Development and validation of MRI PDFF Cut-offs for living liver donor eligibility assessment.

Hepatic steatosis (HS) criteria for living donor liver transplantation (LDLT) donor eligibility should be based on large droplet fat as per Banff consensus recommendations. We aimed to establish MRI PDFF cut-offs for HS assessment in potential LDLT donors. This retrospective study included consecutive potential LDLT donors who underwent MRI and liver biopsy between 2013 and 2023 at two tertiary institutions, each as development (n=3062; 2015 men; median [interquartile range] age of 32 [25-38] years) and external validation (n=472; 287 men; 35 [26-44] years) datasets. PDFF was measured using dedicated MRI sequences. Histologic HS defined as large droplet fat fraction was used as the reference standard. Dual PDFF cut-offs aimed at 95% sensitivity or 95% specificity, for diagnosing histologic HS of ≥10%, ≥20%, ≥30%, and ≥40%, were determined in the development dataset using ten-fold cross validation. The cut-offs were then validated in the external validation dataset. Equation for estimating histologic HS from PDFF was also derived using linear regression. The PDFF cut-offs for histologic HS of ≥10%, ≥20%, ≥30%, and ≥40%, targeting 95% sensitivity, were 3.7%, 5.5%, 8.0%, and 10.0%, respectively. External validation demonstrated high sensitivities ≥ 97.9% with specificities ranging from 60.9% to 95.1%. The PDFF cut-offs targeting 95% specificity were 6.3%, 8.0%, 9.1%, and 10.1%, respectively. External validation rendered high specificities ranging from 88.5% to 95.3% with sensitivities ranging from 76.6% to 100%. For diagnosing histologic HS ≥30%, which is the most prevalently used threshold for LDLT donor eligibility assessment, the PDFF cut-offs achieved sensitivities and specificities of both over 90%. The equation of (Histologic HS=-2.95 + 1.93 * PDFF) was derived.

Reconstruction of all hepatic arteries in right lobe grafts with 2 hepatic arteries and zero percent hepatic artery thrombosis.

Hepatic artery thrombosis (HAT) is a common cause of graft loss in living-donor liver transplantation, occurring in ~2.5%-8% of patients. Some right lobe grafts have 2 hepatic arteries (HAs), and the optimal reconstruction technique remains controversial. This study aimed to identify risk factors for HAT and to evaluate the efficacy of reconstructing 2 HAs in right lobe grafts. This retrospective, single-center study analyzed 1601 living-donor liver transplantation recipients with a right liver graft and divided them into 1 HA (n = 1524) and 2 HA (n = 77) groups. The reconstruction of all HAs was performed using a microscope with an interrupted suture. The primary outcome was any HAT event. Of the 1601 patients, 37.8% had a history of transcatheter arterial chemoembolization, and 130 underwent pretransplant hepatectomy. Extra-anatomical arterial reconstruction was performed in 38 cases (2.4%). HAT occurred in 1.2% of patients (20/1601) who underwent surgical revascularization. In the multivariate analysis, undergoing pretransplant hepatectomy ( p = 0.008), having a female donor ( p = 0.02), having a smaller graft-to-recipient weight ratio ( p = 0.002), and undergoing extra-anatomical reconstruction ( p = 0.001) were identified as risk factors for HAT. However, having 2 HA openings in right liver grafts was not a risk factor for HAT in our series. Kaplan-Meier survival analysis showed no significant difference in graft survival and patient survival rates between the 1 HA and 2 HA groups ( p = 0.09, p = 0.97). In our series, although the smaller HA in the 2 HA group should increase the risk of HAT, HAT did not occur in this group. Therefore, reconstructing both HAs when possible may be a reasonable approach in living-donor liver transplantation using a right liver graft with 2 HA openings.

Recipient blood group does not affect hepatocellular carcinoma recurrence after living donor liver transplantation in Korea.

