Risk Factors for Intractable Ascites After Adult-to-Adult Living Donor Liver Transplantation Using Left Lobe. Transplant Direct. 2017;3:e138. [PMID: 28361122 PMCID: PMC5367755 DOI: 10.1097/txd.0000000000000652]

Establishment and validation of a predictive model of immune tolerance after pediatric liver transplantation: a multicenter cohort study

JOURNAL/ijos/04.03/01279778-202409000-00031/figure1/v/2024-09-12T150105Z/r/image-jpeg

Background:

Side-effect of life-long immunosuppressants (IS) administration is a major obstacle for the long-term survival of pediatric liver transplantation (LT) recipients. Immunotolerance is the status that recipients discontinued IS with normal liver function and intrahepatic histology. So far, only a few clinical parameters were identified related with tolerance but failed to accurately discriminate tolerant recipients in clinical practice. Here, the authors aimed to provide a comprehensive view of pre-LT and post-LT risk factors associated with the achievement of tolerance after pediatric LT and established a tolerance predictive nomogram (ITPLT) with high accuracy and specificity.

Methods:

The authors enrolled 2228 pediatric recipients who received LT in Renji Hospital between October 2006 and December 2020. All participants survived over 3 years after transplantation with comprehensive and intact medical history and follow-up data. They were randomly assigned to training and validation cohorts in accordance with a ratio of 1:1. Univariate and multivariable Logistic regression were used to identify clinical factors associated with post-LT immune tolerance and establish a predictive model. The model was further validated in an independent external validation cohort from Tianjin First Central Hospital.

Results:

Among all participants, 6% recipients successfully tapered IS with intact allograft function. The most common reason for IS discontinuity was pneumonia. Univariate analysis identified 15 clinical factors associated with tolerance achievement, including age at LT, follow-up time, preoperative total bilirubin, creatinine, INR, CYP polymorphism, types of transplantation, massive postoperative ascites, episodes of acute rejection, and the severity of EBV and CMV infection. Using multivariable Logistic regression, the authors established the predictive ITPLT model for post-LT tolerance, which included seven easily accessible clinical factors (age at LT, CYP3A5 genotype, types of transplantation, post-LT massive ascites, preoperative INR, creatinine, and total bilirubin levels). Then, the authors visualized the model using nomogram. The c-statistics for predicting tolerance achievement in the training, internal validation, and external validation cohorts were 0.854, 0.787, and 0.746, respectively.

Conclusion:

Multiple pre-LT and post-LT clinical factors affected the process of immune remodeling after pediatric LT. The predictive ITPLT model, composed of seven easily accessible clinical factors, could comprehensively reveal the effect of these clinical parameters on immune remodeling and accurately identify tolerant recipients after pediatric LT. The application of ITPLT could facilitate the individualized IS strategy in the future.

Mechanisms of the ascites volume differences between patients receiving a left or right hemi-liver graft liver transplantation: From biofluidic analysis

BACKGROUND AND OBJECTIVE

Post-transplant refractory ascites (RA) is common in patients receiving living donor liver transplantation (LDLT) using a left hemi-liver graft than in those using a right hemi-liver graft. However, there is currently no clear mechanism explaining the effect of grafts on ascites drainage. The purpose of this study is to analyze the values of blood flow parameters in the portal vein under different grafts using computational fluid dynamics (CFD) to interpret the relationship between portal pressure values with ascites drainage.

METHODS

In this work, ascites drainage was counted in 30 patients who underwent left-sided liver transplantation and 26 patients who underwent right-sided liver transplantation. The portal vein flow models of the transplanted liver under different flow rates were established based on computed tomography (CT) images and finite element theory. Ascites drainage and blood flow parameters were qualitatively compared.

RESULTS

The results show that the ascites drained from patients who received LDLT with a left hemi-liver is three times as that with a right hemi-liver. The simulation results show that the coefficient of the pressure-velocity curve of the left-liver is 1.7 times of the right-liver under the same hydrodynamic conditions, which qualitatively agrees with the clinical data. Moreover, the streamline of the transplanted left liver shows more vortexes compared with the right liver, which is a major reason for the left liver's higher pressure value.

CONCLUSION

This clinical phenomenon is reproduced and comprehensively explained by the hemodynamic parameters of the portal vein. This work establishes the relationship between portal pressure values and floating water drainage, and offers a new way for physicians to predict postoperative risks intuitively.

Impact of Graft Quality and Fluid Overload on Postoperative Massive Ascites After Living Donor Liver Transplantation

After living donor liver transplantation, we encounter cases with massive ascites, which is difficult to manage. We analyzed the risk factors for massive ascites after living donor liver transplantation. The subjects were 100 adult recipients who underwent living donor liver transplantation at Kyoto University Hospital from 2013 to 2017. We retrospectively assessed patient, graft, operative factors, and percent fluid overload, which were defined as [(weight on the day - preoperative weight)/preoperative weight] × 100%. We defined the massive ascites group as having a14-day average ascites ≥ 2500 mL and the mild ascites group as having a 14-day average ascites < 2500 mL. Forty-seven patients were included in the massive group, and 53 patients were included in the mild group. There was no difference in short- and long-term survival. In multivariate analysis, the presence of preoperative ascites (P = .0008), 14-day average percent fluid overload ≥ 14.5% (P = .0095), graft-to-recipient weight ratio < 0.86 (P = .0253), and donors' age ≥ 47 years (P = .0466) were identified as independent risk factors for massive ascites after living donor liver transplantation. A liver graft with a small graft-to-recipient weight ratio or from an elderly donor, which may indicate poor graft quality, presence of preoperative ascites, and postoperative fluid overload were associated with massive ascites after living donor liver transplantation.

Risk Factors for Refractory Ascites After Living Donor Liver Transplant

OBJECTIVES

Refractory ascites after liver transplant commonly occurs in living donor liver transplant (LDLT). Refractory ascites is associated with postoperative complications and poor prognosis. This study sought to determine the risk factors of refractory ascites and discuss their perioperative management.

METHODS

A retrospective study of 122 living donor liver transplant recipients between 2008 and 2017 was performed to analyze the risk factors, incidence, and characteristics of refractory ascites. Refractory ascites post LDLT was defined as the production of ascites fluid >1000 mL/d on postoperative day 14 or required repeated drainage.

RESULTS

A total of 24 patients (19.6%) developed refractory ascites. The 1-year survival rate was significantly worse in the refractory ascites group compared with the nonrefractory ascites group (P < .001). In a univariate analysis, patients with refractory ascites had a higher Model for End-Stage Liver Disease (MELD) score, donor age, presence of left lobe graft, ascites at laparotomy, portal venous pressure just after surgery, cold ischemia time, and absence of hepatocellular carcinoma compared with patients without refractory ascites. Multivariate proportional regression analyses revealed that MELD score ≥20, left lobe graft, donor age 50 years or older, and ascites at laparotomy ≥350 mL were independently associated with refractory ascites. Postoperative complications, such as bleeding (P < .001), sepsis (P < .001), and bloodstream infection within 30 days after LDLT (P < .00), were significantly higher in the refractory ascites group.

CONCLUSION

Refractory ascites is associated with reduced 1-year survival and increased postoperative complications. Four factors including MELD score ≥20, donor age 50 years or older, presence of left graft, and ascites at laparotomy ≥350 mL were independent predictors for refractory ascites.

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.