masses, such as focal nodular hyperplasia and nodular regenerative hyperplasia, are common in patients with Abernethy malformations, malignant tumors have also been documented and should always be considered in the differential diagnosis of a patient with a congenital PSS and a hepatic mass.

Predictors of Enteral Autonomy in Children with Intestinal Failure: A Multicenter Cohort Study.

OBJECTIVES: In a large cohort of children with intestinal failure (IF), we sought to determine the cumulative incidence of achieving enteral autonomy and identify patient and institutional characteristics associated with enteral autonomy. STUDY DESIGN: A multicenter, retrospective cohort analysis from the Pediatric Intestinal Failure Consortium was performed. IF was defined as severe congenital or acquired gastrointestinal diseases during infancy with dependence on parenteral nutrition (PN) >60 days. Enteral autonomy was defined as PN discontinuation >3 months. RESULTS: A total of 272 infants were followed for a median (IQR) of 33.5 (16.2-51.5) months. Enteral autonomy was achieved in 118 (43%); 36 (13%) remained PN dependent and 118 (43%) patients died or underwent transplantation. Multivariable analysis identified necrotizing enterocolitis (NEC; OR 2.42, 95% CI 1.33-4.47), care at an IF site without an associated intestinal transplantation program (OR 2.73, 95% CI 1.56-4.78), and an intact ileocecal valve (OR 2.80, 95% CI 1.63-4.83) as independent risk factors for enteral autonomy. A second model (n = 144) that included only patients with intraoperatively measured residual small bowel length found NEC (OR 3.44, 95% CI 1.36-8.71), care at a nonintestinal transplantation center (OR 6.56, 95% CI 2.53-16.98), and residual small bowel length (OR 1.04 cm, 95% CI 1.02-1.06 cm) to be independently associated with enteral autonomy. CONCLUSIONS: A substantial proportion of infants with IF can achieve enteral autonomy. Underlying NEC, preserved ileocecal valve, and longer bowel length are associated with achieving enteral autonomy. It is likely that variations in institutional practices and referral patterns also affect outcomes in children with IF.

A case series of congenital hepatic hilar cyst: recommendations for diagnosis and management.

BACKGROUND: Congenital hepatic hilar cysts are rare. Some are simple and do not require intervention, but some biliary cystic malformations impose the risk of morbidity and mortality. OBJECTIVES: To assess a series of five patients presenting with congenital hepatic hilar cysts. METHODS: We retrospectively reviewed all cases presenting to our pediatric surgical service between January 2010 and December 2012 and found to have a congenital hepatic hilar cyst. Data regarding clinical, radiological, operative and pathological features were analyzed. RESULTS: Five children with congenital cyst of the hepatic hilum were identified; four of them were diagnosed prenatally. Four children had undergone surgical intervention: one with intrahepatic choledochal cyst, one with epidermoid cyst, and two with biliary atresia and an associated cyst of the common bile duct. In another case of choledochal cyst the treatment was conservative. All children except one had a good prognosis; one child with biliary atresia required liver transplantation. CONCLUSIONS: The differential diagnosis of congenital hepatic hilar cyst includes a broad spectrum of pathologies. It is essential to diagnose biliary atresia as early as possible. Signs such as smaller cysts in association with a hypoplastic gallbladder and direct hyperbilirubinemia may be suggestive of biliary atresia.

Perioperative strategies and thrombophilia in children with extrahepatic portal vein obstruction undergoing the meso-Rex bypass.

BACKGROUND/PURPOSE: Extrahepatic portal vein obstruction (EHPVO) is an important cause of chronic portal hypertension in children. Although usually idiopathic in etiology, genetic and acquired thrombophilia have been implicated in EHPVO. Meso-Rex bypass is increasingly used to treat EHPVO in children. OBJECTIVE: The objective of this study is to assess the relationship of postoperative anticoagulation strategies and thrombophilic risk factors to the development of bypass thrombosis following the meso-Rex bypass. METHODS: Records of children who underwent meso-Rex bypass for EHPVO at a single institution from 1999 to 2009 were reviewed, and preoperative thrombophilia testing, perioperative anticoagulation strategies, and postoperative bypass patency based on imaging at last follow-up were examined. RESULTS: Sixty-five children with EHPVO underwent a first time meso-Rex bypass during the study period, and 9 of 65 (14 %) developed bypass thrombosis. The use of warfarin in the postoperative period was more common among children with thrombosed shunts than among those with open shunts [63 % vs. 20 %; OR, 6.5 (95 % CI, 1.3-31.5), p = 0.022]. The contribution of genetic or acquired thrombophilia to shunt thrombosis was inconclusive given variability in testing. CONCLUSIONS: Choice of anticoagulation following meso-Rex bypass may affect postoperative incidence of bypass thrombosis. Role of thrombophilic risk factors in the development of shunt thrombosis remains unclear.

Advantages of the meso-Rex bypass compared with portosystemic shunts in the management of extrahepatic portal vein obstruction in children.

BACKGROUND: Consequences of extrahepatic portal vein obstruction (EHPVO) include variceal bleeding and hypersplenism due to portal hypertension, as well as metabolic abnormalities secondary to impaired portal venous circulation. The purpose of this study was to compare the effectiveness of meso-Rex bypass and portosystemic shunt (PSS) for reversing these symptoms in children with EHPVO. STUDY DESIGN: All children with idiopathic EHPVO evaluated for potential meso-Rex bypass at a single institution between 1997 and 2010 were reviewed. Portosystemic shunt was performed in patients with refractory portal hypertension when meso-Rex bypass was not technically feasible. Outcomes of meso-Rex bypass and PSS were compared, including resolution of portal hypertensive bleeding and hypersplenism, as well as changes in liver synthetic function, ammonia levels, and somatic growth. RESULTS: Sixty-five children with EHPVO underwent successful meso-Rex bypass, while 16 required PSS. Nearly all patients experienced complete relief of variceal bleeding after meso-Rex (96%) bypass and PSS (100%). The improvements in platelet count (+82.1 ± 60.0 vs +32.4 ± 56.3 thousand/µL; p=0.004), internal normalized ratio (-0.22 ± 0.27 vs 0.01 ± 0.14; p=0.022), and serum ammonia level (-26.8 ± 36.8 vs +19.4 ± 33.1 µM/L; p=0.002) were greater after meso-Rex bypass than PSS. Among patients with below average (standard deviation z-score<0) preoperative weight for age, the improvement in weight-for-age z-score was greater after meso-Rex bypass (+0.84 ± 0.98) than PSS (+0.17 ± 0.79, p=0.044). Median duration of follow-up was 4.45 years after meso-Rex bypass and 1.8 years after PSS. CONCLUSIONS: Both meso-Rex bypass and PSS effectively relieve symptoms of portal hypertensive bleeding in children with EHPVO, although the meso-Rex better relieves hypersplenism. By restoring normal portal venous circulation, the meso-Rex bypass has additional metabolic benefits.