Use of lyophilized dura in aural surgery.

Lyophilized dura was utilized in chronic ear surgery to cover raw promontory surfaces, to stabilize the reconstructed ossicles, to raise the posterior insertion point of the grafted drum after canal wall removal, and to fortify the soft posterior canal wall. In 3 guinea pigs, lyodura was also placed in the bulla and studied 6, 12 and 16 months later. In 6 months of time, lyodura had become covered with normal epithelium and in 12 months of time, the greatest part of the lyodura was resorbed from the middle ear, normal epithelium having developed. In the canal wall area, resorption is slower and collagenic dural network is clearly recognizable even after a period of 24 months. Lyophilized dura contains no irritating material and is considered to be a versatile and useful material in chronic ear surgery.