58.19 Grafting burns

Grafting is described in Chapter 57. All full thickness burns more than 2 cm in diameter need it. Before you can graft a burn, the dead tissue over it has to be removed. You can do this in two ways: (1) In some small deep burns you can, very occasionally, excise the wound and graft it, either immediately or in the first 3 days, as in Section 58.17. Or, (2) you can allow the dead tissue to demarcate itself, and graft the wound after desloughing, usually between the 10th and 18th day. There is thus an early and a late period for grafting, and seldom any indication to graft between the 3rd and 10th day. As a general rule, don’t delay beyond the 18th day. One of the commonest errors is not to graft early enough, or not to graft at all!

Figure 58.14: THE PRIORITY AREAS FOR GRAFTING are a patient’s eyelids, the front of his neck, his axillae, the front of his elbows, his hands, his groin, his popliteal fossae, and his ankles. His scalp, beard area, the back of his elbows, or the front of his knees have a low priority. Kindly contributed by Jack Cason.

Is the patient’s skin regenerating naturally? Don’t graft his burn if you can see that the skin is starting to regenerate. This is easy to see in a black skin—look for little greyish patches of regenerating skin at regular intervals in the depths of the burn. In a white skin, look for dull white or pink patches the size of a pin’s head or larger (’leopard spots’.)

Graft any burn where grafting might possibly help, and don’t delay merely because skin is slowly growing inwards from the edges. If you wait to allow a large burn to heal from the edges, you may have to wait a long time and when skin does finally cover the burnt area, it will be thin, pale, and more likely to become cancerous, or to break down later. Grafts take best on favourable granulation tissue (57.3), especially if this forms on the remains of the dermis. They take badly on yellow fat, and are likely to take better on the deep fascia. If granulations are favourable, a graft will probably take. If they are unfavourable, apply saline dressings (if possible three times daily), or 1% acetic acid, or hypochlorite (’Eusol’). If you are not sure the graft is going to take, be sure to mesh it.

Timing is critical. If you graft too early, you may occasionally graft unnecessarily. If you wait too long, you may find that in a few burns grafting was not necessary after all, but in most cases the granulations will be older, the graft will take less well, and the fibrosis and contractures will be worse. Make the mistake of grafting too often rather than not often enough.

When you have grafted a full thickness burn, it may look rather nice to begin with, but during the following months the scar is likely to become larger, ugly, bumpy, vascular, red, and itchy. If a patient is fortunate during the following years, it will become flatter and paler, and stop itching. If he is unfortunate, a keloid will form and grow.

GRAFTING BURNS

If skin for grafting is scarce, use it as patches or mesh (56-7), except over joints where sheet grafts will be better at preventing contractures. Place these sheets so that the joins between them go across a joint rather than along it, and thus minimize the risk of a serious contracture forming. You will use the grafts most efficiently if you leave a little space between them, because the epithelium will grow across the spaces.

If there is not enough skin to graft all a patient’s burns, give priority to the areas in Fig. 58-14, because these are the places where contractures are most likely to develop.

Skin readily regenerates from the scalp and the beard area, so these have a low priority for grafting. In practice, you will usually find yourself grafting whatever area is fit for it.

CAUTION! Never graft more than 10% of a patient’s surface area at one operation (unless you are expert and have good facilities), or he may die from hypovolaemic shock. An adult may,lose a litre of blood, or more, when you graft a 10% burn, so have blood ready. Before you graft, make sure his haemoglobin is more than 10 g/dl, and that he is not losing weight.