Outcomes and Risk Factors for Liver Transplantation Using graft-to-Recipient Weight Ratio Less than 0.8 Graft from Living Donors: Multicentric Cohort Study.

OBJECTIVE: To compare graft survival after LDLT in patients receiving GRWR<0.8 versus GRWR≥0.8 grafts and identify risk factors for graft loss using GRWR<0.8 grafts. SUMMARY BACKGROUND DATA: Favorable outcomes after living donor liver transplantation (LDLT) using graft-to-recipient weight ratio (GRWR)<0.8 grafts were recently reported; however, these results have not been validated using multicenter data. METHODS: This multicentric cohort study included 3450 LDLT patients. Graft survival was compared between 1:3 propensity score-matched groups and evaluated using various Cox models in the entire population. Risk factors for graft loss with GRWR<0.8 versus GRWR≥0.8 grafts were explored within various subgroups using interaction analyses, and outcomes were stratified according to the number of risk factors. RESULTS: In total, 368 patients (10.7%) received GRWR<0.8 grafts (GRWR<0.8 group), whereas 3082 (89.3%) received GRWR≥0.8 grafts (GRWR≥0.8 group). The 5-y graft survival rate was significantly lower with GRWR<0.8 grafts than with GRWR≥0.8 grafts (85.2% vs. 90.1%, P=0.013). Adjusted hazard ratio (HR) for graft loss using GRWR<0.8 grafts in the entire population was 1.66 (95% confidence interval [CI] 1.17-2.35, P=0.004). Risk factors exhibiting significant interactions with GRWR<0.8 for graft survival were age ≥60 y, MELD score ≥15, and male donor. When ≥2 risk factors were present, GRWR<0.8 grafts showed higher risk of graft loss compared to GRWR≥0.8 graft in LDLT (HR 2.98, 95% CI 1.79-4.88, P<0.001). CONCLUSIONS: GRWR<0.8 graft showed inferior graft survival than controls (85.2% vs. 90.1%), especially when ≥2 risk factors for graft loss (among age ≥60 y, MELD score ≥15, or male donor) were present.

Entecavir versus tenofovir on the recurrence of hepatitis B-related HCC after liver transplantation: A multicenter observational study.

Considerable controversy exists regarding the superiority of tenofovir disoproxil fumarate (TDF) over entecavir (ETV) for reducing the risk of HCC. This study aimed to compare outcomes of ETV versus TDF after liver transplantation (LT) in patients with HBV-related HCC. We performed a multicenter observational study using data from the Korean Organ Transplantation Registry. A total of 845 patients who underwent LT for HBV-related HCC were divided into 2 groups according to oral nucleos(t)ide analogue used for HBV prophylaxis post-LT: ETV group (n = 393) and TDF group (n = 452). HCC recurrence and overall death were compared in naïve and propensity score (PS)-weighted populations, and the likelihood of these outcomes according to the use of ETV or TDF were analyzed with various Cox models. At 1, 3, and 5 years, the ETV and TDF groups had similar HCC recurrence-free survival (90.7%, 85.6%, and 84.1% vs. 90.9%, 84.6%, and 84.2%, respectively, p = 0.98) and overall survival (98.4%, 94.7%, and 93.5% vs. 99.3%, 95.8%, and 94.9%, respectively, p = 0.48). The propensity score-weighted population showed similar results. In Cox models involving covariates adjustment, propensity score-weighting, competing risk regression, and time-dependent covariates adjustment, both groups showed a similar risk of HCC recurrence and overall death. In subgroup analyses stratified according to HCC burden (Milan criteria, Up-to-7 criteria, French alpha-fetoprotein risk score), pretransplantation locoregional therapy, and salvage LT, neither ETV nor TDF was superior. In conclusion, ETV and TDF showed mutual noninferiority for HCC outcomes when used for HBV prophylaxis after LT.

Aberrantly Expressed MicroRNAs in Cancer-Associated Fibroblasts and Their Target Oncogenic Signatures in Hepatocellular Carcinoma.

