Regeneration Process of an Autologous Tissue-Engineered Trachea (aTET) in a Rat Patch Tracheoplasty Model.

The treatment of long-tracheal lesion is difficult because there are currently no viable grafts for tracheal replacement. To solve this problem, we have developed an autologous Tissue-Engineered Trachea (aTET), which is made up of collagenous tissues and cartilage-like structures derived from rat chondrocytes. This graft induced successful long-term survival in a small-animal experiment in our previous study. In this study, we investigated the regeneration process of an aTET to attain reproducible success. We prepared an aTET by using a specially designed mold and performed patch tracheoplasty with an aTET. We assigned twenty-seven rats to three groups according to the three types of patch grafts used: aTET patches (the aTET group), fresh tracheal autograft patches (the Ag group), or polylactic acid and polycaprolactone copolymer sheets (the PPc group). In each group, gross and histological evaluations were performed at 1 month (n = 3), 3 months (n = 3), and 6 months (n = 3) after implantation. We obtained high survival rates in all groups, but only the PPc group attained thick tracheal walls with granular tissues and no tracheal regeneration. On the other hand, the aTET and Ag groups reproducibly achieved complete tracheal regeneration in 6 months. So, an aTET could be a promising candidate for tracheal regeneration grafts.

Balloon dilatation for congenital esophageal stenosis associated with esophageal atresia.

PURPOSE: Congenital esophageal stenosis (CES) associated with esophageal atresia (EA) is rare, and no standard treatment has been established. We reviewed cases of EA-associated CES to assess the clinical characteristics and treatment outcomes, especially the feasibility of endoscopic dilatation. METHODS: We retrospectively examined patients with EA-associated CES. We also compared treatment outcomes of EA-associated CES with those of EA patients without CES who developed postoperative anastomotic stricture. RESULTS: Among 44 patients with EA, ten had CES (23%). Postoperative complications were not significantly different between EA patients with CES and those without CES but with anastomotic stricture. All CES patients underwent balloon dilatation as initial treatment. Eight of nine patients (89%) were successfully treated by dilatation only, and one patient underwent surgical resection. The median number of balloon dilatations for CES was five (2-17), which was higher than that for anastomotic stricture in patients without CES (p = 0.012). Esophageal perforation occurred in five patients with CES (5/9, 56%) after dilatation, but all perforations were successfully managed conservatively with an uneventful post-dilatation course. CONCLUSIONS: Twenty-three percent of patients with EA had CES. Although balloon dilatation for EA-associated CES required multiple treatments and carried a risk of perforation, balloon dilatation showed an 89% success rate and all perforations could be managed conservatively.

Plasma Concentration of Antifungal Agent Micafungin for Pediatric Living Donor Liver Transplantation.

BACKGROUND: Pediatric living-donor liver transplantation (LDLT) candidates often receive long-term antibiotic treatment. Micafungin has been used as an antifungal agent after LDLT, but the adequate dose after pediatric LDLT was unknown. Here, we report micafungin blood concentrations after pediatric LDLT and discuss its safety and adequate dosing. METHODS: Pediatric patients with data on micafungin concentrations after LDLT were identified. Those with surgical complications were excluded. All patients received standard tacrolimus-based immunosuppression. A micafungin dose of 1 mg/kg was administered once daily for 10 days starting on postoperative day (POD) 1. The trough and peak micafungin blood concentrations were evaluated on PODs 1, 4, 7, and 10. Beta D glucan levels and liver function tests were assessed to determine micafungin effectiveness and safety. RESULTS: Ten patients were enrolled, with a median age of 1.2 years. The median graft vs body weight ratio was 2.7%. The primary diseases were biliary atresia (n = 7), Alagille syndrome (n = 2), and progressive familial intrahepatic cholestasis type 2 (n = 1). Mean peak micafungin levels were 4.47, 6.27, 5.47, and 5.47 µg/mL on PODs 1, 4, 7, and 10, respectively. Mean trough levels were 2.03, 1.88, and 2.66 µg/mL on PODs 4, 7, and 10, respectively. The micafungin half-lives were 13.7, 14.7, and 14.0 hours on PODs 4, 7, and 10, respectively. Beta D glucan levels were 4.4 pg/mL and 3.7 pg/mL before and after transplantation, respectively, indicating no significant difference (P = .3). No clinical fungal infections were observed. CONCLUSION: Micafungin administration is safe and effective after pediatric LDLT.

