Ultrasonographically guided percutaneous transhepatic liver biopsy after pediatric liver transplantation.

BACKGROUND: Complications associated with ultrasonographically guided percutaneous transhepatic liver biopsy (PTLB) after liver transplantation (LT) have been rarely reported, and there is no consensus about its safety. We retrospectively reviewed the safety and outcomes of PTLB after pediatric LT. METHODS: Between January 2008 and December 2019, 8/1122 (0.71%) pediatric patients who underwent ultrasonographically guided PTLB after LT developed complications. The median age at PTLB was 7.8 years (range 0.1-17.9). Grafts included left lobe/left lateral segment in 1050 patients and others in 72. PTLB was performed using local anesthesia±sedation in 1028 patients and general anesthesia in 94. RESULTS: Complications after PTLB included acute cholangitis in 3 patients, sepsis in 2, respiratory failure due to over-sedation in 1, subcapsular hematoma in 1, and intrahepatic arterioportal fistula in 1. The incidence of complications of PTLB in patients with biopsy alone and those with simultaneous interventions was 0.49% and 3.19%, respectively (p = .023). Patients who developed acute cholangitis, respiratory failure, subcapsular hematoma, and arterioportal fistula improved with non-operative management. Of two patients with sepsis, one underwent PTLB and percutaneous transhepatic portal vein balloon dilatation and developed fever and seizures the following day. Sepsis was treated with antibiotic therapy. Another patient who underwent PTLB and exchange of percutaneous transhepatic biliary drainage catheter developed fever and impaired consciousness immediately. Sepsis was treated with antibiotic therapy, mechanical ventilation, and continuous hemofiltration. CONCLUSIONS: Percutaneous transhepatic liver biopsy after pediatric LT is safe. However, combining liver biopsy with simultaneous procedures for vascular and biliary complications is associated with an increased risk of complications.

The Causes and Outcomes of Early Relaparotomy Following Pediatric Living Donor Liver Transplantation.

Early relaparotomy of adult recipients after living donor liver transplantation (LDLT) is significantly associated with poor prognosis. However, there are few reports focusing on pediatric recipients after LDLT. The aim of this study is to clarify the causes and outcomes of early relaparotomy after pediatric LDLT. A total of 265 pediatric recipients (272 LDLTs) transplanted from May 2001 to October 2015 were retrospectively analyzed. Early relaparotomy was defined as surgical intervention performed within 3 months after LDLT. Early relaparotomy was performed 49 times for 33 recipients (12.5%). The recipient and graft survival rates in the early relaparotomy group were significantly lower than those in the nonearly relaparotomy group, respectively (75.0% and 63.6% versus 96.6% and 95.8%; both P < 0.001). Left lateral segment grafts were used significantly more frequently in the nonrelaparotomy group (P = 0.01). According to the multivariate analysis, the preoperative Pediatric End-Stage Liver Disease (PELD)/Model for End-Stage Liver Disease (MELD) score of the early relaparotomy group was significantly higher than that of the nonearly relaparotomy group (13.7 versus 6.3; P = 0.04). According to the receiver operating characteristic curve, the preoperative PELD/MELD score cutoff point was 17.2. Early relaparotomy due to infectious causes led to significantly poorer graft survival than that due to noninfectious causes (P = 0.04). In conclusion, the recipient and graft survival rates of the early relaparotomy group were significantly lower than those of the nonearly relaparotomy group. A high preoperative PELD/MELD score was a risk factor for early relaparotomy. In particular, early relaparotomy due to infection showed a poor prognosis.

Long-term outcome of percutaneous transhepatic biliary drainage for biliary strictures following pediatric liver transplantation.