Cancer-associated fibroblasts (CAFs) contribute to tumor progression, and microRNAs (miRs) play an important role in regulating the tumor-promoting properties of CAFs. The objectives of this study were to clarify the specific miR expression profile in CAFs of hepatocellular carcinoma (HCC) and identify its target gene signatures. Small-RNA-sequencing data were generated from nine pairs of CAFs and para-cancer fibroblasts isolated from human HCC and para-tumor tissues, respectively. Bioinformatic analyses were performed to identify the HCC-CAF-specific miR expression profile and the target gene signatures of the deregulated miRs in CAFs. Clinical and immunological implications of the target gene signatures were evaluated in The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA_LIHC) database using Cox regression and TIMER analysis. The expressions of hsa-miR-101-3p and hsa-miR-490-3p were significantly downregulated in HCC-CAFs. Their expression in HCC tissue gradually decreased as HCC stage progressed in the clinical staging analysis. Bioinformatic network analysis using miRWalks, miRDB, and miRTarBase databases pointed to TGFBR1 as a common target gene of hsa-miR-101-3p and hsa-miR-490-3p. TGFBR1 expression was negatively correlated with miR-101-3p and miR-490-3p expression in HCC tissues and was also decreased by ectopic miR-101-3p and miR-490-3p expression. HCC patients with TGFBR1 overexpression and downregulated hsa-miR-101-3p and hsa-miR-490-3p demonstrated a significantly poorer prognosis in TCGA_LIHC. TGFBR1 expression was positively correlated with the infiltration of myeloid-derived suppressor cells, regulatory T cells, and M2 macrophages in a TIMER analysis. In conclusion, hsa-miR-101-3p and hsa-miR-490-3p were substantially downregulated miRs in CAFs of HCC, and their common target gene was TGFBR1. The downregulation of hsa-miR-101-3p and hsa-miR-490-3p, as well as high TGFBR1 expression, was associated with poor clinical outcome in HCC patients. In addition, TGFBR1 expression was correlated with the infiltration of immunosuppressive immune cells.

Risk Factors for Beyond Milan Recurrence After Hepatic Resection for Single Hepatocellular Carcinoma No Larger Than 5 Centimeters.

Hepatic resection (HR) is considered a treatment of choice for a single hepatocellular carcinoma (HCC) ≤5 cm in patients with preserved liver function. However, it is possible for these patients to develop a severe form of recurrence (beyond Milan recurrence [BMR] criteria). This recurrence could have been avoided if liver transplantation (LT) was performed primarily, as LT is believed to yield a more favorable oncological outcome compared with HR. The aim of this study was to determine the risk factors for BMR after HR and to verify whether primary LT can provide a more favorable outcome in patients with BMR risk factors. Data from 493 patients who underwent HR for HCC ≤5 cm between 1995 and 2016 were analyzed. Among them, 74 patients (15%) experienced BMR. The 10-year survival rate of patients with BMR was significantly low compared with that of patients without BMR (22.6% versus 79.8%; P < 0.01). In multivariate analysis, calculated hepatic venous pressure gradient ≥7 mm Hg and microvascular invasion were identified as the risk factors for BMR (P < 0.05). During the same period, 63 eligible patients underwent LT as a primary treatment for HCC ≤5 cm. No significant difference in long-term survival rate was observed when no risk factor for BMR was present in the HR and LT groups (85.5% versus 100%; P = 0.39). However, 10-year survival was poorer in the HR group in the presence of risk factors for BMR (60.6% versus 91.8%; P < 0.001). Among the patients with HCCs ≤5 cm, which are resectable and transplantable, LT is indicated when calculated hepatic venous pressure gradient ≥7 mm Hg and/or microvascular invasion is present.

Surgical Outcomes of Hepatocellular Carcinoma With Bile Duct Tumor Thrombus: A Korea-Japan Multicenter Study.

