Using the Arcuate Eminence–Trigeminal Notch Line to Localize the Anterior Wall of the Internal Auditory Canal in a Subtemporal Approach: An Anatomical Study

Author(s):  
Haifeng Yang ◽  
Mengjun Li ◽  
Ge Chen ◽  
Jiantao Liang ◽  
Yuhai Bao ◽  
...  

Abstract Background This article aims to describe the regional anatomy of the anterior end of the arcuate eminence, the lateral end of the trigeminal notch, and the line connecting the two (i.e., the arcuate eminence–trigeminal notch line [ATL]) and to determine whether the ATL could be used as a landmark for localizing the internal auditory canal (IAC). Methods Twenty sides of the middle cranial fossae were examined. The anterior end of the arcuate eminence, the lateral end of the trigeminal notch, the ATL, and other crucial structures were exposed. The relevant distance and angle of related structures in the anterior wall of the petrosal bone were measured. Results The anterior end of the arcuate eminence and the lateral end of the trigeminal notch could be identified in all specimens. The anterior end of the arcuate eminence lay over the geniculate ganglia and the vestibule area, and could be visualized directly or determined from the intersection of the long axes of the greater superficial petrosal nerve and arcuate eminence. On the petrous ridge, the lateral end of the trigeminal notch was also the transitional point of the suprameatal tubercle and trigeminal notch. The ATL corresponded to the projection of the anterior wall of the IAC on the anterior surface of the petrous bone. Conclusion The ATL corresponded to the projection of the anterior wall of the IAC on the anterior petrous surface and could be used as an alternative landmark for localizing the anterior wall of the IAC.

2007 ◽  
Vol 107 (1) ◽  
pp. 181-184 ◽  
Author(s):  
Burak Sade ◽  
Joung H. Lee

✓Facial nerve schwannomas can occur anywhere from the internal auditory canal to the parotid gland. Schwannomas arising from the greater superficial petrosal nerve are exceedingly rare. The authors report the case of a 63-year-old woman who presented with a selective low-frequency hearing loss of 3 weeks' duration. Neurological examination demonstrated a House–Brackmann Grade II facial paresis and asymmetrical hearing loss on the left side. Audiometric evaluation showed a significant loss of low-frequency hearing with a speech reception threshold (SRT) of 30 dB and a speech discrimination score (SDS) of 88% on the left side. Magnetic resonance imaging revealed a 2.4-cm enhancing left middle fossa mass. Near-complete resection was performed via a left temporal craniotomy. The tumor was located in the Glasscock triangle and had invaded the petrous bone overlying the cochlea. A very small piece of the tumor over the cochlea was left in order to preserve hearing. A postoperative audiogram showed significant improvement in the patient's hearing, with an SRT of 20 dB and an SDS of 100%. The histological findings were consistent with schwannoma. The patient experienced postoperative improvement of hearing function despite cochlear involvement, which has previously been reported as an unfavorable factor for postoperative hearing outcome in facial nerve schwannomas.


1999 ◽  
Vol 113 (8) ◽  
pp. 717-720 ◽  
Author(s):  
Maged B. Naguib ◽  
Mario Sanna

AbstractThis work describes the exposure of the intrapetrous internal carotid artery (ICA) through the subtemporal approach. The anatomical details of 25 fresh temporal bones were studied and provided the initial background for this procedure. Bone drilling in the meatal plane anterior to the internal auditory canal could create a four-sided quadrangular area. The exposure of the ICA through this area was applied on three occasions. It proved safe as regards the surrounding structures and also provided an ample working space for the extirpation of tumours surrounding the artery.


Author(s):  
Udom Bawornvaraporn ◽  
Ali R. Zomorodi ◽  
Allan H. Friedman ◽  
Takanori Fukushima

2021 ◽  
pp. 1-7
Author(s):  
Robert C. Rennert ◽  
Michael G. Brandel ◽  
Jeffrey A. Steinberg ◽  
David D. Gonda ◽  
Rick A. Friedman ◽  
...  

