Outcome of patients undergoing right lobe living donor liver transplantation with small-for-size grafts

Post Living Donor Liver Transplantation Small-for-size Syndrome: Definitions, Timelines, Biochemical, and Clinical Factors for Diagnosis: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

When a partial liver graft is unable to meet the demands of the recipient, a clinical phenomenon, small-for-size syndrome (SFSS), may ensue. Clear definition, diagnosis, and management are needed to optimize transplant outcomes.

METHODS

A Consensus Scientific committee (106 members from 21 countries) performed an extensive literature review on specific aspects of SFSS, recommendations underwent blinded review by an independent panel, and discussion/voting on the recommendations occurred at the Consensus Conference.

RESULTS

The ideal graft-to-recipient weight ratio of ≥0.8% (or graft volume standard liver volume ratio of ≥40%) is recommended. It is also recommended to measure portal pressure or portal blood flow during living donor liver transplantation and maintain a postreperfusion portal pressure of <15 mm Hg and/or portal blood flow of <250 mL/min/100 g graft weight to optimize outcomes. The typical time point to diagnose SFSS is the postoperative day 7 to facilitate treatment and intervention. An objective 3-grade stratification of severity for protocolized management of SFSS is proposed.

CONCLUSIONS

The proposed grading system based on clinical and biochemical factors will help clinicians in the early identification of patients at risk of developing SFSS and institute timely therapeutic measures. The validity of this newly created grading system should be evaluated in future prospective studies.

Association between Hepatocellular Carcinoma Recurrence and Graft Size in Living Donor Liver Transplantation: A Systematic Review

The aim of this work was to assess the association between graft-to-recipient weight ratio (GRWR) in adult-to-adult living donor liver transplantation (LDLT) and hepatocellular carcinoma (HCC) recurrence. A search of the MEDLINE and EMBASE databases was performed until December 2022 for studies comparing different GRWRs in the prognosis of HCC recipients in LDLT. Data were pooled to evaluate 1- and 3-year survival rates. We identified three studies, including a total of 782 patients (168 GRWR < 0.8 vs. 614 GRWR ≥ 0.8%). The pooled overall survival was 85% and 77% at one year and 90% and 83% at three years for GRWR < 0.8 and GRWR ≥ 0.8, respectively. The largest series found that, in patients within Milan criteria, the GRWR was not associated with lower oncological outcomes. However, patients with HCC outside the Milan criteria with a GRWR < 0.8% had lower survival and higher tumor recurrence rates. The GRWR < 0.8% appears to be associated with lower survival rates in HCC recipients, particularly for candidates with tumors outside established HCC criteria. Although the data are scarce, the results of this study suggest that considering the individual GRWR not only as risk factor for small-for-size-syndrome but also as contributor to HCC recurrence in patients undergoing LDLT would be beneficial. Novel perfusion technologies and pharmacological interventions may contribute to improving outcomes.

The short- and long-term outcomes in living-donor liver transplantation using small-for-size graft: A systematic review and meta-analysis

BACKGROUND

A standard graft-to-recipient weight ratio (GRWR) ≥0.8% is widely accepted in living-donor liver transplantation (LDLT); however, the potential donor pool is expanded to patients adopting small-for-size graft (SFSGs) with GRWR <0.8%. This study aimed to investigate the effect of SFSG on short- and long-term outcomes following LDLT.

METHODS

Electronic databases were searched from January 1995 to January 2022 for studies comparing short- or long-term outcomes between patients with SFSG (GRWR <0.8%, SFSG group) and sufficient volume graft (GRWR ≥0.8%, non-SFSG group). The primary outcomes were one-, three-, and five-year overall survival (OS) and graft survival (GS), while the secondary outcome was postoperative complications.

