Content and distribution of collagen in venous and polyester aortal grafts

The studies were carried out on autogenous venous and polyester grafts implanted in the abdominal aorta of dogs. These grafts were excised 1,4 and 36 months after implantation and together with the normal arteries and veins, after dissection into intimal, medial, and adventitial layers, tested for their hydroxyproline and nitrogen content. It was found that the collagen content and the hydroxyproline/nitrogen ratio in the various layers of the venous and polyester grafts increased as time elapsed after the operation. The increase in collagen content was, however much higher in the polyester grafts than in the venous. The relative index of the collagen content expressed by the above ratio was found to be almost equal in the intimal and medial layers of the venous and polyester grafts 3 years after the operation and to be slightly higher than the content in the corresponding layers of the normal arteries and veins.