A retrospective study of 498 cases of ear surgery revealed 41, or 8.23%, labyrinthine fistulae, 33 of which were caused by cholesteatoma and 8 by a fistula related granulomatous osteitis.
Positive fistula sign was noted on only 18, or 46.5%, patients.
Seven total deafness was seen preoperatively, and in 3 the fistulae was larger than 2mm in diameter.
Incidence of postoperative sensorinerual deafness increased with the size of the fistulae. Four of the eight large size fistulae, larger than 2mm, 3 of the 9 medium size fistulae, between 1 and 2mm, resulted in sensorineural deafness, postoperatively. However, in 76.5% the hearing was preserved.
In two ears, profound deafness was noted on the 7th post-operative day and such recovered completely in about one month. Serous labyrinthitis appeared to be involved here.
In 23.7%, draining ears with fistulae progressed to sensorineural deafness, including 2 with a total deafness, postoperatively.
The following was concluded:
There is good chance of preserving hearing even with a large open labyrinthine fistula in the semicircular canal, and in cases of infected large fistula, the cholesteatoma matrix and granulation tissue should be left untouched and then removed in a second stage operation.
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