Criteria for immediate extubation after pediatric liver transplantation in a single pediatric liver transplant center in Japan.

Immediate extubation (IE) following liver transplantation (LT) has become the standard practice, even for pediatric patients. However, no preoperative or postoperative case selection protocols for IE are currently available. We have developed selection criteria for IE following pediatric LT. The aim of this study is to assess the safety and effectiveness of these selection criteria and anesthetic management protocol implemented in our hospital for IE after pediatric LT. METHOD: This was a retrospective study. The records of all cases undergoing LT in our center from January 2016 to December 2020 were collected. We excluded cases > 18 years old at the time of LT. Enrolled cases were divided into two groups: cases with immediate extubation (IE) or without immediate extubation (NIE). We compared preoperative conditions, intraoperative management, and postoperative courses. Finally, we classified NIE group patients into cases extubated at postoperative day 1 (early; E-NIE) and others (delayed; D-NIE) and compared their underlying diseases and postoperative courses. RESULTS: In the IE group, there were 81 cases, while the NIE group consisted of 185 cases. All patients in the IE group were successfully extubated without any instances of re-intubation due to respiratory failure. Within the E-NIE group, comprising 130 cases, all patients were ultimately extubated without the need for tracheostomy. However, in the D-NIE group, which encompassed 53 cases, seven patients required tracheostomy. CONCLUSION: In our center, the implementation of our anesthesia management protocol and the use of pre/postoperative case selection criteria have allowed for the safe practice of IE following pediatric LT. However, it should be noted that patients who cannot be extubated by Postoperative Day 1 (POD1) may be at an increased risk of requiring a tracheostomy. When contemplating IE, it is crucial to take into account the disease-specific physiological aspects and surgical site situations.

Impact of preoperative bloodstream infection on outcomes of pediatric liver transplant recipients treated for acute liver failure.

BACKGROUND: Acute liver failure (ALF) is a component of multisystem organ failure that causes severe liver dysfunction in patients without underlying chronic liver disease. The patients with ALF are prone to have infections, including bacteremia. However, studies of the infectious impact for post liver transplantation (LT) in pediatric ALF are limited. We aimed to evaluate our current practice for pediatric LT cases of ALF with preoperative bacteremia. METHODS: The records of all patients under 18 years old undergoing LT for ALF in our center from November 2005 to December 2021 were collected. They were divided into two groups: those with a preoperative bloodstream infection (BSI) and those without (NBSI). We compared the preoperative status and also reviewed the details of the BSI group. Intraoperative course and postoperative outcomes were also compared. RESULTS: There were 19 BSI patients and 66 NBSI patients. One BSI case was detected on the day of LT. This patient had no changes in vital signs and general condition. After evaluation and therapeutic intervention by pediatric infectious disease specialists, LT was performed on the same day. Five cases developed septic shock at the time of detection of BSI. All BSI patients were in stable condition on the operation day with proper interventions. There were no significant differences in mortality and hospital stay between both groups. CONCLUSIONS: LT might be able to be performed for pediatric ALF even with positive blood cultures. In addition, appropriate therapeutic intervention by specialists and patient's stable condition before LT are essential.

The role of liver transplantation in COACH syndrome (Joubert syndrome with congenital hepatic fibrosis): A review of the literature.

BACKGROUND: COACH syndrome is a rare autosomal recessive genetic disease characterized by liver fibrosis, which leads to severe complications related to portal hypertension. However, only a few patients with COACH syndrome undergoing liver transplantation (LT) have been reported. MATERIALS AND METHODS: We herein report the outcomes of four children who underwent LT for COACH syndrome at our institute and review three previously reported cases to elucidate the role of LT in COACH syndrome. RESULTS: All four patients in our institute were female, and three received living donors LT. All patients were diagnosed with COACH syndrome by genetic testing. LT was performed in these patients at 3, 7, 9, and 14 years old. The indication for LT was varices related to portal hypertension in all patients. One showed an intrapulmonary shunt. Blood tests revealed renal impairment due to nephronophthisis in three patients, and one developed renal insufficiency after LT. The liver function was maintained in all patients. A literature review revealed detailed information for three more patients. The indication for LT in these three cases was portal hypertension, such as bleeding from esophageal varices. One patient had chronic renal failure on hemodialysis at LT and underwent combined liver and kidney transplantation. Of these three previous patients, one died from hepatic failure due to de novo HCV infection 3 years after LT. CONCLUSIONS: LT should be considered an effective treatment for COACH syndrome in patients with severe portal hypertension. However, a detailed follow-up of the renal function is necessary.

