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Introduction: The Rhesus monkey (RM) is an excellent preclinical model in kidney, heart and islet transplantation that has provided the basis for new immunosuppressive protocols for clinical studies. However, there remain relatively few liver transplantation (LT) models in nonhuman primates. In this study, we analyzed the immune cell populations of PBMCs and secondary lymphoid organs along with livers of normal rhesus monkeys and compared them to those of rejecting liver transplanted recipient's following withdrawal of immunosuppression. Methods & Results: We undertook five allogeneic ABO compatible orthotopic LT in monkeys using five normal donor monkey livers. We collected tissues including lymph nodes, spleens, blood, recipient livers and performed flow cytometric analysis using isolated immune cells. We found that CD4 or CD8 naive T cells were normally seen at low levels and memory T cells were seen at high levels in the liver rather than lymphoid organs or PBMC. However, regulatory cells such as CD4+FoxP-3(+)T cells and CD8+CD28- cells remained in high numbers in the liver, but not in lymph node or PBMC. The comparison of CD4/8 T sub-populations in normal and rejected livers and the various tissues showed that naive cells were dramatically decreased in spleen, lymph node and PBMC of rejected liver transplanted monkeys, but rather memory CD4/8 T cells were increased in all tissues and PBMC. Conclusion: The normal liver has large numbers of CD4 Tregs, CD8+CD28- and myeloid-derived suppressor cells, which are known immunosuppressive cells occurring at much higher levels than those seen in lymph node or peripheral blood. Memory T cells are dramatically increased in rejecting liver allografts of rhesus monkeys compared to those seen in normal RM tissues. This article is protected by copyright. All rights reserved.

Patients with large spontaneous splenorenal shunts (SRSs) prove challenging during liver transplantation (LT), regardless of organizing portal vein (PV) thrombosis. Here, we detail the clinical outcomes of 26 patients who underwent direct ligation of large SRSs during LT. Direct ligation of large SRS was applied in poor portal flow during LT. We performed temporary test clamping of the SRS before direct ligation and applied PV pressure monitoring in patients who showed signs of portal hypertension, such as bowel edema. We retrospectively reviewed and evaluated their clinical outcomes. Among 843 patients who underwent LT between 2010 and 2015, 26 (3.1%) underwent direct ligation of SRS without any intraoperative event. Mean preoperative Model for End-Stage Liver Disease score was 16.7 ± 9.0. The main PV diameter on preoperative computed tomography was 8.3 ± 3.4 mm (range, 3.0-14.0 mm). SRS was easily identified at just below the distal pancreas and beside the inferior mesenteric vein in all patients. Accompanying PV thrombectomy was done in 42.3% of patients. Among 26 patients, massive and prolonged ascites was evident in 15.4% (n = 4) postoperatively. They were all living donor LT recipients with a small PV diameter (4.0-6.7 mm). Except for 1 patient who underwent splenic artery embolization, ascites was tolerable and well controlled by conservative management. There was a 7.7% rate of major complications related to direct ligation, including reoperation due to combined ligation of SRS along with a left renal vein at the confluence. Except for 1 hospital mortality due to sepsis, 25 patients (96.2%) are alive with no evidence of further PV complications. In conclusion, direct ligation of large SRS during LT is a safe and feasible method to overcome the effects of a large SRS. Liver Transplantation 23 899-906 2017 AASLD.

The process of evaluating potential donors in liver transplantation is important to ensure donor safety and provide optimal recipient outcomes. However, there has been no report about donor exclusion rates and reasons for such exclusion in Korea. In this study, we aimed to elucidate the outcomes of potential living liver donor evaluation in a major living donor liver transplantation center. From July 2011 to June 2015, prospectively collected data of 726 potential donors for 588 matched recipients were subsequently evaluated. Among 726 potential donors, 374 potential donors (51.5%) finally reached donation; 352 potential donors (48.5%) were excluded for various reasons. Donor reasons were 29.8%, including medical problems, withdrawal of consent, graft volume issues, and identification of a better suitable donor. Recipient reasons were 20.7%, including recipient death or recovery, allocation to deceased donor, and progressions of hepatocellular carcinoma. A total of 38 (5.2%) potential donors had a fatty liver. Among them, 15 (39.5%) potential donors tried short-term weight reduction and eventually were able to donate. In conclusion, the main reasons for donor exclusion were medical problems and withdrawal of consent. Therefore, thorough medical screening and careful examination for donor voluntarism are important in the donor evaluation process. Liver Transplantation 23 614-624 2017 AASLD.