The purpose of this study is to demonstrate the development of angiogenesis spreading from a vascular pedicle stretched by an expander, and to determine its potential to supply blood to an adjacent skin area. In the pig model (9 animals), we inserted an expander under the saphenous vessels after interrupting all the connections between the pedicle and the related inguinal skin. The opposite side was used as a control with a non-expanded silicone sheet, 1 mm (2 animals) and 3 mm (7 animals) thick. After 6 weeks of expansion, vascular island skin flaps were elevated on the saphenous vessels. 6 out of 7 expanded flaps were totally successful. Of the 5 flaps elevated above the 3 mm silicone sheet, 1 flap was successful and 4 partially failed. The 2 flaps elevated above the 1 mm silicone sheet failed. An anatomical arteriovenous pedicle stretched by an expander can supply a skin area located distal to it. Angiogenesis also occurs in contact with a thick silicone sheet but the blood supply of the skin is less effective. The newly formed vascular network is visualized on the angiograms.