Labyrinthine Fistula in Cholesteatoma Patients: Outcomes of Partial Labyrinthectomy With "Underwater Technique" to Preserve Hearing

Abstract

Labyrinthine fistula (LF) is one of the most important complications of cholesteatoma and is defined as an abnormal communication between the inner and the middle ear. This study aims to describe our experience with the partial labyrinthectomy evaluating the post-operative hearing results. Twenty-one patients who presented labyrinthine fistula in the semicircular canals were included in the present study. Hearing impairment was present in 48% of patients (10/21). A pre-operative assessment using the Gardner-Robertson hearing classification showed the following: 52%, Class I; and 48%, Class II. A post-surgical Gardner-Robertson hearing classification evidenced the following: 43%, Class I; and 57%, Class II. The presence of LF is usually considered a negative prognostic factor for hearing preservation. The key point of partial labyrinthectomy surgery is the preservation of structures, keeping them wet with Ringer's solution throughout the procedures, and not performing suction that is close to the opened LF. The bony labyrinth is drilled underwater without suction, removing the entire cholesteatoma matrix and quickly plugging the site before and after the LF. This faster plugging of the labyrinth makes it possible to preserve the peri-lymph and the endo-lymph fluid and the hearing function. This study showed that a partial labyrinthectomy is useful for maintaining serviceable hearing in patients with LF.

Keywords: cholesteatoma; fistula; labyrinth diseases; otologic surgical procedure; underwater technique.

Figure 1

Female, 75 years old, intraoperative view; (A) fistula of the lateral and superior semicircular canals (asterisk) after removal of cholesteatoma matrix; (B) “underwater,” keeping wet of the membranous labyrinth with Ringer's solution and no suction; (C) labyrinth opening is closed using a bone wax (double asterisk); (D) relationship between semicircular canals fistula (double asterisk) and facial nerve (f).

Figure 2

Male, 65 years old; (A) pre-operative axial CT scan, erosion of the bony lateral semicircular canal (LSC); (B) pre-operative Coronal CT scan, a well-evident erosion of the LSC; (C) pre-operative MRI, tissue appears to encase the LSC. (D) Post-operative MRI 3D Fiesta 3D sequences (field of view 20 × 20 cm TR 4 ms; TE 2 ms; flip angle 55°); (E) post-operative images Maximum Intensity Projection (MIP) for cochlea and semicircular canal visualization, detail of operated side, showing correct visualization of endocanal fluid preservation, and meaning preservation of hearing.

Figure 3

75-year-old woman; (A) pre-operative axial CT scan showing the cholesteatomatous tissue and erosion of semicircular canals. (B) Particular coronal CT scan showing the erosion of the lateral semicircular canal, and the erosion of the tympanic tegmen; (C,D) post-operative images with MRI 3D Fiesta 3D sequences (field of view 20 × 20 cm TR 4 ms; TE 2 ms; flip angle 55°); (E) MIP for cochlea and semicircular canal visualization, detail of the operated side shows the correct visualization of the preservation of endocanal fluids. (F) MRI Coronal image with preservation of endocanal fluids, meaning preservation of hearing.

Figure 4

Male, 51 years old; (A) pre-operative axial CT scan, cholesteatomatous tissue eroding the wall of the lateral semicircular canal (LSC); (B) coronal CT scan, erosion of the LSC; (C) detail. (D) Post-operative Axial MRI 3D Fiesta 3D sequences (field of view 20 × 20 cm TR 4 ms; TE 2 ms; flip angle 55°); (E) post-operative MIP for visualization of the cochlea and the semicircular canals, detail of operated side, proper visualization of endocanal fluid showing its preservation (F,G) details.