Microsteatosis may not interact with macrosteatosis in living donor liver transplantation

The impact of macro- and micro-steatosis on the outcomes of patients who undergo liver transplant: Analysis of the UNOS-STAR database

BACKGROUND AND AIMS

The presence of steatosis in a donor liver and its relation to post-transplantation outcomes are not well defined. This study evaluates the effect of the presence and severity of micro- and macro-steatosis of a donor graft on post-transplantation outcomes.

METHODS

The UNOS-STAR registry (2005-2019) was used to select patients who received a liver transplant graft with hepatic steatosis. The study cohort was stratified by the presence of macro- or micro-vesicular steatosis, and further stratified by histologic grade of steatosis. The primary endpoints of all-cause mortality and graft failure were compared using sequential Cox regression analysis. Analysis of specific causes of mortality was further performed.

RESULTS

There were 9184 with no macro-steatosis (control), 150 with grade 3 macro-steatosis, 822 with grade 2 macro-steatosis and 12 585 with grade 1 macro-steatosis. There were 10 320 without micro-steatosis (control), 478 with grade 3 micro-steatosis, 1539 with grade 2 micro-steatosis and 10 404 with grade 1 micro-steatosis. There was no significant difference in all-cause mortality or graft failure among recipients who received a donor organ with any evidence of macro- or micro-steatosis, compared to those receiving non-steatotic grafts. There was increased mortality due to cardiac arrest among recipients of a grade 2 macro-steatosis donor organ.

CONCLUSION

This study shows no significant difference in all-cause mortality or graft failure among recipients who received a donor liver with any degree of micro- or macro-steatosis. Further analysis identified increased mortality due to specific aetiologies among recipients receiving donor organs with varying grades of macro- and micro-steatosis.

Clinical Application of Infrared Spectroscopy in Liver Transplantation for Rapid Assessment of Lipid Content in Liver Graft

Liver transplantation (LT) is a major treatment for patients with end-stage liver diseases. Steatosis is a significant risk factor for primary graft nonfunction and associated with poor long-term graft outcomes. Traditionally, the evaluation of steatosis is based on frozen section examination to estimate the percentage of hepatocytes containing lipid vesicles. However, this visual evaluation correlates poorly with the true lipid content. This study aimed to address the potential of infrared (IR) microspectroscopy for rapidly estimating lipid content in the context of LT and assessing its impact on survival. Clinical data were collected for >20 months from 58 patients who underwent transplantation. For each liver graft, macrovacuolar steatosis and microvesicular steatosis were evaluated through histologic examination of frozen tissue section. Triglycerides (TG) were further quantified using gas phase chromatography coupled with a flame ionization detector (GC-FID) and estimated by IR microspectroscopy. A linear relationship and significant correlation were observed between the TG measured by GC-FID and those estimated using IR microspectroscopy (R2 = 0.86). In some cases, microvesicular steatosis was related to high lipid content despite low levels of macrovacuolar steatosis. Seven patients experienced posttransplantation liver failure, including 5 deceased patients. All patients underwent transplantation with grafts containing significantly high TG levels. A concentration of 250 nmol/mg was identified as the threshold above which the risk of failure after LT significantly increased, affecting 35% of patients. Our study established a strong correlation between LT outcomes and lipid content. IR microspectroscopy proved to be a rapid and reliable approach for assessing the lipid content in clinical settings.

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

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

Changing Trends in Liver Transplantation: Challenges and Solutions

Despite improvements in postliver transplant outcomes through refinements in perioperative management and surgical techniques, several changing trends in liver transplantation have presented challenges. Mortality on the waitlist remains high. In the United States, Europe, and the United Kingdom, there is an increasing need for liver transplantation, primarily as a result of increased incidence of nonalcoholic steatohepatitis-related cirrhosis and cancer indications. Meanwhile, donor suitability has decreased, as donors are often older and have more comorbidities. Despite a mismatch between organ need and availability, many organs are discarded. Notwithstanding this, many solutions have been developed to overcome these challenges. Innovative techniques in allograft preservation, viability assessment, and reconditioning have allowed the use of suboptimal organs with adequate results. Refinements in surgical procedures, including live donor liver transplantations, have increased the organ pool and are decreasing the time and mortality on the waitlist. Despite many challenges, a similar number of solutions and prospects are on the horizon. This review seeks to explore the changing trends and challenges in liver transplantation and highlight possible solutions and future directions.

