Treatment of full skin thickness burn injury using cultured epithelial grafts.

This report presents the experience gained from 26 patients treated with autogenic cultured epithelial grafts (auto-CEG). All auto-CEG were applied to wounds clinically defined as full skin thickness injury. In total 89 separate sites were grafted. The overall estimate of 'take' ranged from 0 to 98 per cent with a mean value of 15 per cent. The highest level of 'take' (43 per cent) was observed when auto-CEG were applied to wounds which had been previously covered with allogenic split-thickness skin grafts. An increased incidence of wound colonization with pathogenic species of bacteria corresponded with a decreased graft 'take'. Ps. aeruginosa and Staph. aureus were found to be present on 32.6 per cent and 60.5 per cent of wound swabs respectively, where 10 per cent or less 'take' of auto-CEG was seen, indicating that bacterial infection is in part responsible for graft failure. However, in 20.9 per cent of such instances, no growth of bacteria was detected, perhaps suggesting that certain wound beds may not present the correct physical environment necessary to support proliferating epithelial cells isolated from their underlying dermal component.

Implications for would healing of patient age and time elapsed since burn injury.

To determine the relationship between growth potential in culture and the age of the patient, skin biopsies were obtained from over 60 patients of varying ages. The relationship between the length of time elapsed since burn injury and growth potential was also examined, using biopsies obtained from patients with burns during their treatment. Keratinocytes were extracted from biopsies and assessed for colony-forming ability by standard methods. Repeated subculture of cells was undertaken to determine the reproductive capacity of cells in vitro. Age had no effect on the colony-forming ability of keratinocytes in primary culture; however age did affect the total number of generations achieved by these cells. The growth potential of keratinocytes from patients with severe burns showed considerable variation according to the amount of time which had elapsed since the injury. This was most apparent around one week post-burn. These results need to be investigated further to understand their clinical implications. The study provides an insight into the influence of age and physiological response on the wound healing process in burn injuries.

The treatment of donor sites with cultured epithelial grafts.

In a significant number of elderly patients, the healing of split skin donor sites can be delayed. The cultured allogenic epithelial graft (CAG) has been reported to heal leg ulcers. The mechanism of action may be to improve the healing environment and thus stimulate the host skin cells. A clinical trial was undertaken to compare the healing rate of the donor sites of elderly patients using CAGs and two commercially available dressings. Compared to Jelonet, CAGs (p = 0.008) and OpSite (p = 0.013) significantly reduced the number of patients with delayed healing. There was no significant difference between CAGs and the occlusive dressing, OpSite.