3D auto-segmentation of biliary structure of living liver donors using magnetic resonance cholangiopancreatography for enhanced preoperative planning.

BACKGROUND: This study aimed to develop an automated segmentation system for biliary structures using a deep learning model, based on data from magnetic resonance cholangiopancreatography (MRCP). MATERIALS AND METHODS: Living liver donors who underwent MRCP using the gradient and spin echo technique followed by three-dimensional modeling were eligible for this study. A three-dimensional residual U-Net model was implemented for the deep learning process. Data were divided into training and test sets at a 9:1 ratio. Performance was assessed using the dice similarity coefficient to compare the model's segmentation with the manually labeled ground truth. RESULTS: The study incorporated 250 cases. There was no difference in the baseline characteristics between the train set (n=225) and test set (n=25). The overall mean Dice Similarity Coefficient was 0.80±0.20 between the ground truth and inference result. The qualitative assessment of the model showed relatively high accuracy especially for the common bile duct (88%), common hepatic duct (92%), hilum (96%), right hepatic duct (100%), and left hepatic duct (96%), while the third-order branch of the right hepatic duct (18.2%) showed low accuracy. CONCLUSION: The developed automated segmentation model for biliary structures, utilizing MRCP data and deep learning techniques, demonstrated robust performance and holds potential for further advancements in automation.

Biliary complications after adult-to-adult living-donor liver transplantation: An international multicenter study of 3633 cases.

In living-donor liver transplantation, biliary complications including bile leaks and biliary anastomotic strictures remain significant challenges, with incidences varying across different centers. This multicentric retrospective study (2016-2020) included 3633 adult patients from 18 centers and aimed to identify risk factors for these biliary complications and their impact on patient survival. Incidences of bile leaks and biliary strictures were 11.4% and 20.6%, respectively. Key risk factors for bile leaks included multiple bile duct anastomoses (odds ratio, [OR] 1.8), Roux-en-Y hepaticojejunostomy (OR, 1.4), and a history of major abdominal surgery (OR, 1.4). For biliary anastomotic strictures, risk factors were ABO incompatibility (OR, 1.4), blood loss >1 L (OR, 1.4), and previous abdominal surgery (OR, 1.7). Patients experiencing biliary complications had extended hospital stays, increased incidence of major complications, and higher comprehensive complication index scores. The impact on graft survival became evident after accounting for immortal time bias using time-dependent covariate survival analysis. Bile leaks and biliary anastomotic strictures were associated with adjusted hazard ratios of 1.7 and 1.8 for graft survival, respectively. The study underscores the importance of minimizing these risks through careful donor selection and preoperative planning, as biliary complications significantly affect graft survival, despite the availability of effective treatments.

Laparoscopic liver resection as a treatment option for intrahepatic cholangiocarcinoma.

Laparoscopic liver resection (LLR) remains controversial in the treatment of intrahepatic cholangiocarcinoma (ICC). The aim of the present study is to investigate the outcomes of LLR for ICC compared to open liver resection (OLR). We retrospectively reviewed patients who underwent surgery for ICC between January 2013 and February 2020. OLR and LLR were compared after propensity score matching (PSM). Overall survival (OS) and recurrence-free survival (RFS) were compared between the matched groups. During the study period, 219 patients met the inclusion criteria (OLR = 170 patients, 77.6%; LLR = 49 patients, 22.4%). Two groups of 43 patients each were analyzed after PSM. The 5-year RFS and OS were 44.6% and 47.9% in the OLR group and 50.9% and 39.8% in the LLR group, respectively. Hospital stay and intensive care unit care were significantly shorter and lower in the LLR group than in the OLR group, respectively. Total postoperative complications and complication rates for those Clavien-Dindo grade 3 or higher were similar between the OLR group and the LLR group. Multiple tumors and lymph node metastases were predisposing factors for tumor recurrence and death in multivariate analysis. The present study suggests that LLR should be considered in selective ICC because of short hospitalization and similar oncologic outcome and overall survival.

Safety and efficacy of early corticosteroid withdrawal in liver transplant recipients: A randomized controlled trial.

