Hepatocellular uptake index obtained with gadoxetate disodium-enhanced magnetic resonance imaging in the assessment future liver remnant function after major hepatectomy for biliary malignancy.

BACKGROUND: Functional assessment of the future liver remnant (FLR) after major hepatectomy is essential but often difficult in patients with biliary malignancy, owing to obstructive jaundice and portal vein embolization. This study evaluated whether a novel index using gadoxetate disodium-enhanced MRI (EOB-MRI) could predict posthepatectomy liver failure (PHLF) after major hepatectomy for biliary malignancy. METHODS: The remnant hepatocellular uptake index (rHUI) was calculated in patients undergoing EOB-MRI before major hepatectomy for biliary malignancy. Receiver operating characteristic (ROC) curve analyses were used to evaluate the accuracy of rHUI for predicting PHLF grade B or C, according to International Study Group of Liver Surgery criteria. Multivariable logistic regression analyses comprised stepwise selection of parameters, including rHUI and other conventional indices. RESULTS: This study included 67 patients. The rHUI accurately predicted PHLF (area under the curve (AUC) 0.896). A cut-off value for rHUI of less than 0.410 predicted all patients who developed grade B or C PHLF. In multivariable analysis, only rHUI was an independent risk factor for grade B or C PHLF (odds ratio 2.0 × 103, 95 per cent c.i. 19.6 to 3.8 × 107; P < 0.001). In patients who underwent preoperative portal vein embolization, rHUI accurately predicted PHLF (AUC 0.885), whereas other conventional indices, such as the plasma disappearance rate of indocyanine green of the FLR and FLR volume, did not. CONCLUSION: The rHUI is potentially a useful predictor of PHLF after major hepatectomy for biliary malignancy.

C-reactive protein : albumin ratio in patients with resectable intrahepatic cholangiocarcinoma.

BACKGROUND: The C-reactive protein : albumin ratio (CAR) has been reported as a novel prognostic marker in several cancers. The aim of this study was to investigate the prognostic value of CAR in patients with intrahepatic cholangiocarcinoma (ICC). METHODS: This was a single-centre retrospective study of patients who underwent surgery for ICC in a university hospital in Japan between 1998 and 2018. CAR, Glasgow Prognostic Score (GPS) and modified GPS (mGPS) were calculated. Their correlation with recurrence-free survival (RFS) and overall survival (OS) was analysed with Cox proportional hazards models. RESULTS: Seventy-two patients were included in the study. Patients were divided into two groups according to the optimal CAR cut-off value of 0·02. CAR above 0·02 was associated with higher carbohydrate antigen 19-9 levels (20·5 versus 66·1 units/ml for CAR of 0·02 or less; P = 0·002), larger tumour size (3·2 versus 4·4 cm respectively; P = 0·031) and a higher rate of microvascular invasion (9 of 28 versus 25 of 44; P = 0·041). RFS and OS were shorter in patients with CAR above 0·02: hazard ratio (HR) 4·31 (95 per cent c.i. 2·02 to 10·63) and HR 4·80 (1·85 to 16·40) respectively. In multivariable analysis CAR above 0·02 was an independent prognostic factor of RFS (HR 3·29 (1·33 to 8·12); P < 0·001), but not OS. CONCLUSIONS: CAR was associated with prognosis in patients who had hepatic resection for ICC.

