Stapedotomy (Endaural)
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Table of Contents
Otosclerosis is a condition characterized by abnormal bone growth that inhibits the movement of the stapes, leading to a gradual conductive hearing loss. The treatment options encompass observation, the use of hearing aids, and surgical intervention. If the patient opts for surgery, either a stapedotomy or a stapedectomy can be executed to liberate the stapes from the sclerotic bone. In the case of a stapedotomy performed with an endaural approach, access to the middle ear is gained through a minor incision extending from the anterior ear canal to the incisura, also known as the intertragal notch. The surgeon then proceeds to remove the superstructure of the stapes, create an opening in the footplate of the stapes, and subsequently place a prosthesis into the opening, which is then connected to the incus. The outcomes of this procedure are generally positive, with 90–95% of patients experiencing an improvement in hearing.
Conductive hearing loss; otosclerosis; stapedectomy; minimally invasive surgery; otology; air-bone gap.
The middle ear contains three small bones known as ossicles: the malleus, incus, and stapes. These bones play a vital role in hearing by transmitting vibrations from the tympanic membrane to the oval window of the middle ear. The stapes is the smallest bone in the human body and it connects the incus to the oval window. Disruption of the conduction of vibrations from the tympanic membrane to the middle ear leads to conductive hearing loss. One potential cause of conductive hearing loss is otosclerosis, which occurs in about 10% of the Caucasian population; it is less common in the Japanese and South American populations and rare in African Americans.1 In patients with otosclerosis, abnormal growth of bone results in stapes footplate fixation.1-3 Stapes fixation prevents the ear’s normal conducting mechanism, leading to progressive hearing loss, tinnitus, and dizziness.1
Treatment of otosclerosis includes observation, hearing aids, and surgery. The standard surgical intervention for otosclerosis is either complete stapes removal (stapedectomy) or footplate fenestration (stapedotomy) and replacement with a prosthetic implant.4 Stapes superstructure is removed and replaced by a prosthesis thus restoring conduction and hearing in both procedures. Numerous studies have demonstrated the high rates of success and long-term stability of both procedures; however, compared to stapedectomy, stapedotomy has been shown to provide better high frequency hearing improvement and lower complication rates.4,5 Removal of the stapes can be accomplished under microscopy using lasers or micro drills. In a stapedotomy, the stapes superstructure is removed, and a fenestration is made in the footplate. A stapes prosthesis is then inserted into the fenestration and affixed to the incus.
In a stapedotomy or stapedectomy, the middle ear can be accessed by an endaural or transcanal approach.5 In an endaural approach, as discussed here, the stapes is accessed through an incision extending from the anterior ear canal to the incisura (intertragal notch). The postaural approach utilizes a curved incision in the postauricular sulcus. A transcanal approach uses a skin incision 8–10 mm lateral to the tympanic membrane to access the stapes, which provides limited visualization of the stapes superstructure.5 The selected approach is typically based on patient and surgeon preferences.
Patients with otosclerosis will typically present with gradually progressive hearing loss that can be either symmetric or asymmetric. Patients may also describe improved hearing in noisy environments (paracusis of Willis).6 Some patients may have a family history of otosclerosis, as studies have suggested an autosomal dominant inheritance pattern with variable penetrance.7
Patients with otosclerosis will have normal external ears and normal external acoustic canals on a physical exam. Tympanic membranes will be pearly white, clear, not retracted or bulging, and without signs of inflammation. A Webber and Rinne test with a 512-Hz tuning fork will show bone conduction greater than air conduction in the affected ear, with lateralization to the side of the affected ear (negative test [abnormal]).3,4,6 An audiogram will show conductive or mixed hearing loss ≥ 25 db across all frequencies. Additionally, assessing the acoustic reflex can be achieved by presenting an acoustically loud sound and assessing the contraction of the stapedius muscle. A positive early deflection on acoustic reflex assessment is a distinctive sign of otosclerosis. Otomicroscopy may be performed to assess the movement of the ossicles and to rule out perforation as a cause of conductive hearing loss. While otomicroscopy is an essential part of a thorough ear examination, it is not specifically used to rule out effusion. Instead, tympanometry is the preferred method to detect the presence of an effusion.3
Temporal bone computerized tomography (CT) scans are used selectively when considering surgery in children and in patients with congenital stapes fixation.6 CT can also be used to rule out X-linked perilymphatic (CSF) gusher syndrome and superior semicircular canal dehiscence, which are both contraindications and not amenable to stapedotomy.6
Patients with otosclerosis will typically present with progressive hearing loss that typically begins in the 4th decade of life.3 Two-thirds of patients are female, and a majority present with bilateral hearing loss.