RESULTS

Twenty-four studies comprising 7996 patients were included. In terms of OS, SFSG group had poor three-year OS (HR: 1.48, 95% CI [1.01, 2.15], p = 0.04), but there were no significant differences between two groups in one-year OS (HR: 1.50, 95% CI [0.98, 2.29], p = 0.06) and five-year OS (HR: 1.40, 95% CI [0.95, 2.08], p = 0.02). In GS, there were no significant differences in one-year (HR 1.31, 95% CI [1.00, 1.72], p = 0.05), three-year (HR 1.33, 95% CI [0.97, 1.82], p = 0.07), and five-year GS (HR 1.17, 95% CI [0.95, 1.44], p = 0.13). The SFSG group had comparable postoperative complications, except for a high incidence of vascular complications and small-for-size syndromes.

CONCLUSIONS

Expanding the potential donor pool in LDLT to SFSG with GRWR <0.8% can be acceptable in terms of comparable long-term OS and GS, despite the risk for vascular complications and small-for-size syndrome.

The role of graft to recipient weight ratio on enhanced recovery of the recipient after living donor liver transplantation - A systematic review of the literature and expert panel recommendations

BACKGROUND

There continues to be debate about the lower limit of graft-to-recipient weight ratio (GRWR) for living donor liver transplant (LDLT).

OBJECTIVES

To identify the lower limit of GRWR compatible with enhanced recovery after living donor liver transplant and to provide international expert panel recommendations.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Studies assessing how GRWR affects recipient outcomes such as small for size syndrome, other complications, patient and graft survival, and length of stay were included.

PROTOCOL REGISTRATION

CRD42021260794.

RESULTS

Twenty articles were included in the qualitative synthesis, and all were retrospective observational studies. There was heterogeneity in the definition of study cohorts and key outcome measures such as small-for-size syndrome. Most studies lacked risk adjustment given limited single-center sample size. GRWR of ≥ .8% is associated with enhanced recovery. Recipients of grafts with GRWR < .8%, however, were found to have similar outcomes as those with ≥ .8% when appropriate consideration is made for portal flow modulation and recipient illness severity.

CONCLUSIONS

GRWR ≥ .8% is often compatible with enhanced recovery, but grafts < .8% can be used in selected LDLT recipients with optimal donor-recipient selection, surgical technique, and perioperative management (Quality of Evidence; Low | Grade of Recommendation; Strong).

Small-For-Size Syndrome and Graft Inflow Modulation Techniques in Liver Transplantation

BACKGROUND

Partial liver transplantation has recently been proposed to alleviate organ shortages. However, transplantation of a small-for-size graft is associated with an increased risk of posttransplant hepatic dysfunction, commonly referred to as small-for-size syndrome (SFSS). This review describes the etiology, pathological features, clinical manifestations, and diagnostic criteria of SFSS. Moreover, we summarize strategies to improve graft function, focusing on graft inflow modulation techniques. Finally, unmet needs and future perspectives are discussed.

SUMMARY

In fact, posttransplant SFSS can be attributed to various factors such as preoperative status of the recipients, surgical techniques, donor age, and graft quality, except for graft size. With targeted improvement measures, satisfactory clinical outcomes can be achieved in recipients at increased risk of SFSS. Given the critical role of relative portal hyperperfusion in the pathogenesis of SFSS, various pharmacological and surgical treatments have been established to reduce or partially divert excessive portal inflow, and recipients will benefit from individualized therapeutic regimens after careful evaluation of benefits against potential risks. However, there remain unmet needs for further research into different aspects of SFSS to better understand the correlation between portal hemodynamics and patient outcomes.

KEY MESSAGES

Contemporary transplant surgeons should consider various donor and recipient factors and develop case-specific prevention and treatment strategies to improve graft and recipient survival rates.

Current status of left lobe adult to adult living donor liver transplantation

PURPOSE OF REVIEW

This review describes the history and current state of left lobe living donor liver transplantation (LDLT). The transplant community continues to face an organ shortage on a global scale, and the expansion of LDLT is attractive because it allows us to provide life-saving liver transplants to individuals without drawing from, or depending on, the limited deceased donor pool. Donor safety is paramount in LDLT, and for this reason, left lobe LDLT is particularly attractive because the donor is left with a larger remnant.