Living-donor liver transplantation for methylmalonic acidemia patient with hepatocellular carcinoma: A case report and literature review.

BACKGROUND: Methylmalonic acidemia (MMA) is an autosomal recessive disorder caused by defects in propionyl-CoA (P-CoA) catabolism; of note, liver neoplasms rarely occur as a long-term complication of the disorder. Herein, we report the case of a patient with MMA and hepatocellular carcinoma (HCC) who was successfully treated with a living-donor liver transplant (LDLT) following prior kidney transplantation. CASE REPORT: A 25-year-old male patient with MMA underwent LDLT with a left lobe graft because of metabolic instability and liver neoplasms. He had presented with chronic symptoms of MMA, which had been diagnosed by genetic testing. Additionally, he had undergone living-donor kidney transplantation with his father as the donor due to end-stage kidney disease 6 years before the LDLT. He had an episode of metabolic decompensation triggered by coronavirus disease in 2019. Imaging studies revealed an intrahepatic neoplasm in the right hepatic lobe. Due to concerns about metabolic decompensation after hepatectomy, LDLT was performed using a left lobe graft obtained from the patient's mother. Pathological findings were consistent with the characteristics of well-to-moderately differentiated HCC. The postoperative course was uneventful, and the patient was discharged 48 days after the LDLT without any complications. At the 9-month follow-up, the patient's condition was satisfactory, with sufficient liver graft function and without metabolic decompensation. CONCLUSION: This case indicates that although HCC is a rare complication in patients with MMA, clinicians should be aware of hepatic malignancies during long-term follow-up.

Significance of a multidisciplinary approach to congenital extrahepatic portosystemic shunt: A changing paradigm for the treatment.

AIM: To review the current institutional practice to treat patients with congenital extrahepatic portosystemic shunt (CEPS) and to determine the optimal strategy. METHODS: We retrospectively reviewed the records of 55 patients diagnosed with CEPS at our center between December 2008 and March 2022. RESULTS: Among these 55 patients, 44 (80.0%) received treatment for CEPS at a median age of 4.7 years. The most common indication for treatment was cardiopulmonary complications (45.5%). Therapeutic intervention included shunt closure by endovascular techniques (50.0%) or surgery (40.9%), and liver transplantation (9.1%). A total of 11 were classified as short shunt types, and surgical ligation was performed in all to preserve the major vascular system and prevent complications (p < 0.001). Children who received a surgical ligation were more likely to develop complications after shunt closure (p = 0.02). Among seven patients with portopulmonary hypertension (POPH), one patient, who received a shunt ligation at <1 year-of-age, was only able to completely discontinue medication. Most other CEPS-related complications were completely resolved. Post-treatment complications, including thrombosis and symptoms of portal hypertension, were seen in 16 patients. After shunt closure, one patient was scheduled to undergo liver transplantation for progressive POPH and large residual hepatocellular adenoma. During follow-up, one patient without any treatment for CEPS developed POPH 16 years from the diagnosis. CONCLUSION: Earlier therapeutic interventions should be strongly considered for patients with POPH related to CEPS. However, in view of the invasiveness and treatment complications, special attention should be paid to the management of patients with short shunt types.

Rare sequence variants associated with the risk of non-syndromic biliary atresia.