BACKGROUND: We present a retrospective analysis of our experience with pediatric liver transplantation (LT), focusing on the long-term outcome of percutaneous transhepatic biliary drainage (PTBD) for post-transplant biliary strictures. METHODS: Fifty-three PTBDs were performed for 41 pediatric recipients with biliary strictures. The median ages at LT and PTBD were 1.4 and 4.4 years, respectively. The median observation period was 10.6 years. RESULTS: Post-transplant biliary strictures comprised anastomotic stricture (AS) in 28 cases, nonanastomotic stricture (NAS) in 12, anastomotic obstruction (AO) in 8, and nonanastomotic obstruction (NAO) in 5. The success rate of PTBD was 90.6%, and the 15-year primary patency rate of PTBD was 52.6%. The recurrence rate of biliary strictures after PTBD was 18.8% (9/48), and among the four NAS cases with recurrence, two underwent re-LT. The biliary obstruction rate was 27.1% (13/48). Among the eight cases with AO, five underwent the rendezvous method and three underwent surgical re-anastomosis. Among the five cases with NAO, one underwent re-LT. The recipient survival rate of PTBD treatment was 100%. CONCLUSIONS: The graft prognosis of AS by PTBD treatment is good and AO is curable by the rendezvous method and surgical re-anastomosis. However, the graft prognosis of NAS and NAO is poor.

Visceral artery anomalies in patients with Alagille syndrome.

BACKGROUND: Intracranial and pulmonary vascular anomalies are well-known complications and causes of mortality in AGS; however, visceral artery anomalies are less commonly recognized. Herein, we present a retrospective analysis of our experience with pediatric LDLT that focuses on the current problems with and treatments for visceral artery anomalies in AGS after LDLT. METHODS: Between May 2001 and December 2017, 294 LDLTs were performed for 285 pediatric recipients. Of these, 13 LDLTs (4.4%) for 12 AGS patients were performed. We classified the visceral artery anomalies into aneurysms and stenosis. RESULTS: The overall incidence of visceral aneurysm was 2 of 12 recipients (16.7%) and included a SMA aneurysm in one patient and an IPDA aneurysm with a subsequent SPA aneurysm in one patient; the ages of the diagnosis of visceral aneurysm were 16.3, 21.1, and 21.7 y, respectively. An endovascular treatment was performed for a progressive IPDA saccular aneurysm (12.0 × 14.5 × 15.0 mm). The overall incidence of visceral artery stenosis was 7 of 12 recipients (58.3%) and the median age at the diagnosis of visceral artery stenosis was 15.5 y (range 1.7-22.9 y). All 3 AGS patients with RA stenosis suffered from renal dysfunction (eGFR of 51, 78, and 51 mL/min/1.73m2 ). CONCLUSION: The morbidity of visceral artery anomalies is not negligible. The performance of periodic imaging examinations is necessary, even for infants, because it is difficult to detect visceral vascular anomalies in the infant stage.

Serum Mac-2 binding protein glycosylation isomer predicts the activation of hepatic stellate cells after liver transplantation.

BACKGROUND AND AIM: Serum Mac-2 binding protein glycosylation isomer (M2BPGi) is a novel fibrosis marker for various chronic liver diseases. We investigated the ability of M2BPGi to predict liver fibrosis in liver transplant (LT) recipients. METHODS: A total of 116 liver biopsies were performed in 113 LT recipients. The serum level of M2BPGi was also measured on the same day. The median age at LT and liver biopsy was 1.1 and 11.8 years, respectively. Serum M2BPGi levels and liver fibrosis status using METAVIR fibrosis score were compared. Immunohistological evaluation by anti-α-smooth-muscle actin (αSMA) was performed, and the relationship between αSMA positive rate and serum M2BPGi levels was investigated. RESULTS: The median M2BPGi level was 0.78 (range, 0.22-9.50), and 65, 29, 16, 5, and 1 patient(s) had METAVIR fibrosis scores of F0, F1, F2, F3, and F4, respectively. In patients with F0 fibrosis, median M2BPGi level was 0.69 and was significantly lower than in patients with F1 (median 0.99, P < 0.01), F2 (median 1.00, P = 0.01), and F3 fibrosis (median 1.53, P < 0.01). Area-under-the-curve analysis of the ability of M2BPGi level to predict liver fibrosis grade were > F1: 0.716, > F2: 0.720, and > F3: 0.900. Three patients with acute cellular rejection showed high levels of M2BPGi, which decreased after the treatment. A positive correlation existed between M2BPGi levels and αSMA positive rate (r2  = 0.715, P < 0.01). CONCLUSION: Mac-2 binding protein glycosylation isomer is a novel liver fibrosis marker in LT recipients and is also increased in patients with acute liver injuries, especially acute cellular rejection, even when fibrosis is absent.