Sex difference in the tolerance of hepatic ischemia-reperfusion injury and hepatic estrogen receptor expression according to age and macrosteatosis in healthy living liver donors

BACKGROUND

Hepatic estrogen signaling, which is important in liver injury/recovery, is determined by the level of systemic estrogen and hepatic estrogen receptor. We aimed to evaluate whether female's advantage in the tolerance of hepatic ischemia-reperfusion injury decreases according to the age of 40 y (systemic estrogen decrease) and macrosteatosis (hepatic estrogen receptor decrease).

METHODS

We included 358 living liver donors (128 females and 230 males). The tolerance of hepatic ischemia-reperfusion injury was determined by the slope of the linear regression line modeling the relationship between the duration of intraoperative hepatic ischemia and the peak postoperative transaminase level. Estrogen receptor content was measured in the biopsied liver samples using immunohistochemistry.

RESULTS

In the whole cohort, the regression slope for aspartate transaminase was comparable between females and males (P=0.940). Within the subgroup of ≤40 y donors, the regression slope was significantly smaller in females (P=0.031), whereas it was comparable within >40 y donors (P=0.867). Within the subgroup of ≤40 y non-macrosteatotic donors, the regression slope was significantly smaller in females in univariable (P=0.002) and multivariable analysis (P=0.006), whereas the sex difference was not found within ≤40 y macrosteatotic donors (P=0.685). Estrogen receptor content was significantly greater in females within ≤40 y non-macrosteatotic donors (P=0.021), whereas it was not different in others of >40 y or with macrosteatosis (P=0.450).

CONCLUSIONS

The tolerance of hepatic ischemia-reperfusion injury was greater in females than in males only when they were <40 y and without macrosteatosis. The results were in agreement with hepatic estrogen receptor immunohistochemistry study.

Clear mortality gap caused by graft macrosteatosis in Chinese patients after cadaveric liver transplantation

BACKGROUND

Liver transplantation (LT) is one of the most effective surgical treatment for patients with end-stage liver disease. Steatosis is a contributor for inferior graft quality. But its impact and safety on transplantation was less assessed in Chinese patients.

METHODS

Graft steatosis and related information involved in recipients, donors and surgical procedures were retrospectively collected from 239 patients.

RESULTS

Donor macrosteatosis (MaS) caused about 2.14 and 2.80 folds of increment on patient and graft mortality. Dose-response analysis revealed prominent risk of grafts on overall patient/organ mortality when MaS content exceeded 10% (P<0.05). Noteworthy, deaths were only observed in MaS group when concurrent with extremely higher post-transplant alanine aminotransferase (ALT, 64%). However, microsteatosis (MiS) grafts didn't affect outcomes after LT. In a cohort of Chinese patients, MaS had comprehensive effects on post-transplant outcomes with relatively lower safety threshold at 10%. Mortality gap caused by MaS grafts was observed in patients with severer ischemia reperfusion injury.

CONCLUSIONS

Our study revealled the graft MaS affected the post-transplant outcomes in lower risk cutoff in Chinese patients. Further study is worthy to validate these results and investigate inner mechanism under the phenomenon.

High prevalence of early atherosclerotic and cardiac damage in patients undergoing liver transplantation: Preliminary results

Liver transplanted patients are at high risk of metabolic syndrome and its complications. We aimed to prospectively evaluate the early onset of cardiovascular alterations in patients submitted to the transplant waiting list. From January 2014 to January 2016, 54 out of 79 patients on the waiting list with decompensated cirrhosis or hepatocellular-carcinoma received the transplant, 50 were followed for 24 months, 2 died post-surgery and 2 were lost to follow-up. A significantly increased prevalence of visceral adiposity (epicardial adipose tissue thickness (p = 0.001) and worsening of carotid damage (p = 0.003) and diastolic dysfunction (E/A p = 0.001) was observed at 6 months after transplant and remained stable at 24 months, corresponding to an increased prevalence of diabetes, metabolic syndrome, hypertension and dyslipidemia. The duration of steroid therapy, withdrawn in the majority of patients at 3 months, did not influence cardiovascular damage. No significant difference in early progression of cardiovascular damage was observed between patients who did or did not receive a graft with steatosis. CONCLUSION: The occurrence of early cardiovascular alterations in the first 6 months after OLT accounts for the reported cardiovascular events in the first years after transplant. In light of these results, new strategies aimed at preventing or delaying cardiovascular alterations should be provided, starting from the first weeks after transplant.