OBJECTIVE: To identify optimal surgical methods and the risk factors for long-term survival in patients with hepatocellular carcinoma accompanied by macroscopic bile duct tumor thrombus (BDTT). SUMMARY BACKGROUND DATA: Prognoses of patients with hepatocellular carcinoma accompanied by BDTT have been known to be poor. There have been significant controversies regarding optimal surgical approaches and risk factors because of the low incidence and small number of cases in previous reports. METHODS: Records of 257 patients from 32 centers in Korea and Japan (1992-2014) were analyzed for overall survival and recurrence rate using the Cox proportional hazard model. RESULTS: Curative surgery was performed in 244 (94.9%) patients with an operative mortality of 5.1%. Overall survival and recurrence rate at 5 years was 43.6% and 74.2%, respectively. TNM Stage (P < 0.001) and the presence of fibrosis/cirrhosis (P = 0.002) were independent predictors of long-term survival in the Cox proportional hazards regression model. Both performing liver resection equal to or greater than hemihepatectomy and combined bile duct resection significantly increased overall survival [hazard ratio, HR = 0.61 (0.38-0.99); P = 0.044 and HR = 0.51 (0.31-0.84); P = 0.008, respectively] and decreased recurrence rate [HR = 0.59 (0.38-0.91); P = 0.018 and HR = 0.61 (0.42-0.89); P = 0.009, respectively]. CONCLUSIONS: Clinical outcomes were mostly influenced by tumor stage and underlying liver function, and the impact of BDTT to survival seemed less prominent than vascular invasion. Therefore, an aggressive surgical approach, including major liver resection combined with bile duct resection, to increase the chance of R0 resection is strongly recommended.

Hepatitis B Prophylaxis after Liver Transplantation in Korea: Analysis of the KOTRY Database.

BACKGROUND: Prophylaxis for hepatitis B virus (HBV) recurrence is essential after liver transplantation (LT) in HBV-associated recipients. We conducted real-world analysis of HBV prophylaxis after LT in the Korean population. METHODS: Korean Organ Transplantation Registry (KOTRY) database and additionally collected data (n = 326) were analyzed with special reference to types of HBV prophylaxis. RESULTS: The study cohort comprised 267 cases of living-donor LT and 59 cases of deceased-donor LT. Hepatocellular carcinoma (HCC) was diagnosed in 232 (71.2%) of these subjects. Antiviral agents were used in 255 patients (78.2%) prior to LT. HBV DNA was undetectable in 69 cases (21.2%) and detectable over wide concentrations in the other 257 patients (78.8%) prior to LT. Polymerase chain reaction analysis of the store blood samples detected HBV DNA in all patients, with 159 patients (48.9%) showing concentrations > 100 IU/mL. Post-transplant HBV regimens during the first year included combination therapy in 196 (60.1%), hepatitis B immunoglobulin (HBIG) monotherapy in 121 (37.1%), and antiviral monotherapy in 9 (2.8%). In the second post-transplant year, these regimens had changed to combination therapy in 187 (57.4%), HBIG monotherapy in 112 (34.4%), and antiviral monotherapy in 27 (8.3%). Trough antibody to hepatitis B surface antigen titers > 500 IU/mL and >1,000 IU/mL were observed in 61.7% and 25.2%, respectively. The mean simulative half-life of HBIG was 21.6 ± 4.3 days with a median 17.7 days. Up to 2-year follow-up period, HCC recurrence and HBV recurrence developed in 18 (5.5%) and 6 (1.8%), respectively. HCC recurrence developed in 3 of 6 patients with HBV recurrence. CONCLUSION: Combination therapy is the mainstay of HBV prophylaxis protocols in a majority of Korean LT centers, but HBIG was often administered excessively. Individualized optimization of HBIG treatments using SHL is necessary to adjust the HBIG infusion interval.

Longterm Analysis of Biliary Complications After Duct-to-Duct Biliary Reconstruction in Living Donor Liver Transplantations.

Biliary complication (BC) is still regarded as the Achilles' heel of a living donor liver transplantation (LDLT). This study aims to evaluate the longterm outcomes of the duct-to-duct (DD) biliary reconstruction using 7-0 suture and to identify the risk factors of BCs after LDLTs. Data of 140 LDLTs between 2006 and 2015 were analyzed. All biliary reconstructions were performed as DD anastomoses using 7-0 suture: 102 for the right lobe, 20 for the left lobe, and 18 for right posterior sector grafts. BC was defined as a bile leakage (BL) or a biliary stricture (BS), and the median follow-up time after LDLT was 65 months. A total of 19 recipients (13.5%) developed BCs (8 BLs and 16 BSs) after LDLT. The survival rates between recipients with and without BCs were 83% and 86.7%, respectively (P = 0.88). In univariate analyses, the risk factors for BC were small diameter of the graft's bile duct, long warm ischemic time, small graft-to-recipient weight ratio, and no use of external biliary stent (EBS). The graft's bile duct diameter ≤ 3 mm and no use of EBS were determined as independent risk factors (hazard ratios of 9.74 and 7.68, respectively) in multivariate analyses. The 116 recipients with EBS had no BL, 11 had BSs (9%), while 24 without EBS had 8 BLs (33%) and 5 BSs (21%). After a propensity score match between the recipients with and without EBS, the EBS group (24) developed only 1 BS (4%). In conclusion, DD anastomosis using 7-0 suture combined with EBS could provide favorable longterm outcomes after LDLT, which should thus be considered the surgical technique of choice for LDLTs.

