Endoscopic-assisted surgical repair of superior canal dehiscence using a keyhole middle fossa craniotomy approach Publication date: Available online 27 September 2019 Source: Operative Techniques in Otolaryngology-Head and Neck Surgery Author(s): Elliott D. Kozin, Daniel J. Lee Superior canal dehiscence (SCD) is a bony defect of the superior semicircular canal that is called SCD syndrome (SCDS) when associated with vestibular and auditory dysfunction. Surgical management of SCD is reserved for patients with intractable auditory and/or vestibular symptoms. As direct visualization of an arcuate eminence defect is most easily achieved from above, the majority of cases use a microscope-assisted middle fossa craniotomy. However, approximately 30% of SCD cases have a medial arcuate eminence defect along a downsloping tegmen. These defects can be difficult to visualize without a large cranial window, drilling down a prominent lateral skull base ridge, and/or prolonged brain retraction. In line with recent development of endoscopic ear surgery, the endoscope has been employed at our institution via a middle fossa craniotomy approach to repair a SCD. We believe that skull base endoscopy is a safe and effective way to identify and repair a medial or blue-lined SCD when used with a middle fossa craniotomy approach. The angled endoscope enhances visualization and transillumination of the SCD and reduces temporal lobe retraction. The following chapter highlights an endoscopic-assisted middle fossa craniotomy repair of SCD.

Transmastoid approach for surgical repair of superior canal dehiscence syndrome Publication date: Available online 24 September 2019 Source: Operative Techniques in Otolaryngology-Head and Neck Surgery Author(s): Raphaelle A. Chemtob, Samuel R. Barber, Angela W. Zhu, Elliott D. Kozin, Daniel J. Lee Patients with superior canal dehiscence syndrome may present with a myriad of auditory and/or vestibular complaints. Treatment of superior canal dehiscence syndrome depends on severity of symptoms and impact on quality of life. Surgery is recommended for patients with debilitating auditory and/or vestibular symptoms. The goal of surgery is to create a durable and watertight seal of the bony superior semicircular canal defect, thereby eliminating the “third window”. Repair involves either resurfacing and/or plugging of the dehiscent superior canal to eliminate the third window and reduce symptoms. Surgical options include middle fossa craniotomy or transmastoid (TM) approach. The main advantages of a TM approach includes (1) avoidance of a craniotomy, (2) lower risk of CSF leak, and (3) no brain retraction. The TM approach is ideal for superior petrosal sinus superior canal dehiscence cases as the defect is found medial along the skull base and can be isolated indirectly without direct manipulation of the brain and sinus. This chapter discusses the surgical technique of TM approach.

Posterior canal occlusion for benign paroxysmal positional vertigo Publication date: Available online 27 August 2019 Source: Operative Techniques in Otolaryngology-Head and Neck Surgery Author(s): Peng You, Ryan Instrum, Sumit K. Agrawal, Lorne S. Parnes Benign paroxysmal positional vertigo is the most common etiology of peripheral vertigo and is caused by the hydrodynamic influence from free-floating canaliths. Any of the 3 semicircular canals can be involved, but posterior canal BPPV is the predominant subtype. The condition is diagnosed clinically, and the preponderance of cases resolve spontaneously or are amenable to particle-repositioning maneuvers. A small subset of patients experience intractable symptoms for which surgical intervention can be considered. Transmastoid posterior canal occlusion surgery has been demonstrated to be a safe and curative procedure insofar as it can eradicate vertiginous symptoms while preserving auditory function.

Transcanal Cochleosacculotomy Publication date: Available online 22 August 2019 Source: Operative Techniques in Otolaryngology-Head and Neck Surgery Author(s): Yin Ren, Michael J. McKenna Meniere's disease (MD) is a clinical syndrome consisting of fluctuating hearing loss, episodic vertigo, and aural fullness related to endolymphatic hydrops. When MD is refractory to maximal medical management, surgical therapies can be highly effective. Operations for MD are classified into 2 types: one that ablates the vestibular system such as labyrinthectomy and the other relieves the pressure in the endolymphatic system by fistulization of the labyrinth and decompression of the endolymphatic sac. Transcanal cochleosacculotomy is an internal shunt procedure aimed to drain excessive endolymph. This article reviews the disease pathophysiology, as well as the history, indications, technical aspects, and outcomes associated with the operation. In sum, cochleosacculotomy is moderately successful in relieving vertigo symptoms with low overall morbidity and can serve as a useful alternative to other surgical modalities in carefully selected patients.

