The initial goal of treatment for cholesteatomas is to reduce the level of the inflammatory and infectious activity in the involved ear. The mainstays of medical treatment are to remove infected debris from the ear canal, keep all water out of the ears to prevent further contamination, and apply ototopical agents that cover the usual bacterial organisms, which include P aeruginosa, streptococci, staphylococci, Proteus, Enterobacter, and anaerobes. Commercially available agents such as ofloxacin or neomycin-polymyxin B are usually adequate. If the middle ear is exposed, there is a theoretical danger of causing ototoxicity with the use of agents such as aminoglycosides. This risk has not been studied adequately but appears to be relatively low in cases of chronic inflammation; however, it may be in the patient's best interest to avoid ototoxic agents and instead use agents such as ofloxacin.
Some physicians favor the additional use of topical steroid agents to reduce both the level of inflammation and the volume of any inflammatory tissues that are present. The efficacy of this treatment modality has not been studied adequately, but in theory, the anti-inflammatory effects could be beneficial. However, it is also theoretically possible that steroids may inhibit the local immune responses, allowing progression of the infectious process.
In many cases, the infection fails to subside completely. This situation usually occurs in the presence of a cholesteatoma sac with infected keratin debris that is not effectively treated by any local or systemic agents. However, after surgical treatment, the otorrhea usually resolves.
The definitive treatment of cholesteatoma should achieve several goals. The primary goal is to create a “dry and safe” ear. Essentially, this means that the processes that are causing bone erosion, chronic inflammation, and infection should be reversed permanently. To achieve this goal, all cholesteatoma matrices must be either removed or exteriorized. Failure to accomplish this usually results in persistent or recurrent disease. If a cholesteatoma matrix is exteriorized, as in cases of canal-wall-down tympanomastoidectomy or atticotomy, the cavity should be designed to be relatively self-cleaning so that it will not be prone to develop chronic otorrhea. A summary of surgical approaches is shown in Table 50–1.
Table 50–1. Overview of Surgical Procedures for Cholesteatoma. |Favorite Table|Download (.pdf)
Table 50–1. Overview of Surgical Procedures for Cholesteatoma.
|Procedure||End Result||Advantages after Surgery||Disadvantages after Surgery|
|Tympanoplasty (canal wall up) with mastoidectomy||Ear canal with tympanic membrane||Low risk of otorrhea||Risk of recurrent pars flaccida cholesteatoma|
|Atticotomy||Ear canal with tympanic membrane and defect into epitympanum||Intermediate risk of otorrhea||Risk of recurrent pars flaccida cholesteatoma|
|Modified radical mastoidectomy (canal wall down)||Mastoid cavity with tympanic membrane||Low chance of recurrent pars flaccida cholesteatoma||Significant risk of otorrhea|
|Radical mastoidectomy (canal wall down)||Mastoid cavity without tympanic membrane||Low chance of recurrent pars flaccida and pars tensa cholesteatoma||Significant risk of otorrhea and poor hearing|
Cholesteatoma can involve any area of the middle ear, hypotympanum, protympanum, epitympanum, and mastoid. Since most cases of cholesteatoma arise from a retraction of the tympanic membrane, it follows that most cases involve the middle ear space in some form. Pars flaccida retractions are the most common. These cholesteatomas typically invade Prussak's space, which is the area between the pars flaccida laterally and the malleus neck and the lower portion of the head medially. From here, the cholesteatoma can invade the middle ear inferiorly, the attic, and then the mastoid superiorly.
The most common location of cholesteatoma in the middle ear is in the area around the stapes superstructure and incus long process. This area is usually difficult to dissect because of the presence of the facial nerve and ossicular chain. The facial recess, sinus tympani, and posterior hypotympanum are also areas where the surgeon can easily leave behind cholesteatoma because surgical access to these locations is quite limited (Figure 50–4). The remainder of the mesotympanum is usually accessed without difficulty.
Diagram showing the anatomy of the posterior mesotympanum. Note the location of the facial nerve and ossicular chain.
