The Cerebellopontine Angle and Posterior Fossa Cranial Nerves by the Retrosigmoid Approach

Neurosurgery ◽  
2000 ◽  
Vol 47 (suppl_3) ◽  
pp. S93-S129 ◽  
Author(s):  
Albert L. Rhoton
Keyword(s):  
Posterior Fossa ◽  
Cerebellopontine Angle ◽  
Cranial Nerves ◽  
Retrosigmoid Approach

scholarly journals Microvascular Decompression for Geniculate Neuralgia through a Retrosigmoid Approach

2018 ◽  
Vol 80 (S 03) ◽  
pp. S322-S322
Author(s):  
Vincent N. Nguyen ◽  
Jaafar Basma ◽  
Jeffrey Sorenson ◽  
L. Madison Michael
Keyword(s):  
Microvascular Decompression ◽  
Cerebellopontine Angle ◽  
Cranial Nerves ◽  
Senior Author ◽  
Retrosigmoid Approach ◽  
Microsurgical Anatomy ◽  
Pain Syndromes ◽  
Large Vein ◽  
Microsurgical Techniques ◽  
Nervus Intermedius

Objectives To describe a retrosigmoid approach for the microvascular sectioning of the nervus intermedius and decompression of the 5th and 9th cranial nerves, with emphasis on microsurgical anatomy and technique. Design A retrosigmoid craniectomy is performed in the lateral decubitus position. The dura is opened and cerebrospinal fluid (CSF) is released from the cisterna magna and cerebellopontine cistern. Dynamic retraction without rigid retractors is performed. Subarachnoid dissection of the cerebellopontine angle exposes the 7th to 8th nerve complex. A neuromonitoring probe is used with careful inspection of the microsurgical anatomy to identify the facial nerve and the nervus intermedius as they enter the internal auditory meatus. The nervus intermedius is severed. A large vein coursing superiorly across cranial 9th nerve was coagulated and cut. A Teflon pledget is inserted between a small vessel and the 5th nerve. Photographs of the region are borrowed from Dr. Rhoton's laboratory to illustrate the microsurgical anatomy. Participants The senior author performed the surgery. The video was edited by Drs. V.N. and J.B. Outcome Measures Outcome was assessed by postoperative neurological function. Results The nervus intermedius was successfully cut and the 5th and 9th nerves were decompressed. The patient's pain resolved after surgery and at later follow-up. Conclusions Understanding the microsurgical anatomy of the cerebellopontine angle is necessary to identify the cranial nerves involved in facial pain syndromes. Subarachnoid dissection and meticulous microsurgical techniques are key elements for a successful microvascular decompression.The link to the video can be found at: https://youtu.be/pV5Wip7WusE.

scholarly journals Endoscopic Resection of a Cerebellopontine Angle Meningioma via a Retrosigmoid Approach

2019 ◽  
Vol 80 (S 03) ◽  
pp. S310-S310
Author(s):  
Frederick Luke Hitti ◽  
John Y.K. Lee
Keyword(s):  
Cerebellopontine Angle ◽  
Brain Mri ◽  
Cranial Nerves ◽  
Vascular Supply ◽  
Retrosigmoid Approach ◽  
Tumor Capsule ◽  
Imaging Characteristics ◽  
Adjacent Structures ◽  
Patient Reported ◽  
The Right

A variety of lesions may arise within the cerebellopontine angle (CPA). Schwannomas and meningiomas are most commonly found in this location. Imaging characteristics of meningiomas include hyperdensity on head computed tomography (CT) and avid contrast enhancement on T1-weighted postcontrast magnetic resonance imaging (MRI). Here, we present the case of a 49-year-old woman with enlarging right CPA meningioma. The patient reported mild hearing loss on the right but her neurological exam was otherwise benign. Since the lesion was enlarging and symptomatic, the patient was offered resection of the mass for diagnosis and treatment via an endoscopic retrosigmoid approach. We provide a video that illustrates the steps taken to resect this mass endoscopically. After cerebrospinal fluid (CSF) was drained to achieve brain relaxation, the tumor was visualized. The tumor had a rich vascular supply and had the appearance of a typical meningioma. The bipolar was used to cauterize the tumor's vascular supply. The tumor capsule was then opened with the microscissors. The round knife, suction, and ultrasonic tissue debrider were used to debulk the tumor. After internal debulking of the tumor, the capsule was dissected off the cerebellum and mobilized. A combination of blunt and sharp dissection was done to free the tumor capsule from the adjacent structures. Inferiorly, the lower cranial nerves were visualized. Tissue pathology confirmed a diagnosis of grade I meningioma. A gross total resection was achieved and the patient remained neurologically stable, postoperatively. Furthermore, T1-weighted postcontrast brain MRI, 1 year after surgery, showed no residual.The link to the video can be found at: https://youtu.be/X9c_inLp-So.

scholarly journals Extended Retrosigmoid Approach for the Resection of a Pontomedullary Junction Cavernous Malformation