AIM: The etiology of non-syndromic biliary atresia (BA) remains largely unknown. In this study, we performed genome-wide screening of genes associated with the risk of non-syndromic BA. METHODS: We analyzed exome data of 15 Japanese patients with non-syndromic BA and 509 control individuals using an optimal sequence kernel association test (SKAT-O), a gene-based association study optimized for small-number subjects. Furthermore, we examined the frequencies of known BA-related single-nucleotide polymorphisms in the BA and control groups. RESULTS: SKAT-O showed that rare damaging variants of MFHAS1, a ubiquitously expressed gene encoding a Toll-like receptor-associated protein, were more common in the BA group than in the control group (Bonferroni corrected p-value = 0.0097). Specifically, p.Val106Gly and p.Arg556Cys significantly accumulated in the patient group. These variants resided within functionally important domains. SKAT-O excluded the presence of other genes significantly associated with the disease risk. Of 60 known BA-associated single-nucleotide polymorphisms, only eight were identified in the BA group. In particular, p.Ile3421Met of MYO15A and p.Ala421Thr of THOC2 were more common in the BA group than in the control group. However, the significance of these two variants is questionable, because MYO15A has been linked to deafness, but not to BA, and the p.Ala421Thr of THOC2 represents a relatively common single-nucleotide polymorphism in Asia. CONCLUSIONS: The results of this study indicate that rare damaging variants in MFHAS1 may constitute a risk factor for non-syndromic BA, whereas the contribution of other monogenic variants to the disease predisposition is limited.

Successful pediatric liver transplantation case with a positive SARS-CoV-2 test at the time of transplant.

AIM: We report a successful liver transplantation (LT) in a child with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. CASE PRESENTATION: A 3-year-old female patient with decompensated cirrhosis due to Alagille syndrome underwent a split LT with a left lateral segment graft. She had a history of SARS-CoV-2 infection 4 months before LT. She was exposed to SARS-CoV-2 after the decision for organ acceptance. We repeatedly confirmed the negative SARS-CoV-2 test by polymerase chain reaction (PCR) before LT. Liver transplantation was carried out in the negative pressure operational theater with full airborne, droplet, and contact precautions as the patient was considered to be within the incubation period of SARS-CoV-2. The SARS-CoV-2 PCR test became positive in the nasopharyngeal swab specimen at the operation. Remdesivir, the antiviral treatment, was held off due to potential hepatotoxicity and no exacerbation of COVID-19. She received tacrolimus and low-dose steroids per protocol. She remained SARS-CoV-2 positive on postoperative days (PODs) 1, 2, and 5. The presence of antibodies for SARS-CoV-2 at LT was confirmed later. On POD 53, she was discharged without any symptomatic infection. CONCLUSION: This case demonstrated that a positive SARS-CoV-2 result was not an absolute contraindication for a life-saving LT. Liver transplantation could be safely performed in a pediatric patient with asymptomatic COVID-19 and S-immunoglobulin G antibodies for SARS-CoV-2.

Optimal graft size in pediatric living donor liver transplantation: How are children different from adults?

BACKGROUND: Pediatric liver transplantation is an established treatment for end-stage liver disease in children. However, it is still posing relevant challenges, such as optimizing the graft selection according to the recipient size. Unlike adults, small children tolerate large-for-size grafts and insufficient graft volume might represent an issue in adolescents when graft size is disproportionate. METHODS: Graft-size matching strategies over time were examined in pediatric liver transplantation. This review traces the measures/principles put in place to prevent large-for-size or small-for-size grafts in small children to adolescents with a literature review and an analysis of the data issued from the National Center for Child Health and Development, Tokyo, Japan. RESULTS: Reduced left lateral segment (LLS; Couinaud's segment II and III) was widely applicable for small children less than 5 kg with metabolic liver disease or acute liver failure. There was significantly worse graft survival if the actual graft-to-recipient weight ratio (GRWR) was less than 1.5% in the adolescent with LLS graft due to the small-for-size graft. Children, particularly adolescents, may then require larger GRWR than adults to prevent small-for-size syndrome. The suggested ideal graft selections in pediatric LDLT are: reduced LLS, recipient body weight (BW) < 5.0 kg; LLS, 5.0 kg ≤ BW < 25 kg; left lobe (Couinaud's segment II, III, IV with middle hepatic vein), 25 kg ≤ BW < 50 kg; right lobe (Couinaud's segment V, VI, VII, VIII without middle hepatic vein), 50 kg ≤ BW. Children, particularly adolescents, may then require larger GRWR than adults to prevent small-for-size syndrome. CONCLUSION: Age-appropriate and BW-appropriate strategies of graft selection are crucial to secure an excellent outcome in pediatric living donor liver transplantation.

Portal vein pressure and flow modulation in pediatric liver transplantation.

