Development of a model for measurement of adhesion strength of fibrin sealant to human tissue.

It is crucial for the surgeon to know the physical properties of a surgical sealant. Current test methods of fibrin sealant involving animal testing or in vitro testing of sealant using artificial substrates have little clinical relevance. Most of these test methods also lack accuracy and reproducibility. A new model was developed for testing strength and in vitro adhesion of fibrin sealant to vital human tissue using fresh vein leftover from coronary artery bypass grafting. The vein leftover was cut into samples and fastened in a tensiometer linked to a computer. Patient-derived fibrin sealant (0.1 ml) was applied to the tissue, and the surfaces of the tissue samples were held together for 5 min, and then automatically pulled apart by the tensiometer. Data were generated in a load cell and recorded and analysed by the computer. The reproducibility for the adhesion strength was 6.6%, adhesion energy 9.8%, and elongation at break 8.4%. The method has been considered ethical and has good reproducibility. The method can be used for standardised measurements and comparison of different types of fibrin sealant without the sacrifice of animals.