Orthotopic Liver Transplantation Recipients Research Articles

Intraoperative Anesthetic Strategies to Mitigate Early Allograft Dysfunction After Orthotopic Liver Transplantation: A Narrative Review.

Orthotopic liver transplantation (OLT) is the most effective treatment for patients with end-stage liver disease (ESLD). Hepatic insufficiency within a week of OLT, termed early allograft dysfunction (EAD), occurs in 20% to 25% of deceased donor OLT recipients and is associated with morbidity and mortality. Primary nonfunction (PNF), the most severe form of EAD, leads to death or retransplantation within 7 days. The etiology of EAD is multifactorial, including donor, recipient, and surgery-related factors, and largely driven by ischemia-reperfusion injury (IRI). IRI is an immunologic phenomenon characterized by dysregulation of cellular oxygen homeostasis and innate immune defenses in the allograft after temporary cessation (ischemia) and later restoration (reperfusion) of oxygen-rich blood flow. The rising global demand for OLT may lead to the use of marginal allografts, which are more susceptible to IRI, and thus lead to an increased incidence of EAD. It is thus imperative the anesthesiologist is knowledgeable about EAD, namely its pathophysiology and intraoperative strategies to mitigate its impact. Intraoperative strategies can be classified by 3 phases, specifically donor allograft procurement, storage, and recipient reperfusion. During procurement, the anesthesiologist can use pharmacologic preconditioning with volatile anesthetics, consider preharvest hyperoxemia, and attenuate the use of norepinephrine as able. The anesthesiologist can advocate for normothermic regional perfusion (NRP) and machine perfusion during allograft storage at their institution. During recipient reperfusion, the anesthesiologist can optimize oxygen exposure, consider adjunct anesthetics with antioxidant-like properties, and administer supplemental magnesium. Unfortunately, there is either mixed, little, or no data to support the routine use of many free radical scavengers. Given the sparse, limited, or at times conflicting evidence supporting some of these strategies, there are ample opportunities for more research to find intraoperative anesthetic strategies to mitigate the impact of EAD and improve postoperative outcomes in OLT recipients.

Cold stress-induced ferroptosis in liver sinusoidal endothelial cells determines liver transplant injury and outcomes.

Although cold preservation remains the gold standard in organ transplantation, cold stress-induced cellular injury is a significant problem in clinical orthotopic liver transplantation (OLT). Because a recent study showed that cold stress activates ferroptosis, a form of regulated cell death, we investigated whether and how ferroptosis determines OLT outcomes in mice and humans. Treatment with ferroptosis inhibitor (ferrostatin-1) during cold preservation reduced lipid peroxidation (malondialdehyde; MDA), primarily in liver sinusoidal endothelial cells (LSECs), and alleviated ischemia/reperfusion injury in mouse OLT. Similarly, ferrostatin-1 reduced cell death in cold-stressed LSEC cultures. LSECs deficient in nuclear factor erythroid 2-related factor 2 (NRF2), a critical regulator of ferroptosis, were susceptible to cold stress-induced cell death, concomitant with enhanced endoplasmic reticulum (ER) stress and expression of mitochondrial Ca2+ uptake regulator (MICU1). Indeed, supplementing MICU1 inhibitor reduced ER stress, MDA expression, and cell death in NRF2-deficient but not WT LSECs, suggesting NRF2 is a critical regulator of MICU1-mediated ferroptosis. Consistent with murine data, enhanced liver NRF2 expression reduced MDA levels, hepatocellular damage, and incidence of early allograft dysfunction in human OLT recipients. This translational study provides a clinically applicable strategy in which inhibition of ferroptosis during liver cold preservation mitigates OLT injury by protecting LSECs from peritransplant stress via an NRF2-regulatory mechanism.

