An appraisal of technical variant grafts compared to whole liver grafts in pediatric liver transplant recipients: Multicenter analysis from the SPLIT registry

Efficiency of machine perfusion in pediatric liver transplantation

Liver transplantation is the only life-saving procedure for children with end-stage liver disease. The field is however heterogenic with various graft types, recipient age, weight, and underlying diseases. Despite recently improved overall outcomes and the expanded use of living donors, waiting list mortality remains unacceptable, particularly in small children and infants. Based on the known negative effects of elevated donor age, higher body mass index, and prolonged cold ischemia time, the number of available donors for pediatric recipients is limited. Machine perfusion has regained significant interest in the adult liver transplant population during the last decade. Ten randomized controlled trials are published with an overall advantage of machine perfusion techniques over cold storage regarding postoperative outcomes, including graft survival. The concept of hypothermic oxygenated perfusion (HOPE) was the first and only perfusion technique used for pediatric liver transplantation today. In 2018 the first pediatric candidate received a full-size graft donated after circulatory death with cold storage and HOPE, followed by a few split liver transplants after HOPE with an overall limited case number until today. One series of split procedures during HOPE was recently presented by colleagues from France with excellent results, reduced complications, and better graft survival. Such early experience paves the way for more systematic use of machine perfusion techniques for different graft types for pediatric recipients. Clinical reports of pediatric liver transplants with other perfusion techniques are awaited. Strong collaborative efforts are needed to explore the effect of perfusion techniques in this vulnerable population impacting not only the immediate posttransplant outcome but the development and success of an entire life.

HOPE Mitigates Ischemia-Reperfusion Injury in Ex-Situ Split Grafts: A Comparative Study With Living Donation in Pediatric Liver Transplantation

Optimizing graft preservation is key for ex-situ split grafts in pediatric liver transplantation (PSLT). Hypothermic Oxygenated Perfusion (HOPE) improves ischemia-reperfusion injury (IRI) and post-operative outcomes in adult LT. This study compares the use of HOPE in ex-situ partial grafts to static cold storage ex-situ partial grafts (SCS-Split) and to the gold standard living donor liver transplantation (LDLT). All consecutive HOPE-Split, SCS-Split and LDLT performed between 2018-2023 for pediatric recipients were included. Post-reperfusion syndrome (PRS, drop ≥30% in systolic arterial pressure) and reperfusion biopsies served as early indicators of IRI. We included 47 pediatric recipients (15 HOPE-Split, 17 SCS-Split, and 15 LDLT). In comparison to SCS-Split, HOPE-Split had a significantly shorter cold ischemia time (CIT) (470min vs. 538 min; p =0.02), lower PRS rates (13.3% vs. 47.1%; p = 0.04) and a lower IRI score (3 vs. 4; p = 0.03). The overall IRI score (3 vs. 3; p = 0.28) and PRS (13.3% vs. 13.3%; p = 1) after HOPE-Split were comparable to LDLT, despite a longer CIT (470 min vs. 117 min; p < 0.001). Surgical complications, one-year graft, and recipient survival did not differ among the groups. In conclusion, HOPE-Split mitigates early IRI in pediatric recipients in comparison to SCS-Split, approaching the gold standard of LDLT.

Revisiting the forgotten "full-right full-left" liver division: Simplified technique and new strategical considerations for clinical implementation in Italy

BACKGROUND

Full-right/full-left liver splitting was introduced early in the 90s as part of the great wave of technical innovations that characterized that decade. One approach was to divide the liver on the right of the Cantlie's line and leave the middle hepatic vein with the left graft, with both grafts allocated to adults. Both grafts had some functional disadvantages and exposed the adult recipients to some early hepatic dysfunction, and the results were not great. An alternative approach consisted of an ex situ division of the liver, exactly along Cantlie's line, thus sharing the middle hepatic vein between the two grafts. None of these two techniques were really adopted, and there has been nearly no transplantation of this type in the last decade worldwide.

METHOD AND RESULTS

The authors propose a variation of the latter technique that was used recently with success: The division of the liver is made simpler; the two grafts are prepared ex situ and need a simple vascular reconstruction (one venous patch on each graft); and the grafts can be implanted using very standard techniques.

CONCLUSION

Because candidates for liver transplantation weighing 25-60 kg (old children, teenagers, and some small adults) are often at some disadvantage in getting size-matched livers (this range of weight is less represented in the donor population), implementing the latter technique would help provide adequate grafts for them. In Italy, where many livers offered for splitting are not used, there would be ample room for implementing this option within the actual donor pool and allocation system.

Comparative analysis of whole vs. split liver transplantation in infants

BACKGROUND

Liver transplantation (LT) in infants can be challenging due to their small size and small vasculature. Although both whole LT (WLT) and split LT (SLT) have been described in infants, the head-to-head comparison of these techniques in this population is sparse.

METHODS

We retrospectively analyzed the records of all patients with age ≤1 year at Indiana University between 2016 and 2022. All SLT were left lateral segment grafts split in situ.

RESULTS

A total of 24 infants were transplanted, with 11 SLT and 13 WLT. The median follow-up time was 52.1 months. Donor and recipient characteristics were comparable except for donor age (19 years vs. 2 years; p < .01) and weight (64 kg vs. 14.2 kg; p < .01). Early allograft dysfunction, primary nonfunction, and hepatic artery thrombosis developed more frequently in the WLT group. There were no biliary complications. There were two early deaths (2 and 4 days) in the WLT group. One-year graft survival (100% vs. 77%; p = .10) and patient survival (100% vs. 85%; p = .18) were numerically higher in the SLT group.

CONCLUSIONS

SLT with LLS offers a safe and viable option for liver transplantation in infants and is associated with a trend toward superior outcomes. SLT should be considered as a strategy to reduce waitlist times for infants in the absence of small, deceased donors for WLT.

The Factors Affecting Mortality After Pediatric Liver Transplantation and Long-Term Survival Outcomes: A Single Center Experience

BACKGROUND

Liver transplantation (LT) is a treatment modality in the pediatric population for several diseases like biliary atresia, metabolic liver disease, hepatoblastoma, and so on. According to the Organ Procurement and Transplantation Network, 5-year survival was reported as 85.4% to 93.5% by age after pediatric liver transplantation (PLT). This study aimed to evaluate our single-center experience of PLT by analyzing long-term results, comparing the outcomes with the literature, and identifying predictors of patient survival.

METHODS

The data of 40 patients who underwent LT at <18 years of age between June 2015 and June 2021 were studied retrospectively. Recipient characteristics such as age, sex, etiology of liver disease follow-up time, postoperative vascular and biliary complications, and donor characteristics were evaluated.

RESULTS

There were 20 (50%) girls and 20 (50%) boys, and the median age was 42 (IQR = 9-117) months. The most common indications of LT were biliary disorders (45%). A whole liver graft was used in 7 (17%), a right lobe graft in 9 (23%), a left lobe graft in 4 (10%), and a left lateral lobe graft in 20 (50%) of the recipients. The 1-, 3-, 5-, and 7-year survival rates were 85%, 82.1%, 82.1%, and 82.1%, respectively. The multivariate survival analysis revealed that the pediatric end-stage liver disease score, hepatic artery thrombosis, and portal vein thrombosis are associated with overall mortality.

CONCLUSION

In conclusion, our long-term survival is similar to the literature, with satisfactory results. However, reducing the vascular complication rates can provide superior results on PLT.