A new sealant for knitted Dacron prostheses: minimally cross-linked gelatin

There has been a resurgence of interest in the concept of presealing high-porosity knitted Dacron prostheses with an absorbable biologic material. Such a material should provide reliable porosity control, preferably reducing water porosity from 2000 ml/cm2/min to less than 50 ml/cm2/min. It should not interfere with the fibrous and vascular ingrowth that securely anchors the developing pseudointima. In previous studies, we have examined fibrin glue and two forms of aldehyde cross-linked insoluble collagen used as Dacron sealants. We concluded that delayed resorption of the sealant as seen with glutaraldehyde cross-linked insoluble collagen results in undesirable healing characteristics, particularly lack of adhesion between pseudointima and the luminal surface of a prosthesis. This study examines a new sealant. Soluble collagen (gelatin) is treated to reduce the number of free amino groups available for aldehyde cross-linking. It is then weakly cross-linked with an aldehyde mixture and applied to a knitted Dacron prosthesis. Water porosity studies have confirmed satisfactory porosity control. Both rat subcutaneous and canine circulatory implants for 6 months reveal relatively rapid and complete sealant resorption without undesirable modification of the normal healing process of knitted Dacron.