LAUSR

We thank the authors for their comments on the paper. We described a technique for approaching petrous apex cholesteatomas using combined lateral microscopic/endoscopic approaches [1], and discussed the utility of endoscopy in managing matrix inside the petrous apex. In this paper, we emphasized the advantage of obtaining good visualization of the medial surface of the internal carotid artery using endoscopy. We also believe that the transcochlear approach [2], modified transcochlear approach [3] and transotic approach [4] are essential techniques to treat petrous apex cholesteatomas. Potential advantages of an endoscopic approach to ear surgery include the possibility of obtaining a good surgical view with less invasiveness. We focused on the “good surgical view” achieved with endoscopy in our paper. The authors point out the “less invasive” advantage of using endoscopy in managing petrous apex cholesteatoma. We basically agree with the author’s opinion. When the facial canal is functional before surgery, maintaining a bony shell to protect the facial nerve is an excellent option. We believe that endoscopy could be a tool to making this possible. To further confirm the efficacy and safety of the surgical concept, we need to use this treatment concept in a large number of cases in a future study.