A Rapid and Safe Middle Fossa Approach to the Geniculate Ganglion and Labyrinthine Segment of the Facial Nerve

The middle fossa approach provides neurotologic surgical access to lesions of the geniculate ganglion and the labyrinthine portion of the facial nerve as well as to the internal acoustic canal, and therefore helps preserve cochlear function. Although this approach is widely used, surgeons are still not certain which anatomic landmarks are best to locate the facial nerve and internal acoustic canal without causing labyrinthine damage. The purpose of this article is to describe a fast and safe technique to expose the geniculate ganglion and the labyrinthine portion of the facial nerve in two structures of the middle ear: the cochleariform process and the tympanic portion of the facial nerve. We prospectively evaluated 32 patients who underwent surgical facial nerve exploration via the middle fossa approach. Our goal was to determine the incidence of intraoperative difficulties and complications; we found none, and hearing levels could not be maintained in only one of the 32 patients. Our technique allowed us to decompress the first genu and the labyrinthine segment of the nerve. It also allowed us to reach and manipulate its tympanic segment in a very short amount of surgical time.

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Resection of a Dumbbell-Shaped Facial Nerve Schwannoma With Preservation of Facial Nerve Function Through the Extended Middle Fossa Approach: 2-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opab335 ◽

2021 ◽

Author(s):

Kaith K Almefty ◽

Wenya Linda Bi ◽

Walid Ibn Essayed ◽

Ossama Al-Mefty

Keyword(s):

Facial Nerve ◽

Cerebellopontine Angle ◽

Internal Auditory Canal ◽

Growth Patterns ◽

Geniculate Ganglion ◽

Nerve Function ◽

Middle Fossa ◽

Facial Nerve Function ◽

Large Tumor ◽

Middle Fossa Approach

Abstract Facial nerve schwannomas are rare and can arise from any segment along the course of the facial nerve.1 Their location and growth patterns present as distinct groups that warrant specific surgical management and approaches.2 The management challenge arises when the facial nerve maintains good function (House-Brackmann grade I-II).3 Hence, a prime goal of management is to maintain good facial animation. In large tumors, however, resection with facial nerve function preservation should be sought and is achievable.4,5 While tumors originating from the geniculate ganglion grow extradural on the floor of the middle fossa, they may extend via an isthmus through the internal auditory canal to the cerebellopontine angle forming a dumbbell-shaped tumor. Despite the large size, they may present with good facial nerve function. These tumors may be resected through an extended middle fossa approach with preservation of facial and vestibulocochlear nerve function. The patient is a 62-yr-old man who presented with mixed sensorineural and conductive hearing loss and normal facial nerve function. Magnetic resonance imaging (MRI) revealed a large tumor involving the middle fossa, internal auditory meatus, and cerebellopontine angle. The tumor was resected through an extended middle fossa approach with a zygomatic osteotomy and anterior petrosectomy.6 A small residual was left at the geniculate ganglion to preserve facial function. The patient did well with hearing preservation and intact facial nerve function. He consented to the procedure and publication of images. Image at 1:30 © Ossama Al-Mefty, used with permission. Images at 2:03 reprinted from Kadri and Al-Mefty,6 with permission from JNSPG.

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The Bonebridge active bone conduction system: a fast and safe technique for a middle fossa approach

The Journal of Laryngology & Otology ◽

10.1017/s0022215119000501 ◽

2019 ◽

Vol 133 (4) ◽

pp. 344-347 ◽

Cited By ~ 6

Author(s):

C Carnevale ◽

M Tomás-Barberán ◽

G Til-Pérez ◽

P Sarría-Echegaray

Keyword(s):