ANTECEDENTES: La relación proteína C reactiva/albumina (C-reactive protein/albumin ratio, CAR) ha sido descrita como un marcador pronóstico novedoso en varios tipos de cáncer. El objetivo de este estudio fue investigar el valor pronóstico de CAR en pacientes con colangiocarcinoma intrahepático (intrahepatic cholangiocarcinoma, ICC). MÉTODOS: Se trata de un estudio retrospectivo y unicéntrico de pacientes sometidos a cirugía por ICC en un hospital universitario de Japón entre 1998 y 2018. Se calcularon CAR, puntuación pronóstica de Glasgow (Glasgow prognostic score, GPS), y GPS modificada (mGPS). Se analizó su correlación con la supervivencia libre de recidiva (recurrence-free survival, RFS) y con la supervivencia global (overall survival, OS) mediante modelos de riesgos proporcionales de Cox. RESULTADOS: Se incluyeron un total de 72 pacientes. El valor de corte óptimo de CAR fue de 0,02. Los pacientes se dividieron en dos grupos de acuerdo a este valor de corte. La presencia de CAR > 0,02 se asoció con niveles más elevados de antígeno carbohidrato 19-9 (20,5 U/ml versus 66,1 U/ml; P = 0,002), mayor tamaño tumoral (3,2 cm versus 4,4 cm; P = 0,031) y una tasa más elevada de invasión microvascular (32,1% versus 56,8%; P = 0,041). La RFS y OS fueron más cortas en pacientes con CAR > 0,02 (cociente de riesgos instantáneos, hazard ratio, HR 4,305; i.c. del 95% 2,016-10,63 y HR 4,803; i.c. del 95% 1,846-16,40, respectivamente). En los análisis multivariables, CAR de > 0,02 fue un factor pronóstico independiente para RFS (HR 3,286; i.c. del 95% 1,330-8,118; P < 0,001), pero no para la OS. CONCLUSIÓN: CAR se asoció con el pronóstico en pacientes sometidos a resección hepática por ICC.

Real-Time Ultrasound-Guided Thrombectomy for Extensive Portal Vein Thrombosis in Living Donor Liver Transplantation.

Thrombectomy is a routine or common practice for treating organized portal vein thrombosis (PVT) during liver transplantation. However, this procedure is often performed in a blinded fashion and can result in insufficient thrombectomy or devastating consequences such as injury to the retropancreatic portal vein where prompt repair is very difficult. To overcome these drawbacks for blind thrombectomy, we herein describe a new technique that makes complex thrombectomy safe and easy under direct ultrasound vision. This procedure is readily available and highly reproducible and can be used as the standard procedure for treating extensive PVT.

Functional Analysis of Human Hepatocytes Isolated From Chimeric Mouse Liver.

Chimeric mice with humanized liver were first established by transplanting primary human hepatocytes (PHHs) isolated from a Japanese 27-year-old donor into complementary DNA-urokinase-type plasminogen activator/severe combined immunodeficiency mice. The PHHs from the Japanese donor increased more than 100-fold in the mouse liver, and human hepatocytes purified from the chimeric mouse liver (hcPHs) were successfully transplanted into second-passaged mice. These PHHs and hcPHs can produce human albumin and preserve many liver-specific enzyme genes, which are important for liver function. Interestingly, hepatitis B virus can be infected with these chimeric mice; hepatitis B viral DNA and hepatitis B surface antigen levels were detectable. In conclusion, hcPHs can be an ideal cell source for analysis of human hepatocytes.

Cytological diagnostic clues in poorly differentiated squamous cell carcinomas of the breast: Streaming arrangement, necrotic background, nucleolar enlargement and cannibalism of cancer cells.

OBJECTIVE: Squamous cell carcinoma (SCC) is a rare histological type of breast cancer. The cytological diagnosis of non-keratinising, poorly differentiated SCC is often difficult, and distinguishing it from invasive ductal carcinoma or apocrine carcinoma (AC) is especially challenging. We aimed to define the diagnostic cytological features of poorly differentiated SCC of the breast. METHODS: We studied the cytological findings of poorly differentiated SCC (n=10) and compared them to those of IDC (n=15) and AC (n=14). The following six cytological features were evaluated: streaming arrangement, nucleolar enlargement, dense nuclei, cannibalism, atypical keratinocytes and necrotic background. RESULTS: SCC exhibited significantly higher frequencies of streaming arrangement (70% vs 6.7%, P=.002), nucleolar enlargement (80% vs 27%, P=.02), and necrotic background (80% vs 36%, P=.002) than invasive ductal carcinoma. The detection of two or three of these features yielded a higher sensitivity (80%) and specificity (93%) for the diagnosis of SCC. Streaming arrangement (70% vs 0%, P<.001), cannibalism (60% vs 0%, P=.002), and a necrotic background (80% vs 36%, P=.047) were all significantly more frequent in SCC than in AC. When distinguishing SCC from AC, the presence of two or three of these features yielded a high sensitivity (80%) and specificity (100%). CONCLUSIONS: Cytological features such as a streaming arrangement, a necrotic background, nucleolar enlargement and cannibalism are useful indicators for the diagnosis of SCC of the breast. As such, greater attention should be paid to these morphological features in daily clinical practice.

