During the last 50 years, the debate over the merits of canal-wall-up (CWU) versus canal-wall-down (CWD) surgery for removing pediatric cholesteatomas has shifted focus several times.
Explore this issue:May 2010
The traditional pro/con arguments are familiar to most otolaryngologists. The major advantage of the CWU procedure is that it preserves the canal wall and other key structures of the middle ear. That preservation enables patients to get the ear wet and eliminates the need for repeated cleaning of the large surgical cavity left behind by the more invasive CWD approach. Hearing results are also purported to be better in CWU-treated patients, although studies are split on whether that is truly a distinguishing factor.
The major downside to the CWU approach is a high rate of recurrent disease, ranging up to 50 percent in some studies and clinical experience. The recurrences often occur because it is difficult to see the entire middle ear and epitympanum when the canal wall is left intact during surgery. As a result, disease is left behind and can recur six to 12 months later.
Historically, for most otolaryngologists, adopting either the CWD or CWU approach has hinged on the amount of weight they placed on these risks and benefits. More recently, however, a new argument has been injected into the debate: whether newer, hybrid approaches that combine the best aspects of CWU and CWD surgery should become the standard of care for treating pediatric cholesteatomas.
Surgeons, Take Your Corners
Bruce Gantz, MD, FACS, professor and head of the University of Iowa Department of Otolaryngology—Head and Neck Surgery in Iowa City, is one of several leading otolaryngologists who have adopted a hybrid approach. His technique, tympanomastoidectomy followed by canal wall reconstruction and mastoid obliteration, is detailed in the Iowa Head and Neck Protocols (http://wiki.uiowa.edu/display/protocols).
Dr. Gantz said that about 90 percent of the patients in his practice can be managed with canal wall reconstruction. During the procedure, the canal wall is taken down with a microsaw, Dr. Gantz explained. This technique provides a view similar to a canal-wall-down exposure and allows the best possible view for total cholesteatoma removal. The ear is then reconstructed by putting the canal wall back in, blocking the attic with a bone graft from the mastoid tip and obliterating the mastoid with bone pâté. “It isolates the attic and mastoid from the tympanum, which prevents recurrent retraction of the tympanic membrane, a major cause of recurrent disease in children with poorly functioning Eustachian tubes,” he explained. A second-look surgery is done six to eight months later to assess results and complete aspects of the reconstruction.