McGreagor and Morgan described traditional classification of axial and random pattern flap in 1973. This classification was reported based on the vascularization of flap blood supply. In 1981 fasciocutaneous flaps were first described and are still used today because they have the ability to stabilize the blood flow in the flap. Recently, new types of surgical flaps such as thin flaps have been used to avoid secondary operation of defatting. There are some reports about thin flap using LDflap (Latsimus Dorsi flap), ALT flap (Antero Lateral Thigh flap) and DIEP flap(Deep Inferior Epigastric Perforator flap). Although skin graft has been widely used for skin defect, it sometimes causes scar contracture after the operation. Thin flaps are not only useful to plastic surgeons but also useful to any other surgeons to reconstruct the skin defect of the hand, optical cavity, bone exposed area and so on. We operated on several cases of pressure sore by using S-GAP flap (supra-gluteal artery perforator flap) and had fine results. In the future, thin S-GAP flap is also useful to the ulcer, dermatitis and burn scar contracture in stead of skin grafts.  

• The purposes of this study are:
  
• To investigate intrinsic blood supply of thin gluteal flap.
  
• To examine their vascular territory and supra & infra gluteal perforator vessel locations and their diameters, lengths, branches
  
• To identify the anatomical landmark compare with the location of perforator vessels.