Successful Recombinant Thrombomodulin Treatment for Thrombotic Microangiopathy After Liver Transplantation: A Case Report.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a rare but severe complication after liver transplantation. In contrast to other thrombotic microangiopathies, treatment for TA-TMA has yet to be clarified. A 52-year-old male patient with liver cirrhosis due to hepatitis C underwent split liver transplantation from a deceased donor. His clinical course was without complication until 4 days after transplantation, when he experienced impaired consciousness, hemolytic anemia with fragmented erythrocytes, and marked thrombocytopenia. TA-TMA was diagnosed, and recombinant thrombomodulin was administered for 4 days. The patient's clinical symptoms and laboratory data rapidly improved. He has been followed up for 6 months and has not shown any complications. The pathogenesis of TA-TMA is endothelial damage in the vasculature. Recombinant thrombomodulin, an endothelial cell-protecting agent, is a promising new therapeutic choice for TA-TMA after liver transplantation.

Clinical Outcomes of Living Liver Transplantation According to the Presence of Sarcopenia as Defined by Skeletal Muscle Mass, Hand Grip, and Gait Speed.

BACKGROUND: Sarcopenia is an independent predictor of death after living-donor liver transplantation (LDLT). However, the ability of the Asian Working Group for Sarcopenia criteria for sarcopenia (defined as reduced skeletal muscle mass plus low muscle strength) to predict surgical outcomes in patients who have undergone LDLT has not been determined. METHODS: This study prospectively enrolled 366 patients who underwent LDLT at Kyushu University Hospital. Skeletal muscle area (determined by computed tomography), hand-grip strength, and gait speed were measured in 102 patients before LDLT. We investigated the relationship between sarcopenia and surgical outcomes after LDLT performed in three time periods. RESULTS: The number of patients with lower skeletal muscle area has increased to 52.9% in recent years. The incidence of sarcopenia according to the Asian Working Group for Sarcopenia criteria was 23.5% (24/102). Patients with sarcopenia (defined by skeletal muscle area and functional parameters) had significantly lower skeletal muscle area and weaker hand-grip strength than did those without sarcopenia. Compared with non-sarcopenic patients, patients with sarcopenia also had significantly worse liver function, greater estimated blood loss, greater incidence of postoperative complications of Clavien-Dindo grade IV or greater (including amount of ascites on postoperative day 14, total bilirubin on postoperative day 14, and postoperative sepsis), and longer postoperative hospital stay. Multiple logistic regression analysis revealed sarcopenia as a significant predictor of 6-month mortality. CONCLUSIONS: The combination of skeletal muscle mass and function can predict surgical outcomes in LDLT patients.

Cytological markers for predicting ALK-positive pulmonary adenocarcinoma.

BACKGROUND: ALK gene rearrangement is an important class of gene mutations in pulmonary adenocarcinoma. ALK-positive pulmonary adenocarcinoma exhibits characteristic histological features, such as signet ring cell carcinoma (SRCC) and a mucinous cribriform structure. However, when insufficient histological specimens are obtained, ALK-positivity must be predicted based on cytological features. The purpose of this study was to clarify the cytological characteristics of ALK-positive pulmonary adenocarcinoma. METHODS: We compared the cytological findings of 16 ALK-positive cases with 40 ALK-negative cases. We examined various cytoplasmic features of SRCC, including the presence of pink, yellow, or orange mucin; green, vacuolar, or vesicular cytoplasm; and green globular cytoplasmic secretions. We also examined whether the SRCC cells exhibited a pattern of individually scattered cells, the formation of cell clusters, and formation of a mucinous cribriform pattern. RESULTS: A univariate analysis showed that significantly frequent cytological findings included pink mucin, green cytoplasm, vacuolar cytoplasm, vesicular cytoplasm, green globular cytoplasmic secretions, an individually scattered pattern, cluster formation, and a mucinous cribriform structure (all, P < .05). A stepwise multivariate logistic regression analysis identified three significant contributing factors: pink mucin (P = .03), vesicular cytoplasm (P = .06), and an individually scattered pattern (P = .01) of SRCC. If the specimens showed two or three of these features, the sensitivity and specificity were both 88% for the prediction of ALK-positive cancers. CONCLUSION: Three cytological features of SRCC (pink mucin, vesicular cytoplasm, and an individually scattered pattern) could be useful cytological markers for the prediction of ALK-positive pulmonary adenocarcinoma.