Endovascular stent placement for venous complications following pediatric liver transplantation: outcomes and indications.

PURPOSE: Advances in interventional radiology (IVR) treatment have notably improved the prognosis of hepatic vein (HV) and portal vein (PV) complications following pediatric living donor liver transplantation (LDLT); however, graft failure may develop in refractory cases. Although endovascular stent placement is considered for recurrent stenosis, its indications are controversial. METHODS: We enrolled 282 patients who underwent pediatric LDLT in our department from May 2001 to September 2016. RESULTS: 22 (7.8%) HV complications occurred after LDLT. Recurrence was observed in 45.5% of the patients after the initial treatment, and 2 patients (9.1%) underwent endovascular stent placement. The stents were inserted at 8 months and 3.8 years following LDLT, respectively. After stent placement, both patients developed thrombotic obstruction and are currently being considered for re-transplantation. 40 (14.2%) PV complications occurred after LDLT. Recurrence occurred in 27.5% of the patients after the initial treatment, and 4 patients (10.0%) underwent endovascular stent treatment. The stents of all the patients remained patent, with an average patency duration of 41 months. CONCLUSION: Endovascular stent placement is an effective treatment for intractable PV complications following pediatric LDLT. However, endovascular stent placement for HV complications should be carefully performed because of the risk of intrastent thrombotic occlusion and the possibility of immunological venous injury.

Interventional radiology treatment for vascular and biliary complications following pediatric living donor liver transplantation - a retrospective study.

There are few long-term outcome reports for interventional radiology (IVR) treatments for vascular and biliary complications following pediatric living donor liver transplantation (LDLT). Herein, we presented our institution's experience and investigated the efficacy and issues of long-term outcome with IVR treatments. Between May 2001 and September 2016, 279 pediatric LDLTs were performed. The median age at LDLT was 1.4 years old, and the median observation period was 8.2 years. All the biliary reconstructions at LDLT were hepaticojejunostomy. The IVR treatments were selected as endovascular, radiological, or endoscopic interventions. Post-transplant hepatic vein, portal vein, hepatic artery, and biliary complications were present in 7.9%, 14.0%, 5.4%, and 18.3%, respectively. IVR treatment was the first treatment option in 81.8%, 94.9%, 46.7%, and 94.1%, respectively. The recurrence and cure rates following IVR treatment were 42.1%, 21.1%, 44.4%, and 34.0% and 84.2%, 97.4%, 100%, and 88.0%, respectively. The graft survival rates in patients with and without post-transplant vascular and biliary complications were 94.4% and 90.6%, respectively (P = 0.522). The IVR treatments for vascular and biliary complications following pediatric LDLT are the first choice option. Although the recurrence following IVR treatment is a major problem and it is necessary to carefully perform long-term follow-up, IVR treatments have good treatment outcomes.

Dorsal approach plus branch patch technique is the preferred method for liver transplanting small babies with monosegmental grafts.