Impact of Total Parenteral Nutrition on Preoperative Management of Pediatric Living-Donor Liver Transplantation for Biliary Atresia Under 2 Years Old.

BACKGROUND: Liver failure and gastrointestinal bleeding occur in the end-stage of biliary atresia (BA). Living-donor liver transplantation (LDLT) is a standard treatment in Japan. Our program actively provides pre-transplant total parenteral nutrition (TPN) for such patients, and here we report its efficiency and safety. METHODS: Patients with BA for whom LDLT was indicated were identified. Those with a long-term external central venous catheter and TPN, longer than 4 weeks before LDLT, were analyzed. Ascites was controlled with diuretics. TPN indications, efficacy, and complications were assessed along with patient growth, biochemical markers, and gastrointestinal bleeding. RESULTS: Fourteen patients were included in the study, of whom 8 were girls and 6 were boys. The median age at LDLT was 0.9 years. Body weight (BW) at TPN initiation averaged 6799 g, and the median serum total bilirubin was 9.5 mg per dL. The median catheterization duration was 54 days, and 1 patient received home TPN. Indications for TPN were gastrointestinal bleeding and/or massive esophageal varices in 4 patients and poor nutritional status in 10 patients. No complications were observed except for 1 catheter infection and 1 catheter occlusion. The median final body weight before LDLT was 7906 g. The mean rate of BW gain was significantly higher after TPN than before (149 vs 32 g/wk, respectively, P = .0002). Mean prothrombin time and levels of albumin, cholinesterase, and total bilirubin were not significantly different at the start and end of TPN. CONCLUSIONS: Pre-transplant TPN was safe and effective for patients with end-stage BA.

Clinical Implications of Serum Mac-2 Binding Protein in Patients After Living Donor Liver Transplantation for Biliary Atresia.

BACKGROUND: Patients who undergo pediatric living donor liver transplantation (LDLT) sometimes develop graft fibrosis. Recently, Mac-2 binding protein glycosylation-modified isomer (M2BPGi) was developed as a new marker of hepatic fibrosis progression. We performed this study to examine the relationship between serum M2BPGi levels and liver histologic findings in patients after LDLT for biliary atresia. METHODS: Patients aged <19 years who underwent LDLT for biliary atresia at our institution and followed up for at least 1 year after LDLT were eligible. There were 56 patients in this study. Pathologic findings of the last available biopsy were assessed. Portal vein (PV) stenosis was confirmed with angiography. M2BPGi levels were compared with pathologic fibrosis scores and PV stenosis findings. RESULTS: The mean age at transplant was 4.3 years. The mean observation period was 8.6 years. In terms of the degree of liver fibrosis, F0 was observed in 7 patients, F1 in 36, and F2 in 13. The median serum M2BPGi value was 0.8 cut-off index (COI) overall and 0.60 COI for F0, 0.74 COI for F1, and 1.07 COI for F2. The mean M2BPGi value in F2 was higher than that in F0 (P = .016) and F1 (P = .012). Mean serum M2BPGi values were 1.57 COI (0.29 COI) in patients with PV complications (n = 5) and 0.72 COI in patients without PV complications (n = 51) (P = .0001). CONCLUSION: M2BPGi is a novel marker for liver fibrosis in patients after pediatric LDLT. It is especially useful for follow-up of pediatric patients after LDLT to support liver biopsy interpretation.

Potential risks associated with laparoscopic gastrostomy in patients with the COL4A1 variant: Two case reports.

The COL4A1 (collagen Type 4 alpha1) pathogenic variant is associated with porencephaly and schizencephaly and accounts for approximately 20% of these patients. This gene variant leads to systemic microvasculopathy, which manifests as brain, ocular, renal, and muscular disorders. However, only a few patients with surgical interventions have been reported and the potential surgical risks are unknown. Here, we present the cases of two female patients between 7 and 8 years of age who were diagnosed with the COL4A1 variant and underwent laparoscopy-assisted percutaneous endoscopic gastrostomy (LAPEG) for oral dysphagia. Their primary brain lesions were caused by porencephaly and paralysis, which are caused by multiple cerebral hemorrhages and infarctions, and both patients had refractory epileptic complications. Although LAPEG was successfully performed in both patients without any intraoperative complications, one patient developed alveolar hemorrhage postoperatively and required mechanical ventilation. Thus, careful perioperative management of patients with the COL4A1 variant is important.

