Random-Pattern Skin Flap Model
The back hair was removed, and all rats were intraperitoneally anesthetized with 40 mg/kg of 2% (w/v) sodium pentobarbital. By cutting the skin along a specified line (3cm × 9cm), random skin flaps were created. The skin was cut along the design line, and the skin flap underwent entire separation from the deep fascia. The bilateral sacral arteries were cut off and finally sutured in situ intermittently with 4-0 sutures. Each flap had three equal zones: zone I (proximal), zone II (intermediate), and zone III (distal) (Figure 1 ).