Systematic Evaluation of the Safety Threshold for Allograft Macrovesicular Steatosis in Cadaveric Liver Transplantation

Background: Currently, 30% macrovesicular steatosis (MaS) content is usually assigned empirically as the boundary between “use” and “refuse” a donor liver for liver transplantation (LT); however, this cut-off is questionable due to the lack of systemic evidence of the efficiency relative to prognosis prediction. Clinicians have tried to identify the threshold for optimized utilization of marginal steatotic allografts, but controversy exists among different studies.

Aim: Our study aimed to systematically determine an acceptable donor MaS content cut-off without incurring extra risk in liver transplantation, using meta-analysis.

Methods: The relevant literature reporting the relationship between MaS content and post-transplant mortality/morbidity was searched and retrieved in Pubmed, Embase, and ISI Web of Science.

Results: Nine studies were enrolled into the final analysis. A categorical comparison revealed that patients who received allografts with moderate steatosis (MaS content >30%) had significantly higher risks of graft failure/dysfunction, but not of mortality. Dose-response analysis showed that donor MaS content affected the graft failure/dysfunction in a non-linear relationship. Risks associated with MaS content in terms of poorer outcomes were independent of other risk covariates for liver transplantation. A non-significant increase in risk of inferior post-transplant outcomes was observed in patients who received allografts with a MaS content <35%. The risks of post-transplant graft failure and dysfunction increased with severe donor MaS content infiltration, without a consistent relationship.

Conclusions: The threshold of allograft MaS content can be safely extended to 35% without additional risk burden on post-transplant inferior outcomes. Clarification on “the effects of stratification” for MaS content can provide theoretical evidence for further optimal utilization of marginal steatotic allografts in liver transplantation.

Higher Risk of Posttransplant Liver Graft Failure in Male Recipients of Female Donor Grafts Might Not Be Due to Anastomotic Size Disparity

BACKGROUND

Posttransplant liver graft failure occurs most often in male recipients of livers from female donors. The respective role of donor sex itself and the size disparity in graft vessels/bile ducts according to donor sex are unclear. Thus, we aimed to evaluate the importance of donor sex with adjustment for anastomotic size disparity between female and male donor grafts.

METHODS

A total of 309 male patients without hepatic tumors who underwent living donor liver transplantation were analyzed (109 female donors and 200 male donors). The primary outcome was posttransplant graft failure (ie, retransplantation or death). Survival analysis was performed using the Cox model. Analyzed anastomosis-related factors comprised graft weight, number and size of hepatic vessels/bile ducts, and anastomosis techniques.

RESULTS

Graft failure probabilities at 1, 6, 12, 24, and 60 months posttransplantation were 9.1%, 19.5%, 20.2%, 23.0%, and 27.0%, respectively, with female donors and 2.0%, 5.5%, 8.1%, 10.1%, and 13.5% with male donors (hazards ratio [HR], 2.29; 95% confidence interval [CI], 1.35-3.88; P = 0.002). Multivariable analysis confirmed the significance of donor sex (HR, 2.30; 95% CI, 1.14-4.67; P = 0.021) after adjustment for anastomosis-related factors. All analyzed anastomosis-related factors showed no significant association with graft failure, although size of the graft hepatic artery showed marginal significance (HR, 0.50; 95% CI, 0.25-1.01; P = 0.053). The significance of donor sex was lost when donor was older than 36 to 40 years (age of poor ovarian reserve and the end of female fertility). Our institutional pediatric recipient cohort validated the inferiority of female-to-male donation.

CONCLUSIONS

Donor sex appears to be an independent factor modulating graft failure risk in male liver transplant recipients.

Short-term and long-term outcomes of liver transplantation using moderately and severely steatotic donor livers: A systematic review

BACKGROUND

The aim of this study was to perform a systemic review of the studies addressing the use of moderately and severely steatotic donor livers for liver transplantation.

METHODS

We searched the following electronic databases from January 1, 1989, to August 1, 2017: PubMed, EMBASE, Science Citation Index Expanded, and the Cochrane Library. In addition, reference lists were scanned to identify any additional reports. The quality of published papers was assessed. The main outcomes of the use of moderately and severely steatotic donor livers for liver transplantation, including primary nonfunction, short-term mortality, and long-term mortality, were extracted for pooled analysis.