OBJECTIVE The middle fossa transpetrosal approach to the petroclival and posterior cavernous sinus regions includes removal of the anterior petrous apex (APA), an area well studied in adults but not in children. To this end, the authors performed a morphometric analysis of the APA region during pediatric maturation. METHODS Measurements of the distance from the clivus to the internal auditory canal (IAC; C-IAC), the distance of the petrous segment of the internal carotid artery (petrous carotid; PC) to the mesial petrous bone (MPB; PC-MPB), the distance of the PC to the mesial petrous apex (MPA; PC-MPA), and the IAC depth from the middle fossa floor (IAC-D) were made on thin-cut CT scans from 60 patients (distributed across ages 0–3, 4–7, 8–11, 12–15, 16–18, and > 18 years). The APA volume was calculated as a cylinder using C-IAC (length) and PC-MPB (diameter). APA pneumatization was noted. Data were analyzed by laterality, sex, and age. RESULTS APA parameters did not differ by laterality or sex. APA pneumatization was seen on 20 of 60 scans (33.3%) in patients ≥ 4 years. The majority of the APA region growth occurred by ages 8–11 years, with PC-MPA and PC-MPB increasing 15.9% (from 9.4 to 10.9 mm, p = 0.08) and 23.5% (from 8.9 to 11.0 mm, p < 0.01) between ages 0–3 and 8–11 years, and C-IAC increasing 20.7% (from 13.0 to 15.7 mm, p < 0.01) between ages 0–3 and 4–7 years. APA volume increased 79.6% from ages 0–3 to 8–11 years (from 834.3 to 1499.2 mm3, p < 0.01). None of these parameters displayed further significant growth. Finally, IAC-D increased 51.1% (from 4.3 to 6.5 mm, p < 0.01) between ages 0–3 and adult, without significant differences between successive age groups. CONCLUSIONS APA development is largely complete by the ages of 8–11 years. Knowledge of APA growth patterns may aid approach selection and APA removal in pediatric patients.


1993 ◽  
Vol 102 (2) ◽  
pp. 100-107 ◽  
Author(s):  
Steven D. Rauch ◽  
Wen-Zhuang Xv ◽  
Joseph B. Nadol

The suboccipital-retrosigmoid approach to the internal auditory canal and cerebellopontine angle is being used with increasing frequency for neurotologic surgery, including vestibular nerve section and resection of acoustic neuroma. It offers wide exposure of the cerebellopontine angle and the cranial nerve VII—VIII complex as it courses from the brain stem to the temporal bone. Exposure of the internal auditory canal can be achieved by removing its posterior bony wall. Safe utilization of this approach requires familiarity with the variable position of structures within the petrous bone, including the lateral venous sinus and jugular bulb. We report here a case in which bleeding resulted from injury to a high jugular bulb during surgical exposure of the internal auditory canal via the suboccipital route and discuss the regional anatomy of the jugular bulb based on study of 378 consecutive temporal bone specimens from the collection of the Massachusetts Eye and Ear Infirmary. High jugular bulb was defined as encroachment of the dome of the bulb within 2 mm of the floor of the internal auditory canal. Forty-six percent of scoreable specimens met this criterion. However, when donors less than 6 years of age were excluded, a high jugular bulb was identified in 63% of specimens. Relevance to neurotologic surgery of the posterior fossa is presented.


2020 ◽  
pp. 86-94
Author(s):  
K. M. Diab ◽  
O. S. Panina ◽  
O. A. Pashchinina