In Situ Posterior Graft Segmentectomy for Large-for-Size Syndrome in Deceased Donor Liver Transplantation in Adults: A Case Report.

Large-for-size syndrome (LFSS) is controversial in pediatric living donor liver transplantation patients and is associated with a poor graft outcome. Similar situations in deceased donor liver transplantation (DDLT) in adults have not been reported frequently, and there are no official guidelines worldwide. Deceased donation is extremely limited in Japan, and when a larger liver is allocated for a very sick small recipient in Japan, transplantation with a plan to address LFSS might be necessary. The patient is a 58-year-old female patient who had acute liver failure with coma. The graft-recipient weight ratio (GRWR) was 2.74%. Although the graft was enlarged by reperfusion, the intraoperative Doppler ultrasound, performed after reperfusion, showed sufficient graft in-flow and out-flow. However, when the liver graft was situated appropriately into the right phrenic space supported by the rib cage and diaphragm, the blood flow in the hepatic vein and portal vein was significantly reduced. Graft blood flow did not improve without removing it from the right subphrenic space. Therefore, we decided to perform an in situ graft posterior segmentectomy, so that the graft right lobe was properly accommodated in the patient's right subphrenic space. After the segmentectomy of the graft, an intraoperative Doppler sonogram showed significantly improved blood flow. LFSS could be a significant operative challenge in adult DDLT, especially in areas with limited chances of DDLT. In situ posterior segmentectomy in the demarcated area could be a solution for treating patients with LFSS.

Duct-to-duct Biliary Reconstruction in Living-donor Liver Transplantation for Primary Sclerosing Cholangitis: Report of a Case.

Although Roux-en Y hepaticojejunostomy was previously recommended for the biliary reconstruction in liver transplantation for primary sclerosing cholangitis (PSC), some recent reports showed no difference in the graft survival between Roux-en Y and duct-to-duct anastomosis in deceased-donor liver transplantation. On the other hand, considering the risk of recurrence and the short length of the bile duct of the graft, duct-to-duct biliary anastomosis has never been reported in a patient undergoing living-donor liver transplantation (LDLT) for PSC. A 45 year-old male underwent LDLT using a left-lobe graft donated from his brother. Cholangiography showed no lesion in his common bile duct and duct-to-duct anastomosis was chosen for him. Fifteen months later, he suffered cholangitis due to PSC recurrence and endoscopic retrograde cholangiography was performed. The stents were inserted into his B2 and B3, and he remains well. Because of the ability to easily manage biliary complication, duct-to-duct biliary reconstruction may become the first choice in LDLT for PSC without common bile duct lesions.

In Situ Procurement of a Recipient's Portal Vein for a Right Lobe Liver Graft With Multiple Venous Orifices: A Case Report.

Reconstruction of multiple venous orifices of a right lobe graft is a time-consuming and troublesome procedure in right lobe living-donor liver transplantation. In the current study, we present a new venous reconstruction technique for a right lobe graft with multiple and complex hepatic vein (HV) orifices, in which procurement of the recipient's left portal vein was performed in situ to keep the anhepatic period to a minimum. All of the HV orifices were reconstructed together at the back table, while maintaining patency of the recipient's systemic and splanchnic circulation. A homologous vein graft and veno-venous bypass were not necessary. All HVs were patent during the follow-up and the patient was free from complications. In conclusion, the present technique is readily available for reconstruction of complex and multiple HV tributaries, while avoiding a long anhepatic time and the use of veno-venous bypass.

Impact of platelets and serotonin on liver regeneration after living donor hepatectomy.

BACKGROUND: Several animal models have revealed that platelet-derived serotonin initiates liver regeneration after hepatectomy. However, there are few reports regarding the effects of serotonin in the clinical setting. The aim of this study was to explore the impact of serotonin and platelets in the early phase after healthy living donor hepatectomy. STUDY DESIGN: Stored samples from 34 living donors who received left lobectomy with caudate lobectomy (LL+C) or right lobectomy (RL) were available in the study. Serum serotonin levels and platelet counts associated with liver regeneration such as whole liver volume and hepatic graft weight (GW) were retrospectively collected from the database and analyzed. RESULTS: The remnant liver volume rate of RL grafts was smaller than that of LL+C grafts (45.4% vs 64.7%; P < .001). The regeneration rate at 7 days after surgery did not differ between the 2 groups (123% vs 122%). The serotonin levels and platelet counts decreased after surgery until postoperative day 3, then increased thereafter. The platelet counts and serotonin levels of LL+C donors were significantly higher than those of RL donors. CONCLUSIONS: Our findings suggest that platelets and serotonin play a pivotal role in initiating liver regeneration in the remnant liver.