Prognostic Prediction Models for Resection of Large Hepatocellular Carcinoma: A Korean Multicenter Study.

BACKGROUND: We developed a prognostic prediction model (PPM) using 4 factors for hepatic resection (HR) of large hepatic cellular carcinoma (HCC). Multiplication of α-fetoprotein (AFP), des-γ-carboxy prothrombin, and tumor volume (TV) (ADV score) is a surrogate marker for post-resection prognosis. This study intended to validate the predictive power of 4-factor PPM and to develop new ADV score-based PPM. METHODS: A total of 526 patients who underwent HR for solitary HCC ≥ 8 cm were selected from 9 Korean institutions between 2008 and 2014. RESULTS: Median tumor diameter and TV were 11.0 cm and 398 mL, respectively. Tumor recurrence and patient survival rates were 53.0 and 78.4% at 1 year and 70.2 and 49.3% at 5 years, respectively. Independent risk factors for both tumor recurrence and patient survival included AFP ≥ 100 ng/mL, hypermetabolic FDG-positron emission tomography (PET), microvascular invasion and satellite nodules, which comprised 4 factors of the PPM. Five subgroups based on the number of involved risk factors exhibited significant differences in tumor recurrence and patient survival. ADV score cutoff was set at 7log (ADV7log) after cluster prognostic analysis. Patient grouping according to combination of ADV7log and FDG-PET findings (ADV7log-PET) exhibited significant differences in tumor recurrence and patient survival, comparable to those of the 4-factor PPM. CONCLUSIONS: Two PPMs using 4 risk factors and ADV7log-PET could reliably predict the risk of early HCC recurrence and long-term survival outcomes in patients who underwent HR for large HCC. We believe that these PPMs can guide surgical treatment for large HCCs from preoperative HR planning to post-resection follow-up.

Donor safety in living donor liver transplantation: The Korean organ transplantation registry study.

Major concerns about donor safety cause controversy and limit the use of living donor liver transplantation to overcome organ shortages. The Korean Organ Transplantation Registry established a nationwide organ transplantation registration system in 2014. We reviewed the prospectively collected data of all 832 living liver donors who underwent procedures between April 2014 and December 2015. We allocated the donors to a left lobe group (n = 59) and a right lobe group (n = 773) and analyzed the relations between graft types and remaining liver volumes and complications (graded using the Clavien 5-tier grading system). The median follow-up was 19 months (range, 10-31 months). During the study period, 553 men and 279 women donated livers, and there were no deaths after living liver donation. The overall, biliary, and major complication (grade ≥ III) rates were 9.3%, 1.7%, and 1.9%, respectively. The graft types and remaining liver volume were associated with significantly different overall, biliary, and major complication rates. Of the 16 patients with major complications, 9 (56.3%) involved biliary complications (2 biliary strictures [12.5%] and 7 bile leakages [43.8%]). Among the 832 donors, the mean aspartate transaminase, alanine aminotransferase, and total bilirubin levels were 23.9 ± 8.1 IU/L, 20.9 ± 11.3 IU/L, and 0.8 ± 0.4 mg/dL, respectively, 6 months after liver donation. In conclusion, biliary complications were the most common types of major morbidity in living liver donors. Donor hepatectomy can be performed successfully with minimal and easily controlled complications. Our study shows that prospective, nationwide cohort data provide an important means of investigating the safety in living liver donation. Liver Transplantation 23 999-1006 2017 AASLD.

Plugged percutaneous biopsy of the liver in living-donor liver transplantation recipients suspected to have graft rejection.

