Impact of Portal Flow on the Prognosis of Children With Congenital Portosystemic Shunt: A Multicentric Observation Study in Japan.

BACKGROUND: Although congenital portosystemic shunts (CPSSs) are increasingly being recognized, the optimal treatment strategies and natural prognosis remain unclear, as individual CPSSs show different phenotypes. METHODS: The medical records of 122 patients who were diagnosed with CPSSs at 15 participating hospitals in Japan between 2000 and 2019 were collected for a retrospective analysis based on the state of portal vein (PV) visualization on imaging. RESULTS: Among the 122 patients, 75 (61.5%) showed PV on imaging. The median age at the diagnosis was 5 months. The main complications related to CPSS were hyperammonemia (85.2%), liver masses (25.4%), hepatopulmonary shunts (13.9%), and pulmonary hypertension (11.5%). The prevalence of complications was significantly higher in patients without PV visualization than in those with PV visualization (P < 0.001). Overall, 91 patients (74.6%) received treatment, including shunt closure by surgery or interventional radiology (n = 82) and liver transplantation (LT) or liver resection (n = 9). Over the past 20 years, there has been a decrease in the number of patients undergoing LT. Although most patients showed improvement or reduced progression of symptoms, liver masses and pulmonary hypertension were less likely to improve after shunt closure. Complications related to shunt closure were more likely to occur in patients without PV visualization (P = 0.001). In 25 patients (20.5%) without treatment, those without PV visualization were significantly more likely to develop complications related to CPSS than those with PV visualization (P = 0.011). CONCLUSION: Patients without PV visualization develop CPSS-related complications and, early treatment using prophylactic approaches should be considered, even if they are asymptomatic. LEVEL OF EVIDENCE: Level III.

The Association between the First Cry and Clinical Outcomes in CDH Neonates: A Retrospective Study.

Congenital diaphragmatic hernia (CDH) is a life-threatening condition characterized by the herniation of abdominal organs into the thorax, resulting in hypoplastic lungs and pulmonary hypertension. The impact of the first cry, a crucial event for lung transition during birth, on CDH patients remains unclear. This study investigated the impact of the first cry during birth on CDH patient survival, along with other prognosis factors. A multi-institutional retrospective study assessed CDH patient characteristics and survival rates by analyzing factors including the first cry, disease severity, birth weight, Apgar scores, oxygenation index (OI) and surgical closure. Among the CDH patients in the study, a positive first cry was linked to 100% survival, regardless of disease severity (p < 0.001). Notably, the presence of a positive first cry did not significantly affect survival rates in patients with worse prognostic factors, such as low birth weight (<2500 g), high CDH severity, low Apgar scores (1 min ≤ 4), high best OI within 24 h after birth (≥8), or those who underwent patch closure. Furthermore, no significant association was found between the first cry and the use of inhaled nitric oxide (iNO) or extracorporeal membrane oxygenation (ECMO). In conclusion, this study suggests that the first cry may not have a negative impact on the prognosis of CDH patients and could potentially have a positive effect.

Case report: Hepatectomy with Rex bypass for a child with hepatoblastoma and portal vein thrombosis.

Pediatric liver tumors with portal vein obstruction are often candidates for liver transplantation. However, lifelong use of immunosuppressants and invasiveness to healthy donors in the case of living-donor liver transplantation is inevitable. Moreover, when lung metastasis is involved, the lung recurrence rate after liver transplantation is still high. Therefore, transplantation should be avoided as much as possible. In cases of tumors in the right lobe of the liver, complete resection of the portal vein trunk may be possible by creating a Rex bypass, but with the original method, end-to-side anastomosis to the umbilical portal vein is difficult in small children. We report a case of a 2-year-old girl with hepatoblastoma in whom a Rex shunt was created by end-to-end anastomosing the recanalized umbilical vein to the portal vein stump with interposing a vein graft, and the right lobe was successfully resected along with the tumor.

Right to left ventricular volume ratio is associated with mortality in congenital diaphragmatic hernia.

