Hearing Improvement Following Middle Cranial Fossa Floor Defect Repair Utilizing a Modified Middle Fossa Approach and Reconstructive Techniques

Objective This video was aimed to demonstrate the middle fossa approach for the resection of an intracanalicular vestibular schwannoma. Design Present study is a video case report. Setting The operative video is showing a microsurgical resection. Participant The patient was a 59-year-old man who presented with worsening headache and right-side hearing loss. He was found to have a right intracanalicular vestibular schwannoma. After weighing risks and benefits, he chose surgery to remove his tumor. Since his hearing remained “serviceable,” a middle fossa approach was chosen. Main Outcome Measures Pre- and postoperative patient photographs evaluated the muscles of facial expression as a marker for facial nerve preservation. Results A right middle fossa craniotomy was performed which allowed access to the floor of the middle cranial fossa. The greater superficial petrosal nerve (GSPN) and arcuate eminence were identified. Using these two landmarks, the internal acoustic canal (IAC) was localized. After drilling the petrous bone, the IAC was unroofed. The facial nerve was identified by stimulation and visual inspection and the tumor was separated from it with microsurgical dissection. In the end, the tumor was fully resected. Both the facial and cochlear nerves were preserved. Postoperatively, the patient experienced no facial palsy and his hearing is at baseline. Conclusion With radiosurgery gaining increasing popularity, patients with intracanalicular vestibular schwannomas are frequently treated with it, or are managed with observation. The middle fossa approach is therefore becoming a “lost art,” but as demonstrated in this video, remains an effective technique for tumor removal and nerve preservation.The link to the video can be found at: https://youtu.be/MD6o3DF6jYg.

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Acquired Middle Cranial Fossa Fistulas

Neurosurgery ◽

10.1227/00006123-197910000-00011 ◽

1979 ◽

Vol 5 (4) ◽

pp. 466-472 ◽

Cited By ~ 64

Author(s):

Benjamin Kaufman ◽

Howard Yonas ◽

Robert J. White ◽

Clinton F. Miller

Keyword(s):

Cerebrospinal Fluid ◽

Normal Population ◽

Normal Pressure ◽

Middle Cranial Fossa ◽

Csf Leak ◽

Middle Fossa ◽

Middle Fossa Approach ◽

Cranial Fossa ◽

Definition Of ◽

Base Of The Skull

Abstract To the accepted classification of three types of normal pressure, nontraumatic cerebrospinal fluid (CSF) fistulas, we would add “acquired.” This type of CSF fistula tends to occur from the middle cranial fossa because of the enlargement of “pitholes” that are normally present in its anterior medial aspect. The enlargement of these bony defects is due to normal intracranial pressure variations that, not uncommonly, create meningoceles and meningoencephaloceles. A portion of the floor of this area is aerated in up to 10% of the normal population by the lateral recess of the sphenoid sinus, the pterygoid recess. Thus, this area has the potential to act as a pathway between the middle fossa and the paranasal sinuses, allowing cerebrospinal fluid to pass into the sinuses. Isotope and computerized tomographic studies are helpful in the localization of such a CSF leak. Tomography of the base of the skull, however, is essential for the ideal definition of possible routes of fistulization. If there is any question of the presence of a middle fossa fistula, these studies can show whether the floor of this area is pneumatized and whether there are any defects in the floor. The treatment of such a fistula should include generalized reinforcement of the floor of the anterior middle fossa by a middle fossa approach. If any doubt exists as to the site of leakage (anterior or middle fossa), the minimal surgical procedure should include exploration of both areas via a frontotemporal craniotomy.

