Endoscopic mastoid surgery is difficult to learn, performed in a tight space, and will probably never replace conventional open procedures. That’s the bad news. The good news is that it is a less invasive second-look procedure than conventional surgery, it is bone-sparing, and it can reduce the frequency with which an otolaryngologist does open repeat procedures.
Explore This IssueMay 2007
In separate interviews with ENToday, two experts in endoscopic mastoid surgery discussed their experiences and their views on the place this approach has in mastoid surgery, and offered pearls that can help otolaryngologists and their surgical teams make a smooth transition to using endoscopy in mastoid procedures.
The endoscopic approach allows us to see around corners and use angled instruments that are not possible with the conventional approach, said Hamed Sajjadi, MD, in a phone interview. We reduce the amount of bone that is lost in a conventional resection, and we can even reduce the need for open procedures by as much as 70 percent. Dr. Sajjadi is Clinical Associate Professor of Otolaryngology-Head and Neck Surgery at Stanford University School of Medicine and has a private practice in San Jose, CA. He gave a presentation on endoscopic mastoid surgery at the 2006 annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery.1
In that presentation, Dr. Sajjadi discussed the results of combined ear endoscopic and microscopic methods in 250 consecutive cholesteatoma cases over a seven-year period. He then compared those results with more than 500 cholesteatoma cases that were performed in prior years with standard microscopic methods, and that therefore served as historical controls. In particular, he wanted to assess the degree of surgical dissection during primary surgery, the cholesteatoma recidivism rates, and the need to perform open secondary mastoid procedures during second-look surgery in surgeries with and without endoscopes.
Repeat Open Procedures Reduced
Dr. Sajjadi found that adding endoscopy to the standard microscopic surgery for cholesteatoma reduced by 80% the need to open up the mastoid during planned second-look surgeries (p = 0.005).
To perform endoscopic mastoid surgery, the otolaryngologist uses a rigid endoscope attached to a video camera, he said. The surgical field is visualized on a monitor. The procedure starts with a small incision, approximately 1 cm. If the results are clear and no diseased tissue is seen, there is no need to open up the mastoid. The surgeon can choose an instrument angled at 30° or 70°, he said.
Steep Learning Curve
The endoscopic approach is still a tough sell to otolaryngologists, he noted, primarily owing to some awkward logistics and to the time needed to master the procedure. It can be difficult to convince people who are used to conventional mastoid surgery to learn the endoscopic procedure, said Dr. Sajjadi. The learning curve is steep. It’s also a one-handed surgery. You have to hold the endoscope with one hand, while with the microscope, your hands are free.
Otolaryngologists who take on the challenge need to be prepared for longer procedures initially, Dr. Sajjadi said. They also need to shepherd the nursing staff through the transition and to train them to have the endoscopes on hand for second-look mastoid resections. However, this phase is transient, he stressed. After the learning curve is overcome and everyone is trained it may not be longer than conventional surgery, because there is less need for opening up the mastoid.
Endoscopic approaches can actually reduce the surgical time for many patients who have clear mastoids on endoscopy, thus avoiding the time needed to open and close the mastoid, he said.
He also emphasized that the endoscopic approach is used only with second-look surgeries, and not with primary mastoidecomy. In that setting, though, the ability to inspect the original surgical site for residual disease, and the ability to eliminate the need for a repeat open procedure, means that endoscopic mastoid surgery performs a valuable role in the treatment of mastoid disease, he said.
Another expert agreed with Dr. Sajjadi about the adjunctive role of the endoscopic approach. Endoscopic mastoid surgery is really not separate from traditional mastoid surgery, said Thomas J. Haberkamp, MD, in a separate phone interview. It’s performed in the same manner as the conventional procedure, but the endoscope is an adjunct. During or after resection of the cholesteatoma, the endoscope is used to visualize the areas you can’t easily see, such as the sinus tympani and the anterior epitympanum. Dr. Haberkamp is Professor of Otolaryngology at Rush University Medical Center in Chicago and authored one of the key landmark articles describing endoscopic mastoid surgery.2
The initial procedure is typically performed with a drill and an endoscope is used to help remove residual diseased tissue, Dr. Haberkamp said. In addition, we can substitute endoscopes for traditional second-look surgery, in which we look for recurrent disease, he said. We use the endoscope to look into the middle ear with a small postauricular incision. We can also use the endoscopic approach to clean out a cholesterol granuloma and drain the cyst.
The impact of the endoscope has been one of evolution, not revolution, according to Dr. Haberkamp. So far, the endoscope has not changed mastoid surgery the way it has changed sinus surgery, he said.
He agreed with Dr. Sajjadi, though, that the endoscopic approach’s key advantages are greater visualization and the reduced need for more invasive repeat surgeries. It allows us to peer around the corner and see areas we couldn’t before and remove disease, he said. We’re able to avoid more radical surgeries in some cases.
Tight Space, Less Three-Dimensional Visualization
A key disadvantage that differentiates endoscopic mastoid surgery from endoscopic sinus surgery is the small size of the middle ear in relation to that of a sinus cavity. When you’re trying to work in the middle ear, it’s difficult to work with the endoscope and the instrument scooping out disease, Dr. Haberkamp said. The instrument and endoscope take up 25 percent to 30 percent of the space. Also, when you’re looking at the space with the endoscope, you lose the three-dimensional depth of field you have with the microscope, so you can’t always tell the difference between deep and shallow areas of the sinus tympani.
Surgeons should therefore be particularly cautious, he said, noting that he had observed fractures of the ossicles and stapes in training labs, even though he could not recall seeing such fractures in actual surgeries. It takes practice, he stressed. Even though fractures are rare, we should remember the potential for their occurrence and use caution.
He again agreed with Dr. Sajjadi that surgeons should be prepared to invest additional operating time during the learning phase. It takes an extra 20 minutes initially to add the endoscope to traditional techniques, he noted. It is still cost-effective, because you get better visualization and remove more disease.
Unlike repeat mastoid surgeries, endoscopic second-look procedures can be done in the office with a local anesthetic in selected patients, he added.
Dr. Haberkamp noted that the endoscopes used in mastoid procedures are much smaller than conventional sinuscopes: they come in sizes of 1.7 mm, 2.7 mm, and 3.5 mm in diameter. One limitation, though, is that the endoscopes at 70° do not come in the smaller size.
No Separate ICD-9 Code
Both experts pointed out that there is no separate International Classification of Disease-9 (ICD-9) code for endoscopic mastoid surgery. Therefore, the accounting department will need to use the same code as when billing for a standard mastoid procedure. If you bill additionally for the endoscopic, insurance companies vary in how easy it is to get paid, Dr. Haberkamp said.
- Sajjadi H. Endoscopic mastoid surgery in cholesteatoma. AAO-HNS. 2006 (abstract).
- Haberkamp TJ, Tanyeri H. Surgical techniques to facilitate endoscopic second-look mastoidectomy. Laryngoscope 1999;109(7 pt 1):1023-7.
©2007 The Triological Society