PURPOSE: When living donor liver transplantation (LDLT) is performed on small infant patients, the incidence of hepatic artery complications (HACs) is high. Here, we present a retrospective analysis that focuses on our surgical procedure for hepatic arterial reconstruction and the outcomes of monosegmental LDLT. METHODS: Of the 275 patients who underwent LDLT between May 2001 and December 2015, 13 patients (4.7 %) underwent monosegmental LDLT. Hepatic artery reconstruction was performed under a microscope. The size discrepancy between the graft and the recipient's abdominal cavity was defined as the graft to recipient distance ratio (GRDR) between the left hepatic vein and the portal vein (PV) bifurcation on a preoperative computed tomography scan. HACs were defined as hepatic arterial hypoperfusion. RESULTS: Recipient hepatic arteries were selected for the branch patch technique in five cases (38.5 %), and the diameter was 2.2 ± 0.6 mm. The anastomotic approaches selected were the dorsal position of the PV in seven cases (53.8 %) and the ventral position in six, and the GRDRs were 2.8 ± 0.4 and 1.9 ± 0.5, respectively (p = 0.012). The incidence rate of HACs caused by external factors, such as compression or inflammation around the anastomotic site, was significantly higher in monosegmental than in non-monosegmental graft recipients (15.4 vs. 1.1 %, p < 0.001). CONCLUSION: Although monosegmental graft recipients experienced HACs caused by external factors around the anastomotic field, hepatic arterial reconstruction could be safely performed. Important components of successful hepatic arterial reconstructions include the employment of the branch patch technique and the selection of the dorsal approach.

Recanalized umbilico-caval anastomosis as a temporary portosystemic shunt in pediatric living donor liver transplantation: the crossed fingers method.

A temporary portocaval shunt (TPCS) associated with retrohepatic vena cava preservation prevents the edema caused by splanchnic congestion during liver transplantation (LT), especially for non-cirrhotic cases. We herein report a modified TPCS technique using the recanalized umbilical vein and an end-to-side recanalized umbilico-caval anastomosis for use during pediatric living donor liver transplantation (LDLT). This work evaluated a group of pediatric patients who underwent LDLT between 2001 and 2014 with the conventional TPCS (n=16) vs the recanalized umbilico-caval shunt (the crossed fingers method, n=10). The crossed fingers method was performed by suturing an end-to-side anastomosis of the patent or recanalized umbilical vein to the vena cava using a continuous monofilament suture like "crossing the fingers," that is, placing the left portal vein across the portal vein trunk next to it. The preoperative, surgical, and postoperative characteristics were similar in both groups except for the significantly shorter portal vein clamping time for the crossed fingers method. This method can allow the portal circulation to be totally decompressed before and after implanting the graft and while maintaining the hemodynamic stability throughout all stages of pediatric LDLT.

Antenatal immunoglobulin for prevention of neonatal hemochromatosis.

Neonatal hemochromatosis (NH) is a rare disease with a poor prognosis, particularly prior to 2008. Antenatal maternal high-dose immunoglobulin (Ig) is effective in preventing NH recurrence, but the adverse effects of this treatment have not been documented as yet. Here, we report on a patient who underwent high-dose Ig treatment to prevent NH recurrence. The patient was a 31-year-old pregnant Japanese woman. Her first child died of NH after receiving living donor liver transplantation. The patient received high-dose Ig treatment to prevent recurrence of NH from gestational weeks 16 to 35. During the treatment, platelet count gradually decreased, and cesarean section was required at 35 gestational weeks. The child did not develop liver failure. High-dose Ig prevented the recurrence of NH. Caution should be exercised due to possible adverse effects of this treatment.

A Gelatin Hydrogel Nonwoven Fabric Combined With Adipose Tissue-Derived Stem Cells Enhances Subcutaneous Islet Engraftment.

