Stapedotomy

Let’s now look at a case of an endoscopic stapedotomy. This is a 74-year-old male with progressive bilateral hearing loss that began in his 30s. He has no history of ear disease or prior surgery, no dizziness, and he’s not happy with his hearing aids due to feedback and how loud he needs to turn them up. His left ear is his worst hearing ear. His audiogram shows a mixed hearing loss with a large conductive component and absent acoustic reflexes. He maintained decent speech discrimination. These surgical steps will now be shown in detail.

A standard tympanomeatal flap is raised with canal incisions at 12 o’clock and six o’clock. Upon entering the middle ear it’s important to palpate the ossicular chain. This confirms mobility of the malleus and incus as well as fixation of the stapes. Even with the endoscopic approach it’s necessary to curette the scutum. This helps maximize visualization so as to provide room for instrumentation. The incudostapedial joint is then divided. The stapedial tendon is then divided. This is done with a CO2 laser. Next the posterior crus of the stapes is divided, again with a CO2 laser on a setting of four watts.

After confirming the posterior crus has been divided, the stapes superstructure is down-fractured. After down-fracturing, the footplate is closely examined to make sure it has not been avulsed. A rosette pattern is then formed on the staples foot plate, again using a CO2 laser, but this time on a setting of two watts. After the foot plate has been weakened, it’s then time to proceed with the stapedotomy.

The technique shown here uses graduated perforators to dilate the stapedotomy size. The hole should be 0.1 millimeter greater than the eventual prosthesis. The size is confirmed with the use of a sound. The prosthesis is then atraumatically guided into the middle air space. The technique shown here uses Grace Medical’s feather VAC suction. This has been designed to fit under the bend of their Eclipse piston. The prosthesis can be released by simply taking your thumb off the suction port. The nitinol prosthesis is then crimped using the CO2 laser, and care is taken to make sure that it is strongly adhered to the incus. This case required one extra shot to confirm that adherence.

This gentleman’s three month post-operative audiogram reveals significant closure of his air bone gap. Let’s now look at a second case to review some of the key steps. This is a 55-year-old female with progressive left-sided hearing loss that began in her ‘30s. She has no significant otologic history and she was not interested in hearing aids. Her audiogram reveals a left mixed hearing loss with a large air bound gap. Acoustic reflexes were absent.

Her three month post-op audiogram shown on the right shows significant reduction in her air bound gap. It’s also interesting to note the improvement in her bone conduction. The third case of an endoscopic stapedotomy is a 54-year-old female with left-sided hearing loss. About 15 years ago she had had left stapes surgery with initial hearing improvement but this declined over time. The CT scan did not show any obvious problem. Her audiogram shows a left mixed hearing loss with a significant air bone gap. Revision stapes surgery presents a unique challenge.

First you must identify the source of the hearing loss. Here the previous wire prosthesis is noted to be loose. Additionally, there’s partial incus necrosis. Adhesions are lysed to get better access to the foot plate. Use of a laser can be helpful in lysing these adhesions and keeping a dry surgical field. Eventually the old prosthesis will need to be removed. This should be done as delicately as possible so as to not avulse the stapes foot plate or damage the inner ear.

In this case the stapes foot plate was largely intact, so I proceeded with a stapedotomy technique. If the stapes foot plate is avulsed or loose, you may consider switching to a stapedectomy technique. This will be shown in the next segment.

In addition to the foot plate, the surgeon must consider the health of the incus during revision surgery. In this case there was partial incus necrosis, therefore I chose a wider ribbon prosthesis, and placed it more proximal on the long process of the incus where the bone appeared healthy. If the incus is not viable, then you must use a malleo-vestibulopexy, in which case the prostheses bridges from the neck of the malleus down to the stapedotomy.

Three month post-op audiogram, shown on the right, demonstrates correction of her air bone gap.