Certified Surgical First Assistant (CSFA) Practice Test

Which structures that travel through the temporal bone must be identified and preserved when performing a mastoidectomy?

1. stapes and incus

2. mastoid sinus and facial nerve

3. cochlea and vestibule

4. middle ear and eustachian tube

The correct answer is: mastoid sinus and facial nerve

The structures that must be identified and preserved during a mastoidectomy primarily include the mastoid sinus and the facial nerve. The mastoid sinus is a cavity within the temporal bone that plays a role in the drainage of the middle ear and is located near the mastoid process. Careful identification of the mastoid sinus is essential to prevent complications, as it can be affected by infection or disease processes that necessitate a mastoidectomy. The facial nerve is a critical component to consider, as it runs through the temporal bone and is responsible for controlling muscles of facial expression. Injury to the facial nerve can result in significant postoperative complications, including facial paralysis, which can severely affect patient quality of life. Therefore, both the mastoid sinus and facial nerve must be carefully preserved and navigated around during the procedure to reduce the risk of complications. While other structures related to hearing, such as the stapes and incus or components of the middle ear, are important in different contexts regarding ear surgeries, they are not situated in the same area as the mastoidectomy procedural focus, making them less critical to identify in this specific procedure. Similarly, the cochlea and vestibule play crucial roles in hearing and balance but are deeper within the ear's structure and