A new method to predict venous complications in pediatric liver transplantation: Evaluation of splenic parameters by ultrasonography.

BACKGROUND: Venous complications after pediatric liver transplantation seriously affect the survival rate of patients and grafts. At present, the diagnostic indicators have not been unified. Venous complications may cause portal hypertension, which may lead to splenomegaly and splenic vein dilatation. Therefore, the changes in spleen may be closely related to the venous complications. The purpose of this study was to explore the relationship between ultrasonic splenic parameters and venous complications and to study whether these splenic parameters can be used for the diagnosis of venous complications. METHODS: We retrospectively included pediatric patients who underwent liver transplantation and collected ultrasonic spleen parameters before, and then 1-3 days, 1-3 weeks, 1-3 months, and 4-12 months after liver transplantation. We observed whether there were portal vein or hepatic vein complications within 1 year after liver transplantation. RESULTS: Among 109 pediatric patients after liver transplantation included in our study, 11 of them suffered from portal vein complications and nine hepatic vein complications. Spleen transverse diameter, spleen longitudinal diameter, spleen portal vein diameter, spleen index, spleen transverse diameter ratio, spleen longitudinal diameter ratio, and spleen index ratio were independent risk factors of venous complications. The accuracy of spleen transverse diameter (AUROC: 0.73), spleen index (AUROC: 0.70), spleen transverse diameter ratio (AUROC: 0.71), and spleen index ratio (AUROC: 0.72) in predicting venous complications were higher than other ones. CONCLUSIONS: Ultrasonic examination is a common follow-up method for pediatric patients after liver transplantation and the application of ultrasonic spleen parameters may be helpful to monitor venous complications.

Is Marginal Donor an Efficient Solution for Expanding the Donor Pool for Liver Transplant?

Once the techniques of hepatobiliopancreatic surgery improved, liver transplantation widely extended in different hospitals; therefore, the need of grafts and automatically of liver donors reported a significant increase in the last decade. In this respect, attention was focused on increasing the liver donor pool. The aim of this review is to study the benefits of using marginal grafts in liver transplantation. With the advent of multiple methods of liver preservation, the use of grafts previously considered unsuitable has become possible. Thus, extended allocation criteria have emerged. However, the allocation of these grafts must be carefully considered and analyzed in the context of both recipient and donor factors.

Heterotopic Auxiliary Whole Liver Rat Transplant Model Utilizing a Hepaticoureterostomy for Allograft Rejection Studies.

Small animal transplant models are indispensable for organ tolerance studies investigating feasible therapeutic interventions in preclinical studies. Rat liver transplantation (LTx) protocols typically use an orthotopic model where the recipients' native liver is removed and replaced with a donor liver. This technically demanding surgical procedure requires advanced micro-surgical skills and is further complicated by lengthy anhepatic and lower body ischemia times. This prompted the development of a less complicated heterotopic method that can be performed faster with no anhepatic or lower body ischemia time, reducing post-surgery stress for the recipient animal. This heterotopic LTx protocol includes two main steps: excising the liver from the donor rat and transplanting the whole liver into the recipient rat. During the excision of the donor liver, the surgeon ligates the supra-hepatic vena cava (SHVC) and hepatic artery (HA). On the recipient side, the surgeon removes the left kidney and positions the donor liver with the portal vein (PV), infra-hepatic vena cava (IHVC), and bile duct facing the renal vessels. Further, the surgeon anastomoses the recipient's renal vein end to end with the IHVC of the liver and arterializes the PV with the renal artery using a stent. A hepaticoureterostomy is utilized for biliary drainage by anastomosing the bile duct to the recipient's ureter, permitting the discharge of bile via the bladder. The average duration of the transplantation was 130 min, cold ischemia duration was around 35 min, and warm ischemia duration was less than 25 min. Hematoxylin and eosin histology of the auxiliary liver from syngeneic transplants showed normal hepatocyte structure with no significant parenchymal alterations 30 days post-transplant. In contrast, 8-day post-transplant allogeneic graft specimens demonstrated extensive lymphocytic infiltration with a Banff Schema rejection activity index score of 9. Therefore, this LTx method facilitates a low morbidity rejection model alternative to orthotopic LTx.

