Feasibility and safety of using low-body-weight donors in pediatric liver transplantation

Small-for-size syndrome in a 9.7 kg pediatric recipient with a whole liver graft

BACKGROUND

Small-for-size syndrome (SFSS) in pediatric liver transplant recipients, particularly those weighing less than 10 kg, is rare. This report describes a case of a 15-month-old whole liver transplant recipient who suffered SFSS, and systematic literature review was performed to identify outcomes of such cases and potential risk factors for SFSS.

CASE PRESENTATION

A 15-month-old toddler with a history of biliary atresia underwent a deceased donor whole liver transplant. The graft weighed 160 g, resulting in a graft-to-recipient weight ratio (GRWR) of 1.6%. The post-operative course was complicated by SFSS, characterized by massive ascites causing hemodynamic instability and compromised hepatic artery flow. Pharmacological intervention with octreotide was initiated, and the patient eventually recovered.

CONCLUSION

In small pediatric recipients, especially those weighing less than 10 kg, the native liver body weight ratio (LBWR) is significantly higher. When selecting an appropriately sized graft for these recipients, this higher ratio should be taken into consideration. The literature review suggests that a GRWR of less than 2% is associated with a higher incidence of small-for-size syndrome in small pediatric recipients weighing less than 10 kg.

Potential of neonatal organ donation and outcome after transplantation

Organ transplantation is limited by access to suitable organs. Infant recipient waitlist mortality is increased due to the scarcity of size-matched organs. Neonatal organ donors have been proposed as an underutilized source of donor organs. However, the literature on the actual prevalence and outcome of neonatal organ donation and transplantation is fragmented and not well analyzed. This literature review aims to summarize the available literature on the potential of neonatal organ donation and to analyze published cases of neonatal organ transplantation. A systematic search of the Medline and Cochrane databases yielded 2964 articles, which were screened for eligibility. In total, 86 articles were considered eligible, of which 34 were included in the literature review: 8 articles describing the potential of neonatal organ donation programs, and 26 articles describing clinical transplantation. Current evidence suggests there is a large pool of potential neonatal organ donors. In contrast, the literature on neonatal organ donor utilization is sparse. However, case series of successful kidney, heart, liver, hepatocyte, and multivisceral transplantation using organs from neonatal donors are summarized. Although good posttransplant organ function was achieved, the use of neonatal organs is associated with increased risk of thrombosis in both kidney and liver transplantation. Neonatal organ donation is a promising alternative for expanding the current donor pool. Experience is limited, but reported patient and graft survival are acceptable and more research on the subject is warranted.

Outcome of split-liver transplantation from pediatric donors weighing 25 kg or less

The lower limit of body weight for "splitable" liver grafts remains unknown. To examine the outcome of split-liver transplantation (SLT) from pediatric donors ≤25 kg relative to conventional graft-type liver transplantation from deceased donors under corresponding conditions, a total of 158 patients who received primary liver transplantation, including 22 SLTs from donors ≤25 kg, 46 SLTs from donors >25 kg, 76 whole-liver transplantations, and 14 reduced-liver transplantations in donors ≤25 kg between January 2018 and December 2019, were included in the study. There was no significant difference in the complications, patient survival, and graft survival between each of the latter three groups and the SLT ≤25 kg group. Pediatric End-Stage Liver Disease (PELD) score was the independent predictor of graft loss (death or retransplantation). Graft weight was the independent predictor of hepatic artery thrombosis. SLT using well-selected pediatric donors ≤25 kg is an effective strategy to increase organ availability, especially for low-body-weight recipients, compared with conventional graft type from deceased donors under the condition of corresponding donor weight without increasing morbidity and mortality.

Management and outcome of hepatic artery thrombosis with whole-liver transplantation using donors less than one year of age

BACKGROUND/PURPOSE

The incidence of hepatic artery thrombosis (HAT) in recipients is high after pediatric LT using young donors. In this study we investigated the management and outcome of HAT after whole-LT using donors less than one year of age. And evaluate the safety of pediatric donors, and increase the utilization of pediatric donors overall.

METHODS

We retrospectively analyzed the clinical data encompassing children who underwent whole-liver transplantation in our department from January 2014 to December 2019. Recipients receiving a liver from a donor ≥1 month and ≤12 months were included, and a total of 110 patients were included in this study.