Complication Rate ◽

Bone Conduction ◽

Conduction System ◽

Middle Fossa ◽

Surgical Time ◽

Anatomical Variant ◽

Middle Fossa Approach ◽

System A ◽

Safe Technique

AbstractBackgroundThe transmastoid pre-sigmoid approach is always the preferred choice for implantation of the Bonebridge active bone conduction system in patients with a normal anatomy. When an anatomical variant exists or a previous surgery has been performed, a retrosigmoid approach or middle fossa approach can be performed.MethodsThe preferred surgical technique for a middle fossa approach is described. A 14 mm drill head (Neuro Drill) was used to create the bed at the squamous portion of the temporal bone. Surgical time and complication rate were analysed.ResultsThe surgical time was shorter than 30 minutes in all cases, and only 14 seconds were needed to create a 14 mm bone bed. No complications were observed during the follow-up period (6–45 months).ConclusionUse of the Neuro Drill for the middle fossa approach is an easy technique. It significantly decreases the surgical time, without increasing the complication rate.

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Expansile Traumatic Neuroma of the Intratemporal Facial Nerve

Journal of Neurological Surgery Reports ◽

10.1055/s-0039-1685212 ◽

2019 ◽

Vol 80 (01) ◽

pp. e10-e13

Author(s):

Yening Feng ◽

Neil Patel ◽

Anthony Burrows ◽

John Lane ◽

Aditya Raghunathan ◽

...

Keyword(s):

Facial Nerve ◽

Cellular Proliferation ◽

Relevant Literature ◽

Geniculate Ganglion ◽

Nerve Lesion ◽

Middle Fossa ◽

Traumatic Neuroma ◽

Middle Fossa Approach ◽

Great Auricular Nerve ◽

Facial Function

Objectives To present a rare case of traumatic facial neuroma involving the geniculate ganglion and review relevant literature. Patient Thirty-year-old man. Intervention Microsurgical resection via combined mastoid-middle fossa approach with great auricular nerve interpositional graft. Main Outcome Measures Patient demographics and pre- and postoperative facial nerve function. Results A 30-year-old man with a reported history of prior Bell's palsy developed progressive complete (House–Brackmann VI) right facial paralysis following blunt trauma. Imaging was strongly suggestive of a geniculate ganglion hemangioma. As the patient had no spontaneous improvement in his poor facial function over the course of 9 months, he underwent resection of the facial nerve lesion with great auricular nerve graft interposition via a combined mastoid-middle fossa approach. Histopathology demonstrated disorganized fascicles, with axonal clustering reminiscent of sprouting/regeneration following trauma. No cellular proliferation or vascular malformation was present. Conclusion Traumatic facial nerve neuromas can occur following temporal bone trauma and can closely mimic primary facial nerve tumors. Akin to the management of geniculate ganglion hemangioma and schwannoma, preoperative facial function largely dictates if and when surgery should be pursued.

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Schwannoma of the greater superficial petrosal nerve

Otolaryngology ◽

10.1016/s0194-5998(00)70260-9 ◽

2000 ◽

Vol 122 (2) ◽

pp. 302-303 ◽

Cited By ~ 9

Author(s):

Eugene N. Myers ◽

Olaf Michel ◽

Mathias Wagner ◽

Orlando Guntinas-Lichius

Keyword(s):

Facial Nerve ◽

Geniculate Ganglion ◽

Nerve Function ◽

Middle Fossa ◽

Facial Nerve Function ◽

Progressive Hearing Loss ◽

Middle Fossa Approach ◽

Greater Superficial Petrosal Nerve ◽

Intracranial Schwannoma ◽

Ct And Mri

A case of an intracranial schwannoma originating from the greater superficial petrosal nerve with wide extension into the pterygopalatine fossa in a 20-year-old woman without neurofibromatosis is reported. The motor facial nerve including the geniculate ganglion was not affected. At presentation the patient had vertigo, progressive hearing loss, and mild facial nerve synkinesis without lacrimation deficit. The tumor was detected by CT and MRI. The tumor was completely removed with an intracranial, extradural middle fossa approach with complete preservation of the motor facial nerve function. To our knowledge, this is the first reported case of an isolated schwannoma of the greater superficial petrosal nerve without involvement of the motor facial nerve.

