Biocompatibility of silver-coated peritoneal dialysis catheter in a porcine model

Abstract

Objective: Previous studies have shown that silver formulations coated onto implantable materials retard bacterial colonization and reduce the incidence of catheter-related infections. The objective of this study was to assess the histologic effects of sputter-coated silver/ silicone implants on host tissue.

Design: Sputter silver-coated silicone peritoneal dialysis catheter segments with and without Dacron cuffs were implanted in the subcutaneous fat and muscle in 4 pigs. Noncoated implants served as controls. The specimens were retrieved at 1, 2, 3, 4, 7, 8, 9, 10, 12, and 27 weeks.

Experimental animals: Four 6-week-old male Yorkshire-Landrace pigs (5-6 kg) were used.

Main outcome measures: Histologic parameters evaluated included the degree of inflammation, the number of giant cells, the extent of silver particulate inclusions, and the thickness of the capsules. All specimens were evaluated by a single blinded pathologist. Microbiologic analyses were also performed.

Results: The silver-coated catheters were associated with less inflammation than were the noncoated catheters, both in fat and muscle (p = 0.04). The number of giant cells was also lower around the silver-coated than the non-coated catheters, which were implanted in subcutaneous fat (p < 0.05). Particulate inclusions compatible with silver or silver oxide were observed only in tissue around silver-coated implants (p < 0.0001). The thickness of the capsules and the extent of the inflammatory zones were not significantly different. There was no evidence of infection-related changes.

Conclusions: These data suggest that the sputter silver coating does not act as a significant tissue irritant.