a SciTechnol journal Case Report Chang, et al., J Otol Rhinol 2017, 6:1 DOI: 10.4172/2324-8785.1000303 International Publisher of Science, Technology and Medicine Journal of Otology & Rhinology All articles published in Journal of Otology & Rhinology are the property of SciTechnol, and is protected by copyright laws. Copyright © 2017, SciTechnol, All Rights Reserved. Endoscopic Transcanal Approach to Remove Extensive Petrous Cholesteatoma WaiTsz WT Chang*, Thong J and Michael CF Tong Abstract Petrous cholesteatoma is a rare clinical entity and surgical treatment is difficult because the anatomical location of the petrous bone. It poses potential surgical risk of injury to the facial nerve, labyrinth, carotid artery, dura and risk of cerebrospinal fluid leak. We report a case of a young patient with extensive petrous cholesteatoma with erosion of basal turn of the cochlea, posterior semicircular canals and dehiscence of tegmen, facial nerve, carotid canal and roof of the internal auditory canal. It was successfully treated via the endoscopic transcanal approach. This surgical approach provides an excellent anatomical advantage of reaching the tumor with minimal destruction to the vital structures. It minimises soft tissue dissection and left the normally aerated mastoid untouched. It gave excellent functional aesthetic outcome with complete disease clearance. Keywords Endoscopic ear surgery; TEES; Petrous cholesteatoma *Corresponding author: WaiTsz WT Chang, MScEPB, MRCS, Department of Otorhinolaryngology–Head and Neck Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, E-mail: waitsz@gmail.com Received: October 23, 2015 Accepted: November 22, 2016 Published: January 03, 2017 Case A 32 year-old gentleman had been under follow-up in our department for extensive petrous cholesteatoma since the age of 17. He initially presented with a history of leſt otalgia and hearing loss at the age of 17. He originally consulted general practice and medical for leſt sided headache and otalgia. His physical examination was normal. Later on he developed subacute deteriation of leſt hearing and occasional dizziness. His otoscopic examination was normal but his pure tone audiogram showed leſt mixed hearing loss. e Computed tomography (CT) of the temporal bone was performed and this showed a massive labyrinthine-apical petrous cholesteatoma abutting against the carotid canal with erosion of the cochlear and abutting against the internal carotid artery. Excision Removal of the lesion via a translabyrinthine-transcochlear approach was suggested but the patient refused the procedure due to operative risk. roughout 15 years of follow-up, the patient declined surgery at each follow-up visit. He was thus closely monitored over the next 15 years during which he developed increasing symptoms of vertigo and progressive hearing loss. e follow-up CT (Figure 1) and a diffusion weighted MRI (Figure 2) scans showed a progressive disease with extensive bony erosion, including the Internal carotid artery, tegmen, facial nerve, fallopian canal, cochlear and anterior semicircular canal with labyrinthine fistula. e pure tone audiogram showed leſt severe hearing loss. His preoperative facial nerve was normal. A method involving an infracochlear approach and endoscopic transcanal excision of the petrous cholesteatoma via combined supragenieculate was adopted. (3-mm Karl Storz Hopkins II® ear endoscopes with (0°, 30° and, 45° endoscopes) lenses and Stylus high-speed drill system were used.) e Medtronic high speed drill system was used to drill off the scutum and overhangings. e ossicles were removed to improve exposure and gain access to the cholesteatoma. e cholesteatoma in the middle ear was traced and discovered to lead to the petrous bone via the suprageniculate and infracochlear routes with exposure of: anteriorly, the Eustachian tube opening; inferiorly, the jugular bulb; posteriorly, the horizontal portion of the facial nerve; and superiorly, the tegmen. e lateral semicircular canal was identified (Figure 3). Cholesteatoma above the tympanic portion of facial nerve was removed and traced to the petrous via the suprageneculate route. A small amount of cholesteatoma at the hypotympanum was removed and the main bulk was followed anterior to the cochlear. e opening was enlarged anterioinferiorly to the internal carotid artery. Complete removal of cholesteatoma was achieved and confirmed with 2.7mm 45 degree endoscope. At completion of surgery, the margins of dissection1 were the Eustachian tube opening and the internal carotid artery anteriorly, the jugular bulb inferiorly and the tegmen superiorly (Figure 3). e eroded cochlea, the horizontal portion of facial nerve and the lateral semicircular canal were all clearly visualized. Postoperatively, the patient recovered uneventfully. Postoperative facial nerve function was normal and the patient did not experience vertigo. e Pure tone audiogram showed profound hearing loss in the operated ear. e diffusion-weighted MRI is done in one year aſter the operation, which showed no recurrence or residual cholesteatoma. A schematic diagram of the anatomy during dissection is shown in Figure 4. Figure 1: CT scan showing extensive bony erosion.