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Transmastoid Decompression of the Facial Nerve in Temporal Bone Fracture

Otolaryngology ◽

10.1177/019459988209000521 ◽

1982 ◽

Vol 90 (5) ◽

pp. 616-621 ◽

Cited By ~ 20

Author(s):

Naoaki Yanagihara

Keyword(s):

Facial Nerve ◽

Temporal Bone ◽

Bone Fracture ◽

Facial Palsy ◽

Bone Fractures ◽

Closed Head Injury ◽

Geniculate Ganglion ◽

Middle Fossa ◽

Temporal Bone Fracture ◽

Middle Fossa Approach

Among 41 cases of facial palsy caused by closed head injury, temporal bone fractures were surgically confirmed in 36 cases, of which there were two mixed fractures and 34 longitudinal fractures. The fracture involved the geniculate ganglion area in 20 cases (55%). In 15 cases, decompression of the facial nerve was carried out using the transmastoid supralabyrinthine approach with disarticulation of the incus; in only five cases was the middle fossa approach used. The technique avoids the craniotomy for the middle fossa approach and is a reliable method of treatment in the majority of patients with facial palsy caused by temporal bone fracture involving the geniculate ganglion area.

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Cadaveric Study to Find a Novel Method of Identifying the Internal Acoustic Canal in the Middle Fossa Approach: The Rule of 2s

Skull Base ◽

10.1055/s-2009-1242371 ◽

2009 ◽

Vol 19 (03) ◽

Author(s):

Raghuram Sampath ◽

Chad Glenn ◽

Shashikant Patil ◽

Prasad Vannemreddy ◽

Anil Nanda ◽

...

Keyword(s):

Cadaveric Study ◽

Middle Fossa ◽

Middle Fossa Approach ◽

Novel Method ◽

Internal Acoustic Canal

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Extended middle fossa approach to lateralized pontine cavernomas in children

Journal of Neurosurgery Pediatrics ◽

10.3171/2017.10.peds17381 ◽

2018 ◽

Vol 21 (4) ◽

pp. 384-388 ◽

Cited By ~ 4

Author(s):

Robert C. Rennert ◽

Reid Hoshide ◽

Mark Calayag ◽

Joanna Kemp ◽

David D. Gonda ◽

...

Keyword(s):

Trigeminal Nerve ◽

Internal Auditory Canal ◽

Csf Leak ◽

Geniculate Ganglion ◽

Gasserian Ganglion ◽

Middle Fossa ◽

Cavernous Malformations ◽

Middle Fossa Approach ◽

Cerebellar Artery ◽

Mandibular Branch

OBJECTIVETreatment of hemorrhagic cavernous malformations within the lateral pontine region demands meticulous surgical planning and execution to maximize resection while minimizing morbidity. The authors report a single institution’s experience using the extended middle fossa rhomboid approach for the safe resection of hemorrhagic cavernomas involving the lateral pons.METHODSA retrospective chart review was performed to identify and review the surgical outcomes of patients who underwent an extended middle fossa rhomboid approach for the resection of hemorrhagic cavernomas involving the lateral pons during a 10-year period at Rady Children’s Hospital of San Diego. Surgical landmarks for this extradural approach were based on the Fukushima dual-fan model, which defines the rhomboid based on the following anatomical structures: 1) the junction of the greater superficial petrosal nerve (GSPN) and mandibular branch of the trigeminal nerve; 2) the lateral edge of the porus trigeminus; 3) the intersection of the petrous ridge and arcuate eminence; and 4) the intersection of the GSPN, geniculate ganglion, and arcuate eminence. The boundaries of maximal bony removal for this approach are the clivus inferiorly below the inferior petrosal sinus; unroofing of the internal auditory canal posteriorly; skeletonizing the geniculate ganglion, GSPN, and internal carotid artery laterally; and drilling under the Gasserian ganglion anteriorly. This extradural petrosectomy allowed for an approach to all lesions from an area posterolateral to the basilar artery near its junction with cranial nerve (CN) VI, superior to the anterior inferior cerebellar artery and lateral to the origin of CN V. Retraction of the mandibular branch of the trigeminal nerve during this approach allowed avoidance of the region involving CN IV and the superior cerebellar artery.RESULTSEight pediatric patients (4 girls and 4 boys, mean age of 13.2 ± 4.6 years) with hemorrhagic cavernomas involving the lateral pons and extension to the pial surface were treated using the surgical approach described above. Seven cavernomas were completely resected. In the eighth patient, a second peripheral lesion was not resected with the primary lesion. One patient had a transient CN VI palsy, and 2 patients had transient trigeminal hypesthesia/dysesthesia. One patient experienced a CSF leak that was successfully treated by oversewing the wound.CONCLUSIONSThe extended middle fossa approach can be used for resection of lateral pontine hemorrhagic cavernomas with minimal morbidity in the pediatric population.