RESULTS

Literature searches identified 16 studies that met the inclusion criteria. There were no randomized controlled studies, and all of the studies were retrospective or prospective case series. From a total of 3226 subjects (532 moderately and severely steatotic donor livers and 2694 controls), we found a significant increase in primary nonfunction [odds ratio (OR): 2.47, 95% confidence interval (95% CI): 1.44-4.27], and a trend of increase in 1-month patient mortality (OR: 1.90, 95% CI: 0.98-3.71) with the use of moderately and severely steatotic donor livers, whereas the 1-year mortality was relatively less influenced.

CONCLUSION

The use of moderately and severely steatotic livers is associated with unfavorable short-term outcomes, but long-term outcomes are relatively less influenced.

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.

Risk of posttransplant hepatocellular carcinoma recurrence is greater in recipients with higher platelet counts in living donor liver transplantation

Platelets interact with tumor cells and promote metastasis. The importance of platelets in posttransplant hepatocellular carcinoma (HCC) recurrence is unclear. Thus, we aimed to evaluate the association between preoperative platelet count (PLT) and HCC recurrence after living donor liver transplantation. Of 359 recipients of livers from living donors for HCC, 209 of 240 patients who had preoperative PLT ≤75 × 10⁹ /L were matched with 97 of 119 patients who had preoperative PLT >75 × 10⁹ /L using propensity score matching, with an unfixed matching ratio based on factors such as tumor biology. The cutoff value of 75 × 10⁹ /L was set based on optimum stratification analysis. Survival analysis was performed with death as a competing risk event. The primary outcome was overall HCC recurrence. The median follow-up time was 59 months. Before matching, recurrence probability at 1, 2, and 5 years after transplantation was 4.7%, 9.2%, and 11.3% for the low platelet group and 14.5%, 23.0%, and 30.5% for the high platelet group. Recurrence risk was significantly greater in the high platelet group in both univariate (hazard ratio [HR] = 3.09; 95% confidence interval [CI], 1.86-5.14; P < 0.001) and multivariate analyses (HR = 2.10; 95% CI, 1.23-3.60; P =  0.007). In the matched analysis, recurrence risk was also greater in the high platelet group in both univariate (HR = 2.33; 95% CI, 1.36-4.01; P =  0.002) and multivariate analyses (HR = 1.90; 95% CI, 1.02-3.54; P =  0.04). Preoperative PLT had no interaction with the Milan criteria, alpha-fetoprotein level, Edmonson grade, microvascular invasion, or intrahepatic metastasis. Incorporation of preoperative PLT into the Milan criteria significantly improved predictive power. Inflammation-based scores including neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and the inflammation-based index did not show superiority to preoperative PLT in predicting HCC recurrence. In conclusion, preoperative PLT appears to be an important host factor affecting HCC recurrence after living donor liver transplantation. Liver Transplantation 24 44-55 2018 AASLD.

Resolution of donor non-alcoholic fatty liver disease following liver transplantation

INTRODUCTION

Transplant surgeons conventionally select against livers displaying high degrees (>30%) of macrosteatosis (MaS), out of concern for primary non-function or severe graft dysfunction. As such, there is relatively limited experience with such livers, and the natural history remains incompletely characterized. We present our experience of transplanted livers with high degrees of MaS and microsteatosis (MiS), with a focus on the histopathologic and clinical outcomes.

METHODS

Twenty-nine cases were identified with liver biopsies available from both the donor and the corresponding liver transplant recipient. Donor liver biopsies displayed either MaS or MiS ≥15%, while all recipients received postoperative liver biopsies for cause.

RESULTS

The mean donor MaS and MiS were 15.6% (range 0%-60%) and 41.3% (7.5%-97.5%), respectively. MaS decreased significantly from donor (M=15.6%) to recipient postoperative biopsies (M=0.86%), P<.001. Similarly, MiS decreased significantly from donor biopsies (M=41.3%) to recipient postoperative biopsies (M=1.8%), P<.001. At a median of 68 days postoperatively (range 4-384), full resolution of MaS and MiS was observed in 27 of 29 recipients.

CONCLUSIONS

High degrees of MaS and MiS in donor livers resolve in recipients following liver transplantation. Further insight into the mechanisms responsible for treating fatty liver diseases could translate into therapeutic targets.

