A Pilot Cadaveric Investigation Recommending the Lesser Petrosal Nerve as an Anatomical Landmark for Middle Fossa Approaches

If the most posterior part of the groove for LPN is traced posteriorly for approximately 5 mm, the head of the malleus is reached by opening the tegmen tympani. Taking the medial margin of the head of the malleus as reference, a surgeon may find the superior semicircular canal, by following it along 110° posterior to the long axis of LPN. In addition, the surgeon may detect the internal acoustic canal, by tracing it along 78° posterior to the long axis of LPN. Our strategy is based on the initial identification of LPN and then access to SSC and IAC by forming a surgical map through LPN.