Head & Neck Surgery - Otolaryngology
4th Edition

140
Cholesteatoma
Ted A. Meyer
Chester L. Strunk Jr.
Paul R. Lambert
Cholesteatomas are cystlike, expansile lesions of the temporal bone lined by stratified squamous epithelium that contain desquamated keratin. They most frequently involve the middle ear and mastoid, but they may develop anywhere within the pneumatized portions of the temporal bone. They may be congenital (infrequently) or acquired.
The accumulation of keratin may cause infection, otorrhea, bone destruction, hearing loss, facial nerve paralysis, a labyrinthine fistula, and intracranial complications such as epidural and subdural abscesses, parenchymal brain abscesses, meningitis, and thrombophlebitis of the dural venous sinuses.
Cholesteatoma is a misnomer originally coined by Johannes Mueller in 1838 when he described “layered pearly tumor of fat, which was distinguished from other fat tumors by the biliary fat or cholesterin that is interspersed among the sheets of polyhedral cells” (1). Cholesteatomas do not contain fat, and they do not usually contain cholesterin. Nevertheless, the term remains, despite a more appropriate term suggested by Schuknecht: keratoma.
The matrix of a cholesteatoma is composed of fully differentiated squamous epithelium resting on connective tissue. The deeper layers of the epithelium of a cholesteatoma matrix show activity in the form of downgrowths into the underlying connective tissue. There is always a layer of granulation tissue in contact with bone. This layer of granulation tissue elaborates various enzymes such as collagenase resulting in bone destruction.
Congenital Cholesteatoma
Congenital cholesteatoma is defined by Derlacki and Clemis (2) as an embryonic rest of epithelial tissue in the ear without tympanic membrane perforation and without a history of ear infection. Levenson et al. (3,4) have modified the definition of a congenital cholesteatoma toinclude a normal pars flaccida and pars tensa, no history of prior otorrhea, and no history of prior otologic procedures. Prior episodes of otitis media without otorrhea are not criteria for excluding congenital origin. Two thirds of the middle ear congenital cholesteatomas are seen as a white mass in the anterior-superior quadrant (Fig. 140.1). They may also be found within the tympanic membrane and in the petrous apex. The mean age at presentation for a congenital middle ear cholesteatoma is 4.5 years, with a male to female preponderance of 3:1 (4).
The pathogenesis of congenital cholesteatomas is incompletely understood. In a review of the development of the epibranchial organs, Teed (5) noted an ectodermal epithelial thickening that developed in proximity of the geniculate ganglion, medial to the neck of the malleus. This mass of epithelial cells soon undergoes involution to become mature middle ear lining. Teed believed that if involution failed to take place, this formation could be the source of a congenital cholesteatoma. In pursuit of this theory, Michaels (6,7) undertook a review of fetal human temporal bones and identified a squamous cell tuft present from 10 to 33 weeks of gestation in 37 of 68 specimens studied. He termed this structure the epidermoid formation and noted it to be located in the anterosuperior wall of the developing middle ear cleft. Failure of the epidermoid formation to involute could be the basis for the development of cholesteatomas in the anterior mesotympanum (8,9,10). Other investigators implicate ectodermal migration or even metaplasia of the middle ear mucosa in the pathogenesis of congenital cholesteatomas (11,12).
Acquired Cholesteatoma
Acquired middle ear cholesteatomas come in two varieties: primary or retraction pocket cholesteatoma and secondary cholesteatoma. Cholesteatomas that arise from retraction
P.2082

pockets are known as primary acquired cholesteatomas on the basis that infection has not given rise to the cholesteatoma. Several theories have been advanced to explain the formation of primary acquired or attic retraction cholesteatomas, including invagination of the pars flaccida, basal cell hyperplasia, otitis media with effusion, and perforation of the pars flaccida membrane with epithelial ingrowth (Table 140.1). Patients with cleft palates are particularly prone to the development of primary acquired attic cholesteatomas (13,14,15,16,17).
Figure 140.1 Congenital cholesteatoma of the anterior-superior quadrant. AI, anterior inferior; AS, anterior superior; PI, posterior inferior; PS, posterior superior.
The invagination theory is supported by the observations of Aschoff in 1897 and Wittmaack in 1933 (18). They proposed that an infantile sterile otitis media neonatorum or nonbacterial otitis media develops soon after birth. Before it has had time to resorb, a permanent fibrosis and thickening of the embryonic subepithelial tympanic connective tissue occurs resulting in blockage of the attic causing a localized negative pressure with retraction of the pars flaccida. The fibrosis and thickening in the attic blocks the normal process of pneumatization of the epitympanum and antrum and decreases the pneumatization of the mastoid process and petrous portions of the temporal bone throughout the patient’s life. This small dimplelike retraction of the pars flaccida that cannot be reduced by inflation of the eustachian tube is the first stage in the development of an attic cholesteatoma.
TABLE 140.1 PATHOGENESIS OF CHOLESTEATOMAS
Primary acquired cholesteatomas
   Invagination theory
   Basal cell hyperplasia theory
   Otitis media with effusion theory
   Epithelial invasion theory
Secondary acquired cholesteatomas
   Implantation theory
   Metaplasia theory
   Epithelial invasion theory
A second method by which a small retraction pocket may develop is from longstanding otitis media with effusion (Fig. 140.2). Bluestone and Klein (13) demonstrated that in children with attic retractions, the eustachian tube constricts rather than dilates with swallowing. This results in impaired ventilation of the middle ear and mastoid air cell system and fluctuating or sustained high negative middle ear pressures. Negative middle ear pressure caused by eustachian tube dysfunction can result in retraction of the pars flaccida and collection of desquamated debris.
