3.1PKD1 significantly enhanced random skin flap survival
On day three postoperative, the skin flaps in area III began to become necrotic, turn black, dry, wrinkled, and rigid. Among the three groups, the flap survival area showed significant differences. Significant changes became apparent on the seventh POD. In the PKD1 group, the survival area was larger compared to the control group (58.40±2.28% VS 76.11±0.74%, P < 0.01). Compared to the control group, the flap survival rate was significantly lower in the CID755673 group (58.40±2.28% VS 40.56±1.01%, P< 0.01) (Figure 2 A, B) .
To determine the degree of edema, the inner side of flap tissues of three groups were observed. The control group had a considerably greater water content in the flap than the PKD1 group (48.67±1.31% VS 37.83±1.33%, p<0.01), and the CID755673 group had the greatest water content (48.67±1.31% VS 58.93±1.24%, p<0.05)(Figure 2 C, D) .
The intensity of the blood flow signal was significantly stronger in the PKD1 group than in the control group on the 3rd(224.40±7.70PU VS 289.50±14.92PU, P < 0.01) and 7th PODs (346.60±10.02PU VS 431.50±21.97PU, P < 0.01). The CID755673 group is the worst on the 3rd (224.40±7.70PU VS 172.80±8.07PU, p<0.05) and 7th PODs (346.60±10.02PU VS 279.40±2.78PU, p<0.05) (Figure 2 F, G) . New blood vessels number was significantly larger in the PKD1 group than in the control group as regards the lead oxide gelatin angiography. (Figure 2 E) . Compared to the control group, all the above results were significantly worse in the CID group. Overall, the findings demonstrate that PKD1 can improve random flaps survival.