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Middle cranial fossa approach for acoustic neuroma

Neurosurgical Focus: Video ◽

10.3171/2021.7.focvid21124 ◽

2021 ◽

Vol 5 (2) ◽

pp. V12

Author(s):

Paul W. Gidley ◽

Joel Z. Passer ◽

Joshua C. Page ◽

Franco DeMonte

Keyword(s):

Acoustic Neuroma ◽

Hearing Preservation ◽

Middle Cranial Fossa ◽

Middle Fossa ◽

Surgical Indications ◽

Total Resection ◽

Technical Aspects ◽

Middle Fossa Approach ◽

Acoustic Neuromas ◽

Cranial Fossa

The middle fossa approach for the resection of small acoustic neuromas is a viable, but underutilized treatment modality with the goal of hearing preservation. The authors aim to demonstrate this approach and its nuances through this video presentation. A 38-year-old man presented with an incidentally discovered small, intracanalicular acoustic neuroma that was initially observed, but growth was noted. The patient had good hearing, and therefore a hearing preservation approach was offered. A gross-total resection was achieved, and the patient maintained good hearing postoperatively. This video demonstrates relevant anatomy, surgical indications, technical aspects of resection, including reconstruction, and postoperative outcomes. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21124

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The orbitopterygoid corridor as a deep keyhole for endoscopic access to the paranasal sinuses and clivus

Journal of Neurosurgery ◽

10.3171/2020.3.jns2022 ◽

2020 ◽

pp. 1-10

Author(s):

Kenichi Oyama ◽

Kentaro Watanabe ◽

Shunya Hanakita ◽

Pierre-Olivier Champagne ◽

Thibault Passeri ◽

...

Keyword(s):

Nasal Cavity ◽

Skull Base ◽

Paranasal Sinuses ◽

Middle Cranial Fossa ◽

The Body ◽

Middle Fossa Approach ◽

Alternative Approach ◽

Endoscopic Assistance ◽

Skull Base Lesions ◽

Cranial Fossa

OBJECTIVEThe anteromedial triangle (AMT) is the triangle formed by the ophthalmic (V1) and maxillary (V2) nerves. Opening of this bony space offers a limited access to the sphenoid sinus (SphS). This study aims to demonstrate the utility of the orbitopterygopalatine corridor (OPC), obtained by enlarging the AMT and transposing the contents of the pterygopalatine fossa (PPF) and V2, as an entrance to the SphS, maxillary sinus (MaxS), and nasal cavity.METHODSFive formalin-injected cadaveric specimens were used for this study (10 approaches). A classic pterional approach was performed. An OPC was created through the inferior orbital fissure, between the orbit and the PPF, by transposing the PPF inferiorly. The extent of the OPC was measured using neuronavigation and manual measurements. Two illustrative cases using the OPC to access skull base tumors are presented in the body of the article.RESULTSVia the OPC, the SphS, MaxS, ethmoid sinus (EthS), and nasal cavity could be accessed. The use of endoscopic assistance through the OPC achieved better visualization of the EthS, SphS, MaxS, clivus, and nasal cavity. A significant gain in the area of exposure could be achieved using the OPC compared to the AMT (22.4 mm2 vs 504.1 mm2).CONCLUSIONSOpening of the AMT and transposition of V2 and the contents of the PPF creates the OPC, a potentially useful deep keyhole to access the paranasal sinuses and clival region through a middle fossa approach. It is a valuable alternative approach to reach deep-seated skull base lesions infiltrating the cavernous sinus and middle cranial fossa and extending into the paranasal sinus.

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Evaluating Intracochlear Trauma after Cochlear Implant Electrode Insertion through Middle Fossa Approach in Temporal Bones

Otolaryngology ◽

10.1177/0194599817739837 ◽

2017 ◽

Vol 158 (2) ◽

pp. 350-357 ◽

Cited By ~ 2

Author(s):

Juan Carlos Cisneros Lesser ◽

Rubens de Brito ◽

Graziela de Souza Queiroz Martins ◽

Eloisa Maria Mello Santiago Gebrim ◽

Ricardo Ferreira Bento

Keyword(s):