BACKGROUND: Congenital diaphragmatic hernia (CDH) is associated with high neonatal mortality. We performed this study to test the hypothesis that left ventricular (LV) and right ventricular (RV) volumes assessed by three-dimensional echocardiography may be associated with mortality in CDH. METHODS: This study was a single-center retrospective cohort study involving 35 infants with CDH. RV and LV end-diastolic volume (RVEDV and LVEDV, respectively) were measured by three-dimensional echocardiography and were corrected by birth body weight (BBW) on day 1. RVEDV/BBW, LVEDV/BBW, and LVEDV/RVEDV were compared between CDH survivors and non-survivors. Receiver-operating characteristic curve analysis was performed to assess the predictive ability for mortality of the echocardiographic parameters. RESULTS: Comparing CDH non-survivors (n = 6) with survivors (n = 29), respectively, RVEDV/BBW was significantly larger (2.54 ± 0.33 vs 1.86 ± 0.35 ml/kg; P < 0.01), LVEDV/BBW was significantly smaller (0.86 ± 0.21 vs 1.22 ± 0.33 ml/kg; P < 0.001), and LVEDV/RVEDV was significantly lower (0.34 ± 0.06 vs 0.66 ± 0.18; P < 0.001). The area under the curve for LVEDV/RVEDV was the largest (0.98). CONCLUSIONS: Three-dimensional echocardiographic volume imbalance between the RV and LV was remarkable in CDH non-survivors. The LVEDV/RVEDV ratio may be associated with mortality in CDH. IMPACT: Mortality with congenital diaphragmatic hernia (CDH) is high, and evaluating left and right ventricular structures and functions may be helpful in assessing the prognosis. Three-dimensional (3D) echocardiography indicated that the left ventricular end-diastolic volume/right ventricular end-diastolic volume ratio within 24 h after birth was associated with mortality in CDH infants. The usefulness of this ratio should be validated in prospective multicenter studies involving larger numbers of patients.

Infantile hepatic hemangioma and hepatic mesenchymal hamartoma in an infant associated with placental mesenchymal dysplasia: a case report.

BACKGROUND: Although infantile hepatic hemangioma and hepatic mesenchymal hamartoma are relatively common in benign pediatric liver tumors, coexistence of the two tumors is rare. Placental mesenchymal dysplasia is also a rare disorder. We report the case of a baby girl born after a pregnancy complicated by placental mesenchymal dysplasia, who developed both infantile hepatic hemangioma and hepatic mesenchymal hamartoma. CASE PRESENTATION: The patient was born at 32 weeks and 5 days of gestation for impending placental abruption, weighing 1450 g. Liver tumors, composed of both hypervascular solid and large cystic lesions, were detected after birth and markedly increased to create abdominal distention within 9 months. Diagnostic imaging suspected the coexistence of infantile hepatic hemangioma and cystic hepatic mesenchymal hamartoma. Following propranolol therapy for infantile hepatic hemangioma and needle puncture of a large cyst, the cystic lesions and adjacent hypervascular lesions were partially resected via laparotomy. Pathological findings confirmed the coexistence of hepatic mesenchymal hamartoma and infantile hepatic hemangioma, which had no association with androgenetic/biparental mosaicism. The postoperative course was uneventful, and the tumor had not regrown after 3 years. CONCLUSIONS: Although the coexistence of infantile hepatic hemangioma and hepatic mesenchymal hamartoma associated with placental mesenchymal dysplasia is extremely rare, the pathological and pathogenetic similarities between these disorders suggest that they could have derived from similar embryologic origins rather than being a mere coincidence. Further follow-up is required, with careful attention to the potential for malignant hepatic mesenchymal hamartoma transformation.

A novel risk stratification model based on the Children's Hepatic Tumours International Collaboration-Hepatoblastoma Stratification and deoxyribonucleic acid methylation analysis for hepatoblastoma.