Twelve-hour normothermic liver perfusion in a rat model: characterization of the changes in the ex-situ bio-molecular phenotype and metabolism.

The partial understanding of the biological events that occur during normothermic machine perfusion (NMP) and particularly during prolonged perfusion might hinder its deployment in clinical transplantation. The aim of our study was to implement a rat model of prolonged NMP to characterize the bio-molecular phenotype and metabolism of the perfused organs. Livers (n = 5/group) were procured and underwent 4 h (NMP4h) or 12 h (NMP12h) NMP, respectively, using a perfusion fluid supplemented with an acellular oxygen carrier. Organs that were not exposed to any procedure served as controls (Native). All perfused organs met clinically derived viability criteria at the end of NMP. Factors related to stress-response and survival were increased after prolonged perfusion. No signs of oxidative damage were detected in both NMP groups. Evaluation of metabolite profiles showed preserved mitochondrial function, activation of Cori cycle, induction of lipolysis, acetogenesis and ketogenesis in livers exposed to 12 h-NMP. Increased concentrations of metabolites involved in glycogen synthesis, glucuronidation, bile acid conjugation, and antioxidant response were likewise observed. In conclusion, our NMP12h model was able to sustain liver viability and function, thereby deeply changing cell homeostasis to maintain a newly developed equilibrium. Our findings provide valuable information for the implementation of optimized protocols for prolonged NMP.

Anastomosis selection in liver transplantation for recipients with unusable recipient hepatic arteries: a bayesian network meta-analysis.

BACKGROUND: The anastomosis of donor and recipient hepatic arteries is standard in liver transplantations. For transplant recipients with unusable hepatic arteries, appropriate artery selection should be conducted using evidence-based considerations; therefore, this network meta-analysis (NMA) aimed to analyze the most suitable alternative recipient artery for anastomosis during liver transplantations. METHODS: Comprehensive searches of the Scopus, Cochrane Library, and MEDLINE databases were conducted to analyze observational studies containing non-standard anastomoses in liver transplantations that used the splenic artery, aorta, celiac, or branches of the gastric artery. The outcome parameters included intraoperative components, complications, and survival data. This NMA used the BUGSnet package in R studio and the results were presented in a Forest plot, league table, and SUCRA plot. RESULTS: Among the 13 studies included in this NMA, 5 arteries were used for the anastomoses. The splenic artery anastomosis showed a high risk of thrombosis and a low risk of stenosis (OR 1.12, 95% CI 0.13-3.14) and biliary tract abnormalities (OR 0.79, 95% CI 0.36-1.55). In addition, the graft survival (OR 1.08; 95% CI 0.96-1.23) and overall survival (1-year survival OR 1.09, 95% CI 0.94-1.26; 5-year survival OR 1.95% CI 0.83-1.22) showed favorable results using this artery. Constraints to the use of the splenic artery were longer operation and cold ischemic times. However, the duration of hospital stay (MD 1.36, 95% CI -7.47 to 10.8) was shorter than that when the other arteries were used, and the need for blood transfusions was minimal (MD -1.74, 95% CI -10.2 to 6.7). CONCLUSION: In recipients with unusable hepatic arteries, the splenic artery of the patient should be the first consideration for anastomosis selection in liver transplantations.

Research progress on anatomy reconstruction of rat orthotopic liver transplantation.

Rat orthotopic liver transplantation (ROLT) serves as an ideal animal model and has gained popularity in addressing complications and perioperative treatments related to clinical liver transplantation. Through extensive research on ROLT model construction, the conventional "two-cuff" method has gradually become established. However, traditional methods still present challenges including limited visual field during vascular suturing, vascular torsion, biliary tract injuries, and prolonged anhepatic periods. Consequently, this paper aims to review the latest advancements and various techniques in this field, providing a valuable reference for individuals interested in constructing ROLT models.

[Clinical application of split liver transplantation: a single center report of 203 cases].