Backgrounds/Aims: Prolonged use of steroids after liver transplantation (LT) significantly increases the risk of diabetes or cardiovascular disease, which can adversely affect patient outcomes. Our study evaluated the effectiveness and safety of early steroid withdrawal within the first year following LT. Methods: This study was conducted as an open-label, multicenter, randomized controlled trial. Liver transplant recipients were randomly assigned to one of the following two groups: Group 1, in which steroids were withdrawn two weeks posttransplantation, and Group 2, in which steroids were withdrawn three months posttransplantation. This study included participants aged 20 to 70 years who were scheduled to undergo a single-organ liver transplant from a living or deceased donor at one of the four participating centers. Results: Between November 2012 and August 2020, 115 patients were selected and randomized into two groups, with 60 in Group 1 and 55 in Group 2. The incidence of new-onset diabetes after transplantation (NODAT) was notably higher in Group 1 (32.4%) than in Group 2 (10.0%) in the per-protocol set. Although biopsy-proven acute rejection, graft failure, and mortality did not occur, the median tacrolimus trough level/dose/weight in Group 1 exceeded that in Group 2. No significant differences in safety parameters, such as infection and recurrence of hepatocellular carcinoma, were observed between the two groups. Conclusions: The present study did not find a significant reduction in the incidence of NODAT in the early steroid withdrawal group. Our study suggests that steroid withdrawal three months posttransplantation is a standard and safe immunosuppressive strategy for LT patients.

Liver resection in selective hepatocellular carcinoma with Vp3 or Vp4 portal vein tumor thrombosis improves prognosis.

BACKGROUND/AIM: Hepatocellular carcinoma (HCC) tumor thrombi located in the first branch of the portal vein (Vp3) or in the main portal trunk (Vp4) are associated with poor prognosis. This study aimed to investigate the clinicopathological characteristics and risk factors for HCC recurrence and mortality following liver resection (LR) in patients with Vp3 or Vp4 HCC. METHODS: The study included 64 patients who underwent LR for HCC with Vp3 or Vp4 portal vein tumor thrombosis (PVTT). RESULTS: Fifty-eight patients (90.6%) had Vp3 PVTT, whereas the remaining six patients exhibited Vp4 PVTT. The median tumor size measured 8 cm, with approximately 36% of patients presented with multiple tumors. Fifty-four patients (84.4%) underwent open LR, whereas 10 patients underwent laparoscopic LR. In the Vp4 cases, combined LR and tumor thrombectomy were performed. The 3-year cumulative disease-free survival rate was 42.8% for the Vp3 group and 22.2% for the Vp4 group. The overall survival (OS) rate at 3 years was 47.9% for the Vp3 group and 60.0% for the Vp4 group. Intrahepatic metastasis has been identified as an important contributor to HCC recurrence. High hemoglobin levels are associated with high mortality. CONCLUSION: LR is a safe and effective treatment modality for selected patients with Vp3 or Vp4 HCC PVTT. This suggests that LR is a viable option for these patients, with favorable outcomes in terms of OS.

Impact of virtual reality education on disease-specific knowledge and anxiety for hepatocellular carcinoma patient scheduled for liver resection: a randomized controlled study.

PURPOSE: Hepatocellular carcinoma (HCC) is a significant health concern, and the complexity of liver anatomy poses challenges in conveying radiologic findings and surgical plans to patients. This study aimed to evaluate the impact of a virtual reality (VR) education program on anxiety and knowledge in HCC patients undergoing hepatic resection. METHOD: From 1 January 2022 to 28 February 2023, 88 patients were enrolled in a randomized controlled trial, divided into the VR group ( n =44) and the control group ( n =44). The VR group received patient-specific 3D liver model education through a VR platform, while the control group underwent conventional explanation processes. Both groups completed preintervention and postintervention questionnaires assessing anxiety (using STAI-X-1, STAI-X-2, and VAS) and knowledge about liver resection. Comparison of the questionnaires were performed between the two groups. Multivariable logistic regression was performed to analyze factor related to decrease in anxiety. RESULT: While there was no significant difference in preintervention anxiety and knowledge scores between the two groups, the VR group exhibited significant reduction in STAI-X-1 scores (-4.14±7.5) compared to the control group (-0.84±5.7, P =0.023), as well as knowledge scores (17.20±2.6) compared to the control group (13.42±3.3, P <0.001). In the multivariable logistic regression model, VR education showed significant impact on decrease in STAI-X-1 score, postintervention. (OR=2.902, CI=1.097-7.674, P =0.032). CONCLUSION: The VR education program significantly improved knowledge and reduced anxiety among HCC patients compared to conventional methods. This study suggests that VR can be a valuable tool in patient education, enhancing comprehension and alleviating presurgical anxiety.

