| Case-1
A 56 year old
female presented with pain in the neck, tinnitus and vertigo on
bending down of 18 months duration. CT showed destruction of the
petrous apex, IAM and jugular foramen caused by a large CP angle
lesion. MRI showed the same tumour superiorly involving the preganglionic
segment of the 5th cranial nerve. Inferiorly it extended to the
hypoglossal canal with the involvement of IX, X and XI nerve bundles.
It displaced the cerebellum inferiorly causing tonsillar herniation.
Laterally it extended into the IAM with involvement of VII and VIII
cranial nerves. Total excision of the mass (schwannoma) was carried
out using the transcochlear approach.
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Schematic view of the area of bone removal in transcochlear
exposure.
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MRI
shows tumour in the CP angle. |
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| Blind
closure of external auditory canal and subtotal petrosectomy
is done. Posterior labyrinthectomy in progress. Mastoid and
tympanic segments of facial nerve are decompressed.
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IAC
is deroofed. Facial nerve skeletonised from IAM to stylomastoid
foramen. Picture shows exposure of greater superficial petrosal
nerve which is divided before posterior rerouting of facial
nerve. Single black arrow -Labyrinthine segment; Double black
arrow - Geniculate ganglion; Black outline arrow -Tympanic segment.
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Facial nerve is rerouted posteriorly. Cochlea and then clivus
are drilled out.
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Postoperative
CT shows no residual tumour. |
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