Options for treatment of otosclerosis include observation, hearing aids to amplify audio, and surgical intervention.3,6
The goal of treatment is to improve hearing, although surgery is not expected to reverse tinnitus.3,6
Patients are strongly considered for surgery if they have conductive hearing loss with negative (abnormal) Rinne test that has been shown to be secondary to stapes footplate fixation. Additionally, patients with adequate bone conduction thresholds and good speech thresholds and word recognition on audiometric testing are good surgical candidates.3,6 Stapedotomy is contraindicated in patients with active middle ear infections, tympanic membrane perforation, inner ear malformation, or endolymphatic hydrops (Meniere’s Disease).
Dr. John Shea was the first to perform a stapedectomy in 1959.4 Since its advent, innovations in techniques, prosthesis materials, and design have improved safety and outcomes. Subsequent advancements in prosthesis materials as well as the emergence of microdrills and lasers enabled surgeons to remove only a piece of the stapes and bore a small hole in the footplate in order to install a piston-shaped prosthesis, and thus the stapedotomy was created. In studies comparing stapedotomy and stapedectomy outcomes, the stapedotomy was found to provide better high frequency hearing improvement and lower complication rates.4,5
Stapedotomy can be performed either under general or local anesthesia, depending on patient health status and preference. The patient's position is made so that the surgeon can see directly down the ear canal from a sitting position. After prepping and draping, an incision is made from the anterior ear canal to the incisura (intertragal notch), and hemostasis is achieved with bipolar cautery. Then, the bony cartilaginous junction is exposed using both blunt and sharp dissection. Soft tissue is elevated inferiorly along the subperiosteal plane using a House Lancet to create a tympanomeatal flap. Excess fascia is removed to avoid the development of a canal cholesteatoma, a collection of keratinaceous debris beneath the skin that may cause otorrhea and pain. The tympanomeatal flap is advanced to the tympanic annulus, which is then elevated to provide access to the middle ear space. Movement of the ossicles is assessed to confirm stapes fixation. A bone curette is then used to remove bone from the bony external auditory canal to provide better exposure and allow visualization of the entire ossicular chain, stapedial tendon, facial nerve, and round window. Care is taken to avoid damage to the chorda tympani, which would result in taste disturbance. The distance is measured from the footplate to the long process of the incus for prosthesis fitting. A CO2 laser with Waveguide fiber set to a low power setting (4 W, 100-ms pulse duration) is then used to remove the posterior crus of the stapes and sever the stapedial tendon. Then, the stapedotomy is performed using either the laser or a microdrill to make an aperture in the stapes footplate. The piston of the stapes prosthesis is inserted into the stapedotomy, and the crozet is positioned over the incus and crimped into place using the laser or manual crimping if necessary. Fascia is placed into the oval window to seal it and prevent a perilymph fistula. The incision is closed and saline-soaked Gelfoam is placed along the edges of the tympanic membrane flap to maintain its position. The incision is well hidden in the intertragal notch. Total operating time is roughly 90 minutes, and blood loss is typically minimal.