Recurrence-free Survival After Liver Transplantation Versus Surgical Resection for Hepatocellular Carcinoma: Role of High-risk MRI Features.

BACKGROUND: This study aimed to evaluate recurrence-free survival (RFS) and overall survival (OS) after liver transplantation (LT) or liver resection (LR) for hepatocellular carcinoma (HCC) and perform subgroup analysis for HCC with high-risk imaging findings for recurrence on preoperative liver magnetic resonance imaging (MRI; high-risk MRI features). METHODS: We included patients with HCC eligible for both LT and LR and received either of the treatments between June 2008 and February 2021 from 2 tertiary referral medical centers after propensity score-matching. RFS and OS were compared between LT and LR using Kaplan-Meier curves with the log-rank test. RESULTS: Propensity score-matching yielded 79 patients in the LT group and 142 patients in the LR group. High-risk MRI features were noted in 39 patients (49.4%) in the LT group and 98 (69.0%) in the LR group. The Kaplan-Meier curves for RFS and OS were not significantly different between the 2 treatments among the high-risk group (RFS, P = 0.079; OS, P = 0.755). Multivariable analysis showed that treatment type was not a prognostic factor for RFS and OS ( P = 0.074 and 0.937, respectively). CONCLUSIONS: The advantage of LT over LR for RFS may be less evident among patients with high-risk MRI features.

Preoperative assessment of microvascular invasion risk using gadoxetate-enhanced MRI for predicting outcomes after liver transplantation for single hepatocellular carcinoma within the Milan criteria.

OBJECTIVE: To compare therapeutic outcomes after liver transplantation (LT) between hepatocellular carcinomas (HCC) with low and high risk for microvascular invasion (MVI) within the Milan criteria evaluated preoperatively. METHODS: Eighty patients with a single HCC who underwent LT as the initial therapy between 2008 and 2017 were included from two tertiary referral medical centers in a HBV-predominant population. A preoperative MVI-risk model was used to identify low- and high-risk patients. Recurrence-free survival (RFS) after LT between the two risk groups was compared using Kaplan-Meier curves with the log-rank test. Prognostic factors for RFS were identified using a multivariable Cox hazard regression analysis. RESULTS: Eighty patients were included (mean age, 51.8 years +/- 7.5 [standard deviation], 65 men). Patients were divided into low-risk (n = 64) and high-risk (n = 16) groups for MVI. The RFS rates after LT were significantly lower in the MVI high-risk group compared to the low-risk group at 1 year (75.0% [95% CI: 56.5-99.5%] vs. 96.9% [92.7-100%], p = 0.048), 3 years (62.5% [42.8-91.4%] vs. 95.3% [90.3-100%], p = 0.008), and 5 years (62.5% [42.8-91.4%] vs. and 95.3% [90.3-100%], p = 0.008). In addition, multivariable analysis showed that MVI high risk was the only significant factor for poor RFS (p = 0.016). CONCLUSION: HCC patients with a high risk of MVI showed significantly lower RFS after LT than those without. This model could aid in selecting optimal candidates in addition to the Milan criteria when considering upfront LT for patients with HCC if alternative treatment options are available. CLINICAL RELEVANCE STATEMENT: High risk for microvascular invasion (MVI) in hepatocellular carcinoma patients lowered recurrence-free survival after liver transplantation, despite meeting the Milan criteria. Identifying MVI risk could aid candidate selection for upfront liver transplantation, particularly if alternative treatments are available. KEY POINTS: • A predictive model-derived microvascular invasion (MVI) high- and low-risk groups had a significant difference in the incidence of MVI on pathology. • Recurrence-free survival after liver transplantation (LT) for single hepatocellular carcinoma (HCC) within the Milan criteria was significantly different between the MVI high- and low-risk groups. • The peak incidence of tumor recurrence was 20 months after liver transplantation, probably indicating that HCC with high risk for MVI had a high risk of early (≤ 2 years) tumor recurrence.

