Status and Current Problems in the Allocation System for Pediatric Liver Transplantation in Korea

Fates of retained hepatic segment IV and its prognostic impact in adult split liver transplantation using an extended right liver graft

PURPOSE

When splitting a liver for adult and pediatric graft recipients, the retained left medial section (S4) will undergo ischemic necrosis and the right trisection graft becomes an extended right liver (ERL) graft. We investigated the fates of the retained S4 and its prognostic impact in adult split liver transplantation (SLT) using an ERL graft.

METHODS

This was a retrospective analysis of 25 adult SLT recipients who received split ERL grafts.

RESULTS

The mean model for end-stage liver disease (MELD) score was 27.3 ± 10.9 and graft-recipient weight ratio (GRWR) was 1.98 ± 0.44. The mean donor age was 26.5 ± 7.7 years. The split ERL graft weight was 1,181.5 ± 252.8 g, which resulted in a mean GRWR of 1.98 ± 0.44. Computed tomography of the retained S4 parenchyma revealed small ischemic necrosis in 16 patients (64.0%) and large ischemic necrosis in the remaining 9 patients (36.0%). No S4-associated biliary complications were developed. The mean GRWR was 1.87 ± 0.43 in the 9 patients with large ischemic necrosis and 2.10 ± 0.44 in the 15 cases with small ischemic necrosis (P = 0.283). The retained S4 parenchyma showed gradual atrophy on follow-up imaging studies. The amount of S4 ischemic necrosis was not associated with graft (P = 0.592) or patient (P = 0.243) survival. A MELD score of >30 and pretransplant ventilator support were associated with inferior outcomes.

CONCLUSION

The amount of S4 ischemic necrosis is not a prognostic factor in adult SLT recipients, probably due to a sufficiently large GRWR.

Prognosis of Split Liver Transplantation Compared with Whole Liver Transplantation in Adult Patients: Single-center Results under the Korean MELD Score-based Allocation Policy

BACKGROUND

Split liver transplantation (SLT) has been occasionally performed in Korea. This study compared the incidence and prognosis of SLT with whole liver transplantation (WLT) in adult patients.

METHODS

Between June 2016 and November 2019, 242 adult patients underwent a total of 256 deceased donor liver transplantation operations. SLT was performed in 7 patients (2.9%).

RESULTS

The mean age of SLT donors was 29.7 ± 7.4 years, and the mean age of recipients was 55.7 ± 10.6 years, with the latter having a mean model for end-stage liver disease score of 34.6 ± 3.1. Mean split right liver graft weight was 1,228.6 ± 149.7 g and mean graft-recipient weight ratio was 1.97 ± 0.39. Of the seven SLT recipients, Korean Network for Organ Sharing (KONOS) status was one in status 1, one in status 2 and five in status 3. The graft (P = 0.72) and patient (P = 0.84) survival rates were comparable in the SLT and WLT groups. Following propensity score matching, graft (P = 0.61) and patient (P = 0.91) survival rates remained comparable in the two groups. Univariate analysis showed that pretransplant ventilator support and renal replacement therapy were significantly associated with patient survival, whereas KONOS status category and primary liver diseases were not. Multivariate analysis showed that pretransplant ventilator support was an independent risk factor for patient survival.

CONCLUSION

Survival outcomes were similar in adult SLT and WLT recipients, probably due to selection of high-quality grafts and low-risk recipients. Prudent selection of donors and adult recipients for SLT may expand the liver graft pool for pediatric patients without affecting outcomes in adults undergoing SLT.