Objective: To investigate the safety and therapeutic effect of split liver transplantation (SLT) in clinical application. Methods: This is a retrospective case-series study. The clinical data of 203 consecutive SLT, 79 living donor liver transplantation (LDLT) and 1 298 whole liver transplantation (WLT) performed at the Third Affiliated Hospital of Sun Yat-sen University from July 2014 to July 2023 were retrospectively analyzed. Two hundred and three SLT liver grafts were obtained from 109 donors. One hundred and twenty-seven grafts were generated by in vitro splitting and 76 grafts were generated by in vivo splitting. There were 90 adult recipients and 113 pediatric recipients. According to time, SLT patients were divided into two groups: the early SLT group (40 cases, from July 2014 to December 2017) and the mature SLT technology group (163 cases, from January 2018 to July 2023). The survival of each group was analyzed and the main factors affecting the survival rate of SLT were analyzed. The Kaplan-Meier method and Log-rank test were used for survival analysis. Results: The cumulative survival rates at 1-, 3-, and 5-year were 74.58%, 71.47%, and 71.47% in the early SLT group, and 88.03%, 87.23%, and 87.23% in the mature SLT group, respectively. Survival rates in the mature SLT group were significantly higher than those in the early SLT group (χ2=5.560,P=0.018). The cumulative survival rates at 1-, 3- and 5-year were 93.41%, 93.41%, 89.95% in the LDLT group and 87.38%, 81.98%, 77.04% in the WLT group, respectively. There was no significant difference among the mature SLT group, the LDLT group and the WLT group (χ2=4.016, P=0.134). Abdominal hemorrhage, infection, primary liver graft nonfunction,and portal vein thrombosis were the main causes of early postoperative death. Conclusion: SLT can achieve results comparable to those of WLT and LDLT in mature technology liver transplant centers, but it needs to go through a certain time learning curve.

Real-time monitoring of mitochondrial oxygenation during machine perfusion using resonance Raman spectroscopy predicts organ function.

Organ transplantation is a life-saving procedure affecting over 100,000 people on the transplant waitlist. Ischemia reperfusion injury (IRI) is a major challenge in the field as it can cause post-transplantation complications and limit the use of organs from extended criteria donors. Machine perfusion technology has the potential to mitigate IRI; however, it currently fails to achieve its full potential due to a lack of highly sensitive and specific assays to assess organ quality during perfusion. We developed a real-time and non-invasive method of assessing organs during perfusion based on mitochondrial function and injury using resonance Raman spectroscopy. It uses a 441 nm laser and a high-resolution spectrometer to quantify the oxidation state of mitochondrial cytochromes during perfusion. This index of mitochondrial oxidation, or 3RMR, was used to understand differences in mitochondrial recovery of cold ischemic rodent livers during machine perfusion at normothermic temperatures with an acellular versus cellular perfusate. Measurement of the mitochondrial oxidation revealed that there was no difference in 3RMR of fresh livers as a function of normothermic perfusion when comparing acellular versus cellular-based perfusates. However, following 24 h of static cold storage, 3RMR returned to baseline faster with a cellular-based perfusate, yet 3RMR progressively increased during perfusion, indicating injury may develop over time. Thus, this study emphasizes the need for further refinement of a reoxygenation strategy during normothermic machine perfusion that considers cold ischemia durations, gradual recovery/rewarming, and risk of hemolysis.

Small-for-size syndrome in a 9.7 kg pediatric recipient with a whole liver graft.

BACKGROUND: Small-for-size syndrome (SFSS) in pediatric liver transplant recipients, particularly those weighing less than 10 kg, is rare. This report describes a case of a 15-month-old whole liver transplant recipient who suffered SFSS, and systematic literature review was performed to identify outcomes of such cases and potential risk factors for SFSS. CASE PRESENTATION: A 15-month-old toddler with a history of biliary atresia underwent a deceased donor whole liver transplant. The graft weighed 160 g, resulting in a graft-to-recipient weight ratio (GRWR) of 1.6%. The post-operative course was complicated by SFSS, characterized by massive ascites causing hemodynamic instability and compromised hepatic artery flow. Pharmacological intervention with octreotide was initiated, and the patient eventually recovered. CONCLUSION: In small pediatric recipients, especially those weighing less than 10 kg, the native liver body weight ratio (LBWR) is significantly higher. When selecting an appropriately sized graft for these recipients, this higher ratio should be taken into consideration. The literature review suggests that a GRWR of less than 2% is associated with a higher incidence of small-for-size syndrome in small pediatric recipients weighing less than 10 kg.