2739. Evaluation of a Perioperative Fungal Prophylaxis Protocol Change in Orthotopic Liver Transplant

Abstract Background Orthotopic liver transplant (OLT) carries a high rate of fungal infections, including invasive fungal infections (IFI). A targeted antifungal prophylaxis protocol can identify OLT patients who warrant antifungal prophylaxis and optimize agent selection. In January 2021, a targeted antifungal prophylaxis post-liver transplant protocol was implemented at Cleveland Clinic. Since its introduction, rates of fungal infections and adherence to the protocol have not been assessed. The goal of this project is to describe the impact of a protocol change in OLT recipients. Methods This was a retrospective observational cohort study of patients ≥ 18 years old with an OLT +/- sequential kidney transplant at Cleveland Clinic. Review of perioperative fungal prophylaxis from June 1, 2019 – May 31, 2020 was performed and used as the baseline. The post-intervention period was June 1, 2021 – May 31, 2022. The primary objective was to determine adherence to the new OLT fungal prophylaxis protocol on post-operative day (POD) 0. Secondary objectives included the 90-day incidence of proven or probable IFI post-OLT before and after implementation. Study Population Results A total of 134 patients pre-protocol and 166 patients post-protocol were included. Prior to protocol implementation, 73% patients were prescribed clotrimazole, 13% fluconazole, 13% micafungin, and 1% nystatin. After protocol implementation, 63% were prescribed clotrimazole, 16% fluconazole, and 21% micafungin. In the post-protocol group, there was an adherence rate of 66% on POD0 which increased to 84% over the duration of prophylaxis. Prior to initiation of the antifungal protocol, 6.7% of patients developed an IFI while 3.6% of patients developed an IFI post-protocol (p=0.22). Median time to IFI was 8 days (IQR 2-19) pre-protocol and 15 days (IQR 6-17) post-protocol. Mortality and ICU length of stay were comparable between groups. Primary and Secondary Results OLT: orthotopic liver transplant; POD: post-operative day; ICU: intensive care unit; IFI: invasive fungal infection Characteristics of Patients with Invasive Fungal Infections IFI: invasive fungal infection; TPN: total parenteral nutrition; IAI: intra-abdominal infection; n/a: not applicable; pRBC: packed red blood cells; OR: operating room; RRT: renal replacement therapy; ICU: intensive care unit; Dose dep.: dose dependent; GI: gastrointestinal Conclusion The implementation of a targeted antifungal prophylaxis post-liver transplant protocol can be a powerful strategy for promoting consistency in antifungal prophylaxis within a population at high risk for IFIs. Our study showed an 84% adherence rate to the implemented protocol, with numerically lower rates of IFIs post-protocol compared to pre-protocol. Disclosures All Authors: No reported disclosures

EVIDENCE FOR BENEFICIAL USE OF THE COMPENSATORY RESERVE MEASUREMENT IN GUIDING INTRAOPERATIVE RESUSCITATION: A PROSPECTIVE COHORT STUDY OF ORTHOTOPIC LIVER TRANSPLANT RECIPIENTS.

Introduction: The compensatory reserve measurement (CRM) is a continuous noninvasive monitoring technology that provides an assessment of the integrated capacity of all physiological mechanisms associated with responses to a hypovolemic stressor such as hemorrhagic shock. No prior studies have analyzed its use for intraoperative resuscitation guidance. Methods: A prospective observational study was conducted of 23 patients undergoing orthotopic liver transplant. Chart review was performed to identify timing of various intraoperative events. Data were compared based on predefined thresholds for existence of hemorrhagic shock: CRM lower than 40%, systolic blood pressure (SBP) lower than 90 mm Hg (SBP90), and heart rate (HR) higher than 100 beats per minute (HR100). Regression analysis was performed for predicting resuscitation events, and nonlinear eXtreme Gradient Boosting (XGBoost) models were used to compare CRM with standard vital sign measures. Results: Events where CRM dropped lower than 40% were 2.25 times more likely to lead to an intervention, whereas HR100 and SBP90 were not associated with intraoperative interventions. XGBoost prediction models showed superior discriminatory capacity of CRM alone compared with the model with SBP and HR and no difference when all three were combined (CRM-HR-SBP). All XGBoost models outperformed equivalent linear regression models. Conclusion: These results demonstrate that CRM can provide an adjunctive clinical tool that can augment early and accurate of hemodynamic compromise and promote goal-directed resuscitation in the perioperative setting.

Role of a Real-Time TDM-Based Expert Clinical Pharmacological Advice Program in Optimizing the Early Pharmacokinetic/Pharmacodynamic Target Attainment of Continuous Infusion Beta-Lactams among Orthotopic Liver Transplant Recipients with Documented or Suspected Gram-Negative Infections.

