[The Dacron vascular prosthesis in men. Mechanical performance, lesions and molecular stability]

The causes of failure of vascular prostheses implanted in man were investigated by means of histological, ultrastructural and scanning electron microscopic techniques as well as mechanical performance and macromolecular structure studies. These investigations concerned 22 out of 212 explanted prostheses from about 10 vascular surgery departments, examined over a 3-year period. The changes observed in the mechanical properties of the explanted prostheses (2 to 75 per cent reduction of resistance to rupture) and the finding of broken fibers and migrating polyester particles were confirmed by the presence of structural alterations in the polymer with, in particular, diminution of its crystalline structure. No correlation was found between the occurrence of these lesions and the type of prosthesis used and/or the duration of implantation.