INTRODUCTION: Hepatoblastoma (HB) is the most common paediatric liver tumour, and epigenetic aberrations may be important in HB development. Recently, the Children's Hepatic Tumors International Collaboration-Hepatoblastoma Stratification (CHIC-HS) developed risk stratification based on clinicopathological factors. This study aimed to construct a more accurate model by integrating CHIC-HS with molecular factors based on DNA methylation. METHODS: HB tumour specimens (N = 132) from patients treated with the Japanese Pediatric Liver Tumors Group-2 protocol were collected and subjected to methylation analysis by bisulfite pyrosequencing. Associations between methylation status and clinicopathological factors, overall survival (OS), and event-free survival (EFS) were retrospectively analysed. We investigated the effectiveness of the evaluation of methylation status in each CHIC-HS risk group and generated a new risk stratification model. RESULTS: Most specimens (82%) were from post-chemotherapy tissue. Hypermethylation in ≥2 of the four genes (RASSF1A, PARP6, OCIAD2, and MST1R) was significantly associated with poorer OS and EFS. Multivariate analysis indicated that ≥2 methylated genes was an independent prognostic factor (hazard ratios of 6.014 and 3.684 for OS and EFS, respectively). Two or more methylated genes was also associated with poorer OS in the CHIC-very low (VL)-/low (L)-risk and CHIC-intermediate (I) risk groups (3-year OS rates were 83% vs. 98% and 50% vs. 95%, respectively). The 3-year OS rates of the VL/L, I, and high-risk groups in the new stratification model were 98%, 90%, and 62% (vs. CHIC-HS [96%, 82%, and 65%, respectively]), optimising CHIC-HS. CONCLUSIONS: Our proposed stratification system considers individual risk in HB and may improve patient clinical management.

Clinicopathological study of surgery for pulmonary metastases of hepatoblastoma with indocyanine green fluorescent imaging.

BACKGROUND: The prognosis of metastatic hepatoblastoma remains poor; to improve it, pulmonary metastasis must be controlled. Indocyanine green (ICG) fluorescent imaging has been used recently for lung metastasectomy. The objective of our study was to clarify the usefulness of ICG imaging for lung metastasectomy of hepatoblastoma using detailed clinicopathological analysis. PROCEDURE: Patients with hepatoblastoma who underwent resection of pulmonary metastases with ICG fluorescent imaging were studied using a retrospective analysis of clinical information, a review of their surgical records, and a histological analysis of their metastatic nodules. RESULTS: Sixteen patients were enrolled. In total, 61 ICG imaging-guided pulmonary metastasectomies were performed, and 350 ICG-positive and 23 ICG-negative specimens were identified. Tumors were confirmed in 250 of the ICG-positive specimens, including eight nonpalpable nodules, on microscopic examination. ICG-positive and tumor-negative specimens showed histological changes suggesting the regression of a tumor or bloodstream disturbance. CONCLUSIONS: Surgical resection is one of the few treatment strategies available to patients with hepatoblastoma with multiple relapses of pulmonary metastasis resistant to chemotherapy. This study demonstrates the high sensitivity of ICG imaging and that thorough metastasectomy can be achieved with ICG imaging. Because a number of false-positive specimens were detected, further optimization of the dose of ICG and the timing of its administration, and establishment of detection of ICG-positive, tumor-negative nodules during surgery are important issues. Several false-negative specimens were also detected, suggesting the presence of ICG-negative metastatic tumors. Palpation during surgery and imaging studies remain essential for detecting metastatic lesions, even in the era of ICG imaging.

Characteristics and treatment of congenital esophageal stenosis: A retrospective collaborative study from three Japanese children's hospitals.