RECENT FINDINGS

This article reviews the donor and recipient evaluations for left lobe LDLT, discusses small for size syndrome and the importance of portal inflow modification, and reviews recipient outcomes in right lobe versus left lobe LDLT.

SUMMARY

Left lobe LDLT was the first adult-to-adult LDLT ever to be performed in Japan in 1993. Since that time, the use of both right and left lobe LDLT has expanded immensely. Recent work in left lobe LDLT has emphasized the need for inflow modification to reduce portal hyperperfusion and early graft dysfunction following transplant. Accumulating evidence suggests, however, that even though early graft dysfunction following LDLT may prolong hospitalization, it does not predict graft or patient survival.

The Enhancing Effects of S-Allylcysteine on Liver Regeneration Are Associated with Increased Expression of mRNAs Encoding IGF-1 and Its Receptor in Two-Thirds Partially Hepatectomized Rats

Two-thirds partial hepatectomy (PHx) was performed in rats, and the differences in effects between S-allylcysteine (SAC) and other sulfur-containing compounds on regeneration of the remaining liver and restoration of the injury were examined. Three days after two-thirds PHx, rats treated with 300 mg/kg/d, per os (p.o.) SAC showed a 1.2-fold increase in liver weight per 100 g body weight compared with saline-treated controls. In contrast, S-methylcysteine (SMC) (300 mg/kg/d, p.o.) or cysteine (Cys) (300 mg/kg/d, p.o.) did not have a regeneration-promoting effect. In the comparison with control rats, the regenerating liver of SAC-treated rats showed a significantly higher 5-bromo-2'-deoxyuridine labeling index on day 1. In contrast, serum alanine aminotransferase activity, which increases following PHx, was significantly inhibited by SAC and SMC (but not Cys) on day 1 after two-thirds PHx. In addition, SAC induced increases in insulin-like growth factor (IGF)-1 and its receptor mRNA expressions at 1 h after two-thirds PHx, and it increased phosphorylation of extracellular signal-regulated kinase (ERK)2 and Akt at 3 h after two-thirds PHx without affecting serum growth hormone levels. These results demonstrate that SAC is a mitogenic effector of normal remnant liver and promotes recuperation of liver function after two-thirds PHx. Moreover, SAC-induced proliferative effects are mediated via increased mRNA expressions of IGF-1 and its receptor and subsequent phosphorylation of ERK2 and Akt.

Association of Graft-to-Recipient Weight Ratio with the Prognosis Following Liver Transplantation: a Meta-analysis

BACKGROUND

Studies indicate that low graft-to-recipient weight ratio (GRWR) affect graft survival in adult-to-adult living donor liver transplantation. However, the potential role of GRWR in the prognosis of patients following living donor liver transplantation according to patient characteristics remains controversial. This study aimed to update the role of GRWR in patients following living donor liver transplantation.

METHODS

PubMed, Embase, and Cochrane Library were comprehensively searched for studies comparing low GRWR (< 0.8%) with normal GRWR (≥ 0.8%) in the prognosis following living donor liver transplantation from inception to March 2019. The 1-, 3-, and 5-year summary survival rates, small-for-size syndrome (SFSS), perioperative mortality, biliary complications, postoperative bleeding, and acute rejection were calculated using the random-effects model.

RESULTS

Eighteen studies comprising 4001 patients were included. Patients with low GRWR were associated with lower 1-year and 3-year survival rates compared to patients with normal GRWR, while no significant difference was found in the association of 5-year survival rate with low and normal GRWRs. Moreover, the risk of SFSS significantly increased in patients with low GRWR. Finally, no significant differences were observed in the association of low and normal GRWRs with the risk of perioperative mortality, biliary complications, postoperative bleeding, and acute rejection.