Subcutaneous islet transplantation is a promising treatment for severe diabetes; however, poor engraftment hinders its prevalence. We previously revealed that a gelatin hydrogel nonwoven fabric (GHNF) markedly improved subcutaneous islet engraftment. We herein investigated whether the addition of adipose tissue-derived stem cells (ADSCs) to GHNF affected the outcome. A silicone spacer sandwiched between two GHNFs with (AG group) or without (GHNF group) ADSCs, or a silicone spacer alone (Silicone group) was implanted into the subcutaneous space of healthy mice at 6 weeks before transplantation, then diabetes was induced 7 days before transplantation. Syngeneic islets were transplanted into the pretreated space. Intraportal transplantation (IPO group) was also performed to compare the transplant efficiency. Blood glucose, intraperitoneal glucose tolerance, immunohistochemistry, and inflammatory mediators were evaluated. The results in the subcutaneous transplantation were compared using the Silicone group as a control. The results of the IPO group were also compared with those of the AG group. The AG group showed significantly better blood glucose changes than the Silicone and the IPO groups. The cure rate of AG group (72.7%) was the highest among the groups (GHNF; 40.0%, IPO; 40.0%, Silicone; 0%). The number of vWF-positive vessels in the subcutaneous space of the AG group was significantly higher than that in other groups before transplantation (P < 0.01). Lectin angiography also showed that the same results (P < 0.05). According to the results of the ADSCs tracing, ADSCs did not exist at the transplant site (6 weeks after implantation). The positive rates for laminin and collagen III constructed around the transplanted islets did not differ among groups. Inflammatory mediators were higher in the Silicone group, followed by the AG and GHNF groups. Pretreatment using bioabsorbable scaffolds combined with ADSCs enhanced neovascularization in subcutaneous space, and subcutaneous islet transplantation using GHNF with ADSCs was superior to intraportal islet transplantation.

Ideal Duration of Pretreatment Using a Gelatin Hydrogel Nonwoven Fabric Prior to Subcutaneous Islet Transplantation.

Subcutaneous islet transplantation is a promising treatment for severe diabetes; however, poor engraftment hinders its prevalence. We previously revealed that a gelatin hydrogel nonwoven fabric (GHNF) markedly improved subcutaneous islet engraftment in comparison with intraportal islet transplantation. We herein investigated whether the duration of pretreatment using GHNF affected the outcome of subcutaneous islet transplantation. A silicone spacer with GHNF was implanted into the subcutaneous space of healthy mice at 2, 4, 6, or 8 weeks before transplantation, and then diabetes was induced 7 days before transplantation. Syngeneic islets were transplanted into the pretreated space. Blood glucose, intraperitoneal glucose tolerance, immunohistochemistry, inflammatory mediators, and gene expression were evaluated. The 6-week group showed significantly better blood glucose changes than the other groups (P < 0.05). The cure rate of the 6-week group (60.0%) was the highest among the groups (2-week = 0%, 4-week = 50.0%, 8-week = 15.4%). The number of von Willebrand factor (vWF)-positive vessels in the 6-week group was significantly higher than in the other groups at pre-islet and post-islet transplantation (P < 0.01 [vs 2-and 4-week groups] and P < 0.05 [vs all other groups], respectively). Notably, this beneficial effect was also observed when GHNF was implanted into diabetic mice injected with streptozotocin 7 days before GHNF implantation. The positive rates for laminin, collagen III, and collagen IV increased as the duration of pretreatment became longer and were significantly higher in the 8-week group (P < 0.01). Inflammatory mediators, including interleukin (IL)-1b, granulocyte colony-stimulating factor (G-CSF), and interferon (IFN)-γ, were gradually downregulated according to the duration of GHNF pretreatment and re-elevated in the 8-week group. Taken together, the duration of GHNF pretreatment apparently had an impact on the outcomes of subcutaneous islet transplantation, and 6 weeks appeared to be the ideal duration. Islet graft revascularization, extracellular matrix compensation of the islet capsule, and the inflammatory status at the subcutaneous space would be crucial factors for successful subcutaneous islet transplantation.

A Gelatin Hydrogel Nonwoven Fabric Enhances Subcutaneous Islet Engraftment in Rats.