Like primary acquired cholesteatomas, several pathogenic mechanisms may contribute to the formation of secondary acquired cholesteatomas (Table 140.1). The implantation theory, the metaplasia theory, and the epithelial invasion theory have all been advanced as possible mechanisms involved in cholesteatoma formation. The implantation theory describes the formation of a cholesteatoma by the iatrogenic implantation of skin into the middle ear or eardrum as a result of surgery, a foreign body, or a blast injury. Cholesteatomas may develop secondary to a myringotomy for ventilating tube placement or a tympanoplasty procedure. They occur as a result of epithelial migration or displacement through the myringotomy or from the displacement of a flap of the tympanic membrane into the middle ear at the time of a tympanoplasty. Secondary acquired cholesteatomas are also thought to arise from a perforation as a result of acute necrotic otitis media in childhood (19).
The metaplasia theory describes the transformation of columnar epithelium to keratinized stratified squamous epithelium secondary to chronic or recurrent otitis media. Support for this theory comes from changes that occur in the bronchi in the face of chronic irritation and infection. However, metaplasia is not thought to be a significant cause of cholesteatoma in humans (20). The epithelial invasion theory involves the invasion of the middle ear by skin from the meatal wall of the outer drum surface through a marginal perforation or an attic perforation (21). This is supported by experimental evidence demonstrating that epithelial cells migrate along a surface until they encounter another epithelial surface, at which point they stop migrating; this is known as contact inhibition.
P.2083

If the middle ear mucosa were destroyed by infection, then this would allow for epithelial migration from a marginal perforation. This is the generally accepted theory for the formation of secondary acquired cholesteatomas of the posterior-superior tympanic membrane.
Figure 140.2 Evolution of an attic cholesteatoma.
A unique feature that cholesteatoma and tympanic membrane epithelium have in common is migration. No other epithelium tested, including skin, vocal cord, and oral epithelium, has shown the locomotion present with tympanic membrane epithelium and cholesteatoma (22). Once a retraction pocket develops, the epithelial migratory pattern is altered and keratin accumulates. This is the second stage in the development of a cholesteatoma. The sac slowly enlarges by accumulation of keratin and other debris until the walls of the attic are reached. Once this point is reached, bone resorption occurs. Three factors appear to be involved in the process of bony resorption: (a) mechanical, related to pressure generated by the expansion of cholesteatoma as it accumulates increasing amounts of keratin and purulent debris (23,24,25); (b) biochemical, due to bacterial elements (endotoxins), products of the host’s granulation tissue (collagenase, acid hydrolases), and substances related to the cholesteatoma itself (growth factors, cytokines) (26,27,28,29,30,31,32,33,34); and (c) cellular, predominantly induced by osteoclastic
P.2084

activity (35,36,37). It is likely that bone destruction in cholesteatoma results from a combination of these factors, but clarification is needed regarding their specific roles.
Figure 140.3 Infected cholesteatoma of the attic eroding the scutum (arrow).
Figure 140.4 Spaces and pouches on the middle ear defined by various ligaments and folds. 1, posterior mallear fold; 2, posterior tympanic stria; 3, lateral mallear fold; 4, anterior tympanic membrane stria; 5, malleus (short process); 6, tensor fold; 7, superior mallear fold; 8, superior incudal fold; 9, lateral incudal fold; 10, anterior epitympanic space; 11, anterior mallear ligament; 12, postincudal ligament; 13, Prussak’s space; 14, anterior pouch (VT); 15, posterior pouch of von Troeltsch.
Multinucleated osteoclasts within the subepithelial matrix of a cholesteatoma release acid phosphatase, collagenase, and other proteolytic enzymes that resorb the bone products. The osteoclasts may be further activated by infection, pressure, and Langerhans cells through an immune mechanism. Cholesteatoma debris is a favorite culture medium for bacteria from the external meatus, including staphylococci, Pseudomonas aeruginosa, Proteus, Enterobacter, aerobic and anaerobic nonhemolytic streptococci, diphtheroid bacilli, and Aspergillus molds. When the cholesteatoma becomes infected from water contamination, a foul-smelling discharge ensues. An active infected cholesteatoma will resorb bone at a faster rate.
The ability of cholesteatomas to erode bone is what makes them particularly dangerous (Fig. 140.3). Their expansion is dictated by space available, their migratory tendency, and their internal desquamation. Pressure alone may cause bone resorption to take place.
Surgical Anatomy
Cholesteatomas are channeled along characteristic pathways by ligaments and folds. During the third to fifth fetal months, endothelial-lined sacs develop from evaginations of the first brachial pouch to form the tympanic cavity mucosal folds and ossicular suspensory ligaments. These sacs contact each other, defining the various pouches, spaces, and compartments that divide the middle ear (Fig. 140.4).
The most common locations of origin of cholesteatomas in decreasing frequency are the posterior epitympanum, the posterior mesotympanum, and the anterior epitympanum (38). Epitympanum cholesteatomas originate in a shallow pocket that lies between the pars flaccida of the tympanic membrane and the neck of the malleus. This pouch, known as Prussak’s space, has as its floor the lateral process of the malleus and its associated mucosal folds lying in the horizontal plane. Cholesteatomas most commonly exit Prussak’s space by the posterior route: the cholesteatoma penetrates the superior incudal space lateral to the body of the incus. From there, it traverses the aditus ad antrum to enter the mastoid (Fig. 140.5). The cholesteatoma may reach the middle ear by descending through the floor of Prussak’s space into the posterior space of von Troeltsch, a pouch lying between the tympanic membrane and the posterior mallear fold, the inferior edge of which contains the chorda tympani nerve (Fig. 140.4). This pouch contains a medial, superior, and lateral wall but is open to the mesotympanum
P.2085

inferiorly toward the posterior mesotympanum. Cholesteatomas in this region may involve the stapes, round window, sinus tympani, and facial recess.
