Dermodress: a new, temporary skin substitute for extensive deep burn coverage

Evaluation of speech intelligibility after a secondary dehiscence operation using an artificial graft in patients with speech disorders after partial glossectomy

The purpose of this study was to evaluate speech intelligibility after a dehiscence operation using artificial grafts for patients with speech disorders after partial glossectomy that were caused by scars resulting from the primary operation. The subjects were six men and three women, who had had a partial glossectomy for tongue cancer followed by direct closure without reconstruction. They were operated on a second time operation to mobilise the residual tongue by dividing the cicatrix. An artificial graft was applied to the wound to maintain the dehiscence. Speech intelligibility was evaluated by a standardised Japanese speech intelligibility test before, and 6 and 12 months after the second operation. The intelligibility scores significantly improved during the first 6 months after the second operation, and continued to improve slightly during the following 6 months. This study suggests that the dehiscence operation using an artificial graft could improve speech in patients after partial glossectomy.

Articulatory function in patients who have undergone glossectomy with use of an artificial graft membrane

OBJECTIVE

The purpose of this study was to investigate, by assessing speech intelligibility, the long-term usefulness of an artificial bilayer membrane as a mucosal substitute after glossectomy.

STUDY DESIGN

Artificial membranes were grafted in 8 patients with intraoral defects after glossectomy. Five patients served as a control group and received only standard closure by suture after glossectomy. Speech intelligibility was evaluated by means of a standardized Japanese speech intelligibility test 6 months or more after the operation.

RESULTS

The postoperative courses of all 13 patients were uneventful. Intelligibility scores of those who received grafts were better than those of the control group in the overall score, the glossal sounds score, and the rear portion sounds score.

CONCLUSION

The artificial membrane was useful for the glossectomy as a long-term mucosal substitute, as well as for the short-term.

Histological evaluation of skin reconstruction using artificial dermis

An artificial dermis, composed of a collagen matrix, was applied to a full-thickness skin defect prepared on the back of rats. Two weeks later, a thin split-thickness skin autograft was overlaid on the matrix at each recipient site. The dermal layer at the recipient sites was 1.02 mm thick with prior application of artificial dermis, as compared with the 0.46 mm thickness observed without such pretreatment. Histologically, the split-thickness skin graft normally lies with no gap on the artificial dermis, which looks like natural dermis. Six days after grafting, the epithelial basal cells in the grafts showed an active uptake of bromodeoxyuridine (a thymidine analogue), indicating high activity of cell proliferation. About 50 and 20% respectively of the artificial dermis remained at each recipient site at 12 and 20 weeks after its application (after the skin defect). This finding indicates that bovine collagen, which is a constituent of the artificial dermis, is gradually replaced by the host tissue.

The effects of biological wound dressings on the healing process

Three major biological dressings are available for the temporary closure of wounds: partial-thickness cadaveric human allograft skin, several forms of partial-thickness antibiotic-treated porcine xenograft skin, and human amnion. Generally, biological dressings reduce pain, close the wound to contamination and fluid loss, and prepare the wound bed for permanent closure, usually with autografts. The three types of biological dressings differ in their performance, with allograft skin being clearly superior in its wound maintenance and preparation characteristics, while porcine xenograft presents serious difficulties in incorporation into the wound bed and antigenic challenge to the recipient, and amnion is excessively fragile and tends to allow wound desiccation. The most serious potential liability of biological wound dressings is transmission of infection; however, the actual incidence of such transmission is extremely low. The advantages of physiological coverage provided by biological wound dressings greatly outweighs the chance for harm in the case of human allograft.