CONCLUSION

The results of this study indicated that low GRWR was associated with poor prognosis for patients following living donor liver transplantation, especially in terms of 1- and 3-year survival rates and SFSS.

Secondary non-resectable liver tumors: A single-center living-donor and deceased-donor liver transplantation case series

BACKGROUND

During the last decades, deceased-donor liver transplantation (DDLT) has gained a place in the therapeutic algorithm of well-selected patients harbouring non-resectable secondary liver tumors. Living-donor LT (LDLT) might represent a valuable means to further expand this indication for LT.

METHODS

Between 1985 and 2016, twenty-two adults were transplanted because of neuroendocrine (n = 18, 82%) and colorectal metastases (n = 4, 18%); 50% received DDLT and 50% LDLT. In LDLT, 4 (36%) right and 7 (64%) left grafts were used; the median graft-to-recipient-weight ratios (GRWR) were 1.03% (IQR 0.86%-1.30%) and 0.59% (IQR 0.51%-0.91%), respectively. Median post-LT follow-up was 64 months (IQR 17-107) in the DDLT group and 40 months (IQR 35-116) in the LDLT group. DDLT and LDLT recipients were compared in terms of overall survival, graft survival, postoperative complications and recurrence.

RESULTS

The 1- and 5-year actuarial patient survivals were 82% and 55% after DDLT, 100% and 100% after LDLT, respectively (P < 0.01). One- and 5-year actuarial graft survivals were 73% and 36% after DDLT, 91% and 91% after LDLT (P < 0.01). The outcomes of right or left LDLT were comparable. Donor hepatectomy proved safe, and one donor experienced a Clavien IIIb complication. Bilirubin peak was significantly lower after left hepatectomy compared with that after right hepatectomy [1.3 (IQR 1.2-2.2) vs. 3.3 (IQR 2.3-5.2) mg/dL; P = 0.02].

CONCLUSIONS

The more recent LDLT series compared favorably to our DDLT series in the treatment of secondary liver malignancies. The absence of portal hypertension and the use of smaller left grafts make recipient and donor surgeries safe. The safety of the procedures and lack of interference with the scarce allograft pool are expected to lead to a more frequent use of LDLT in the field of transplant oncology.

Outcomes of adult patients adopting small-for-size grafts in living donor liver transplantation: A systematic review and meta-analysis

BACKGROUND

Small-for-size graft (SFSG) has emerged as one of the very contentions in adult-to-adult living donor liver transplantation (LDLT) as a certain graft size is related to recipients' prognosis. Graft-to-recipient weight ratio (GRWR) ≥0.8% was considered as a threshold to conduct LDLT. However, this also has been challenged over decades as a result of technique refinements. For a better understanding of SFSG in practice, we conducted this meta-analysis to compare the perioperative outcomes and long-term outcomes between patients adopting the grafts with a lower volume (GRWR < 0.8%, SFSG group) and sufficient volume (GRWR ≥ 0.8%, non-SFSG group) in adult-to-adult LDLT.

DATA SOURCES

The studies comparing recipients adopting graft with a GRWR < 0.8% and ≥ 0.8% were searched by three authors independently in PubMed, Web of Science, Embase, the Cochrane Library, MEDLINE and Google Scholar databases until September 2018 and data were analyzed by RevMan 5.3.5.

RESULTS

Sixteen studies with a total of 3272 subjects were included in this meta-analysis. In terms of small-for-size syndrome (SFSS), no significant difference was found in subjects enrolled after year 2010 (before 2010, OR=3.00, 95% CI: 1.69-5.35, P = 0.0002; after 2010, OR=1.23, 95% CI: 0.79-1.90, P = 0.36; P for interaction: 0.02). There was no significant difference in operative duration, blood loss, cold ischemia time, biliary complications, acute rejection, postoperative bleeding, hospitalization time, perioperative mortality, and 1-, 3- and 5-year overall survival rates between two groups.