Background Percutaneous biopsy is a widely-accepted technique for acquiring histologic samples of the liver. When there is concern for bleeding, plugged percutaneous biopsy (PPB) may be performed, which involves embolization of the biopsy tract. Purpose To evaluate the efficacy and safety of PPB of the liver in patients suspected to have graft rejection after living-donor liver transplantation (LDLT). Material and Methods During January 2007 and December 2013, 51 patients who underwent PPB of the liver under the suspicion of post-LDLT graft rejection were retrospectively analyzed. A total of 73 biopsies were performed. Biopsy was performed with a 17-gauge core needle and 18-gauge cutting needle. The needle tract was embolized using gelatin sponge (n = 44) or N-butyl cyanoacrylate (NBCA) (n = 29). The specimens were reviewed to determine their adequacy for histologic diagnosis. We reviewed all medical records after PPB. Results Specimens were successfully acquired in all procedures (100%). They were adequate for diagnosis in 70 cases (95.9%) and inadequate in three (1.3%). Average of 9.8 complete portal tracts was counted per specimen. One minor complication (1.4%) occurred where the patient had transient fever after the procedure. Conclusion PPB is easy and safe to perform in LDLT recipients and provides high diagnostic yield.

Prognostic significance of microvascular invasion in tumor stage for hepatocellular carcinoma.

BACKGROUND: The presence of microvascular invasion (McVI) in hepatocellular carcinoma (HCC) has been proposed as a cause of recurrence and poor survival, although this has not been officially emphasized in staging systems. Thus, we conducted a retrospective study to investigate the prognostic importance of McVI in tumor staging in patients with HCC who underwent hepatic resection. METHODS: A retrospective analysis was performed of patients who underwent hepatic resection for HCC at our center from 1994 to 2012. Patients with HCC were classified into four groups based on the presence of McVI and extent of gross vascular invasion (VI). RESULTS: The 5-year overall and recurrence-free survival rates of 676 patients were 63.3 and 42.6%, respectively. There was no difference in tumor recurrence or survival rate between patients with HCC and McVI without gross VI and those with gross VI confined to segmental/sectional branches. Multivariate analysis revealed that the extent of VI based on the presence of McVI and gross VI was independently associated with tumor recurrence and overall survival. CONCLUSIONS: McVI was revealed to be an important risk factor similar to gross VI confined to a segmental/sectional branch in patients with HCC who underwent hepatic resection. This finding should be considered when estimating the stage for prognosis.

Quantitative Assessment of the Portal Pressure for the Liver Surgery Using Serological Tests.

OBJECTIVE: To establish a reliable equation to predict hepatic venous pressure gradient (HVPG) using serological tests for surgical patients with hepatocellular carcinoma (HCC). BACKGROUND: Accurate assessment of portal pressure for surgical patients with HCC is important for safe hepatic resection (HR). The HVPG is regarded as the most reliable method to detect portal hypertension. However, HVPG is not utilized in many medical centers due to invasiveness of procedure. METHODS: Between 2006 and 2008, 171 patients (Correlation cohort), who underwent liver surgery in a tertiary hospital, were enrolled. Preoperative measurements of the HVPG and serological tests were performed simultaneously. Correlation between the HVPG and serological tests were analyzed to establish an equation for calculated HVPG (cHVPG). Between 2008 and 2013, 510 surgical patients (Application cohort) were evaluated, and HR recommended when cHVPG < 10 mm Hg. The outcomes of HR were analyzed to evaluate reliability of the cHVPG for HR. RESULTS: In the correlation cohort, the equation for cHVPG was established using multivariate linear regression analysis; cHVPG (mm Hg) = 0.209 × [ICG-R15 (%)] - 1.646 × [albumin (g/dL)] - 0.01×[platelet count (10)] + 1.669 × [PT-INR] + 8.911. In the application cohort, 425 patients with cHVPG < 10 mm Hg underwent HR. Among them, 357 had favorable value of ICG-R15 < 20% (group A), and 68 had unfavorable value of ICG-R15 ≥ 20% (group B). There was no significant difference in patient demographics, tumor characteristics, operative outcome, and survival rates between group A and B. CONCLUSIONS: The equation for cHVPG of this study was established on statistical reliability. The cHVPG could be useful to predict portal pressure quantitatively for surgical patients with HCC using serological tests.

Time of hepatocellular carcinoma recurrence after liver resection and alpha-fetoprotein are important prognostic factors for salvage liver transplantation.