PURPOSE: This study assessed whether or not the ABO blood type affects the incidence of HCC recurrence after living donor liver transplantation (LDLT). METHODS: This retrospective observational study included 856 patients with hepatocellular carcinoma (HCC) who underwent LDLT between January 2006 and December 2016 at the Asan Medical Center. RESULTS: This study included 324 patients (37.9%) with blood type A, 215 (25.1%) with blood type B, 210 (24.5%) with blood type O, and 107 (12.5%) with blood type AB. ABO-incompatible LT was performed in 136 (15.9%) patients. The independent risk factors for the disease-free survival (DFS) were maximal tumor diameter, microvascular invasion, and Milan criteria. The only independent risk factor for the overall survival (OS) was microvascular invasion. The ABO blood group did not affect the DFS (P = 0.978) or OS (P = 0.261). The DFS according to the ABO blood group did not differ significantly between the ABO-compatible (p = 0.701) and ABO-incompatible LDLT recipients (p = 0.147). The DFS according to the ABO blood group did not differ significantly between patients within the Milan criteria (p = 0.934) and beyond the Milan criteria (p = 0.525). The DFS did not differ significantly between recipients with and without type A blood (p = 0.941). CONCLUSIONS: This study demonstrated that the ABO blood group system had no prognostic impact on the oncological outcomes of patients undergoing LT for HCC.

Outcomes of 6000 living donor liver transplantation procedures: a pioneering experience at ASAN Medical Center.

Living donor liver transplantation (LDLT) has emerged as a favorable alternative to deceased donor liver transplantation, significantly reducing waitlist mortality, particularly in Asian countries with very low deceased organ donation rates. Asan Medical Center (AMC) in South Korea has pioneered innovative LDLT surgical techniques and become established as an extremely high-volume center for LDLT. This retrospective study analyzed 6000 consecutive LDLT procedures, including 510 dual-graft procedures, performed at AMC between December 1994 and January 2021. Of these, 312 LDLT procedures were performed in children aged < 18 years. In adult recipients, liver cirrhosis (LC) related to viral hepatitis was the most common indication, occurring in 69.8% of cases. Biliary atresia (46.8%) was the most common indication for pediatric LDLT. This study demonstrated outstanding long-term outcomes, with patient survival rates at 1, 5, 10, and 20 years of 92.7%, 85.9%, 82.1%, and 70.9%, respectively, in LDLT group for adults aged 50 and under at the time of LDLT, and 92.9%, 89.0%, 88.1%, and 81.9%, respectively, in the pediatric group. The in-hospital mortality rate of adult recipients was 3.8% (n = 214/5688). This study demonstrates the importance of refined surgical techniques, selection of grafts tailored to the recipient, and comprehensive multidisciplinary perioperative patient care in expanding the scope of LDLT and improving recipient outcomes.

Safety of right liver donation after improving steatosis through weight loss in living donors: a retrospective study.

BACKGROUND: Living donor liver transplantation using hepatic steatosis-improved grafts mitigates donor shortage. Herein, we aimed to evaluate the safety and feasibility of right-lobe adult-to-adult living donor liver transplantation using grafts improved through donor weight loss. METHODS: In this retrospective study conducted in a single institution in the Republic of Korea, we reviewed the medical records of living liver donors who lost ≥ 10% of their body weight to improve steatosis before right lobe donation between January 2015 and December 2020. Overall, 1040 right-lobe donors were included, with 150 and 890 donors in the weight loss and control (non-steatosis) groups, respectively. RESULTS: We performed 1:1 individual matching using the greedy matching method, by which 124 patients were included in each group. The median period from the date of the first visit to donation was 113 (interquartile range: 78-184) days in the weight loss group. As body weight changed from 82.8 ± 13.7 kg to 70.8 ± 11.8 kg (p < 0.0001), body mass index also improved from 27.8 ± 3.9 kg/m2 to 23.8 ± 3.1 kg/m2 (p < 0.0001). No significant between-group differences existed in the postoperative laboratory data for living donors and recipients. The incidence of postoperative complications in donors was comparable between the groups (control group, 9.7%; weight loss group, 13.7%; p = 0.3185). The graft and recipient survival rates were comparable between the groups (p = 1.000). CONCLUSION: Weight loss through diet and exercise significantly could improve hepatic steatosis in living donor candidates for liver transplantation, with the surgical outcomes in recipients and donors being equivalent to those in recipients and non-steatotic donors.

