Petrous Bone Cholesteatoma: Radical Excision with an Endeavour for Hearing Preservation

To describe surgical outcomes following resection of giant petrous bone cholesteatoma. Retrospective cohort study was undertaken at a tertiary care centre on patients who had undergone surgery for petrous bone cholesteatoma (PBC) from August 2014 to September 2017. For patients with serviceable hearing preoperatively, labyrinth preserving techniques, namely, modified transmastoid translabyrinthine approach (massive PBC-1) and supralabyrinthine approach (supralabyrinthine PBC-1) were considered. In the former, bony labyrinth which had been destroyed due to the disease process, membranous labyrinth remained anatomically and functionally intact following meticulous dissection to remove cholesteatoma matrix. In the latter, supralabyrinthine cell tracts were exenterated without disturbing the cochlea and labyrinth with a canal wall down mastoidectomy. For the remaining patients, labyrinth ablative approach was undertaken (translabyrinthine/transotic). Facial nerve function was evaluated using House-Brackman grading system. Hearing was evaluated using pure tone audiometry. 7 patients were identified (massive-2, supralabyrinthine-3, supralabyrinthine apical-1, infralabyrinthine apical 1). None of the patients experienced deterioration of postoperative bone conduction or facial nerve function (preop-grade 5-4, grade 6-3; postop-grade 2-1, grade 3-2, grade 4-4). Facial nerve was decompressed and anatomically intact in 3 cases. In the remaining, facial hypoglossal anastomosis was done in 3 and facial masseteric anastomosis was done in 1 patient. With a median follow-up of 26 months, recurrence in the form of keratin pearl was seen in 1 patient. Modified translabyrinthine approach preserving membranous labyrinth is a promising hearing preservation strategy.