BACKGROUND/PURPOSE: There is no consensus on treatment strategy of congenital esophageal stenosis (CES). This study aimed to assess appropriateness of the treatment we have provided to patients with CES over the past four decades. METHODS: We carried out a retrospective chart review of 83 CES patients treated at three children's hospitals between 1973 and 2015. Each patient underwent an initial treatment with either surgery or a series of dilation that was followed by surgery if dilation failed to improve esophageal transit. Demographic data, course of treatment, outcomes, and complications were analyzed. RESULTS: During this initial treatment, 19 and 64 patients underwent surgery and dilation, respectively. Out of the 64 patients who underwent dilations as an initial treatment, 26 patients eventually required surgery. Out of all patients who required surgery (19 initial treatments + 26 failed dilations), 29 had tracheobronchial remnants and 16 had fibromuscular hypertrophy. Six patients experienced esophageal perforation during dilation and ten experienced anastomotic leakage after surgery. No patients had swallowing difficulties at the latest follow up, 141(9-324) months. CONCLUSIONS: Dilation is recommended as an initial therapy, especially if histological diagnosis of CES is uncertain. Persistent swallowing difficulties after 2 series of dilation may be an indication for surgery. LEVELS OF EVIDENCE: level IV.

A novel method for isolating lymphatic endothelial cells from lymphatic malformations and detecting PIK3CA somatic mutation in these isolated cells.

PURPOSE: Tissue disaggregation and the cell sorting technique by surface markers has played an important role in isolating lymphatic endothelial cells (LECs) from lymphatic malformation (LM). However, this technique may have the drawback of impurities or result in isolation failure because it is dependent on surface marker expressions, the heterogeneity of which has been found in the lymphatic system. We developed a novel method for isolating LM-LECs without using whole tissue disaggregation. METHODS: Seven LM surgical specimens were collected from seven patients with LMs. LM-LECs were detached from the LM cyst wall by "lumen digestion" and irrigating the cystic cavity with trypsin, and maintained in culture. RESULTS: The cells formed a monolayer with a cobblestone-like appearance. Immunohistochemistry and quantitative RT-PCR of these cells revealed high expression of lymphatic-specific genes, confirming their identity as LM-LECs. The whole-exome sequencing and PIK3CA sequencing of these cells revealed somatic mutations in PIK3CA in all cases. CONCLUSIONS: We established a novel technique for isolating LM-LECs from LM tissue by "lumen digestion" without whole-tissue disaggregation. The limited incorporation of non-LM LECs in the isolate in our method could make it an important tool for investigating the heterogeneity of gene expression as well as mutations in LM-LECs.

A MicroRNA Cluster in the DLK1-DIO3 Imprinted Region on Chromosome 14q32.2 Is Dysregulated in Metastatic Hepatoblastomas.

Hepatoblastoma (HB) is the most common malignant liver neoplasm in children. Despite progress in HB therapy, outcomes for patients with metastatic disease remain poor. Dysregulation of miRNA expression is one of the potential epigenetic mechanisms associated with pathogenesis of HB. However, miRNA profiles related to the different stages of HB tissues and cells, in particular of lung metastatic tumor cells, are unknown. In the present study, using array-based miRNA expression and DNA methylation analysis on formalin-fixed paraffin-embedded tissues, we aimed to identify miRNA changes that can discriminate between lung metastatic tumors, primary tumors (fetal and embryonal subtypes), and nontumorous surrounding livers. Our analysis demonstrated that a large cluster of microRNAs and snoRNAs located within the 14q32.2 DLK1-DIO3 region showed a strikingly upregulated expression pattern in HB tumors, especially metastatic tumors, compared to normal liver tissues. This revealed dysregulation of miRNAs similar to that seen in a malignant stem-like subtype of hepatocellular carcinoma associated with poor prognosis. These findings in HB mirror similar findings made in multiple other cancer types. With further analysis this may in future allow stratification of different stages and types of HB tumors based on their miRNA profiles, which could lead to new approaches to diagnosis and treatment in progressive HB patients.

Lymphatic malformations compromising the upper airway in children: ultrasound-guided intralesional focal sclerotherapy with bleomycin targeting culprit lesions.

