To evaluate the spectral resolution achieved with a cochlear implant in users who were implanted using round window route electrode insertion versus a traditional cochleostomy technique.

Twenty-six patients were classified into two groups according to the surgical approach: one group (n = 13) underwent cochlear implantation via the round window technique and the other group (n = 13) underwent surgery via cochleostomy.

A statistically significant difference was found in spectral ripple discrimination scores between the round window and cochleostomy groups. The round window group performed almost two times better than the cochleostomy group. Differences between Turkish matrix sentence test scores were not statistically significant.

The spectral ripple discrimination scores of patients who had undergone round window cochlear implant electrode insertion were superior to those of patients whose cochlear implants were inserted using a classical cochleostomy technique.

Individuals with superior semi-circular canal syndrome often describe vestibular symptoms elicited by loud sounds, as well as other pressure-induced symptoms. They also often report other symptoms, including autophony, hyperacusis, cognitive dysfunction, spatial disorientation, anxiety and migraine headaches. Symptoms occur due to the presence of a ‘third window’ created by the dehiscence of the superior semi-circular canal. This case report describes a minimally invasive technique to provide soft reinforcement of the round window.

Our patient underwent a permeatal procedure whereby the tympanic membrane was raised to allow inspection of the middle ear. The round window niche was identified and the round window membrane was reinforced with fat. The mucosa of the bony meatus leading to the round window was then disrupted before the application of a double layer of perichondrium to allow further reinforcement.

The case provides support for the use of ‘soft reinforcement’ as a simple and effective technique to treat the symptoms of superior canal dehiscence syndrome.

To compare round window niche visibility as seen endoscopically during cochlear implant surgery with pre-operative high-resolution computed tomography of the temporal bone.

Nineteen patients scheduled for cochlear implantation, aged 2–20 years, were referred for computed tomography from October 2016 to March 2018. Angles were measured between the lines passing through the mid-sagittal plane and cochlear basal turn on the scans. Endoscopic round window niche visibility during posterior tympanotomy was categorised as: type I = 100 per cent, type IIa = more than 50 per cent, type IIb = less than 50 per cent or type III = 0 per cent. Pre-operative computed tomography measurements were used to predict round window niche visibility before surgery and correlated with intra-operative findings.

The mean (range) of pre-operative angles on computed tomography for endoscopic visibility types I, IIa and IIb, were 64.06° (61.16–69.37°), 63.81° (58.61–71.35°) and 56.48° (50.37–59.05°), respectively, a statistically significant finding (one-way analysis of variance test, p = 0.016).

Pre-operative high-resolution temporal bone computed tomography measurements are useful in predicting round window niche visualisation as viewed endoscopically during posterior tympanotomy. The angle was more acute in type IIb compared to type I.

To evaluate the usefulness and reliability of a research software application for the estimation of an individual's cochlear duct length as a basis for electrode selection.

In this prospective cohort study, 21 consecutive patients (23 ears) implanted with a cochlear electrode were investigated. The study comprised 19 children (2 bilateral) and 2 adults.

The measured ‘A’ distances (the largest distance from the round window to the contralateral wall) corresponded to cochlear duct lengths of 28.5–36.4 mm. The mean cochlear duct length was 34.05 ± 1.72 mm (33.60 ± 2.27 mm in females and 34.35 ± 1.27 mm in males). Full insertion was achieved in all but two cases. No misplaced electrode array or electrode fold-over was detected. In all but three ears, the electrode was chosen based on the research software application's indication.

The results show a good correlation between the pre-operatively predicted insertion depths using the software application and those post-operatively measured using X-ray. The insertion length predicted by the software was always longer than that measured via X-ray.

Conductive hyperacusis in superior semicircular canal dehiscence syndrome occurs due to the presence of a ‘third window’ created by the dehiscence. Reversible blocking of the round window can, in theory, cause a reduction in the compression-related volume displacement, and thereby minimise symptoms of conductive hyperacusis. This study describes a technique of permeatal blocking of the round window.

The tympanomeatal flap is elevated and the round window niche is identified. The round window membrane is subsequently identified and occluded with bone wax, muscle and fascia, in three separate layers. Finally, the tympanomeatal flap is reflected, and an ear wick is inserted.

Two patients who underwent the procedure reported a reduction in symptoms. Importantly, no Tullio phenomenon was reported post-operation.

Blocking of the round window can be used to control symptoms of superior semicircular canal dehiscence syndrome in patients who present solely with symptoms of conductive hyperacusis. This technique provides an alternative to resurfacing techniques. The procedure is simple to perform, reversible and can be undertaken as day-case surgery.