(1) Objectives: To describe the attainment of optimal pharmacokinetic/pharmacodynamic (PK/PD) targets in orthotopic liver transplant (OLT) recipients treated with continuous infusion (CI) beta-lactams optimized using a real-time therapeutic drug monitoring (TDM)-guided expert clinical pharmacological advice (ECPA) program during the early post-surgical period. (2) Methods: OLT recipients admitted to the post-transplant intensive care unit over the period of July 2021-September 2023, receiving empirical or targeted therapy with CI meropenem, piperacillin-tazobactam, meropenem-vaborbactam, or ceftazidime-avibactam optimized using a real-time TDM-guided ECPA program, were retrospectively retrieved. Steady-state beta-lactam (BL) and/or beta-lactamase inhibitor (BLI) plasma concentrations (Css) were measured, and the Css/MIC ratio was selected as the best PK/PD target for beta-lactam efficacy. The PK/PD target of meropenem was defined as being optimal when attaining a fCss/MIC ratio > 4. The joint PK/PD target of the BL/BLI combinations (namely piperacillin-tazobactam, ceftazidime-avibactam, and meropenem-vaborbactam) was defined as being optimal when the fCss/MIC ratio > 4 of the BL and the fCss/target concentration (CT) ratio > 1 of tazobactam or avibactam, or the fAUC/CT ratio > 24 of vaborbactam were simultaneously attained. Multivariate logistic regression analysis was performed for testing potential variables that were associated with a failure in attaining early (i.e., at first TDM assessment) optimal PK/PD targets. (3) Results: Overall, 77 critically ill OLT recipients (median age, 57 years; male, 63.6%; median MELD score at transplantation, 17 points) receiving a total of 100 beta-lactam treatment courses, were included. Beta-lactam therapy was targeted in 43% of cases. Beta-lactam dosing adjustments were provided in 76 out of 100 first TDM assessments (76.0%; 69.0% decreases and 7.0% increases), and overall, in 134 out of 245 total ECPAs (54.7%). Optimal PK/PD target was attained early in 88% of treatment courses, and throughout beta-lactam therapy in 89% of cases. Augmented renal clearance (ARC; OR 7.64; 95%CI 1.32-44.13) and MIC values above the EUCAST clinical breakpoint (OR 91.55; 95%CI 7.12-1177.12) emerged as independent predictors of failure in attaining early optimal beta-lactam PK/PD targets. (4) Conclusion: A real-time TDM-guided ECPA program allowed for the attainment of optimal beta-lactam PK/PD targets in approximately 90% of critically ill OLT recipients treated with CI beta-lactams during the early post-transplant period. OLT recipients having ARC or being affected by pathogens with MIC values above the EUCAST clinical breakpoint were at high risk for failure in attaining early optimal beta-lactam PK/PD targets. Larger prospective studies are warranted for confirming our findings.

Predictive Value of Fatty Liver Index for Long-Term Cardiovascular Events in Patients Receiving Liver Transplantation: The COLT Study.

Cardiovascular disease (CVD) is the leading cause of early mortality in orthotopic liver transplantation (OLT) patients. The fatty liver index (FLI) is strongly associated with carotid and coronary atherosclerosis, as well as cardiovascular mortality, surpassing traditional risk factors. Given the lack of data on FLI as a predictor of cardiovascular events in OLT recipients, we conducted a retrospective study to examine this topic. We performed a multicenter retrospective analysis of adult OLT recipients who had regular follow-up visits every three to six months (or more frequently if necessary) from January 1995 to December 2020. The minimum follow-up period was two years post-intervention. Anamnestic, clinical, anthropometric and laboratory data were collected, and FLI was calculated for all patients. gov registration ID NCT05895669. A total of 110 eligible patients (median age 57 years [IQR: 50-62], 72.7% male) were followed for a median duration of 92.3 months (IQR: 45.7-172.4) post-liver transplantation. During this period, 16 patients (14.5%) experienced at least one adverse cardiovascular event (including fatal and non-fatal myocardial infarction and stroke). Receiver Operating Characteristic (ROC) analysis identified a cut-off value of 66.0725 for predicting cardiovascular events after OLT, with 86.7% sensitivity and 63.7% specificity (68% vs. 31%; p = 0.001). Kaplan-Meier analysis showed that patients with FLI > 66 had significantly reduced cardiovascular event-free survival than those with FLI ≤ 66 (log-rank: 0.0008). Furthermore, multivariable Cox regression analysis demonstrated that FLI > 66 and pre-OLT smoking were independently associated with increased cardiovascular risk. Our findings suggest that FLI > 66 and pre-OLT smoking predict cardiovascular risk in adult OLT recipients.

