Maturation of the anterior petrous apex: surgical relevance for performance of the middle fossa transpetrosal approach in pediatric patients

2021 ◽  
pp. 1-7
Author(s):  
Robert C. Rennert ◽  
Michael G. Brandel ◽  
Jeffrey A. Steinberg ◽  
David D. Gonda ◽  
Rick A. Friedman ◽  
...  
Keyword(s):  
Pediatric Patients ◽  
Internal Carotid ◽  
Age Groups ◽  
Internal Auditory Canal ◽  
Petrous Bone ◽  
Growth Patterns ◽  
Ct Scans ◽  
Petrous Apex ◽  
Middle Fossa ◽  
Region Growth

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.

Microsurgical Anatomy of the Endoscopy-Assisted Retrosigmoid Intradural Suprameatal Approach to the Meckel's Cave

2021 ◽  
Author(s):  
Yuanzhi Xu ◽  
Benjamin K Hendricks ◽  
Maximiliano Alberto Nunez ◽  
Ahmed Mohyeldin ◽  
Juan C Fernandez-Miranda ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Internal Auditory Canal ◽  
Semicircular Canals ◽  
Petrous Apex ◽  
Microsurgical Anatomy ◽  
Meckel’S Cave ◽  
Meckel's Cave ◽  
Trigeminal Root

Abstract BACKGROUND Understanding the microsurgical anatomical features of the endoscopy-assisted retrosigmoid intradural suprameatal approach (RISA) is critical for surgeons treating petroclival tumors or lesions in the cerebellopontine region that extend into Meckel's cave. OBJECTIVE To evaluate increased exposure for Meckel's cave in the RISA and assess the surgical landmarks for this approach. METHODS A standard retrosigmoid craniotomy to the cerebellopontine region was performed in 4 cadaveric specimens (8 hemispheres) with microscope-assisted endoscopy. The length and depth of the drilling region from the suprameatal tubercle to the petrous apex were analyzed. After opening Meckel's cave and mobilizing the trigeminal root completely, the landmarks for this approach were investigated. RESULTS The endoscopy-assisted RISA facilitates mobilization of the trigeminal root and enhances surgical exposure in the region of Meckel's cave and the petrous apex with increases of 10.1 ± 1.3 mm in depth, 21.4 ± 3.2 mm in length, and 6.4 ± 0.6 mm in height. The posterior and superior semicircular canals, internal auditory canal, superior petrous sinus, and internal carotid artery (petrous segment) served as important landmarks for this approach. One case illustration is presented to describe the application of this approach. CONCLUSION The RISA is suitable mainly for lesions in the posterior fossa that extend into Meckel's cave. The endoscopy-assisted reach optimizes accessibility to the petrous apex region, obviates the need for extensive drilling, and decreases the risk of internal carotid artery injury. Better realization and recognition of microsurgical landmarks and parameters of this approach are crucial for successful outcomes.

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

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.

scholarly journals Computed tomography morphometric analysis of anterior instrumentation in the pediatric thoracic spine

2016 ◽  
Vol 17 (4) ◽  
pp. 504-509
Author(s):  
Yao Li ◽  
Zhonghai Shen ◽  
Xiangyang Wang ◽  
Yongli Wang ◽  
Hongming Xu ◽  
...  
Keyword(s):  
Pediatric Patients ◽  
Reference Data ◽  
Age Groups ◽  
Ct Scans ◽  
Thoracic Vertebrae ◽  
Pediatric Age ◽  
Anterior Instrumentation ◽  
Age Related ◽  
Thoracic Spinal ◽  
Coronal Section

OBJECT The authors' goal in this paper was to quantify reference data on the dimensions and relationships of the maximum posterior screw angle and the thoracic spinal canal in different pediatric age groups. METHODS One hundred twelve pediatric patients were divided into 4 age groups, and their thoracic vertebrae were studied on CT scans. The width, depth, and maximum posterior screw angles with different screw entrance points were measured on a Philips Brilliance 16 CT. The statistical analysis was performed using the Student t-test and Pearson's correlation analysis. RESULTS The width and depth of the thoracic vertebrae increased from T-5 to T-12. The width ranged from 18.5 to 37.1 mm, while the depth ranged from 16.1 to 28.2 mm. The maximum posterior screw angle decreased from T-5 to T-12 in all groups. The ranges and mean angles at the entrance points were as follows: initial entrance point, 6.9° to 12.3° with a mean angle of 9.1°; second entrance point, 20.6° to 27.0° with a mean angle of 24.2°; and third entrance point, 29.2° to 37.5° with a mean angle of 33.7°. There were no significant age-related differences noted for the maximum posterior screw angles. CONCLUSIONS The angle decreased from T-5 to T-12. No significant age-related differences were noted in the maximum posterior screw angles. Screws should be placed between the initial and second points and parallel to the coronal section or at a slight anterior orientation.