Figure 140.5 Posterior epitympanic cholesteatoma passing through the superior incudal space and the aditus ad antrum.
The second most common site of origin of cholesteatomas is the posterior mesotympanum (Fig. 140.6). The pars tensa retracts into the mesotympanum to form a cholesteatoma sac that passes medial to the malleus and the incus. Cholesteatomas in this region invade the sinus tympani and facial recess. The sinus tympani lies between the facial nerve and the medial wall of the mesotympanum. The facial recess is bounded by the fossa incudis and the facial nerve medially and the chorda tympani nerve laterally. Both areas are difficult to access surgically (Fig. 140.7) and are common sites of residual cholesteatoma.
Anterior epitympanic cholesteatomas develop as a retraction pocket anterior to the malleus head. The anterior epitympanic space or supratubal recess is limited anteriorly by the middle cranial fossa, the petrous tip, and the root of the zygoma; posteriorly by a bony ridge, termed the cog, extending to the cochleariform process; superiorly by the middle cranial fossa; and laterally by the tympanic bone and chorda tympani nerve. The floor of the anterior epitympanum is intimately associated with the horizontal portion of the facial nerve. Cholesteatomas in this region can therefore cause a facial paresis or paralysis (39). Anterior epitympanic cholesteatomas extend to the supratubal recess of the middle ear via the anterior pouch of von Troeltsch, a shallow pouch lying between the tympanic membrane and the anterior mallear fold (Fig. 140.8). If the area anterior to the malleus head is not explored thoroughly during tympanomastoidectomy, cholesteatomas in this region can be overlooked.
Prevention
A retraction pocket secondary to eustachian tube dysfunction precedes the development of acquired cholesteatoma. It is good practice to aggressively manage such retraction pockets. A tympanostomy tube should be inserted early in an effort to resolve the negative middle ear pressure and to return the tympanic membrane to a neutral position (Fig. 140.9). However, many retraction pockets persist after tube placement. If the retraction pocket adheres to the ossicles or surrounding structures, it will not reverse. Similarly, if the tympanic membrane has been retracted for a long time and loses all its elasticity, it will not revert to a normal appearance. Tube placement is best done under general anesthesia, where the retraction pocket may be seen to distend as the patient is masked with positive-pressure ventilation. A T-tube or some other long-term ventilation tube is often necessary. If the retraction pocket does not distend with positive pressure ventilation, then it should be examined carefully to determine the extent and depth of the pocket. Mirror examination or the use of a 90-degree telescope may be used to see hidden borders of the pocket. Most retraction pockets extend into the epitympanum or sinus tympani. If the pocket persists despite tympanostomy tube placement, then surgical exploration may be indicated.
Preoperative Evaluation
The presence of a cholesteatoma requires surgical management unless advanced age or poor health prohibits an operation. Both congenital and acquired cholesteatomas are asymptomatic during early development. Careful questioning of a patient with a middle ear cholesteatoma often reveals many years of subtle ear symptoms, beginning with a progressive hearing loss (usually unilateral). Unilateral hearing loss may be ignored until the cholesteatoma becomes infected secondary to water contamination or an upper respiratory infection, producing a foul-smelling otorrhea. When an infected cholesteatoma is present or there is bone destruction, the purulent discharge tends to be thick, scanty, and fetid. An occasional patient will ignore the disease until impending complications develop, heralded by the onset of pain, bloody otorrhea, vertigo, headache, facial paresis, or the appearance of a polyp at the meatus.
Figure 140.6 Posterior mesotympanic cholesteatoma invading the sinus tympani and facial recess.
P.2086

The microscopic examination of the ear is the most important diagnostic maneuver in evaluating the presence of a cholesteatoma. The ear must first be meticulously cleaned with cotton-tipped applicators or suction. Acquired cholesteatomas will be noted in the attic or Shrapnell area and in the posterior-superior region, where they are usually associated with erosion of the bony canal. Granulation tissue may arise from the diseased bone of the outer attic wall or scutum or from the posterior bony wall of the external auditory meatus, where it overhangs the facial recess. A polyp consisting of a mass of edematous granulation tissue may protrude through an attic defect. The polyp may continue to enlarge and in fact may extrude through the meatus. If the disease is very extensive, the entire attic and mastoid antrum will be filled with granulation tissue, and the underlying bone will become necrotic and friable over a wide area. General anesthesia may be required in children to perform an adequate examination. Pneumatic otoscopy
P.2087

should be performed in every patient with a cholesteatoma. A positive fistula response characterized by vertigo and nystagmus is very suggestive of erosion into the inner ear, especially the horizontal semicircular canal or less commonly the cochlea. Infected cholesteatomas characterized by fetid, foul-smelling otorrhea and cholesteatomas associated with polyps should be initially managed medically. Dry ears are much easier to operate on than wet, infected ears. Polyps can be removed with great care in the clinic with microscopic visualization by using a snare, suction, or small cup forceps, or they may be cauterized. They should never be aggressively pulled out by grasping them because they may be connected to an important underlying structure such as an ossicle or the facial nerve. A vasoconstricting agent applied to a wick will control bleeding. An attic cholesteatoma may be obscured by a crust that looks like cerumen. Removing the crust reveals a whitish keratin mass typical of a cholesteatoma.
Figure 140.7 Posterior mesotympanic cholesteatoma involving the facial recess and sinus tympani. VII, facial nerve.
Figure 140.8 Anterior epitympanic cholesteatoma (arrow) with extension to the geniculate ganglion.
Figure 140.9 A: Reversal of a posterosuperior retraction pocket with a tympanostomy tube.B: Persistence of a retraction pocket despite tympanostomy tube placement.
