Surgeon Oriented Preoperative Radiologic Evaluation in Cochlear Implantation - Our experience with a Proposed Checklist
02 August 2017
09 March 2018
09 May 2018 (eFirst)
Introduction Preoperative temporal bone imaging studies have been routinely performed prior to cochlear implantation. Radiologists need to report these examinations with special focus on the surgeon's expectations.
Objectives To provide a basic structured format, in the form of a checklist, for reporting preoperative computed tomography (CT) and to its clinical impact on operative findings.
Methods The preoperative temporal bone CT scans of 47 patients were analyzed and reported according to the proposed checklist. Intraoperative assessment of mastoidectomy, posterior tympanotomy and round window access was done by the surgeon in a blinded fashion and were correlated with the radiological findings to assess its significance.
Results The proposed radiological checklist was reliable in assessing operative difficulty during cochlear implantation. Contracted mastoid and lower tegmen position were associated with a greater difficulty of the cortical mastoidectomy. Presence of an air cell around the facial nerve (FN) was predictive of easier facial recess access exposure. Facial nerve location and posterior external auditory canal (EAC) wall inclination were predictive of difficult round window (RW) accessibility.
Conclusion Certain parameters on the preoperative temporal bone CT scan may be useful in predicting potential difficulties encountered during the key steps involved in cochlear implant surgery.
- 1 Vaid S, Vaid N. Imaging for cochlear implantation: structuring a clinically relevant report. Clin Radiol 2014; 69 (07) e9-e24
- 2 Bettman RH, Van Olphen AF, Zonneveld FW, Huizing EH. Preoperative imaging protocol for cochlear implant candidates. Acta Otolaryngol 2004; 124 (09) 1028-1032
- 3 Sun DI, Lee DH, Jang KH. , et al. A suggested new classification system for the anatomic variations of the sigmoid sinus: a preliminary study. Int Adv Otol 2009; 5: 1-5
- 4 Pereira Júnior AR, Pinheiro SD, Vieira de Castro JD. , et al. Mastoidectomy: anatomical parameters x surgical difficulty. Int Arch Otorhinolaryngol 2012; 16 (01) 57-61
- 5 Mandour MF, Khalifa MA, Khalifa HA, Tomoum MO. A novel radiologic check test of round window accessibility for cochlear implantation: Our experience in 198 cases. Clin Otolaryngol 2017; 42 (05) 1108-1111
- 6 Park E, Amoodi H, Kuthubutheen J, Chen JM, Nedzelski JM, Lin VY. Predictors of round window accessibility for adult cochlear implantation based on pre-operative CT scan: a prospective observational study. J Otolaryngol Head Neck Surg 2015; 44: 20
- 7 Cooper HR. Selection criteria and prediction of outcomes. In: Huw R, Cooper LCC. , editor. Cochlear Implants: A Practical Guide. Second Edition ed. London and Philadelphia: Whurr Publishers; 2006: 132-150
- 8 Lee DH, Kim JK, Seo JH, Lee BJ. Anatomic limitations of posterior tympanotomy: what is the major radiologic determinant for the view field through posterior tympanotomy?. J Craniofac Surg 2012; 23 (03) 817-820
- 9 Kashio A, Sakamoto T, Karino S, Kakigi A, Iwasaki S, Yamasoba T. Predicting round window niche visibility via the facial recess using high-resolution computed tomography. Otol Neurotol 2015; 36 (01) e18-e23