Figure - available from: BioMed Research International
This content is subject to copyright. Terms and conditions apply.
Incision and electrode array insertion through the anterosuperior quadrant of the round window membrane. (a) Incision in the anterosuperior quadrant of the round window membrane. (b) Beginning of the insertion of the electrode array through the opening in the anterosuperior quadrant.
Source publication
Hypothesis:
This study aimed to evaluate whether there is a difference in the degree of intracochlear trauma when the cochlear implant electrode arrays is inserted through different quadrants of the round window membrane.
Background:
The benefits of residual hearing preservation in cochlear implant recipients have promoted the development of atr...
Similar publications
Tympanomastoid surgery for cholesteatoma is a procedure designed to eliminate the
disease and maintain a safe and dry ear. This retrospective study was designed to
evaluate the functional results of cholesteatoma patients who underwent canal wall
down mastoidectomy in conjunction with a tympanoplasty. Operated ears due to
chronic otitis media with...
Acute mastoiditis (AC) is a serious complication of acute otitis media (AOM) affecting, in most cases, the pediatric population. Diagnosis is usually easy in front of a retro auricular swelling associated to OM. However, this disease may cause significant and even life threatening complications beyond the tympanomastoid system such as peripheral fa...
Objective: To study the prevalence of ear, nose and throat diseases and their possible surgical intervention in local population of Pakistan.
Methodology: 1,382 patients from the department of ear, nose and throat surgery from January-December 2016 were selected in this retrospective study. The age, gender, presenting complains with history, diagno...
Objectives: A high prevalence of untreated surgical disease for hearing loss exists in West Africa. The purpose of this pilot study was to review hearing outcomes after initial implementation of a surgical otology program in a teaching hospital in Ghana. Methods: A retrospective case series of patients who had surgical intervention for chronic supp...
Background: The prevalence of chronic suppurative otitis media (CSOM) is still high in developing countries. According to the World Health Organization (WHO), the prevalence of CSOM is 2-4%. In 1994-1996, the prevalence of CSOM in various provinces in Indonesia is diverse, with general prevalence of 3.9%. Chronic suppurative otitis media can also l...
Citations
... The development of new electrodes in all types of CIs has made remarkable technical progress in the past 30 years [1,2] and is efficacious in children [3] and adults [4]. Despite this progress, electrode insertion is still known to be traumatic for the inner ear, resulting in fibrosis, interstitial proliferation and autoimmune reactions [5][6][7][8][9][10]. ...
Globally, over the next few decades, more than 2.5 billion people will suffer from hearing impairment, including profound hearing loss, and millions could potentially benefit from a cochlea implant. To date, several studies have focused on tissue trauma caused by cochlea implantation. The direct immune reaction in the inner ear after an implantation has not been well studied. Recently, therapeutic hypothermia has been found to positively influence the inflammatory reaction caused by electrode insertion trauma. The present study aimed to evaluate the hypothermic effect on the structure, numbers, function and reactivity of macrophages and microglial cells. Therefore, the distribution and activated forms of macrophages in the cochlea were evaluated in an electrode insertion trauma cochlea culture model in normothermic and mild hypothermic conditions. In 10-day-old mouse cochleae, artificial electrode insertion trauma was inflicted, and then they were cultured for 24 h at 37 °C and 32 °C. The influence of mild hypothermia on macrophages was evaluated using immunostaining of cryosections using antibodies against IBA1, F4/80, CD45 and CD163. A clear influence of mild hypothermia on the distribution of activated and non-activated forms of macrophages and monocytes in the inner ear was observed. Furthermore, these cells were located in the mesenchymal tissue in and around the cochlea, and the activated forms were found in and around the spiral ganglion tissue at 37 °C. Our findings suggest that mild hypothermic treatment has a beneficial effect on immune system activation after electrode insertion trauma.
... First, electrode array insertion was incomplete, with the four basal electrodes outside the cochlea, which corresponds to an insertion depth of 20.5 mm. In comparison, clinical insertions depth for this array ranges from 23 to 25 mm [32,33]. Second, measurements were conducted directly after insertion and without any tissue growth near the cochlear. ...
