Combined Petrosal Approach for Resection of a Large Trigeminal Schwannoma With Meckel's Cave Involvement—Part I: Anatomic Rationale and Analysis: 2-Dimensional Operative Video

2020 ◽  
Author(s):  
Ali Tayebi Meybodi ◽  
James K Liu

Abstract Resection of large trigeminal schwannomas involving both posterior and middle cranial fossae is challenging. The depth of the surgical target in the superomedial corner of the cerebellopontine angle and the petrous apex makes for a difficult lesion to favorably access, expose, and safely resect. Judicious planning of a skull base approach is therefore the most crucial step in successful management of these formidable tumors. When properly chosen, planned, and executed, the combined petrosal approach sets the stage for an optimal exposure of such tumors that involve both posterior and middle cranial fossae. The present video is the first of a 2-part video presentation that explains the anatomic rationale of selecting a combined petrosal approach (anterior petrosectomy and retrolabyrinthine petrosectomy) for the resection of a large trigeminal schwannoma involving the posterior and middle cranial fossae with an extension into Meckel's cave in a 54-yr-old female presenting with 5-yr history of increasing headaches, left-sided face numbness, and disequilibrium. The benefits, risks, and alternatives of the surgical procedure were discussed in detail with the patient and she consented to proceed with surgery. Part I also discusses the important nuances of positioning the patient, as well as planning and execution of the skin incision, including pericranial flap harvesting.  Of note, the patient consented to the publication of images obtained from her.

2021 ◽  
Author(s):  
Kunal V Vakharia ◽  
Ryan M Naylor ◽  
Ashley M Nassiri ◽  
Colin L W Driscoll ◽  
Michael J Link

Abstract Epidermoid cysts are rare, benign lesions that result from inclusion of ectodermal elements during neural tube closure.1 Cysts are composed of desquamated epithelial cells and restrict diffusion on magnetic resonance imaging (MRI).2,3 Symptoms are attributable to anatomic location.4,5 In this video, we illustrate the surgical treatment of an epidermoid cyst located in the right cerebellopontine angle, petrous apex, and Meckel's cave. The patient, a 33-yr-old female with right-sided V1 trigeminal hypoesthesia, underwent surveillance imaging for 2 yr. However, she developed progressive V1 and V2 trigeminal hypoesthesia and imaging revealed enlargement of the lesion. Therefore, surgical resection was pursued. The patient consented to the procedure. The patient underwent a right middle fossa craniotomy and anterior petrosectomy. After identifying the greater superficial petrosal nerve and cutting the middle meningeal artery as it exited foramen spinosum, Kawase's triangle was drilled, and the dura over Meckel's cave and the subtemporal dura were opened. The lesion was resected, taking care to preserve the trigeminal nerve and the basilar artery. A retrosigmoid craniotomy was then fashioned. The cyst and its capsule were dissected off the brainstem and cranial nerves utilizing natural corridors between the trigeminal and vestibulocochlear nerves as well as between the facial and lower cranial nerves. Gross total resection was confirmed on postoperative MRI, and she was discharged home on postoperative day 5. Three months after surgery, she underwent formal pinprick testing, which revealed 95% loss of sensation in V1, 20% loss in V2, and normal sensation in V3. Three-month postoperative MRI showed no residual tumor.


2021 ◽  
Author(s):  
Yuanzhi Xu ◽  
Benjamin K Hendricks ◽  
Maximiliano Alberto Nunez ◽  
Ahmed Mohyeldin ◽  
Juan C Fernandez-Miranda ◽  
...  

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.