Cochlear Implant ◽

Round Window ◽

Middle Cranial Fossa ◽

Middle Fossa ◽

Insertion Depth ◽

Middle Fossa Approach ◽

Basal Turn ◽

Fresh Frozen ◽

Electrode Insertion ◽

Temporal Bones

Objective To evaluate cochlear trauma after cochlear implant insertion through a middle fossa approach by means of histologic and imaging studies in temporal bones. Study Design Prospective cadaveric study. Setting University-based temporal bone laboratory. Subjects and Methods Twenty fresh-frozen temporal bones were implanted through a middle cranial fossa basal turn cochleostomy. Ten received a straight electrode and 10 a perimodiolar electrode. Samples were fixed in epoxy resin. Computed tomography (CT) scans determined direction, depth of insertion, and the cochleostomy to round window distance. The samples were polished by a microgrinding technique and microscopically visualized to evaluate intracochlear trauma. Descriptive and analytic statistics were performed to compare both groups. Results The CT scan showed intracochlear insertions in every bone, 10 directed to the middle/apical turn and 10 to the basal turn. In the straight electrode group, the average number of inserted electrodes was 12.3 vs 15.1 for the perimodiolar group ( U = 78, P = .0001). The median insertion depth was larger for the perimodiolar group (14.4 mm vs 12.5 mm, U = 66, P = .021). Only 1 nontraumatic insertion was achieved and 14 samples (70%) had important trauma (Eshraghi grades 3 and 4). No differences were identified comparing position or trauma grades for the 2 electrode models or when comparing trauma depending on the direction of insertion. Conclusion The surgical technique allows a proper intracochlear insertion, but it does not guarantee a correct scala tympani position and carries the risk of important trauma to cochlear microstructures.

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Euclidean Relationship between the Superior Semicircular Canal and the Arcuate Eminence

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0039-1683432 ◽

2019 ◽

Vol 81 (02) ◽

pp. 165-171 ◽

Cited By ~ 1

Author(s):

Aida Nourbakhsh ◽

Yang Tang ◽

Brian S. DiPace ◽

Daniel H. Coelho

Keyword(s):

Semicircular Canal ◽

Euclidean Distance ◽

Three Dimensional ◽

Middle Cranial Fossa ◽

Surgical Anatomy ◽

P Value ◽

Middle Fossa ◽

Superior Semicircular Canal ◽

Cranial Fossa ◽

Academic Teaching Hospital

Abstract Objective This study was aimed to better characterize the surgical anatomy of the floor of the middle cranial fossa using three dimensional Euclidean relationships between the arcuate eminence (AE), the superior semicircular canal (SSC), and the geniculate ganglion (GG). Study Design Submillimeter distances were recorded from computed tomography (CT) scans of 50 patients (100 sides). The AE, apex of the SSC, and the GG were identified and three dimensional distances measured. Setting The study was conducted at a tertiary academic teaching hospital. Main Outcome Measures In this study, Euclidean distance was obtained from AE to SSC by using a fixed anatomical landmark (GG) as the origin. Results On average, the AE is 2.1 ± 0.3 mm lateral, 2.5 ± 0.1 mm superior, and 2.1 ± 0.3 posterior to the SSC. Thirty percent (30/100) of patients had an AE that was less than 2 mm superior to SSC. The AE was medial to the SCC in 13% samples and anterior to the SSC in 18% samples. The results also show that there was no difference in mean distance between sides (1.08 mm; 95% confidence interval [CI] = − 2.67–0.52; p-value = 0.29) or gender (0.56 mm; 95% CI = − 1.34, 2.45; p-value = 0.86). Conclusions This study represents a comprehensive analysis of the relational anatomy of the floor of the middle fossa to date. In quantifying relationships between the AE, SSC, and GG, and by understanding the variability of these relationships in some planes, the middle fossa surgeon can feel more comfortable with this most challenging approach.

