An experimental study of delay phenomenon--attempts at increasing the survival length of skin flaps by use of teflon sheet.

An experiment was performed on the delay effect and flap survival in the rat. When the flap was delayed with a teflon sheet, there was greater improvement of vascularity and flap survival than in the group that was delayed without the use of a teflon sheet. INTRODUCTION Oral surgeons have been troubled by Dap necrosis occurring after the transplantation of the pedicle Dap which plays an important role in head and neck reconstructive surgery. The term "delaying a Dap" is frequently used in the field of reconstructive surgery to indicate that the Dap is being developed and transferred in more than one single stage to ensure its safety. Hypotheses with regard to the delay phenomenon so far reported can be summarized as follows: I) Delay enables tissues to be conditioned for ischemia, which makes it possible to survive on less blood flow as compared to normal need 1,2). 2) Delay improves vasculariti,4 1 in the transplanted flap. In either case, the purpose of the delay is to keep the flap alive by adapting it for a state of relative hypoxia which takes place when it is raised and transplanted. Williams (1973), who introduced a surgical technique specific for performance of delay, i.e., insertion of a sheet of silastic beneath the Dap, reported that this simple technique can fortify the delay efficacy, and that arising complications can thereby be prevented. The author et al. examined the effect of a teDon sheet inserted under the Dap upon elongation and also its role in improving the vascularity of the Dap. MATERIALS AND METHODS Sixty wistar strain male rats aged 8 weeks and weighing 260-300 gm were employed, to the dorsal part of which a single pedicle Dap sized 1.5 X 6 cm and based on caudal side was Received for Publication May 14. 1981