CONCLUSIONS

This meta-analysis suggested that adopting SFSG in adult LDLT has comparable outcomes to those with non-SFSG counterparts since 2010.

Albumin-Bilirubin Score for Predicting Post-Transplant Complications Following Adult-to-Adult Living Donor Liver Transplantation

Background

Albumin-Bilirubin (ALBI) grade has been evaluated as an objective method to assess liver function and predict postoperative complications, particularly after hepatectomy in patients with hepatocellular carcinoma (HCC). However, ALBI grade was rarely used in evaluation in living donor liver transplantation (LDLT).

Material/Methods

Between March 2005 and November 2015, 272 consecutive patients undergoing right-lobe LDLT were enrolled in this study. According to the ALBI score used to evaluate recipients preoperatively, those patients were divided into 3 grades (I, II, and III). Demographic findings and the post-operative complication rates were collected and compared among groups.

Results

The proportions of massive blood cell transfusions were different among those 3 grades (p<0.05). The patients in grade III had a higher risk of bacterial pneumonia and early allograft dysfunction (EAD) compared to grade I (p=0.029 and p=0.038, respectively) and grade II (p=0.006 and p=0.007, respectively). The area under the receiver operating characteristic curve of ALBI, Child-Pugh, and MELD for predicting 30-day mortality were 0.702 (95% CI: 0.644–0.756), 0.669 (95% CI: 0.580–0.697, p=0.510, versus ALBI grade), and 0.540 (95% CI: 0.580–0.697, p=0.144, versus ALBI grade), respectively.

Conclusions

ALBI grade was a good index for predicting post-operative complications and had a predictive ability similar to those of the Child-Pugh classification and MELD score.

Feasibility of using marginal liver grafts in living donor liver transplantation

Liver transplantation (LT) is one of the most effective treatments for end-stage liver disease caused by related risk factors when liver resection is contraindicated. Additionally, despite the decrease in the prevalence of hepatitis B virus (HBV) over the past two decades, the absolute number of HBsAg-positive people has increased, leading to an increase in HBV-related liver cirrhosis and hepatocellular carcinoma. Consequently, a large demand exists for LT. While the wait time for patients on the donor list is, to some degree, shorter due to the development of living donor liver transplantation (LDLT), there is still a shortage of liver grafts. Furthermore, recipients often suffer from emergent conditions, such as liver dysfunction or even hepatic encephalopathy, which can lead to a limited choice in grafts. To expand the pool of available liver grafts, one option is the use of organs that were previously considered “unusable” by many, which are often labeled “marginal” organs. Many previous studies have reported on the possibilities of using marginal grafts in orthotopic LT; however, there is still a lack of discussion on this topic, especially regarding the feasibility of using marginal grafts in LDLT. Therefore, the present review aimed to summarize the feasibility of using marginal liver grafts for LDLT and discuss the possibility of expanding the application of these grafts.

Liver paired exchange: Can the liver emulate the kidney?

Kidney paired exchange (KPE) constitutes 12% of all living donor kidney transplantations (LDKTs) in the United States. The success of KPE programs has prompted many in the liver transplant community to consider the possibility of liver paired exchange (LPE). Though the idea seems promising, the application has been limited to a handful of centers in Asia. In this article, we consider the indications, logistical issues, and ethics for establishing a LPE program in the United States with reference to the principles and advances developed from experience with KPE. Liver Transplantation 24 677-686 2018 AASLD.

