Postauricular, transpetrous, presigmoid approach for extensive skull base tumors in the petroclival region: the successes and the travails.

PURPOSE: Postauricular, transpetrous, presigmoid approach combines a supra/infratentorial exposure with partial petrosectomy to access third to the twelfth cranial nerves and extraaxial lesions situated anterolateral to brainstem. It provides a shorter working distance to large petrosal, petroclival, cerebellopontine, and cerebellomedullary cisternal lesions and their extensions to the subtemporal-infratemporal areas. This study reviews the surgical technique, corridors of extension, and complications encountered utilizing this approach for excising extensive lesions in these locations.

METHODS

The lesions (n = 14) included petroclival meningiomas [(n = 5), including three recurrent lesions], dumbbell lower cranial nerve schwannomas (n = 2), giant acoustic schwannomas (n = 2), recurrent giant trigeminal nerve schwannoma (n = 1), glomus jugulare (n = 3), and recurrent petrous aneurysmal bone cyst (n = 1). The approach was combined with a retrosigmoid suboccipital craniectomy (n = 3), with an infratemporal approach (n = 2), and with an extreme lateral transcondylar approach and a translabyrinthine approach in one patient each, respectively. External auditory canal was not ligated in nine patients, superior petrosal sinus and tentorial division was performed in all patients, and sigmoid sinus-internal jugular vein was excised in three patients (with a glomus jugulare (n = 1) and petroclival meningioma (n = 2), respectively). Repair was performed with fat-fascia, pedicled pericranium, and temporalis muscle. Lumbar drain was placed for three to five postoperative days.

RESULTS

Total excision was performed in nine patients. Small tumor remnants were left attached to the brainstem (n = 3, petroclival meningioma), carotid canal and cavernous sinus (n = 1, glomus jugulare), and sigmoid sinus-jugular bulb (n = 1, recurrent trigeminal schwannoma). A two-staged procedure was performed in three patients. Two patients with recurrent giant petroclival meningiomas died: one with lower cranial nerve paresis due to aspiration pneumonitis and the other with cerebrospinal fluid otorrhoea and secondary meningitis.

CONCLUSIONS

The approach facilitates direct tumor decompression and its retraction away from the brainstem without initially encountering the intracisternal cranial nerves and neuraxis. It provides multiple corridors for excising extensive posterior fossa tumors. Preoperative assessment of sigmoid sinus dominance, jugular bulb height, labyrinth, vein of Labbe, and space available through Trautman's triangle considerably helps in complication avoidance.