Liver transplantation (LT) has been indicated for smaller and more clinically severe patients in recent years. Small biliary atresia (BA) patients often show portal hypoplasia and sclerotic portal vein (PV), which may make PV reconstruction more difficult during the operation. Among PV complications, intraoperative PV thrombosis can be considered a disaster, and it is important to prevent this catastrophic event by the precise assessment of the PV structure and PVF using radiological imaging before and during LT. However, there are no objective parameters to indicate whether sufficient PVF can be obtained. PV pressure (PVP) and PV flow (PVF) have mainly been studied in adult living donor LT, for the purpose of preventing small-for-size syndrome, and PVP has been considered an objective parameter of graft inflow modulation (GIM). In the setting of pediatric LT, GIM is mainly performed to prevent hypoperfusion, and it must be performed before graft implantation. GIM to maximize the PVF of pediatric patients with potentially low PVF in LT consists of the interruption of collateral vessels, the assessment of the usability of the native PV, and technical modifications in PV reconstruction. Reliable objective parameters that represent sufficient PVF before graft implantation are desired. Our recent study proposed that a PVP of ≥25 mmHg before graft implantation can be considered an objective parameter to obtain sufficient PVF (cutoff value: 50 mL/min/100 g of graft weight). Further investigation is needed to determine the best strategy for successful PV reconstruction in pediatric LT.

Associating liver partition and portal vein ligation for staged hepatectomy as bridging therapy for liver transplantation in an infant with an advanced hepatic rhabdoid tumor.

BACKGROUND: Malignant rhabdoid tumors (MRTs) are rare, aggressive tumors that mainly affect children and currently lack effective chemotherapeutic regimens. Liver MRTs are particularly challenging to manage due to the difficulty of performing one-stage liver resection, and preemptive liver transplantation is associated with high recurrence rates. However, the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) technique offers a promising surgical approach for advanced-stage liver tumors where conventional liver resection is not feasible. CASE REPORT: A patient with a large liver rhabdoid tumor that had invaded the three main hepatic veins underwent four courses of cisplatin-pirarubicin chemotherapy. ALPPS was performed due to insufficient residual liver capacity, with hepatic parenchymal dissection between the anterior and posterior liver zones in the first stage of surgery. After confirming adequate remaining liver volume, the liver was resected except for S1 and S6 on postoperative day 14. LDLT was performed 7 months after ALPPS due to the gradual deterioration of liver function caused by chemotherapy. The patient was recurrence-free 22 and 15 months after ALPPS and LDLT, respectively. CONCLUSIONS: The ALPPS technique is a curative option for advanced-stage liver tumors that cannot be managed with conventional liver resection. In this case, ALPPS was used successfully to manage a large liver rhabdoid tumor. Then, liver transplantation was performed after chemotherapy. The ALPPS technique should be considered a potential treatment strategy for patients with advanced-stage liver tumors, particularly those who can undergo liver transplantation.

Perioperative risk factors for neurological impairment in infants with acute liver failure following liver transplantation.

BACKGROUND: Neurological impairment is not rare in infants with acute liver failure (ALF). This study aimed to investigate the perioperative risk factors for neurological impairment following liver transplantation (LT) in infantile ALF. METHODS: Retrospective analysis was performed in infants who were younger than 1 year with ALF who subsequently underwent LT at our hospital between January 2005 and December 2016. Patients were considered to have neurological impairment if the Pediatric Cerebral Performance Category score was between 2 and 5 at the age of 6 years. A comparison between the groups of infants with and without neurological impairment was performed, and factors with p < .10 in the comparison were analyzed using univariate logistic regression analysis for neurological impairment. RESULTS: Twenty-six infants survived until 6 years of age, and 31% (8/26) of them had neurological impairment. Patients with neurological impairment were significantly younger in age at ALF onset, had significantly higher pre-LT bilirubin and prothrombin time/international normalized ratio, and stayed significantly longer in the intensive care unit than those without neurological impairment. Total bilirubin (odds ratio (OR) = 1.12, 95% confidence interval (CI) 1.02-1.22, p = .012), indirect bilirubin (OR = 1.10, 95% CI 1.01-1.20, p = .025), direct bilirubin (OR = 1.22, 95% CI 1.01-1.47, p = .040), and age in month at ALF (OR = 0.76, 95% CI 0.58-0.999, p = .049) showed significant association with neurological impairment. CONCLUSIONS: High pre-LT peak bilirubin value and younger age at ALF onset can be perioperative risk factors for neurological impairment after LT in infantile ALF.