The error analysis of Lobular and segmental division of right liver by volume measurement

The aim of this study is to explore the inconsistencies between right liver volume as measured by imaging and the actual anatomical appearance of the right lobe. Five healthy donated livers were studied. The liver slices were obtained with hepatic segments multicolor-infused through the portal vein. In the slices, the lobes were divided by two methods: radiological landmarks and real anatomical boundaries. The areas of the right anterior lobe (RAL) and right posterior lobe (RPL) on each slice were measured using Photoshop CS5 and AutoCAD, and the volumes of the two lobes were calculated. There was no statistically significant difference between the volumes of the RAL or RPL as measured by the radiological landmarks (RL) and anatomical boundaries (AB) methods. However, the curves of the square error value of the RAL and RPL measured using CT showed that the three lowest points were at the cranial, intermediate, and caudal levels. The U- or V-shaped curves of the square error rate of the RAL and RPL revealed that the lowest value is at the intermediate level and the highest at the cranial and caudal levels. On CT images, less accurate landmarks were used to divide the RAL and RPL at the cranial and caudal layers. The measured volumes of hepatic segments VIII and VI would be less than their true values, and the measured volumes of hepatic segments VII and V would be greater than their true values, according to radiological landmarks. Clin. Anat. 30:585-590, 2017. © 2017 Wiley Periodicals, Inc.

Small-for-size syndrome in live donor liver transplantation-Pathways of injury and therapeutic strategies

Due to the severe organ shortage and the increasing gap between the supply and demand for donor grafts, live donor liver transplantation (LDLT) has become an accepted and alternative technique for the expansion of the donor pool. However, donor safety and good recipient outcomes must be balanced regarding risk stratification and decision-making within this patient population. Small-for-size syndrome (SFSS) is one of the complications encountered after LDLT, thus increasing the burden of optimizing donor graft selection and effective treatments during its occurrence. A graft-to-recipient weight ratio (GRWR) <0.8 predisposes the graft to SFSS. However, other factors may induce this complication even without a graft-to-patient size mismatch. Several strategies to prevent this complication include portal vein flow and liver outflow modulation, as well as pharmacological treatment. Also, as an entity with a multifactorial etiology, outcomes vary between right-lobe, left-lobe, and posterior-lobe donation among series encountered in the literature. In this review, we analyze the pathophysiology and classification of this complication, the state-of-the-art on management of SFSS, and the outcomes regarding the best treatment strategy on this patient population.

Adult to adult right lobe living donor liver transplantation: does biological relationship matter?

The influence of the biological relationship between the donor and the recipient is rarely discussed in living donor liver transplantation (LDLT), although it is believed to be an important risk factor in other types of organ transplantations. A total of 272 consecutive patients undergoing adult to adult right lobe LDLT were retrospectively analyzed and stratified into a nonbiologically related (NBR) group (69 patients) and a biologically related (BR) group (203 patients). The preoperative data and postoperative outcomes of both recipients and donors were evaluated.More than two-thirds of the recipients had histories of HBV infection, and hepatocellular carcinoma (HCC) was the main reason for the patients undergoing LDLT in both groups. The percentage of female donors in the NBR group was more than the percentage in the BR group (P = 0.000). There were no differences between the groups in postoperative laboratory testing or daily immunosuppression dose, and the complication rates in both the recipient and donor surgeries showed no significant differences. For patients with benign diseases, the cumulative 1-, 3-, 5-, and 10-year survival rate were 92.9% in the 4 periods in the NBR group and 89.1%, 87.6%, 83.7%, and 83.7%, respectively, in BR group, while for the patients diagnosed as HCC, if patients exceeding the Milan criteria were involved, the 5-year survival rate was 41.2%, compared to 82% for patients within the Milan criteria, which was nearly the same as for those with the benign disease. In conclusion, our findings suggested that the biological relationship between the donor and the recipient in adult to adult LDLT was not associated with the short- and long-term outcomes of recipients diagnosed with benign liver diseases and early stage HCC. Moreover, the criteria for patients diagnosed with HCC to undergo LDLT should be restrictively selected.