Weber and Rinne tests using a 512-Hz tuning fork should be performed and correlated with the audiogram. Preoperative and postoperative audiometric evaluations are essential and should include air and bone thresholds, speech reception threshold, and word recognition. A conductive deficit in excess of 35 dB indicates ossicular discontinuity, usually secondary to destruction of the long process of the incus or the capitulum of the stapes. Alternatively, only a mild conductive hearing loss may be present despite incus erosion if sound is passing through the cholesteatoma directly to the stapes.
The surgical preparation of the patient with an infected cholesteatoma begins with a topical antibiotic drop. Oral quinolones such as ciprofloxacin and levofloxacin are effective with P. aeruginosa but are often unnecessary. For medical therapy to be effective, aural toilet is essential. Irrigating the ear with half-strength white vinegar can be effective in controlling infection.
Successful surgical management of cholesteatoma includes exteriorization and removal of all trapped keratinizing epithelium. The goals of surgery should be carefully reviewed with the patient preoperatively. The primary objectives of surgery are a safe, dry ear, with hearing
P.2088

improvement a secondary goal. Specific goals include the following (Table 140.2):
TABLE 140.2 SURGICAL GOALS FOR CHOLESTEATOMA
Treat complications
Remove diseased tissue
Obtain a dry “safe” ear
Preserve normal anatomy
Improve hearing
  • Treating complications that have already supervened (extradural abscess, brain abscess, facial nerve palsy, and labyrinthitis)
  • Removing diseased bone, mucosa, granulation polyps, and cholesteatoma to allow drainage and prevent extension of disease to vital structures
  • Stopping the discharge permanently
  • Preserving as much normal anatomy as possible (e.g., posterior canal wall)
  • Preserving or improving hearing
Patients should be carefully counseled about the possible adverse outcomes of surgery: facial paralysis, dysgeusia, vertigo, further hearing loss, tinnitus, recurrent and residual cholesteatoma, cerebrospinal fluid (CSF) leak, and meningitis. The chronic nature of the disease and the need for prolonged follow-up should be stressed. If a mastoid cavity is created, water precautions and the possible need for cavity debridement every 6 to 12 months must be mentioned. The need for second-stage procedures for residual cholesteatoma or ossicular chain reconstruction should be discussed with the patient and performed when appropriate.
Thin-section (1-mm) computed tomography (CT) scans without contrast, taken in the coronal and axial projections, are often of value in the preoperative assessment of cholesteatomas. It must be emphasized that routine CT scanning is not advocated for cholesteatoma diagnosis, although several alterations of temporal bone anatomy frequently are associated with it. Among these, erosion of the scutum and expansion of the antrum within areas of air cell breakdown and soft tissue density are characteristic. Other features may include ossicular destruction, erosion of the facial canal, mastoid tegmen dehiscence, and erosion into the otic capsule, especially over the horizontal semicircular canal. CT scanning is important in complicated disease and in the evaluation of cholesteatomas and other masses behind an intact tympanic membrane or when the clinical history correlates poorly with physical findings.
Surgical Management
Surgical treatment of the mastoid in patients with cholesteatoma has gradually evolved. Before the development of the surgical microscope and the electric drill, significant morbidity, including facial paralysis, profound sensorineural hearing loss, and dural tears, attended surgery of the temporal bone. Understandably, otologic surgeons of that day were reluctant to pursue complete removal of cholesteatomas, so a philosophy of exteriorization of cholesteatomas without complete removal emerged. This led to progressive hearing loss and chronically draining ears, requiring constant supervision.
To avoid cavity problems altogether, the canal-wall-up (CWU) facial recess approach was developed. The posterior canal wall was preserved at all costs. A second stage was planned in 6 to 18 months for removal of residual disease and reconstruction of the ossicular chain. Experience with this philosophy over the past 20 years has resulted in a rethinking of this position by many prominent otologists. A high rate of recidivism approaching 36% in some series (40,41,42,43,44,45,46) has resulted in a more individualized approach. Instead of using the same procedure on every ear with cholesteatoma, the procedure is adapted to the extent of disease. The specific operation is determined by local ear factors, general medical factors, and the skill of the surgeon. The local ear factors include the extent of the cholesteatoma, presence of a fistula, clinical assessment of eustachian tube function, degree of mastoid pneumatization, and the degree of neurosensory hearing loss in both ears. General factors include the patient’s general medical condition, occupation, and reliability (Table 140.3). The CWU procedure involves preserving the posterior canal wall with or without a posterior tympanotomy (facial recess approach). The posterior tympanotomy is performed through a triangle bounded by the fossa incudis, facial nerve, and chorda tympani nerve. The CWU procedure is indicated in patients with a well-pneumatized mastoid and middle ear space. Relative contraindications to the CWU procedure include a sclerotic mastoid, a labyrinthine fistula, an only hearing ear, and poor eustachian tube function (47,48,49).
The canal-wall-down (CWD) procedure involves taking down the posterior canal wall to the vertical facial nerve and
P.2089

marsupializing the mastoid into the external ear canal. In a CWD procedure, all accessible air cells are meticulously exenterated. CWD procedures can be divided into those in which the middle ear space is preserved (modified radical mastoidectomy) and those in which the middle ear space is eliminated and the eustachian tube plugged (radical mastoidectomy). A more limited procedure is the atticotomy, which involves the removal of the lateral wall of the epitympanum (scutum) to the limits of the cholesteatoma. To prevent recurrent cholesteatoma, the atticotomy defect is blocked with cartilage. A more extensive attic cholesteatoma that is lateral to the ossicles and accompanied by a sclerotic mastoid may be managed with a Bondy procedure. This involves the removal of the scutum and portion of the posterior canal wall with preservation of the ossicles and middle ear space. The bony defect is not reconstructed; rather, the cholesteatoma matrix is exteriorized. A patient with a cholesteatoma and poor eustachian tube function as evidenced by absence of middle ear aeration and a sclerotic mastoid should have a CWD procedure (Table 140.4).
