Fibrinogen and Intraoperative Bleeding in Liver Transplant

Study Overview
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Brief Summary
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Liver transplantation is the only treatment for end-stage liver disease. It is a high-risk surgery that can cause heavy intraoperative bleeding. Bleeding and transfusions of blood products are themselves associated with several postoperative complications. Few data have suggested beneficial interventions that can decrease this bleeding. Such interventions are necessary in order to improve these patients' outcomes. In order to better understand the potential therapeutic targets, a better comprehension of the variables associated with such bleeding is essential. Several previous studies have demonstrated a weak association between usual clotting times and bleeding in this population. However, few studies have evaluated the association between the concentration of fibrinogen and bleeding in this population. The primary objective of this study is to assess the association between preoperative serum fibrinogen concentration and the volume of intraoperative bleeding. The secondary objective is to assess the association between preoperative serum fibrinogen concentration and the number of red blood cell units transfused during the intraoperative and immediate postoperative periods. The hypothesis of the study is that a low concentration of preoperative fibrinogen will be associated with an increase in intraoperative bleeding and red blood cell transfusions.

Detailed Description
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All patients who received a liver transplant between July 2008 and January 2021 at the Centre Hospitalier de l'Université de Montréal (CHUM) will be included. The effect of fibrinogen concentration, intraoperative bleeding, intraoperative and postoperative transfusions, as well as postoperative bleeding-related complications and mortality up to 1 year will be assessed. The analysis will be adjusted for several confounding factors, including other coagulation parameters. The main association model will be a multivariable linear regression. This study will be used to further explore the association between fibrinogen concentration and bleeding in liver transplantation. These results may help certain clinical decisions, without suggesting any potential effect of fibrinogen correction on clinical outcomes. If an association is found, the bases will be put in place to build a clinical trial evaluating the effects of a preemptive transfusion of blood products correcting this value on clinical outcomes.

Official Title
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Association Between Fibrinogen Concentration and Intraoperative Bleeding in Liver Transplantation: a Retrospective Observational Study

Conditions
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End Stage Liver DIsease, Liver Transplant; Complications

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients undergoing liver transplant. Exclusion Criteria: Use of cryoprecipitate or fresh frozen plasma after measurement of serum fibrinogen concentration prior to arrival in the operating room. Amyloid neuropathy or liver cancer Fulminant hepatitis Retransplantation

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients undergoing liver transplant for end-stage liver disease<br>The investigators propose to conduct a retrospective cohort study to explore the association between fibrinogen concentration and intraoperative bleeding in patients who underwent a liver transplant between July 2008 and January 2021. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Estimated blood loss per mass of red blood cells lost | In milliliters | Up to 48 hours after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of red blood cell transfusions during liver transplantation | Count | At the end of surgery | 
| Number of perioperative red blood cell transfusions | Count | From the beginning of surgery until 48 hours after surgery | 
| Occurrence of bleeding complications leading to reintervention and / or angioembolization | Dichotomous | 30 days after surgery | 
| Occurrence of early retransplantation | Dichotomous | 30 days after surgery | 
| One year survival | Time to event | One year after surgery |