24 middle fossa, microsurgical of Microsurgical of petrous apex Microsurgical Anatomy of the Middle Fossa and Petrous Apex

Abstract Chordoma is not a benign disease. It grows invasively, has a high rate of local recurrence, metastasizes, and seeds in the surgical field.1 Thus, chordoma should be treated aggressively with radical resection that includes the soft tissue mass and the involved surrounding bone that contains islands of chordoma.2–5 High-dose radiation, commonly by proton beam therapy, is administered after gross total resection for long-term control. About half of chordoma cases occupy the cavernous sinus space and resecting this extension is crucial to obtain radical resection. Fortunately, the cavernous sinus proper extension is the easier part to remove and pre-existing cranial nerves deficit has good chance of recovery. As chordomas originate and are always present extradurally (prior to invading the dura), an extradural access to chordomas is the natural way for radical resection without brain manipulation. The zygomatic approach is key to the middle fossa, cavernous sinus, petrous apex, and infratemporal fossa; it minimizes the depth of field and is highly advantageous in chordoma located mainly lateral to the cavernous carotid artery.6–12 This article demonstrates the advantages of this approach, including the mobilization of the zygomatic arch alleviating temporal lobe retraction, the peeling of the middle fossa dura for exposure of the cavernous sinus, the safe dissection of the trigeminal and oculomotor nerves, and total control of the petrous and cavernous carotid artery. Tumor extensions to the sphenoid sinus, sella, petrous apex, and clivus can be removed. The patient is a 30-yr-old who consented for surgery.

Download Full-text

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

Operative Neurosurgery ◽

10.1093/ons/opab096 ◽

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.

Download Full-text

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

Journal of Neurosurgery ◽

10.3171/2021.3.jns202648 ◽

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.

Download Full-text

Microsurgical Resection of Trigeminal Schwannomas: 3-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opz097 ◽

2019 ◽

Vol 18 (1) ◽

pp. E18-E18

Author(s):

Duarte N C Cândido ◽

Marcio S Rassi ◽

Guilherme Henrique Weiler Ceccato ◽

Jean Gonçalves de Oliveira ◽

Luis A B Borba

Keyword(s):

Trigeminal Nerve ◽

Senior Author ◽

Petrous Apex ◽

Middle Fossa ◽

Middle Fossa Approach ◽

3 Dimensional ◽

History Of ◽

Nerve Paresis ◽

Microsurgical Resection ◽

The Right

Abstract Trigeminal schwannomas are benign lesions arising from the Schwann cells of the trigeminal nerve. This is an unusual tumor that accounts for less than 0.4% of intracranial pathologies, even though they are the second most frequent schwannoma after the vestibular schwannoma. The tumor spreads along the natural course of the V nerve at its cisternal portion, along the ganglion inside Meckel's cave or through its peripheral division. Even though the tumor can reach great size and become multicompartmental. We present a 51-yr-old woman, with an history of 3 mo of incapacitating facial pain, that was found on examination to be on the territory of the third division of the trigeminal nerve on the right side. The MRI depicted a large homogeneous enhancing lesion at the base of the right middle fossa with extension through the petrous apex to the most superior and medial part of the posterior fossa. The patient was operated by the senior author, through a middle fossa approach, dissecting between the two layers of the middle fossa dura (the apparent inner and the true outer layer of the cavernous sinus), the so called middle fossa “peeling”. We achieved total resection of the tumor, but the patient presented after surgery with facial nerve paresis. This is thought to be related to geniculate ganglion manipulation, as it was unprotect by bone at the middle fossa and the patient maintained lacrimal function (post-geniculate alteration). It resolved completely after 6 mo. The patient consented to publication of her images.

Download Full-text

Anterior Petrosal Approach for the Resection of a Petrous Apex Meningioma with Tentorial Infiltration

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0038-1677496 ◽

2019 ◽

Vol 80 (S 03) ◽

pp. S304-S304

Author(s):

Diego Mendez-Rosito

Keyword(s):