PURPOSE: Lymphatic malformations (LMs) compromising the upper airway is a life-threatening and intractable disease. Here, we establish a novel method to perform intralesional focal sclerotherapy targeting the culprit for airway stenosis. METHODS: Between July 2015 and February 2020, 11 patients with airway-compromising LMs were enrolled. To yield maximal effects on the compromised airway with minimal adverse effects, ultrasound-guided intralesional bleomycin sclerotherapy assisted by balloon was performed, aimed at the most responsible lesion around the airway. A retrospective analysis was performed. RESULTS: Ten patients presented with respiratory symptoms, eight of whom required airway support. The last asymptomatic patient showed airway compression on magnetic resonance imaging. The dose of bleomycin injected ranged from 1.3-9 mg per patient per course. A median of one course was required for withdrawal from airway support, and the median time was 15 days. A median of two courses was required to eliminate the lesion adjacent to the airway, which would have potential risk of airway stenosis. No complications were observed. CONCLUSIONS: Our intralesional focal sclerotherapy technique with bleomycin targeting the culprit lesion is dose-sparing, safe, and effective in achieving rapid shrinkage of LMs compromising the upper airway in children, thereby avoiding tracheostomy.

Liver cirrhosis in a child associated with Castleman's disease: A case report.

BACKGROUND: Castleman's disease (CD) is a lymphoproliferative disorder. TAFRO syndrome is classified as a variant of CD based on its key clinical manifestations of thrombocytopenia, anasarca (generalized edema and pleural effusion), fever (pyrexia), reticulin fibrosis in the bone marrow and the proliferation of megakaryocytes, and organomegaly (such as hepatosplenomegaly and multiple lymphadenopathies); TAFRO syndrome is mainly reported in Japanese patients. To our knowledge, this is the first pediatric case report detailing a CD-associated disorder progressing to cirrhosis. CASE SUMMARY: A 10-year old male patient presented with fever and anemia. Six months before hospitalization, he had remarkable abdominal distention. Subsequently, he visited a clinic for a fever that lasted 5 d. The physical findings were marked hepatosplenomegaly and cervical lymphadenopathy. A blood test revealed leukocytosis, microcytic anemia, aspartate aminotransferase-dominant transaminase elevation, high levels of C-reactive protein, polyclonal hypergammaglobulinemia, and high levels of interleukin-6 and vascular endothelial growth factor. Abdominal contrast computed tomography and magnetic resonance imaging suggested cirrhosis, which was confirmed by liver histology. Histological findings in the enlarged hepatic lymph nodes revealed both hyperplasia and atrophy of lymphoid follicles with some vascular hyperplasia and moderate plasmacytosis between the lymphoid follicles, which is compatible with lymph node histology in TAFRO syndrome. Prednisolone was not effective in reducing the patient's symptoms; therefore, the patient was prescribed tocilizumab. To date, the patient remains free of fever and continues to receive tocilizumab. CONCLUSION: We described the clinicopathological features of TAFRO syndrome to highlight the clinical presentation of this rare disease in a pediatric case.

Laparoscopic partial circular myectomy for congenital esophageal stenosis due to tracheobronchial remnant.

Congenital esophageal stenosis (CES) is a rare anomaly, and its appropriate management is not well established. This may be the first report describing laparoscopic partial circular myectomy of the esophageal wall in an infant with CES caused by tracheobronchial remnant (TBR). The narrow segment of the esophagus was laparoscopically detected 1 cm above the esophagogastric junction because the segment was whiter and narrower than the other parts of the esophagus. The narrow segment was approximately 1.5 cm in length. Partial anterior 270° circular muscle layers were dissected using hook electrocautery. Small cartilage-like tissues were identified during the procedure. The muscular layers of both ends were interruptedly sutured. Intraoperative complications were not detected. After undergoing balloon dilation for slight residual stenosis, the patient could eat solid foods without vomiting. Laparoscopic partial circular myectomy is safe and effective for short-segment lower esophageal stenosis in patients with CES caused by TBR.

Treatment guidelines for persistent cloaca, cloacal exstrophy, and Mayer-Rokitansky-Küster-Häuser syndrome for the appropriate transitional care of patients.