Regenerative medicine: current research and perspective in pediatric surgery.

The field of regenerative medicine, encompassing several disciplines including stem cell biology and tissue engineering, continues to advance with the accumulating research on cell manipulation technologies, gene therapy and new materials. Recent progress in preclinical and clinical studies may transcend the boundaries of regenerative medicine from laboratory research towards clinical reality. However, for the ultimate goal to construct bioengineered transplantable organs, a number of issues still need to be addressed. In particular, engineering of elaborate tissues and organs requires a fine combination of different relevant aspects; not only the repopulation of multiple cell phenotypes in an appropriate distribution but also the adjustment of the host environmental factors such as vascularisation, innervation and immunomodulation. The aim of this review article is to provide an overview of the recent discoveries and development in stem cells and tissue engineering, which are inseparably interconnected. The current status of research on tissue stem cells and bioengineering, and the possibilities for application in specific organs relevant to paediatric surgery have been specifically focused and outlined.

Tension-free thoracoscopic repair of congenital diaphragmatic hernia combined with a percutaneous extracorporeal closure technique: how to do it.

PURPOSE: Thoracoscopic repair (TR) of congenital diaphragmatic hernia (CDH) is associated with a higher recurrence rate than the conventional open method. We evaluated the effectiveness of our strategy for quality improvement, named "tension-free TR of CDH". METHODS: The subjects of this retrospective analysis were 11 consecutive patients with CDH who underwent TR at our hospital between 2017 and 2021. Tension-free TR of CDH included the proactive use of an oversized patch for dome-shaped reconstruction and gapless suturing. We developed a percutaneous extracorporeal closure technique for secure suturing using a commercially available needle. RESULTS: Patch repair was performed in 8 (73%) patients and none required conversion to open surgery because of technical difficulties. Recurrence developed in one patient (9%), who underwent successful reoperation via TR. All patients had an uneventful postoperative course. CONCLUSION: Tension-free TR combined with extracorporeal closure could reduce the difficulty of suturing and the risk of recurrence of CDH.

Treatment and follow-up of late onset intra hepatic bile duct stones in congenital biliary dilatation.

PURPOSE: The postoperative course after surgery for congenital biliary dilatation (CBD) has some complications. Intrahepatic bile duct (IHBD) stones were known as a late complication. We report on the treatment and long-term follow-up of postoperative IHBD stones in our department. METHODS: Patients who underwent CBD surgery at age 15 years or younger in our department were identified. Those followed up for 5 years or more were enrolled. Annual blood chemistry tests and abdominal ultrasonography were performed. Each patient's surgical procedure, IHBD stone diagnosis, treatments, and outcomes were retrospectively assessed. RESULTS: Fifty-one patients were analyzed. The median age at the last visit was 24 years (range 7-45 years), and the median age at CBD surgery was 3 years. Eight patients (16%) developed late-onset IHBD stones. The median age at onset was 25 years, and the median duration after surgery was 20 years. The initial treatment was double-balloon enteroscopy (DBE) in 4 cases, which resulted in stone removal in 3 of the 4 patients (75%). CONCLUSION: Since CBD may cause late-onset IHBD stones, continuous follow-up is required even in adulthood. In this study, DBE was effective and minimally invasive, and it is recommended as the initial treatment.

Early detection of liver fibrosis with serum Mac-2 binding protein glycosylation-modified isomer (M2BPGi) during follow-up intestinal failure patients without intestinal failure-associated liver disease (IFALD).

