[Application of intraoperative CT-assisted positioning in difficult cases of cochlear implantation].

Objective:To report the experience of using CT-guided cochlear implant surgery in difficult cases such as severe inner ear deformities and anatomical abnormalities, and to discuss the application value of intraoperative CT-assisted localization in difficult cases of cochlear implant surgery. Methods:Retrospectively analyzed the clinical data of 23 cases of difficult cochlear implant surgery cases completed by our team with the assistance of intraoperative CT, and collected their medical data, including preoperative imaging manifestations, surgical conditions, and intraoperative imaging images for evaluation. Results:During the study period, 23 difficult cases（27 ears） underwent cochlear implantation under the guidance of intraoperative CT, and 4 cases were bilaterally implanted. Including 6 cases of incomplete segmentation type Ⅰ（IP-Ⅰ）, 1 case of incomplete segmentation type Ⅱ（IP-Ⅱ）, 10 cases of incomplete segmentation type Ⅲ（IP-Ⅲ）, 3 cases of common cavity deformity（CC） and 3 cases of cochlear ossification after meningitis. Facial nerve anatomy was abnormal in 9 cases, cerebrospinal fluid "blowout" was serious in 14 cases, electrode position was abnormal in 3 cases requiring intraoperative adjustment of electrode position, anatomical difficulties required intraoperative CT to assist in finding anatomical landmarks in 2 cases, and electrodes were not fully implanted in 3 cases. Conclusion:When faced with difficult cases with challenging and complex temporal bone anatomy, intraoperative CT can accurately evaluate the electrode position and provide intraoperative anatomical details, allowing immediate adjustment of the electrode position if necessary, providing safety guarantee for difficult cases of cochlear implant surgery and ensure accurate implantation of electrodes.