Trigeminal Neuralgia ◽

Free Edge ◽

Gross Total Resection ◽

Petrous Apex ◽

Anatomical Landmarks ◽

Middle Fossa ◽

Total Resection ◽

Middle Fossa Approach ◽

Anterior Petrosectomy ◽

Surgical Corridor

Objective The anterior petrosal approach is an extension of the middle fossa approach, characterized by drilling of the posteromedial triangle of the middle fossa. Drilling the Kawase's rhomboid creates a surgical corridor to the posterior fossa after splitting the tentorium. We present a case of a petrous apex meningioma invading the tentorium and causing trigeminal neuralgia. Results The patient was positioned in a Mayfield with the head rotated. A frontotemporal incision was done. A basal craniotomy was done to allow epidural dissection. The anatomical landmarks were identified. The surgical video is analyzed together with cadaveric dissections to highlight landmarks when doing an anterior petrosectomy. The tentorium was identified and the infiltrated region was coagulated and removed. The tentorium was sharply sectioned until the free edge of the tentorium was opened. The tumor in the petrous apex was identified and removed. The trigeminal nerve was decompressed and a gross total resection was achieved with resolution of the symptoms. Conclusion The anterior petrosal approach is a useful corridor to remove tumors in the petrous apex that infiltrate the tentorium. A thorough knowledge of the anatomical landmarks is crucial to identify and delineate the limits of the Kawase's rhomboid. After evaluating different surgical corridors, the anterior petrosal approach allows a gross total resection including the removal of the infiltrated tentorium and a resolution of the symptoms.The link to the video can be found at: https://youtu.be/p4KPUnM_bww.

Download Full-text

Intraspinosum Middle Meningeal Artery Ligation: A Simple Technique to Control Bleeding in the Middle Fossa During the Anterior Transpetrosal Approach

Operative Neurosurgery ◽

10.1093/ons/opw013 ◽

2017 ◽

Vol 13 (2) ◽

pp. 163-172

Author(s):

Shunsuke Shibao ◽

Hamid Borghei-Razavi ◽

Kazunari Yoshida

Keyword(s):

Facial Nerve ◽

Histological Study ◽

Middle Meningeal Artery ◽

Mandibular Nerve ◽

Petrous Apex ◽

Middle Fossa ◽

Foramen Ovale ◽

Anterior Transpetrosal Approach ◽

Nerve Paresis ◽

Meningeal Artery

Abstract BACKGROUND: Although the greater superficial petrosal nerve (GSPN) is an important landmark of the anterior transpetrosal approach (ATPA), bleeding from the interdural space around the foramen spinosum (FS), the GSPN, and the foramen ovale impedes the identification of the GSPN, during epidural dissection in the ATPA. OBJECTIVE: To describe the technique of intraspinosum middle meningeal artery (MMA) ligation, which enables us to control bleeding from the interdural space. METHODS: During epidural dissection, we identified the FS and partially drilled the lateral side of the FS. Next, we cut the convergence site of the neurovascular structures such as the MMA, middle meningeal vein, and the meningeal branch of the mandibular nerve with the periosteal dura within the FS and continued dural detachment epidurally to expose the petrous apex. Bleeding control around the FS and postoperative facial nerve paresis were assessed for 96 patients treated with the ATPA. Additionally, histological study was performed around the FS using Masson's trichrome stain. RESULTS: In all cases, in which this technique was used, bleeding from the interdural space was well controlled and no persistent facial nerve paresis was identified. In the histological study, we confirmed that the MMA, the middle meningeal vein, and the meningeal branch of the mandibular nerve converged into the FS and many venous channels existed in the interdural space around the FS and the foramen ovale. CONCLUSION: Intra-FS MMA ligation is an effective method for control of bleeding from the interdural space of the middle fossa during the ATPA.

Download Full-text

The Subtemporal Interdural Approach to Dumbbell-Shaped Trigeminal Schwannomas: Cadaveric Prosection

Operative Neurosurgery ◽

10.1227/01.neu.0000227590.70254.02 ◽

2006 ◽

Vol 59 (suppl_4) ◽

pp. ONS-270-ONS-278 ◽

Cited By ~ 9

Author(s):

Samy Youssef ◽

Eun-Young Kim ◽

Khaled M.A. Aziz ◽

Salah Hemida ◽

Jeffrey T. Keller ◽

...

Keyword(s):