Triple therapy using direct-acting agents for recurrent hepatitis C after liver transplantation: a single-center experience.

BACKGROUND: Hepatitis C viral graft reinfection is almost a universal event after liver transplantation with consequent disease progression. METHODS: We applied triple therapy (n = 21) with the use of telaprevir (TVR; n = 12) or simeprevir (SVR; n = 9). RESULTS: TVR was given at the dose 1,500 mg daily (n = 11) with reduced dose of cyclosporine at 25% to 50%, and SVR was given at the dose 100 mg daily with unadjusted cyclosporine, followed by 12 weeks of dual therapy. The early viral response was achieved in 91.7% (n = 11), end of treatment response rate was 91.7% (n = 11), and sustained viral response rate was 83.3% (n = 10) in the TVR group, and respective rates were 88.9% (n = 8), 77.8% (n = 7), and 77.8% (n = 7) in the SVR group. Although granulocyte colony-stimulating factor was not given in the patients with triple therapy, blood transfusion was performed in 7 cases (58.3%) in the TVR group and 1 case (11.1%) in the SVR group. Interferon-mediated graft dysfunction was observed in 4 cases (33.3%) in the TVR group and 3 cases (33.3%) in the SVR group, respectively. The cumulative viral clearance rates in triple (n = 21) and dual (n = 105) therapy were 95.0% and 18.1% at 12 weeks, and 95.0% and 40.0%, respectively, at 24 weeks (P < .01). CONCLUSIONS: Although careful monitoring for possible adverse events is required during treatment, triple therapy with the use of direct-acting agents are very effective in treating hepatitis C after liver transplantation.

Prognostic impact of des-γ-carboxyl prothrombin in living-donor liver transplantation for recurrent hepatocellular carcinoma.

BACKGROUND: Although the Milan criteria are widely accepted for liver transplantation (LT) in patients for hepatocellular carcinoma (HCC), they have not been fully evaluated for salvage LT in patients with recurrent HCC. We have previously reported outcomes of living-donor LT (LDLT) for HCC and identified 2 risk factors affecting recurrence-free survival (RFS): tumor size >5 cm and des-γ-carboxyl prothrombin (DCP) concentration >300 mAU/mL (Kyushu University criteria). This study was designed to clarify risk factors for tumor recurrence after LDLT in patients with recurrent HCC. METHODS: Outcomes in 114 patients who underwent LDLT for recurrent HCC were analyzed retrospectively. RFS rates after LDLT were calculated, and risk factors for tumor recurrence were identified. RESULTS: The 1-, 3-, and 5-year RFS rates after LDLT were 90.6%, 80.4%, and 78.8%, respectively. Univariate analysis showed that tumor recurrence was associated with alpha-fetoprotein concentration ≥ 300 ng/mL, DCP concentration ≥ 300 mAU/mL, tumor number ≥ 4, tumor size ≥ 5 cm, transarterial chemotherapy before LDLT, duration of last treatment of HCC to LDLT <3 months, bilobar distribution, exceeding Milan criteria, exceeding Kyushu University criteria, poor differentiation, and histologic vascular invasion. Multivariate analysis showed that DCP ≥ 300 mAU/mL (P = .03) and duration from last treatment to LDLT <3 months (P = .01) were independent predictors of RFS. CONCLUSIONS: DCP concentration and time between last treatment and LDLT are prognostic of RFS in patients undergoing LDLT for HCC.

Chronic immune-mediated reaction syndrome as the cause of late graft mortality in living-donor liver transplantation for primary biliary cirrhosis.

