摘要
Objective:This study was conducted to determine whether there is a reliable method for measuring the thickness of the retroauricular skin before,during,and after cochlear implantation,which allows the assessment of the optimal force of the external magnet of the cochlear implant(CI).Methods:The retroauricular skin thickness of 83 patients who received a CI was measured using three different methods.The thickness was measured on pre-and postoperative CT images,as well as intraoperatively.The magnet category chosen by the surgeon was recorded when the implant was switched on and during the first follow-up visit.Correlation analyses were performed on the different skin thickness measurements and between the skin thickness and magnet strength categories.Results:Only six patients required an exchange of the magnet until the follow-up.Although the median absolute thickness differed significantly between the three measures(p<0.0001),their thickness values showed highly significant correlations(Pearson’s r=0.457-0.585;p<0.01).In addition,magnet strength,was significantly correlated with the flap thickness determined pre-,post-,and during surgery.The lowest correlation with magnet strength was found in the intraoperative needle method.Conclusion:All three measurements methods provided a suitable base for determining the ideal magnetic force.However,of particular interest were the pre-and postoperative CT measurements.The first enabled the early assessment of the required magnetic strength and thus a timely postoperative supply,whereas the latter helped to estimate the need for magnetic strength reduction during follow-up care and the feasibility of an early swith-on.