TABLE 140.3 DETERMINANTS OF OPERATIVE TECHNIQUE FOR CHOLESTEATOMA
Local factors
   Presence of a fistula
   Extent of disease
   Eustachian tube function
   Mastoid pneumatization
   Hearing status of both ears
General factors
   General medical condition
   Occupation
   Reliability
Skill and experience of the surgeon
TABLE 140.4 SURGICAL APPROACHES TO CHOLESTEATOMA
Canal-wall-up
   Complete mastoidectomy
   Facial recess approach
Canal-wall-down
   Modified radical mastoidectomy
   Radical mastoidectomy
Other
   Atticotomy
   Bondy procedure
   Canal-wall-reconstruction
Several variations of a canal-wall-reconstruction (CWR) procedure have recently been developed to improve exposure and removal of cholesteatoma as in a CWD approach while retaining the benefits of an intact canal wall (improved hearing and avoidance of the bowl cavity) (50,51,52,53,54,55,56,57,58,59,60,61,62,63,64). In these procedures, a complete mastoidectomy including a facial recess is performed and the posterior canal is removed. The cholesteatoma, the ossicles, and the tympanic membrane are addressed, and the posterior canal wall is replaced. Some surgeons opt to fill the mastoid cavity with bone pate or hydroxyapatite, whereas others leave it open as in a CWU procedure. These techniques have even been used to “repair” radical mastoid cavities. See Chapter 141 for a more complete description of surgical approaches to the mastoid.
Complications and Emergencies
As cholesteatomas expand and become infected, they cause ossicular chain destruction, exposure of the membranous labyrinth, tegmen dehiscence, exposure of the facial nerve, and infection of the mastoid and intracranial spaces (Table 140.5).
TABLE 140.5 COMPLICATIONS AND EMERGENCIES CHOLESTEATOMA
Conductive and sensorineural hearing loss
Labyrinthine fistula
Vertigo
Facial paralysis
Intratemporal infection
Intracranial infection
Brain herniation
Hearing Loss
Some degree of ossicular chain erosion occurs in most cases of cholesteatoma. Attic cholesteatomas involve the head of the malleus and body of the incus early. As the cholesteatoma expands inferiorly, the lenticular process of the incus and the stapes superstructure are eroded. Pars tensa cholesteatomas that develop from a posterior-superior retraction pocket also involve the lenticular process of the incus and the stapes superstructure. When both of these bones are involved, the hearing loss can be as great as 50 dB. However, if a natural myringostapediopexy develops, then loss may be as little as 20 dB. One should always assume that the ossicular chain is intact in a patient with a cholesteatoma. Cholesteatoma on the lateral surface of the incus can be removed using microsurgical ear instruments without disturbing the ossicular chain. Involvement of the medial surface of the incus often requires removal of the incus by first separating the incudostapedial joint, then the incudomallear joint. Cholesteatoma extending medial to the head of the malleus into the anterior epitympanic space (or supratubal recess) usually requires removal of the incus and the head of the malleus. Removal of cholesteatoma from the stapes should be done last by dissecting parallel with the stapedius tendon in a posterior to anterior direction to avoid dislocating the footplate and causing sensorineural hearing loss. One should avoid superior or inferior movement as well as depression of the stapes. The tympanic membrane is grafted to seal the middle ear, and Silastic sheeting is placed over the promontory to prevent adhesions. A second-stage procedure is performed in 6 to 18 months to remove residual cholesteatoma and reconstruct the ossicular chain. If cholesteatoma removal is certain and the mucosal involvement is minimal, the ossicular chain can be reconstructed at the primary procedure.
Labyrinthine Fistula
A labyrinthine fistula may be found in up to 10% of patients with long-standing cholesteatomas or in revision cases. One should suspect a fistula in patients with chronic
P.2090

ear disease who have sensorineural hearing loss and/or vertigo induced by noise or pressure changes in the middle ear. A positive fistula test with manipulation of the external canal may be present, although its absence does not exclude a fistula. Suppurative labyrinthitis with complete loss of hearing and vestibular function may occur secondary to a fistula from a cholesteatoma. High-resolution, thin-section CT of the temporal bone may reveal a fistula of the semicircular canals or the basal turn of the cochlea. Fistulae of the horizontal semicircular canal are most common (65). The procedure of choice in labyrinthine fistulae is a modified radical (CWD) mastoidectomy. This avoids leaving residual disease concealed in the mastoid cavity and necessitating the patient to undergo multiple procedures. Management of the matrix covering the fistula depends on several factors, including the infection status of the ear, the degree of sensorineural hearing loss in the involved ear as well as the opposite ear, the size and location of the fistula, and the surgeon’s skill. In the patient with a fistula of the only hearing ear, a CWD procedure is performed and the matrix is left intact over the fistula. Attempting to remove it places the patient at significant risk for a permanent total sensorineural hearing loss. If the opposite ear has normal hearing and eustachian tube function, then the surgeon can be more selective in management. If the fistula involves one of the semicircular canals and the mastoid is small, then a CWD mastoidectomy, leaving the matrix on the fistula, is appropriate. If there is a small semicircular canal fistula and the mastoid cavity is large, then the skillful surgeon may elect to perform an intact canal wall procedure, remove the matrix, cover the fistula with fascia, and plan a second procedure. If the hearing is normal, then the matrix covering extensive fistulae of the vestibule or cochlea should be left alone. If cochlear function is profoundly depressed, the matrix should be removed and the fistula covered with fascia. The removal of matrix over the fistula and then immediately covering it with fascia should be the last part of the procedure. Suction should not be used around the fistula site; only blunt dissection is appropriate. If the semicircular canal is inadvertently opened by a drill, then the iatrogenic fistula should be immediately covered with fascia. Parenteral antibiotics and steroids may be helpful. Postoperative vertigo is a sign of labyrinthine and cochlear trauma. A bone-conduction audiogram may be depressed immediately but may recover in 4 to 6 weeks in some cases.
