The simplest wound to leave a flap is a ’V’ – shaped laceration. The apex of the ’V’ is likely to necrose, so try to replace it without stitching, and warn the patient that healing may be delayed. If a stitch does seem necessary, use the apical stitch in Fig. 54-8.
With larger flaps, you can do three things: (1) You can replace a flap. (2) You can excise and discard it. (3) You can excise it and use it to make a graft. When you treat a wound with a flap you have two decisions to make. Firstly, should you keep the flap? Secondly, what should you do with the fat under it?
Replace a flap if: (1) Its edges bleed. (2) It becomes pale when you press its base and pink again when you let it go. (3) Its base is wider than its length. And, (4) the wound under it is clean. Otherwise, excise it. If you decide to keep it, hold it in place with adhesive strapping rather than sutures.
Fat impedes the diffusion of nutrients from the surface of a wound to the overlying skin of a flap. So trim off any obvious lumps of fat from under a flap as in Fig. 54-9. If a flap is very thick, trim it so that it has a thinner margin and a thicker base which preserves its blood vessels. Make sure that: (1) the patient does not lie on it, and (2) it is uppermost, if it is very thick, so that gravity keeps it in place.