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Hearing Preservation Using the Middle Fossa Approach for the Treatment of Vestibular Schwannoma

Neurosurgery ◽

10.1227/neu.0b013e31823110f1 ◽

2011 ◽

Vol 70 (2) ◽

pp. 334-341 ◽

Cited By ~ 26

Author(s):

Joe Walter Kutz ◽

Tyler Scoresby ◽

Brandon Isaacson ◽

Bruce E. Mickey ◽

Christopher J. Madden ◽

...

Keyword(s):

Facial Nerve ◽

Vestibular Schwannoma ◽

Academic Medical Center ◽

Hearing Preservation ◽

Middle Fossa ◽

Middle Fossa Approach ◽

Class A ◽

Facial Function ◽

Grade Iii

Abstract BACKGROUND: The incidence of small vestibular schwannomas in patients with serviceable hearing is increasing because of the widespread use of MRI. The middle fossa approach provides the patient with an opportunity for tumor removal with hearing preservation. OBJECTIVE: To determine the rate of hearing preservation and facial nerve outcomes after removal of a vestibular schwannoma with the use of the middle fossa approach. METHODS: A retrospective case review at a tertiary, academic medical center was performed identifying patients from 1998 through 2008 that underwent removal of a vestibular schwannoma by the middle fossa approach. Preoperative and postoperative audiograms were compared to determine hearing preservation rates. In addition, facial nerve outcomes at last follow-up were recorded. RESULTS: Forty-six patients underwent a middle fossa craniotomy for the removal of a vestibular schwannoma. Of the 38 patients that had class A or class B hearing preoperatively, 24 (63.2%) retained class A or B hearing and 29 (76.3%) retained class A, B, or C hearing. When tumors were 10 mm or less in patients with class A or B preoperative hearing, 22 of 30 patients (73.3%) retained class A or B hearing. When the tumor size was greater than 10 mm in patients with class A or B preoperative hearing, 2 of 8 patients (25%) retained class A or B hearing. At most recent follow-up, 76.1% of patients had House-Brackmann grade I facial function, 13.0% had House-Brackmann grade II facial function, and 10.9% had House-Brackmann grade III facial function. CONCLUSION: Hearing preservation rates are excellent using the middle fossa approach, especially for smaller tumors. No patient experienced long-term facial nerve function worse than House-Brackmann grade III.

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Middle Fossa Approach for Facial Nerve Schwannoma Aiming for Functional Improvement: 2-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opz178 ◽

2019 ◽

Vol 18 (5) ◽

pp. E167-E168

Author(s):

Ken Matsushima ◽

Michihiro Kohno ◽

Hitoshi Izawa ◽

Yujiro Tanaka

Keyword(s):

