• easier than middle fossa approach
• risk of facial nerve weakness compared to middle fossa was reduced from 4% to 0%

• more incomplete denervation of the vestibular labyrinth than rerosigmoid
• fat graft from abdomen is used to prevent cerebrospinal fluid (CSF) leak
• 10% incidence of CSF leak (increased risk)
• limited exposure of neurovascular stuctures in cerebellopontine angle (CA)
• lack of a cleavage plane at the porus acousticus

Pros

Cons

• ability to completely section all vestibular fibers before they become closer to the cochlear fibers
• stray fibers have little chance to cross over and travel along the facial and cochlear nerves

• greater risk of facial nerve injury, sensorincural hearing loss, and neurological complications (aphasia, seizures & hemiparesis)
• hard to locate the internal canal
• limited exposure within the canal due to position of facial nerve
• hard to cut vestibular nerve without putting pressure on cochlear and facial nerves because the vestibular nerve lies deep within the canal
• only used 8% of the time

• easier than middle fossa approach
• better and more complete denervation of the vestibular labyrinth than retrolabyrinthine
• minimal retraction on cerebellum results in wide exposure of CA
• fat graft is unneccessary because dure can be closed easier
• has slightly less recurrent postoperative vertigo than retrolabyrinthine
• better visualization of the neurovascular structures than retrolabyrinthine

• failure of this approach may come from the fact that the vestibular fibers are crossed with the facial and cochlear nerves
• severe headaches more common due to greater release of occipital musculature - 25% of patients require medication 2 years later