Survival Outcomes in Split Compared With Whole Liver Transplantation

Split-liver transplantation (SLT) should be cautiously considered because the right trisection (RTS) graft can be a marginal graft in adult recipients. Herein, we analyzed the outcomes of RTS-SLT in Korea, where >75% of adult liver transplantations are performed with living donor liver transplantation. Among 2462 patients who underwent deceased donor liver transplantations (DDLTs) from 2005 to 2014, we retrospectively reviewed 86 (3.5%) adult patients who received a RTS graft (RTS-SLT group). The outcomes of the RTS-SLT group were compared with those of 303 recipients of whole liver (WL; WL-DDLT group). Recipient age, laboratory Model for End-Stage-Liver Disease (L-MELD) score, ischemia time, and donor-to-recipient weight ratio (DRWR) were not different between the 2 groups (P > 0.05). However, malignancy was uncommon (4.7% versus 36.3%), and the donor was younger (25.2 versus 42.7 years) in the RST-SLT group than in the WL-DDLT group (P < 0.05). The technical complication rates and the 5-year graft survival rates (89.0% versus 92.8%) were not different between the 2 groups (P > 0.05). The 5-year overall survival (OS) rate (63.1%) and graft-failure-free survival rate (63.1%) of the RTS-SLT group were worse than that of the WL-DDLT group (79.3% and 79.3%; P < 0.05). The factors affecting graft survival rates were not definite. However, the factors affecting OS in the RTS-SLT group were L-MELD score >30 and DRWR ≤1.0. In the subgroup analysis, OS was not different between the 2 groups if the DRWR was >1.0, regardless of the L-MELD score (P > 0.05). In conclusion, a sufficient volume of the graft estimated from DRWR-matching could lead to better outcomes of adult SLTs with a RTS graft, even in patients with high L-MELD scores.

The rate of hepatic artery complications is higher in pediatric liver transplant recipients with metabolic liver diseases than with biliary atresia

BACKGROUND

Liver transplantation (LT) is an excellent treatment option for patients with biliary atresia (BA) who fail portoenterostomy surgery. LT is also increasingly performed in patients with metabolic liver diseases. This study compared the outcomes in pediatric patients who underwent LT for metabolic liver diseases and BA.

BASIC PROCEDURES

Data from 237 pediatric patients who underwent primary LT at Seoul National University Hospital from 1988 to 2015, including 33 with metabolic liver diseases and 135 with BA, were retrospectively analyzed.

MAIN FINDINGS

Compared with children with BA, children with metabolic liver diseases were significantly older at the time of LT (121.3 vs. 37.3 months; P < 0.001), and had lower Child-Pugh (7.1 vs. 8.4; P = 0.010) and Pediatric End-stage Liver Disease (6.5 vs. 12.8; P = 0.042) scores. Overall survival rates were similar (87.8% vs. 90.8%; P = 0.402), but hepatic artery (HA) complications were significantly more frequent in children with metabolic liver diseases (12.1% vs. 1.5%; P = 0.014).

PRINCIPAL CONCLUSION

Despite similar overall survival, children with metabolic liver diseases had a higher rate of HA complications.

TYPE OF SUBMISSION

Original article, Case control study, Retrospective.

EVIDENCE LEVEL

III.

Survival rates among patients awaiting deceased donor liver transplants at a single high-volume Korean center

BACKGROUND

Since the establishment of the Korean Network for Organ Sharing (KONOS) in 2000, thousands of patients have been enrolled on the waiting list, but only a small proportion have received a deceased donor liver transplantation. This report on waiting list mortality in Korea based on data from a single institution.

METHODS

The 1772 patients enrolled on the waiting list between February 2000 and December 2011 either have not yet received at the time of analysis or have died before receiving an organ. Survival information was obtained in February 2012 by reviewing medical records or by telephone. We excluded patients who died immediately after enrollment or after retransplantation.

RESULTS

Primary diagnoses of those awaiting transplantation were hepatitis B virus-associated cirrhosis (63.7%), alcoholic liver disease (14.3%), hepatitis C virus-associated cirrhosis (13.8%), and acute liver failure due to other causes (8.1%). The priority status of patients on the waiting list was KONOS status 1 (highest priority) in 3.8%, status 2A in 3.9%, status 2B in 41.9%, status 3 to 7 (lowest priority) in 50.5%. Their median survival periods were 1, 1, 18, and 59 months, respectively. The mean Child-Pugh score was 8.5 ± 2.5 and Model for End-stage Liver Disease (MELD) score 18.1 ± 9.8.

CONCLUSIONS

Patients with high MELD scores or hepatocellular carcinoma succumbed soon after being entered on to the waiting list. By increasing organ donation rates and developing a risk-based allocation system, it should be possible to reduce mortality among patients on organ waiting lists.