Although subcutaneous islet transplantation has many advantages, the subcutaneous space is poor in vessels and transplant efficiency is still low in animal models, except in mice. Subcutaneous islet transplantation using a two-step approach has been proposed, in which a favorable cavity is first prepared using various materials, followed by islet transplantation into the preformed cavity. We previously reported the efficacy of pretreatment using gelatin hydrogel nonwoven fabric (GHNF), and the length of the pretreatment period influenced the results in a mouse model. We investigated whether the preimplantation of GHNF could improve the subcutaneous islet transplantation outcomes in a rat model. GHNF sheets sandwiching a silicone spacer (GHNF group) and silicone spacers without GHNF sheets (control group) were implanted into the subcutaneous space of recipients three weeks before islet transplantation, and diabetes was induced seven days before islet transplantation. Syngeneic islets were transplanted into the space where the silicone spacer was removed. Blood glucose levels, glucose tolerance, immunohistochemistry, and neovascularization were evaluated. The GHNF group showed significantly better blood glucose changes than the control group (p < 0.01). The cure rate was significantly higher in the GHNF group (p < 0.05). The number of vWF-positive vessels was significantly higher in the GHNF group (p < 0.01), and lectin angiography showed the same tendency (p < 0.05). The expression of laminin and collagen III around the transplanted islets was also higher in the GHNF group (p < 0.01). GHNF pretreatment was effective in a rat model, and the main mechanisms might be neovascularization and compensation of the extracellular matrices.

Cotransplantation With Adipose Tissue-derived Stem Cells Improves Engraftment of Transplanted Hepatocytes.

BACKGROUND: Hepatocyte transplantation is expected to be an alternative therapy to liver transplantation; however, poor engraftment is a severe obstacle to be overcome. The adipose tissue-derived stem cells (ADSCs) are known to improve engraftment of transplanted pancreatic islets, which have many similarities to the hepatocytes. Therefore, we examined the effects and underlying mechanisms of ADSC cotransplantation on hepatocyte engraftment. METHODS: Hepatocytes and ADSCs were cotransplanted into the renal subcapsular space and livers of syngeneic analbuminemic rats, and the serum albumin level was quantified to evaluate engraftment. Immunohistochemical staining and fluorescent staining to trace transplanted cells in the liver were also performed. To investigate the mechanisms, cocultured supernatants were analyzed by a multiplex assay and inhibition test using neutralizing antibodies for target factors. RESULTS: Hepatocyte engraftment at both transplant sites was significantly improved by ADSC cotransplantation ( P < 0.001, P < 0.001). In the renal subcapsular model, close proximity between hepatocytes and ADSCs was necessary to exert this effect. Unexpectedly, ≈50% of transplanted hepatocytes were attached by ADSCs in the liver. In an in vitro study, the hepatocyte function was significantly improved by ADSC coculture supernatant ( P < 0.001). The multiplex assay and inhibition test demonstrated that hepatocyte growth factor, vascular endothelial growth factor, and interleukin-6 may be key factors for the abovementioned effects of ADSCs. CONCLUSIONS: The present study revealed that ADSC cotransplantation can improve the engraftment of transplanted hepatocytes. This effect may be based on crucial factors, such as hepatocyte growth factor, vascular endothelial growth factor, and interleukin-6, which are secreted by ADSCs.

Development of a novel method for measuring tissue oxygen pressure to improve the hypoxic condition in subcutaneous islet transplantation.

