New Concepts and Development of Vascular Graft Prostheses

Abstract

There are several kinds of vascular graft prostheses, such as fabric Dacron prostheses, biological grafts, EPTFE grafts, cell seeding grafts, chemically treated connective tissue tube grafts, etc. They have been used safely in clinic, although with advantages and disadvantages. The biggest disadvantages are the poor healing ability of the neointima and lack of antithrombogenicity. Therefore, they cannot be used as venous and small diameter arterial grafts. For example, fabric Dacron prostheses have no natural antithrombogenicity. The surface is covered with fresh thrombi for a long period of time after implantation. Endothelialization of the grafts is limited to areas near the anastomotic sites. Conversely, EPTFE grafts have been expected to prevent thrombus formation. The grafts are hydrophobic and have less adhesive property. They can prevent the hydrophilic substances, but, hydrophobic substances can adhere to it followed by thrombi. Biological grafts are also not antithrombogenic and have a thrombus layer on the lumenal surface. If these grafts have an excellent healing ability of the neointima, they can maintain their patency for long periods of time with a powerful anticoagulant therapy just after implantation.