We developed treatment guidelines (TGs) for appropriate transitional care of the genitourinary system in patients with persistent cloaca (PC), cloacal exstrophy (CE), or Mayer-Rokitansky-Küster-Häuser syndrome (MRKH). These TGs are in accordance with the Medical Information Network Distribution Service (Minds), published in 2014 in Japan. Clinical questions (CQs) concerning treatment outcomes of the genitourinary system, pregnancy and delivery, and quality of life in adulthood were prepared as six themes for PC and CE and five themes for MRKH. We were able to publish statements on chronic renal dysfunction, hydrometrocolpos, and pregnancy, based on four CQs about PC, four about CE, and two about MRKH, respectively. However, due to the paucity of proper manuscripts, we were unable to make conclusions about the correct timing and method of vaginoplasty for patients with PC, CE, and MRKH or the usefulness of early bladder closure for patients with CE. These TGs may help clarify the current treatments for PC, CE, and MRKH in childhood, which have been carried out on an institutional basis. To improve clinical outcomes, systematic clinical trials revealing comprehensive clinical data of the urinary and reproductive systems, especially the length of the common channel in PC, are essential.

Multicenter, retrospective, comparative study of laparoscopic and open Kasai portoenterostomy in children with biliary atresia from Japanese high-volume centers.

BACKGROUND: Multicenter study was undertaken to analyze the results of laparoscopic and open Kasai portoenterostomy. METHODS: Subjects were infants with type III biliary atresia who underwent open operation (n = 106) or laparoscopic operation (n = 21) between January 2012 and December 2015. Clinical data were compared between open and laparoscopic operations (2016-0534). Propensity score matching was performed to reduce the effect of treatment selection bias. Multivariate analyses were used to estimate the effect of the surgical approach on the jaundice clearance rate and the native liver survival rate. RESULTS: The postoperative jaundice clearance rate and the 1-year native liver survival rate were not significantly different between open and laparoscopic operations. Rates of cholangitis and major complications of laparoscopic operation were comparable to those of open operation. Blood loss, time to resume oral intake, time to drain removal, and duration of analgesic usage of laparoscopic operation were significantly superior to those of open operation. Similar results were observed when analysis was adjusted based on propensity score. Multivariate analyses demonstrated that only age at operation was a poor prognostic factor. CONCLUSION: Laparoscopic Kasai portoenterostomy was associated with several favorable perioperative outcomes compared with open Kasai portoenterostomy. The difference of surgical approach was not a significant independent predictor.

Four new resin glycosides, murasakimasarins I-IV, from the tuber of Ipomoea batatas.

Four new resin glycosides having macrolactone structures (jalapins), murasakimasarins I-IV, were isolated from the tubers of Ipomoea batatas (L.) Lam. ('Murasakimasari', Convolvulaceae), along with three known glycosides. Their structures were determined on the basis of spectroscopic data as well as chemical evidence. Murasakimasarin III is the first representative of a resin glycoside with 10-methylundecanoic acid as the component organic acid.

Clinical practice guidelines for congenital hyperinsulinism.

Congenital hyperinsulinism is a rare condition, and following recent advances in diagnosis and treatment, it was considered necessary to formulate evidence-based clinical practice guidelines reflecting the most recent progress, to guide the practice of neonatologists, pediatric endocrinologists, general pediatricians, and pediatric surgeons. These guidelines cover a range of aspects, including general features of congenital hyperinsulinism, diagnostic criteria and tools for diagnosis, first- and second-line medical treatment, criteria for and details of surgical treatment, and future perspectives. These guidelines were generated as a collaborative effort between The Japanese Society for Pediatric Endocrinology and The Japanese Society of Pediatric Surgeons, and followed the official procedures of guideline generation to identify important clinical questions, perform a systematic literature review (April 2016), assess the evidence level of each paper, formulate the guidelines, and obtain public comments.

Continuous transanal decompression for infants with long- and total-type Hirschsprung's diseases as a bridge to curative surgery: a single-center experience.