Small for Size and Flow (SFSF) syndrome: An alternative description for posthepatectomy liver failure

Small for Size Syndrome (SFSS) syndrome is a recognizable clinical syndrome occurring in the presence of a reduced mass of liver, which is insufficient to maintain normal liver function. A definition has yet to be fully clarified, but it is a common clinical syndrome following partial liver transplantation and extended hepatectomy, which is characterized by postoperative liver dysfunction with prolonged cholestasis and coagulopathy, portal hypertension, and ascites. So far, this syndrome has been discussed with focus on the remnant size of the liver after partial liver transplantation or extended hepatectomy. However, the current viewpoints believe that the excessive flow of portal vein for the volume of the liver parenchyma leads to over-pressure, sinusoidal endothelial damages and haemorrhage. The new hypothesis declares that in both extended hepatectomy and partial liver transplantation, progression of Small for Size Syndrome is not determined only by the "size" of the liver graft or remnant, but by the hemodynamic parameters of the hepatic circulation, especially portal vein flow. Therefore, we suggest the term "Small for Size and Flow (SFSF)" for this syndrome. We believe that it is important for liver surgeons to know the pathogenesis and manifestation of this syndrome to react early enough preventing non-reversible tissue damages.

Donor Safety in Adult-Adult Living Donor Liver Transplantation: A Single-Center Experience of 356 Cases

Background

As an important means to tackle the worldwide shortage of liver grafts, adult-adult living donor liver transplantation (A-ALDLT) is the most massive operation a healthy person could undergo, so donor safety is of prime importance. However, most previous research focused on recipients, while complications in donors have not been fully described or investigated.

Material/Methods

To investigate donor safety in terms of postoperative complications, the clinical data of 356 A-ALDLT donors in our center from January 2002 to September 2015 were retrospectively analyzed. These patients were divided into a pre-2008 group (before January 2008) and a post-2008 group (after January 2008). Donor safety was evaluated with regard to the type, frequency, and severity of postoperative complications.

Results

There were no donor deaths in our center during this period. The overall complication rate was 23.0% (82/356). The proportion of Clavien I, II, III, and IV complications was 51.2% (42/82), 25.6% (21/82), 22.0% (18/82), and 1.2% (1/82), respectively. In all the donors, the incidence of Clavien I, II, III, and IV complications was 11.8% (42/356), 5.9% (21/356), 5.1% (18/356), and 0.3% (1/356), respectively. The overall complication rate in the post-2008 group was significantly lower than that in the pre-2008 group (18.1% (41/227) vs. 32.6% (42/129), P<0.01). Biliary complications were the most common, with an incidence of 8.4% (30/356).

Conclusions

The risk to A-ALDLT donors is controllable and acceptable with improvement in preoperative assessment and liver surgery.

Influence of graft size matching on outcomes of infantile living donor liver transplantation

We aimed to assess the impact of size mismatching between grafts and recipients on outcomes of infants or small children after LDLT. Between October 2006 and December 2014, 129 LDLT recipients weighing no more than 8 kg were retrospectively analyzed. The entire cohort was categorized into three groups by GRWR: GRWR < 3.0% (group A, n = 38), 3.0% ≤ GRWR < 4.0% (group B, n = 61), and GRWR ≥ 4.0% (group C, n = 30). Baseline characteristics were similar among groups A, B, and C. Compared with groups A and B, post-transplant alanine aminotransferase and aspartate aminotransferase within seven days were significantly higher in group C; however, differences between total bilirubin and albumin after transplantation were not prominent. Moreover, incidences of surgical complications, perioperative deaths, infections, and acute rejections were all comparable among the three groups. Five-yr patient survival rates for groups A, B, and C were 89.5%, 88.9%, and 81.6%, respectively (p = 0.872), and the graft survival rates were 89.5%, 86.6%, and 81.6%, respectively (p = 0.846). In conclusion, GRWR between 1.9% and 5.8% would not cause noticeable adverse events for infantile LDLT recipients ≤ 8 kg. However, there is still a role for considering reduction in the graft mass as an applicable strategy in selected cases.