Subcutaneous tissue is a promising site for islet transplantation, but poor engraftment, due to hypoxia and low vascularity, hinders its prevalence. However, oxygen partial pressure (pO2) of the subcutaneous space (SC) and other sites were reported to be equivalent in several previous reports. This contradiction may be based on accidental puncture to the indwelling micro-vessels in target tissues. We therefore developed a novel optical sensor system, instead of a conventional Clark-type needle probe, for measuring tissue pO2 and found that pO2 of the SC was extremely low in comparison to other sites. To verify the utility of this method, we transplanted syngeneic rat islets subcutaneously into diabetic recipients under several oxygenation conditions using an oxygen delivery device, then performed pO2 measurement, glucose tolerance, and immunohistochemistry. The optical sensor system was validated by correlating the pO2 values with the transplanted islet function. Interestingly, this novel technique revealed that islet viability estimated by ATP/DNA assay reduced to less than 75% by hypoxic condition at the SC, indicating that islet engraftment may substantially improve if the pO2 levels reach those of the renal subcapsular space. Further refinements for a hypoxic condition using the present technique may contribute to improving the efficiency of subcutaneous islet transplantation.

Outcomes After Living Donor Liver Transplantation in Pediatric Patients with Inherited Metabolic Diseases.

BACKGROUND There is no consensus about the long-term prognosis of pediatric patients with a variety of rare liver diseases but with inherited metabolic diseases (IMDs). We retrospectively reviewed the developmental outcomes of patients with IMDs undergoing living donor liver transplantation (LDLT). MATERIAL AND METHODS Between May 2001 and December 2020, of 314 pediatric patients who underwent LDLT, 44 (14%) had IMDs. The median age at LDLT was 3.0 years old (range 0-15.0 years). Associations between the post-transplant complications and graft survival rate in patients with IMDs and biliary atresia (BA) were calculated. We evaluated the safety of LDLT from heterozygous carrier donors, the prognosis of patients with IMDs who have metabolic defects expressed in other organs, and developmental outcomes of patients with IMDs. RESULTS The 10-year graft survival rates in patients with IMDs and BA were 87% and 94%, respectively (P=0.041), and the causes of graft failure included pneumocystis pneumonia, acute lung failure, hemophagocytic syndrome, hepatic vein thrombosis, portal vein thrombosis, and sepsis. The rate of post-transplant cytomegalovirus viremia in patients with IMDs was higher than that of patients with BA (P=0.039). Of 39 patients with IMDs, 15 patients (38%) had severe motor and intellectual disabilities in 4 patients, intellectual developmental disorders including epilepsy in 2, and attention-deficit hyperactivity disorder in 2. Of 28 patients with IMDs, 13 (46%) needed special education. CONCLUSIONS The long-term outcomes of LDLT in patients with IMDs are good. However, further long-term social and educational follow-up regarding intellectual developmental disorders is needed.

Liver Transplant for Posthepatectomy Liver Failure in Hepatoblastoma.

OBJECTIVES: Predicting the risk of posthepatectomy liver failure is important when performing extended hepatectomy. However, there is no established method to evaluate liver function and improve preoperative liver function in pediatric patients. MATERIALS AND METHODS: We show the clinical features of pediatric patients who underwent living donor liver transplant for posthepatectomy liver failure in hepatoblastoma. The subjects were 4 patients with hepatoblastoma who were classified as Pretreatment Extent of Disease III, 2 of whom had distal metastasis (chest wall and lung). RESULTS: Hepatic right trisegmentectomy was performed in 3 patients and extended left hepatectomy in 1 patient. The median alpha-fetoprotein level at the diagnosis of hepatoblastoma was 986300 ng/mL (range, 22500-2726350 ng/mL), and the median alpha-fetoprotein level before hepatectomy was 8489 ng/mL (range, 23-22500 ng/mL). The remnant liver volume after hepatectomy was 33.3% (range, 20% to 34.9%). Four patients had cholangitis after hepatectomy and progressed to posthepatectomy liver failure. The peak serum total bilirubin after hepatectomy was 11.4 mg/dL (range, 8.7-14.6 mg/dL). Living donor liver transplant was performed for these 4 patients with posthepatectomy liver failure, and they did not have a recurrence. CONCLUSIONS: When the predictive remnant liver volume by computed tomography-volumetry before extended hepatectomy for patients with hepatoblastoma is less than 40%, the possibility of posthepatectomy liver failure should be recognized.