Extended Retrosigmoid Craniotomy

Lesions in the cerebellopontine angle and petroclival region can be surgically challenging to resect because of surrounding vascular and eloquent neural structures (i.e., brainstem) that have zero tolerance for retraction. Numerous surgical approaches, such as translabyrinthine, transcochlear, and presigmoid approaches, are part of the surgeon’s armamentarium. Retrosigmoid craniotomy allows for easy and rapid access to the cerebellopontine angle.

The extended version of the traditional retrosigmoid craniotomy increases the angle of view by about 50% and decreases the operative working distance. It is characterized by bony skeletonization of the sigmoid and transverse sinuses with an optional additional mastoidectomy. This modified version permits access to areas that are difficult to access with the classic approach—ventral to the brainstem and near the tentorium— and also limits the amount of cerebellar retraction required. This technique can often serve as a safe alternative to more radical cranial base approaches.

This approach can be employed for extraaxial lesions in the cerebellopontine angle and intraaxial lesions arising along the petrosal surface of the cerebellum, cerebellar peduncles, or brainstem.

Patients must have patent contralateral transverse and sigmoid sinuses before manipulation of the sinuses ipsilateral to the approach.

This approach is relatively contraindicated in older patients with poor quality dura mater; in these patients, a craniectomy as opposed to a craniotomy would be preferred.