A Retrospective Study of Long-Term Outcomes in 16 ABO-Incompatible Deceased Donor Pediatric Liver Transplants from a National Transplant Center at Helsinki University Hospital, Finland, 1987-2022.

BACKGROUND The use of ABO-incompatible liver transplants (ABO-ILTs) from deceased donors has become more common due to the shortage of available donor livers and increased transplant waiting times. This retrospective study from a national transplant center at Helsinki University Hospital, Finland, aimed to assess the long-term outcomes of ABO-incompatible deceased donor pediatric liver transplants between 1987 and 2022. MATERIAL AND METHODS Sixteen (9.5%) of the 169 pediatric liver transplantations were ABO-ILTs. The median age at transplantation was 5.0 (0.5-15.4) years. Reasons for ABO-ILTs were acute liver failure (18.75%), malignancy (12.5%), small body size and long waiting time (25%), and other reasons (43.75%). The median post-transplant follow-up time was 147 (0.72-353) months. Patient and graft survival and occurrence of surgical complications were compared to ABO-identical transplants, and anti-ABO antibody titers were analyzed. RESULTS The 1-, 3-, and 5-year patient survivals were comparable between the ABO-I and ABO-compatible groups, being 81.3%, 73.9%, and 73.9% (ABO-I) and 87.5%, 82.5%, 77.9% (ABO-compatible), respectively. Three patients with ABO-ILTs died of sepsis and multiorgan failure during the first 3 months after transplantation. The occurrence of biliary complications and early vascular thrombosis (<30 days after transplantation) did not differ significantly between recipients with an ABO-ILT vs ABO-compatible liver graft. CONCLUSIONS The findings from this study support findings from previous studies that outcomes after ABO-incompatible liver transplants in children were comparable to outcomes from ABO-identical liver transplants.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation.

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Bacterial Infections After Liver Transplantation and the Role of Oral Selective Digestive Decontamination: A Retrospective Cohort Study.

BACKGROUND: Bacterial infections are common after liver transplantation (LT) and cause serious morbidity and mortality. In our center, prolonged selective digestive decontamination (SDD) is the standard of care, which may lead to a reduced number and severity of bacterial infections. The aim of the current study was to investigate bacterial infection rates, the causative pathogens, localization, and the possible influence of SDD within the first year after LT. METHODS: A retrospective single-center cohort study was performed. Patients within their first year after LT between 2012 and 2017 were included. Patients received SDD for 3 weeks immediately after LT. The type of infection, bacterial subtype, CSI classification, severity, and potential interventions were recorded. RESULTS: One hundred eighty-six patients were included in the study. Seventy-eight patients (41.9%) had a bacterial infection within the first year after LT. The most common types of infection were cholangitis (25.8%) and secondary infected abdominal fluid collections (25.3%). The most common bacteria were Gram-positive enterococcal- (36.5%) and Gram-negative enterobacterial species (34.2%). 35.5% of the infections occurred within the first month after LT, mainly caused by Gram-positive bacteria (76.7%). CONCLUSIONS: Cholangitis and infected abdominal fluid are the most common types of infection within one year after LT, mainly caused by enterococcal- and enterobacterial species. Within the first month after LT, infections were mostly caused by Gram-positive bacteria, which could be a consequence of protocol use of SDD. The results can be used for the choice of empirical antibiotic therapy based on the most common types of bacteria and the time frame after LT.

Size Matching Deceased Donor Livers: The Tampa General Measurement System.

