The resorbable pericardial substitute: In modern heart surgery every patient undergoing cardiac surgery will eventually require a second operation including resternotomy. To reduce the risk of damage to the heart it has been recommended to close the pericardial sac primarily. Unfortunately there is no ideal pericardial substitute yet available. This experimental study summarizes our experience with the use of Gore-Tex Surgical Membrane and Vicryl-Collagen mesh as pericardial substitutes which have been implanted orthotopically in 12 rats. After a mean follow-up of 86 days we evaluated macroscopically the pericardial adhesions, the closure of the pericardial defect and histologically the inflammatory reaction. At explanation we found that both pericardial substitutes produce little adhesion. But in rats with Vicryl-Collagen mesh as a pericardial substitute there were only a very few inflammatory cells and total closure of the pericardial defect was in 4 out of 6 rats present. These findings suggest that Vicryl-Collagen mesh seems to be a superior pericardial substitute and also allows formation of a neopericardium.