Postoperatively, the patient may be discharged home on the same day or be admitted for overnight observation, depending on surgeon preference.6 Patients should avoid activities that cause pressure changes (nose blowing, airplane travel, SCUBA diving) and prevent water from entering their ear for 3–4 weeks. Post-op follow-up generally occurs at 1 month and 3–4 months after surgery to assess surgical site, facial nerve function, and for full audiometry. Complications from surgery include but are not limited to: sensorineural hearing loss (0.2–3%, may be profound), facial nerve damage (very rare), chorda tympani nerve damage resulting in permanent or temporary dysgeusia (30%), incus necrosis, tinnitus, vertigo, disequilibrium, serous/suppurative labyrinthitis, and reparative granuloma.3,6,8 Nausea and vertigo can be managed with antiemetics.
Several studies have demonstrated the safety and effectiveness of the stapedotomy.1,2,4,8 Outcomes are favorable; closure of air-bone gap within 10–15 db is achieved in 90–95% of patients. Hearing is unchanged in 10% and worse in 1%, and 1% of patients will lose hearing after surgery.3
Stapedotomy exists as a minimally-invasive surgical treatment for otosclerosis with excellent outcomes and long-term success in most patients. The endaural approach provides excellent visualization of the stapes and surrounding structures, thus optimizing safety and efficiency. Exciting advancements in technology and techniques continue to improve stapedotomy outcomes and safety, such as Laser STAMP prosthesis-free procedure that have shown promising results.4 In laser STAMP procedure an HGM argon laser is used to vaporize the anterior crus of the stapes and the anterior third of the footplate, ensuring complete transection and mobility of the posterior two-thirds of the footplate, followed by sealing the perilymph space with adipose tissue.10
Special equipment for this procedure includes:6,9
- Standard microscopic ear tray instruments.
- Laser: CO2 or iridium.
- Microdrill: 0.6–0.8 mm.
- Stapes prosthesis: many types exist; selection is typically based on surgeon preference.
- Measuring rod: to measure the distance between the stapedial footplate and the incus.
- McGee stapes crimpers: to secure prosthesis (if a wire loop is used).
Author C. Scott Brown also works as editor of the Otolaryngology section of the Journal of Medical Insight.
The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.
Citations
- Adedeji TO, Indorewala S, Indorewala A, Nemade G. Stapedotomy and its effect on hearing - our experience with 54 cases. Afr Health Sci. 2016;16(1):276-281. doi:10.4314/ahs.v16i1.36.
- Hammerschlag PE, Fishman A, Scheer AA. A review of 308 cases of revision stapedectomy. Laryngoscope. 1998;108(12):1794-1800. doi:10.1097/00005537-199812000-00006.
- Pasha R, Golub JS. Otolaryngology: Head and Neck Surgery: Clinical Reference Guide. 5th ed. San Diego, CA: Plural Publishing, Inc.; 2022.
- Cheng HCS, Agrawal SK, Parnes LS. Stapedectomy versus stapedotomy. Otolaryngol Clin North Am. 2018;51(2):375-392. doi:10.1016/j.otc.2017.11.008.
- Bhardwaj A, Anant A, Bharadwaj N, Gupta A, Gupta S. Stapedotomy using a 4 mm endoscope: any advantage over a microscope? J Laryngol Otol. 2018;132(9):807-811. doi:10.1017/S0022215118001548.
- Iowa Head and Neck Protocols: Stapedotomy. University of Iowa Health Care website. Updated November 7, 2018. Accessed May 22, 2021. Available at: https://medicine.uiowa.edu/iowaprotocols/stapedotomy.
- Ealy M, Chen W, Ryu GY, Yoon JG, Welling DB, Hansen M, Madan A, Smith RJ. Gene expression analysis of human otosclerotic stapedial footplates. Hear Res. 2008 Jun;240(1-2):80-6. Epub 2008 Mar 15. doi:10.1016/j.heares.2008.03.001.
