Deckung ausgedehnter Wundflächen durch Kombination von autogenen Netztransplantaten und fetalen Hautxenotransplantaten

Summary

In spite of acknowledged advantages for accomplishing early closure of large wounds using mesh grafts, the value of this method is limited by various disadvantages, such as continued loss of biological fluids, the lack of control of infection, and the eventual cosmetic disfigurement—which includes hypertrophic scarring. This paper discusses the use of sheets of foetal calf skin pretreated with nucleic acid to act as an immuno-suppressive agent.

Studies have been carried out over the past 20 years by various workers on the use of foetal calf skin grafts as a dressing over healing areas. In humans it has been noted that there is a surprising lack of host reaction to these grafts. The process of epithelialisation has continued extremely satisfactorily underneath them, with a marked reduction in infection of burn wounds etc.—and in the ultimate degree of contraction of the resultant scars. The use of nucleic acids appears to increase the survival time of these protective xenografts from 21.5 days to 42.5 days (Fig. 1).

Experimentally, three raw areas created on the backs of each of twelve Yorkshire pigs were covered first by mesh grafts (Fig. 2) and then by, (a) foetal calf skin pretreated with nucleic acids, (b) collagen, (c) moist saline dressings (Fig. 3). The mesh grafted defects covered with the foetal calf skin showed better healing and less contraction (Fig. 4). There was no destruction of the mesh graft and the level of the granulations was even and flat. This temporary covering remained firmly adherent until the entire area beneath was covered with epithelium, at an average time of 8 days. With the collagen sheets, the defects were epithelialised 1–2 days earlier, but contraction of the defect was appreciable. When wet dressings were used as covering material, partial loss of the mesh grafts was observed and a very pronounced wound contraction became obvious. Total epithelialisation took 10–12 days.

In an attempt to evaluate clinically the use of foetal calf skin, pretreated as described, as a possible healing adjuvant on mesh grafts, we applied this material to eleven patients with large burn wounds or skin defects following avulsion injuries. The results confirmed the animal experiments. Infection was reduced and wound healing was accelerated. The technique and clinical progress in one patient with third degree burns is illustrated (Figs. 5–10).

The combination of mesh grafts with these xenografts as a temporary coverage has proved to be remarkably useful in reducing and preventing infection and decreasing fluid loss. Healing is noticeably better beneath them, and its application stimulates markedly the growth of healthy, highly vascular granulation tissue, and thus encourages maximum take of the mesh grafts. It is apparent that the application of these xenografts serves not only as a stimulatory substance but also accelerates epithelialisation. Total epithelialisation of the interstices between the ribbons of the mesh graft was achieved between the 5th and 7th postoperative days in contrast to the usual time of between 9 and 12 days. The final appearance was improved cosmetically, and compared favourably to the use of sheet grafts. Scar formation and post-operative contraction were noticeably decreased.

Zusammenfassung

Durch Überdeckung von Netztransplantaten mit fetaler Kalbshaut, die mit Nucleinsäuren vorbehandelt war, wurde eine Beschleunigung des Wundheilverlaufes bei gleichzeitiger Verhütung von Komplikationen erzielt. Bei vergleichenden experimentellen Untersuchungen an 12 Zwergschweinen waren standardisierte Defekte nach Abdeckung mit Netztransplantaten und zusätzlicher Überdeckung mit fetaler Kalbshaut durchschnittlich 3 Tage früher geschlossen, als die mit feuchten Verbänden versorgten Netztransplantate. Unter dem Schutz des biologischen Deckmaterials war das Anwachsen der Netztransplantate sichergestellt, während es sonst zu teilweisem Verlust kam. Bei der klinischen Anwendung bestätigten sich die im Tierversuch erstellten Ergebnisse. Das Deckmaterial bewirkte eine rasche Eindämmung der Eiweiß-, Elektrolyt- und Flüssigkeitsverluste, unterdrückte das Bakterienwachstum, verhinderte überschießende Granulationen und hypertrophe Narben, womit, im Vergleich zum konventionellen Verfahren, sowohl ein besseres kosmetisches, als auch funktionelles Resultat erzielt werden konnte.