Cleavage Plane ◽

Histological Study ◽

Petrous Apex ◽

Gasserian Ganglion ◽

Middle Fossa ◽

Meckel’S Cave ◽

Anterior Transpetrosal Approach ◽

Single Compartment ◽

Meckel's Cave ◽

Superior Petrosal Sinus

Abstract OBJECTIVE: Successful resection of dumbbell-shaped trigeminal schwannomas via a subtemporal interdural approach requires an understanding of both the anatomy related to the bone dissection of the petrous apex (Kawase's triangle or quadrilateral) and meningeal anatomy. We studied the meningeal anatomy related to this approach and describe the dural incisions and stepwise mobilization. METHODS: Meningeal anatomy around Meckel's cave and porus trigeminus was examined during the subtemporal interdural anterior transpetrosal approach in both sides of 15 cadaveric heads. Histological study of the Meckel's cave region was performed in two cadaveric heads. RESULTS: The Gasserian ganglion and trigeminal roots have two layers of dura propria on their dorsolateral surface: an inner layer from the posterior fossa dura propria that constitutes the dorsolateral wall of Meckel's cave and an outer layer from the dura propria of the middle fossa. The cleavage plane between these two layers continues distally as the cleavage plane between the epineural sheaths of the trigeminal divisions and the dura propria of the middle fossa. This cleavage plane serves as the anatomic landmark for the interdural exposure of the contents of Meckel's cave. The superior petrosal sinus is sectioned at the medial aspect of Kawase's triangle and reflected along with the porus trigeminus roof. CONCLUSION: Understanding the critical meningeal architecture in and around Meckel's cave allows experienced cranial neurosurgeons to develop a subtemporal interdural approach to dumbbell-shaped trigeminal schwannomas that effectively converts a multiple-compartment tumor into a single-compartment tumor. Dural incisions and stepwise mobilization complements our previous description of the bony dissection for this approach.

Download Full-text

Radiographic Anatomy of the Petrous Apex: A Study Related to the Middle Fossa Approach

Otolaryngology ◽

10.1016/j.otohns.2004.06.503 ◽

2004 ◽

Vol 131 (2) ◽

pp. P249-P250 ◽

Cited By ~ 1

Author(s):

Aaron Gabriel Benson ◽

Hamid R Djalilian

Keyword(s):

Petrous Apex ◽

Middle Fossa ◽

Middle Fossa Approach

Download Full-text

Endoscopic Endonasal Petrosectomy for Resection of Giant Petrous Apex Cholesterol Granuloma with Posterior and Middle Fossa Extension: Case Report

Skull Base ◽

10.1055/s-2009-1222344 ◽

2009 ◽

Vol 19 (01) ◽

Author(s):

Juan Fernandez-Miranda ◽

Victor Morera ◽

Rick Madhok ◽

Daniel Prevedello ◽

Paul Gardner ◽

...

Keyword(s):

Case Report ◽

Petrous Apex ◽

Cholesterol Granuloma ◽

Middle Fossa ◽

Endoscopic Endonasal

Download Full-text

Combined transmastoid middle fossa approach for giant cholesterol granuloma of the petrous apex: technique for “dual exhaust” drainage

Neurosurgical FOCUS ◽

10.3171/2014.v1.focus13417 ◽

2014 ◽

Vol 36 (v1supplement) ◽

pp. 1

Author(s):

James K. Liu ◽

Robert W. Jyung

Keyword(s):

Hearing Loss ◽

Facial Nerve ◽

Cyst Wall ◽

Petrous Apex ◽

Cholesterol Granuloma ◽

Middle Fossa ◽

Catheter Drainage ◽

Middle Fossa Approach ◽

Air Cells ◽

Cyst Cavity

Cholesterol granulomas are cystic lesions that typically arise in the petrous apex as a result of an inflammatory giant-cell reaction to cholesterol crystal deposits that are formed when normal aeration and drainage of temporal bone air cells become occluded resulting in transudation of blood into the petrous air cells. Surgical strategies include simple cyst decompression, radical excision of the cyst wall, or fenestration and drainage with silastic tubing. The authors present a giant cholesterol granuloma compressing the cerebellopontine angle and brainstem in a 35 year-old male who presented with progressive facial nerve weakness, sensorineural hearing loss, and vertigo. A combined transmastoid middle fossa extradural approach was performed to remove the cyst contents and decompress the brain-stem. A near total excision of the cyst wall was achieved with a small remnant adherent to the posterior fossa dura. Two separate silastic catheters were placed into the cyst cavity to provide “dual exhaust” drainage. One catheter drained the cyst cavity into the sphenoid sinus via a window made in the anteromedial triangle between V1 and V2. The second catheter drained the cyst cavity into the mastoidectomy cavity and middle ear. Postoperative MRI demonstrated regression of the cyst and excellent decompression of the brainstem. The patient experienced return of normal facial nerve function while hearing loss remained unchanged. He remained free of recurrence at 4 years postoperatively. The theoretical advantages of cyst wall removal combined with dual catheter drainage are longer term patency of cyst drainage and decrease of cyst recurrence. In this operative video atlas report, we describe the step-by-step technique and illustrate the operative nuances and surgical pearls to safely and efficiently perform the “dual exhaust” catheter drainage and resection of a giant cholesterol granuloma via a combined transmastoid middle fossa approach.The video can be found here: http://youtu.be/iZpYBP26ghA.

Download Full-text