Facial Nerve ◽

Facial Palsy ◽

Tumor Resection ◽

Nerve Fibers ◽

Middle Fossa ◽

Tumor Removal ◽

Middle Fossa Approach ◽

Brainstem Response ◽

Facial Nerve Schwannoma

Abstract The treatment paradigm of skull base surgery has been changed from radical tumor resection to maximal tumor removal while giving priority to functional preservation. Facial nerve schwannoma is one of the representative disorders of this type of paradigm shift.1 This video demonstrates facial nerve schwannoma surgery through the middle fossa approach, aiming for improvement of facial function. A 33-yr-old woman presented with gradually worsening facial palsy (House-Brackmann grade IV), dizziness, and nausea. Neuroimaging revealed a growing tumor involving the geniculate ganglion, and extending to the middle fossa, internal acoustic meatus, and cerebellopontine angle. The nerve-sparing surgery through the left middle fossa approach was performed under detailed neuromonitoring including the evoked facial electromyograms and auditory brainstem response. The facial nerve fibers were involved within the tumor mass and the plane between the tumor and facial nerve could not be identified as seen in most cases of such large facial nerve schwannomas. But sufficient tumor removal with facial nerve preservation was achieved owing to continuous facial monitoring.2 The patient had no new neurological deficits. Her facial palsy has been gradually improving, now at grade III, without any signs of tumor regrowth during the 10 mo of follow up after the operation. Careful follow up is being continued to survey the possible tumor recurrence. The video was reproduced after informed consent of the patient.

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Preservation of Facial, Cochlear, and other Nerve Functions in Acoustic Neuroma Treatment

Otolaryngology ◽

10.1177/019459989411000202 ◽

1994 ◽

Vol 110 (2) ◽

pp. 146-155 ◽

Cited By ~ 82

Author(s):

Jean-Marc Sterkers ◽

Gavin A. J. Morrison ◽

Olivier Sterkers ◽

Mohamed M. K. Badr El-Dine

Keyword(s):

Facial Nerve ◽

Cranial Nerves ◽

Surgical Excision ◽

Hearing Preservation ◽

Middle Fossa ◽

Middle Fossa Approach ◽

Translabyrinthine Approach ◽

Number Of Patients ◽

Facial Nerve Monitoring ◽

Facial Function

Between March 1966 and September 1992, 1400 acoustic neuromas were treated in Paris, France, by surgical excision. The findings over the last 7 years are presented. The translabyrinthine approach has been used in more than 85% of cases. Where hearing preservation is attempted, the middle fossa approach has been adopted for intracanilicular tumors and the retrosigmoid approach for small tumors extending into the cerebellopontine angle, in which the fundus of the internal meatus is free of tumor. The main goal is to achieve a grade I or II result in facial function within 1 month of surgery. Results improved during 1991 after the introduction of continuous facial nerve monitoring and the use of the Beaver mini-blade for dissection of tumor from nerve. With these techniques, facial function at grade I or II at 1 month improved from 20% to 52% for large tumors (larger than 3 cm), from 42% to 81% for medium tumors (2 to 3 cm), and from 70% to 92% for small tumors (up to and including 2 cm extracanalicular). The facial nerve was at greater risk using the retrosigmoid or middle fossa approaches than by the translabyrinthine route. Since 1985, success in hearing preservation has changed little, with useful hearing being preserved in 38.2% of cases operated on by means of the retrosigmoid route and 36.4% of cases after the middle fossa approach. In older patients with good hearing and small tumors, observation with periodic MRI scanning is recommended. Despite earlier diagnosis, the number of patients suitable for hearing preservation surgery remains very limited and careful selection is required. Trigeminal nerve signs were present in 20% of cases preoperativey, in 10% postoperatively, and recovered spontaneously. Palsies of the other cranial nerves after surgery were much rarer and were as follows: sixth nerve (abducens), 0.5%; ninth nerve (glossopharyngeal), 1.4%; and tenth nerve (vagus), 0.7%. The importance of preservation of function of the nervus intermedius of Wrisberg is stressed. These results emphasize the advantages of the translabyrinthine approach, offering greater security to the facial nerve and lower morbidity.

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