Middle Ear and Mastoid Surgery (eBook)

Chapter 1

AN OVERVIEW OF MIDDLE EAR AND MASTOID SURGERY

Rex S. Haberman II

There are many indications for middle ear and mastoid surgery. Traumatic and nontraumatic perforations of the eardrum need repair, accomplished through a variety of ways. For a small defect, a myringoplasty or repair of the eardrum without lifting a tympanomeatal flap might suffice; for larger perforations, tympanoplasty becomes necessary. Techniques of tympanoplasty vary according to the size of the perforation and underlying disease. A transcanal approach may be all that is required, but frequently that does not give the surgeon sufficient exposure, so a postauricular approach becomes necessary. Medial and lateral grafting techniques all have their place, depending on the nature of the primary problem and training and preference of the surgeon. Both techniques have excellent results, as the take rate exceeds 90%.

Chronic otitis media with and without cholesteatoma is the major disease that leads the otologic surgeon to perform a mastoid operation. There are different approaches to mastoid surgery. Many believe that the logical approach to mastoidectomy is to leave the posterior ear canal intact and perform a canal-wall-up mastoidectomy. Others believe that leaving the posterior ear canal intact leaves the patient with too high a risk for recurrence of disease and that it is necessary to take the posterior canal wall down or perform a canal-wall-down mastoidectomy. There are modifications of those two basic mastoid surgeries, such as leaving the incus bridge intact, limiting the amount of bone removed, or even bypassing the mastoid completely if the disease is limited to the epitympanum.

In the middle ear, an assortment of conditions exist that call for surgical intervention. Erosion of the incus is a familiar condition that the ear surgeon encounters. There are many ossiculoplasty techniques that address that problem, including the insertion of various prostheses. Other ossicles may be involved in disease, either destroyed or fixed by fibrous tissue or tympanosclerosis, at times requiring complete replacement of the ossicular chain. Since the advent of stapedectomy almost 50 years ago, refinement of that technique has led to predictable and excellent results. There are many prostheses available to the general market, and most have led to the expected good result. Some new innovative prostheses are on the horizon, based on novel ideas regarding connection between the inner ear vestibule and incus.

Surgical treatment for Meniere's disease and other vertiginous conditions, such as benign paroxysmal positional vertigo, typically involves performing mastoidectomy. At a minimum, simple mastoidectomy provides the basic entry to the labyrinth and endolymphatic sac. A thorough knowledge of the mastoid becomes a prerequisite for performing more complex temporal bone operations. From the mastoid, entry into the membranous labyrinth and internal auditory canal is possible, as is exposure of the posterior fossa dura, endolymphatic sac, and retrolabyrinthine area. Control of vertigo is the primary reason to perform inner ear surgery, although other symptoms such as hearing loss or tinnitus are often affected.

In the last few years, implantable hearing aids appeared, and implanting them may be a commonly performed procedure in the future. The technology continues to be refined, and as a result there is high expectation. Cochlear implants are relatively commonplace today. They have helped many patients who previously may have required sign language or lip reading. In the future, we can expect changes that could fulfill the desired objectives of otologists and otolaryngologists, that is, serving the needs of the hearing impaired to the greatest degree.

This book provides general otolaryngologists and residents of otolaryngology with a comprehensive presentation of the current status of middle ear and mastoid surgery. A chapter is assigned to each procedure, allowing easy reference to a specific operation in which the otolaryngologist may be interested. Each chapter describes in detail patient preparation and surgical technique. There is less focus placed on disease depiction, as other texts already provide that. After reviewing a chapter, the physician may then proceed to perform the selected surgery with added confidence and understanding of appropriate elements of the procedure.

PATIENT SELECTION AND INFORMED CONSENT

Virtually all patients who require middle ear or mastoid surgery have endured chronic symptoms. Patients with cholesteatoma typically present with purulent otorrhea that has plagued them for years. Otosclerotic patients often complain that their hearing has diminished gradually over many years. It is not uncommon for Meniere's disease patients to have received treatment by a primary care physician for a long period before finally seeing the specialist, enduring many episodes of vertigo that may even have elicited trips to the emergency room. Thus, by the time the otolaryngologist sees the patients, expectations are high to find a cure and improve their lifestyle. Patients may exhibit unrealistic expectations about their condition and believe that a quick turnaround is imminent once treated by the otolaryngologist.

The initial consultation is usually a time to become familiar with the patient's condition. This consultation may not be the appropriate time to schedule surgery. Instead, a second appointment becomes the logical time to present surgical options, especially if diagnostic tests such as computed tomography (CT) need to be done before contemplating an operation.

A second, third, and fourth appointment, as necessary, allow for the development of rapport and trust, which are required if the surgeon is to perform complicated otologic procedures. There are times, however, when a patient arrives at the appointment, audiograms and CT scans in hand, ready to be scheduled. Those patients, typically referred from an otolaryngologist to an otologist, can be scheduled for surgery, as the patient and the referring otolaryngologist expect as much and may be dissatisfied if those needs are not met.

It is important to present a reasonable prognosis based on a variety of information. First, otolaryngologists must review their own results and make determinations of outcome based on that data. In addition, presentation of results published in the current literature informs the patient about regional and national outcomes. If an insufficient number of cases exist to make reasonable predictions, reliance on published data is acceptable as long as this is clearly explained to the patient. Intraoperative and postoperative risks and complications must be presented to the patient, including risks of hearing loss, both sensorineural and conductive, vertigo, altered taste, and facial nerve injury, both temporary and permanent. Other complications and postoperative expectations should also be explained depending on the type of surgery performed. A consent form, specific to a particular doctor or office, may be utilized, but that form would not replace the hospital or surgery center's document. It would only serve to document within the practitioner's own medical record that informed consent has been obtained. In addition to discussing risks and complications of the operation, the surgeon must also present risks and complications of refusal to comply with the recommended treatment. If a mastoidectomy is indicated but the patient refuses to have the procedure, he must be told about the suppurative complications of chronic otitis media such as meningitis and temporal lobe abscess. The point is not to overwhelm the patient. Instead, care must be taken to educate patients about the serious and complex nature of their disease. Important decisions require information; if maximal information is available, a better choice is made.

SCHEDULING AND PERIOPERATIVE MANAGEMENT

After the patient agrees to comply with recommendations of surgery, the operation is scheduled. It is important to schedule an appropriate amount of time for the otologic procedure, including adequate turnover. That will depend on many factors, such as determination of facility, experience of the support staff, anesthesia, and proficiency of the surgeon. A canal-wall-up tympanomastoidectomy with complete exposure and opening of the facial recess will require at least 2 hours for an expert team, including operating room turnover; the same procedure may require 3½ hours for a less experienced crew. Ample time is a prerequisite for a successful outcome. Earnest consideration should be given to schedule these surgeries on days when no other obligation is needed, especially if a full-day block is available. Otherwise, a cushion of extra time will allow for unsuspected findings that may prolong the operation. As an example of a perilous scenario, a surgeon finds he will be late for office hours because he is operating near a dehiscent facial nerve that is covered by cholesteatoma. Rather than facing that situation, allocate more time than expected.

The otologic surgeon must take a multifaceted approach to preparing the patient and the operating room for commencement of the surgery. After anesthesia induction, the surgeon should be in the operating room, making sure the microscope assembly and organization are correct and that the patient's position is appropriate. That effort, not left to the operating room staff, is the responsibility of the operating surgeon. Ultimately, the surgeon is accountable for making sure that the instrumentation is as it should be and the otologic drill is suitable. A case scheduled at a facility that is new or infrequently attended requires that the surgeon coordinate his...