Vestibular schwannomas (acoustic neuromas) develop due to mutations in Schwann cells that cause uncontrolled cell division. As a result, a tumor forms. As these tumors grow, they can compress the cochlear nerve causing unilateral hearing loss and tinnitus. Vestibular schwannomas may cause imbalance and occasionally vertigo. Intralabyrinthine schwannomas account for about 10% of vestibular schwannomas in centers that specialize in temporal bone imaging. Intracochlear schwannomas are the most common type of intralabyrinthine schwannomas. In this video, we describe an endoscopic transcanal transpromontorial approach to intracochlear schwannoma removal.
This surgery was performed by James Prueter, DO, of Southwest Ohio ENT Specialists in Dayton, OH.
Video editing was performed by Austin Miller, OMS-II, Ohio University Heritage College of Osteopathic Medicine.
This is a demonstration of the retrosigmoid approach for microsurgical resection of a cerebellopontine angle tumor. Th patient presented with gait disturbance and normal hearing. A suboccipital craniotomy was used for access to the cerebellopontine angle. Using microsurgical technique, the tumor was dissected away from the glossopharyngeal nerve. Pathological analysis confirmed that the tumor was a schwannoma of the glossopharyngeal nerve.
Chiari decompression is a common neurosurgical procedure. Chiari malformations present with a number of symptoms including Valsalva-induced headaches, swallowing dysfunction, and sleep apnea. Chiari malformations can also cause syringomyelia and syringobulbia. Surgical procedures used for the treatment of Chiari malformation include bone-only decompression (posterior fossa craniectomy +/- cervical laminectomy), craniectomy/laminectomy with duraplasty, and craniectomy/laminectomy/duraplasty with shrinkage or resection of the cerebellar tonsils. The procedure used depends on the specifics of the patient’s condition and the preference of the surgeon.
The patient presented here had undergone a prior Chiari decompression at the age of 20 months. This was bone-only with posterior fossa craniectomy and C1-2 laminectomy. The dura was not opened due to the presence of a venous lake. He initially had improvement in his symptoms. However, his headaches and snoring recurred, balance worsened, and dysphagia never improved. Therefore, a repeat Chiari decompression at the age of 28 months was performed as presented here.
Contributors: M. Nathan Nair and Timothy Deklotz
For patients with basilar invagination, an odontoidectomy may be necessary to decompress the brainstem, before further correction and stabilization of the craniocervical junction can be achieved. The open-mouth odontoidectomy procedure is associated with significant moribdity, and the endoscopic endonasal approach may be a better option. In this video, we provide a step-by-step demonstration of the endoscpic endonasal approach for odontoidectomy.
Contributors: Daniel Felbaum and H. Jeff Kim
The video demonstrates the resection of a trigeminal schwannoma via a middle fossa craniiotomy and anterior petrosectomy. A large dumbbell-shaped tumor was essentially two tumors in one. The anterior petrosectomy provided access mainly to the posterior component of the tumor, which was compressing the pons, and obscured by the tentorium and petrous ridge. Mobilization of the lateral wall of the cavernous sinus freed the anterior component and thus allowed the removal of the rest of the schwannoma.
Cranioplasty with barrel stave osteotomies to treat sagittal suture craniosynostosis.
Contributors: Ravi N. Samy, M.D., F.A.C.S (University of Cincinnati / CCHMC) and Shawn Stevens, M.D.
Cholesterol granuloma recurrence at the petrous apex. The patient had a prior surgery performed without stenting. Revision surgery at UC performed with double-barrel stent placement.
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Editor Recruited By: Ravi N. Samy, MD, FACS
Contributors: Micheala Lee
This is a demonstration of using the transventricular and subtemporal corridors for resecting a large middle fossa, tentorial meningioma. The video details the microsurgical technique for detaching the tumor from the tentorial incisura, working near critical structures such as the oculomotor nerve, trochlear nerve, and posterior communiating artery. It also includes precise demonstration of how to separate the massive tumor from the feeding arterial supply stemming from the posterior cerebral artery.
This video demonstrates a transcanal endoscopic infracochlear approach to the petrous apex in a patient with a large cholesterol granuloma. The patient presented with a history of profound left sensorineural hearing loss, hemifacial spasm, and House Brackmann Grade 2 facial function. Preoperative imaging demonstrated a T1 and T2 hyperintense heterogenous lesion in both petrous apices with the left being larger than the right on magentic resonance imaging. A computed tomography scan (CT) of the temporal bones demonstrates extension of the left petrous apex lesion into the internal auditory canal and cochlea.
Dr. Isaacson has had 2 patients who have had significant recovery of their bone line after using an infracochlear approach. In the unlikely event that the patient experiences hearing loss in the other ear, their cochlea is preserved for a possible CI. However, the patients hearing loss is likely secondary to the 8th nerve involvement of cholesterol granuloma erosion into IAC.
The patient in this surgical video has been monitored for a year. One year postop CT shows aeration of the apex. This patient’s facial spasm has resolved. Dr. Isaacson has used stents in the past, but in this case felt the opening was large enough that he could forego it. Patient did not recover their hearing.
Contributors: Jacob B. Hunter, Reid C. Thompson and David S. Haynes
Superior semicircular canal dehiscence (SCD) is a condition in which the bone overlying the superior semicircular canal is absent. The clinical presentation of SCD is highly variable and may include both auditory and vestibular manifestations. The more common symptoms include autophony, sound or pressure induced vertigo, hypersensitivity to sound, and low frequency conductive hearing loss. Repair can be accomplished via either transmastoid or middle fossa approaches, with numerous materials used to either plug or resurface the canal. Herein, we describe our resurfacing technique using a loose areolar tissue-bone pâté-loose areolar tissue sandwich through a middle fossa approach.