Transplantation of autologous oral mucosal epithelial cell sheets inhibits the development of acquired external auditory canal atresia in a rabbit model.

ABSTRACT

Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, hearing loss and chronic otorrhea. Although the disease can be treated surgically, the recurrence rate is high. This study explored whether autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. We succeeded in generating a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Endoscopic and histological findings in this model indicated that atresia developed over a 4-week period and was not inhibited by the placement of polyglycolic acid sheets immediately after skin dissection. By contrast, transplantation of autologous oral mucosal epithelial cell sheets, which had been fabricated by culture on temperature-responsive inserts without a feeder layer, prevented the development of atresia during the 4-week period after skin dissection. Transplantation of autologous epithelial cell sheets after surgical treatment of acquired external auditory canal atresia could be a promising new method to reduce the risk of disease recurrence. STATEMENT OF SIGNIFICANCE: Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, which leads to hearing loss and chronic otorrhea. Although surgical treatments are available, the recurrence rate is high. In this study, we successfully generated a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Furthermore, we utilized this new animal model to investigate whether the transplantation of autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. Our results raise the possibility that the transplantation of autologous epithelial cell sheets after surgical treatment of ear canal atresia could be a promising new method to reduce the risk of disease recurrence.