Second step. The flap is marked out at least one-third larger than the size required to cover the raw area. The base of the flap should be placed a little below the raw area to be covered, so that the rotation of the flap into position is easily performed without danger of constriction to the base (Fig. 158).
Third step. The flap having been raised and all bleeding stopped, it is rotated and sutured in its new position, the wound made by the removal of the flap being brought together by sutures or, if it be too large for this, covered by skin grafts (see Vol. I, p. 670).
BY THIERSCH’S SKIN-GRAFTING METHOD
Indications. As has already been pointed out, this method is not so satisfactory as the method by flaps described above, but it is frequently the only one available when the surrounding skin has been destroyed, as after extensive lupus of the face.
Instruments. Scalpel, forceps, skin-grafting razor, probes.
Operations. First step. As for the previous operation.
Second step. Grafts are cut from a situation free from hairs, such as the inner side of the upper arm (see Vol. I, p. 671).
Third step. After all bleeding has been stopped, the grafts are applied, straightened with probes, and pressed firmly down on to the raw surface. The edges of each graft should slightly overlap the one next to it. Great care should be taken in applying the dressings not to disturb the grafts (see Vol. I, p. 673).
If the whole thickness of the skin be used (Wolff’s method), care should be taken to see that the under surface is free from fat.