INTRODUCTION: Few studies to date have investigated the causes of late graft mortality after living-donor liver transplantation (LDLT) for primary biliary cirrhosis (PBC). PATIENTS AND METHODS: Fifty-five LDLTs for PBC were retrospectively reviewed. Factors prognostic of graft survival after LDLT were investigated, and histologic findings in patients with late graft loss were assessed. RESULTS: The 1-, 5-, and 10-year cumulative graft survival rates were 85.1%, 82.5%, and 66.9%, respectively. Multivariate Cox regression analysis found that male donor and ≥ 4 HLA mismatches were independently associated with poor graft survival. Among the 13 grafts lost, 5 were lost >1 year after LDLT, including 1 each due to chronic rejection, veno-occlusive disease, and obliterative portal venopathy, and 2 to other causes. Pathologic reviews of the serial biopsy specimens and explanted grafts from these 5 patients, with graft rejections from "chronic immune-mediated reaction syndrome," showed reciprocal changes over time. No patient died of recurrent PBC. CONCLUSIONS: Male donor and ≥ 4 HLA mismatches were independent factors associated with poor graft survival. Late graft mortality after LDLT for PBC in some patients was due to chronic immune-mediated reaction syndrome, including chronic rejection, veno-occlusive disease, and obliterative portal venopathy, but not to recurrent PBC.

Interferon-lambda4 genetic polymorphism is associated with the therapy response for hepatitis C virus recurrence after a living donor liver transplant.

The standard therapy against hepatitis C virus (HCV) recurrence postliver transplantation includes interferon (IFN)α and ribavirin. IFNL4 ss469415590 polymorphism has been reported as a novel predictor of the response to IFN therapy for chronic HCV infection. We examined the impact of IFNL4 polymorphism on the responsiveness to IFN therapy after liver transplantation. Tissue specimens were collected from 80 HCV-infected recipients and 78 liver donors, and their IFNL4 ss469415590 genotype, hepatic IFNL4 and interferon-stimulated genes' mRNA expression levels were examined. The association of the polymorphism and expression levels in terms of the IFN therapy response to HCV recurrence was analysed. Most individuals who had rs8099917 risk alleles also had ss469415590 risk alleles (R(2) = 0.9). Sustained virological response (SVR) rates were higher in both liver graft recipients and transplants with ss469415590 TT/TT alleles than in those with the risk ΔG allele (P = 0.003 and P = 0.005, respectively). In recipients with ss469415590 TT/TT, IFNL4 TT mRNA levels showed no significant differences between livers of patients who responded to therapy and those who did not (P = 0.4). In recipients with the risk ΔG allele, IFNL4 ΔG mRNA expression levels were significantly lower in SVR patients than in non-SVR patients (P = 0.02). Hepatic interferon stimulable genes and IFNL4 mRNA expression were correlated. Our findings suggest that analysing the ss469415590 genotype and IFNL4 ΔG expression provides a novel prediction strategy for the possible response to IFN therapy after liver transplantation.

Application of postoperative Model for End-Stage Liver Disease scoring system for evaluating liver graft function after living donor liver transplantation.

BACKGROUND: The Model for End-Stage Liver Disease (MELD) score has been validated to predict the mortality rate of patients with various chronic liver diseases on the waiting list for liver transplantation (LT). The aim of this study was to assess the value of the postoperative MELD scoring system as an early postoperative predictor of outcome in patients undergoing living donor LT (LDLT). METHODS: A retrospective analysis of 217 adult-to-adult LDLT patients was performed. The values of the MELD score on various postoperative days (PODs) as predictors of graft loss within 6 months after LDLT were examined by calculating the areas under the receiver operating characteristic (AUROC) curves. The 6-months graft survival rates were compared between patients with (n = 22) and without (n = 195) graft loss. Univariate and multivariate analyses were performed to identify the factors associated with mortality. RESULTS: The MELD score on POD2 was a predictor of graft loss, with an AUROC c-statistic of 0.779, a specificity of 79.5%, and a sensitivity of 68.2% at optimal cutoff, whereas the preoperative MELD score c-statistic was 0.605 with 44.6% sensitivity. Multivariate analyses for postoperative mortality revealed MELD-POD2 ≥19 (odds ratio, 5.601; 95% confidence interval [CI], 1.395-4.508; P = .0009) as an independent predictor of short-term graft loss following LDLT, in addition to preoperative hospitalization status. Later MELD POD scores were also predictive of graft loss. CONCLUSIONS: The early postoperative MELD scoring system is feasible as an index for prediction of postoperative mortality following LDLT.