Silver acetate coating promotes early vascularization of Dacron vascular grafts without inducing host tissue inflammation

BackgroundSilver acetate is frequently used as an antimicrobial coating of prosthetic vascular grafts. However, the effects of this coating on the early inflammatory and angiogenic host tissue response still remain elusive. Therefore, the aim of the present in vivo study was to analyze the biocompatibility and vascularization of silver acetate-coated and uncoated vascular grafts during the initial phase after implantation.MethodsTwo different prosthetic vascular grafts (ie, uncoated Dacron and silver acetate-coated Dacron Silver) were implanted into the dorsal skinfold chamber of C57BL/6 mice (n = 8 per group) to study angiogenesis and leukocytic inflammation at the implantation site by means of repetitive intravital fluorescence microscopy over a 14-day period. At the end of the in vivo experiments, collagen formation, apoptosis, and cell proliferation were analyzed in the newly developed granulation tissue surrounding the implants by histology and immunohistochemistry.ResultsDuring the initial 14 days after implantation, Dacron Silver exhibited an improved vascularization, as indicated by a significantly increased functional capillary density compared with Dacron. This was not associated with a stronger leukocytic inflammatory host tissue response to the implants. Moreover, silver acetate coating did not affect collagen formation, apoptosis, and cell proliferation at the implantation site.ConclusionsSilver acetate coating of prosthetic vascular grafts improves their early vascularization without inducing severe inflammatory side effects. Accordingly, this material modification crucially contributes to an improved incorporation of the implants into the host tissue, which may decrease the risk of vascular graft infection.

Clinical RelevanceScientific findings about tissue integrity of antibacterial coated vascular grafts are lacking. A risk factor for prosthetic vascular graft infection seems to be a contamination before complete incorporation of the implant. Angiogenesis is a mandatory process for incorporation and biocompatibility of synthetic materials. It is an integral factor in determining the success or failure after implantation in general of alloplastic material. However, the integrity of silver acetate-coated vascular grafts still remains unknown. Therefore, it was the aim of our study to investigate angiogenesis and inflammation of silver acetate-coated polyester vascular grafts compared with uncoated grafts in an experimental model.