scholarly journals Modified classification of infralabyrinthie cholesteatoma and scale of cholesteatoma extention

2020 ◽  
pp. 86-94
Author(s):  
K. M. Diab ◽  
O. S. Panina ◽  
O. A. Pashchinina
Keyword(s):  
Temporal Bone ◽  
Surgical Approach ◽  
Internal Auditory Canal ◽  
Petrous Bone ◽  
Jugular Foramen ◽  
Petrous Apex ◽  
Occipital Condyle ◽  
Epidermal Cyst ◽  
Scientific Center

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.

scholarly journals Transzygomatic extended middle fossa approach for upper petroclival skull base lesions

2008 ◽  
Vol 25 (6) ◽  
pp. E5 ◽  
Author(s):  
Jin-cheng Zhao ◽  
James K. Liu
Keyword(s):  
Skull Base ◽  
Internal Auditory Canal ◽  
Direct Access ◽  
Petrous Apex ◽  
Middle Fossa ◽  
Middle Fossa Approach ◽  
Trigeminal Root ◽  
Skull Base Lesions ◽  
Anterior Petrosectomy ◽  
Surgical Corridor

Central skull base lesions in the upper retroclival and petroclival regions can be challenging to access because of their location anterior to the brainstem. Several transpetrosal approaches have been developed to access the petroclival junction, including anterior petrosal (anterior petrosectomy), posterior petrosal (retrolabyrinthine, translabyrinthine, transcochlear), and combined petrosal approaches. The anterior petrosal approach is best suited for upper petroclival lesions located anterior and superior to the internal auditory canal and superior to the inferior petrosal sinus. This approach provides direct access to the anteromedial cerebellopontine angle, petrous apex, Meckel cave, and ventrolateral brainstem between the trigeminal root and the facial nerve. The authors describe their modification of an anterior petrosal approach, the so-called transzygomatic extended middle fossa approach, which incorporates a zygomatic osteotomy, anterior mobilization of the V3, and extensive middle fossa drilling. This exposure provides a wider surgical corridor for direct view of the clivus and ventral brainstem.

Endoscopic transmastoid posterior petrosal approach for locally aggressive tumors in the petrous part of the temporal bone involving the internal auditory canal, jugular foramen, and hypoglossal canal

2020 ◽  
Vol 133 (4) ◽  
pp. 1248-1260
Author(s):  
Masahiro Shin ◽  
Hirotaka Hasegawa ◽  
Satoru Miyawaki ◽  
Akinobu Kakigi ◽  
Tsuguto Takizawa ◽  
...  
Keyword(s):  
Skull Base ◽  
Internal Carotid ◽  
Internal Auditory Canal ◽  
Petrous Bone ◽  
Jugular Foramen ◽  
Occipital Condyle ◽  
Skull Base Tumors ◽  
Hypoglossal Canal ◽  
Air Cells ◽  
Mastoid Air Cells

