Cochlear Implants in Inner Ear Malformations-Considerations Regarding the Role of Imaging in Preoperative Evaluation

Background/Objectives: Addressing cochlear malformations in the context of cochlear implantation is particularly important because the dimensions of the cochlea can affect intraoperative surgical decisions and options as well as the postoperative outcomes of each patient. High-resolution computed tomography (CT) is routinely used to assess the dimensions of the cochlea and the presence of any structural malformations. The purpose of this paper is to evaluate the dimensions of the cochlea and its malformations by using imaging measurements and correlating the data obtained with certain types of medical devices used. Methods: A retrospective observational study was conducted, through the systematic analysis of computed tomography images, on 130 cochlear implants between 2014 and 2024 at the ENT Clinic in Târgu Mureș, Romania, analyzing 103 patients. Data related to the anatomical features of the cochlea and their dimensions were evaluated, with an emphasis on the volume of the malformed and non-malformed cochleas. The collected data were statistically analyzed, evaluating the volume of the cochlea in relation to the gender and age of the patients, as well as the presence of cochlear malformations related to the analyzed side-the right and left ear. Results: The age groups analyzed were 58% between 0 and 7 years, 14% between 8 and 17 years, and 28% between 17 and 68 years, with the minimum age for implantation being 10 months and the maximum age being 68 years. Analyzing the presence of malformations by gender, it was found that enlarged cochlear aperture occurs at a rate of 14.89% in females and 17.02% in males, while an enlarged vestibular aqueduct occurs at a rate of 4.26% in females and 8.51% in males. Incomplete partition types I and II have a frequency of 10.64% in women and 14.89% in men. Incomplete partition type I is equally present in 10.64% of women and men. Cochlear hypoplasia occurs at a low frequency of 2.13% in women and is not observed in men in our analysis. Conclusions: In this study, we analyzed cochlear volume variables between malformed and normal cochleae. Cochlear dimensions (width and height) did not show statistically significant variations between the right and left ears, both in malformed and non-malformed cochleae. The cochlear volume is consistent across the groups studied and is not influenced by malformations or the demographic variables analyzed. Cochlear malformations, according to our assessments, do not present contraindications for a cochlear implant, which nevertheless demonstrates that a preliminary imaging assessment is extremely useful for determining the type of implant that can be used.