Generation of an autologous tissue (matrix) flap by combining an arteriovenous shunt loop with artificial skin in rats: preliminary report.

The present experiment was designed to investigate the possibility of prefabricating a tissue flap in a rat by combining an arteriovenous (A-V) shunt loop with artificial skin dermis (AS). The A-V fistula loop was constructed between the right femoral artery and vein by the interposition of a vein graft and the loop was wrapped with a folded sheet of AS and buried beneath the inguinal skin. In the control group the folded sheet of AS was inserted without a vessel loop and embedded in the inguinal region as in the experimental group. There were three experiments. In experiment 1, the total volume of the generated tissue formed within the AS was calculated after 4 weeks in the experimental and control groups. In experiment 2, the AS in the experimental group was harvested at 2 (group 1) and 4 (group 2) weeks after insertion to assess the change in morphology over time. In experiment 3, full thickness skin grafts were placed over the generated tissue of the experimental groups to investigate the possibility of creating skin flaps. The total volume of tissue generated in the experimental group was significantly greater than in the control group (P< 0.01). Histological and carbon injection studies suggest that the new capillary bed is derived from the graft loop vessels and tissue generation and organisation of the AS were further advanced in group 2 than in group 1. The skin grafts placed over the tissues generated showed complete survival and could be raised as island flaps in both groups.