PURPOSE: Mac-2 binding protein glycosylation-modified isomer (M2BPGi) is a new marker for hepatic fibrosis progression. We examined the relationship between serum M2BPGi levels and liver histological findings in intestinal failure (IF) patients without IF-associated liver disease (IFALD). METHODS: This study included IF patients without IFALD followed at our hospital. All patients underwent routine liver biopsies per protocol every 1-2 years. We examined M2BPGi levels and histological findings in relation to aspartate aminotransferase (AST) to platelet ratio index, fibrosis-4 index, and AST/ALT ratio. Liver fibrosis was evaluated based on the METAVIR score. RESULTS: Total 18 liver biopsies out of eight patients were included. The median age was 11.5 years. Mean M2BPGi was 0.44 cutoff index (COI) in patients with F0 fibrosis, 0.78 COI in patients with F1 fibrosis and 1.63 COI in patients with F2 fibrosis. Mean M2BPGi was significantly higher in patients with F2 versus F1 or F0 fibrosis (P < 0.016 and P < 0.028, respectively). M2BPGi levels were more strongly correlated with fibrosis stage than with other conventional fibrosis markers. CONCLUSION: Serum M2BPGi is a novel marker of liver fibrosis in patients with IF. It is useful for follow-up prior to IFALD. Serum M2BPGi levels can support the interpretation of liver status.

Ileocecal valve-sparing surgery for duplication cysts in the terminal ileum: two case reports and literature review.

BACKGROUND: Duplication cysts close to the ileocecal valve are usually treated with ileocecal resection. However, loss of the ileocecal valve will lead to problems, especially in infants. Mucosectomy of the cyst would be a better alternative that preserves the ileocecal valve. We report two cases of duplication cyst in the terminal ileum successfully treated with mucosectomy. CASE PRESENTATION: Case 1. A 3-month-old boy with bilious emesis and abdominal distention was referred to our hospital with a diagnosis of small bowel obstruction caused by an abdominal cyst. Computed tomography revealed a cystic mass compressing the terminal ileum and causing mechanical small bowel obstruction. His general condition deteriorated quickly; emergency laparotomy was performed. Although the small intestines were dilated and partially twisted, there was no necrosis. Following intestinal decompression, a cystic mass adjacent to the terminal ileum was confirmed on the mesenteric side. Cyst mucosectomy was performed to preserve the ileocecal valve. CASE 2: A 5-month-old boy with sudden onset of hematochezia was referred to our hospital with a diagnosis of intussusception. Following unsuccessful contrast enemas, emergency surgery was performed. A cystic mass adjacent to the terminal ileum was confirmed; there was no intussusception. Cyst mucosectomy was performed. Both patients had an uneventful postoperative course. CONCLUSIONS: Cyst mucosectomy, which preserves the ileocecal valve, is safe and effective for treating duplication cysts in the terminal ileum.

Laparoscopic Percutaneous Extraperitoneal Closure for Hydrocele of the Canal of Nuck in Children.

Background: Hydrocele of the canal of Nuck (HCN) is a rare cause of inguinal swelling in women. The optimal surgical procedure for HCN in children remains unclear. To assess the safety and efficacy of laparoscopic percutaneous extraperitoneal closure (LPEC) for HCN in a pediatric population, a retrospective study was conducted. In addition, to clarify the pathogenesis of HCN, we assessed the morphological findings of the internal inguinal ring (IIR). Materials and Methods: We retrospectively analyzed 10 consecutive female patients with HCN who underwent LPEC at our hospital between January 2010 and May 2020. Age, operative time, and complications were recorded. Concerning the findings of the IIR, we classified the morphological features as follows: Type 1 (flat), Type 2 (narrow patent processus vaginalis [PPV] with a peritoneal veil), and Type 3 (widely opening PPV). Results: The median age of patients who underwent LPEC was 3 (1-12) years. Although 2 patients showed contralateral inguinal hernia (IH), there were no cases of ipsilateral IH. All patients showed ipsilateral PPV, and the morphological features of the IIR were mostly classified as Type 3 (70%). In total, 6 of 8 HCN cases without preoperatively diagnosed contralateral IH had contralateral PPV (75%), and all were closed by LPEC. All operations were accomplished laparoscopically, and the postoperative course was uncomplicated, with no recurrences observed during the study period. Conclusions: LPEC is a safe and simple surgical approach to repair the HCN in children with minimal complications.

Clinical implications of serum autotoxin in regular follow up after pediatric living donor liver transplantation for biliary atresia.

