Tsuyoshi Shimamura

Ex vivo hypothermic machine perfusion (HMP) is a strategy for controlling ischemia-reperfusion injury in donation after circulatory death (DCD) liver transplantation. The pH of blood increases with a decrease in temperature and water dissociation, leading to a decrease in [H⁺]. This study aimed to verify the optimal pH of HMP for DCD livers. Rat livers were retrieved 30 min post-cardiac arrest and subjected to 3-h cold storage (CS) in UW solution (CS group) or HMP with UW-gluconate solution (machine perfusion [MP] group) of pH 7.4 (original), 7.6, 7.8, and 8.0 (MP-pH 7.6, 7.8, 8.0 groups, respectively) at 7–10 °C. The livers were subjected to normothermic perfusion to simulate reperfusion after HMP. All HMP groups showed greater graft protection compared to the CS group due to the lower levels of liver enzymes in the former. The MP-pH 7.8 group showed significant protection, evidenced by bile production, diminished tissue injury, and reduced flavin mononucleotide leakage, and further analysis by scanning electron microscopy revealed a well-preserved structure of the mitochondrial cristae. Therefore, the optimum pH of 7.8 enhanced the protective effect of HMP by preserving the structure and function of the mitochondria, leading to reduced reperfusion injury in the DCD liver.

Warm ischemia-reperfusion injury is a prognostic factor for hepatectomy and liver transplantation. However, its underlying molecular mechanisms are unknown. This study aimed to elucidate these mechanisms and identify the predictive markers of post-reperfusion injury. Rats with normal livers were subjected to 70% hepatic warm ischemia for 15, 30, or 90 min, while those with steatotic livers were subjected to 70% hepatic warm ischemia for only 30 min. The liver and blood were sampled at the end of ischemia and 1, 6, and 24 h after reperfusion. The serum alanine aminotransferase (ALT) activity, Suzuki injury scores, and lipid peroxidation (LPO) products were evaluated. The ALT activity and Suzuki scores increased with ischemic duration and peaked at 1 and 6 h after reperfusion, respectively. Steatotic livers subjected to 30 min ischemia and normal livers subjected to 90 min ischemia showed comparable injury. A similar trend was observed for LPO products. Imaging mass spectrometry of normal livers revealed an increase in lysophosphatidylinositol (LPI (18:0)) and a concomitant decrease in phosphatidylinositol (PI (18:0/20:4)) in Zone 1 (central venous region) with increasing ischemic duration; they returned to their basal values after reperfusion. Similar changes were observed in steatotic livers. Hepatic warm ischemia time-dependent acceleration of PI (18:0/20:4) to LPI (18:0) conversion occurs initially in Zone 1 and is more pronounced in fatty livers. Thus, the LPI (18:0)/PI (18:0/20:4) ratio is a potential predictor of post-reperfusion injury.

Background/Purpose: We aimed to verify a recent theory that female donors reduced the risk of hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT).Methods: A total of 1118 recipients registered in the Japanese Liver Transplantation Society database were evaluated for HCC, of whom 446 received a graft from female donors (F‐D group) and 672 from male donors (M‐D group).Results: Between the groups, donor age, recipient age and sex, positivity of hepatitis viruses, and graft type were different, whereas tumor‐related factors were all comparable. The 5‐year overall recurrence rates were 14% and 16% in the F‐D and M‐D groups, respectively (P = 0.59). The 5‐year graft recurrence rate was also comparable between the groups (4% and 6%, respectively, P = 0.17). Neither univariate nor multivariate analysis identified donor sex as a significant risk factor for recurrence. Propensity score matching showed similar 5‐year overall recurrence rates (15% in the F‐D group and 14% in the M‐D group, P = 0.63) and graft recurrence rates (5% and 5%, respectively, P = 0.94) between the groups.Conclusion: Donor sex did not affect post‐LT recurrence of HCC in the Japanese cohort and should not be considered in the process of donor selection or organ allocation.

Hepatocellular carcinoma (HCC) is the third highest cause of cancer-related mortality, and liver transplantation is the ideal treatment for this disease. The Milan criteria provided the opportunity for HCC patients to undergo LT with favorable outcomes and have been the international gold standard and benchmark. With the accumulation of data, however, the Milan criteria are not regarded as too restrictive. After the implementation of the Milan criteria, many extended criteria have been proposed, which increases the limitations regarding the morphological tumor burden, and incorporates the tumor’s biological behavior using surrogate markers. The paradigm for the patient selection for LT appears to be shifting from morphologic criteria to a combination of biologic, histologic, and morphologic criteria, and to the establishment of a model for predicting post-transplant recurrence and outcomes. This review article aims to characterize the various patient selection criteria for LT, with reference to several surrogate markers for the biological behavior of HCC (e.g., AFP, PIVKA-II, NLR, 18F-FDG PET/CT, liquid biopsy), and the response to locoregional therapy. Furthermore, the allocation rules in each country and the present evidence on the role of down-staging large tumors are addressed.

