Current Status of Living Donor Liver Transplantation: Impact, Advantages, and Challenges

Mortality and associated factors among patients who underwent liver transplantation in South Korea from 2017 to 2021: a retrospective observational study

Purpose

Liver transplantation (LT) in South Korea dates back to 1988. However, Asians may be reluctant to donate their organs because of the influence of their traditional religious and philosophical beliefs. We aimed to investigate the mortality and associated factors among patients admitted after LT in South Korea.

Methods

The South Korean National Health Insurance Service database was used as a data source. All adult patients who underwent LT between January 1, 2017 and December 31, 2021 (5 years) were included in the study.

Results

A total of 7,316 patients were included in the analysis (living donor LT [LDLT], 5,412; deceased donor LT [DDLT], 1,904). The 1-year mortality rate was 12.8% (LDLT, 8.2%; DDLT, 25.9%; P < 0.001), and the postoperative complication rate was 26.8% (LDLT, 16.7%; DDLT, 55.6%; P < 0.001). The average length of hospital stay was 30.8 days, and that in the intensive care unit was 6.1 days. The total mean cost was 69,954 US dollars, and the self-cost was 6,008 US dollars. After adjusting confounders, DDLT (hazard ratio [HR], 2.10; 95% confidence interval [CI], 1.79-5.20; P < 0.001), re-LDLT (HR, 4.82; 95% CI, 3.10-7.40; P < 0.001), re-DDLT (HR, 4.65; 95% CI, 3.55-7.12; P < 0.001), and postoperative complications (HR, 1.72; 95% CI, 1.39-2.12; P < 0.001) were potential risk factors for higher 1-year mortality after transplantation.

Conclusion

LDLT was performed at a higher rate in South Korea and was associated with lower mortality and fewer postoperative complications than DDLT. Redo LT led to higher mortality rates.

Exploring Anesthesiology Management of Living Donor Liver Transplantation: Survey From the Society for the Advancement of Transplant Anesthesia and the Korean Society for Transplantation Anesthesiologists

INTRODUCTION

While living donor liver transplantation (LDLT) serves as the predominant method of adult liver transplant (LT) in the Republic of Korea (ROK), it represents a minority of LT in the United States (US). A survey was conducted to gain insight into these nations' anesthetic management.

METHODS

An electronic questionnaire was distributed to directors of LT anesthesiology overseeing LDLT programs in both countries between May 2021 and October 2021.

RESULTS

The response rate was 93.0% (100% [37/37] in the US and 80% [16/20] in the ROK). Both countries mainly adhered to deceased donor LT recipient management practices, including the frequency of routine pulmonary artery catheter use, transesophageal echocardiography, and point-of-care coagulation monitoring. Differences were observed in early extubation of recipients (US vs. ROK: 39.7% vs. 14.7% of all cases), participation in donor selection meetings (88.9% [32/36] vs. 6.3% [1/16], p < 0.0001), application of the Enhanced Recovery After Surgery donor protocol (69.4% [25/36] vs. 12.5% [2/16], p < 0.0001), and cell saver usage for donors (94.4% [34/36] vs. 18.8% [3/16], p < 0.0001). More ROK programs implemented simultaneous donor/recipient anesthesia supervision by a single anesthesiologist.

CONCLUSIONS

Several important differences were identified between the US and the ROK in adult LDLT anesthetic management.

New insights into the regulation of bile acids synthesis during the early stages of liver regeneration: A human and experimental study

BACKGROUND AND AIMS

Liver regeneration is essential for the preservation of homeostasis and survival. Bile acids (BAs)-mediated signaling is necessary for liver regeneration, but BAs levels need to be carefully controlled to avoid hepatotoxicity. We studied the early response of the BAs-fibroblast growth factor 19 (FGF19) axis in healthy individuals undergoing hepatectomy for living donor liver transplant. We also evaluated BAs synthesis in mice upon partial hepatectomy (PH) and acute inflammation, focusing on the regulation of cytochrome-7A1 (CYP7A1), a key enzyme in BAs synthesis from cholesterol.