BACKGROUND: Pediatric patients sometimes develop graft fibrosis after living donor liver transplant (LDLT). Autotaxin is a recently developed serum marker for hepatic fibrosis. We studied the relationship between serum autotaxin levels and histological findings in patients after LDLT for biliary atresia (BA). METHODS: Information on patients aged <19 years who received LDLT for BA and were followed for at least 1 year after LDLT was gathered. Autotaxin levels were compared with pathological fibrosis scores. RESULTS: The study included 52 patients, of whom 4 patients had no fibrosis (F0), 36 patients had F1 fibrosis, and 12 patients had F2. The median serum autotaxin level was 0.89 mg/L. In patients with portal vein (PV) complications such as stenosis or thrombosis (n = 7), the mean autotoxin level was 1.25 mg/L compared with 0.95 mg/L in patients without PV complications (p = 0.004). Among patients without PV complications, the mean autotaxin level was 0.90, 0.88, and 1.18 mg/L in F0, F1, and F2 fibrosis, respectively. The mean autotaxin was higher in F2 fibrosis than in F0 or F1 fibrosis (p<0.05). Autotoxin had a high area under the curve (0.86) with the cut-off level of 0.897 mg/L. CONCLUSION: Serum autotaxin is a novel marker for liver fibrosis in patients after pediatric LDLT for BA. TYPE OF STUDY: Study of Diagnostic Test. LEVEL OF EVIDENCE: Level II.

Factors Associated With Adverse Outcomes Following Duodenal Atresia Surgery in Neonates: A Retrospective Study.

Objectives There is limited evidence on the infants' postoperative complications who have undergone surgical repair of duodenal atresia and stenosis. This study aimed to identify the factors associated with poor surgical outcomes after the initial repair. Methods We retrospectively reviewed the data of 82 patients who underwent surgery for duodenal atresia and stenosis between January 1994 and December 2013 at our institution. Gestational age, birth weight, fetal growth, and other associated anomalies were recorded. Multivariate regression analyses were used to identify the factors associated with surgical outcomes, including postoperative complications and time to full oral intake. Results The median gestational age was 37.6 weeks, with 30 (37%) preterm (<37 weeks) and 11 (13%) early preterm (<34 weeks) infants. The median birth weight was 2531 g, with 27 (33%) patients < 2000 g and 10 (12%) patients < 1500 g. Postoperative surgical complications were identified in 18 (22%) cases, of which 12 (15%) required additional operations. Multivariate regression analysis revealed that a combination of very low birth weight (<1500 g) and early preterm was significantly associated with both surgical and non-surgical postoperative complications (p = 0.0028 and 0.021, respectively) and a prolonged time to full oral intake postoperatively (p = 0.013). Conclusion Very low birth weight and early preterm were significantly associated with postoperative complications and a prolonged time to full oral intake.

Development of a porcine acellular bladder matrix for tissue-engineered bladder reconstruction.

PURPOSE: Enterocystoplasty is adopted for patients requiring bladder augmentation, but significant long-term complications highlight need for alternatives. We established a protocol for creating a natural-derived bladder extracellular matrix (BEM) for developing tissue-engineered bladder, and investigated its structural and functional characteristics. METHODS: Porcine bladders were de-cellularised with a dynamic detergent-enzymatic treatment using peristaltic infusion. Samples and fresh controls were evaluated using histological staining, ultrastructure (electron microscopy), collagen, glycosaminoglycans and DNA quantification and biomechanical testing. Compliance and angiogenic properties (Chicken chorioallantoic membrane [CAM] assay) were evaluated. T test compared stiffness and glycosaminoglycans, collagen and DNA quantity. p value of < 0.05 was regarded as significant. RESULTS: Histological evaluation demonstrated absence of cells with preservation of tissue matrix architecture (collagen and elastin). DNA was 0.01 µg/mg, significantly reduced compared to fresh tissue 0.13 µg/mg (p < 0.01). BEM had increased tensile strength (0.259 ± 0.022 vs 0.116 ± 0.006, respectively, p < 0.0001) and stiffness (0.00075 ± 0.00016 vs 0.00726 ± 0.00216, p = 0.011). CAM assay showed significantly increased number of convergent allantoic vessels after 6 days compared to day 1 (p < 0.01). Urodynamic studies showed that BEM maintains or increases capacity and compliance. CONCLUSION: Dynamic detergent-enzymatic treatment produces a BEM which retains structural characteristics, increases strength and stiffness and is more compliant than native tissue. Furthermore, BEM shows angiogenic potential. These data suggest the use of BEM for development of tissue-engineered bladder for patients requiring bladder augmentation.