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Hearing preservation despite labyrinthectomy for resection of giant cholesteatoma with middle fossa extension

The Journal of Laryngology & Otology ◽

10.1017/s0022215100140812 ◽

1998 ◽

Vol 112 (5) ◽

pp. 472-475 ◽

Cited By ~ 5

Author(s):

F. Rapado ◽

N. Fergie ◽

R. T. Ramsden

Keyword(s):

Middle Ear ◽

Bone Conduction ◽

Mass Effect ◽

Hearing Preservation ◽

Middle Cranial Fossa ◽

Middle Fossa ◽

Bone Conduction Threshold ◽

Acquired Cholesteatoma ◽

Cranial Fossa ◽

Middle Ear Cleft

AbstractA case is described of an extensive acquired cholesteatoma of the middle ear cleft which had invaded the middle cranial fossa and produced a mass effect on the temporal lobe. It had also extended into the labyrinth without causing elevation in the bone conduction threshold. Furthermore, even after total bony labyrinthectomy, there was very little elevation in these thresholds. The literature relating to hearing preservation after labyrinthectomy is reviewed.

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Temporal Lobe Encephalocele Appearing as a Lytic Lesion of the Skull Base and Pterygoid Process

Ear Nose & Throat Journal ◽

10.1177/014556130308200411 ◽

2003 ◽

Vol 82 (4) ◽

pp. 269-275 ◽

Cited By ~ 7

Author(s):

William E. Bolger ◽

Christine Reger

Keyword(s):

Skull Base ◽

Brain Tissue ◽

Unusual Case ◽

Middle Cranial Fossa ◽

Ethmoid Sinus ◽

Lytic Lesion ◽

Middle Fossa ◽

Pterygoid Process ◽

Cranial Fossa ◽

Uncommon Condition

Meningoencephalocele is an uncommon condition in which brain tissue, meninges, or both protrude through a defect in the anterior cranial fossa and into the ethmoid sinus or nasal cavity. Much less often, brain tissue, meninges, or both protrude through a defect in the middle cranial fossa and into the sphenoid sinus. We report an unusual case of a middle fossa encephalocele that appeared as a lytic lesion of the skull base. The patient was treated successfully via a unique endoscopic transpterygoid approach—that is, an endoscopic approach through the maxillary sinus and pterygopalatine fossa and into the pterygoid process.

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The Course of the Lesser Petrosal Nerve on the Middle Cranial Fossa

Operative Neurosurgery ◽

10.1227/01.neu.0000289707.49684.a3 ◽

2007 ◽

Vol 61 (suppl_3) ◽

pp. ONS-15-ONS-23 ◽

Cited By ~ 10

Author(s):

Yukinari Kakizawa ◽

Hiroshi Abe ◽

Yutaka Fukushima ◽

Kazuhiro Hongo ◽

Hatem El-Khouly ◽

...

Keyword(s):

Skull Base ◽

Middle Cranial Fossa ◽

Surgical Approaches ◽

Geniculate Ganglion ◽

Middle Fossa ◽

Greater Petrosal Nerve ◽

Three Bundles ◽

Thin Bone ◽

Cranial Fossa

Abstract Objective: The course of the lesser petrosal nerve is not well understood and may be confused with the course of the greater petrosal nerve during middle fossa surgery. The objective was to examine the course of the lesser petrosal nerve along the floor of the middle cranial fossa from the region of the geniculate ganglion to its outlet from the skull base. There are no studies focused on the course of this nerve in relationship to the floor of the middle cranial fossa. Methods: Twenty middle fossae from adult cadaveric specimens were examined using 3 to 40× magnification. Results: The lesser petrosal nerve was partially exposed on the floor of the middle fossa without drilling in 75% of the middle fossae and totally covered by thin bone in 25%. It crossed the floor anterior to the greater petrosal nerve and exited the middle fossa through the canaliculus innominatus in 14 cases, foramen spinosum in 3 cases, and the sphenopetrosal suture in 3 cases. The course of the lesser petrosal nerve has been shown in textbooks to be parallel to the greater petrosal nerve. However, the lesser and greater petrosal nerves diverged in the area medial to the geniculate ganglion in 90% of middle fossae with the angle of divergence averaging 11.6 degrees. The course of the lesser petrosal nerve was divided into three patterns based on the site of confluence of the three bundles of fibers forming the nerve. Conclusion: The relationships of the lesser petrosal nerve in the middle cranial fossa have been described. An understanding of these relationships will reduce the likelihood of it being confused with the greater petrosal nerve during surgical approaches to the middle fossa.

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