Oticon Medical cochlear implants use a stimulation mode called Distributed All-Polar (DAP) that connects all non-stimulating available intracochlear electrodes and an extracochlear reference electrode. It results in a complex distribution of current that is yet undescribed. The present study aims at providing a first characterization of this current distribution. A Neuro Zti was modified to allow the measurement of current returning to each electrode during a DAP stimulation and was implanted in an ex-vivo human head. Maps of distributed current were then created for different stimulation conditions with different charge levels. Results show that, on average, about 20% of current returns to the extracochlear reference electrode, while the remaining 80% is distributed between intracochlear electrodes. The position of the stimulating electrode changed this ratio, and about 10% more current to the extracochlear return in case of the first 3 basal electrodes than for apical and mid position electrodes was observed. Increasing the charge level led to small but significant change in the ratio, and about 4% more current to the extracochlear return was measured when increasing the charge level from 11.7 to 70 nC. Further research is needed to show if DAP yields better speech understanding than other stimulation modes.
... A more clinically useful outcome that we evaluated was intraoperative trauma to the cochlea. Minimizing intracochlear trauma is pivotal for residual hearing preservation [36]. Our analysis suggests that the RW approach may lead to less trauma than the C approach ( Table 3). ...
We conducted a systematic review and meta-analysis to compare round window (RW) and cochleostomy (C) surgical approaches for the placement of cochlear implants (CIs). After obtaining the Institutional Review Board (IRB) approval, 213 peer-reviewed articles published between January 1, 2000, and August 1, 2021, comparing RW and C approaches were identified via a search on Google Scholar, Cochrane, and PubMed. The inclusion criteria were articles having an English version and involving only human subjects (cadaveric or alive). Statistical analysis of compiled electrode-to-modiolus distances was performed with two-sample independent t-tests. Live patients were categorized as having complete hearing preservation (<10 dB threshold shift), partial hearing preservation (10-20 dB shift), or minimal hearing preservation (>20 dB shift). Chi-squared testing was used to compare the distribution of hearing preservation categories between surgical approaches. Due to the heterogeneous nature of the data, only summative information was provided on the effects of approaches on trauma, electrical impedance, speech perception, vestibular dysfunction, ease of scala tympani insertion, and scalar shift. A total of 3,797 CI patients were evaluated. The RW approach resulted in a smaller (0.15 mm smaller on average, p<0.05) electrode-to-modiolus distance when compared to the C approach. The RW approach (93.0%) led to statistically better hearing preservation than the C approach (84.3%) (p<0.05). The RW approach was also associated with better outcomes in terms of speech perception, ease of scala tympani insertion, and reduced scalar shift. No difference between approaches was found with regard to trauma, electrical impedance, and vestibular dysfunction. Based on our findings, the RW approach appears to have several benefits compared to the C approach.
... Lastly, the proposed work has used 3 trajectories which may not be representative of several other insertion possibilities. Further investigation needs to be done by incorporating additional trajectory variants, for example, similar to the work by Martins et al. (Martins et al., 2015) where they are accessing trauma when EA is inserted from different round window quadrants. Nonetheless, the proposed work is a step forward towards more accurate predicted implantation which may also have application in other electrode implants. ...
Cochlear Implant provides an electronic substitute for hearing to severely or profoundly deaf patients. However, postoperative hearing outcomes significantly depend on the proper placement of electrode array (EA) into scala tympani (ST) during cochlear implant surgery. Due to limited intra-operative methods to access array placement, the objective of the current study was to evaluate the relationship between EA complex impedance and different insertion trajectories in a plastic ST model. A prototype system was designed to measure bipolar complex impedance (magnitude and phase) and its resistive and reactive components of electrodes. A 3-DoF actuation system was used as an insertion feeder. 137 insertions were performed from 3 different directions at a speed of 0.08 mm/s. Complex impedance data of 8 electrode pairs were sequentially recorded in each experiment. Machine learning algorithms were employed to classify both the full and partial insertion lengths. Support Vector Machine (SVM) gave the highest 97.1% accuracy for full insertion. When a real-time prediction was tested, Shallow Neural Network (SNN) model performed better than other algorithms using partial insertion data. The highest accuracy was found at 86.1% when 4 time samples and 2 apical electrode pairs were used. Direction prediction using partial data has the potential of online control of the insertion feeder for better EA placement. Accessing the position of the electrode array during the insertion has the potential to optimize its intraoperative placement that will result in improved hearing outcomes.
... Hearing and structure preservation protocols have gained more and more attention over the past decade. Electrode array insertion causes direct mechanical and pathophysiological intracochlear trauma (1,2). In rodent whole-organ culture experiments, electrode insertion trauma (EIT) has been connected with the activation of proinflammatory cytokines like interleukin (IL)-1ß, tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), as well as enzymes like inducible nitric oxide synthase (i-NOS) (2). ...
