ABSTRACT
<p><b>OBJECTIVE</b>This study was to develop a new method that can improve flap survival.</p><p><b>METHODS</b>A long skin flap spanning the full length of the rat dorsum was used to make a bilateral skin tube, which was based on the lateral thoracic artery proximally, and the deep circumflex iliac artery distally. The animals were randomly divided into 3 groups of 8 rats in each group: the control and two experimental groups with elevation of the tube (the proximal pedicle divided) immediately or 24 hours following ischemic preconditioning. All tube flaps were observed for 3 days postoperatively and the surviving flap area was measured as a percentage of the whole flap using the paper template technique. Heat shock protein 70 in the three groups was examined by means of immunohistochemistry.</p><p><b>RESULTS</b>There was an overall statistical significance in comparison of flap survival of the preconditioned flaps with that of the controls. There was no statistical significance between the two preconditioned groups. Heat shock protein 70 (HSP70) was demonstrated immunohistochemically in the preconditioned skin flap but not in the control skin flap.</p><p><b>CONCLUSION</b>Ischemic preconditioning can improve skin flap survival and the contents of HSP70. It is suggest that the mechanism be related to the function of HSP70.</p>