Integra acellular collagen as a vascular carrier for skin flap prefabrication in rats

In this study, the feasibility of Integra acellular collagen used as a vascular carrier in skin flap prefabrication was examined. In all, 20 Sprague--Dawley rats were randomly divided into 3 groups. The saphenous vascular bundle was used as the vascular carrier. In group 1 (n = 8), an arteriovenous fistula was made by anastomosis of distal saphenous artery and vein. An Integra patch (2 × 3 cm²) was placed underneath the vascular bundle. In group 2 (n = 6), an Integra patch was placed on the top of the saphenous vessels, which remained intact. In group 3 (n = 6), an arteriovenous fistula was made without Integra implant. Two weeks after the initial management, a skin flap (2 × 3 cm² in size) was raised and replaced in each group. The survival of the flaps and histology were evaluated at 7 days after flap replacement. The results showed that the average survival area in group 1 was 98% ± 2%. No flap survival was observed in group 2. The mean survival area in group 3 was 29% ± 6%. The differences among all 3 groups were significant (P < 0.05). Although the mean survival area in group 3 was significantly lower than that in group 1 (P < 0.001), it was significantly higher than that in group 2. Histology showed that the Integra patch was incorporated into the adjacent connective tissue, and increased amounts of neovascularization were seen between the collagenous sheets and dermis in group 1. In conclusion, this study demonstrated that Integra acellular collagen can incorporate into the adjacent tissue as a vascular carrier and induce angiogenesis in flap prefabrication. This biomaterial can provide a scaffold for supporting and enhancing the survival of a vascular prefabricated skin flap. The results indicate that this material is an ideal biomaterial for flap prefabrication and may be used for this clinical purpose in the future.