Two-stage transplantation of cell-engineered autologous auricular chondrocytes to regenerate chondrofat composite tissue: clinical application in regenerative surgery.

Background: The authors have developed a unique multilayered culture method that expands to large volumes elastic chondrocytes from a small piece of human auricular cartilage. In this study, the authors applied the two-stage transplantation method for cultured auricular chondrocytes to difficult cases of nasal/chin reconstruction where subcutaneous tissue is thin or scarred.

Methods: Auricular chondrocytes were cultured and expanded to sufficiently large volumes, and then, in a two-stage transplantation process, injection-transplanted into a patient's lower abdomen, where they were regenerated into larger chondrofat composite tissue in 6 months and used as a material for nasal/chin reconstruction. The authors then performed histologic and electron microscopic analysis of serial cross-sections and magnetic resonance imaging analysis of the chondrofat composite tissue.

Results: The cultured auricular chondrocytes consistency regenerated intraabdominally to a larger, stable neocartilage, with adherent fat tissue within 6 months. Eighteen patients (nose, n = 14; chin, n = 4) underwent this procedure, and the chondrofat composite tissue was stable after 1 to 5 years' postoperative follow-up. The chondrofat composite tissue maintained good shape, with no major complications. Magnetic resonance imaging showed that the chondrofat composite tissue was regenerated and vascularized in the abdomen in all 18 cases (100 percent). Infection and total absorption were not seen. Only partial absorption was noted (5.6 percent).

Conclusions: The chondrofat composite tissue was found to be a new innovative graft material in which neocartilage is regenerated to be continuous with fat tissue by means of the neoperichondrium. It has thereby become possible to perform the previously impossible simultaneous reconstruction of cartilage and fat tissue.