Salvage liver transplantation (LT) is considered a feasible option for the treatment of recurrent hepatocellular carcinoma (HCC). We performed this multicenter study to assess the risk factors associated with the recurrence of HCC and patient survival after salvage LT. Between January 2000 and December 2011, 101 patients who had previously undergone liver resection (LR) for HCC underwent LT at 3 transplant centers in Korea. Sixty-nine patients' data were retrospectively reviewed for the analysis. The recurrence of HCC was diagnosed at a median of 10.6 months after the initial LR, and patients underwent salvage LT. Recurrences were within the Milan criteria in 48 cases and were outside the Milan criteria in 21 cases. After salvage LT, 31 patients had HCC recurrence during a median follow-up period of 24.5 months. There were 24 deaths, and 20 were due to HCC recurrence. The 5-year overall survival rate was approximately 54.6%, and the 5-year recurrence-free survival rate was 49.3%. HCC recurrence within the 8 months after LR [hazard ratio (HR) = 3.124, P = 0.009], an alpha-fetoprotein level higher than 200 ng/mL (HR = 2.609, P = 0.02), and HCC outside the Milan criteria at salvage LT (HR = 2.219, P = 0.03) were independent risk factors for poor recurrence-free survival after salvage LT. In conclusion, the timing and extent of HCC recurrence after primary LR both play significant roles in the outcome of salvage LT.

Small graft size and hepatocellular carcinoma outcomes in living donor liver transplantation: a retrospective multicentric cohort study.

INTRODUCTION: This study examined associations between the graft-to-recipient weight ratio (GRWR) for adult-to-adult living donor liver transplantation (LDLT) and HCC outcomes. MATERIALS AND METHODS: Data from patients in the Korean Organ Transplantation Registry who underwent LDLT for HCC from 2014-2021 were retrospectively reviewed. Patients were categorized using the cutoff GRWR for HCC recurrence determined by an adjusted cubic spline (GRWR<0.7% vs. GRWR≥0.7%). Recurrence-free survival (RFS) and HCC recurrence were analyzed in the entire and a 1:5 propensity-matched cohort. RESULTS: The eligible cohort consisted of 2005 LDLT recipients (GRWR<0.7 [n=59] vs. GRWR≥0.7 [n=1946]). In the entire cohort, 5-year RFS was significantly lower in the GRWR<0.7 than in the GRWR≥0.7 group (66.7% vs. 76.7%, P =0.019), although HCC recurrence was not different between groups (77.1% vs. 80.7%, P =0.234). This trend was similar in the matched cohort ( P =0.014 for RFS and P =0.096 for HCC recurrence). In multivariable analyses, GRWR<0.7 was an independent risk factor for RFS (adjusted HR [aHR] 1.89, P =0.012), but the result was marginal for HCC recurrence (aHR 1.61, P =0.066). In the pretransplant tumor burden subgroup analysis, GRWR<0.7 was a significant risk factor for both RFS and HCC recurrence only for tumors exceeding the Milan criteria (aHR 3.10, P <0.001 for RFS; aHR 2.92, P =0.003 for HCC recurrence) or with MoRAL scores in the fourth quartile (aHR 3.33, P <0.001 for RFS; aHR 2.61, P =0.019 for HCC recurrence). CONCLUSIONS: A GRWR<0.7 potentially leads to lower RFS and higher HCC recurrence after LDLT when the pretransplant tumor burden is high.

Surgical outcomes of hepatocellular carcinoma with bile duct tumor thrombus: a Korean multicenter study.

BACKGROUND: The long-term outcomes after resection for hepatocellular carcinoma (HCC) with macroscopic bile duct tumor thrombus (BDTT) are unclear. This multicenter study was conducted to determine the prognosis of HCC patients with macroscopic BDTT who underwent resection with curative intent. METHODS: Of 4,308 patients with HCC from four Korean institutions, this single-arm retrospective study included 73 patients (1.7 %) who underwent resection for HCC with BDTT. RESULTS: Jaundice was also present in 34 patients (46.6 %). According to Ueda classification, BDTT was type 2 in 34 cases (46.6 %) and type 3 in 39 cases (53.4 %). Biliary decompression was performed in 33 patients (45.2 %), decreasing the median lowest bilirubin level to 1.4 mg/dL before surgery. Systematic hepatectomy was performed in 69 patients (94.5 %), and concurrent bile duct resection was performed in 31 patients (42.5 %). Surgical curability types were R0 (n = 57; 78.1 %), R1 (n = 11; 15.1 %), and R2 (n = 5; 6.8 %). Patient survival rates were 76.5 % at 1 year, 41.4 % at 3 years, 32.0 % at 5 years, and 17.0 % at 10 years. Recurrence rates were 42.9 % at 1 year, 70.6 % at 3 years, 77.3 % at 5 years, and 81.1 % at 10 years. Results of univariate survival analysis showed that maximal tumor size, bile duct resection, and surgical curability were significant risk factors for survival, and surgical curability was a significant risk factor for recurrence. Multivariate analysis did not reveal any independent risk factors. CONCLUSIONS: Hepatocellular carcinoma patients with BDTT achieved relatively favorable long-term results after resection; therefore extensive surgery should be recommended when complete resection is anticipated.