Introduction: Cochlea implants can cause severe trauma leading to intracochlear apoptosis, fibrosis, and eventually to loss of residual hearing. Mild hypothermia has been shown to reduce toxic or mechanical noxious effects, which can result in inflammation and subsequent hearing loss. This paper evaluates the usability of standard surgical otologic rinsing as cooling medium during cochlea implantation as a potential hearing preservation technique.
Material and Methods: Three human temporal bones were prepared following standard mastoidectomy and posterior tympanotomy. Applying a retrocochlear approach leaving the mastoidectomy side intact, temperature probes were placed into the basal turn (n = 4), the middle turn (n = 2), the helicotrema, and the modiolus. Temperature probe positions were visualized by microcomputed tomography (μCT) imaging and manually segmented using Amira® 7.6. Through the posterior tympanotomy, the tympanic cavity was rinsed at 37°C in the control group, at room temperature (in the range between 22 and 24°C), and at iced water conditions. Temperature changes were measured in the preheated temporal bone. In each temperature model, rinsing was done for 20 min at the pre-specified temperatures measured in 0.5-s intervals. At least five repetitions were performed. Data were statistically analyzed using pairwise t-tests with Bonferroni correction.
Results: Steady-state conditions achieved in all three different temperature ranges were compared in periods between 150 and 300 s. Temperature in the inner ear started dropping within the initial 150 s. Temperature probes placed at basal turn, the helicotrema, and middle turn detected statistically significant fall in temperature levels following body temperature rinses. Irrigation at iced conditions lead to the most significant temperature drops. The curves during all measurements remained stable with 37°C rinses.
Conclusion: Therapeutic hypothermia is achieved with standard surgical irrigation fluid, and temperature gradients are seen along the cochlea. Rinsing of 120 s duration results in a therapeutic local hypothermia throughout the cochlea. This otoprotective procedure can be easily realized in clinical practice.
... Complications from cochlear electrode insertion are related to the degree of damage to the organ of Corti located at the basilar membrane and damage of neuronal structures at the spiral lamina [56]. Histological evaluation classifies different grades of electrode-induced trauma: lifting of the basilar membrane (grade 1), damage of the spiral ligament (grade 2), electrode translocation from the scala tympani to the scala vestibuli (grade 3), and fracture of the osseous spiral lamina or modiolus (grade 4) [57]. ...
Abstract Cochlear implants are increasingly used to treat sensorineural hearing disorders in both children and adults. Pre-operative computed tomography and magnetic resonance imaging play a pivotal role in patient selection, to rule out findings that preclude surgery or identify conditions which may have an impact on the surgical procedure. The post-operative position of the electrode array within the cochlea can be reliably identified using cone-beam computed tomography. Recognition of scalar dislocation, cochlear dislocation, electrode fold, and malposition of the electrode array may have important consequences for the patient such as revision surgery or adapted fitting.
... It is feasible that a wider round window opening may permit a different trajectory that allows the surgeon to insert the electrode at a more optimum angle, resulting in decreased contact with the luminal wall and modiolus. Martins et al 16 conducted a study that, by far, best answers this theory. More than describing the electrode path, they went further to determine whether insertion through the different quadrants of the round window will cause differences in the presence and degree of intracochlear trauma. ...
Objectives
This study aims to compare the hearing preservation outcomes in cochlear implant surgery following slit versus full opening of the round window membrane.
Setting
Tertiary referral center.
Study Design
Comparative study.
Subjects and Methods
Seventy patients (mean, 26.3 years; range, 2-69 years) who underwent cochlear implantation via the round window approach were included in the study. Thirty-five subjects were prospectively enrolled for cochlear implantation via the open round window technique between August 2018 and January 2019. Thirty-five patients who underwent cochlear implantation from January 2017 to July 2018 via the slit round window opening, frequency matched by sex and age, were retrospectively enrolled. Pre- and postoperative thresholds were obtained. The percentage of hearing preservation was computed with the HEARRING Network formula and classified into complete, partial, and minimal hearing preservation. The results between the groups were compared and analyzed at 6 months postoperatively.
Results
The rate of complete hearing preservation in the open group was statistically significant ( P = .030) at 71.4% (n = 25) as compared with 45.7% (n = 16) in the slit group.
Conclusions
The widely opened round window may be an optional technique that surgeons can utilize to improve hearing preservation outcomes.