Upper thigh skeletal muscle index predicts outcomes in liver transplant recipients.

Purpose: The skeletal muscle index (SMI) at the L3 level is widely used to diagnose sarcopenia. The upper thigh (UT) also reflects changes in whole-body muscle mass, but no study has examined this using the UT to diagnose sarcopenia in liver transplantation (LT). This study aimed to determine an optimal cut-off value for UT-SMI and investigate how sarcopenia diagnosed by UT-SMI correlates with outcomes in LT recipients. Methods: In this retrospective study of 332 LT patients from 2018 to 2020, we investigated the association between sarcopenia diagnosed by UT-SMI and patient outcomes after LT. Results: The cut-off values for UT-SMI were 38.3 cm2/m2 for females (area under the curve [AUC], 0.927; P < 0.001) and 46.7 cm2/m2 for males (AUC, 0.898; P < 0.001). The prevalence of sarcopenia diagnosed by UT-SMI was 33.4% in our cohort. Patient and graft survival rates in the UT-SMI sarcopenia group were significantly poorer than those in the UT-SMI non-sarcopenia group (P < 0.001 and P < 0.001). UT-SMI was an independent prognostic factor for patient survival (hazard ratio [HR], 2.182; 95% confidence interval [CI], 1.183-4.025; P = 0.012) and graft survival (HR, 2.227; 95% CI, 1.054-4704; P = 0.036) in our multivariable Cox analysis. Conclusion: We confirmed that sarcopenia diagnosed by UT-SMI is associated with outcomes in LT recipients. In addition, UT-SMI was identified as an independent prognostic factor for patient survival and graft survival. Therefore, UT-SMI could be a good option for CT-based evaluations of sarcopenia in LT recipients.

Benefit of living donor liver transplantation in graft survival for extremely high model for end-stage liver disease score ≥35.

BACKGROUND AND AIMS: Living liver donation with high model for end-stage liver disease (MELD) score was discouraged despite organ shortage. This study aimed to compare graft survival between living donor liver transplantation (LDLT) and deceased donor liver transplantation (DDLT) recipients with extremely high-MELD (score of ≥35). METHODS: Between 2008 and 2018, 359 patients who underwent liver transplantation with a MELD score ≥35 were enrolled. We compared graft survival between LDLT and DDLT after propensity score matching (PSM) and performed subgroup analysis according to donor type. RESULTS: After PSM, there was no statistical difference in graft survival between the LDLT and DDLT groups (p = .466). Old age, acute on chronic liver failure, re-transplantation, preoperative intensive care unit stay and red blood cell (RBC) transfusion during the operation were risk factors for graft failure (p = .046, .005, .032, .015 and .001, respectively). Biliary complications were more common in the LDLT group (p = .021), while viral infection, postoperative uncontrolled ascites, and postoperative hemodialysis were more common in the DDLT group (p = .002, .018, and .027, respectively). In the LDLT group, acute chronic liver failure, intraoperative RBC transfusion, and early postoperative complications were risk factors for graft failure (p = .007, <.001, and .001, respectively). CONCLUSION: Our study showed that LDLT is not inferior to DDLT in graft survival if appropriate risk evaluation is performed in cases of extremely high-MELD scores. This result will help overcome organ shortages in high-MELD liver transplantation.

Automated 3D liver segmentation from hepatobiliary phase MRI for enhanced preoperative planning.