Celiac trunk stenosis by median arcuate ligament in orthotopic liver transplantation: a potential hidden foe to the biliary tree

BackgroundCeliac trunk compression by the median arcuate ligament (MAL) increases the risk of ischemic complications following gastrointestinal surgical procedures. Previous studies suggest increased risk of hepatic artery thrombosis (HAT) in orthotopic liver transplant (OLT) recipients. The aim of this study is to investigate the impact of untreated MAL compression (MAL-C) on biliary complications in OLT. MethodsContrast-enhanced imaging was used to classify celiac trunk stenosis by MAL-C. Medical records were reviewed to extract pre-transplant, transplant and post-transplant data. Patients were divided into two groups: no MAL compression (nMAL-C) and MAL-C. The primary endpoint was biliary complications. Secondary endpoints were HAT and graft survival. Results305 OLT were performed from 2010 to 2021, of which 219 were included for analysis: 185 (84.5%) patients without and 34 (15.5%) with MAL-C. The incidence of HAT was 5.9% in both groups. Biliary complications were more common in the MAL-C group (35.3% vs. 17.8%, p = 0.035). Graft survival was decreased in patients with MAL-C (p = 0.035). ConclusionsMAL-C of the celiac trunk was associated with increased risk of biliary complications and inferior graft survival in OLT patients. These findings highlight the importance of preoperative screening and treatment of MAL in this population.

Early Intra-Abdominal Bacterial Infections after Orthotopic Liver Transplantation: A Narrative Review for Clinicians.

Despite recent advances in the transplant field, infectious complications after orthotopic liver transplantation (OLT) are major causes of morbidity and mortality. Bacterial intra-abdominal infections (IAIs) are predominant during the first month post-transplantation and affect patient and graft survival. Recently, the emergence of multidrug resistant bacteria has generated great concern in OLT patients. We performed this narrative review of the literature in order to propose a "ready-to-use" flowchart for reasoned empirical antibiotic therapy in the case of suspected post-OLT IAIs. The review was ultimately organized into four sections: "Epidemiology and predisposing factors for IAI"; "Surgical-site infections and perioperative prophylaxis"; "MDRO colonization and infections"; and "Reasoned-empirical antibiotic therapy in early intra-abdominal infections post OLT and source control". Multidisciplinary teamwork is warranted to individualize strategies for the prevention and treatment of IAIs in OLT recipients, taking into account each patient's risk factors, the surgical characteristics, and the local bacterial epidemiology.

Disulfide-HMGB1 signals through TLR4 and TLR9 to induce inflammatory macrophages capable of innate-adaptive crosstalk in human liver transplantation

Ischemia-reperfusion injury (IRI) during orthotopic liver transplantation (OLT) contributes to graft rejection and poor clinical outcomes. The disulfide form of high mobility group box 1 (diS-HMGB1), an intracellular protein released during OLT-IRI, induces pro-inflammatory macrophages. How diS-HMGB1 differentiates human monocytes into macrophages capable of activating adaptive immunity remains unknown. We investigated if diS-HMGB1 binds toll-like receptor (TLR) 4 and TLR9 to differentiate monocytes into pro-inflammatory macrophages that activate adaptive immunity and promote graft injury and dysfunction. Assessment of 106 clinical liver tissue and longitudinal blood samples revealed that OLT recipients were more likely to experience IRI and graft dysfunction with increased diS-HMGB1 released during reperfusion. Increased diS-HMGB1 concentration also correlated with TLR4/TLR9 activation, polarization of monocytes into pro-inflammatory macrophages, and production of anti-donor antibodies. In vitro, healthy volunteer monocytes stimulated with purified diS-HMGB1 had increased inflammatory cytokine secretion, antigen presentation machinery, and reactive oxygen species production. TLR4 inhibition primarily impeded cytokine/chemokine and costimulatory molecule programs, whereas TLR9 inhibition decreased HLA-DR and reactive oxygen species production. diS-HMGB1–polarized macrophages also showed increased capacity to present antigens and activate T memory cells. In murine OLT, diS-HMGB1 treatment potentiated ischemia-reperfusion–mediated hepatocellular injury, accompanied by increased serum alanine transaminase levels. This translational study identifies the diS-HMGB1/TLR4/TLR9 axis as potential therapeutic targets in OLT-IRI recipients.

