2020 Clinical Update in Liver Transplantation

Pain management in liver transplant recipients: a focus on current and future strategies

Liver transplantation is the only curative treatment option for patients with end-stage liver disease. Anesthesiologists and intensivists are fully involved in this procedure due to the perioperative care focus on hemodynamic, respiratory and metabolic support. However, quite surprisingly, postoperative pain management does not have clinical primary consideration in this class of patients due to a combination of factors including the thought that liver transplantation recipients have less pain and require lower doses of analgesics than patients who undergo other types of major abdominal surgery. Other factors contribute to make the management of postoperative pain somewhat complex in this class of patients: 1) drug pharmacokinetics and metabolism by the new liver is not predictable; 2) the multifactorial nature of liver graft recovery; and 3) the alterations of homeostasis, including circulatory, respiratory and metabolic vulnerability, in the days postoperative period. As a result, post-liver transplantation analgesia is underestimated not only from the clinical point of view but also in the literature and only a few papers deal with the management of postoperative pain in this particular class of patients. Thus, in the experts' opinion paper we aimed to report the possible strategies for managing post-LT pain with a focus on opioids alternatives and possible future developments in this particular clinical setting also in the view that improvements in perioperative care have made it possible to adopt fast track and Enhanced Recovery After Surgery-oriented protocols also in this class of patients.

Increased Platelet Aggregation in Adults After Orthotopic Liver Transplantation Indicates Higher Probability of Early Postoperative Survival

BACKGROUND Studies have shown that increased platelet aggregation in patients with decompensated cirrhosis indicates higher risk of further decompensation and death, but studies on the association between platelet aggregation function and early postoperative survival in orthotopic liver transplantation (OLT) patients are rare. We conducted a retrospective study to investigate whole-blood platelet aggregation during the perioperative period of OLT patients and its association with clinical outcomes. MATERIAL AND METHODS Adult patients who underwent OLT between January 1 and April 30, 2021 were retrospectively reviewed. Laboratory test results indicating primary hemostasis were analyzed. The generalized linear model was used to investigate the association between primary hemostasis parameters and survival. RESULTS A total of 256 patients were enrolled. The median platelet count (PLT) was 61.5 (39.5-106.3)×109/L before transplantation. The median MA value was 43.1 (34.5-56.2) mm. From the 1st to the 3rd day after transplantation, PLT and MA both indicated a significant decrease. Two weeks after transplantation, PLT rose to 143.0 (85.0-209.0)×10⁹/L, and the MA value rose to 56.7 (52.2-62.7) mm. On multivariate analysis, PLT at 1 week after transplantation (OR: 1.07; P=0.006) and MA value (OR: 1.12; P=0.003) were independently associated with outcome. The AUROC of the model combined with MA value, MELD score, and age was 0.945 (95% CI: 0.911-0.978). CONCLUSIONS The change in primary hemostasis during the early postoperative period of adult OLT is mainly characterized by the increase of platelet count and function 14 days after transplantation. Higher PLT was associated with higher survival at 14 days after transplantation, while a higher PLT ratio was associated with survival at 3 months after transplantation. Based on comprehensive consideration, the model combined with MA value, MELD score, and age more reliably indicated the associated with early survival after transplantation.

Whole Liver Derived Acellular Extracellular Matrix for Bioengineering of Liver Constructs: An Updated Review

Biomaterial templates play a critical role in establishing and bioinstructing three-dimensional cellular growth, proliferation and spatial morphogenetic processes that culminate in the development of physiologically relevant in vitro liver models. Various natural and synthetic polymeric biomaterials are currently available to construct biomimetic cell culture environments to investigate hepatic cell-matrix interactions, drug response assessment, toxicity, and disease mechanisms. One specific class of natural biomaterials consists of the decellularized liver extracellular matrix (dECM) derived from xenogeneic or allogeneic sources, which is rich in bioconstituents essential for the ultrastructural stability, function, repair, and regeneration of tissues/organs. Considering the significance of the key design blueprints of organ-specific acellular substrates for physiologically active graft reconstruction, herein we showcased the latest updates in the field of liver decellularization-recellularization technologies. Overall, this review highlights the potential of acellular matrix as a promising biomaterial in light of recent advances in the preparation of liver-specific whole organ scaffolds. The review concludes with a discussion of the challenges and future prospects of liver-specific decellularized materials in the direction of translational research.

Postreperfusion Syndrome in Liver Transplant: A Risk Factor for Acute Kidney Failure: A Retrospective Analysis

The maximum expression of hemodynamic instability during liver transplant is the so-called postreperfusion syndrome (PRS) that increases both overall mortality and postoperative complications. It was first defined by Aggarwal et al in 1987, but the results are still conflicting when establishing the relationship between PRS and acute kidney failure (AKF). We conducted a retrospective observational study of transplant recipients with deceased-donor liver grafts between January 2002 and December 2018. We analyzed the incidence of PRS and its potential negative impact over kidney function. A total of 551 transplants were analyzed. PRS was recorded in 130 patients (23.6%). The incidence of AKF was 61.5%. A total of 111 patients required kidney replacement therapy (32.7%). Regarding the severity of AKF, 128 patients were classified as acute kidney injury (AKI) 1 (23.2%), 76 as AKI 2 (13.8%), and 135 as AKI 3 (24.5%). In the group with PRS, 75.4% (n = 98) developed AKF vs 57.2% (n = 241) in the group without PRS. In the multivariate analysis we found a relationship between PRS and AKF with an odds ratio of 2.18 (95% CI, 1.30-3.64; P = .003), once adjusted by the length of the anhepatic phase, donor age, Model for End-Stage Liver Disease score, history of ascites, and need for early surgical reintervention. The incidence of AKF decreased (44.5%) ever since the implementation of delayed calcineurin inhibitors therapy and piggyback surgical technique, but a clear influence of the occurrence of PRS on the development of AKF is still observed, with an OR of 3.78 (95% CI, 1.92-7.43; P < .001), once adjusted by albumin and hemoglobin levels, Model for End-Stage Liver Disease score, and Child classification.