Prefabrication of a conjoint flap containing xenogenic tissues: a preliminary report on an experimental model.

Conjoint flaps are the compound flaps possessing multiple independent flaps, each with an independent vascular supply, but linked by a common indigenous source vessel. We have developed a new model of flap prefabrication using autogenic and xenogenic tissues in rats. Flaps were prepared at abdomino-inguinal regions of 20 male wistar albino rats. Autologous muscle, fascia, cartilage, bone grafts and acellular human dermal matrix (Alloderm, LifeCell Corp., Branchburg, NJ) were wrapped on the branches of external iliac, inferior epigastric and femoral arteries. The feasibility of prefabricating autogenic and xenogenic tissue containing flaps was investigated experimentally. Four weeks later, flaps were dissected and histopathological evaluation was undertaken. New blood vessel development was detected in all specimens with varying degrees. To our surprise, acellular dermal matrix (Alloderm), which was used as a xenogenic graft, exhibited a better revascularization potential than autogenic grafts in this prefabrication process, and a relatively dense network of new vessel formation was seen. As acellular dermal matrix is an allogenic tissue for human beings and has a superior revascularization potential, it can be prefabricated together with different autogenic tissues, and this flap can be used to reconstruct massive composite tissue defects, such as the defects occurring after tumor resection in head and neck region. With this method, donor site morbidity will be dramatically reduced. This is the first attempt of conjoint flap prefabrication using autogenic tissues combined with xenogenic tissues, which creates a new type of flap combining tissues from different species. We believe that new flap prefabrication models will be developed in the future, on the basis of this study.