Partial Labyrinth Removal Restricted to the Superior Semicircular Canal in Focal Combined Transpetrosal Approach: Description and Illustrative Cases

BACKGROUND AND OBJECTIVES

The labyrinthine structures obstruct the surgical view of the deep petroclival region in the transpetrosal approach. Historically, labyrinthectomy and removal of all 3 semicircular canals, with resultant deafness, was used in patients with ipsilateral functional hearing deficits to improve access. The advent and systematization of superior and posterior semicircular canal removal (transcrusal approach) with good rates of hearing preservation has allowed a redefinition of the possibility of partial labyrinthectomy in patients without previous hearing deficits. The present manuscript is intended to describe a technical refinement of partial labyrinthectomy during focal combined petrosectomy, offering a customization of the approach through the selective removal of the superior semicircular canal for specific types of tumors.

METHODS

The use of the technique is demonstrated through surgical drawings, pictures, and videos. The rationale to indicate this new approach is discussed based on clinical cases.

RESULTS

Three illustrative clinical cases (petroclival meningiomas) are demonstrated. Functional hearing on the approach side has been preserved in all of them.

CONCLUSION

The focal combined transpetrosal approach associated with the superior semicircular canal resection has been a promising surgical technique in the treatment of selected petroclival tumors. It has the potential to further decrease the risks of postoperative auditory and vestibular dysfunctions associated with labyrinthectomies.

Hearing preservation middle fossa approach for intracanalicular vestibular schwannoma in a NF2 patient

Hearing preservation is a cornerstone in the management of intracanalicular vestibular schwannomas. This video demonstrates a middle fossa approach to an intracanalicular schwannoma and highlights some technical and anatomical nuances relevant to the procedure. The patient had sustained hearing preservation in the postoperative period. There are potential benefits in favor of the middle fossa when the tumor reaches the fundus of the internal auditory canal, but the surgeon’s individual experience plays a decisive role in the choice of approach.

The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21121

Tentorial Peeling: Surgical Extradural Navigation to Protect the Temporal Lobe in the Focused Combined Transpetrosal Approach

BACKGROUND

Transpetrosal approaches have been used for treatment of tumors in the petroclival region for many years. Injury to the temporal lobe, however, has been a potential drawback of the techniques described to date.

OBJECTIVE

To describe modifications of the transpetrosal surgical technique, which allows extradural manipulation of the temporal lobe during the focused combined transpetrosal approach. This extra layer of protection avoids mechanical brain retraction, direct trauma to the temporal lobe and disruption of the local venous structures.

METHODS

The present manuscript describes an innovative technical nuance based on the combination of the focused combined transpetrosal approach, the peeling of the dural layers of the tentorium, and the reverse peeling of the middle fossa dura mater. Ample illustrative material is provided and illustrative cases are presented.

CONCLUSION

Peeling of the dural layers of the tentorium is a promising modification of the transpetrosal approach to increase the safety of the temporal lobe manipulation.