J Neurol Surg A Cent Eur Neurosurg 2021; 82(04): 369-374
DOI: 10.1055/s-0040-1709162
Surgical Technique

Cerebellopontine Angle Surgery Assisted by Continuous Mapping of the Facial Nerve Via the Ultrasonic Aspirator

Marco Cenzato
1   Department of Neurosurgery, Great Niguarda Hospital, Milano, Lombardia, Italy
Roberto Stefini
2   Department of Neurosurgery, Ospedale Civile di Legnano, Legnano, Lombardia, Italy
Francesco Zenga
3   Department of Neurosurgery, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Piemonte, Italy
Maurizio Piparo
1   Department of Neurosurgery, Great Niguarda Hospital, Milano, Lombardia, Italy
Alberto Debernardi
1   Department of Neurosurgery, Great Niguarda Hospital, Milano, Lombardia, Italy
Ilaria Costi
4   Department of Neurophysiology, Great Niguarda Hospital, Milano, Lombardia, Italy
5   Department of Neurosurgery, Great Niguarda Hospital, Università degli Studi di Milano BIOMETRA,, Milano, Lombardia, Italy
› Author Affiliations


Background Cerebellopontine angle (CPA) surgery carries the risk of lesioning the facial nerve. The goal of preserving the integrity of the facial nerve is usually pursued with intermittent electrical stimulation using a handheld probe that is alternated with the resection. We report our experience with continuous electrical stimulation delivered via the ultrasonic aspirator (UA) used for the resection of a series of vestibular schwannomas.

Methods A total of 17 patients with vestibular schwannomas, operated on between 2010 and 2018, were included in this study. A constant-current stimulator was coupled to the UA used for the resection, delivering square-wave pulses throughout the resection. The muscle responses from upper and lower face muscles triggered by the electrical stimulation were displayed continuously on multichannel neurophysiologic equipment. The careful titration of the electrical stimulation delivered through the UA while tapering the current intensity with the progression of the resection was used as the main strategy.

Results All operations were performed successfully, and facial nerve conduction was maintained in all patients except one, in whom a permanent lesion of the facial nerve followed a miscommunication to the neurosurgeon.

Conclusion The coupling of the electrical stimulation to the UA provided the neurosurgeon with an efficient and cost-effective tool and allowed a safe resection. Positive responses were obtained from the facial muscles with low current intensity (lowest intensity: 0.1 mA). The availability of a resection tool paired with a stimulator allowed the surgeon to improve the surgical workflow because fewer interruptions were necessary to stimulate the facial nerve via a handheld probe.

Publication History

Received: 21 March 2019

Accepted: 22 October 2019

Article published online:
21 October 2020

© 2020. Thieme. All rights reserved.

Georg Thieme Verlag KG
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