Recent advancements in deep learning have facilitated significant progress in medical image analysis. However, there is lack of studies specifically addressing the needs of surgeons in terms of practicality and precision for surgical planning. Accurate understanding of anatomical structures, such as the liver and its intrahepatic structures, is crucial for preoperative planning from a surgeon's standpoint. This study proposes a deep learning model for automatic segmentation of liver parenchyma, vascular and biliary structures, and tumor mass in hepatobiliary phase liver MRI to improve preoperative planning and enhance patient outcomes. A total of 120 adult patients who underwent liver resection due to hepatic mass and had preoperative gadoxetic acid-enhanced MRI were included in the study. A 3D residual U-Net model was developed for automatic segmentation of liver parenchyma, tumor mass, hepatic vein (HV), portal vein (PV), and bile duct (BD). The model's performance was assessed using Dice similarity coefficient (DSC) by comparing the results with manually delineated structures. The model achieved high accuracy in segmenting liver parenchyma (DSC 0.92 ± 0.03), tumor mass (DSC 0.77 ± 0.21), hepatic vein (DSC 0.70 ± 0.05), portal vein (DSC 0.61 ± 0.03), and bile duct (DSC 0.58 ± 0.15). The study demonstrated the potential of the 3D residual U-Net model to provide a comprehensive understanding of liver anatomy and tumors for preoperative planning, potentially leading to improved surgical outcomes and increased patient safety.

Long-Term Outcomes of Liver Transplantation in Hepatocellular Carcinoma with Bile Duct Tumor Thrombus: A Comparison with Portal Vein Tumor Thrombus.

Liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) remains controversial. This study analyzed the recurrence and overall survival rates through long-term results after LT in HCC patients with BDTT and compared the results after LT in HCC patients with portal vein tumor thrombus (PVTT). We performed a retrospective study of 45 patients with PVTT, 16 patients with BDTT, and 11 patients with coexisting PVTT and BDTT among HCC patients who underwent LT at a single center from 1999 to 2020. The HCC recurrence rates were 40.4% at 1 year, 30.3.3% at 2 years, and 27.6% at 3 years in the PVTT group; 66.7%, 53.3%, and 46.7% in the BDTT group; and 22.2%, 22.2%, and 0% in the coexisting group (p = 0.183). Overall patient survival rates were 68.4% at 1 year, 54.3% at 2 years, and 41.7% at 3 years in the PVTT group; 81.3%, 62.5%, and 48.2% in the BDTT group; and 63.6%, 27.3%, and 0% in the coexisting group (p = 0.157). In the multivariate analysis, the pre-transplantation model for tumor recurrence after liver transplantation (MoRAL) score and model for end-stage liver disease (MELD) score were found to be independent risk factors for recurrence and survival in all groups. HCC patients with BDTT showed no difference in recurrence and survival compared with HCC patients with PVTT at the long-term follow-up after LT.

Ventilator support in the pretransplant period predisposes early graft failure after deceased donor liver transplantation.

Purpose: Deceased donor liver transplantation (DDLT) recipients in Korea are generally sicker due to an increasing organ shortage. In the present study, the risk factors for early 30-day liver graft failure after DDLT were identified. Methods: From August 2017 to February 2021, 265 adult DDLTs were performed. The characteristics of patients with and without 30-day graft failure were compared. Results: Liver graft failure occurred in 11 patients (17.7%) after DDLT. Baseline and perioperative characteristics of donors and recipients were not statistically significantly different between the 2 groups. The cumulative graft and overall survival rates at 6 months were 83.9% and 88.7%, respectively. Multivariate analysis showed ventilator support in the pretransplant period was a predisposing factor for 30-day graft failure after DDLT. Conclusion: Present study indicates that cautious decision is required when allocating DDLT in critically ill patients on mechanical ventilatory support.

Abrogation of greater graft failure risk of female-to-male liver transplantation with donors older than 40 years or graft macrosteatosis greater than 5.