Early Use of Everolimus as a Third Immunosuppressive Agent for Intestinal Transplantation: A Report of 2 Cases.

BACKGROUND: In patients with intestinal transplantation (ITx), renal function is easily impaired because of long-term parenteral nutrition and side effects of tacrolimus. Everolimus was used in patients with renal insufficiency in our study. METHODS: We administered everolimus as a third immunosuppressive agent in addition to tacrolimus and steroids for renal sparing in patients who received ITx. We assessed everolimus levels, complications, and renal function. RESULTS: Two patients received everolimus after ITx. Patient 1 was a 13-year-old boy who underwent ITx for an allied disorder of Hirschsprung's disease. After induction therapy with rabbit antithymocyte globulin, maintenance therapy consisted of tacrolimus and steroids. Everolimus was introduced 3 months after ITx for renal sparing. Seven months later, the patient required partial intestinal graft resection owing to bowel obstruction. Everolimus was suspended for only 2 weeks. Four years after ITx, the trough level of tacrolimus was maintained at 3 to 5 ng/mL. The trough level of everolimus was maintained at 3 to 5 ng/mL. Patient 2 was a 32-year-old man who underwent deceased ITx for short gut syndrome. Induction and maintenance immunosuppression was the same as for patient 1. Everolimus was introduced 1 month after surgery. Two years after ITx, trough levels of tacrolimus and everolimus were the same as in patient 1. No rejection was observed in either patient, and renal function was well maintained. We observed no side effects caused by everolimus. CONCLUSIONS: Everolimus could be used safely and effectively after ITx. Early use of everolimus after ITx did not affect wound healing.

Long-Term Outcome of Portal Vein Stenting After Pediatric Living Donor Liver Transplantation.

BACKGROUND: Portal vein (PV) stenosis is sometimes seen in pediatric living donor liver transplantation (LDLT). PV stents have been attempted in adults with persistent stenosis. However, long-term usefulness of PV stenting is unknown because stents do not expand with growth. We investigated the effect and long-term outcome of PV stenting for stenosis after pediatric LDLT. METHODS: We included patients aged <18 years who underwent LDLT from 1998 to 2020 and who underwent PV stenting for stenosis. We assessed age at procedure, stent complications, and long-term outcomes. RESULTS: Five patients underwent PV stent placement. The median age at LDLT was 10 years (range, 0.8-18.1 years). The median interval between LDLT and stent placement was 25 months. The median age at stent placement was 16 years (range, 3-20 years). The median body weight was 38 kg (range, 13-63 kg). The median stent diameter was 8 mm. The median observation period after stent placement was 8 years. On average, body weight increased 1.6 times. One complication associated with stent placement was PV thrombosis, which resulted in stent failure, but we observed no portal hypertension. In the other 4 patients, the stent has remained functioning, and there was no clinical evidence of portal hypertension. CONCLUSIONS: PV stents are effective for intractable PV stenosis in children. PV stents were successfully placed in children as young as 3 years old and weighing 13 kg. Our data suggests that a stent placed in young children does not cause portal hypertension as patients grow.

Long-Term Outcome After Tacrolimus-Related Neurotoxicity in Pediatric Living Donor Liver Transplantation.

BACKGROUND: Tacrolimus-related neurotoxicity is a serious complication. Posterior reversible encephalopathy syndrome, which is severe neurotoxicity after pediatric living donor liver transplantation (LDLT), is a medication-induced complication related to calcineurin inhibitors. The purpose of this study was to evaluate the long-term outcome of tacrolimus-related neurotoxicity after pediatric LDLT. METHODS: Pediatric patients who underwent LDLT between 2007 and 2020 at our institution and developed neurologic symptoms with tacrolimus were included in the study. Tacrolimus-related encephalopathy was defined as encephalopathy that resolved after tacrolimus was discontinued. All patients received tacrolimus and a steroid for immunosuppression starting just after LDLT. RESULTS: During the study period, 128 patients underwent LDLT. All patients received tacrolimus and a steroid. Six patients (5%) developed tacrolimus-related encephalopathy. The median age at transplant was 1.6 years. The original diseases were biliary atresia (n = 5) and progressive familial intrahepatic cholangiopathy type 2 (n = 1). Patients developed encephalopathy at a median of 9 days after LDLT. All patients recovered with conversion to cyclosporine. Posterior reversible encephalopathy syndrome was confirmed by magnetic resonance imaging in 3 patients. The mean tacrolimus level at encephalopathy was 11 ng/dL (range, 5.6-14.6 ng/dL). White blood cell count elevation was observed in all patients. One patient died of pancreatitis. Surviving patients (n = 5) were followed for a median of 9 years. All patients resumed tacrolimus a median of 8 months from onset. No neurologic complications were observed after resuming tacrolimus. CONCLUSION: We observed tacrolimus-induced encephalopathy in 5% of patients after pediatric LDLT. Patients can resume tacrolimus safely without further neurologic symptoms.

