Evaluating the Dialine vascular prosthesis knitted from an alternative source of polyester yarns

The sudden and unilateral decision by E. I. DuPont de Nemours & Co., Inc., to withdraw its polymers for use in implantable devices has presented the medical device industry with an immediate and serious challenge to find alternative sources of biomaterials. In France, the company Cardial S.A. has already taken steps to find an alternative polyester yarn to replace Dacron by developing a new arterial prosthesis knitted from polyester yarns supplied by Rhône-Poulenc Fibres. This article describes an in vitro and in vivo study of this French device, called the Dialine prosthesis, with a view to determining its relative performance compared to current American and British prostheses, which rely on DuPont's Dacron yarn. In addition to analyses of the morphology and textile structure, and measurements of its physical and chemical properties, the Dialine graft was implanted as a thoracoabdominal bypass in dogs for periods ranging from 4 h to 6 months. In addition to our pathologic and histologic observations, we cleaned and evaluated the explanted prostheses for in vivo changes in dimensions, strength, and crystalline microstructure. The Dialine graft was found to differ structurally from other polyester prostheses because it is warp-knitted from a mixture of flat and texturized yarns with finer filaments. Its denser structure has a lower water permeability, greater flexibility and ease of handling, satisfactory strength, and dimensional stability, and it presents different textures on its luminal and external surfaces. The in vivo trial demonstrated that it has excellent biocompatibility and biostability over 6 months. With no thrombi observed on the luminal surface after 3 months, it has a faster rate of healing, generates compact external and internal capsules with a thinner neointima, and has an overall milder inflammatory response than is normally observed with Dacron-based prostheses.