57.4 Why grafts don’t take—infection, bleeding, anaemia, and movement

All grafts should take on a wound you have yourself made, such as one for the relief of a contracture. On burns and other potentially infected wounds there are reasons why grafts don’t take. The most important one is lack of preparation. So, prepare a wound carefully, so that you have a good chance of success. Besides preparing the granulations by the methods described just above, there are several other important factors. A graft will not take if:

(1) The wound is more than minimally infected, particularly with Strep. pyogenes. This organism secretes an enzyme which destroys the fibrin that sticks the graft to the wound. Suspect that it is present if the growing epithelium at the side of the wound has a sharp edge, instead of a normal gently shelving one. Culture a wound, and if you find Strep. pyogenes, treat it first. If you cannot culture it, give the patient penicillin routinely before grafting. Pseudomonas infection can also prevent a graft taking. Gentamicin is likely to be the antibiotic of choice.

(2) The wound bleeds as you apply the graft. A little oozing is permissable, and a graft may help to stop it, but it must be thin, and it must be covered by a firm dressing.

(3) The patient is anaemic. If his haemoglobin is less than 6 g/dl transfuse him, or give him iron before grafting.

(4) The graft is separated from the wound. So keep it closely and firmly in contact. Within 20 minutes a layer of fibrin will form and stick it there. Later, capillaries will grow through this fibrin and vascularize it.

(5) The graft is pushed sideways over the wound. For, example it will not take on an actively moving leg.

(6) The graft is stretched too tight, or it lies loose in folds, or it is pressed on too firmly. On a smooth convex surface firm bandages are enough, but on an irregular one use plenty of well fluffed out gauze, cotton wool, or plastic foam, and cover these with a crepe bandage. Don’t make the dressing too tight, especially over prominences such as the forehead, because too much pressure will stop it taking.