Annals of the MBC - vol. 3 - n' 2 - June 1990


Dayoub A.

Faculty of Medicine, Aleppo University, Syria

SUMMARY. The are two main ways of removing the eschar that forms after third-degree bums: spontaneous separation (including removal by medication) and surgical separation. Both methods are equally valid in clinical practice, and neither is to be preferred to the other as a matte r of principle. The two techniques are described.

Treatment of third-degree eschar

The treatment of third-degree burn wounds includes the removal of the eschar and transplantation of skin. In this paper the problem of removal of the eschar is discussed. In principle, there are two ways of removing the eschar: by spontaneoLus__~eparation (including removal by medication) and by surgical measures. In clinical practice, we should use both methods, without favouring one and neglecting the other.

Fig. 1 Fig. 2
Fig. 1 Fig. 2
Fig. 3 Fig. 4
Fig. 3 Fig. 4

Spontaneous separation of eschar by "silkworm bite"

After the self-dissolved necrotic tissue of third-degree eschar is separated from the new growth of granulation tissue, the already separated and loosened eschar should be scissored off immediately. The manoeuvre must be conducted gently, so as to avoid bleeding if possible.
If the granulation tissue appears fresh and healthy after the casting-off of the eschar, grafting

  • using small stamp-sized autografts
  • should be performed immediately to cover the wound surface, even if some remains of necrotic tissues are still present.

This is due to the fact that at this time the ability of the wound to accept skin graft is at its maximum; delay may cause a valuable opportunity to be missed. The longer the granulation tissue is exposed, the greater is (a) the chance of infection and (b) general debilitation. Therefore, after the eschar has been cast off, the principle of "grafting as much as possible" should be adopted to ensure that the wound is covered with autografts or allografts in time. In the case of extensive bums, coverage with skin should be done as soon as the granulating wounds are exposed.
Since all granulation tissue is infected, culture for bacteria will always be positive; there is therefore no need to wait for a negative culture before skin is grafted. Generally speaking apart from haemolytic Streptococcus and haemolytic Staphylococcus aureus, no other bacterium influences the take of skin grafts. Nevertheless, if the wound is seriously infected with the presence of large quantities of purulent exudate unfavourable to the take of the skin grafts, then before skin grafts are transplanted one should treat the wound (usually for 1-3 days) until the local infection is adequately controlled.
In the case of more extensive and deep third-degree bums, removal of a large area of eschar all at once would be liable to induce sepsis.

Fig. 5 Fig. 6
Fig. 5 Fig. 6
Fig. 7 Fig. 8
Fig. 7 Fig. 8

One should therefore protect one part of the eschar while causing another part to separate earlier. To "protect" the eschar means to protect its integrity and dryness, and to minimize pressure bearing. On the other hand, to promote the separation of the eschar, the best technique is to moisten it.
In order to secure immediate coverage in extensively burned patients after spontaneous separation of the eschar, numerous operations are needed. However since the time required for each operation is short and no deep anaesthesia is necessary, patients usually come through the operations quite well. Sometimes it is not necessary to wait for complete separation of the third-degree eschar, since debridement may be done when the patient's condition permits. Between the 2nd and 3rd week after injury, when there is already a new growth of granulation tissue under the eschar, we place the patient under general anaesthesia and "help" to separate the eschar by trimming the wound with scissors or a knife. Skin grafting may be done after use of wet dressing or bandaging until the necrotic tissue further casts away (after 2-3 days). Debridement, however, must be avoided before the eschar has the tendency to separate spontaneously, the reason being that at this time its base is formed by necrotic tissue, and skin grafting cannot be performed within a short period after debridement. Moreover, the ability of adipose tissue to resist infection is weak; consequently it is liable to be infected when exposed and serious consequences may ensue.


Escharectomy is a very effective method of eschar removal. The result is cosmetically superior to wounds which have been treated by excision to the fascia and in selected cases significantly shortens hospital stay and hastens rehabilitation. It may be used at the primary modality of therapy or as an adjunct to conservative therapy.
Blood loss can be excessive if extensive areas of eschar are removed. No more than 30% of the body surface should therefore be subjected to the procedure at one time. It may also be necessary to repeat the procedure several times, as not all non-viable tissue may be removed during the initial operation.

Fig. 9 Fig. 10
Fig. 9 Fig. 10
Fig. 11 Fig. 12
Fig. 11 Fig. 12

Eschar excision

For deep third-degree bums, excision of the eschar in combination with skin grafting may be used. It is possible to cover the wound at an earlier date, thereby shortening the course of treatment and avoiding various complications. For third-degree bums located in the hand or functional parts of the joints, after eschar excision and grafting of large sheets of skin, contracture may be reduced to a minimum and recovery of function is satisfactory. Comparatively speaking, this is therefore an ideal method.

Fig. 13 Fig. 13


The timing of excision should be determined by the patient's general condition, the total burned area, and the extent of third-degree burn.

  1. For minor bums with small third-degree burns, third-degree eschar may be excised immediately after injury if the general condition of the patient permits.
  2. For extensive burns with third-degree burns, it is necessary to wait until the patient has smoothly passed the shock stage before excising the eschar. Eschar excision may be done 3-14 days after injury.

The time of the first excision operation should, as a rule, be about 5 days after injury, when the patient has already passed the shock stage and is in a relatively stable condition, and oedema has essentially been reabsorbed.

Size and location of excision

As to the selection of locality, as a rule the extremities are chosen first and the trunk of the body afterwards, the principal reasons being:

  1. On the extremities, eschar excision may be performed with the use of a tourniquet, so that there is only a small amount of bleeding and the operative procedure is easy.
  2. Burns of the extremities are often deeper than those of the head and trunk, and may be accompanied by muscular necrosis or even charring of the limb involved. These complications should be treated at the same time.

The interval between two excisions

As a rule, the interval is about 3 days, if the general condition of the patient is stable, in which cAe it may be suitably shortened. It is necessary to make good use of the 2 weeks post-bum for operations, since this is the most opportune time.

RESUMÉ. Il y a deux méthodes principales pour décoller l'escarre qui se forme à la suite des brûlures de troisième degré: la séparation spontanée (y compris la séparation médicale) et la séparation chirurgicale. Toutes les deux techniques sont valides dans la pratique clinique, et il ne faut pas préférer l'une ou l'autre par principe. L'Auteur décrit les deux méthodes.


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