Prefabricated flaps using tissue expanders: an experimental study in rats

The aim of this study was to determine if muscle vascularized pedicle flaps (MVP flaps) elevated in expanded tissue on the rat would survive to the same or greater area than flaps elevated in nonexpanded tissue. The animals were divided into three groups: group I (n = 10), with a tissue expander; group II (n = 10), with a tissue expander but not expanded; and group III (n = 10), with a thin silicone sheet (Biobrane). The mean surviving area of group I (96.6 +/- 3.6 percent) was statistically higher than that of group II (73.2 +/- 24.7 percent) (p < 0.05) and group III (59.5 +/- 25.1 percent) (p < 0.005). These experiments demonstrate that there is a larger area of flap survival in expanded muscle vascularized pedicle flaps than that found in nonexpanded flaps in rats. The mechanism of increased vascularity associated with tissue expansion is still unclear, but microangiography of flaps showed increased vascularity of the pedicle itself, especially in group I.