Introduction. Petrous temporal bone (PTB) cholesteatoma is an epidermal cyst, which is the result of uncontrolled growth of keratinizing squamous epithelium in the petrous part of the temporal bone. Cholesteatoma is classified into congenital, acquired, and iatrogenic.Objective. To discuss the classification of infralabyrinthine petrous bone cholesteatoma (PBC), add modified classificationand to propose adequate differential surgical management.Methods. The setting was a National Medical Scientific Center of Otorhinolaryngology FMBA (Russia). The data of 14 patients who underwent surgery for different variations of infralabyrinthine PBC from 2017 till 2020 were analyzed and included into the study (with respect to localization type of the approach used, complications, recurrences and outcome). The follow-up period ranged from 6 to 34 months with a median of 18 months.Results. Based on preoperative CT scans and intraoperative findings a Scale of Cholesteatoma extension CLIF(APO) and Modified classification of infralabyrinthine cholesteatoma (in relation to mastoid segment of the facial nerve) are proposed. The scale includes the main anatomical structures of the temporal bone and the adjacent parts of the occipital and sphenoid bones, which may be involved in the cholesteatoma process: cochlea, vestibule and semicircular canals, internal auditory canal, jugular foramen, bony chanal of the internal carotid artery, petrous apex, occipital condyle. Based on the modified classification and scale we present an algorithm for decision making and surgical approach choosing.Conclusion. The implementation of the Scale of Cholesteatoma Extension in Otology and Radiology practice will allow to preoperatively diagnose the extension of PBC, unify the data of the localization of cholesteatoma; allows standardization in reporting and continuity at all stages of treatment. The modified classification proposed by us in this article facilitate the algorithm for selecting the type of surgical approach and determine whether to perform less aggressive combined microscopic approaches with endoscopic control.


2021 ◽  
Vol 2 (18) ◽  
Author(s):  
Masato Ito ◽  
Yoshinori Higuchi ◽  
Kentaro Horiguchi ◽  
Shigeki Nakano ◽  
Shinichi Origuchi ◽  
...  

BACKGROUND Anatomical variations, such as high jugular bulbs and air cell development in the petrosal bone, should be evaluated before surgery. Most bone defects in the internal auditory canal (IAC) posterior wall are observed in the perilabyrinthine cells. An aberrant vascular structure passing through the petrous bone is rare. OBSERVATIONS A 48-year-old man presented with a right ear hearing disturbance. Magnetic resonance imaging revealed a 23-mm contrast-enhancing mass in the right cerebellopontine angle extending into the IAC, consistent with a right vestibular schwannoma. Preoperative bone window computed tomographic scans showed bone defects in the IAC posterior wall, which ran farther posteroinferiorly in the petrous bone, reaching the medial part of the jugular bulb. The tumor was accessed via a lateral suboccipital approach. There was no other major vein in the cerebellomedullary cistern, except for the vein running from the brain stem to the IAC posterior wall. To avoid complications due to venous congestion, the authors did not drill out the IAC posterior wall or remove the tumor in the IAC. LESSONS Several aberrant veins in the petrous bone are primitive head sinus remnants. Although rare, their surgical implication is critical in patients with vestibular schwannomas.


2020 ◽  
Vol 42 (5) ◽  
pp. 567-575
Author(s):  
Filippo Gagliardi ◽  
Martina Piloni ◽  
Michele Bailo ◽  
Nicola Boari ◽  
Francesco Calvanese ◽  
...  

2007 ◽  
Vol 86 (8) ◽  
pp. 474-481 ◽  
Author(s):  
Hamid R. Djalilian ◽  
Kunal H. Thakkar ◽  
Sanaz Hamidi ◽  
Aaron G. Benson ◽  
Mahmood F. Mafee

We conducted a study to establish standardized measurements of the common anatomic landmarks used during surgery via the middle cranial fossa approach. Results were based on high-resolution computed tomography (CT) images of 98 temporal bones in 54 consecutively presenting patients. Measurements were obtained with the assistance of the standard PACS (picture archiving and communication system) software. We found that the superior semicircular canal (SSC) dome was not the highest point on the temporal bone (i.e., the arcuate eminence) in 78 of the temporal bone images (79.6%). Pneumatization above the SSC and above the internal auditory canal (IAC) was found in 27 (27.6%) and 39 (39.8%) temporal bone images, respectively. The anterior wall of the external auditory canal was always anterior to the anterior wall of the IAC. The mean angles between the SSC and the posterior and anterior walls of the IAC were 42.3° and 60.8°, respectively. We also measured other distances, and we compared our findings with those published by others. We hope that the results of our study will help surgeons safely and rapidly locate anatomic landmarks when performing surgery via the middle cranial fossa approach.


2019 ◽  
Vol 80 (S 03) ◽  
pp. S287-S287
Author(s):  
Walter C. Jean ◽  
Kyle Mueller ◽  
H. Jeffrey Kim

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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