Labyrinthine Fistula and Tympanoplasty

Abstract

Three interdependent problems have to be solved by a surgeon in each case of middle ear cholesteatoma with a fistula of the horizontal canal: 1) Whether the matrix can be safely removed from fistula or should be left in place; 2) if the matrix is removed, whether the fistula should be covered or not and, in the positive case, by which kind of graft; and 3) whether closed or open tympanoplasty should be performed. In well selected cases the matrix can be safely removed from the fistula and some technique of closed tympanoplasty used. Suitable for this type of surgery are cases of superficial fistula of the horizontal canal, with preservation of the endosteal membrane, where complete removal of the matrix from the tympanic cavity is possible. Very poor hearing and obvious middle ear infection are apparent contraindications. Furthermore, this type of surgery should not be performed on a better hearing ear. If any difficuty in removal of the matrix from the fistula is encountered, the matrix should be left in place. Fistula cases which do not fulfill these criteria should be treated either by open tympanoplasty or by modified radical mastoidectomy, leaving the matrix on the fistula. A small series of five consecutive fistula cases treated by closed tympanoplasty, using intact wall technique or reconstruction of the bony canal wall, with removal of the matrix from the fistula, leaving it bare, is reported after a follow up of three to six years. The results indicate that, in selected fistula cases, this type of surgery seems to bring favorable late hearing results and to create good conditions for closure of the fistula, apparently not presenting any risk to the inner ear.