After the mesotympanum, the epitympanum is the next most common location for cholesteatoma. The ossicular chain usually obstructs adequate visualization in this area, but removal of the incus and malleus head significantly improves the exposure. The area anterior to the malleus head can harbor cholesteatoma that can escape the surgeon's attention unless this area is adequately exposed. In some cases, the tegmen is so inferiorly positioned that access to the epitympanum is not adequate without removing the posterior and superior canal wall.
The mastoid can contain a large amount of cholesteatoma, but access to the mastoid is relatively straightforward using standard otologic techniques (Figure 50–5). In some cases, a very low tegmen and very anterior sigmoid sinus can make the surgical exposure inadequate, in which case the canal wall will need to be removed. Once the horizontal semicircular canal has been identified, the surgeon will become oriented to important structures such as the facial nerve and the remainder of the labyrinth.
Diagram of the exposure obtained during a canal-wall-up mastoidectomy of the right ear. A cholesteatoma arising from the pars flaccida and extending into the mesotympanum, the epitympanum, and the mastoid is depicted.
Occasionally, the cholesteatoma invades the petrous apex through various air cell tracts. These include the subarcuate, retrolabyrinthine, supralabyrinthine, retrofacial, and infralabyrinthine tract. Petrous apex cholesteatomas usually cannot be accessed adequately using standard otologic techniques and may require neurotologic dissections, such as a middle fossa craniotomy.
The surgical exposure for cholesteatoma surgery usually requires either a postauricular or an endaural incision.
Care must be taken during dissection of the posterior-superior mesotympanum to avoid injury to the horizontal course of the facial nerve and the stapes or stapes footplate. The facial nerve in the horizontal segment is at greatest risk for surgical injury since dehiscences of the fallopian canal are common here. In general, identification of the horizontal course of the facial nerve in a severely diseased middle ear is easiest from the antrum and attic, just anterior and inferior to the horizontal semicircular canal.
Facial Recess and Epitympanum
Adequate exposure of the posterior-superior mesotympanum usually requires dissection of the facial recess. This can be accomplished with either the canal-wall-up or canal-wall-down tympanomastoidectomy in most cases. The canal-wall-down technique provides reliable access to this area. If the canal wall is kept up, the facial recess exposure needs to be extended into the attic by removing the incus buttress and the incus itself to provide adequate exposure.
The epitympanum is usually best exposed using the canal-wall-down technique, but an adequate exposure is usually obtainable using the canal-wall-up technique as long as there is adequate space between the top of the external auditory canal and the tegmen.
Canal Wall Considerations
The issue of whether a canal-wall-up or a canal-wall-down surgery should be performed is based on various factors. The first consideration relates to the surgeon's training level and experience often influences the choice. The second consideration is the anatomy of the patient's temporal bone. In some cases, adequate exposure can be obtained with either approach, in which case the surgeon may choose the approach based on other factors. In other cases, the canal-wall-down approach is necessary because anatomic features such as a low tegmen or an anterior sigmoid sinus do not allow adequate exposure with any other technique.
The third consideration in surgical approach is the issue of recurrent disease and recidivistic (residual) disease. There are diverse opinions about whether the canal-wall-up procedure leads to a higher incidence of recurrent or residual disease (or both). In general, the canal-wall-down procedure provides superior surgical exposure during chronic ear surgery, but in select cases, the canal-wall-up procedure with appropriate facial recess and epitympanum dissection provides an equivalent level of exposure. There are conflicting reports on whether the incidence of residual disease is higher in canal-wall-up cases, but the results are likely highly dependent on individual surgical techniques and the experience of the surgeon. However, there is compelling evidence that recurrence of cholesteatoma arising from the pars flaccida after the initial surgical treatment (new disease) is significantly higher in patients who have undergone the canal-wall-up procedure. Currently, this type of recurrence can be prevented only by performing canal-wall-down surgery, which essentially exteriorizes potential areas of recurrence such as the attic and the mastoid, or by obliterating these areas if the canal-wall-up or a canal-wall-reconstruction technique is used.