Optimal liver transplant procedure in progressive familial intrahepatic cholestasis type 1 treated with biliary diversion or intestinal transplantation: Lessons learned from three cases treated with different approaches.

BACKGROUND: Progressive familial intrahepatic cholestasis type 1 (PFIC1) is an autosomal recessive cholestatic liver disorder caused by ATP8B1 gene mutations. Although liver transplantation (LT) is indicated for progressive liver disease, postoperative complications, including severe diarrhea and graft steatohepatitis leading to graft loss, have been reported. CASES: The first patient had jaundice, pruritus, diarrhea, and growth retardation (weight z-score: -2.5; height z-score: -3.7). She underwent LT with total internal biliary diversion (TIBD) to the colon at 2 years of age. Graft biopsy at the 7-year follow-up examination revealed microvesicular steatosis (60%). Her diarrhea improved, and her growth failure was recovering (weight z-score: -1.0; height z-score: -1.7). The second patient underwent sequential intestine-liver transplantation at 8 years of age due to end-stage liver disease (ESLD) and short bowel syndrome caused by massive bowel resection for internal hernia after partial external biliary diversion (PEBD) at 21 months of age. She developed severe pancreatitis induced by steroid-bolus therapy for rejection after transplantation. She died 1.7 years after intestinal transplantation due to an uncontrollable pancreatic abscess and acute respiratory distress syndrome. The third patient underwent PEBD at 15 months of age and received LT with TEBD at 15 years of age due to ESLD with hepatic encephalopathy. Throughout the perioperative period, she showed no abdominal symptoms, including diarrhea and pancreatitis. Graft biopsy at the 2-year follow-up examination revealed macrovesicular steatosis (60%) with inflammation. CONCLUSIONS: The patients showed different outcomes. Effective therapeutic options to mitigate post-LT complications in patients with PFIC1 must be considered individually.

Gallstone ileus at 17 years after living donor liver transplantation: A case report.

BACKGROUND: Gallstone ileus (GI) occurs in <0.1% of all cases of mechanical bowel obstruction. There have been a few reports of GI occurring after Kasai procedures or Roux-en-Y anastomosis for bariatric surgery. We herein report a case of GI that occurred over 17 years after liver transplantation (LT). CASE REPORT: A 33-year-old woman who had undergone living donor LT for biliary atresia at 16 years old and had been regularly followed on an outpatient basis in our hospital presented with the sudden onset of increased abdominal distension, pain, and nausea. Enhanced abdominal computed tomography showed dilatation of the intrahepatic bile duct and the whole intestinal tract of the Roux limb as well as ischemic changes near the jejuno-jejunal anastomosis. On laparotomy, a movable and hard foreign body was palpated in the intestinal tract close to the jejuno-jejunal anastomosis site. Enterotomy was performed, and a 4-cm gallstone was removed. The patient had a good postoperative course and was discharged on postoperative day 12. CONCLUSIONS: Although GI after LT is a rare complication, it may need to be differentiated as a cause of ileus. An accurate differential diagnosis and early reliable intervention for stone removal will help prevent serious bowel complication, which may lead to graft dysfunction.

Present state of intestinal transplantation in Japan.

INTRODUCTION: Intestinal transplantation (ITx) is the ultimate treatment for intestinal failure (IF). In Japan, most cases of IF are a result of pediatric disease, including secondary or congenital intestinal disease or allied disorders of Hirschsprung's disease. Here, we report the results of the Japanese ITx registry. METHODS: A web-based survey form was completed. We investigated the number, age, sex, indication, surgical procedure, immunosuppressants, postoperative course, and the effects of transplantation in patients who underwent cadaveric or living-donor ITx. RESULTS: By the end of 2022, 42 cases of ITx have been performed in 38 patients in Japan. The donor sources included cadavers (29 cases) and living donors (13 cases). The surgical method was isolated ITx (N = 40) and combined liver and ITx (n = 2). Survival rates were 92%, 73%, and 59% at 1 year, 5 years, and 10 years, respectively. Ninety percent of patients completely discontinued parenteral nutrition. Approximately 80% of the patients had a performance status of 1 or less, indicating that the QOL of patients after ITx was extremely good. CONCLUSION: The results of ITx are acceptable to treat IF patients and the QOL after transplantation is also good.

