This news release on a study of surgical techniques for cochlear implants and their long-term effects offers very little detail for assessing the study’s validity and relevance. A close reading of the study itself contains much useful detail, as well as important cautions that needed to be covered in the release. An omission on the authors’ conflict of interests with device manufacturers and some inaccuracies about the study (misstating the number of patients involved, for example) leaves the release with some room for improvement.
Having cochlear implants to preserve hearing is vital for many patients, so it is important to assess which types of implant or surgical techniques are best to maintain hearing over the long term. This release, however, doesn’t go very far in answering these questions.
Surgery can be costly itself as well as all the related expenses that follow from it so knowing the overall costs is very important. No costs are mentioned.
Two types of benefits are discussed in the news release.
The study looked at 230 patients (it was actually 196 patients but 225 implants) with “every type of cochlear implant, including three FDA-approved implants that use different types of electrodes to stimulate the auditory nerve.” The benefits were not quantified but we are told that the researchers “found that electrodes designed with no wire (called lateral wall electrodes) performed the best in maintaining residual hearing in the inner ear, compared to electrodes made with wire.” How much better? We don’t know.
The other benefit compares “cochleostomy” (which requires drilling into the bone to get inside the inner ear) versus the “round window” approach and “the round window approach had a much better chance of keeping their residual hearing in the long term.”
How much better? We aren’t told.
Drilling into your ear to implant a device can involve harm. As for harms, we learn of them only obliquely with this phrase: “the non-wire electrodes were less traumatic, causing less injury and minimizing fractures inside the inner ear.” Are we to presume that the wire electrode implants can be “more traumatic?” More detail was definitely needed here.
The favored “round window” approach is also considered safer given that the news release reports that “the cochleostomy approach causes fibrosis and scarring, leading to hearing loss over time,” according to the lead researcher. How much harm? We don’t know.
The news release provides no information about the quality of the evidence. Was this an observational study? A clinical trial? Reading the published study, we see a number of sources of potential bias, including the fact that patients were not randomized to electrode type or surgical approach. If one wonders if the experience of the surgeon might be a factor, the study noted that since they are a high volume center, which performs many cochleostomies, then “inexperience with this surgical approach is unlikely to impact results.” The study also lost patients to follow up, likely underestimating hearing preservation rates. It would have been good to include this in the news release.
No obvious disease mongering here.
We know that the lead researcher is with the Department of Otolaryngology-Head and Neck Surgery at New York Eye and Ear Infirmary of Mount Sinai (NYEE) and Mount Sinai Beth Israel, as well as the Center for Hearing and Balance and Ear Institute at Mount Sinai Health System and that he had a team of researchers from Vanderbilt University.
The release doesn’t tell us if any any of the researchers or their institutions have any conflicts of interest in either the surgical technique or the type of cochlear implants studied in this trial.
According to the published study, four of the authors, including the first author and the senior author, have financial conflicts of interest in the form of consulting arrangements with cochlear device companies.
There are a variety of ways to treat hearing loss besides cochlear implants but, outside of the mention of oral steroids (with no detail given), none are mentioned.
Are these types of surgeries or cochlear implants available anywhere in the US? We have no idea from reading this news release.
The news release doesn’t tell us anything about the novelty of the wireless cochlear implants nor that of the “round window” (where surgeons open the membrane without bone removal or drilling in the inner ear) and “cochleostomy” (which requires drilling into the bone to get inside the inner ear). Are these new procedures? What other research has been done on them? Where is the context that establishes the place of these in the current landscape of hearing-preservation technologies?
The release doesn’t engage in sensational language. But absent any numbers to describe the benefits or details about the evidence and what makes any of the approaches novel, the release doesn’t explain what makes this study a “breakthrough.”