A cholesteatoma recurrence from the pars tensa is a less common problem, but this should be an important consideration, especially if the initial cholesteatoma was of this type. The preventive options include inserting a ventilation tube, placing cartilage grafts to stiffen the tympanic membrane, or obliterating the middle ear space by performing a radical mastoidectomy. The radical mastoidectomy is the most effective technique for preventing pars flaccida retractions, but this approach is not used routinely because patients' postoperative hearing results are uniformly poor.
The canal-wall-down tympanomastoid surgery, whether it is a radical or modified radical mastoidectomy, results in a mastoid cavity. There is a substantial amount of data pointing to a relatively high incidence of otorrhea and debris collection in mastoid cavities, even without the presence of residual or recurrent cholesteatoma. There are many suggested causes for this, but the most common causes, excluding cholesteatoma, are anatomic problems such as a high facial ridge and the presence of mucosal tissue within the mastoid cavity. Anatomic problems occur as a result of technical failure by the surgeon in creating an appropriately shaped mastoid cavity. The mastoid cavity must not have any residual bony ledges, which could cause the retention of squamous debris. A meatoplasty that allows for the adequate inspection and cleaning of the cavity in the office setting is also critical. The formation of mucosal tissue within the mastoid cavity typically occurs when a canal-wall-down procedure is performed in a mastoid that is well pneumatized, and therefore, a canal-wall-up surgery should be considered in these cases.
If the canal wall must be taken down, options include reconstructing the canal wall, obliterating the mastoid cavity with local flaps, such as the temporalis muscle or mastoid periosteum, and covering all exposed areas of mucosa with fascia grafts. The key concept in preventing mucosal overgrowth within the mastoid cavity is to suppress the growth of mucosa by removal or coverage.
Another controversial area in the surgical treatment of cholesteatoma is whether treatment should be staged. The reasons for planning a second surgical procedure include removal of any residual cholesteatoma and the reconstruction of the ossicular chain. Although complete cholesteatoma removal is the goal during the primary procedure, the surgeon, in some cases, may suspect that small pieces of cholesteatoma that are not readily visible could have been left in the surgical field. The most common areas of recurrence include the mesotympanum, in the area of the ossicular chain, and secondarily in the epitympanum. Residual disease in the mastoid is much less common.
Second-look surgery, usually performed 8–12 months after the initial surgery, is often performed after canal-wall-up surgery and less commonly performed after canal-wall-down surgery. The mastoid and epitympanum are highly unlikely to harbor residual cholesteatoma if these areas have been adequately exteriorized during the initial surgery.
A reason for delaying the ossicular chain reconstruction is to prevent adhesion formation around the reconstruction, which may adversely affect the hearing results. If there has been significant mucosal damage in the area of the oval window niche, the surgeon may elect to place a sheet of polymeric silicone (ie, Silastic) or other material to allow the mucosa to heal and form an adequately aerated middle ear space. Once this has been achieved, the surgeon may elect to perform a secondary surgery to reconstruct the ossicular chain. The choice of primary versus delayed ossicular reconstruction is based on the surgeon's experience and the surgical findings.
In general, cholesteatoma in the oval window niche is removed toward the end of the procedure so that management of any potential fistula into the vestibule can be instituted without the risk of compromising the repair during further dissection. The repair of an oval window or round window fistula usually consists of patching the defect with fascia or other soft tissue grafts.
Brown JS. A ten-year statistical follow-up of 1142 consecutive cases of cholesteatoma: The closed vs. the open technique. Laryngoscope.
. (Comparison of results of closed vs. open techniques, showing a difference in recurrence rates.)
Jackler RK. The surgical anatomy of cholesteatoma. Otolaryngol Clin North Am
. (Review of surgical anatomy.)
Quaranta A, Cassano P, Carbonara G. Cholesteatoma surgery: Open vs. closed tympanoplasty. Am J Otol.
. (Comparison of results of closed vs. open techniques, showing no difference in recurrence rates.)