Objective: To study the clinical feature and surgical management of labyrinthine fistula caused by chronic suppurative otitis media (CSOM).
Method: A retrospective study of 450 patients with CSOM who underwent radical mastoidectomy between the years 1992 to 1999 in Department of Otolaryngology, Xijing Hospital was conducted.
Result: 20 patients (4.4%) with labyrinthine fistula caused by CSOM were found. The average history of ear drainage was 22 years, 18 patients (90%) had subjective hearing loss, and 13 patients (65%) had dizziness. The fistula test was positive in 9 patients (45%). 2 patients had anacusis in the affected ear. The preoperative pure tone average for bone conduction thresholds was less than 30 dB in 11 patients, between 31 and 50dB in 3 patients, and more than 51 dB in 4 patients. The ears with a positive fistula test had worse preoperative hearing than those with negative test (P < 0.01). The fistula was detected by CT in 2 of 9 patients. Cholesteatoma was present in 18 patients (90%) and granulation tissue was present in 2 patients (10%). The lateral semicircular canal was the site of labyrinthine fistula. The lesion at the site of fistula was completely removed in 17 patients and exteriorized in the remaining 3.
Conclusion: There are no reliable methods at present for preoperative diagnosis of labyrinthine fistula, ultimately, the most reliable way to identify a fistula is during surgery. The method of manipulation of labyrinthine fistula is based on the concrete conditions of fistula and patient.