Neurological impairment in children with acute liver failure following liver transplantation-A single-center experience.

BACKGROUND: Although overall survival of ALF has improved, neurological restoration after recovery from ALF may not always be satisfactory. The purpose of this study was to investigate the occurrence and possible causes of NI in children with ALF following LT. METHODS: We retrospectively examined all children younger than 16 years old with ALF who subsequently underwent LT at our center between January 2005 and December 2016. NI was assessed in December 2016 using the six-point Pediatric Cerebral Performance Category score and was defined as any increase in the score. RESULTS: There were 62 children with median age 10 months (quartile range 5-34). The etiology of ALF was indeterminate in 47 children (75.8%). The median duration from admission to LT was 5.5 days (quartile range 4-7), and 96.8% (60/62) received living donor LT. The overall survival was 83.9% (52/62) in a median follow-up period of 4.2 years. Mild-to-moderate NI was observed in 23.1% (12/52) of the survivors. Possible causes of NI were underlying systemic disease (n = 3), perioperative brain lesion (n = 2), and unclassified (n = 7). All seven patients with unclassified NI were less than 12 months old. The unclassified NI causes were presumed to be ALF, its perioperative care, and the vulnerable infant brain. CONCLUSIONS: NI in children with ALF following LT was not rare and should be prevented. Further investigations are required to clarify the characteristics of the patients with unclassified NI.

Rescue venovenous extracorporeal membrane oxygenation for the deterioration of acute respiratory distress syndrome in pediatric liver transplantation.

BACKGROUND: Twenty percent of pediatric patients with BA develop ACLF with increased mortality while awaiting LT. Respiratory complications are common in pediatric ACLF and are associated with increased morbidity and mortality. ARDS is the most severe manifestation of acute respiratory failure with considerable risk of mortality. METHODS: A 5-month-old girl with post-Kasai BA preoperatively experienced ARDS from RSV infection while awaiting LT. She developed decompensated liver failure with shock, acute kidney injury, coagulopathy, and pulmonary hemorrhage after several episodes of sepsis over the course of 1 month in the PICU. At this stage, RSV was not detected in the patient's tracheal aspirate by real-time polymerase chain reaction. She underwent living donor LT to manage her pre-existing critical state. Following reperfusion during LT, her pre-existing ARDS rapidly deteriorated, which was alleviated by intraoperative VV ECMO. RESULTS: Severe respiratory acidosis improved rapidly following ECMO, and LT was completed uneventfully. The patient was successfully weaned off ECMO on POD 3. CONCLUSIONS: This is the first pediatric case rescued by the intraoperative application of ECMO during LT. Our case and cumulative evidence suggest that VV ECMO can serve as rescue therapy for perioperative refractory respiratory failure in pediatric LT.

Hematological and biochemical characteristics and diagnostic imaging results in acute T cell-mediated rejection after pediatric liver transplantation.

BACKGROUND: Liver biopsy is the gold standard for diagnosing TCMR after LT. However, complications caused by liver biopsy may occur especially during the immediate post-transplantation period and other effective methods for predicting TCMR have not been established. Thus, we investigated whether hematological and biochemical characteristics and Doppler ultrasonography findings are associated with acute TCMR. METHODS: A multiple logistic regression analysis was performed to identify the prognostic factors of acute TCMR, defined as a RAI ≥4. Then, a ROC curve analysis was conducted to evaluate for diagnostic performance. The relationship between prognostic factors and each histological category of RAI was investigated. RESULTS: Eighty-nine liver biopsies were performed on 85 patients between January 2012 and December 2019. The RAI of 62 (69.7%) liver biopsies was ≥4. AEC (×104 /µl), direct bilirubin level (mg/dl), and MHVV (cm/s) were found to be associated with acute TCMR (OR: 4.96, 95% CI: 1.44-17.0, p = .011; OR: 1.41, 95% CI: 1.04-1.91, p = .025; OR: 1.05, 95% CI: 1.02-1.08, p < .001, respectively). The area under the ROC curves for predicting acute TCMR was 0.86 (95% CI: 0.78-0.94). There was a correlation between AEC, direct bilirubin level, and MHVV as well as the severity of RAI. CONCLUSIONS: AEC, direct bilirubin level, and MHVV were the independent risk factors for acute TCMR. This study could provide information regarding the identification of patients requiring liver biopsy.

