FIBRIN SEALANT - CURRENT AND POTENTIAL CLINICAL-APPLICATIONS

There are few well-controlled studies of the clinical efficacy of fibr in sealant, defined by lives saved or reduced need for blood transfusi ons. Evaluation of fibrin sealant in trauma situations, e.g. liver lac eration, has been difficult to perform. Only recently has fibrin seala nt been actively promoted by US manufacturers as a commercially valuab le alternative to the relatively inexpensive crude bovine thrombin and cryoprecipitate that are in current use. Regulatory agencies and manu facturers are aware that patients in the USA are receiving a suboptima l form of fibrin glue since cryoprecipitate is not virally inactivated and has a variable fibrinogen concentration. In addition, bovine thro mbin is not regulated with respect to factor V content or any other im purities. During the past year regulatory agencies, together with manu facturers and clinicians, have begun to define clinically valid endpoi nts for efficacy of a commercially prepared fibrin sealant. These may include improvement in hemostasis compared with a placebo or agents co nsidered to be 'standard of care'. Thus, the regulatory agencies may b e willing to consider studies in animals that demonstrate efficacy as well as surrogate endpoints, such as reduced factor concentrate requir ements in patients with severe hemophilia requiring dental extraction. As fibrin sealant becomes available in a liquid and potentially in a bandage form, it may also become an essential matrix for recombinant f actors that can affect endothelial function.