No Prognostic Impact of Graft-to-Recipient Weight Ratio on Hepatocellular Carcinoma Recurrence Following Living Donor Liver Transplantation.

BACKGROUND The effects of a low graft-to-recipient weight ratio (GRWR) on the prognosis of patients with hepatocellular carcinoma (HCC) are unclear. The present study examined whether the GRWR had an impact on the rate of HCC recurrence following living donor liver transplantation (LDLT). MATERIAL AND METHODS This retrospective observational single-center study included 856 patients who underwent LDLT for HCC between January 2006 and December 2016 at Asan Medical Center and evaluated the association between GRWR and post-transplant tumor recurrence. RESULTS Of the 856 patients who underwent LDLT for HCC, 54 (6.3%), 272 (31.8%), 274 (32.0%), and 256 (29.9%) had GRWR <0.8%, 0.8-0.99%, 1.0-1.19%, and ≥1.2%, respectively. Analysis of all patients revealed that the disease-free survival (DFS; P=0.545) and overall survival (OS; P=0.313) rates were not different in these 4 groups. Subgroups analyses also showed that GRWR did not influence survival rates in patients within (DFS: P=0.398; OS: P=0.676) and beyond (DFS: P=0.602; OS: P=0.649) the Milan criteria, or in patients with alpha-fetoprotein-des-γ-carboxyprothrombin-tumor volume scores <5log (DFS: P=0.633; OS: p=0.285) and ≥5log (DFS: P=0.674; OS: P=0.906). CONCLUSIONS GRWR less than 0.8% did not demonstrate a noteworthy prognostic influence on the oncological results among patients who had undergone LDLT for HCC. High-volume multi-center studies are necessary to validate these findings.

Achieving 400 Living Donor Liver Transplantations Annually During the COVID-19 Pandemic: A Single-Center Experience.

BACKGROUND: The COVID-19 pandemic has had a major impact on liver transplantation (LT) and living donor programs globally. PURPOSE: In this study, we aimed to present the principles and strategies of our LT program during the pandemic period and describe its achievements. BASIC PROCEDURES: We retrospectively reviewed the outcomes of 1417 LTs performed at Asan Medical Center, Seoul, Korea, from 2020 to 2022. Of these, 216 recipients who received transplants from deceased donors were excluded, and 1201 recipients who received transplants from 1268 live donors were included in the study, including 38 children <18 years old. MAIN FINDINGS: Among the 1201 living donor LT (LDLT) recipients, the most common indication for LT was unresectable hepatocellular carcinoma (315/1163, 27.1%) in adults and biliary atresia (29/38, 76.3%) in pediatric recipients. Emergency LDLT was performed in 40 patients (3.3%). The median model of end-stage liver disease and pediatric end-stage liver disease scores were 13.9 ± 7.2 and 13.8 ± 7.1, respectively. In-hospital mortality of recipients was higher than usual at 2.2%, but the cause of death was not related to COVID-19 infection. Of the 1268 live donors who underwent hepatectomy for liver donation, 660 (52.1%) underwent hepatectomy using a minimally invasive approach. Although 17 (1.3%) live donors experienced major complications, there were no serious life-threatening complications and no mortality. CONCLUSION: Even in a pandemic era, a team with well-established infection control protocols, patient-tailored surgical strategies, and thorough perioperative care can maintain LDLT at a similar quantitative and qualitative level as in a non-pandemic era.