Background: Approximately 8300 hemophiliacs are registered in Japan, but no comprehensive reports on hepatobiliary and pancreatic surgery (HBPS) have been conducted. This report investigates the current status of HPBS in hemophilia patients in Japan.Methods: The subjects were hemophiliac patients seen between January 1 2007, and December 31 2017, at facilities participating in this study among the facilities for performing high‐difficulty cases nationwide designated by the Japanese Society for HBPS. A retrospective examination of short‐term outcomes in 49 cases was conducted to assess patient background, disease, surgical procedure, and complications.Results: The types of hemophilia were A: 43 cases, B: four cases, and von Willebrand disease: two cases (hemophilia severity: mild 32, moderate seven, severe 10). The target malignant diseases for surgery were hepatocellular carcinoma (HCC) in 20 cases, intrahepatic cholangiocellular carcinoma (CCC) in four cases, combined HCC‐CCC in two cases, hilar CCC in two cases, and pancreatic cancer in four cases. As for the surgical procedure, limited resection (subsegmentectomy and partial hepatectomy) was performed in 16 cases of HCC even with normal liver function tests. Pancreaticoduodenectomy and distal pacreatectomy were performed for pancreatic cancers as in the standard procedure. Postoperative complications were postoperative bleeding in two cases after hepatectomy and one after pancreatectomy in one case. When compared with Japanese National Clinical Data base, the complication rates after hepatectomy and pancreatectomy were not conspicuous in hemophilic patients.Conclusions: As long as they are performed in qualified centers, complication rate is not increased in hemophilic patients undergoing HBPS.

Cold preservation in University of Wisconsin (UW) solution is not enough to maintain the viability of the small intestine, due to the oxidative stress. The novel phenolic antioxidant 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA) has dual properties to reduce oxidative stress, radical scavenging, and antioxidant protein induction, in other cells. This study was designed to determine whether DHMBA reduces cold preservation injury of enterocytes, and to identify the effector site. Enterocytes were subjected to 48-h cold preservation under atmosphere in UW solution (±DHMBA), and then returned to normal culture to replicate reperfusion of the small intestine after cold preservation. At the end of cold preservation (ECP) and at 1, 3, 6, and 72 h after rewarming (R1h, R3h, R6h, and R72h), we evaluated cell function and the injury mechanism. The results showed that DHMBA protected mitochondrial function mainly during cold preservation, and suppressed cell death after rewarming, as shown by the MTT, ATP, mitochondrial membrane potential, LDH, and lipid peroxidation assays, together with enhanced survival signals (PI3K, Akt, p70S6K) and induction of antioxidant proteins (HO-1, NQO-1, TRX-1). We found that DHMBA mitigates the cold-induced injury of enterocytes by protecting the mitochondria through direct and indirect antioxidative activities.

Background: Intrahepatic cholangiocarcinoma had been considered a contraindication for liver transplantation because of poorer outcomes. However, incidental intrahepatic cholangiocarcinoma in the explanted liver has been reported because of the difficulty of obtaining an accurate diagnosis in cirrhotic livers on preoperative imaging.Methods: We conducted a nationwide survey to analyze the incidence of incidental intrahepatic cholangiocarcinoma and outcomes after liver transplantation, in Japan.Results: Forty‐five of 64 institutions (70%) responded to our initial investigation. Between January 2001 and December 2015, 6627 liver transplantations were performed in these 45 institutions, with 19 cases (0.3%) of incidental intrahepatic cholangiocarcinoma reported from 12 transplant centers. Six cases were diagnosed as hepatocellular carcinoma preoperatively. The 1‐, 3‐, and 5‐year recurrence‐free survival rates were 79%, 45%, and 45%, respectively. Tumor recurrence after liver transplantation was found in 10 patients (53%). The 1‐, 3‐, and 5‐year overall survival rates were 79%, 63%, and 46%, respectively.Conclusions: Intrahepatic cholangiocarcinoma at liver transplantation is associated with a high risk of recurrence and poor prognosis, even these tumors are detected incidentally in the explanted liver.