Facial Paralysis
Facial paralysis in patients with cholesteatoma may develop acutely due to infection or slowly due to chronic expansion. In either case, surgery should be performed as soon as the paralysis is recognized. High-resolution, thin-section CT with both axial and coronal scanning will localize the involvement. A common site of nerve involvement is the geniculate ganglion (66). A mastoidectomy with facial recess approach will expose the horizontal and vertical portions of the facial nerve. Removing the cholesteatoma and decompressing the facial nerve are sufficient if the nerve is anatomically intact; opening the sheath of the facial nerve is unnecessary. A middle fossa approach is required for cholesteatomas involving the petrous apex. Intravenous antibiotics and high-dose steroids are helpful. The House-Brackmann facial nerve grading system should be used to assess the degree of facial paralysis, and the intraoperative use of a facial nerve stimulator/monitor is helpful. Iatrogenic injury of the facial nerve at the pyramidal turn may occur with drilling of the mastoid. The horizontal segment of the facial nerve may be injured during blunt removal of the cholesteatoma in the middle ear. Immediate repair is performed when the injury is recognized, and decompression of the facial nerve for several millimeters on either side of the injured segment is recommended. A delayed facial paralysis within a few days of surgery indicates minor trauma, with recovery expected within 6 weeks. These patients are treated like those with idiopathic facial paralysis and given high-dose steroids. Antiviral therapy may also be beneficial.
Infections
Serious infections associated with cholesteatoma include periosteal abscess, lateral sinus thrombosis, meningitis, and intracranial abscess. A high-resolution, thin-section, contrast-enhanced CT scan is performed. Infections of this nature occur in less than 1% of all cholesteatomas because of the widespread use of antibiotics and the tendency to operate earlier. The most dangerous type of infected cholesteatomas are those where drainage through the external auditory canal is obstructed by an inflamed and narrow canal. The egress may be further blocked by mucosal edema, squamous debris, or a polyp. Early intervention to remove cholesteatoma and provide adequate drainage is required.
Periosteal abscess may develop behind a cholesteatoma and inflammation that is blocking the aditus ad antrum or from an extensive cholesteatoma that erodes through the mastoid cortex. It presents as an inflamed, fluctuant postauricular mass. High-dose antibiotics are begun and adjusted according to needle aspiration culture results. Surgery is performed after 24 to 48 hours of antibiotics. It is important to be aware that the dura or lateral sinus may be exposed by disease.
Lateral sinus thrombosis may occur from an infected cholesteatoma. It presents with a characteristic high, spiking fever in a picket-fence pattern. Treatment requires high-dose antibiotics and surgery similar to management of lateral sinus thrombosis in association with acute coalescent mastoiditis. If the cholesteatoma is extensive, a CWD mastoidectomy should be performed (66).
Patients who develop headaches on the side of a cholesteatoma should have a CT scan to rule out an impending intracranial complication. Pain and headache may arise from involvement of dura by the cholesteatoma, by a
P.2091

developing epidural abscess, or because of loculated abscess. Cerebellar or temporal lobe abscesses may exhibit only mild symptoms such as low-grade fever, mild ataxia, or mental changes. Intracranial abscesses should be managed by the neurosurgeon after beginning intravenous antibiotics. After control of the intracranial problem, the otologist can then manage the ear disease. See Chapter 138 for more information on intracranial complications.
Brain Herniation
Brain herniation may develop following previous mastoid procedures presenting as an encephalocele or meningoencephalocele through a defect in the tegmen tympani or tegmen mastoideum. The etiology is thought secondary to aggressive drilling that exposes and traumatizes the dura during previous mastoid surgery. Subsequent brain herniation can be prevented by carefully inspecting any exposed dura for injury. If a tegmen defect is small and the dura is intact, no further treatment is necessary. If there is a disruption in the integrity of the dura with or without a CSF leak, repair is necessary. Many of these defects can be successfully treated from the mastoid. One should circumferentially elevate the dura from the tegmen with a blunt instrument and remove 1 mm of bone from around the site of injury to expose normal-appearing dura. Bleeding is controlled with low-energy bipolar cautery rather than monopolar cautery to avoid injury and thrombosis of cerebral vessels. The surgeon should circumferentially insert temporalis fascia, cut larger than the defect, between the dura superiorly and the tegmen inferiorly. Defects larger than a few millimeters require conchal cartilage or a bone chip for support to prevent herniation. If an established encephalocele or meningoencephalocele is encountered, it should be removed. A biopsy is needed to confirm brain tissue and rule out a malignancy. One should carefully dissect the circumference of the mass to identify its site of origin. In most cases, the encephalocele in the epitympanum or mastoid is necrotic and functionless. The herniated brain tissue is removed to the level of the tegmen and dural defect and repaired as described previously. For larger defects, a mini-craniotomy is performed by making an opening in the squamosa laterally, just above the plane of the tegmen. The dura can then be elevated off the floor of the middle fossa and the defect repaired with fascia and cartilage or bone.
References
1. Kuhn A. Das Cholesteatom des Ohres. Zeitschr Ohrenheilk 1891; 21:231.
2. Derlacki EL, Clemis JD. Congenital cholesteatoma of the middle ear and mastoid. Ann Otol Rhinol Laryngol 1965;74:706–727.
3. Levenson MJ, Michaels L, Parisier SC, et al. Congenital cholesteatomas in children: an embryologic correlation. Laryngoscope 1988;98:949–955.