A Retransplant Case for Hepatopulmonary Syndrome Without Liver Cirrhosis or Portosystemic Shunt After Living-Donor Liver Transplantation: A Case Report.

Hepatopulmonary syndrome (HPS) is a disease of gas exchange caused by intrapulmonary shunting secondary to liver disease-associated intrapulmonary vascular dilation. HPS is characterized by the triad of cirrhosis, chronic liver disease, or portosystemic shunting (PSS); arterial hypoxemia; and intrapulmonary arteriovenous shunting in the absence of a primary cardiopulmonary anomaly. We encountered a rare case of HPS without liver disease or PSS. The patient was an 8-year-old girl who underwent living donor liver transplantation (LDLT) shortly after developing fulminant hepatitis at 11 months of her age. Eight years after LDLT, hypoxemia and shortness of breath developed. The shunt ratio on 99mTc-macroaggregated albumin (MAA) lung perfusion scintigraphy (99mTc-MAA lung scan) was 32%. The patient had no cardiopulmonary disease, so we diagnosed her illness as HPS. We did not find cirrhosis, chronic liver disease, or PSS as a cause of HPS. We thought the graft was the cause of HPS. A second transplantation was planned. One year after the diagnosis of HPS, the shunt ratio on 99mTc-MAA lung scan worsened to 42%, digital clubbing appeared, and hypoxemia was worsening. Thus, we performed a second LDLT. After LDLT the shunt ratio on 99mTc-MAA lung scan normalized (6%) and cyanosis resolved. We determined that the graft was the cause of HPS; the typical causes of HPS were not clearly revealed in the histologic examination of the second liver explant. Acute rejection occurred twice after LDLT, so we speculated that HPS occurred because the graft became stressed over the long term.

Impact of Monosegment Graft Use for Infants in Pediatric Living Donor Liver Transplantation.

BACKGROUND: Left lateral segment grafts are generally used for very young pediatric patients undergoing living donor liver transplantation (LDLT). Recently, graft reduction techniques were developed for LDLT. Monosegment grafting has been used in newborns. The aim of this study was to determine the usefulness of monosegment grafting for infants. METHODS: Recipients <2 years of age who underwent LDLT with a monosegment graft between 2010 and 2020 were gathered. Parents comprised all LDLT donors. A segment 2 monosegment graft was resected as a graft from the donor. Standard liver volume (SLV) was estimated using Urata's equation. Graft type, graft weight (GW), and native liver weight were assessed. RESULTS: Eight patients were included in the study. Original diseases consisted of biliary atresia (n = 6) and fulminant hepatitis (n = 2). Final graft type included monosegment (n = 5) and reduced monosegment (n = 3). Median final GW/body weight after reduction was 3% (range, 2%-3.4%). Median native liver weight/SLV was 134% except in patients with fulminant hepatitis. Median pre-reduction graft volume (GV)/estimated GV was 113% (range, 60%-208%). Median pre-reduction GV/SLV of monosegment grafts that required reduction (n = 3) was 109% (range, 106%-121%). Median final reduced graft GV/SLV was 80% (range, 74%-91%). Complications due to large-for-size grafts were not observed. One case of bile leakage due to graft reduction occurred as a complication. Grafts were functioning well with the exception of one graft loss due to antibody-mediated rejection. CONCLUSION: Estimated GV in infants varies widely. Monosegment grafting can be useful for infants as well as newborns.