BACKGROUND: No reliable or standardized system exists for measuring the size of deceased donor livers to determine whether they will fit appropriately into intended recipients. METHODS: This retrospective, single-center study evaluated the efficacy of Tampa General Hospital's size-matching protocol for consecutive, deceased donor liver transplantations between October 2021 and November 2022. Our protocol uses cross-sectional imaging at the time of organ offer to compare the donor's right hepatic lobe size with the recipient's right hepatic fossa. Outcomes were analyzed, including large-for-size syndrome, small-for-size syndrome, early allograft dysfunction, primary nonfunction, graft survival, and patient survival. RESULTS: We included 171 patients in the study. The donor liver physically fit in all the patients except one whose pretransplant imaging was outdated. One patient (0.6%) had large-for-size syndrome, none had small-for-size syndrome, 15 (10%) had early allograft dysfunction, and none had primary nonfunction. There were 11 (7%) patient deaths and 11 (7%) graft failures. CONCLUSION: Our measurement system is fast and effective. It reliably predicts whether the donor liver will fit in the intended recipient and is associated with low rates of early allograft dysfunction.

Optimización de los resultados del programa de bipartición hepática para trasplante split / Liver bipartition program for «SPLIT» transplantation: Optimization results

Introducción: El trasplante hepático (TH) split es un procedimiento extendido por toda Europa. En 2018 en Cataluña, se redefinió la distribución de donantes, siendo candidatos potenciales para split todos aquellos menores de 35 años y se flexibilizó la selección del adulto para el injerto derecho. El objetivo del estudio es evaluar el efecto de estas modificaciones en la utilización de donantes para split, en las listas de espera (LE) y en los resultados de los adultos que recibieron un injerto split. Métodos: Estudio observacional y retrospectivo; dos periodos de recogida de datos «pre» (2013-2017) y «post» (2018-2021). Los resultados de los receptores adultos se analizaron mediante un propensity score matching. Resultados: En el primer periodo fueron registrados tres donantes y se trasplantaron tres pacientes pediátricos y dos adultos; en el periodo post se obtuvieron 24 donantes, realizándose el trasplante en 19 adultos y 24 receptores infantiles. Al comparar las LE se evidenció una disminución significativa tanto en la de adultos (p = 0,0001) como en la infantil (p = 0,0004) y hasta en tres ocasiones no hubo receptores en la LE infantil. No se observaron diferencias significativas en cuanto a morbilidad o mortalidad, ni en la supervivencia global en el grupo de receptores adultos de injertos split. Conclusiones: La flexibilidad en la selección del receptor adulto y la nueva distribución de donantes ayuda a aumentar la tasa de bipartición, permitiendo reducir la LE pediátrica sin afectar los resultados en los trasplantados adultos ni su estancia en LE.(AU)

Introduction: SPLIT liver transplantation is a procedure performed throughout Europe. In 2018 in Catalonia, the distribution of donors was redefined, being potential candidates for SPLIT all those under 35 years and it was made flexible the adult selection for the right graft. The study aim is to evaluate the effect of this modification on the use of SPLIT donors on the adult/pediatric waiting lists, as well as to evaluate the post-transplant results of adults who received a SPLIT donor. Methods: Observational and retrospective study; 2 data collection periods «PRE» (2013–2017) and «POST» (2018–2021). The adults recipients results were analyzed by a propensity score matching. Results: In the first period, three donors were registered and three pediatric patients and two adults received a transplant. In the POST period, 24 donations with liver bipartition were made, performing the transplant in 19 adults and 24 children. When comparing the adults waiting lists, a significant decrease was evidenced, both for adults (p = 0.0001) and on the children's waiting list (p = 0.0004), and up to three times there were no recipients on the pediatric waiting list. No significant differences between hospital morbidity or mortality or overall survival were observed in the group of adult recipients of SPLIT grafts. Conclusions: The flexibility in the selection of the adult recipient and the new distribution of donors makes possible to increase the bipartition rate, reducing the pediatric waiting list without worsening the adults results transplant recipients or their permanence on the waiting list.(AU)

Ferrostatin-1 improves prognosis and regulates gut microbiota of steatotic liver transplantation recipients in rats.