METHODS

Serum was obtained from twelve human liver donors. Mice underwent 2/3-PH or sham-operation. Acute inflammation was induced with bacterial lipopolysaccharide (LPS) in mice fed control or antoxidant-supplemented diets. BAs and 7α-hydroxy-4-cholesten-3-one (C4) levels were measured by HPLC-MS/MS; serum FGF19 by ELISA. Gene expression and protein levels were analyzed by RT-qPCR and western-blot.

RESULTS

Serum BAs levels increased after PH. In patients with more pronounced hypercholanemia, FGF19 concentrations transiently rose, while C4 levels (a readout of CYP7A1 activity) dropped 2 h post-resection in all cases. Serum BAs and C4 followed the same pattern in mice 1 h after PH, but C4 levels also dropped in sham-operated and LPS-treated animals, without marked changes in CYP7A1 protein levels. LPS-induced serum C4 decline was attenuated in mice fed an antioxidant-supplemented diet.

CONCLUSIONS

In human liver regeneration FGF19 upregulation may constitute a protective response from BAs excess during liver regeneration. Our findings suggest the existence of post-translational mechanisms regulating CYP7A1 activity, and therefore BAs synthesis, independent from CYP7A1/Cyp7a1 gene transcription.

Clinical Factors Affecting the Rate of Liver Regeneration in Living Donors after Right Hepatectomy

Sufficient liver regeneration after a right hepatectomy is important in living donors for preventing postoperative hepatic insufficiency; however, it differs for each living donor so we investigated the clinical factors affecting the rate of liver regeneration after hepatic resection. This retrospective case-control study investigated fifty-four living donors who underwent a right hepatectomy from July 2015 to March 2023. Patients were classified into 2 groups by the remnant/total volume ratio (RTVR): Group A (RTVR < 30%, n = 9) and Group B (RTVR ≥ 30%, n = 45). The peak postoperative level of total bilirubin was more elevated in Group A than in Group B (3.0 ± 1.1 mg/dL vs. 2.3 ± 0.8 mg/dL, p = 0.046); however, no patients had hepatic insufficiency or major complications. The rates of residual liver volume (RLV) growth at Postoperative Week 1 (89.1 ± 26.2% vs. 53.5 ± 23.7%, p < 0.001) were significantly greater in Group A, and its significant predictors were RTVR (β = -0.478, p < 0.001, variance inflation factor (VIF) = 1.188) and intraoperative blood loss (β = 0.247, p = 0.038, VIF = 1.182). In conclusion, as the RLV decreases, compensatory liver regeneration after hepatic resection becomes more prominent, resulting in comparable operative outcomes. Further studies are required to investigate the relationship between hematopoiesis and the rate of liver regeneration.

Liver Transplantation for Hepatocellular Carcinoma: A Narrative Review and A Glimpse into The Future

Liver transplantation (LT) is a highly effective treatment for carefully selected patients with hepatocellular carcinoma (HCC). In this review, we explored the development of LT selection criteria and organ allocation policies, comparing original data to underscore their historical progression into the intricate task of quantitatively estimating pre- and post-LT survivals. We emphasized the role of biomarkers such as serum alpha-fetoprotein, Des-gamma-carboxy-prothrombin, circulating tumor cells, and circulating tumor DNA in predicting patient outcomes. Additionally, we examined the transplant-associated survival benefits and the difficulties in accurately calculating these benefits. We also reviewed recent advancements in targeted therapy and checkpoint inhibitors for advanced, inoperable HCC and projected their integration into LT for HCC. We further discussed the growing use of living donor liver transplants in the United States and compared its outcomes with those of deceased donor liver transplants. Furthermore, we examined the progress in machine perfusion techniques, which have shown potential in improving patient outcomes and enlarging the donor pool. These advancements present opportunities to enhance LT patient survivals, refine selection criteria, establish new priority metrics, develop innovative bridging and downstaging strategies, and formulate redesigned LT strategies for HCC treatments.