“…Following the concept of therapeutic angiogenesis, 37 several factors, including transforming growth factor, basic fibroblast growth factor (bFGF), and VEGF have demonstrated marked abilities to improve skin flap survival 17,18,24 . Experimental studies have demonstrated that administration of exogenous VEGF can induce flap angiogenesis, improve the survival of random extensions of axial‐pattern skin flaps, and accelerate flap prefabrication 11,24 . The half‐life of VEGF protein under normal conditions is approximately 30–45 minutes, but this biological activity increases to 6–8 hours under ischemic conditions 38,39 .…”