Recipient TIM4 signaling regulates ischemia reperfusion-induced ER stress and metabolic responses in liver transplantation: from mouse-to-human

T-cell immunoglobulin and mucin (Tim)4 is expressed on APCs, including macrophages, as one of the main amplifiers in the mechanism of liver ischemia-reperfusion injury (IRI) following orthotopic liver transplantation (OLT). Though donor Tim4 selectively expressed on Kupffer cells serves as a checkpoint regulator of innate immune-driven IRI cascades, its role on cells outside the OLT remains unclear. To dissect the role of donor vs. recipient-specific Tim4 signaling in IR-induced stress and hepatocellular function, we employed a murine OLT model utilizing Tim4-knockout (KO) mice as either donor or recipient (WT → WT, WT → Tim4-KO, Tim4-KO → WT). In the experimental arm, disruption of donor Tim4 attenuated IRI-OLT damage, while recipient Tim4-null mutation aggravated hepatic IRI concomitant with disturbed lipid metabolism, enhanced endoplasmic reticulum stress, and activated pro-apoptotic signaling in the grafts. In the in vitro study, murine hepatocytes co-cultured with Tim4-null adipose tissue showed enhanced C/EBP homologous protein (CHOP) expression pattern and susceptibility to hepatocellular death accompanied by activated caspase cascade in response to TNF-α stimulation. In the clinical arm, liver grafts from forty-one transplant patients with enhanced TIM4 expression showed higher body mass index, augmented hepatic endoplasmic reticulum stress, enhanced pro-apoptotic markers, upregulated innate/adaptive immune responses, exacerbated hepatocellular damage, and inferior graft survival. In conclusion, although TIM4 is considered a principal villain in peri-transplant early tissue injury, recipient TIM4 signaling may serve as a savior of IR-triggered metabolic stress in mouse and human OLT recipients.

Research Highlights.

Research Highlights.

Increased Imminent Fracture Risk in Liver Transplant Recipients Despite Bisphosphonate Therapy

Bone loss is significant after orthotopic liver transplant (OLT) and is associated with increased fracture risk and decreased quality of life. In post-transplant fracture prevention, the cornerstone of therapeutic management is bisphosphonates. We conducted a retrospective study in a cohort of 155 OLT recipients who received a bisphosphonate prescription at hospital discharge between 2012 and 2016 to investigate post-OLT fragility fracture incidence and predictive risk factors. Before OLT, 14 patients presented a T score < -2.5 SD, and 23 patients (14.8%) had a history of fracture. During follow-up, the cumulative incidence of fractures on bisphosphonates (99.4% risedronate/alendronate) was 9.7% at 12 months and 13.1% at 24 months. The median time to first fragility fracture was 10 months (IQR, 3-22 months) and thus within the first 2 years of follow-up. Predictive factors of fragility fractures in multivariate Cox regression analyses included age 60 years or older (hazard ratio [HR], 2.61; 95% CI, 1.14-6.01; P=.02), post-transplant diabetes mellitus (HR, 3.82; 95% CI, 1.55-9.44; P=.004), and cholestatic disease (HR, 5.93; 95% CI, 2.30-15.26; P=.0002). Additionally, the female sex was associated with a strong trend toward increased fracture risk in univariate analysis (HR, 2.27; 95% CI, 1.00-5.15; P=.05), as well as a post-transplant absolute decrease in bone mineral density at the femoral neck and total hip (P=.08). This real-world study reports a high incidence of fractures post-OLT despite bisphosphonate therapy. Age 60 years or older, post-transplant diabetes mellitus, cholestatic disease, female sex, and femoral neck and/or total hip bone mineral density loss contribute to increased imminent fracture risk in liver transplant recipients.

