Importance of preoperative HRCT temporal bone in the orientation of the cochlea and its relation to intra-operative difficulties in cochlear implantation – predicting the grades of difficulty

Abstract

Objective:

This study emphasizes the role of preoperative high-resolution computed tomography (HRCT) temporal bone in evaluating the variation in cochlear orientation and proposes a grading system to determine the level of intraoperative difficulties encountered.

Methods:

Preoperative correlation of middle ear and inner ear structures along with the basal turn angle (BTA) was done to assess the orientation. Patients were divided into three groups depending on BTA and radiology findings.

Results:

Group A (BTA = 55°-60°) had statistically significant (p < 0.05) correlation between middle ear to inner ear structures on HRCT, whereas group B (BTA >60°) and C (BTA <55°) had variations in the alignment of middle ear structures to their corresponding inner ear structures.

Conclusion:

The association of BTA to the correlation between middle ear and inner ear structures can determine the orientation of the cochlea. This evaluation makes the surgeon aware of intraoperative challenges and helps in surgical planning.

Keywords:

• Cochlear implants
• radiology
• sensorineural hearing loss
• pediatric neurotology
• round window
• posterior tympanotomy
• cochlear implant surgery
• cochlea

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.

Notes on contributors

Neeraj Suri

Dr. Neeraj Suri is an ENT surgeon and cochlear implantologist and as associate professor, ENT dept, Gandhinagar Civil Hospital, Gandhinagar, Gujarat. She was awarded the Rashtriya Gaurav award for dedicated work in the field of hearing at New Delhi in August 2023 and awarded excellence in the field of deafness for hearing-impaired children by honorable Mrs. Smriti Irani (Central Cabinet Minister) in 2022. She was facilitated by Gujarat Chief Minister for the deafness program in Gujarat in 2017. She was a pioneer in UNHS in Gujarat, India and a mentor for cochlear implant fellowship course in Cochlear implants in Gandhinagar Civil Hospital, Gandhinagar. She is the author of the books- “Speak-a-boo”- (Crossword), Hearing Tales, and “Imaging Handbook on Anatomy of Cochlea” published by Thieme in September 2023. Has published more than 40 original articles in both national and international journals of otorhinolaryngology. • Her special interests include working for the deafness control program and organ donation.

Diva Sharma

Dr. Diva Sharma is an ENT surgeon at Gandhinagar Civil Hospital, Gandhinagar, Gujarat, India. She is a Member American Cochlear Implant Alliance (ACI) and of The Association of Otolaryngologists of India (AOI) Working for deafness program - UNHS in Gujarat. She is an active member of Rehabilitation Centre for Cochlear Implant Recipients and has published more than 10 original articles in both national and international journals of otorhinolaryngology. Her special interests include working for the deafness control program, BLIND children and organ donation.