Fig. 5. Sandwich Grafting Technique. A Full thickness burn back; B Following excision and application 4:1 Autograft with 2:1 allograft overlay; C Allograft separated, autograft taken, interstices epithelialising; D Healed wound

is applied. This is usually done in stages on a weekly basis until the whole wound is closed with autograft.

Serial excision

A more traditional conservative surgical approach has been described above for deep partial thickness burns and entails excision of as much of the wound that can be covered with available autograft. The unexcised areas of burn are treated with topical antimicrobials until the donor sites are ready to be reharvested. This method of treatment has a higher morbidity and mortality in larger injuries and has generally been abandoned in the author’s service but is still popular worldwide and is indeed the standard of care in many institutions.

Topical antimicrobials and autografting of a granulating wound used to be popular but in general has been abandoned for more aggressive surgical approaches described above.

It is only suitable for smaller burns in patients who are unfit for surgical debridement of the burn wound. It is not recommended for younger, fit patients with larger injuries.

Mixed depth burn

Although the descriptions above have described specific depths of burn, in clinical practice most burns are mixed depth with areas of superficial partial, deep partial and full thickness injury in adjacent area. Treatment of such wound depends on the mixture of each component part of the injury, as one will usually predominate. In general superficial partial thickness areas should be left to epithelialize while the areas of deeper injury require excision and wound closure.

Donor sites

Pre-operative planning is essential prior to burn surgery. In particular choice of donor sites to be used, anatomical areas to be debrided, and the technique used for debridement. It is essential to estimate the amount of autograft that will be required, which areas are priorities for autograft coverage and any required mesh ratios.

In smaller burns where donor sites and available graft is plentiful, the focus is to minimize donor site morbidity and to maximize functional and cosmetic outcome. Sheet grafts are preferred and care must be taken to preferentially harvest cosmetically hidden areas such as the upper thighs, buttocks and scalp. In young females skin should be harvested from either the buttock or the upper inner aspect of the thighs. In young males the upper outer aspect of the thigh can be used in addition. The scalp is an attractive donor site, as subsequent hair growth completely hides the scars.

In patients with major burn injury choice of donor sites is limited and skin grafts should

be harvested from any available site as priority is given to cover large areas with available autograft in the smallest number of operations.

Techniques of wound excision

It is accepted that removal of necrotic devitalized tissue saves lives and is key to wound healing and closure. The technique used to excise the burn wound depends on the depth and extent of injury. Preserva-