Faculty Collaboration Database

Endolymphatic duct violation during retrosigmoid dissection of the internal auditory canal: a human temporal bone radiographic study. Laryngoscope 2004 Nov;114(11):1936-40

Date

10/29/2004

Pubmed ID

15510017

DOI

10.1097/01.mlg.0000147923.19852.3a

Scopus ID

2-s2.0-9144266452 (requires institutional sign-in at Scopus site)   11 Citations

Abstract

OBJECTIVE/HYPOTHESIS: Successful hearing preservation after acoustic neuroma resection is sometimes complicated by delayed hearing deterioration. The goal of this study was to investigate the hypothesis that internal auditory canal (IAC) drilling during retrosigmoid acoustic neuroma removal may result in endolymphatic duct (ELD) injury, a potential cause of delayed hearing loss (HL) after hearing preservation surgery.

STUDY DESIGN: Temporal bone anatomic and radiographic study and literature review.

METHODS: Twenty-one human temporal bones were analyzed with high-resolution multislice computed tomography (HRMCT) and subjected to standard retrosigmoid IAC dissection with labyrinthine preservation and follow-up HRMCT for analyses of the ELD. A MEDLINE search was performed of studies documenting long-term hearing preservation outcomes after retrosigmoid dissection.

RESULTS: Five of 21 (24%) bones were found to have violation of the ELD despite preservation of labyrinthine structures and the endolymphatic sac. These results correlate with the mean incidence of long-term hearing decline (26.6%). Reviews of human and animal studies indicate that injury to the ELD may create endolymphatic hydrops.

CONCLUSIONS: The ELD is vulnerable to injury during IAC dissection even if labyrinthine structures at the lateral aspect of the IAC are preserved. These findings may be helpful in explaining and potentially preventing some cases of long-term hearing deterioration that may be a result of endolymphatic hydrops after ELD injury during acoustic tumor removal. Careful preoperative review of imaging studies using HRMCT may prove useful before retrosigmoid dissection.

Author List

Sulman CG, Vecchiotti MA, Semaan MT, Lewin JS, Megerian CA

Author

Cecille Sulman MD Chief, Professor in the Otolaryngology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Cadaver
Ear, Inner
Endolymphatic Duct
Humans
Intraoperative Complications
Neuroma, Acoustic
Temporal Bone
Tomography, X-Ray Computed