- Brown KD, Gantz BJ. Hearing results after stapedotomy with a nitinol piston prosthesis. Otolaryngol Head Neck Surg. 2007 Aug;133(8):758-62. doi:10.1001/archotol.133.8.758
- Kavanagh K. Ear Instrument Course: Stapedectomy. ENT USA website. Updated August 18, 2017. Accessed June 1, 2021.
- Silverstein H, Jackson LE, Conlon WS, Rosenberg SI, Thompson JH Jr. Laser stapedotomy minus prosthesis (laser STAMP): absence of refixation. Otol Neurotol. 2002;23(2):152-157. doi:10.1097/00129492-200203000-00008.
Cite this article
Kaylie DM, Thompson TA, Brown CS. Stapedotomy (endaural). J Med Insight. 2024;2024(271). doi:10.24296/jomi/271.
Procedure Outline
Table of Contents
- Canal Injections
- Incisions
- Prosthesis Measurements
- Separate Joint and Tendon
- Remove Stapes Superstructure
- Drill Footplate
- Patient Counseling
Transcription
CHAPTER 1
Alright, so we are going to do an endaural stapedotomy on this patient's left ear and start with the injection.
Let me have suction first. 40. Prepped. Alright, can I have the bed towards me, please? Other way. There we go. Alright, that's good. And I'll take injection. So we'll infiltrate the ear canal with 1% lidocaine with 1:100,000 epinephrine. And prior to starting, I injected the intertragal notch to get the area where I'm going to get- make the endaural incisions. So one of the benefits of an endaural approach for stapedotomy is, get a lot of exposure. For patients who have narrow ear canals, it really gives you an advantage over a transcanal approach. Let me have suction. And it's a very commonly-used approach for any middle ear work, commonly used throughout the world. Less so in the United States, but it's - something that really does have a lot of advantages. So, the incisions will be - uh, let me have a Gimmick?
And could I have the bed away a little bit, please? Alright, that's good. I am focusing on the drum now. So here's our malleus at 12 o'clock. And so we'll have an incision that'll come up here, up the ear canal, and into the intertragal notch. And then there'll be a second incision, which will be along posteriorly here, and we'll raise a flap that'll get us into the middle ear. So, what I'll start with is the external incision. Let me have a knife? So, the intertragal notch- the incision will go right between- I'm sorry, not the intertragal notch, the tragus and the helical root, and right where that crease is, that incision will go there, and when it heals, it'll be nicely hidden. A 15 blade? So, start in the ear canal. Get this incision down to the bone. Let me have a- let me have a sponge. Get this dried up. Great. Let me have a Weitie. So start by just kind of getting some exposure here. Do you have a suction? And a Bovie? Get the exposure down to the bone. Here. And let me have a Lempert. Okay, that should actually give the exposure we need up here. So- actually, I'm going to go back to microscope. Alright. So now I want to continue this incision. Let me have a straight Beaver. So this incision goes right to 12 o'clock, right at the top of the malleus. Let me have a round Beaver. And then this incision goes from the top- midway up the bony-cartilaginous junction. Alright, let me have a Freer. So now we elevate this soft tissue up.
CHAPTER 2
This posterior soft tissue. Let me see the scissors. Alright. Let me see the Freer again? Okay, now I'm going to re-place this retractor. Can I have the suction? And a Freer? So here's the lateral bone in the ear canal, and here's my flap. Let me have a pickup? So they make special retractors that are smaller- for- transcanal incision - for endaural incisions like this. Suction? Which would be helpful to have. Alright. Freer? So you see, now we get back and get exposure this way all the way to the mastoid, and so, technically you could do a mastoidectomy through this approach. It'll be a little difficult, but that's certainly done. Alright, I'll take the bed away, please. So now we're going to focus on the eardrum. I'll take a 20 suction. And you see here's our flap. And we can elevate this- inferiorly and get into the middle ear space. So we'll take a #2. As we elevate this. Let me see the scissors. Get rid of these straggly- bits, these can- become problematic later, you know- if it doesn't lay flat, you can get a canal cholesteatoma. Alright, number- #2? I like this instrument because you can use the point to dig things out and then the flat side to push. It's called a House Lancet. Commonly we just call it a #2, where a sickle knife is a #1. It's just a convention we have, but it's technically called a House Lancet instrument. So we're getting up near the annulus. Just want to be very careful because it's very fragile. This canal skin is very thin. Digging out the annulus right there. I'm getting into the middle ear space. It's very fragile here. There's our chorda tympani. Scissors. Okay, and we see in the dep - uh, let me have a Gimmick.