2018 ◽  
Vol 79 (S 05) ◽  
pp. S389-S390
Author(s):  
Maria Peris-Celda ◽  
Christopher Graffeo ◽  
Avital Perry ◽  
Lucas Carlstrom ◽  
Michael Link

Introduction Large and even moderate sized, extra-axial cerebellopontine angle (CPA) tumors may fill this restricted space and distort the regional anatomy. It may be difficult to determine even with high resolution magnetic resonance imaging (MRI) if the tumor is dural-based, or what the nerve of origin is if a schwannoma. While clinical history and exam are helpful, they are not unequivocal, particularly since many patients present with a myriad of symptoms, or conversely an incidental finding. We present an atypical appearing, asymptomatic CPA tumor, ultimately identified at surgery to be a trigeminal schwannoma. Case History A 40-year-old man presented with new-onset seizure. MRI identified an incidental heterogeneously contrast-enhancing CPA lesion (Fig. 1A–D). The tumor was centered on the internal auditory canal (IAC) with no tumor extension into Meckel's cave, IAC or jugular foramen. Audiometry demonstrated 10db of relative left-sided hearing loss with 100% word recognition. Physical examination was negative for focal neurologic deficits. A retrosigmoid craniotomy was performed and an extra-axial, yellow-hued mass was encountered and resected, which was ultimately confirmed to originate from the trigeminal nerve (Video 1). Gross total resection was achieved, and the patient recovered from surgery with partial ipsilateral trigeminal sensory loss and no other new neurologic deficits. Conclusion Pure CPA trigeminal schwannomas are rare, but should be considered in the differential for enhancing CPA lesions. Although, Meckel's cave involvement is frequently observed, it is not universal, and pure CPA schwannomas of all cranial nerves IV–XII have been reported in the literature.The link to the video can be found at: https://youtu.be/AlodYCu70F8.


2018 ◽  
Vol 16 (6) ◽  
pp. E172-E173
Author(s):  
Ken Matsushima ◽  
Michihiro Kohno ◽  
Nobuyuki Nakajima ◽  
Norio Ichimasu

Abstract The combined transpetrosal approach enables wide exposure around the petroclival region by cutting the tentorium and superior petrosal sinus. We often choose this approach for removal of tumors ventral to the facial and vestibulocochlear nerves, such as petroclival meningioma and epidermoid cyst, because complete removal of the tumor under direct visualization is required to prevent its later recurrence, especially in young patients. Recent reports revealed anatomical variations of the drainage of the superior petrosal sinus, and dural incision considering preservation of the superior petrosal vein was proposed.1-3 This 3-dimensional video shows a patient with an epidermoid cyst, which was surgically treated using the combined transpetrosal approach, with consideration of the variation of the superior petrosal sinus and preservation of the drainage route of the superior petrosal vein. The video was reproduced after informed consent of the patient. The patient is a 31-yr-old woman who presented with a left cerebellopontine angle epidermoid cyst extending into Meckel's cave. The superior petrosal sinus was of the lateral type, draining only laterally into the transverse–sigmoid junction without medial connection with the cavernous sinus.1 The combined transpetrosal approach was performed with cutting of the superior petrosal sinus medial to the entry point of the superior petrosal vein, in order to preserve its drainage into the transverse–sigmoid junction. Meckel’ cave was opened along its lateral margin, and tumor removal was accomplished, leaving only a minute part of the capsule strongly adhering to the neurovascular structures. The patient had no new permanent neurological deficits during follow-up. The figures in the video were modified from Matsushima et al1 by permission of the Congress of Neurological Surgeons.


2006 ◽  
Vol 59 (suppl_4) ◽  
pp. ONS-270-ONS-278 ◽  
Author(s):  
Samy Youssef ◽  
Eun-Young Kim ◽  
Khaled M.A. Aziz ◽  
Salah Hemida ◽  
Jeffrey T. Keller ◽  
...  

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.


2017 ◽  
Vol 14 (4) ◽  
pp. 432-440 ◽  
Author(s):  
Eleonora Marcati ◽  
Norberto Andaluz ◽  
Sebastien C Froelich ◽  
Lee A Zimmer ◽  
James L Leach ◽  
...  