Association Between Intraoperative Platelet Transfusion and Early Graft Regeneration in Living Donor Liver Transplantation

OBJECTIVE

To evaluate the association between anesthetic management before and after graft reperfusion and early graft regeneration in living donor liver transplantation (LDLT).

BACKGROUND

Sufficient graft regeneration is essential for the success of LDLT. Diverse signals start to trigger liver regeneration immediately after graft reperfusion.

METHODS

Graft volume at 14 ± 2 days after LDLT was measured in 379 consecutive recipients using computed tomography images with 3-dimensional reconstruction. The association between anesthetic variables and the degree of graft regeneration for 2 weeks was analyzed using simple and multiple linear regressions. The anesthetic variables included hemodynamics, laboratory measurements, vasoactive drugs, and blood products transfusion.

RESULTS

The degree of graft regeneration for 2 weeks was 52% in median and ranged from 5% to 123%. Platelet transfusion was identified as the sole independent anesthetic factor contributing to graft regeneration. Platelet concentrate transfusion of 1 to 6 units vs none was correlated with a 6.5% increase in graft regeneration (P = 0.012). Platelet concentrate transfusion of more than 6 units vs none was further correlated with an 18.4% increase in regeneration (P < 0.001). In the subgroup of recipients without intraoperative platelet transfusion, mean platelet count measured during the intraoperative reperfusion phase was positively associated with graft regeneration (P = 0.033).

CONCLUSIONS

Graft regeneration after LDLT increased in relation to a graded increase in the amount of transfused platelets and higher postreperfusion platelet counts during surgery. These results offer additional evidence regarding the important role of platelets in initiating liver regeneration and, furthermore, the indications for and the benefits vs risks of platelet transfusion during LDLT.

NAFLD and liver transplantation: Current burden and expected challenges

Because of global epidemics of obesity and type 2 diabetes, the prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing both in Europe and the United States, becoming one of the most frequent causes of chronic liver disease and predictably, one of the leading causes of liver transplantation both for end-stage liver disease and hepatocellular carcinoma. For most transplant teams around the world this will raise many challenges in terms of pre- and post-transplant management. Here we review the multifaceted impact of NAFLD on liver transplantation and will discuss: (1) NAFLD as a frequent cause of cryptogenic cirrhosis, end-stage chronic liver disease, and hepatocellular carcinoma; (2) prevalence of NAFLD as an indication for liver transplantation both in Europe and the United States; (3) the impact of NAFLD on the donor pool; (4) the access of NAFLD patients to liver transplantation and their management on the waiting list in regard to metabolic, renal and vascular comorbidities; (5) the prevalence and consequences of post-transplant metabolic syndrome, recurrent and de novo NAFLD; (6) the alternative management and therapeutic options to improve the long-term outcomes with particular emphasis on the correction and control of metabolic comorbidities.

Association between Serum Bilirubin and Acute Intraoperative Hyperglycemia Induced by Prolonged Intermittent Hepatic Inflow Occlusion in Living Liver Donors

Background

Intermittent hepatic inflow occlusion (IHIO) is associated with acute hyperglycemia during living donor hepatectomy when the ischemia is prolonged. Bilirubin is a potent antioxidant to play an important role for maintaining insulin sensitivity and preventing hyperglycemia. Thus, we aimed to test whether serum bilirubin level is associated with prolonged IHIO-induced intraoperative hyperglycemia.

Methods

Seventy-five living liver donors who underwent a prolonged IHIO with a >30 minute cumulative ischemia were included. The association between preoperative serum bilirubin concentrations and the risk of intraoperative hyperglycemia (blood glucose concentration >180 mg/dl) was analyzed using binary logistic regression with adjusting for potential confounders including age and steatosis.

Results

The number of donors who underwent 3, 4, 5, and 6 rounds of IHIO was 41, 22, 7, and 5, respectively. Twenty-nine (35%) donors developed intraoperative hyperglycemia. Total bilirubin concentration was inversely associated with hyperglycemia risk (odds ratio [OR] 0.033, 95% confidence interval [CI] 0.004–0.313, P = 0.003). There was an interaction between age and total bilirubin concentration: the effect of lower serum total bilirubin (≤0.7 mg/dl) on the development of hyperglycemia was greater in older donors (>40 years) than in younger donors (P = 0.0.028 versus P = 0.212). Both conjugated bilirubin (OR 0.001 95% CI 0.001–0.684) and unconjugated bilirubin (OR 0.011 95% CI 0.001–0.246) showed an independent association with hyperglycemia risk.

