Polyester Arterial Grafts Impregnated with Cross-Linked Albumin: The Rate of Degradation of the Coating in vivo

Abstract

One of the techniques used to avoid preclotting a porous textile arterial prosthesis is to coat the graft with a layer of a bioerodible polymer. The efficacy of this treatment is dependent in part on the rate at which the polymer degrades after implantation. The focus of this study was therefore to investigate the rate of in vivo degradation of albumin-coated polyester (Dacron)-knitted vascular prostheses. Two types of cross-linked albumin were included: one using glutaraldehyde, the other using carbodiimide as the cross-linking agent. Radioactively labeled albumin-coated prostheses were implanted in the thoracic aorta and peritoneal cavity of dogs, and their rates of biodegradation in vivo were monitored over a 4-week period. The rate of biodegradation was found to depend upon the site of implantation. It occurred more rapidly in the peritoneal cavity where less than 20% of the albumin coating remained after 4 weeks in vivo in comparison to the approximately 30% in the thoracic aorta. The nature and intensity of the cellular response appeared to be related to the cytotoxic potential of the cross-linking agent. Glutaraldehyde induced an inflammatory response and a delay in healing, whereas carbodiimide caused only a mild tissue reaction.

In vivo Evaluation of Polyester Arterial Grafts Coated with Albumin: The Role and Importance of Cross-Linking Agents

“…We have previously reported that the in vivo rate of bioerosion of cross-linked albu min-coated prostheses varies with the site of implantation [4], This paper extends the scope of this previous work by evaluating the in vivo rate of bioerosion and the healing sequence of albuminated prostheses crosslinked by three different protocols. The ef fect of two different concentrations of glutaraldehyde (GTA) and the effect of carbodiimide (CDI) cross-linking agents were in vestigated by implanting albuminated or preclotted (control) polyester (Dacron®) grafts into the canine aorta for scheduled periods ranging from 4 h to 6 months.…”

“…By employing in vitro and in vivo tests it has been possible to demonstrate that this rate of albumin degradation de pends on both the type of cross-linking agent as well as the site of implantation [2,4], In pancreatin solution, the CDI cross-linked al bumin degrades faster than the GTA crosslinked device. However, when implanted in the peritoneal cavity of the dog, both types of cross-linked albumin degrade more rapidly (more than 80% in 4 weeks) than when im planted in the canine thoracic aorta (where about 70% degrades over the same period).…”

“…(b) Immunocytochemial staining was conducted as described previously [4], The slides were exposed to a dilute solution of a specific rabbit antiserum against human-factor-VIlI-related antigen (Hoechst Canada Inc., Montreal, Que., Canada), incubated for 2h at room temperature, washed in Tris buffer and then reincubated with a dilute solution of peroxidase- conjugated goat antirabbit globulins (Hoechst). After repeated washing, the final exposure was to a solution of 0.05% diaminobenzidine hydrochloride (Sigma) and 0.01 % hydrogen peroxide (Anachemia Chemicals Ltd., Montreal, Que., Canada) in 0.05 M Tris buffer at pH 7.6 for 10 min.…”

Evaluation of the healing of precoated vascular dacron prostheses

“…Finally, all albumin-coated grafts displayed a chronic inflammatory periprosthetic reaction. The probable reason for the failure of graft incorporation was the pretreatment of albumin with glutaraldehyde [4].…”

Impregnated Polyester Arterial Prostheses: Performance and Prospects

“…101,102 It was less pronounced when albumin, whose bioresorption is more rapid, was used. 103 It did not seem to be related to the cytocompatibility of albumin or to the release of glutaraldehyde during bioresorption. [104][105][106] An evaluation of healing activity in other animal models confirmed this healing delay as well as the nonreproductibility of the resorption rate.…”