4. Levenson MJ, Michaels L, Parisier SC. Congenital cholesteatomas of the middle ear in children: origin and management. Otolaryngol Clin North Am 1989;22:941–954.
5. Teed FW. Cholesteatoma verum tympani (its relationship to the first epibranchial placode). Arch Otolaryngol 1936;24:455–474.
6. Michaels L. An epidermoid formation in the developing middle ear: possible source of cholesteatoma. J Otolaryngol 1986;15:169–174.
7. Michaels L. Origin of congenital cholesteatoma from a normally occurring epidermoid rest in the developing middle ear. Int J Pediatr Otorhinolaryngol 1988;15:51–65.
8. Karmody CS, Byahatti SV, Blevins N, et al. The origin of congenital cholesteatoma. Am J Otol 1998;19:292–297.
9. Lee TS, Liang JN, Michaels L, et al. The epidermoid formation and its affinity to congenital cholesteatoma. Clin Otolaryngol Allied Sci 1998;23:449–454.
10. Wang RG, Hawke M, Kwok P. The epidermoid formation (Michaels’ structure) in the developing middle ear. J Otolaryngol 1987;16:327–330.
11. Aimi K. Role of the tympanic ring in the pathogenesis of congenital cholesteatoma. Laryngoscope 1983;93:1140–1146.
12. Fisch U. ‘Congenital’ cholesteatomas of the supralabyrinthine region. Clin Otolaryngol Allied Sci 1978;3:369–376.
13. Bluestone CD, Klein JO. Intratemporal complications and sequelae of otitis media. In: Bluestone CD, Stool SE, eds. Pediatric otolaryngology. Philadelphia: WB Saunders, 1990:521–526.
14. Sheahan P, Blayney AW, Sheahan JN, et al. Sequelae of otitis media with effusion among children with cleft lip and/or cleft palate. Clin Otolaryngol Allied Sci 2002;27:494–500.
15. Goldman JL, Martinez SA, Ganzel TM. Eustachian tube dysfunction and its sequelae in patients with cleft palate. South Med J 1993;86:1236–1237.
16. Dominguez S, Harker LA. Incidence of cholesteatoma with cleft palate. Ann Otol Rhinol Laryngol 1988;97[6 Pt 1]:659–660.
17. Vartiainen E, Karja J. Bilateral chronic otitis media. Arch Oto Rhino Laryngol 1986;243:190–193.
P.2092

18. Wittmaack K. Wie entsteht ein genuines Cholesteatoma? Arch Ohren Nasen Dehlkopfh 1933;137:306.
19. Glasscock ME. Pathology and clinical course of inflammatory disease of the middle ear. In: Shambaugh G, Glasscock ME, eds. Surgery of the ear. Philadelphia: WB Saunders, 1990:178.
20. Vennix PP, Kuijpers W, Tonnaer EL, et al. Cytokeratins in induced epidermoid formations and cholesteatoma lesions. Arch Otolaryngol Head Neck Surg 1990;116:560–565.
21. Palva T, Karma P, Makinen J. The invasion theory in cholesteatoma and mastoid surgery. In: Sade J, ed. Cholesteatoma and mastoid surgery. Proceedings of the Second International Conference on Cholesteatoma and Mastoid Surgery. Amsterdam: Kugler Publications, 1982:249–264.
22. Michaels L. Biology of cholesteatoma. Otolaryngol Clin North Am 1989;22:869–881.
23. Orisek BS, Chole RA. Pressures exerted by experimental cholesteatomas. Arch Otolaryngol Head Neck Surg 1987;113:386–391.
24. Wolfman DE, Chole RA. Osteoclast stimulation by positivemiddle-ear air pressure. Arch Otolaryngol Head Neck Surg 1986;112:1037–1042.
25. Chole RA, McGinn MD, Tinling SP. Pressure-induced bone resorption in the middle ear. Ann Otol Rhinol Laryngol 1985;94[2 Pt 1]:165–170.
26. Tanaka Y, Kojima H, Miyazaki H, et al. Roles of cytokines and cell cycle regulating substances in proliferation of cholesteatoma epithelium. Laryngoscope 1999;109[7 Pt 1]:1102–1107.
27. Yetiser S, Satar B, Aydin N. Expression of epidermal growth factor, tumor necrosis factor-alpha, and interleukin-1alpha in chronic otitis media with or without cholesteatoma. Otol Neurotol 2002;23:647–652.
28. Akimoto R, Pawankar R, Yagi T, et al. Acquired and congenital cholesteatoma: determination of tumor necrosis factor-alpha, intercellular adhesion molecule-1, interleukin-1-alpha and lymphocyte functional antigen-1 in the inflammatory process. J Oto-Rhino-Laryngol Related Specialties 2000;62:257–265.
29. Albino AP, Reed JA, Bogdany JK, et al. Increased numbers of mast cells in human middle ear cholesteatomas: implications for treatment. Am J Otol 1998;19:266–272.
30. Albino AP, Kimmelman CP, Parisier SC. Cholesteatoma: a molecular and cellular puzzle. Am J Otol 1998;19:7–19.
31. Amar MS, Wishahi HF, Zakhary MM. Clinical and biochemical studies of bone destruction in cholesteatoma. J Laryngol Otol 1996;110:534–539.
32. Bujia J, Kim C, Ostos P, et al. Role of interleukin 6 in epithelial hyperproliferation and bone resorption in middle ear cholesteatomas. Eur Arch Oto-Rhino-Laryngol 1996;253(3):152–157.
33. Yan SD, Huang CC. The role of tumor necrosis factor-alpha in bone resorption of cholesteatoma. Am J Otolaryngol 1991;12:83–89.
34. Iino Y, Toriyama M, Ogawa H, et al. Cholesteatoma debris as an activator of human monocytes. Potentiation of the production of tumor necrosis factor. Acta Oto-Laryngol 1990;110:410–415.