OBJECTIVEThe posterior petrosal approach is an established surgical method offering wide access to skull base lesions through mastoid air cells. The authors describe their experience with the endoscopic transmastoid “posterior petrosal” approach (EPPAP) for skull base tumors involving the internal auditory canal (IAC), jugular foramen, and hypoglossal canal.METHODSThe EPPAP was performed for 7 tumors (3 chordomas, 2 chondrosarcomas, 1 schwannoma, and 1 solitary fibrous tumor). All surgical procedures were performed under endoscopic visualization with mastoidectomy. The compact bone of the mastoid air cells and posterior surface of the petrous bone are carefully removed behind the semicircular canals. When removal of cancellous bone is extended superomedially through the infralabyrinthine space, the surgeon can expose the IAC and petrous portion of the internal carotid artery to reach the petrous apex (infralabyrinthine route). When removal of cancellous bone is extended inferomedially along the sigmoid sinus, the surgeon can safely reach the jugular foramen (transjugular route). Drilling of the inferior surface of petrous bone is extended further inferoposteriorly behind the jugular bulb to approach the hypoglossal canal and parapharyngeal space through the lateral aspect of the occipital condyle (infrajugular route).RESULTSOf the 7 tumors, gross-total resection was achieved in 4 (57.1%), subtotal resection (> 95% removal) in 2 (28.6%), and partial resection (90% removal) in 1 (14.2%). Postoperatively, 2 of 3 patients with exudative otitis media showed improvement of hearing deterioration, as did 2 patients with tinnitus. Hypoglossal nerve palsy and swallowing difficulty were improved after surgery in 2 patients and 1 patient, respectively. In 1 patient with severe cranial nerve deficits before surgery, symptoms did not show any improvement.CONCLUSIONSThe authors present their preliminary experience with EPPAP for skull base tumors in the petrous part of the temporal bone and the lateral part of the occipital condyle involving the cranial nerves and internal carotid arteries. The microscope showed a higher-quality image and illumination in the low-power field. However, the endoscope could offer wider visualization of the surgical field and contribute to minimizing the size of the surgical pathways, necessity of brain retraction, and eventually the invasiveness of surgery. Thus, the EPPAP may be safe and effective for skull base tumors in the petrous region, achieving balance between the radicality and invasiveness of the skull base surgery.

Surgery of the Skull Base: Transcochlear Approach to the Petrous Apex and Clivus

1978 ◽  
Vol 86 (5) ◽  
pp. ORL-770-ORL-779 ◽  
Author(s):  
William F. House ◽  
Antonio De la Cruz ◽  
William E. Hitselberger
Keyword(s):  
Internal Carotid ◽  
Cranial Nerves ◽  
Internal Auditory Canal ◽  
Petrous Apex ◽  
Inferior Petrosal Sinus ◽  
Fallopian Canal ◽  
Vertebral Arteries ◽  
Stylomastoid Foramen ◽  
Superior Petrosal Sinus ◽  
Triangular Area

The Transcochlear approach is described for resection of lesions arising anterior or medial to the internal auditory canal as well as for those arising directly from the clivus. Through an extended complete mastoidectomy the facial nerve is totally decompressed and rerouted posteriorly from the stylomastoid foramen to the internal auditory canal. The fallopian canal, promontorium, and cochlea are removed anteriorly and medially as far as the internal carotid artery, obtaining exposure to a triangular area limited by the superior petrosal sinus, inferior petrosal sinus, carotid, and internal auditory canal, giving adequate exposure to the structures of the clivus and the midline (basilar artery, vertebral arteries, and the sixth cranial nerves).

Combined Endoscopic Endonasal and Contralateral Transmaxillary Approach for Petrous Cholesteatoma: 2-Dimensional Operative Video

2021 ◽  
Author(s):  
Wei-Hsin Wang ◽  
Ming-Ying Lan ◽  
Carl H Snyderman ◽  
Paul A Gardner
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Hearing Impairment ◽  
Internal Carotid ◽  
Video Recording ◽  
Internal Auditory Canal ◽  
Petrous Apex ◽  
Endoscopic Endonasal ◽  
The Right ◽  
Key Steps

Abstract This 59-yr-old man presented with headache, dizziness, diplopia, and right-side hearing impairment for years. The objective degree of hearing impairment was not available. Magnetic resonance imaging (MRI) showed a right petrous apex lesion centered behind the right petrous internal carotid artery and extending lateral to the medial aspect of the right internal auditory canal. A combined endoscopic endonasal and left contralateral transmaxillary (CTM) approach was performed, and gross-total resection was achieved. Peeling the cyst wall from the dura resulted in minor weeping. It was covered with a left-sided, vascularized nasoseptal flap. His dizziness and diplopia improved immediately after the surgery. Histopathology revealed an epidermoid cyst. In this surgical video, we demonstrate the key steps of the CTM approach for access to the petrous apex posterior to the petrous internal carotid artery (ICA).  The patient gave informed consent for surgery and video recording.

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