Objectives

We aim to evaluate the utility of the Round Window Angle (RWA) as a predictor of difficulty and operative time in cochlear implantation.

Methods

A retrospective study of pediatric patients that underwent cochlear implantation and CT temporal bone imaging from January 2008 to November 2019. Correlation, univariate, and multivariate analysis were conducted.

Results

347 implantations met inclusion criteria. We found a difference in RWA for difficult (median: 101°, n = 5) and non-difficult (median: 74, n = 317) implantations (p < 0.0001). There was also a difference in RWA in patients with round windows visualized intra-operatively (p < 0.0197). When controlling for age and intraoperative round window visualization, logistic regression showed RWA was significantly associated with difficult insertion (OR: 1.687; p = 0.0246). Further, there was positive correlation between RWA and operative time (r = 0.1779, p = 0.0013) with patients with acute RWAs having shorter operative times (mean 115.7 ± 32.1 min) than those with obtuse RWA (mean 183.5 ± 97.0 min) (p = 0.0035). When accounting for surgeon and patient age, multivariate linear regression showed round window visualization (β = 3.456, p = 0.0006) and obtuse RWA (β = 6.172, p < 0.0001) was associated with an increase in operative time.

Conclusion

Further research is needed to identify difficult cochlear implantations to increase the success and reduce risks associated with the surgery. Our study reports the possibility that an obtuse RWA both significantly increases difficulty and time of operation due to decreased round window visualization.

中文翻译：

---

圆窗解剖学预测儿童人工耳蜗植入的难易程度

目标

我们旨在评估圆窗角 (RWA) 作为人工耳蜗植入难度和手术时间预测指标的效用。

方法

一项回顾性研究 2008 年 1 月至 2019 年 11 月接受人工耳蜗植入和 CT 颞骨成像的儿科患者。进行了相关性、单变量和多变量分析。

结果

347 个植入物符合纳入标准。我们发现困难（中位数：101°，n = 5）和非困难（中位数：74，n = 317）植入的 RWA 存在差异（p < 0.0001）。手术中观察到圆窗的患者的 RWA 也存在差异（p < 0.0197）。当控制年龄和术中圆窗可视化时，逻辑回归显示 RWA 与插入困难显着相关（OR：1.687；p = 0.0246）。此外，急性 RWA 患者的手术时间较短（平均 115 .7 ± 32.1 分钟）比那些具有钝角 RWA 的人（平均 183.5 ± 97.0 分钟）（p = 0.0035）。在考虑外科医生和患者年龄时，多元线性回归显示圆窗可视化（β = 3.456，p = 0.0006）和钝角 RWA（β = 6.172，p < 0.0001）与手术时间增加相关。

结论

需要进一步研究以确定困难的人工耳蜗植入，以提高成功率并降低与手术相关的风险。我们的研究报告了由于圆窗可视化降低，钝角 RWA 会显着增加操作难度和时间的可能性。