Letter: internal auditory canal variability: anatomic variation affects cisternal facial nerve visualization

We read with great interest the paper by Cohen et al, entitled “Internal Auditory Canal Variability: Anatomic Variation Affects Cisternal Facial Nerve Visualization,” reporting relevant data on the high anatomic variability of the internal auditory canal and its impact on surgical procedures. Interindividual anatomic variability represents a relevant point in different challenging skull base procedures, such as acoustic neuromas surgery. Whenever opening the internal auditory canal (IAC) is required, in translabyrinthic or retromastoid approaches, anatomic landmark evaluation may ensure safer procedures, eventually preserving cranial nerve function. The authors quantitatively evaluated the variability of this anatomic district, carefully highlighting the relevance of IAC position and orientation within the petrous temporal bone. Morphological valuations and measurements were conducted on preoperative magnetic resonance imaging (MRI) images, properly reporting anatomicsurgical correlations. Different radiological parameters have been standardized to systematically collect data and to perform the statistical analysis.