Selection of Safe Donors for Living Donor Liver Transplant Using Extended Right Lobe Graft.

Extended right lobectomy (ERL) for living donor liver transplant (LDLT) is selectively performed in many transplant centers and has shown excellent recipient outcomes as reported in previous studies. Yet, there is no universally accepted indication for ERL in respect to donor safety. Current study was designed to stratify risk factors of adverse donor outcome after ERL. A total of 79 living donors who underwent ERL for LDLT were included in analysis. Donors were classified as safety and hazard donor groups according to postoperative findings relevant to posthepatectomy liver failure classification by the International Study Group for Liver Surgery. On multivariable analysis, left lateral section volume <20% of total liver volume and nonpreservation of segment 4a venous drainage were the independent risk factors impairing postoperative outcomes. Despite the short-term impairment of liver function in hazard donor groups, all donors recovered and showed satisfactory remnant liver regeneration. However, these findings have implications in establishing selection criteria of donors eligible for ERL donation. In conclusion, LDLT using ERL graft can be safely performed provided so that left lateral section volume/total donor liver is ≥20% besides conventional donor selection criteria. Also, efforts to preserve segment 4a vein must be made in performing ERL graft procurement in LDLT donors.

A New Method for Determination of Optimal Borehole Drilling Location Considering Drilling Cost Minimization and Sustainable Groundwater Management.

Drilling boreholes for the exploration of groundwater incurs high cost with potential risk of failures. However, borehole drilling should only be done in regions with a high probability of faster and easier access to water-bearing strata, so that groundwater resources can be effectively managed. However, regional strati-graphic uncertainties drive the decision of the optimal drilling location search. Unfortunately, due to the unavailability of a robust solution, most contemporary solutions rely on physical testing methods that are resource intensive. In this regard, a pilot study is conducted to determine the optimal borehole drilling location using a predictive optimization technique that takes strati-graphic uncertainties into account. The study is conducted in a localized region of the Republic of Korea using a real borehole data set. In this study we proposed an enhanced Firefly optimization algorithm based on an inertia weight approach to find an optimal location. The results of the classification and prediction model serve as an input to the optimization model to implement a well-crafted objective function. For predictive modeling a deep learning based chained multioutput prediction model is developed to predict groundwater-level and drilling depth. For classification of soil color and land-layer a weighted voting ensemble classification model based on Support Vector Machines, Gaussian Naïve Bayes, Random Forest, and Gradient Boosted Machine is developed. For weighted voting, an optimal set of weights is determined using a novel hybrid optimization algorithm. Experimental results validate the effectiveness of the proposed strategy. The proposed classification model achieved an accuracy of 93.45% and 95.34% for soil-color and land-layer, respectively. While the mean absolute error achieved by proposed prediction model for groundwater level and drilling depth is 2.89% and 3.11%, respectively. It is found that the proposed predictive optimization framework can adaptively determine the optimal borehole drilling locations for high strati-graphic uncertainty regions. The findings of the proposed study provide an opportunity to the drilling industry and groundwater boards to achieve sustainable resource management and optimal drilling performance.

Predictive worker safety assessment through on-site correspondence using multi-layer fuzzy logic in outdoor construction environments.

