ENT Journal Article Review: Stapedotomy and Middle Ear Surgical Procedures 

For busy clinicians, sifting through mounds of scientific literature can take time away from patient care. To make that easier, Marathon Medical is launching a series of review articles that distill and link to some of the practice-changing research coming out for ENT.

Today’s focus is stapedotomy and middle ear surgical procedures. We’re reviewing six recent journal articles about stapedotomy techniques and new tools and prostheses for performing stapedotomies.

Microscopic vs. Endoscopic Approach?

Endoscopic stapedotomy has become much more popular over the past few decades. While endoscopic approaches were initially used just to visualize the stapes before conducting the surgery under a microscope, many surgeons increasingly prefer completely endoscopic stapedotomy.

An endoscopic approach allows better visualization of the middle ear (except for the antrum), better identification of unusual anatomy, and may have lower rates of complications like chorda tympani manipulation, dysgeusia, scutum curettage, and postoperative pain^(1-3). For stapedectomies, endoscopic approaches may eliminate the need for endaural incisions^(4).

There are, however, a few drawbacks to an endoscopic approach. First, a surgeon trained solely with a microscopic approach may encounter a steep learning curve to operating endoscopically with one hand. Additionally, achieving hemostasis can be more difficult using an endoscopic approach.⁽²⁾ More practically, switching to an endoscopic approach requires additional instruments, tools, and training for surgeons and operative staff.

Why Many ENT Surgeons Prefer Endoscopic Approach

Despite these drawbacks, many surgeons increasingly prefer endoscopic approaches for the increased visibility. In 2021, Fan et al. at Mount Sinai published one of the first non-inferiority trials of endoscopic vs microscopic stapedotomy⁽¹⁾. They recruited 22 patients with otosclerosis and an air bone gap (ABG) greater than 20 dB. Eleven underwent microscopic stapedotomy and eleven underwent endoscopic stapedotomy. ABG closure was almost identical between the groups—with no differences in operative time, scutum curettage rates, or postoperative dysgeusia. No patients required chorda tympani sacrifice either. There were similar rates of post-operative tinnitus resolution in both groups.

Another study out of Australia from Vaughan et al. retrospectively reviewed 69 endoscopic stapedectomy cases from 2015 to 2019 within their practice⁽⁴⁾. Compared to other published data, their rates of ABG closure were not significantly different from similar studies using a microscopic approach. There were no incidents of sensorineural hearing loss or facial nerve paralysis. There were similar rates of scutum curettage in both groups. Interestingly, 43% of their cases used both a microscope and an endoscope. After reviewing this data, the authors recommend using this combined approach for difficult cases. The endoscope can help visualize and plan the surgery and the microscopic approach provides more precision when placing the prosthetic footplate.

Key Takeaways:

• • Endoscopic approaches appear to be equally effective and equally safe as the traditional microscopic approach.
  • Endoscopic approaches provide better visualization at the expense of a two-handed operative approach.
  • Using both endoscopic and microscopic approaches may be useful for cases with a high degree of difficulty.

What Type of Prosthesis is Best?

The past 20 years have seen incredible advancements in middle ear prostheses. With all these advancements, which prostheses are best for which cases? We review four articles on different prostheses below.

Nitinol prostheses

Since their introduction in 2004, Nitinol prostheses have become increasingly common. Nitinol is a titanium nickel alloy that can be shaped and adjusted intraoperatively by heating the prosthesis (i.e.) without the need to manually crimp it).

In 2018, Roque Reis and colleagues conducted a meta-analysis looking at Nitinol vs. non-Nitinol prostheses⁽⁵⁾. They reviewed data from 1,385 patients and found that Nitinol prostheses were significantly more effective at closing the ABG than non-Nitinol prostheses (odds ratio 2.56).

Interestingly, they found an even larger difference in effectiveness when looking at ABG closure in the first 3 months after surgery, but no difference when looking at ABG closure from 3 months to 3 years. There were no differences in adverse events between the groups, leading the authors to recommend Nitinol prostheses for their superior ABG closure efficacy.

ALTO prosthesis

Next, we have two studies on the adjustable length titanium ossicular (ALTO) prosthesis from Grace Medical. In 2010, Praetorius et al. described their first experiences with the ALTO prosthesis for ossiculoplasty⁽⁶⁾. While autologous tissue has historically been the gold standard, there are many instances (e.g. cholesteatoma) where using a prosthesis is preferred. Praetorius et al. found that the ability to adjust the length of the prosthesis in real time during the procedure was particularly beneficial because getting the right length for the prosthesis is critical for sound conductance. They felt the ALTO could reduce costs by reducing wasted, incorrectly sized implants. They found no difference in patient outcomes between ALTO and other traditional prostheses.

Another study from Zhao, et al also supported these findings⁽⁷⁾. This paper compared sound conduction profiles of the ALTO prosthesis to intact incuses collected from cadavers. The ALTO performed almost identically to the cadaveric incuses, one of the first devices to have comparable efficacy to human tissue prostheses.

Finally, we’ll finish with a study from Smith et al. comparing the titanium bell Partial ossicular replacement prostheses (PORP) with the hydroxylapatite HAPEX PORP⁽⁸⁾. The HAPEX device requires gel foam to mount it, which can affect longevity and sound conduction. The titanium PORP was designed to be free-standing and eliminate the need for gel foam as an additional stabilizer. The study compared about 500 cases with the HAPEX device to 40 cases with the titanium device. They found the titanium device led to better hearing results, especially at lower frequencies. The authors hypothesized that this might indicate less postoperative fibrosis with the titanium device.

Key Takeaways:

• •  Nitinol prostheses outperformed non-Nitinol prostheses and may be easier to shape and place during surgeries.
  • The ALTO device performs as well as autologous tissue, allows for intraoperative shaping, and can reduce operating costs and waste.
  • The titanium PORP eliminates the need for gel foam and performs better than the original HAPEX PORP.