Greater graft-failure-risk of female-to-male liver transplantation (LT) is thought to be due to acute decrease in hepatic-estrogen-signaling. Our previous research found evidence that female hepatic-estrogen-signaling decreases after 40 years or with macrosteatosis. Thus, we hypothesized that inferiority of female-to-male LT changes according to donor-age and macrosteatosis. We stratified 780 recipients of grafts from living-donors into four subgroups by donor-age and macrosteatosis and compared graft-failure-risk between female-to-male LT and other LTs within each subgroup using Cox model. In recipients with ≤ 40 years non-macrosteatotic donors, graft-failure-risk was significantly greater in female-to-male LT than others (HR 2.03 [1.18-3.49], P = 0.011). Within the subgroup of recipients without hepatocellular carcinoma, the inferiority of female-to-male LT became greater (HR 4.75 [2.02-11.21], P < 0.001). Despite good graft quality, 1y-graft-failure-probability was 37.9% (23.1%-57.9%) in female-to-male LT within this subgroup while such exceptionally high probability was not shown in any other subgroups even with worse graft quality. When donor was > 40 years or macrosteatotic, graft-failure-risk was not significantly different between female-to-male LT and others (P > 0.60). These results were in agreement with the estrogen receptor immunohistochemistry evaluation of donor liver. In conclusion, we found that the inferiority of female-to-male LT was only found when donor was ≤ 40 years and non-macrosteatotic. Abrogation of the inferiority when donor was > 40 years or macrosteatotic suggests the presence of dominant contributors for post-transplant graft-failure other than graft quality/quantity and supports the role of hepatic-estrogen-signaling mismatch on graft-failure after female-to-male LT.

Graft-recipient-weight ratio and lowered immunosuppression is important for the success of adult liver retransplantation.

This study analyzed the risk of liver retransplantation and factors related to better outcome. Adult liver transplantations performed during 1996-2021 were included. Comparison between first transplantation and retransplantation were performed. Among retransplantation cases, comparison between whole liver and partial liver graft was performed. Multivariable Cox analyses for analyzing risk factors for primary graft and overall patient survival were performed for the entire cohort as well as the subgroup of patients with retransplantation. A total 2237 transplantations from 2135 adults were included and 103 cases were retransplantation. A total of 44 cases (42.7%) were related to acute graft dysfunction while 59 cases (57.3%) were related to subacute or chronic graft dysfunction. Retransplantation was related poor primary graft (HR 3.439, CI 2.230-5.304, P < 0.001) and overall patient survival. (HR 2.905, CI 2.089-4.040, P < 0.001) Among retransplantations, mean serum FK506 trough level ≥ 9 ng/mL was related to poor primary graft (HR 3.692, CI 1.288-10.587, P = 0.015) and overall patient survival. (HR 2.935, CI 1.195-7.211, P = 0.019) Graft-recipient-weight ratio under 1.0% was related to poor overall patient survival in retransplantations. (HR 3.668, CI 1.150-11.698, P = 0.028). Retransplantation can be complicated with poor graft and patient survival compared to first transplantation, especially when the graft size is relatively small. Lowering the FK506 trough level during the first month can be beneficial for outcome.

Novel Benchmark for Adult-to-Adult Living-donor Liver Transplantation: Integrating Eastern and Western Experiences.

OBJECTIVE: To define benchmark values for adult-to-adult living-donor liver transplantation (LDLT). BACKGROUND: LDLT utilizes living-donor hemiliver grafts to expand the donor pool and reduce waitlist mortality. Although references have been established for donor hepatectomy, no such information exists for recipients to enable conclusive quality and comparative assessments. METHODS: Patients undergoing LDLT were analyzed in 15 high-volume centers (≥10 cases/year) from 3 continents over 5 years (2016-2020), with a minimum follow-up of 1 year. Benchmark criteria included a Model for End-stage Liver Disease ≤20, no portal vein thrombosis, no previous major abdominal surgery, no renal replacement therapy, no acute liver failure, and no intensive care unit admission. Benchmark cutoffs were derived from the 75th percentile of all centers' medians. RESULTS: Of 3636 patients, 1864 (51%) qualified as benchmark cases. Benchmark cutoffs, including posttransplant dialysis (≤4%), primary nonfunction (≤0.9%), nonanastomotic strictures (≤0.2%), graft loss (≤7.7%), and redo-liver transplantation (LT) (≤3.6%), at 1-year were below the deceased donor LT benchmarks. Bile leak (≤12.4%), hepatic artery thrombosis (≤5.1%), and Comprehensive Complication Index (CCI ® ) (≤56) were above the deceased donor LT benchmarks, whereas mortality (≤9.1%) was comparable. The right hemiliver graft, compared with the left, was associated with a lower CCI ® score (34 vs 21, P < 0.001). Preservation of the middle hepatic vein with the right hemiliver graft had no impact neither on the recipient nor on the donor outcome. Asian centers outperformed other centers with CCI ® score (21 vs 47, P < 0.001), graft loss (3.0% vs 6.5%, P = 0.002), and redo-LT rates (1.0% vs 2.5%, P = 0.029). In contrast, non-benchmark low-volume centers displayed inferior outcomes, such as bile leak (15.2%), hepatic artery thrombosis (15.2%), or redo-LT (6.5%). CONCLUSIONS: Benchmark LDLT offers a valuable alternative to reduce waitlist mortality. Exchange of expertise, public awareness, and centralization policy are, however, mandatory to achieve benchmark outcomes worldwide.