Abstract BACKGROUND Although the term paraclival carotid pervades recent skull base literature, no clear consensus exists regarding boundaries or anatomical segments. OBJECTIVE To reconcile various internal carotid artery (ICA) nomenclatures for transcranial and endoscopic-endonasal perspectives, we reexamined the transition between lacerum (C3) and cavernous (C4) segments using a C1-C7 segments schema. In this cadaveric study, we obtained a 360°-circumferential view integrating histological, microsurgical, endoscopic, and neuroradiological analyses of this C3-C4 region and identified a distinct transitional segment. METHODS In 13 adult, silicone-injected, formalin-fixed cadaveric heads (26 sides), transcranial-extradural-subtemporal and endoscopic-endonasal CT­guided dissections were performed. A quadrilateral area was noted medial to Meckel's cave between cranial nerve VI, anterolateral and posterolateral borders of the lateral-paratrigeminal aspect of the precavernous ICA, and posterior longitudinal ligament. Endoscopically, a medial-paraclival aspect was defined. Anatomical correlations were made with histological and neuroradiological slides. RESULTS We identified a distinct precavernous C3-C4 transitional segment. In 18 (69%) specimens, venous channels were absent at the quadrilateral area, on the paratrigeminal border of the precavernous ICA. A trigeminal membrane, seen consistently on the superior border of V2, defined the lateral aspect of the cavernous sinus floor. The medial aspect of the precavernous ICA corresponded with the paraclival ICA. CONCLUSION Our study revealing the juncture of 2 complementary borders of the ICA, endoscopic endonasal (paraclival) and transcranial (paratrigeminal), reconciles various nomenclature. A precavernous segment may clarify controversies about the paraclival ICA and support the concept of a “safe door” for lesions involving Meckel's cave, cavernous sinus, and petrous apex.


2021 ◽  
Vol 14 (4) ◽  
pp. e242328
Author(s):  
Aastha Pruthi ◽  
Garjesh Rai ◽  
Ketan Mehra

The petrous apex is a pyramidal-shaped structure which is difficult to examine due to difficult anatomical location. Lesions in the petrous apex can be managed surgically or they can be incidental lesions, which are managed conservatively. Petrous apex cephaloceles (PAC) are the cystic lesion due to herniation in the Meckel’s cave of temporal bone. Bilateral PAC is a very rare phenomenon with only 21 cases reported in the literature so far. We present here a case of bilateral PAC, who presented with headache and was managed conservatively.


CSurgeries ◽  
2016 ◽  
Author(s):  
Walter Jean ◽  
Daniel Felbaum ◽  
H. Jeff Kim

2015 ◽  
Vol 7 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Yukitomo Ishi ◽  
Katsuyuki Asaoka ◽  
Taku Sugiyama ◽  
Yuka Yokoyama ◽  
Kazuyoshi Yamazaki ◽  
...  

Cerebellopontine angle tumors might occasionally provoke trigeminal neuralgia but are usually large enough to be diagnosed radiographically. We present a case of trigeminal neuralgia caused by a very small meningioma covering the suprameatal tubercle that displayed hyperostosis at the entrance of Meckel's cave and was not obvious on routine magnetic resonance (MR) images. A 72-year-old woman with intractable trigeminal neuralgia in the left V3 territory was referred to our institution. Preoperative imaging studies revealed that the left trigeminal nerve was medially distorted at the entrance of Meckel's cave by a laterally seated bone bulge covered by a minute enhanced lesion. Trigeminal nerve decompression surgery was performed via a retrosigmoid intradural suprameatal approach. We found a small meningioma that had compressed and flattened the trigeminal nerve root at the entrance of Meckel's cave, which was grossly and totally removed by suprameatal tubercle resection. There was no vascular compression of the trigeminal nerve root. The trigeminal neuralgia ceased completely after the operation. Accurate preoperative determination of the causative pathologies is essential to achieve adequate surgical results after microvascular decompression for neurovascular compression syndrome. Because conventional MR sequences are inadequate for the precise interpretation of complex neurovascular anatomy in the cerebellopontine angle and such small tumors can be overlooked on routine MR studies, high-resolution thin-slice MR examinations and careful radiological interpretations are required for correct diagnosis and treatment.


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