CHAPTER 3
A House annulus elevator. Can I see the scissors again? Let me see a Gimmick again. So here we have exposure. There's the round window. This is chorda tympani. Here's stapes. And so when I'm moving the undersurface of the malleus right here- let me get a better view of that- so here's the malleus, and when I move that, I see that the incus moves, but the stapes does not. Let me have a Rosen. Can I have the bed towards me, please? Alright. So, here's the incus, and there's the stapes, and there's a fairly large scutum here that we're going to have to remove to get a little better view of it. But what I can feel is- when I press on this incus, the incus moves, but the stapes does not. And you want to press- you want to press in an in-and-out motion, not side-to-side, because even on a fixed stapes, you can rock it side-to-side, but it's really the motion- that way, and you see the joint moving- let me zoom in on that. Bed away just a little bit. Alright. So when I- press there, the joint moves, but the stapes does not. So, what I would like is a curette.
CHAPTER 4
This is a bone curette. And this can be done... So what I want to do is be able to mobilize the- chorda without evulsing it, and in a right-handed surgeon, in a left ear this can be very difficult because your natural curetting motion is right to left, and in a right ear that means you're curetting towards the- chorda. So you want to be very careful curetting around it. But by doing that, you'll get a lot better exposure. So what I want - what I'm looking for is exposure- of the- stapes, the facial nerve, and the round window. Let me have a Rosen. So you see here, there's- so mobilize the- chorda some, but there's this bone here, so I can move the chorda out of the way- and let me have a curette- and remove this ledge of bone, which will help me have better exposure. That was very soft. That's helpful. And now I can see the stapedius tendon and move the chorda. Okay. Curette a little more superiorly. And now I can see- the facial nerve. Let me have a Rosen. Right down in there, that's the facial nerve. And I see the stapedius tendon there, and the posterior crus, and the oval window. Let me see a curette again. And I can see the pyramidal eminence down here, which is where the stapedius tendon comes out. So, at this point we get our laser ready. So, I've- let me have a Gimmick again. So at this point I have all the exposure I need and I know that I can proceed safely. I see that the whole stapes- the stapes is not moving. There's a better view of it now. I see the facial nerve and I have a good view of the round window. So I know that there's enough room that the facial nerve is not prolapsed over the rou- oval window- I'm sorry, I should say oval window- it's not prolapsed over that, preventing- safe placement of a prosthesis. So what I do is, I will laser the stapes footplate- first I would like the measuring stick. 4.5 mm, yeah.
CHAPTER 5
And what I do is I measure- from the footplate- So I'm touching the footplate, and that goes to the top of the incus. And that's 4.5 mm. So the stapes prostheses are measured from the undersurface of the incus, so if this is 4.5 mm, what I'll need is a 4.25-mm prosthesis, which is pretty much what I use standard. Because I do a stapedotomy, and that's generally about the distance that I find most of these end up being, to give the proper- proper length of prosthesis. Alright, so next we're going to get the laser.