Surgical technique and the long-term outcomes of pediatric living donor domino liver transplantation from patients with maple syrup urine disease.

BACKGROUND: The native liver of patients with maple syrup urine disease (MSUD) (1st recipients) can be used as a graft for non-MSUD patients with end-stage liver disease (2nd recipients). This study aimed to demonstrate the optimal operational procedures and the long-term outcomes of 2nd recipients. METHODS: Six 2nd recipients of living donor domino liver transplantation (LD-DLT) (age: 42.5 [22-169] months at DLT) received a native liver as a graft from an MSUD patient at our hospital between June 2014 and April 2020. We reviewed the operational procedures and outcomes of 2nd recipients after LD-DLT. RESULTS: The 2nd recipients' original diseases included biliary atresia, congenital hepatic fibrosis, congenital protein C deficiency, familial hypercholesterolemia, hepatoblastoma, and mitochondrial hepatopathy. Five of the six recipients had a whole liver and one had a right lobe graft. The site at which the vessels of the MSUD liver were dissected prioritized the safety of the 1st recipient. At the end of follow-up, all recipients were doing well without surgical complications. The mean serum amino acid values of the 2nd recipients did not exceed the upper limit of the reference values during the long-term observation period. All patients showed normal growth while maintaining the same z-score of height and weight after LD-DLT as the preoperative level. CONCLUSION: The liver of patients with MSUD can be used safely without concern regarding long-term complications or de novo MSUD development. LD-DLT using the MSUD liver can expand the donor pool as an alternative graft in pediatric LT.

Preemptive liver transplant in two patients with primary hyperoxaluria type 1: Clinical significance of nephrolithiasis and nephrocalcinosis.

BACKGROUND: Although nephrolithiasis (NL) and nephrocalcinosis (NC) are very common features of primary hyperoxaluria type 1 (PH1), the long-term prognosis of NL and NC after preemptive liver transplantation (PLT) has not been elucidated. MATERIAL AND METHODS: We describe the cases of two chronic kidney disease (CKD) stage three patients with different clinical courses after PLT for PH1. RESULTS: The first patient underwent PLT at 7 years of age with an estimated glomerular filtration rate (eGFR) of 47.8 ml/min/1.73 m2 . Two years later, she experienced several episodes of obstructive pyelonephritis due to urolithiasis, and developed septic shock in one of these episodes. At the same time as these episodes, preexisting NL and NC progressively improved, with disappearance on X-ray disappeared at 8 years after transplantation. Her renal function has been maintained with an eGFR of 58.7 ml/min/1.73 m2 . The second patient received PLT at 10 years of age with an eGFR of 58.9 ml/min/1.73 m2 . Her renal function has been maintained with an eGFR of 65.9 ml/min/1.73 m2 . She had repeated urolithiasis which started to appear at 3 years after LT. The radiological findings still show bilateral NL and NC, but the stones in the renal pelvis have shown mild improvement. CONCLUSIONS: Regardless of the regression in NC seen on X-ray, long-term maintenance of the renal function in patients with PH1 with CKD stage 3 can be achieved with PLT. In patients with NL, there is a risk of serious complications due to posttransplant immunosuppressive therapy when obstructive pyelonephritis occurs after LT.

Quantification of Maternal Microchimeric Cells in the Liver of Children With Biliary Atresia.

ABSTRACT: Biliary atresia (BA) is a rare disorder of unknown etiology. There is a debate as to whether maternal microchimerism plays a significant role in the development of BA or in graft tolerance after liver transplantation. Here, we performed quantitative-PCR-based assays for liver tissues of children with BA and other diseases. Maternal cells were detected in 4/13 and 1/3 of the BA and control groups, respectively. The estimated number of maternal cells ranged between 0 and 34.7 per 106 total cells. The frequency and severity of maternal microchimerism were similar between the BA and control groups, and between patients with and without acute rejection of maternal grafts. These results highlight the high frequency of maternal microchimerism in the liver. This study provides no evidence for roles of microchimerism in the etiology of BA or in graft tolerance. Thus, the biological consequences of maternal microchimerism need to be clarified in future studies.