RESULTS

The results showed an incidence for HAT of 20% and the median time to HAT diagnosis was 3.0 (2.0, 5.3) days post-operation. Anticoagulant therapy was used for 19 cases and 94.7% of them achieved hepatic artery recanalization or collateral formation. The median time of recanalization was 12 (5, 15) days. Bile leakage and biliary strictures occurring in the HAT group were higher than in the non HAT group (13.6% vs. 1.1% and 31.8% vs. 3.4%). There were no significant differences in the survival rates of recipients or grafts among the two groups (P = 0.474, P = 0.208, respectively).

CONCLUSION

We confirmed that the incidence of HAT in LT recipients use donors less than 1 year is high, but recanalization can be performed using anticoagulant therapy. Although biliary complications increased significantly after HAT, the survival rates of patients and grafts were satisfactory.

LEVEL OF EVIDENCE

Level III.

Outflow reconstruction of left lateral graft with two widely spaced hepatic veins in pediatric living donor liver transplantation

BACKGROUND

Living donor liver transplantation using the left lateral segment of the liver is the most common type of pediatric liver transplantation. An appropriate surgical approach is crucial for decreasing the risk of vascular complications using these grafts with anatomical variations.

METHODS

Between January 2017 and December 2020, 631 living donor liver transplantations using left lateral segment grafts were performed at Tianjin First Central Hospital. The grafts from 162 (25.7%) donors have 2 hepatic vein openings. A total number of 21 transplantations using left lateral segment grafts with 2 widely spaced hepatic vein openings were performed. In group 1, the unification venoplasty technique with interposition vein graft was used at the back table for the reconstruction of hepatic vein from grafts. In group 2, dual hepatic vein reconstructions were performed, in which venoplasty of recipients' left hepatic vein, middle hepatic vein, and inferior vena cava was performed to create a large orifice for anastomosis with segment Ⅱ hepatic vein from the graft. Segment III hepatic vein from the graft was anastomosed with the recipient's right hepatic vein. The incidence, treatment, and outcomes of hepatic venous outflow obstruction were compared between the 2 groups.

RESULTS

The median follow-up time was 12.8 months. There was no significant difference in the incidence of hepatic venous outflow obstruction between the 2 groups.

CONCLUSION

Dual hepatic vein reconstruction is an alternate surgical option for grafts with 2 widely spaced hepatic veins, and it is associated with ideal graft recovery and vascular condition. However, long-term follow-up is still needed to verify the efficacy and safety of this approach.

Neonatal donation: are newborns too young to be recognized?

Neonatal organ and tissue donation is not common practice in the Netherlands. At the same time, there is a transplant waiting list for small size-matched organs and tissues. Multiple factors may contribute to low neonatal donation rates, including a lack of awareness of this option. This study provides insight into potential neonatal organ and tissue donors and reports on how many donors were actually reported to the procurement organization. We performed a retrospective analysis of the mortality database and medical records of two largest neonatal intensive care units (NICUs) in the Netherlands. This study reviewed records of neonates with a gestational age >37 weeks and weight >3000g who died in the period from January 1, 2005 through December 31, 2016. During the study period, 259 term-born neonates died in the two NICUs. In total, 132 neonates with general contra-indications for donation were excluded. The medical records of 127 neonates were examined for donation suitability. We identified five neonates with documented brain death who were not recognized as potential organ and/or tissue donors. Of the remaining neonates, 27 were found suitable for tissue donation. One potential tissue donor had been reported to the procurement organization. In three cases, the possibility of donation was brought up by parents.Conclusion: A low proportion (2%) of neonates who died in the NICUs were found suitable for organ donation, and a higher proportion (12%) were found suitable for tissue donation. We suggest that increased awareness concerning the possibility of neonatal donation would likely increase the identification of potential neonatal donors. What is Known: • There is an urgent need for very small organs and tissues from neonatal donors What is New: • A number of neonates who died in the NICU were suitable organ or/and tissue donors but were not recognized as donors. • Knowledge on neonatal donation possibilities is also important for proper counseling of parents who sometimes inquire for the possibility of organ and tissue donation.