So I set- I use a CO2 laser with a- Waveguide fiber. And I set it at- it's at 4 watts? Yes. So it's at- yeah, 4 watts is a pretty low power setting for a 100-ms pulse duration. I do not use continuous pulses because that could really cause damage. But CO2 laser is very effective for stapes because the energy of a CO2 laser is absorbed very quickly by water, so if you were to get through the- through the footplate into the vestibule, you won't damage the underlying structures, whereas other laser- shorter wavelength lasers could damage the underlying structures. Alright, so- hold the chorda out of the way and laser on. Alright, so I cut the tendon. And there's a lot of vessels right here over the joint, which'll bleed, so I just kind of diffusely- get those, which will help prevent bleeding. Alright, standby. Now before I- laser the posterior crus, I like to separate the joint. So I'll take a joint knife. So this is a very small, round knife. And I just separate that. Alright. I'll take the laser.
So now I'm going to laser the posterior crus. Laser on. So for proper laser safety, everyone has goggles that are appropriate for this laser wavelength. And the laser operator knows that- does nothing unless I say "laser on" and "standby." So we have a good system here, so we have good laser safety. There we go. So, I'll take a Rosen. Standby. So now the posterior crura is- or crus. Well, the posterior limb is- crus is singular. Alright. So there- see, it's separated here. And I just downfracture that. And that removes. And I'll take an Alligator. That's right, crura is plural, crus is singular. So, now we're looking right down at the footplate.
Let me have a Gimmick. Actually, no, I'm good. Yeah, that's fine. Alright. So now we have the incus floating there. So now I switch to the small drill. We'll take the 0.6-mm drill bit. So the- I use a DragonFly drill for the- to make the stapedotomy, and the- the stapes prosthesis has a 0.5-mm diameter, so I use a 0.6-mm burr to make a perfectly-sized hole that the prosthesis will then go into. And you can open up the prosthesis, as well. The one that we preselected. I'll take the drill. So I want to center the hole where I'm going to make the stapedotomy directly under the incus. And I'm trying to position my hand so I'm not blocking my vision. There we go. There's the hole. Alright, I'll take the prosthesis.
CHAPTER 6
Alright. Let me have a- let me have a crimper. So what I'll do is I'll crimp it into place on the incus. Let me have a Rosen. Okay. Crimper. Rosen. Crimper. There we go. Right into place. So, let me have a Rosen. So now we need to take the- suction. Take this fascia. And place this down in the oval window to seal it around the prosthesis to prevent a CSF leak- I mean, sorry, purulent fistula. And that is how you do it.
CHAPTER 7
Alright, so this is how you close this incision. Make- get some deep bites here to reapproximate the muscle and the soft tissue. And then- See, that brings that- nicely reapproximates that. We'll reapproximate this tissue. I see them back 3-weeks postop. And I- generally like to get a hearing test then.
And I have a - a lot that I counsel the patients about. This is very safe procedure, but there are risks to it, and one of the risks is loss of hearing. And so, that's something I want to know about right away. So I tell the patients that when they get home, they should- their hearing's not going to be quite as good because of all the ointment and surgical healing it needs to do, but I want them to get a sense of where their hearing is when they first get home. And if their hearing should drop, if they feel like their hearing gets worse, particularly if they start getting really dizzy when they weren't dizzy, that can be a sign of a reparative granuloma. And that's something that needs to be treated right away. Okay, I'll take a 4-0. And so- you can come out with that. So I tell them I- if that happens, I want them to call, even if it's the middle of the night. And we'll start them on Prednisone and antibiotic - oral antibiotics, and they should be on their- already on their drops. They should already have the drops. And then they need to come in right away for a hearing test. So if they live far away, they need to have one locally and sent to us. So they need to do it that day, or, if it's the middle of the night, the next day. And if there's a sensorineural loss, we need to evaluate them. You want the dressing, a cotton ball, and a Band-Aid? Yeah. So these incisions heal very nicely, and they're all hidden in the natural skin crease between the helical root and the tragus. And now I'll take the 5-0 fast. I'm going to do- just a skin suture here. Some interrupteds. With a 5-0 fast absorbing gut suture. Leave a little tail on those, because those will come unraveled. One more ought to do it.