Vestibular nerve section via retrolabyrinthine craniotomy Publication date: Available online 20 August 2019 Source: Operative Techniques in Otolaryngology-Head and Neck Surgery Author(s): Zachary R. Barnard, Gregory P. Lekovic, Eric P. Wilkinson, Kevin A. Peng Meniere's disease can cause debilitating dizziness and vertigo despite maximal medical management. In select patients, treatment with vestibular nerve section provides optimal outcomes for symptom control and hearing preservation. Vestibular nerve section is also indicated in other vestibular disorders, including refractory uncompensated vestibular neuritis. Surgical approaches for vestibular nerve section include the retrolabyrinthine, retrosigmoid, middle fossa, and translabyrinthine craniotomies. The advantages of the retrolabyrinthine approach include rapid access, excellent visualization of the facial and cochlear nerves, and the possibility of hearing preservation in conjunction with consistent outcomes for vestibular symptoms. In this chapter, we discuss the retrolabyrinthine approach for vestibular nerve section, providing the reader with an overview of when, why, and how to employ the technique.

Intratympanic gentamicin injection for Meniere's disease Publication date: Available online 19 August 2019 Source: Operative Techniques in Otolaryngology-Head and Neck Surgery Author(s): Jenny X. Chen, Zizi Yu, Steven D. Rauch Meniere's disease is characterized by idiopathic progressive fluctuating hearing loss, tinnitus, and episodic vertigo. Intratympanic gentamicin injection is the preferred therapeutic option for those who have failed conservative management including lifestyle modifications and oral medications. The procedure is simple and can be performed in the outpatient setting under local anesthesia with manageable recovery time. Patients may experience a disequilibrium sensation beginning approximately 3-5 days after injection, which peaks around 10-14 days after injection and fades over the course of several more weeks. The presence of this reaction is an indicator of treatment response. Intratympanic gentamicin injection achieves control of vertigo in 80%-90% of patients. Risks include prolonged imbalance from delayed vestibular compensation after treatment, as well as sensorineural hearing loss, both of which are generally preferable to disabling vertigo attacks.

Vestibular nerve section via retrosigmoid craniotomy Publication date: Available online 19 August 2019 Source: Operative Techniques in Otolaryngology-Head and Neck Surgery Author(s): Lorenz Epprecht, Alexander M. Huber Vestibular neurectomy for Meniere's disease is considered as a treatment option when conservative methods fail to control debilitating vestibular symptoms. Most common surgical approaches today consist of transtemporal supralabyrinthine (middle fossa), retrolabyrinthine and retrosigmoid craniotomies. The aim of this article is to describe the procedure of vestibular neurectomy via a retrosigmoid approach. This approach can be performed alone or in combination with a retrolabyrinthine approach and allows good exposure of the cranial nerves VII and VIII in the cerebellopontine angle.

Radiological assessment of the vestibular system Publication date: Available online 13 August 2019 Source: Operative Techniques in Otolaryngology-Head and Neck Surgery Author(s): Katherine L. Reinshagen, Hugh D. Curtin Imaging is useful for the diagnosis, preoperative planning, and postoperative management for a number of vestibular pathologies. Computed tomography (CT) and magnetic resonance imaging (MRI) are the most commonly used modalities to assess the temporal bone. This review will discuss commonly used imaging techniques, review relevant anatomy on CT and MRI, and highlight examples of common vestibular pathologies on imaging.

Perioperative vestibular assessment and testing Publication date: Available online 12 August 2019 Source: Operative Techniques in Otolaryngology-Head and Neck Surgery Author(s): Jacob R. Brodsky, Guangwei Zhou Vestibular disorders can be difficult to accurately diagnose and manage. A careful history and focused physical examination are typically adequate to establish a diagnosis and initiate medical treatment. Vestibular testing is an important component of the work-up, but it is particularly essential for patients being considered for surgical intervention for a vestibular disorder, where the testing can be used to more definitively confirm a suspected diagnosis and to determine baseline vestibular organ function. In this article, we will first briefly review key components of the history and physical examination of patients with vestibular complaints. We will then discuss the most commonly used vestibular tests and their role in the preoperative assessment of patients undergoing vestibular surgery, including nystagmography, caloric testing, rotary chair testing, video head impulse testing, and vestibular evoked myogenic potential testing.