Cochlear Implantation for Common Cavity Deformity

The common cavity deformity (CCD) of the inner ear is a condition that requires cochlear implantation (CI), but complications such as facial nerve injury, penetration of the electrode array into the internal auditory canal (IAC), and electrode displacement are common. This book describes the embryology, preoperative auditory, balance and vestibular evaluation, electrophysiology and radiology aspects, surgical technique, and CI outcomes of CCD. It also reviews the balance and vestibular function research of CCD patients before and after surgery.

Format: Paperback / softback
Length: 130 pages
Publication date: 05 January 2023
Publisher: Springer Verlag, Singapore

The common cavity deformity (CCD) of the inner ear is a condition characterized by the fusion of the cochlea and vestibule, forming a single cavity. This deformity is often associated with cochlear implantation (CI), which is a surgical procedure used to treat hearing loss in individuals with severe to profound deafness. CCD affects approximately 15% to 25% of inner ear malformations. While CI can provide significant benefits to patients, it is not without its complications. These complications include facial nerve injury, penetration of the electrode array into the internal auditory canal (IAC), and electrode displacement. These issues can lead to unsatisfactory outcomes and may require additional surgeries or interventions.

This book aims to provide a comprehensive overview of CCD, encompassing its embryology, preoperative auditory, balance, and vestibular evaluation, electrophysiology, and radiology aspects. It also delves into the surgical technique and CI outcomes, with a focus on electrode array design. Additionally, the book reviews the balance and vestibular function research of CCD patients before and after surgery, offering valuable insights for otologists and practitioners in related fields.

The embryology of CCD is an important aspect to understand, as it helps in predicting the surgical outcomes and planning the treatment approach. The cochlea and vestibule develop from different embryonic structures, and their fusion can occur at different stages of development. The presence of CCD can affect the structure and function of the inner ear, leading to hearing loss and balance disorders.

Preoperative auditory, balance, and vestibular evaluation is crucial in assessing the candidacy of patients for CI and determining the appropriate surgical approach. This evaluation includes hearing tests, vestibular tests, and imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI). These tests help in identifying the extent of the CCD and the underlying causes of hearing loss.

Electrophysiology and radiology are essential tools in diagnosing and treating CCD. Electrophysiological tests, such as auditory brainstem responses (ABR) and electrocochleography (ECoG), help in mapping the auditory pathways and determining the location of the cochlear nucleus. Radiology studies, such as CT or MRI, provide detailed images of the inner ear and can help in identifying the extent of the CCD and any associated abnormalities.

The surgical technique for CCD varies depending on the underlying anatomy and the severity of the deformity. The most common surgical approach is the middle ear approach, which involves making an incision in the middle ear and accessing the inner ear through the mastoid bone. Other surgical approaches, such as the retrosigmoid approach or the transoral approach, may be used in certain cases.

The surgical outcomes of CCD depend on various factors, including the surgical technique, the underlying anatomy, and the patient's overall health. Complications such as facial nerve injury, penetration of the electrode array into the IAC, and electrode displacement are common, but they can be managed effectively with appropriate surgical techniques and post-operative care.

Electrode array design is a critical aspect of CCD surgery, as it determines the efficacy of the CI device. The electrode array should be designed to provide optimal sound localization and speech understanding in the affected ear. The number and placement of the electrodes can vary depending on the patient's anatomy and hearing requirements.

In conclusion, CCD is a common cavity deformity of the inner ear that is often associated with cochlear implantation. While CI can provide significant benefits to patients with hearing loss, it is not without its complications. This book provides a comprehensive overview of CCD, encompassing its embryology, preoperative evaluation, surgical technique, electrode array design, and balance and vestibular function research. It serves as a valuable reference for otologists and practitioners in related fields, helping them better understand and manage CCD patients.

Weight: 232g
Dimension: 235 x 155 (mm)
ISBN-13: 9789811682193
Edition number: 1st ed. 2022