Blood conservation strategies in liver transplantation: Past, present, and future

Abstract

Liver transplantation (LT) is a complex surgical procedure often accompanied by massive intraoperative blood loss, necessitating transfusion of blood and blood products. However, transfusion of allogeneic blood has been consistently associated with adverse outcomes, including increased post-transplant morbidity and mortality, higher rates of infection, acute kidney injury, and reduced graft survival. Allogeneic blood transfusion also exerts immunomodulatory effects that may influence both short- and long-term outcomes, including graft rejection and recurrence of malignancy. Consequently, the development and implementation of effective blood conservation strategies (BCS) have become integral to improving perioperative outcomes in LT recipients. Blood conservation is defined as a patient-centered, evidence-based approach that aims to minimize exposure to allogeneic blood products while ensuring adequate oxygen delivery and hemostasis. The concept encompasses a continuum of interventions beginning in the preoperative period and extending through intraoperative and postoperative management. Preoperative optimization is the cornerstone of modern BCS. Detecting and correcting anemia, thrombocytopenia, and coagulopathy prior to surgery can significantly reduce transfusion needs. Intraoperatively, minimizing iatrogenic blood loss through careful dissection, low central venous pressure anesthesia, and maintenance of normothermia are key components. Acute normovolemic hemodilution (ANH) and intraoperative cell salvage (ICS) enable the collection, washing, and reinfusion of shed autologous red cells, which has been shown to be both safe and effective in LT. The combination of ANH and ICS forms a synergistic approach to intraoperative blood conservation. The use of viscoelastic point-of-care coagulation testing (such as thromboelastography or rotational thromboelastometry) has revolutionized intraoperative transfusion decision-making by allowing goal-directed correction of coagulopathy, thereby avoiding empiric transfusion. Enhanced recovery protocols that facilitate rapid correction of coagulopathy, early nutrition, and reduced infection rates also indirectly reduce transfusion requirements. Looking toward the future, advances in blood substitutes, artificial oxygen carriers, and pharmacologic agents targeting endothelial stabilization and coagulation balance hold promise for further reducing transfusion dependency. Integration of machine learning models for individualized prediction of transfusion needs, along with standardized institutional blood management programs, could transform perioperative care in LT.

Keywords: Liver transplantation; Blood transfusion; Patient blood management; Hemostasis; Antifibrinolytic agents

Core Tip: Blood conservation in liver transplantation is critical to reduce transfusion-related morbidity, cost, and immunological complications. Effective strategies begin preoperatively with optimization of anemia, correction of coagulopathy, and patient selection. Intraoperative measures include low central venous pressure anesthesia, meticulous surgical technique, use of cell salvage, point-of-care coagulation monitoring, and targeted component therapy rather than empirical transfusion. Pharmacological adjuncts such as antifibrinolytics further reduce blood loss. Postoperatively, restrictive transfusion thresholds and ongoing hemostatic monitoring are essential. A multidisciplinary, protocol-driven approach significantly improves outcomes and graft survival.