A rapid in vitro test of the in vivo healing potential of vascular prostheses

An in vitro method for comparing the penetration of bovine fibroblasts seeded on the external surface of porous vascular prostheses was devised. The effects of water porosity reduction and differing manufacturing constructions (warp-knit Dacron, woven Dacron and polytetrafluoroethylene) on the ability of the bovine fibroblasts to penetrate transmurally was investigated. Of the warp-knit external-veloured Dacron prostheses, the highest porosity 140-denier prototype had the highest luminal surface cell count and the lowest porosty 280-denier prototype the lowest luminal surface cell count. The intermediate prototypes had values between these two extremes. The woven Dacron prostheses which were of even lower porosity but with a much thinner wall, had cell counts midway between the 140-denier and the 280-denier prototypes. The microporous polytetrafluoroethylene prostheses did not allow fibroblast penetration despite adherence of cells to the outer surface. These findings agree with in vivo healing studies of the same materials in the descending thoracic aorta of the dog, demonstrating that this rapid in vitro assay method can help predict the healing potential of a vascular prosthesis.