Endoscopic lateral skull base surgery could be performed via less invasive techniques due to wide panoramic visualisation of the operative field. With less invasive techniques, patients have been shown to require shorter recovery time and reduced postoperative pain. In this paper, the authors describe three transcanal approaches to access the lateral skull base. The three approaches described are based on the otic capsule with transpromontorial approach, involving access through the otic capsule, whilst suprageniculate and infracochlear approaches spares the otic capsule by passing superior and inferior to the otic capsule respectively. The suprageniculate approach allows management of superior petrous apex pathologies, tumours involving the suprageniculate fossa and decompression of the facial nerve around the geniculate ganglion and distal labyrinthine segment of the facial nerve. The disadvantage of this approach is that it involves removal of the incus and head of the malleus necessitating an ossiculoplasty at the end of the operation. The infracochlear approach spares the otic capsule and the ossicular chain. This approach involves creating a corridor between the cochlea, internal carotid artery and the jugular bulb to manage inferior petrous apex pathologies including cholesterol granuloma and cholesteatoma. This approach is limited by the anatomical position of the jugular bulb and space between the jugular bulb and the carotid artery. Finally, the transpromontorial approach involves access through the cochlea to expose the internal acoustic meatus (IAC) and cerebellopontine angle (CPA). This approach can be exclusively endoscopic transcanal or could be extended to utilise the microscope as well. The transpromontorial approach is used to manage IAC pathologies such as small vestibular schwannomas (Koos grade I or II). In conclusion, this is an interesting article discussing minimally invasive endoscopic approaches to the lateral skull base. Perhaps image-guided navigation could also be utilised as an adjunct when performing minimally invasive approaches.
Lateral skull base surgery using the endoscope
Reviewed by Sam Cho
Endoscopic assisted lateral skull base surgery.