35. Hamzei M, Ventriglia G, Hagnia M, et al. Osteoclast stimulating and differentiating factors in human cholesteatoma. Laryngoscope 2003;113:436–442.
36. Jung JY, Chole RA. Bone resorption in chronic otitis media: the role of the osteoclast. J Oto-Rhino-Laryngol Related Specialties 2002;64:95–107.
37. Chole RA. Cellular and subcellular events of bone resorption in human and experimental cholesteatoma: the role of osteoclasts. Laryngoscope 1984;94:76–95.
38. Jackler RK. The surgical anatomy of cholesteatoma. Otolaryngol Clin North Am 1989;22:883–896.
39. Chu FW, Jackler RK. Anterior epitympanic cholesteatoma with facial paralysis: a characteristic growth pattern. Laryngoscope 1988;98:274–279.
40. Cruz OL, Kasse CA, Leonhart FD. Efficacy of surgical treatment of chronic otitis media. Otolaryngol Head Neck Surg 2003;128:263–266.
41. Silvola J, Palva T. One-stage revision surgery for pediatric cholesteatoma: long-term results and comparison with primary surgery. Int J Pediatr Otorhinolaryngol 2000;56:135–139.
42. Stangerup SE, Drozdziewicz D, Tos M, et al. Recurrence of attic cholesteatoma: different methods of estimating recurrence rates. Otolaryngol Head Neck Surg 2000;123:283–287.
43. Darrouzet V, Duclos JY, Portmann D, et al. Preference for the closed technique in the management of cholesteatoma of the middle ear in children: a retrospective study of 215 consecutive patients treated over 10 years. Am J Otol 2000;21:474–481.
44. Vartiainen E. Factors associated with recurrence of cholesteatoma. J Laryngol Otol 1995;109:590–592.
45. Rosenfeld RM, Moura RL, Bluestone CD. Predictors of residual-recurrent cholesteatoma in children. Arch Otolaryngol Head Neck Surg 1992;118:384–391.
46. Brown JS. A ten year statistical follow-up of 1142 consecutive cases of cholesteatoma: the closed vs. the open technique. Laryngoscope 1982;92:390–396.
47. Brackmann DE. Tympanoplasty with mastoidectomy: canal wall up procedures. Am J Otol 1993;14:380–382.
48. Dawes PJ, Leaper M. Paediatric small cavity mastoid surgery: second look tympanotomy. Int J Pediatr Otorhinolaryngol 2004;68:143–148.
49. McDonald TJ, Cody DTR. Surgery of the temporal bone air cell system: mastoid and petrosa. Otolaryngol Head Neck Surg 1986;4:3081.
50. Gantz BJ, Wilkinson EP, Hansen MR. Canal wall reconstruction typanomastoidectomy with mastoid obiteration. Laryngoscope 2005;115:1734–1740.
51. Babighian G. Posterior and attic wall osteoplasty: hearing results and recurrence rates in cholesteatoma. Otol Neurotol 2002;23(1):14–17.
52. Black B. Mastoidectomy elimination. Laryngoscope 1995;105[12 Pt 2 Suppl 76]:1–30.
53. Dornhoffer JL. Retrograde mastoidectomy with canal wall reconstruction: a single-stage technique for cholesteatoma removal. Ann Otol Rhinol Laryngol 2000;109:1033–1039.
54. Grote JJ, van Blitterswijk CA. Reconstruction of the posterior auditory canal wall with a hydroxyapatite prosthesis. Ann Otol Rhinol Laryngol Suppl 1986;123:6–9.
55. Hartwein J, Hormann K. A technique for the reconstruction of the posterior canal wall and mastoid obliteration in radical cavity surgery. Am J Otol 1990;11:169–173.
56. Hosoi H, Murata K, Kimura H, et al. Long-term observation after soft posterior meatal wall reconstruction in ears with cholesteatoma. J Laryngol Otol 1998;112:31–35.
57. Ikeda M, Yoshida S, Ikui A, et al. Canal wall down tympanoplasty with canal reconstruction for middle-ear cholesteatoma: post-operative hearing, cholesteatoma recurrence, and status of re-aeration of reconstructed middle-ear cavity. J Laryngol Otol 2003; 117:249–255.
58. Leatherman BD, Dornhoffer JL, Fan CY, et al. Demineralized bone matrix as an alternative for mastoid obliteration and posterior canal wall reconstruction: results in an animal model. Otol Neurotol 2001;22:731–736.
59. Magliulo G, Ronzoni R, Vingolo GM, et al. Reconstruction of old radical cavities. Am J Otol 1992;13:288–291.
60. Magliulo G, D’Amico R, Forino M. Reconstruction of the posterior auditory canal with hydroxyapatite-coated titanium. J Otolaryngol 2001;30:330–333.
61. Mercke U. The cholesteatomatous ear one year after surgery with obliteration technique. Am J Otol 1987;8:534–536.
62. Roberson JB Jr, Mason TP, Stidham KR. Mastoid obliteration: autogenous cranial bone pate reconstruction. Otol Neurotol 2003;24:132–140.
63. Takahashi H, Hasebe S, Sudo M, et al. Soft-wall reconstruction for cholesteatoma surgery: reappraisal. Am J Otol 2000;21:28–31.
64. Wiet RJ, Harvey SA, Pyle MG. Canal wall reconstruction: a newer implantation technique. Laryngoscope 1993;103:594–599.
65. Farrior JB. Surgery for cholesteatoma: complications in otolaryngology-head and neck surgery. Toronto: BC Decker, 1986.
66. Harker LA, Koontz FP. Bacteriology of cholesteatoma: clinical significance. Trans Sect Otolaryngol 1977;84[4 Pt 1]:ORL-683–686.