The optimal technique for combined application of fibrin sealant and bioabsorbable felt against alveolar air leakage

Objectives: The combination of fibrin sealant and bioabsorbable sheet is known to provide a better sealing effect on alveolar air leakage compared to the single use of fibrin sealant. However, there is little evidence that reveals the optimum techniques for their combined application. Presently we developed a novel Rub + Soak B method that comprises the attachment of thrombin-impregnated sheet to the fibrinogen-rubbed lung tissue area. This study aimed to evaluate its sealing effect compared to various combined application techniques. Methods: Experiment I: The viscosity and osmolality of each fibrin sealant component weremeasured. Experiment II: Pleural defects produced by electrocauterization in retrieved swine lungs (n = 24) were covered with fibrin sealant and polyglycolic acid felt by using the following five techniques: concomitant spraying of fibrinogen and thrombin solutions over the pleural defect area (Group I, Control); rubbing the thrombin solution on the area, attaching the felt soaked in the fibrinogen solution, and applying the remaining thrombin and fibrinogen solutions (half the original quantity) alternately to the area (Group II, Rub + Soak A); rubbing the fibrinogen solution on the area, attaching the felt soaked in the thrombin solution, and applying the remaining fibrinogen and thrombin solutions alternately to the area (Group III, Rub + Soak B); rubbing the fibrinogen solution on the area, attaching the dry felt, and spraying both the remaining solutions concomitantly (Group IV, Rub + Spray); and spraying both the solutions, attaching the dry felt, and respraying the remaining solutions over the area (Group V, Spray Sandwich). Theminimum seal-breaking airway pressure was compared among the groups. Samples were histologically assessed. Results: Experiment I: The fibrinogen solution was 34.8 times more viscous and had 3.5 times higher osmolality than the thrombin solution. Experiment II: The seal-breaking pressure was significantly higher in Group III than in Groups I, II, and V ( p < 0.05). Histologically, clot penetration into the tissue was significant in Group III. Conclusions: The novel Rub + Soak B technique was the most effective and reasonable combination technique wherein the sealing mechanism was supported by the physical properties of the fibrin sealant components. # 2007 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.