... We also theorize that hearing preservation outcomes are better with the fully opened round window because it allows an angle of insertion that permits an entry path that is not possible with a smaller opening. Most relevant to this is the study by Martins et al. (48). They compared the intracochlear trauma sustained via anterosuperior and anteroinferior quadrant electrode insertion via the round window but found no significant difference. ...
Objectives:
The purpose of this study was to compare the hearing preservation outcomes of patients who received extended versus single-dose steroid therapy in cochlear implant surgery.
Design:
Case-control.
Setting:
Tertiary referral centers in Taiwan from April 2017 to 2019.
Participants:
A total of 70 patients aged 1 to 78 years old (mean = 18.04, standard deviation [SD] = 21.51) who received cochlear implantation via the round window approach were included in the study. Prospectively, 35 cases were enrolled for cochlear implantation with single-dose therapy. Thirty-five controls who underwent cochlear implantation with extended therapy were retrospectively enrolled after frequency matching.
Outcome measures:
The main outcome measure was the rate of hearing preservation. This was calculated based on the HEARRING Network formula and results were categorized as complete, partial, and minimal. Impedances served as secondary outcomes.
Results:
There was no significant difference in the complete hearing preservation rates between the extended and single-dose groups at 6 months postoperatively. Impedances were significantly lower in the extended group after 1 month and 6 months of follow up. When the complete and partial hearing preservation groups were compared, the size of round window opening and speed of insertion were found to be statistically significant.
Conclusions:
Both extended and single-dose therapies result in good hearing preservation in patients who undergo cochlear implantation. However, better impedances can be expected from patients who received extended therapy. A slower speed of insertion and a widely opened round window play a role in hearing preservation.
... Localized cochlear trauma seen as elevation of the OSL was considered as Grade 1 injury as it does not impede the intra-cochlear fluid hemodynamics [18]. The normal ionic gradient and cochlear hemodynamics are disturbed leading to destruction of both neural and hair cells as a result of post-traumatic merge of the endolymph and perilymph [19,20]. So, trans-scalar displacement of electrode contacts was considered as a more advanced degree of inner ear trauma. ...
Purpose
Cochlear implantation (CI) has been extended to involve younger age group with higher incidence of residual hearing which increases the need of minimizing surgical inner ear trauma. Radiological evaluation for electrode position has been studied yet without assessment of inner ear trauma, our objective is radiological evaluation of post cochlear implantation inner ear trauma
Material and methods
20 patients with CI for pre lingual SNHL were included in this study. Cone beam CT (CBCT) was used for evaluation of electrode position and assessment of inner ear trauma. A Neuroradiologist and an implant surgeon analyzed the relation of inserted electrode to the intra-cochlear structures, with introduction of novel radiological grading for inner ear trauma.
Results
The mean major cochlear diameter was 8.9 mm, the mean angular depth of insertion was 406.9944 (SD = 165.0559). Ten patients were with no cochlear trauma (grade 0), three patients were grade 1, two patients were grade 2 and five patients were grade 3 inner ear trauma.
Conclusion
Radiological evaluation for electrode position should extend to involve assessment of inner ear trauma using relation of the implant to cochlear internal structures which could be performed by CBCT with high resolution and least metallic artifacts.
... It is a long (25 mm), thin ( proximal diameter = 0.5 mm; distal diameter = 0.4 mm), flexible, with a smooth surface silicone array carrying 20 micro-machined titanium-iridium electrodes over 24 mm active distance (Fig. 1). This specific design was demonstrated to exhibit low insertion forces compared to former electrode array designs (Nguyen et al. 2012) and is associated to low levels of intracochlear traumas (Martins et al. 2015). ...
Objective: To propose a method for quantitative assessment of the migration of lateral-wall, straight electrode arrays after surgery based on postoperative Cone Beam Computed Tomography (CBCT) images and automated medical image analysis techniques.
Methods: A preliminary study is conducted on 19 implanted ears. For each implantation, two CBCT images are objectively analyzed. Electrode arrays are consistently projected into the same coordinate system in order to estimate precisely the migration of each electrode. Spatial configuration changes are characterized with the overall curvature of the electrode array.
Results: From the samples analyzed no significant electrode migration, extrusion or electrode curvature changes were found. Mean infinitesimal local migration reveals a tendency where apical electrodes tend to move away from the modiolus and basal electrodes away from the round window.
Conclusion: CBCT images demonstrate adequate resolution with limited artifacts to assess the electrode array position in vivo. Automated medical image analysis techniques and consistent coordinate system allow to quantitatively estimate migration and extrusion effect for lateral-wall, straight electrode array.
