Copenhagen Skull Base Dissection Manual

Translabyrinthine approach

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Dissection by Michael Gleeson, MD, FRCS

The translabyrinthine approach is best suited for large vestibular schwannomas wight significant intracanalicular component. 

This approach offers significant less brain retraction and good control for the facial nerve.

A prerequisite for this approach is a no serviceable hearing.

Clinical cases

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Fig. 1 and 2  The skin incision is started behind the ear, from the root of zygoma, curved to the the asterion and ends on the mastoid tip.
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Fig. 3. Mastoidectomy boundaries – the root of the zygoma, asterion (exposes the lower part of sigmoid transverse junction), and the mastoid tip.
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Fig. 4 Cortical mastoidectomy. The antrum is exposed. Lateral semicircular canal is reveled. The Sigmoid sinus and middle fossa dura are skeletonized. The digastric ridge is seen.
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Fig. 5 and 6. The labyrinthine block is exposed. The lateral, superior and posterior semicircular canals are reveled. Close up view of the antrum with short process of incus pointing to the facial nerve
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Fig. 7.  The facial nerve is exposed. The fallopian canal is opened.
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Fig 8.  Retrolabyrinthine exposure is achieved. The jugular bulb is also revealed.
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Fig. 9a and 9b The posterior and superior semicircular canals are opened. The drill is pointing at the common crus.semicircular canals are opened. The blue line of the lateral semicircular canal is exposed.
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Fig. 10 The labyrinthectomy is started. The superior vestibular stump and labyrinthine artery are exposed in the center. A thin shell of bone of the lateral semicircular canal is preserved over the fascial nerve.
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Fig. 11 Drilling is continued to IAC exposure.
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Fig. 12a
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Fig. 12b
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Fig. 12c
Fig. 12a and 12b The IAC is skeletonized in 270 degrees.  Fig. 12c The presigmoid dura and IAC are opened.
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Fig. 13 The nerves in the IAC are reveled.
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Fig. 14 Closure of the translabyrinthine exposure is performed firs by removing the incus pugging the antrum with muscle a fat graft, followed by fibrin glue application over to whole cavity.
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Fig. 15 A fat graft is placed in the defect in order to fill the dead space.
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Fig. 16. Tight fascial closure could be achieve at the end in order to further protect for CSF leak.