Underwater Endoscopic Ear Surgery for Closure of Labyrinthine Fistula with Preservation of Auditory Function

Honkura, Yohei1; Yamauchi, Daisuke1; Shimizu, Yuichi1; Sunose, Tomoki2: Hara, Yosuke1: Ohta, Jun1; Suzuki, Jun1; Kawase, Tetsuaki3; Katori, Yukio1

1Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Miyagi, Japan;
2 Department of Otolaryngology, Osaki City Hospital, Miyagi, Japan;
3Graduate School of Biomedical Engineering, Laboratory of Rehabilitative Auditory Science/Graduate School of Medicine Department of Audiology, Miyagi, Japan.

Introduction: Removal of the cholesteatoma matrix for management of labyrinthine fistula (LF) is associated with a risk of causing deafness, and the most appropriate technique has been disputed for years. Recently we have developed a technique of underwater endoscopic ear surgery (UWEES) for closure of LF while preserving auditory function by avoiding unexpected introduction of air into the labyrinth.

Methods:
– Patients: Twelve cases of LF treated with the UWEES technique at Tohoku University Hospital and Osaki City Hospital.
– Intervention: Treatment of LF with the UWEES technique. The cholesteatoma was extirpated in advance except for the island lesion of the matrix over the fistula under an operating microscope. The mastoid cavity was filled completely with perfusate delivered via an Endo-scrub lens cleaning sheath (Medtronic) covering a 0-degree 2.7-mm-diameter high-definition endoscope (Storz), as reported previously. Artificial cerebrospinal fluid (ARTCEREB, Otsuka) was used as the perfusate, except for earlier cases when saline was employed. The island residual matrix was exfoliated and the LF was closed using autologous fascia reinforced with bone chips, bone wax, or bone paste.

Discussion:
– Main Outcome Measures: All cases of LF were treated successfully by closure with UWEES.
– Results: The membranous labyrinth of the semicircular canal and the portion of the fistula were identified clearly in all cases. Despite the relatively long exposure of the canal, bone conduction thresholds were well preserved, and vertigo and dizziness were slight in most cases.

Conclusions: For LF we recommend closure with UWEES, thus preserving auditory function.