Construction sites remain highly perilous work environments globally, exposing employees to numerous hazards that can result in severe injuries or fatalities. To resolve this several solutions based on quantitative approaches have been developed. However the wide adoption of preexisting solutions is hindered by lack of accuracy. To this aim the development of an efficient fuzzy inference system has become a de-facto necessity. In this paper, we propose an edge inference framework based on multi-layered fuzzy logic for safety of construction workers. The proposed system employs an edge computing-based framework where IoT devices collect, store, and manage data to offer safety services. Multi-layer fuzzy logic is applied to infer the worker safety index based on rules that consist of construction environment factors. The multi-layer fuzzy logic is fed with weather, building and worker data collected from IoT nodes as inputs. The safety risk assessment process involves analyzing various factors. Weather information, such as temperature, humidity, and rainfall data, is considered to assess the risk to safety. The condition of the building is evaluated by analyzing load, strain, and inclination data. Additionally, the safety risk to workers is analyzed by taking into account their heart rate and location information. The initial layer's outputs are utilized as inputs for the subsequent layer, where an integrated safety index is inferred. Ultimately, the safety index is generated as the final outcome. The system's results are conveyed through warnings and an error measurement on a safety scale ranging from 1 to 10. Furthermore, web service is developed to allow the construction management to check the worker safety condition of the construction site in real-time, while also monitoring the operational status of the IoT devices, allowing for the early detection of sensor malfunction and the subsequent guarantee of worker safety. Extensive evaluations conducted to test the performance of the developed framework verify its efficiency to provide improved risk assessment, real-time monitoring, and proactive safety actions, encouraging a safer and more productive work environment.

Quantitative Prediction of Posttransplant Hepatocellular Carcinoma Prognosis Using ADV Score: Validation with Korea-Nationwide Transplantation Registry Database.

OBJECTIVE: The aim of this study is to validate the prognostic impact of ADV score (α-fetoprotein [AFP]-des-γ-carboxyprothrombin [DCP]-tumor volume [TV] score) for predicting prognosis of hepatocellular carcinoma (HCC) following liver transplantation (LT). BACKGROUND: ADV score has been reported as a prognostic surrogate biomarker of HCC following LT and hepatectomy. METHODS: The study patients were 1599 LT recipients selected from the Korean Organ Transplantation Registry database. RESULTS: Deceased-donor and living-donor LTs were performed in 143 and 1456 cases, respectively. Weak correlation was present among AFP, DCP, and TV. The viable HCC group showed ADV score-dependent disease-free survival (DFS) and overall patient survival (OS) rates from 1log to 10log (p<0.001). Prognosis of complete pathological response group was comparable to that of ADV score <1log (p≥0.099). ADV score cutoff of 5log (ADV-5log) for DFS and OS was obtained through receiver operating characteristic curve analysis with area under the curve ≥0.705. Both ADV-5log and Milan criteria were independent risk factors for DFS and OS, and their prognostic impacts were comparable to each other. Combination of these two factors resulted in further prognostic stratification, showing hazard ratios for DFS and OS as 2.98 and 2.26 respectively for one risk factor and 7.92 and 8.19 respectively for two risk factors (p<0.001). ABO-incompatible recipients with ADV score ≥8log or two risk factors showed higher recurrence rates. CONCLUSIONS: This validation study revealed that ADV score is a reliable surrogate biomarker for posttransplant HCC prognosis, which can be used for selecting LT candidates and guiding risk-based posttransplant follow-up surveillance.

The effect of donor against recipient one-way HLA mismatch on liver transplantation outcomes from a multicenter registry analysis.

Donor against recipient one-way Human leukocyte antigen (HLA) mismatch (D → R one-way HLA MM) seemed strongly associated with graft-versus-host disease (GVHD). The aim of this study is to investigate the relevance of D → R one-way HLA MM in outcome of liver transplantation (LT). We retrospectively analyzed 2670 patients in Korean Organ Transplantation Registry database between April 2014 and December 2020. The patients were categorized into two groups whether D → R one-way HLA MM or not and evaluated the outcomes of LT between the two groups. 18 patients were found to be D → R one-way HLA MM. The incidence of GVHD (0.3% vs. 22.2%, p < 0.001) and mortality rate (11.6% vs. 38.9%, p = 0.003) was much higher in D → R one-way HLA MM group. D → R one-way HLA MM at 3 loci was seemed to be strongly associated with the incidence of GVHD (OR 163.3, p < 0.001), and found to be the strongest risk factor for patient death (HR 12.75, p < 0.001). Patients with D → R one-way HLA MM at 3 loci showed significantly lower overall survival (p < 0.001) but there were no significant differences in rejection-free survival and death-censored graft survival. D → R one-way HLA MM at 3 loci not only affects the overall survival of LT patients but also the incidence of GVHD.