BACKGROUND: The purpose of this study is to assess the usefulness of continuous bowel decompression using an indwelling transanal tube (ITT) for preoperative management in infants with long-segment (L)- or total (T)-type Hirschsprung's disease (HD). CASE PRESENTATION: Between 2012 and 2015, seven patients with L- or T-type HD underwent preoperative bowel management by continuous bowel decompression using an ITT during waiting period for curative surgery. Continuous bowel decompression was done using an ITT, a 10-12F flexible dual lumen tube placed through the rectum up to the dilated colon under fluoroscopic guidance and secured to the bilateral buttocks. The ITT tips were located at least in a dilated colon or the cecum if there was no radiographic transitional zone. The ITT was left open for continuous drainage, and its patency was checked by regular suction until the curative operation. The patient status and complications of this preoperative management were reviewed retrospectively. RESULTS: The median duration of decompression management was 65 (17-137) days. During decompression period, neither abdominal distention, enterocolitis, nor other complications occurred and six patients could stay at home until the curative operation. The weight-for-age Z-score at curative surgery was the same as or higher than that at birth in five patients. ITT replacement was needed three times per patient on an average for accidental ITT removal, ITT stenosis, or ITT hardening. CONCLUSIONS: Bowel management by continuous bowel decompression using an ITT is easy, safe, and effective for preoperative management in patients with L- or T-type HD and may permit single-stage surgery rendering colostomy or enterostomy unnecessary.

Generation of a bile salt export pump deficiency model using patient-specific induced pluripotent stem cell-derived hepatocyte-like cells.

Bile salt export pump (BSEP) plays an important role in hepatic secretion of bile acids and its deficiency results in severe cholestasis and liver failure. Mutation of the ABCB11 gene encoding BSEP induces BSEP deficiency and progressive familial intrahepatic cholestasis type 2 (PFIC2). Because liver transplantation remains standard treatment for PFIC2, the development of a novel therapeutic option is desired. However, a well reproducible model, which is essential for the new drug development for PFIC2, has not been established. Therefore, we attempted to establish a PFIC2 model by using iPSC technology. Human iPSCs were generated from patients with BSEP-deficiency (BD-iPSC), and were differentiated into hepatocyte-like cells (HLCs). In the BD-iPSC derived HLCs (BD-HLCs), BSEP was not expressed on the cell surface and the biliary excretion capacity was significantly impaired. We also identified a novel mutation in the 5'-untranslated region of the ABCB11 gene that led to aberrant RNA splicing in BD-HLCs. Furthermore, to evaluate the drug efficacy, BD-HLCs were treated with 4-phenylbutyrate (4PBA). The membrane BSEP expression level and the biliary excretion capacity in BD-HLCs were rescued by 4PBA treatment. In summary, we succeeded in establishing a PFIC2 model, which may be useful for its pathophysiological analysis and drug development.

Usefulness of a recanalized umbilical vein for vascular reconstruction in pediatric hepatic surgery.

PURPOSE: Pediatric surgeons currently engage in various abdominal vascular surgeries, which sometimes require vascular conduits or grafts. Herein, we report our experience with patients undergoing vascular reconstruction using a recanalized umbilical vein (rUV) and their long-term outcome. METHOD: Five patients with extrahepatic portal vein obstruction (EHPVO) underwent mesenterico-/porto-left portal vein (PV) bypass surgery using a short rUV conduit with an interposition vein graft. A sixth neonate with a huge hepatic tumor underwent PV reconstruction with anastomosis of rUV to the proximal PV stump following right hepatectomy with partial PV resection. A seventh patient underwent living donor liver transplantation for recurrent hepatoblastoma. The hepatic inferior vena cava (IVC) was resected because of tumor involvement and reconstructed by transposition of the infrahepatic IVC and interposition of rUV obtained from the donor liver graft. RESULTS: Sufficient flow through rUV was achieved and maintained in all patients without any complications during follow-up (0.7-6.9 years). Esophageal varices, splenomegaly, and other laboratory test abnormalities because of portal hypertension disappeared after surgery in patients with EHPVO. CONCLUSION: Our experience confirmed the usefulness and long-term patency of rUV as an entry to the intrahepatic PV and as a free vascular graft to reconstruct PV or IVC.