Partial Labyrinthectomy and Closure with Underwater Endoscopic Ear Surgery for Approaching the Petrous Apex

By June 7, 2019

Yamauchi, Daisuke1; Honkura, Yohei1; Kawamura, Yoshinobu1,2; Hara, Yosuke1; Ikeda, Ryoukichi2; Miyazaki, Hiromitsu2; Kobayashi, Toshimitsu2; Kawase, Tetsuaki3;Katori, Yukio1
1 Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Miyagi, Japan;
2 Sen-En Rifu Otological Surgery Center, Miyagi, Japan;
3 Graduate School of Biomedical Engineering, Laboratory of Rehabilitative Auditory Science/Graduate School of Medicine Department of Audiology, Miyagi, Japan.

It is difficult to preserve auditory function when the trans-labyrinth approach is chosen for reaching lesions in the petrous apex, since unexpected introduction of air into the cochlea usually results in deafness. Recently we have succeeded in developing an underwater endoscopic ear surgery (UWEES) technique for treatment of labyrinthine fistula and superior semicircular canal dehiscence with preservation of auditory function. Here we performed partial labyrinthectomy using UWEES for petrous apex cholesteatomas.

– Patients: 
Five cases of petrous apex cholesteatoma treated at Tohoku University Hospital and Sen-En Rifu Otological Surgery Center between 2015 and 2018.
– Intervention: Partial labyrinthectomy and closure using UWEES for approaching the petrous apex. 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 perfusate except in one case using saline. Closure was accomplished by plugging with autologous fascia reinforced by bone wax, bone paste or artificial bone paste (BIOPEX, HOYA Technosurgical).

– Main Outcome Measures: 
All cases of petrous apex cholesteatoma were removed successfully followed by partial labyrinthectomy and closure of the vestibule using UWEES.
– Results: Despite relatively long exposure of the labyrinth, bony conductance thresholds were preserved in the acute phase, but increased after a while in the worst case. Vertigo and dizziness were slight in all cases.

Partial labyrinthectomy and closure using UWEES is a useful technique for preservation of auditory function and approaching petrous apex lesions.