ABSTRACT
<p><b>OBJECTIVE</b>To detect the stromal cell derived factor 1 (SDF-1) expression during the survival process of the narrow pedicle flap with hypoxia and ischemia and to investigate the role of SDF-1/ CXCR4 axis in flap neovascularization.</p><p><b>METHODS</b>The narrow pedicle flaps were formed on the bilateral back of 5 pigs. The pedicle ratio of length to width was 4:2. The flap size was 2 cm x 2 cm (group A), 3 cm x 3 cm (group B), 4 cm x 4 cm (group C), 5 cm x 5 cm(group D), 6 cm x6 cm (group E). The flaps survival rate was observed and HE staining was performed. The SDF-1 expression at the distal end of flaps was detected by ELISA during the operation and 3, 5, 7, 14 days after operation.</p><p><b>RESULTS</b>(1) SDF-1 expression at the same group increased after operation until it reached the peak value at 5 days after operation; then it decreased to basic value. (2) SDF-1 expression in different groups was higher in bigger flaps until the flaps size reached 5 cm x 5 cm. Then partial necrosis happened at the distal end of flaps.</p><p><b>CONCLUSIONS</b>The SDF-1 expression may be related to the blood supply during the survival process of the narrow pedicle flap with hypoxia and ischemia.</p>