Implications of Pleural Fluid Composition in Persistent Pleural Effusion following Orthotopic Liver Transplant

Persistent pleural effusions (PPEf) represent a known complication of orthotopic liver transplant (OLT). However, their clinical relevance is not well described. We evaluated the clinical, biochemical, and cellular characteristics of post-OLT PPEf and assessed their relationship with longitudinal outcomes. We performed a retrospective cohort study of OLT recipients between 2006 and 2015. Included patients had post-OLT PPEf, defined by effusion persisting >30 days after OLT and available pleural fluid analysis. PPEf were classified as transudates or exudates (ExudLight) by Light's criteria. Exudates were subclassified as those with elevated lactate dehydrogenase (ExudLDH) or elevated protein (ExudProt). Cellular composition was classified as neutrophil- or lymphocyte-predominant. Of 1602 OLT patients, 124 (7.7%) had PPEf, of which 90.2% were ExudLight. Compared to all OLT recipients, PPEf patients had lower two-year survival (HR 1.63; p = 0.002). Among PPEf patients, one-year mortality was associated with pleural fluid RBC count (p = 0.03). While ExudLight and ExudProt showed no association with outcomes, ExudLDH were associated with increased ventilator dependence (p = 0.03) and postoperative length of stay (p = 0.03). Neutrophil-predominant effusions were associated with increased postoperative ventilator dependence (p = 0.03), vasopressor dependence (p = 0.02), and surgical pleural intervention (p = 0.02). In summary, post-OLT PPEf were associated with increased mortality. Ninety percent of these effusions were exudates by Light's criteria. Defining exudates using LDH only and incorporating cellular analysis, including neutrophils and RBCs, was useful in predicting morbidity.

CD4+ T Cell NRF2 Signaling Improves Liver Transplantation Outcomes by Modulating T Cell Activation and Differentiation.

Aims: Innate and adaptive immune responses regulate hepatic ischemia-reperfusion injury (IRI) in orthotopic liver transplantation (OLT). While the mechanism of how nuclear factor erythroid 2-related factor 2 (NRF2) plays a role in liver IRI has been studied, the contribution of T cell-specific NRF2 in OLT remains unknown. In the current translational study, we investigated whether and how CD4+ T cell-specific NRF2 signaling affects liver transplant outcomes in mice and humans. Results: In the experimental arm, cold-stored (4°C/18 h) wild-type (WT) mouse livers transplanted to NRF2-deficient (NRF2-knockout [NRF2-KO]) recipients experienced greater hepatocellular damage than those in Nrf2-proficient (WT) counterparts, evidenced by Suzuki's histological scores, frequency of TdT-mediated dUTP nick end labeling (TUNEL)+ cells, and elevated serum aspartate aminotransferase/alanine aminotransferase (AST/ALT) levels. In vitro studies showed that NRF2 signaling suppressed CD4+ T cell differentiation to a proinflammatory phenotype (Th1, Th17) while promoting the regulatory (Foxp3+) T cell lineage. Furthermore, OLT injury deteriorated in immune-compromised RAG2-KO test recipients repopulated with CD4+ T cells from NRF2-KO compared with WT donor mice. In the clinical arm of 45 human liver transplant patients, the perioperative increase of NRF2 expression in donor livers negatively regulated innate and adaptive immune activation, resulting in reduced hepatocellular injury in NRF2-proficient OLT. Innovation and Conclusion: CD4+ T cell population expressing NRF2 attenuated ischemia and reperfusion (IR)-triggered hepatocellular damage in a clinically relevant mouse model of extended donor liver cold storage, followed by OLT, whereas the perioperative increase of NRF2 expression reduced hepatic injury in human liver transplant recipients. Thus, CD4+ T cell NRF2 may be a novel cytoprotective sentinel against IR stress in OLT recipients. Antioxid. Redox Signal. 38, 670-683.

