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Three‐dimensional (3D) printing has been used to support organ transplantations. However, whether it helps remains unclear. This study aimed to present and assess the application of 3D‐printed liver models in pediatric living donor liver transplantation (LDLT). The 3D images were printed to touchable liver models with transparent liver parenchyma, specifically colored hepatic vessels, and biliary structures. A total of 30 consecutive recipients were enrolled in the study: 10 were operated on with the support of 3D printing (3D‐printing group) and 20 (control group) were operated on without it. Detailed photographs and data of the cases in the 3D‐printing group were presented. One patient underwent auxiliary partial orthotopic liver transplantation using the left lobe graft, in which the abdominal cavity model was also printed to test whether the planned graft fit the recipient’s abdominal cavity. The 3D‐printed models facilitated surgical planning and procedures, particularly in the management of hepatic veins and in the prevention of large‐for‐size syndrome. The operative time of donors in the 3D‐printing group was significantly shorter compared with the control group (2.3 ± 0.4 versus 3.0 ± 0.4 hours; P < 0.001). Inpatient costs for donors in the 3D‐printing group were 17.1% lower than those in the control group (34.6 ± 6.6 versus 41.7 ± 10.4 thousand ¥; P = 0.03). In conclusion, in small infants and complicated pediatric LDLT patients, 3D‐printed models can help minimize the risk of large‐for‐size syndrome and graft reduction. The 3D‐printed models may be conducive to liver graft procurement and intraoperative assistance in pediatric LDLT.

In the early December 2019, a novel coronavirus named severe acute respiratory syndrome coronavirus 2 was first reported in Wuhan, China, followed by an outbreak that spread around the world. Numerous studies have shown that liver injury is common in patients with coronavirus disease 2019 (COVID-19), and may aggravate the severity of the disease. However, the exact cause and specific mechanism of COVID-associated liver injury needs to be elucidated further. In this review, we present an analysis of the clinical features, potential mechanisms, and treatment strategies for liver injury associated with COVID-19. We hope that this review would benefit clinicians in devising better strategies for management of such patients.

Although salvage liver transplantation (LT) has been widely adopted as a treatment for recurrent hepatocellular carcinoma(HCC), candidate selection criteria have not been established. This single-center study aimed to identify risk factors associated with HCC recurrence and survival following salvage LT. The study included 74 patients treated with salvage LT between October 2001 and February 2013. The median follow-up was 37.2 months after LT. There were 29 cases of HCC recurrence and 31 deaths following LT. Microvascular invasion at the time of liver resection, a time interval to post-LR HCC recurrence of ≤ 12months, an alpha-fetoprotein level at LT greater than 200 ng/mL, and having undergone LT outside of the UCSF criteria were independent risk factors for HCC recurrence after salvage LT. Patients with no more than one risk factor had a 5-year recurrence-free survival rate of 71.2% compared to 15.9% in patients with two or more risk factors. These findings suggest that to avoid post-LT HCC recurrence and a dismal prognosis, patients with no more than one risk factor for recurrence should be given priority for salvage LT. These criteria may improve the outcomes of patients treated with salvage LT and facilitate the effective use of limited organ supplies.

Liver transplantation is the ideal treatment approach for a variety of end-stage liver diseases. However, lifelong , systemic immunosuppressive treatment after transplantation is required to prevent rejection and graft loss, which is associated with severe side effects, although liver allograft is considered more tolerogenic. Therefore, understanding the mechanism underlying the unique immunologically privileged liver organ is valuable for transplantation management and autoimmune disease treatment. The unique hepatic acinus anatomy and a complex cellular network constitute the immunosuppressive hepatic microenvironment, which are responsible for the tolerogenic properties of the liver. The hepatic microenvironment contains a variety of hepatic-resident immobile non-professional antigen-presenting cells, including hepatocytes, liver sinusoidal endothelial cells, Kupffer cells, and hepatic stellate cells, that are insufficient to optimally prime T cells locally and lead to the removal of alloreactive T cells due to the low expression of major histocompatibility complex (MHC) molecules, costimulatory molecules and proinflammatory cytokines but a rather high expression of coinhibitory molecules and anti-inflammatory cytokines. Hepatic dendritic cells (DCs) are generally immature and less immunogenic than splenic DCs and are also ineffective in priming naïve allogeneic T cells via the direct recognition pathway in recipient secondary lymphoid organs. Although natural killer cells and natural killer T cells are reportedly associated with liver tolerance, their roles in liver transplantation are multifaceted and need to be further clarified. Under these circumstances, T cells are prone to clonal deletion, clonal anergy and exhaustion, eventually leading to tolerance. Other proposed liver tolerance mechanisms, such as soluble donor MHC class I molecules, passenger leukocytes theory and a high-load antigen effect, have also been addressed. We herein comprehensively review the current evidence implicating the tolerogenic properties of diverse liver cells in liver transplantation tolerance.