2018 ◽  
Vol 79 (S 05) ◽  
pp. S418-S419
Author(s):  
Jaafar Basma ◽  
Vincent Nguyen ◽  
Jeffrey Sorenson ◽  
L. Michael
Keyword(s):  
Cerebellopontine Angle ◽  
Cavernous Malformation ◽  
Cranial Nerves ◽  
Extent Of Resection ◽  
Senior Author ◽  
Retrosigmoid Approach ◽  
Microsurgical Anatomy ◽  
Brainstem Cavernoma ◽  
Lateral Decubitus ◽  
Pontomedullary Junction

Objectives To describe an extended retrosigmoid approach for the resection of a cavernoma involving the ponto-medullary junction, with emphasis on the microsurgical anatomy and technique. Design A retrosigmoid craniotomy is performed in the lateral decubitus position and the sigmoid sinus exposed. After opening the dura, sutures are placed medial to the sinus to allow its gentle mobilization. Cerebrospinal fluid (CSF) is drained from the cisterna magna, and cerebellopontine cistern, and dynamic retraction is used over the cerebellum. Subarachnoid dissection of the cerebellopontine angle gives access to cranial nerves IX/X, VII/VIII, and VI. Inspection of the pontomedullary junction medial to the facial nerve reveals hemosiderin staining in that region. A small pial opening is made, exposing the hemorrhagic cavity. The cavernous malformation is then identified, dissected circumferentially, and resected. Photographs of the region are borrowed from Dr Rhoton's laboratory to illustrate the microsurgical anatomy. Participants The senior author performed the surgery. The video was edited by Drs. J.B. and V.N. Outcome Measures Outcome was assessed with extent of resection and postoperative neurological function. Results A gross total resection of the lesion was achieved. The patient did not develop any postoperative deficits. Conclusion Understanding the microsurgical anatomy of the cerebellopontine angle and meticulous microneurosurgical technique are necessary to achieve a complete resection of a brainstem cavernoma. The extended retrosigmoid approach provides an adequate corridor to the pontomedullary junction.The link to the video can be found at: https://youtu.be/FIKixWJT75w.

Rare Tumors of the Cerebellopontine Angle

1980 ◽  
Vol 88 (5) ◽  
pp. 555-559 ◽  
Author(s):  
Derald E. Brackmann ◽  
Loren J. Bartels
Keyword(s):  
Posterior Fossa ◽  
Cerebellopontine Angle ◽  
Malignant Tumors ◽  
Rapid Development ◽  
Cranial Nerves ◽  
Benign Tumors ◽  
Rare Tumors ◽  
Cerebellopontine Angle Tumors ◽  
Acoustic Neurinomas ◽  
The Subject

In a series of 1,354 cerebellopontine angle tumors treated at the Otologic Medical Croup, approximately 10% were lesions other than acoustic neurinomas. Of the non-acoustic tumors, the majority were meningiomas, primary cholesteatomas, and neurinomas of other cranial nerves in the posterior fossa. Twenty-five other lesions were encountered; these rare tumors are the subject of this study. The benign tumors resemble acoustic neurinomas in appearance and in the method of treatment. Malignant tumors are characterized by rapid development of symptoms and are difficult to treat because of invasion of vital structures in the area.

scholarly journals Endoscopic Assisted Retrosigmoid Approach for Cerebellopontine Angle Epidermoid Tumor

2018 ◽  
Vol 79 (S 05) ◽  
pp. S413-S414
Author(s):  
Katherine Kunigelis ◽  
Alexander Yang ◽  
A. Youssef
Keyword(s):  
Cerebellopontine Angle ◽  
Antiviral Agents ◽  
Cranial Nerves ◽  
Pineal Region ◽  
Retrosigmoid Approach ◽  
Gross Total Resection ◽  
Total Resection ◽  
Auditory Evoked Responses ◽  
The Right ◽  
Surgical Corridor

This case is a 20-year-old male, who presented with 1 month of right facial weakness (HB4) and complaints of ipsilateral eye dryness. He was initially treated for Bell's palsy with steroids and antiviral agents, but subsequently developed diplopia with right lateral gaze and underwent an MRI (magnetic resonance imaging). MRI demonstrated a 4.5 cm irregular lesion in the right cerebellopontine angle consistent with an epidermoid cyst. Because the tumor had grown with the development of the central nervous system, it has extended into different compartments, including the tentorial incisura and pineal region. A predefined surgical corridor created by the tumor facilitated access to the majority of the tumor through a retrosigmoid approach. Angled endoscopes (30-degree up and down) provided further visualization of tumor away from the line of sight of the microscope, thus allowing for gross total resection of the lesion. This video also demonstrates a sharp dissection technique necessary for safe removal of adherent tumor from critical neurovascular structures, including the basilar artery and several cranial nerves. The ipsilateral auditory evoked responses (ABRs) showed slight improvement from baseline toward the end of the case. A gross total resection was achieved, as shown by the MRI. The patient remained at his baseline cranial nerve (CN) V, VII, and VIII deficits during the immediate postoperative period.The link to the video can be found at: https://youtu.be/vCq5juJh8hk.

scholarly journals Resection of Cerebellopontine Angle Meningioma via Retrosigmoid Approach Aiming for Hearing Improvement