Conclusions

Lower preoperative serum bilirubin was associated with greater risk of prolonged IHIO-induced hyperglycemia during living donor hepatectomy particularly in older donors. Thus, more meticulous glycemic management is recommended when prolonged IHIO is necessary for surgical purposes in old living donors with lower serum bilirubin levels.

Predicting Hepatic Steatosis in Living Liver Donors via Noninvasive Methods

Hepatic steatosis assessment is of paramount importance for living liver donor selection because significant hepatic steatosis can affect the postoperative outcome of recipients and the safety of the donor. The validity of various noninvasive imaging methods to assess hepatic steatosis remains controversial. The purpose of our study is to investigate the association between noninvasive imaging methods and pathology to detect steatosis in living liver donors and to propose a prediction model for hepatic steatosis. Liver stiffness measurements (LSMs) and controlled attenuation parameter values in vibration controlled transient elastography, ultrasonography, computed tomography (CT), and magnetic resonance imaging were used as pretransplant screening methods to evaluate living liver donors between 2012 and 2014. Only 1 pathologist assessed tissue sample for hepatic steatosis. The median age of the 79 living donors (53 men and 26 women) was 32 years (16-68 years). The CT liver-spleen attenuation (L-S) difference and the controlled attenuation parameter values were well correlated with the level of hepatic steatosis on liver pathology. Multivariate analysis showed that liver stiffness measurement (LSM) (β = 0.903; 95% CI, 0.105-1.702; P = 0.027) and the CT L to S attenuation difference (β = -3.322; 95% CI, -0.502 to -0.142; P = 0.001) were closely associated with hepatic steatosis. We generated the following equation to predict total hepatic steatosis: Hepatic steatosis = 0.903 × LSM - 0.322 × CT L to S attenuation difference (AUC = 86.6% and P = 0.001). The values predicted by the equation correlated well with the presence of hepatic steatosis (r = 0.509 and P < 0.001). The combination of nonenhanced CT L to S attenuation difference and transient elastography using vibration controlled transient elastography provides sufficient information to predict hepatic steatosis in living liver donor candidates.

Macrosteatotic and nonmacrosteatotic grafts respond differently to intermittent hepatic inflow occlusion: Comparison of recipient survival

Intermittent hepatic inflow occlusion (IHIO) during liver graft procurement is known to confer protection against graft ischemia/reperfusion injury and thus may benefit the recipient's outcome. We evaluated whether the protective effect of IHIO differs with the presence of macrosteatosis (MaS) and with an increase or decrease in the cumulative occlusion time. The subgroup of 188 recipients who received grafts with MaS was divided into 3 groups according to the number of total IHIO rounds during graft procurement: no IHIO, n = 70; 1 to 2 rounds of IHIO, n = 50; and ≥3 rounds of IHIO, n = 68. Likewise, the subgroup of 200 recipients who received grafts without MaS was divided into 3 groups: no IHIO, n = 108; 1 to 2 rounds of IHIO, n = 40; and ≥3 rounds of IHIO, n = 52. The Cox model was applied to evaluate the association between the number of total IHIO rounds and recipient survival separately in the subgroup of MaS recipients and the subgroup of non-MaS recipients. Analyzed covariables included the etiology, Milan criteria, transfusion, immunosuppression, and others. In the subgroup of MaS recipients, 1 to 2 rounds of IHIO were favorably associated with recipient survival [hazard ratio (HR), 0.29; 95% confidence interval (CI), 0.10-0.80; P = 0.03 after Bonferroni correction], whereas ≥3 rounds of IHIO were not associated with recipient survival (HR, 0.56; 95% CI, 0.25-1.23). In the subgroup of non-MaS recipients, neither 1 to 2 rounds of IHIO (HR, 0.69; 95% CI, 0.30-1.61) nor ≥3 rounds of IHIO (HR, 0.91; 95% CI, 0.42-1.96) were associated with recipient survival. In conclusion, 1 to 2 rounds of IHIO may be used for the procurement of MaS grafts with potential benefit for recipient survival, whereas IHIO has a limited impact on recipient survival regardless of the cumulative occlusion time when it is used for non-MaS grafts.