Safety and Efficacy of Conversion to Once-Daily Tacrolimus from Twice-Daily Tacrolimus in Pediatric Liver Transplant Recipients.

BACKGROUND: Nonadherence to immunosuppression is the most common cause of late acute rejection in pediatric liver transplant (LT) recipients. A prolonged-release once-daily tacrolimus formulation was developed to improve adherence and long-term allograft survival. METHODS: We screened 179 pediatric LT recipients who converted from twice-daily tacrolimus (TD-TAC) to once-daily tacrolimus (OD-TAC) between February 2011 and September 2019. RESULTS: One hundred seventy-nine recipients converted to OD-TAC and were followed for 18 months. 152 OD-TAC-converted recipients (84.9%) experienced uneventful follow-up, while 21 recipients showed LFT elevation. Four recipients had biopsy-proven acute rejection within six months of conversion, all of which were successfully treated with steroid pulse. 166 recipients (92.7%) remain on OD-TAC and 13 (7.3%) were switched back to TD-TAC. The mean tacrolimus trough level significantly decreased three months following conversion (3.14 ± 1.9 ng/mL) compared with pre-conversion levels (3.69 ± 1.98 ng/mL). Mean tacrolimus trough levels remained unchanged from 3 months to 12 months following conversion. Percent coefficient of variation of tacrolimus trough levels decreased significantly from 32.5 ± 16.4 ng/mL to 27.5 ± 15.6 ng/mL after conversion to OD-TAC, reflecting a decrease in variation of tacrolimus trough levels following conversion. CONCLUSIONS: Conversion to OD-TAC in pediatric LT recipients with stable graft function is safe and effective. LEVEL OF EVIDENCE: Level IV.

Hepatic venous territory mapping in living donor liver transplantation using right liver graft: an objective parameter for venous reconstruction.

Purpose: This study evaluated the clinical implication of hepatic venous territory mapping in living donor liver transplantation. Methods: Living donor liver transplantations performed using right graft since 2017 were included. Hepatic venous volume mapping was started in 2019. Risk factors for graft failure and overall survival were analyzed. Analysis for factors related to occlusion of reconstructed vein was performed. Results: Among 445 patients included, 213 underwent hepatic venous mapping. Hepatic venous mapping itself was not a significant factor for graft (hazard ratio [HR], 0.958; 95% confidence interval [CI], 0.441-2.082; P = 0.913) and overall survival (HR, 0.627; 95% CI, 0.315-1.247; P = 0.183). Inferior hepatic vein occlusion was a significant risk factor for both graft survival (HR, 8.795; 95% CI, 1.628-47.523; P = 0.012) and overall survival (HR, 11.13; 95% CI, 2.460-50.300; P = 0.002). In a subgroup with middle hepatic vein reconstruction, occlusion was a significant risk factor for overall survival (HR, 3.289; 95% CI, 1.304-8.296; P = 0.012). In patients with middle hepatic vein reconstruction whose venous territory volumes were measured, right anterior volume of ≥300 cm3 was protective for vein occlusion (OR, 0.317; 95% CI, 0.152-0.662; P = 0.002). In patients with V5 reconstruction, V5 volume of ≥150 cm3 was protective for vein occlusion (OR, 0.253; 95% CI, 0.087-0.734; P = 0.011). Conclusion: Inferior and middle hepatic vein reconstruction has significant impact on clinical outcome. Hepatic venous territory mapping can provide an objective measure for successful reconstruction of venous branches.