Fibrinogen concentrates versus cryoprecipitate for intraoperative hypofibrinogenemia in liver transplantation: study protocol for a randomized trial (FIBCRYO-LT trial)

Lyophilized factor concentrates, such as fibrinogen concentrate (FC), are considered superior to frozen products, such as cryoprecipitate, due to their rapid availability. Unlike frozen products, lyophilized factor concentrates do not require thawing or ABO blood type cross-matching, which can be time-consuming. We compared the time required for goal-directed management of hypofibrinogenemia using two strategies during liver transplantation (LT): a conventional cryoprecipitate-based strategy versus a lyophilized fibrinogen concentrate (FC)-based strategy. This randomized trial will be performed in a tertiary university hospital from December 2025 to June 2026. Patients undergoing liver transplantation (LT) who provide written informed consents and develop intraoperative coagulopathy requiring fibrinogen supplementation—defined as serum fibrinogen < 100 mg/dL in standard central lab (SCL) tests or citrated functional fibrinogen maximum amplitude < 15 mm on thromboelastography (TEG6S™)—will be enrolled and randomized (1:1) to receive either cryoprecipitate (Group- C) or fibrinogen concentrate (Group- L). The primary outcome is an inter-group comparison of the treatment time (T-time, the duration from ordering cryoprecipitate or fibrinogen concentrate (FC) to completing its intravenous administration). Secondary outcomes include perioperative bleeding, blood transfusion requirements, coagulation profiles, reoperation, thromboembolic complications, mortality, oxygenation profiles, fibrinolysis phenotypes, bleeding-related costs, and length of hospital stay. A significantly shorter T-time in Group-L would support the superiority of the factor concentrate-based strategy for prompt intraoperative coagulation management during liver transplantation (LT). Its rapidity could reduce bleeding, transfusion requirements, and transfusion-related complications, thereby improving perioperative outcomes. This trial was registered on ClinicalTrials.gov with the registration number of NCT06144112 on November 16, 2023 ( https://classic.clinicaltrials.gov/ct2/show/ NCT06144112).