註釋 Abstract: The constant improvement of operative techniques offers the possibility of treating an increasing number of patients with complex acute and chronic thoracic aortic pathologies involving the aortic arch. Reliable and durable prosthetic material forms the platform for these approaches. Besides the most important properties like impermeability for blood, infection and thrombotic resistance, there are also properties which are not seen at first glance but can nevertheless play a key role in the healing process and long-term results, such as endothelialization and immunostimulation. To ensure the best possible properties of the graft, different variables of the grafts are continuously developed. Beside the choice of material and the weaving technique, Dacron sealing with gelatin is in clinical use for many years but is still being discussed. Collecting clinical experiences with sealed and unsealed grafts in aortic arch replacement led to the conclusion that blood loss through the prosthesis, especially in the early phase after the implantation of the graft, is lowered by gelatin sealing. Furthermore, binding of antimicrobiotic and antithrombotic agents to the collagen are promising approaches to a better prevention of these dreaded complications. More research examining the healing process of the prosthesis is needed in order to find out more about the influence of the prosthesis sealing 