Neutrophil CEACAM1 determines susceptibility to NETosis by regulating the S1PR2/S1PR3 axis in liver transplantation.

Neutrophils, the largest innate immune cell population in humans, are the primary proinflammatory sentinel in the ischemia-reperfusion injury (IRI) mechanism in orthotopic liver transplantation (OLT). Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1, CC1, or CD66a) is essential in neutrophil activation and serves as a checkpoint regulator of innate immune-driven IRI cascade in OLT. Although CC1 alternative splicing generates two functionally distinct short and long cytoplasmic isoforms, their role in neutrophil activation remains unknown. Here, we undertook molecular and functional studies to interrogate the significance of neutrophil CC1 signaling in mouse and human OLT recipients. In the experimental arm, we employed a mouse OLT model to document that ablation of recipient-derived neutrophil CC1-long (CC1-L) isotype aggravated hepatic IRI by promoting neutrophil extracellular traps (NETs). Notably, by regulating the S1P-S1PR2/S1PR3 axis, neutrophil CC1-L determined susceptibility to NET formation via autophagy signaling. In the clinical arm, liver grafts from 55 transplant patients selectively enriched for neutrophil CC1-L showed relative resistance to ischemia-reperfusion (IR) stress/tissue damage, improved hepatocellular function, and clinical outcomes. In conclusion, despite neutrophils being considered a principal villain in peritransplant tissue injury, their CC1-L isoform may serve as a regulator of IR stress resistance/NETosis in human and mouse OLT recipients.

Transjugular Intrahepatic Portosystemic Shunt in Liver Transplant Recipients: Outcomes in Six Adult Patients.

Transjugular intrahepatic portosystemic shunt (TIPS) is regularly used in treatment of clinically significant portal hypertension. Liver transplant recipients are, however, rarely indicated for the procedure. The study retrospectively examines the results of TIPS placement in 6 patients after OLT. 4 males and 2 females (aged 36 to 62years), treated with TIPS between 2007 a 2018, were included in the study. 5 patients had previously undergone liver transplantation for liver graft cirrhosis, 1 patient for Budd-Chiari syndrome. The piggyback caval reconstruction technique was selected in 4/6 cases. PH developed after OLT due to the recurrence of underlying liver condition and sinusoidal obstruction syndrome in half of the cases, respectively. Indications for TIPS were refractory ascites in 4 cases and variceal bleeding in 2 cases. Standard TIPS technique was used and technical success was achieved in all cases with a procedure-related complication in 1 patient. One patient died shortly after TIPS placement. The remaining patients all reported regression of clinically significant PH. Late complications appeared in 2 patients. Liver retransplantation after TIPS creation was performed in 1 case. Median TIPS patency was 55months. 2/6 patient continue to thrive with a patent shunt. Transjugular intrahepatic portosystemic shunt in OLT recipients is technically feasible. Favorable clinical outcomes were reported particularly in patients treated for sinusoidal obstruction syndrome who were indicated to TIPS for refractory ascites.

Reverse Takotsubo Stress Cardiomyopathy During Liver Transplantation

Reverse Takotsubo Stress Cardiomyopathy During Liver Transplantation

Reduced humoral but stable cellular SARS-CoV-2-specific immunity in liver transplant recipients in the first year after COVID-19

Mortality due to COVID-19 is not increased in immunosuppressed individuals after liver transplantation (OLT) compared to individuals without immunosuppression. Data on long-term protective immunity against SARS-CoV-2 in immunosuppressed convalescents, is limited. We prospectively measured immune responses against SARS-CoV-2 by quantifying antibodies against 4 different antigens (spike protein 1 and 2, receptor binding domain, nucleocapsid) and T cell responses by IFN-γ ELISPOT against 4 antigens (membrane, nucleocapsid, spike protein 1 and 2) in 24 OLT convalescents with immunosuppressive therapy longitudinally in the first year after COVID-19 including a booster vaccination in comparison to a matched cohort of non-immunosuppressed convalescents (non-IS-Con). Pre-pandemic OLT samples were retrieved from our prospective OLT biorepository (n = 16). No relevant T cell reactivity or immunoglobulin G (IgG) against SARS-CoV-2 were detectable in pre-pandemic samples of OLT recipients despite reactivity against endemic corona-viruses. OLT convalescents had a lower prevalence of IgG against nucleocapsid (54% vs. 90%) but not against spike protein domains (98-100% vs. 100%) after vaccination in the second half-year after COVID-19 compared to non-IS-Con. Also, concentrations of anti-nucleocapsid IgG were lower in OLT convalescents than in non-IS-Con. Concentration of IgG against spike protein domains was significantly increased by a booster vaccination in OLT convalescents. But concentration of IgG against two of three spike protein domains remains slightly lower compared to non-IS-Con finally. However, none of these differences was mirrored by the cellular immunity against SARS-CoV-2 that remained stable during the first year after COVID-19 and was not further stimulated by a corona vaccination in OLT convalescents. In conclusion, despite lower concentrations of anti-SARS-CoV-2 IgG in OLT convalescents anti-SARS-CoV-2 cellular immunity was as robust as in non-IS-Con.

