Fibrin sealants have fewer proven benefits than some other technologies designed to reduce the risks associated with transfusions of donated blood
Fibrin sealants are composed of specific blood clotting agents that, when applied to wound surfaces, help stop bleeding. In liquid form, fibrin sealants are generally sprayed directly onto wound surfaces. They are often used to try to reduce blood loss during and after surgery and therefore avoid blood transfusions. Although fibrin sealant components are derived from blood products, they have a lower risk of transmitting infections than donor blood. The review of trials found that while fibrin sealants can reduce surgical blood loss and the need for blood transfusion, other techniques have been shown to be more cost-effective.
This version first published online:
April 22. 2003
Last assessed as up-to-date:
March 12. 2008
Abstract
Background
Fibrin sealants (also referred to as biological glue or fibrin tissue adhesives) have gained increasing popularity as interventions to improve peri-operative (intra-/post-operative) haemostasis and diminish the need for allogeneic red cell transfusion (blood from an unrelated donor).
Objectives
To examine the efficacy of fibrin sealants in reducing peri-operative blood loss and allogeneic red blood cell (RBC) transfusion.
Search strategy
We identified studies by searching CENTRAL (The Cochrane Library issue 3, 2007), MEDLINE (1950 to 2008), EMBASE (1980 to 2008), manufacturer web sites (to March 2008), and bibliographies of relevant published articles.
Selection criteria
Controlled trials in which adult patients, scheduled for elective surgery, were randomised to fibrin sealant treatment or to a control group which did not receive fibrin sealant treatment. Trials were eligible if they reported data on the number of patients exposed to allogeneic red cell transfusion, the volume of blood transfused, or blood loss (assessed objectively).
Data collection and analysis
Primary outcomes measured were: the number of patients exposed to allogeneic red cells, the amount of blood transfused, and blood loss. Other outcomes measured were: re-operation due to bleeding, infection, mortality, thrombotic events, and length of hospital stay. Treatment effects were pooled using a random-effects model.
Main results
Eighteen trials, including a total of 1406 patients, reported data on peri-operative exposure to allogeneic RBC transfusion. Fibrin sealant treatment, on average, reduced the rate of exposure to allogeneic red cell transfusion by a relative 37% (relative risk (RR) 0.63, 95% confidence interval (CI) 0.45 to 0.88). Fourteen trials, including a total of 853 patients, provided data for post-operative blood loss. Fibrin sealant treatment reduced blood loss on average by around 161 ml per patient (95% CI 98.25 to 224.53 ml). However the trials reviewed were small and of poor methodological quality (82% unblinded).
Authors' conclusions
Overall the results suggest that fibrin sealants are efficacious in reducing both post-operative blood loss and peri-operative exposure to allogeneic RBC transfusion. However, due to the lack of blinding, transfusion practices may have been influenced by knowledge of the patient's treatment status. This raises concerns about the use of blood transfusion practice as an outcome variable in trials of fibrin sealant. In the case of blood loss, the results must be interpreted with caution in view of the statistically significant heterogeneity in treatment effect observed. Large, methodologically rigorous, randomised controlled trials of fibrin sealants are needed.