A new mechanism associated with compositae graft success.

It is believed that the subcutaneous fat of the skin compositae grafts acts as a mechanical barrier limiting vascularisation. This study aims to determine a new mechanism associated with compositae graft take. Ten 3×3 cm rectangular full-thickness skin compositae grafts on the back of a pig were taken and then randomly changed to another place. Silicone sheets were then inserted between the graft and the recipient to block the direct contact of the dermis at the lateral surface of the graft and control the number of surface contacts. The take rate was measured using the digital VISITRAK(®). The microcirculation of the graft was evaluated by microangiograms using a latex-lead oxide solution. There was a 20.5% graft take in all four surface-blocked groups. The microangiograms showed vessel connections not only between the vessels of the dermis, but also between the subcutaneous fat of the graft and perforators from the basal surface of the wound. The subcutaneous layer does not produce a barrier but works as a significant source of vessel communication. Direct vessel-to-vessel anastomosis between the vessels of the subcutaneous fat at the graft and the basal surface of the recipient wound are another important mechanism for the success of compositae grafts.