BackgroundLiver transplantation (LT) is considered the standard treatment for end-stage liver disease, but ideal donors remain in limited supply, resulting in an unavoidable increase in the need to use grafts from marginal donors. The attenuation of ischemia-reperfusion injury (IRI) in such marginal donors is therefore crucial for reducing the possibility of the primary non-function of grafts and graft loss. Some reports have found that molecular-hydrogen showed antioxidant and anti-inflammatory effects in preventing IRI in some non-hepatic transplant models. Therefore, we investigated whether or not molecular-hydrogen could attenuate IRI in LT model rats.MethodsWe used a hydrogen-rich water bath to dissolve hydrogen into solution and graft tissues and performed isogenic and orthotopic LT in Lewis rats with University of Wisconsin (UW) solution. Blood and tissue samples were collected 6 h after the reperfusion. Hepatic enzymes in serum were measured. Pathological findings including the expressions of cytokines and heme oxygenase (HO)-1 in liver tissues were evaluated.ResultsThe concentration of hydrogen inside the graft tissues increased depending on the storage time, plateauing after 1 h. Serum liver enzyme levels were significantly lower and the histology score of liver damage markedly attenuated in the group given grafts preserved in hydrogen-rich UW solution than in the control group. The hydrogen-rich UW solution group also showed less oxidative damage and hepatocyte apoptosis than the control group, and the expression of proinflammatory cytokines tended to be lower while the protein levels of HO-1 were significantly increased (n = 3–12 per group, P < 0.05).ConclusionsStorage of liver grafts in hydrogen-rich UW solution resulted in superior functional and morphologic protection against IRI via the up-regulation of HO-1 expression.Electronic supplementary materialThe online version of this article (10.1186/s12876-019-0939-7) contains supplementary material, which is available to authorized users.

Background. Supercooling preservation techniques store a donor organ below 0°C without freezing. This has great advantages in inhibiting metabolism and preserving the organ in comparison to conventional preservation at 4°C. We developed a novel supercooling technique using a liquid cooling apparatus and novel preservation and perfusion solutions. The purpose of this study was to evaluate the preservation effect of our supercooling preservation technique in a mouse heart transplantation model. Methods. Syngeneic heterotopic heart transplantation was performed in 3 groups of mice: (1) the nonpreservation group, in which the cardiac grafts were transplanted immediately after retrieval; (2) the conventional University of Wisconsin (UW) group, in which the cardiac grafts were stored in UW solution at 4°C for different periods of time; and (3) the supercooling group, in which the cardiac grafts were stored in a novel supercooling preservation solution at –8°C for different periods of time. The maximal preservation time was investigated. Twenty-four-hour sample data were collected and analyzed to compare supercooling preservation to conventional UW preservation. Results. Our technique yielded a stable –8°C supercooling state. Cardiac graft revival was successfully achieved after supercooling preservation for 144 hours, and long-term survival was observed after supercooling preservation for 96 hours. Posttransplant outcomes, including myocardial ischemia–reperfusion injury, oxidative stress-related damage, and myocardial cell apoptosis, were improved in comparison to conventional 4°C UW preservation. Conclusions. Supercooling heart preservation at –8°C greatly prolonged the preservation time and improved the posttransplant outcomes in comparison to conventional 4°C UW preservation. Supercooling preservation is a promising technique for organ preservation.

Background: Liver transplantation (LT) is considered the standard treatment for end-stage liver disease, but ideal donors remain in limited supply, resulting in an unavoidable increase in the need to use grafts from marginal donors. The attenuation of ischemia-reperfusion injury (IRI) in such marginal donors is therefore crucial for reducing the possibility of the primary non-function of grafts and graft loss. Some reports have found that molecularhydrogen showed antioxidant and anti-inflammatory effects in preventing IRI in some non-hepatic transplant models. Therefore, we investigated whether or not molecular-hydrogen could attenuate IRI in LT model rats. Methods: We used a hydrogen-rich water bath to dissolve hydrogen into solution and graft tissues and performed isogenic and orthotopic LT in Lewis rats with University of Wisconsin (UW) solution. Blood and tissue samples were collected 6 h after the reperfusion. Hepatic enzymes in serum were measured. Pathological findings including the expressions of cytokines and heme oxygenase (HO)-1 in liver tissues were evaluated. Results:The concentration of hydrogen inside the graft tissues increased depending on the storage time, plateauing after 1 h. Serum liver enzyme levels were significantly lower and the histology score of liver damage markedly attenuated in the group given grafts preserved in hydrogen-rich UW solution than in the control group. The hydrogen-rich UW solution group also showed less oxidative damage and hepatocyte apoptosis than the control group, and the expression of proinflammatory cytokines tended to be lower while the protein levels of HO-1 were significantly increased (n = 3-12 per group, P < 0.05).Conclusions: Storage of liver grafts in hydrogen-rich UW solution resulted in superior functional and morphologic protection against IRI via the up-regulation of HO-1 expression.