Prophylactic Strategy Against De Novo Hepatitis B Virus Infection for Pediatric Recipients Who Receive Hepatitis B Core Antibody-Positive Liver Grafts

The goal of this study was to evaluate the efficacy of a perioperative prophylactic strategy against de novo hepatitis B virus (HBV) infection in pediatric liver transplantation (LT) recipients with hepatitis B core antibody (HBcAb)-positive grafts. A total of 482 pediatric recipients transplanted between 2013 and 2017 were enrolled, and 170 recipients received HBcAb-positive liver grafts. The overall graft and recipient survival rates in HBcAb-positive and HBcAb-negative graft recipients were 91.8% versus 91.3% and 95.3% versus 94.2% at the end of follow-up. Preoperative hepatitis B surface antibody (HBsAb) titer ≥ 1000 IU/L and postoperative HBsAb titer ≥200 IU/L were our prophylactic targets for recipients receiving HBcAb-positive grafts. While 11 recipients developed de novo HBV infection, 10 received HBcAb-positive grafts. Both the preoperative and postoperative HBsAb targets were achieved in 78 recipients, the infection rate of de novo HBV was 1.3%; 24 recipients met the preoperative target, the infection rate was 4.2%; 52 recipients met the postoperative target, the infection rate was 1.9%; and 16 recipients met neither the preoperative nor postoperative HBsAb target, 43.8% of the recipients were infected with de novo HBV, which was significantly higher than the recipients who met both or either of the preoperative and postoperative targets. Split-liver grafts positive for HBcAb showed higher risk of de novo HBV infection. Postoperative application of lamivudine to recipients whose preoperative HBsAb titer < 1000 IU/L did not show preventive effect. Out of 11 infected recipients, 3 showed seroconversion under entecavir treatment. In conclusion, the graft and recipient survival rates were similar in pediatric LT recipients receiving HBcAb-positive or HBcAb-negative grafts. Our prophylactic strategy was effective for preventing de novo HBV infection in HBcAb-positive liver graft recipients.

Successful living donor liver transplantation plus domino-auxiliary partial orthotopic liver transplantation for pediatric patients with metabolic disorders

PURPOSE

To investigate the efficacy of living donor liver transplantation (LDLT) plus domino-auxiliary partial orthotopic liver transplantation (D-APOLT) in pediatric patients with metabolic disorders.

METHODS

From May 2017 to October 2018, two patients with ornithine aminotransferase deficiency (OTCD) and one patient with type I Crigler-Najjar syndrome (CNS1) received LDLT, their livers were prepared as donors for D-APOLT. Two patients with CNS1 received domino liver grafts from OTCD patients; one OTCD patient received a domino liver graft from a CNS1 patient.

RESULTS

The mean follow-up was 26.6 months. The liver function and ammonia remained in the normal range at the end of the follow-up in all recipients. One D-APOLT patient experienced portal vein thrombosis 2 days after transplantation and required reoperation, this patient presented an imbalance of portal blood perfusion between the native and the domino liver at 8 months after liver transplant. The imbalance was improved by interventional radiology treatment. Two LDLT patients experienced early mild acute rejection.

CONCLUSIONS

The non-cirrhotic livers from pediatric patients with metabolic liver disease can be used as domino donor grafts for selected pediatric patients with different metabolic liver disease. D-APOLT achieves ideal recipient outcomes and provides a strategy to expand donor source for children.

Application of pediatric donors in split liver transplantation: Is there an age limit?

The experience of using pediatric donors in split liver transplant is exceedingly rare. We aim to investigate the outcomes of recipients receiving split pediatric grafts. Sixteen pediatric recipients receiving split liver grafts from 8 pediatric donors < 7 years were enrolled. The donor and recipient characteristics, perioperative course, postoperative complications, and graft and recipient survival rates were evaluated. The mean follow-up time was 8.0 ± 2.3 months. The graft and recipient survival rates were 100%. The liver function remained in the normal range at the end of the follow-up time in all recipients. No life-threatening complications were seen in these recipients, and the only surgery-related complication was portal vein stenosis in 1 recipient. Cytomegalovirus infection was the most common complication (62.5%). The transaminase level was significant higher in extended right lobe recipients in the early postoperative days, but the difference vanished at the end of first week; postoperative complications and graft and recipient survival rates did not differ between left and right graft recipients. Notably, the youngest split donor graft (2.7 years old) was associated with ideal recipient outcomes. Split liver transplant using well-selected pediatric donors is a promising strategy to expand pediatric donor source in well-matched recipients.