====== Transmastoid approach ======

[[Petrous bone cholesteatoma]] is a rare pathologic entity and maybe a difficult surgical challenge because of the potential involvement of the [[facial nerve]], [[carotid artery]], [[dura mater]], [[otic capsule]] and superior petrosal or [[lateral sinus]]. 

Eight patients (nine ears) who underwent endoscope-assisted petrous bone surgery for [[cholesteatoma]]. [[Pure tone audiometry]], [[magnetic resonance imaging]] were performed at preoperatively, and at approximately 12 months postoperatively.

Endoscope assisted surgery was performed in 8 patients and 9 ears. Of these patients, 6 were male and 2 were females. The median age was 19,5 (range 7-52) years. The [[hearing]] was able to preserved in 8 ears (8/9). Recurrence disease was observed one ear in long term follow up (1/9). In another one patient, cholesteatoma pearl was removed in the office.

Endoscope-assisted surgery can allow removal of cholesteatoma of [[petrous apex]] with preserving hearing. It also provides to remove the cholesteatoma via [[transmastoid approach]] for perilabyrinthine space as "minimally invasive surgery" instead of [[middle fossa approach]] that is standard surgical procedure. In apical and peri-labyrinthine cholesteatomas, endoscopes allow to preserve hearing with middle fossa approach instead of trans-otic/ trans-labyrinthine/trans-cochlear approach
((Orhan KS, Çelik M, Polat B, Aydemir L, Aydoseli A, Sencer A, Güldiken Y.
Endoscope-Assisted Surgery for Petrous Bone Cholesteatoma with Hearing
Preservation. J Int Adv Otol. 2019 Dec;15(3):391-395. doi: 10.5152/iao.2019.7212.
PubMed PMID: 31846917.
)).
----
The trans[[mastoid]] [[approach]] allows better control of the [[clivus]] and paraclival regions, however, the supratentorial part of the lesions are out of surgical view
((Bambakidis NC, Kakarla UK, Kim LJ, et al: Evolution of surgical
approaches in the treatment of petroclival meningiomas: a retrospective
review. Neurosurgery 61:202‐209; discussion 209‐211, 2007))
((Cho CW, Al‐Mefty O: Combined petrosal approach to petroclival
meningiomas. Neurosurgery 51:708‐716; discussion 716‐708, 2002))
((Tummala RP, Coscarella E, Morcos JJ: Transpetrosal approaches to the
posterior fossa. Neurosurg Focus 19:E6, 2005)).


to repair of spontaneous [[temporal bone]] [[cerebrospinal fluid leak]] is highly successful. Furthermore, patients in the series from Kim et al.,had excellent hearing results with closure of their air-bone gap to ≤12 dB, which has not been previously described
((Kim L, Wisely CE, Dodson EE. Transmastoid Approach to Spontaneous Temporal
Bone Cerebrospinal Fluid Leaks: Hearing Improvement and Success of Repair.
Otolaryngol Head Neck Surg. 2014 Jan 6. [Epub ahead of print] PubMed PMID:
24395620.)).

Facial nerve decompression via the transmastoid approach with temporal lobe retraction provides better exposure to the key areas around the [[geniculate ganglion]] without complications
((Kim MW, Ryu NG, Lim BW, Kim J. Temporal Lobe Retraction Provides Better
Surgical Exposure of the Peri-Geniculate Ganglion for Facial Nerve Decompression 
via Transmastoid Approach. Yonsei Med J. 2016 Nov;57(6):1482-7. doi:
10.3349/ymj.2016.57.6.1482. PubMed PMID: 27593878; PubMed Central PMCID:
PMC5011282.
)).

===== References =====