Aims: To investigate the effects of Ferrostatin-1 (Fer-1) on improving the prognosis of liver transplant recipients with steatotic liver grafts and regulating gut microbiota in rats. Methods: We obtained steatotic liver grafts and established a liver transplantation model. Recipients were divided into sham, liver transplantation and Fer-1 treatment groups, which were assessed 1 and 7 days after surgery (n = 6). Results & conclusion: Fer-1 promotes recovery of the histological structure and function of steatotic liver grafts and the intestinal tract, and improves inflammatory responses of recipients following liver transplantation. Fer-1 reduces gut microbiota pathogenicity, and lowers iron absorption and improves fat metabolism of recipients, thereby protecting steatotic liver grafts.

A contemporary analysis of 20,086 deceased donor liver biopsies.

BACKGROUND: Pre-transplant deceased donor liver biopsy may impact decision making; however, interpretation of the results remains variable and depends on accepting center practice patterns. METHODS: In this cohort study, adult recipients from 04/01/2015-12/31/2020 were identified using the UNOS STARfile data. The deceased donor liver biopsies were stratified by risk based on degree of fibrosis, macrovesicular fat content, and level of portal infiltration (low-risk: no fibrosis, no portal infiltrates, and <30% macrosteatosis; moderate-risk: some fibrosis or mild infiltrates and <30% macrosteatosis; high-risk: most fibrosis, moderate/marked infiltrates, or ≥30% macrosteatosis). Graft utilization, donor risk profile, and recipient outcomes were compared across groups. RESULTS: Of the 51,094 donor livers available, 20,086 (39.3%) were biopsied, and 34,606 (67.7%) were transplanted. Of the transplanted livers, 14,908 (43.1%) were biopsied. The transplanted grafts had lower mean macrovesicular fat content (9.3% transplanted vs. 26.9% non-transplanted, P < 0.001) and less often had any degree of fibrosis (20.9% vs. 39.9%, P < 0.001) or portal infiltration (51.3% vs. 58.2%, P < 0.001) versus non-transplanted grafts. Post-transplant recipient LOS (14.2 days high-risk vs. 15.2 days low-risk, P = 0.170) and 1-year graft survival (90.5% vs. 91.7%, P = 0.137) did not differ significantly between high- versus low-risk groups. Kaplan-Meier survival estimates further revealed no differences in the 5-year graft survival across risk strata (P = 0.833). Of the 5178 grafts biopsied and turned down, PSM revealed 1338 (26.0%) were potentially useable based on biopsy results and donor characteristics. CONCLUSION: Carefully matched deceased donor livers with some fibrosis, inflammation, or steatosis ≥30% may be suitable for transplantation. Further study of this group of grafts may decrease turndowns of potentially useable organs.

Achieving 400 Living Donor Liver Transplantations Annually During the COVID-19 Pandemic: A Single-Center Experience.

BACKGROUND: The COVID-19 pandemic has had a major impact on liver transplantation (LT) and living donor programs globally. PURPOSE: In this study, we aimed to present the principles and strategies of our LT program during the pandemic period and describe its achievements. BASIC PROCEDURES: We retrospectively reviewed the outcomes of 1417 LTs performed at Asan Medical Center, Seoul, Korea, from 2020 to 2022. Of these, 216 recipients who received transplants from deceased donors were excluded, and 1201 recipients who received transplants from 1268 live donors were included in the study, including 38 children <18 years old. MAIN FINDINGS: Among the 1201 living donor LT (LDLT) recipients, the most common indication for LT was unresectable hepatocellular carcinoma (315/1163, 27.1%) in adults and biliary atresia (29/38, 76.3%) in pediatric recipients. Emergency LDLT was performed in 40 patients (3.3%). The median model of end-stage liver disease and pediatric end-stage liver disease scores were 13.9 ± 7.2 and 13.8 ± 7.1, respectively. In-hospital mortality of recipients was higher than usual at 2.2%, but the cause of death was not related to COVID-19 infection. Of the 1268 live donors who underwent hepatectomy for liver donation, 660 (52.1%) underwent hepatectomy using a minimally invasive approach. Although 17 (1.3%) live donors experienced major complications, there were no serious life-threatening complications and no mortality. CONCLUSION: Even in a pandemic era, a team with well-established infection control protocols, patient-tailored surgical strategies, and thorough perioperative care can maintain LDLT at a similar quantitative and qualitative level as in a non-pandemic era.