The safety and efficacy of fibrinogen and thrombin-based collagen fleece for treatment of pleural injury

Results A total of 20 TachoSil were applied to pleural defects. All animals survived thorough the observational period. No pneumothorax was found and two adhesions (10%) were observed on the pleura covered by TachoSil at the time of sacrifice. Tachosil was macroscopically detectable until POD 28 and only macroscopically detectable on POD 56. Histologically, inflammatory cells infiltrated the TachoSil from the pleural defect, and pleural mesothelium comprised the regenerated outermost layer of the TachoSil until POD 4. Inflammatory cells, myofibroblasts and neovascular vessels then spread over the entire TachoSil. The number of inflammatory cells decreased, and then myofibroblast and neovascular vessels replaced the entire TachoSil, which was not left as foreign material. In addition, the elastic layer started to regenerate from both edges and completely repaired the pleural defect. Importantly, the lung parenchyma was not influenced because these healing processes occurred only inside the TachoSil.