Prefabrication of composite tissue for improved tracheal reconstruction

Tracheal repair tissues were evaluated experimentally to provide an evidenc e-based choice for decision-making in clinical tracheal reconstruction. Tra cheal reconstructive tissue was characterized as providing for vascularizat ion, support, and/or lining. A tissue equivalent was developed in the rabbi t for each of the individual tissues. The individual tissues consisted of n onepithelialized soft tissue (vascularized fascia), epithelialized tissue ( vascularized fascia grafted with buccal mucosa), and supportive tissue (ear cartilage). The 3 reconstructive tissues were evaluated in 30 rabbits afte r repair of an anterior laryngotracheal defect. Morphometric and histologic analysis was applied to the reconstructions. After a 1-month follow-up per iod, defects repaired with nonepithelialized soft tissue showed healing by secondary intention and a wound that was contracted to 44% of the initial s urface area of the defect. Mucosa-lined soft tissue flaps and cartilage gra fts showed a less than 10% wound contraction. Compared to cartilage grafts, mucosa-lined soft tissue (vascularized fascia grafted with buccal mucosa) seemed preferable for clinical use, because it showed healing by primary in tention. A mucosa-lined radial forearm fascia flap was used successfully in cases of restenosis after tracheal resection. One deficiency of the mucosa -lined soft tissue was the absence of supportive tissue. In cases of extens ive stenosis, it might be useful to obtain additional expansion of the airw ay lumen by creating a convexity at the site of reconstruction. In a second set of experiments, we attempted to improve the mucosa-lined soft tissue c oncept by adding elastic cartilage. A composite tissue consisting of vascul arized fascia, buccal mucosa, and auricular cartilage was developed. Hetero topic prefabrication of the composite tissue was essential for survival of the cartilaginous component. Additional airway lumen expansion could be obt ained after heterotopic flap prefabrication. After experimental evaluation, the concept of the prefabricated composite tissue was successfully applied in a clinical case of long-segment stenosis. Experimental and clinical evi dence suggests that the combination of buccal mucosa and fascia form an opt imized tissue combination for tracheal reconstruction. This combination can be improved by adding strips of autologous ear cartilage.