Labyrinthine fistula as a late complication of middle ear surgery using the canal wall down technique

Abstract

Objectives: To evaluate the clinical features of labyrinthine fistulae occurring as a late complication of middle ear surgery using the canal wall down technique.

Study design: This was a retrospective study of the past 23 years, conducted at a single tertiary care center. The authors evaluated the backgrounds, clinical features, and surgical findings in 25 patients with labyrinthine fistulae, who had a history of ear surgery using the canal down technique and who underwent a second operation at their hospital.

Interventions: All the patients underwent revision surgery because of persistent or recurrent vertigo caused by labyrinthine fistulae, circumscribed labyrinthitis, or suppurative labyrinthitis.

Main outcome measures: The clinical features of this disease entity were assessed by history, surgical findings, and the results of audiovestibular testing.

Results: The patients had a long history of repetitive postoperative aural discharge before experiencing vertigo, which initially occurred 4 to 64 years (average, 20.2 years) after the previous operation. At the first visit to the authors' clinic, the results of a fistula test conducted with a Politzer's bulb were positive in 14 patients and negative in 5 patients. In the remaining 6 ears, pressure loading of the ear canal induced the sensation of vertigo without accompanying nystagmus. Surgical intervention showed that the fistulae were located at the lateral semicircular canal in 19 ears, at the footplate of the stapes in 4 ears, and at the promontory in 2 ears. Labyrinthine fistulae were closed with conchal cartilage, bone paste (bone dust mixed with fibrin glue), and/or temporalis fascia. In some patients, the fistulae were further covered with pedicled temporalis muscle. In 2 cases complicated by acute suppurative labyrinthitis, the mastoid cavity was obliterated after completion of the labyrinthectomy. The postoperative courses in all patients were uneventful.

Conclusions: A labyrinthine fistula may be created by repeated and insidious infection of a mastoid cavity that has been exposed to the outside during canal wall down surgery. Intensive care of the opened mastoid cavity is essential to avoid this late complication.