2019 ◽  
Vol 80 (S 03) ◽  
pp. S302-S303
Author(s):  
Yuki Shinya ◽  
Hideaki Ono ◽  
Tomohiro Inoue ◽  
Akira Tamura
Keyword(s):  
Cerebellopontine Angle ◽  
Cranial Nerves ◽  
Auditory Brainstem ◽  
Retrosigmoid Approach ◽  
Maximum Diameter ◽  
Hearing Improvement ◽  
Female Case ◽  
Brainstem Response ◽  
The Brain ◽  
Preoperative Examination

We present a 71-year-old female case of left cerebellopontine angle (CPA) meningioma who presented with progressive hearing loss. The tumor was 35 mm in maximum diameter, obviously compressed the brain stem and cerebellum, and also displaced cranial nerves 7th and 8th anteriorly (Fig. 1). Retrosigmoid approach was chosen to resect the tumor aiming for hearing improvement. We performed dissection of the tumor from cranial nerves 7th and 8th gently and resection of the tumor except for the part adhesive to these cranial nerves (Fig. 2). Postoperative course was good without any new neurological deficit. Postoperative examination also showed improvement of high-frequency hearing of the left side, and auditory brainstem response demonstrated wave 2 to 5, which was not identify on preoperative examination. These procedures enabled safe and effective resection of the tumor and contributed to hearing improvement.The link to the video can be found at: https://youtu.be/hkRSCxtV3bY.

scholarly journals Endoscope-Assisted Retrosigmoid Approach for Cerebellopontine Angle Epidermoid Tumor

2018 ◽  
Vol 79 (S 05) ◽  
pp. S409-S410
Author(s):  
Francisco Vaz-Guimaraes ◽  
Paul Gardner ◽  
Juan Fernandez-Miranda
Keyword(s):  
Surgical Resection ◽  
Cerebellopontine Angle ◽  
Clinical Symptoms ◽  
Tumor Resection ◽  
Cranial Nerves ◽  
Complete Resection ◽  
Retrosigmoid Approach ◽  
Incomplete Resection ◽  
Endoscopic Techniques ◽  
Epidermoid Tumor

Objectives Surgical resection is the only effective treatment modality for epidermoid tumors. Complete resection with preservation of neurological function must be pursued whenever possible, because it offers a cure for patients. However, the inability to identify hidden remnants, interdigitating around cranial nerves, especially in larger tumors, may be a contributing factor for incomplete resection. This operative video demonstrates the technical nuances in achieving complete resection of a cerebellopontine angle epidermoid tumor via an endoscope-assisted retrosigmoid approach. Design and Setting Operative video of an endoscope-assisted retrosigmoid, approach for complete resection of a cerebellopontine angle epidermoid tumor. The patient was a 16-year-old female, who presented with 1-year history of worsening headaches and imbalance. Her neurological exam was normal, including normal cranial nerve function, and hearing. Radiological evaluation revealed an epidermoid tumor in the right cerebellopontine angle, extending to the interpeduncular cistern. Surgical resection was recommended. Given extension of the tumor across the midline, an endoscope-assisted procedure was planned to increase the odds of complete resection. Results The video demonstrates the surgical technique applied for tumor resection. The patient's clinical symptoms resolved completely after surgery and she remained neurologically intact. Postoperative magnetic resonance imaging (MRI) confirmed complete tumor resection. There were no postoperative complications. Conclusions The use of endoscopic techniques for resection of cerebellopontine angle epidermoid tumor is safe and effective and may increase the odds of complete resection, especially in larger tumors spreading across the midline, by enabling the surgeon clear visualization of deep-seated and contralateral relevant neurovascular structures, not readily accessible by the surgical microscope.The link to the video can be found at: https://youtu.be/X6YP_7OeQQE.

A stepwise illustration of the retrosigmoid approach for resection of a cerebellopontine meningioma

2014 ◽  
Vol 36 (v1supplement) ◽  
pp. 1 ◽  
Author(s):  
Ulaş Cıkla ◽  
Gregory C. Kujoth ◽  
Mustafa K. Başkaya
Keyword(s):  
Cranial Nerve ◽  
Cerebellopontine Angle ◽  
Cranial Nerves ◽  
Retrosigmoid Approach ◽  
Vascular Lesions ◽  
Link Type ◽  
Vertebrobasilar System ◽  
Acoustic Neuromas ◽  
Vascular Decompression

The retrosigmoid approach is a work-horse approach to the cerebellopontine angle (CPA), providing access from the foremen magnum to the tentorium. Indications for this approach are variable such as resection of meningiomas, acoustic neuromas and epidermoid tumors, treatment of vascular lesions of vertebrobasilar system, vascular decompression of cranial nerves (V, VII, IX, X), cranial nerve neurectomies, and intrinsic lesions of the cerebellum and brainstem. In this video, we demonstrate the use of retrosigmoid craniotomy for resection of a large CPA meningioma, delineating all steps including positioning, mapping.The video can be found here: http://youtu.be/kISkYS16Brk.

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