A comparison of hyaluronan and fibronectin in the healing of tympanic membrane perforations.

Fibronectin and 1% hyaluronan, two extracellular matrix components, were applied to tympanic membrane (TM) perforations, using the laboratory rat as an animal model. The perforations occupied the upper, posterior quadrant of the TM. Saline-treated and untreated perforations of equal size served as controls. Fifty percent of the perforations treated daily with hyaluronan healed prior to the first closures of the other groups. The use of fibronectin did not enhance the healing rate. The hyaluronan-treated perforations were covered initially by a sheet of keratin and hyaluronan containing abundant inflammatory cells. Within this keratin-hyaluronan cover, hyperplastic stratified keratinizing epithelium advanced and bridged the gap of the perforation ahead of the approaching connective tissue. These findings indicate that exogenously applied hyaluronan could be valuable in the clinical situation and should be tried to improve the healing of TM perforations.