Impact of Point-of-Care Assays for Hemostasis Monitoring According to Type of Donor in a Cohort of Liver Transplant Recipients

• Donation after circulatory death liver transplant offers excellent outcomes. • Perioperative hemostasis monitoring protocols with a viscoelastic point-of-care testing assay reduce blood loss and transfusion volume. • Use of machine perfusion is likely to further expand donation after circulatory death liver transplant. The aim is to compare 2 groups of liver transplant recipients, according to type of donor, within the framework of a hemostasis monitoring program using a point-of-care testing assay in terms of reduction in transfusion of blood products. This retrospective analytical observational study included 527 liver transplant recipients from 2014 to 2021. Of these, 460 were recipients of livers from donation after brain death (DBD) and 67 were orthotopic liver transplant recipients with donation after cardiac death (DCD). Statistical analysis of differences between the 2 groups included a series of intraoperative variables of blood product consumption: erythrocyte concentrate (red blood cells), fresh frozen plasma, platelets, and fibrinogen concentrates guided by algorithm with a viscoelastic technique using the ClotPro analyzer. The transfusion management was decided according to pre-established guidelines and cutoff values. The mean follow-up period was 40.3 months. Transfused red blood cells and fibrinogen units were significantly higher in the DBD group. The percentage of retransplant was significantly higher in the DCD group, and vascular complications were significantly more frequent in the DCD group ( P < .05). Cox univariate analysis showed that the DCD group had a risk ratio of death significantly higher than 1. Intraoperative monitoring of hemostasis with a point-of-care testing assay reduced blood product requirements. Type of donor had prognostic utility in our cohort. We hypothesize that other variables such as extraction technique, methods used to preserve the allograft, and later complications have a significantly greater impact than perioperative hemostasis management on retransplant rates and death.

Feasible management of median arcuate ligament syndrome in orthotopic liver transplantation recipients.

BACKGROUNDIn orthotopic liver transplantation (OLT) recipients, median arcuate ligament syndrome (MALS) is considered a risk factor for hepatic arterial thrombosis (HAT), which is dreadful for OLT recipients. Different alternative surgical procedures have been proposed to overcome the impact of MALS on transplantation, but clinical evidence is still scarce. AIMTo evaluate the feasible surgical management of MALS to reduce complications in OLT patients.METHODSData for 288 consecutive patients who underwent OLT at The First Hospital of Jilin University between January 2017 and July 2020 were retrospectively reviewed. The surgical management of median arcuate ligament (MAL) and modifications to the arterial anastomosis were recorded. The perioperative and long-term prognosis of MALS recipients were noted. Detailed preoperative and postoperative data of patients were analyzed in a descriptive manner.RESULTSEight patients with MALS were included in this study. The first patient with MALS received no intervention during the primary surgery and developed postoperative HAT. Salvage liver transplantation with MAL division was successfully performed. Gastroduodenal artery (GDA) preservation with splenic artery ligation was performed on three patients, only GDA preservation was performed on two patients, and no intervention was performed on two patients. No patient developed HAT after surgery and postoperative recovery was satisfactory. CONCLUSIONThe preservation of collateral circulation between the superior mesenteric artery and celiac trunk via the GDA with or without splenic artery ligation is a safe and feasible alternative to MAL division.