Durability of small-for-size living donor allografts

Our aim was to study the long-term outcomes of living donor liver transplantation using small-for-size (SFS) grafts. From July 2002 to July 2009, 233 patients received a right liver graft with a middle hepatic vein from a living donor in our center. Recipients were stratified according to the graft weight to recipient standard liver volume (GW/SLV) ratio into 4 groups: >50% (n = 89), >40% to 50% (n = 85), >35% to 40% (n = 38), and ≤ 35% (n = 21). They were compared in terms of graft survivals, biliary stricture rates, renal function in terms of estimated glomerular filtration rate (eGFR), platelet counts, and graft function in terms of serum bilirubin and international normalized ratio (INR). The 5-year graft survivals for patients with GW/SLV of >50%, >40% to 50%, >35% to 40% and ≤ 35% were 88.8%, 88.2%, 81.5%, and 81.0%, respectively. Transplantation for hepatocellular carcinoma affected graft survivals (P = 0.02), but graft size did not (P = 0.66). There were no differences in frequency of biliary stricture (21.3% versus 17.1% versus 21.1% versus 28.6%; P = 0.75). At each year after transplant, their platelet counts (P = 0.12-0.65), eGFR (P = 0.49-0.91), bilirubin (P = 0.14-0.51), and INR (P = 0.20-0.98) remained comparable. SFS grafts with GW/SLV ≤ 35% and >35% to 40% had comparable long-term outcomes with larger liver grafts. Graft size did not affect long-term graft survivals.

Comparison of Different Scoring Systems Based on Both Donor and Recipient Characteristics for Predicting Outcome after Living Donor Liver Transplantation

BACKGROUND AND OBJECTIVES

In order to provide a good match between donor and recipient in liver transplantation, four scoring systems [the product of donor age and Model for End-stage Liver Disease score (D-MELD), the score to predict survival outcomes following liver transplantation (SOFT), the balance of risk score (BAR), and the transplant risk index (TRI)] based on both donor and recipient parameters were designed. This study was conducted to evaluate the performance of the four scores in living donor liver transplantation (LDLT) and compare them with the MELD score.

PATIENTS AND METHODS

The clinical data of 249 adult patients undergoing LDLT in our center were retrospectively evaluated. The area under the receiver operating characteristic curves (AUCs) of each score were calculated and compared at 1-, 3-, 6-month and 1-year after LDLT.

RESULTS

The BAR at 1-, 3-, 6-month and 1-year after LDLT and the D-MELD and TRI at 1-, 3- and 6-month after LDLT showed acceptable performances in the prediction of survival (AUC>0.6), while the SOFT showed poor discrimination at 6-month after LDLT (AUC = 0.569). In addition, the D-MELD and BAR displayed positive correlations with the length of ICU stay (D-MELD, p = 0.025; BAR, p = 0.022). The SOFT was correlated with the time of mechanical ventilation (p = 0.022).

CONCLUSION

The D-MELD, BAR and TRI provided acceptable performance in predicting survival after LDLT. However, even though these scoring systems were based on both donor and recipient parameters, only the BAR provided better performance than the MELD in predicting 1-year survival after LDLT.

Reversible immortalization of human hepatocytes mediated by retroviral transfer and site-specific recombination

AIM: To establish a method for the reversible immortalization of human hepatocytes, which may offer a good and safe source of hepatocytes for practical applications.

METHODS: We successfully isolated primary human hepatocytes from surgically resected liver tissue taken from a patient with liver hemangiomas. The freshly isolated cells were then immortalized with retroviral vector SSR#69 expressing simian virus 40 large T antigen (SV40T) and hygromycin-resistance genes flanked by paired loxP recombination targets.

RESULTS: The freshly isolated hepatocytes with high viability (85%) were successfully immortalized using retroviral gene transfer of SV40T. SV40T in the immortalized cells was then excised by Cre/loxP site-specific recombination. This cell population exhibited the characteristics of differentiated hepatocytes.

CONCLUSION: We successfully established reversibly immortalized human hepatocytes, which will provide an unlimited supply of cells for practical applications.