Preoperative evaluation of cochlear implantation through the round window membrane in the facial recess using high-resolution computed tomography

Xie, Lihong; Tang, Jie; Miao, Wenjie; Tang, Xianglong; Tang, Anzhou

doi:10.1007/s00276-018-1972-x

Cited by 16 publications

(10 citation statements)

References 13 publications

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“…Other causes that can obscure the RWM visibility have been described in previous studies, such as a 'high riding' jugular bulb or an overhanging posterior canal wall (Hamamoto, Murakami, & Kataura, 2000;Kashio et al, 2015;Xie et al, 2018). In this study, there was one case with an overhanging posterior wall, and one with a high riding jugular bulb.…”

Section: Operative Reportsupporting

confidence: 56%

Structure and hearing preservation in cochlear implant surgery

Jwair¹

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Preserving cochlear structures during cochlear implantation is considered one of the most important steps in improving the hearing performance of CI patients. Minimizing trauma to the cochlea, i.e. preserving the residual hearing, allows for better speech perception performance by the added benefits of acoustical stimulation to the electrical hearing with CI, and probably overall better electrical hearing due to deaccelerated degeneration of the auditory nerve. The differences between PM and LW arrays regarding structure preservation are substantial, and should be carefully considered before commencing cochlear implantation, especially in patients with (substantial) residual hearing. STL and TF of the array can cause severe intracochlear trauma by piercing the cochlear partition, and it impacts speech perception and the residual hearing of CI recipients. STL and TF were primarily associated with PM arrays. However, studies with CI recipients had a substantial risk of bias, mainly caused by lack of randomization, and lack of standardization of insertion approaches (i.e. RW and CO). Subsequent research with human cadaveric temporal bones showed that the interaction between array type and surgical approach is an important factor regarding insertion trauma. Research showed that scalar localization of LW arrays on CT scans is difficult to interpret, due to LW arrays translocating not only towards SV but also to SM. Therefore, LW array STL rates are probably underestimated in literature. Additionally, PM arrays have in general more efficient stimulation of the auditory nerve than LW arrays, potentially improving speech perception, and lowering battery consumptions. Currently it is not clear which aspect, the preserved cochlear structure or more efficient auditory nerve stimulation, is more important for CI recipients, and how this relates to the surgical approach. This notion should be tested in the clinical practice, particularly the consequences for preservation of residual hearing and hearing with CI in general including speech perception. Although the osseous spiral lamina and basilar membrane are not visible on CT scans, accurate assessment of scalar position is possible for both type of arrays if using an adaption of curved multiplanar reconstruction method (i.e. uncoiled cochlear duct). Lastly, ECochG during several stages of the cochlear implantation procedure showed that acute basal turn trauma in the form of cochleostomy and subsequent short array insertion can affect the apical region of the cochlea.

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Section: Operative Reportsupporting

confidence: 56%

Structure and hearing preservation in cochlear implant surgery

Jwair¹

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“…Other causes that can obscure the RWM visibility have been described in previous studies, such as a ‘high riding’ jugular bulb or an overhanging posterior canal wall [ 6 , 12 , 16 , 17 ]. In this study, there was one case with an overhanging posterior wall, and one with a high riding jugular bulb.…”

Section: Discussionmentioning

confidence: 97%

Radiological and surgical aspects of round window visibility during cochlear implantation: a retrospective analysis

Jwair

Eijden

Blijleven

et al. 2021

Eur Arch Otorhinolaryngol

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Purpose The round window approach has become the most preferred option for cochlear implant (CI) insertion, however, sometimes it may not be possible due to the (in)visibility of the round window membrane (RWM). We addressed the prevalence, consequences and indicators of difficult detection of the RWM in cochlear implant surgery. Methods This study retrospectively analysed the operative reports and preoperative high resolution axial-computed tomography (CT) scans of a consecutive cohort of patients who underwent a CI insertion. The main outcomes were surgical outcomes of the RW approach, and assessment of radiological markers. Results The operative reports showed that RWM insertion was feasible in 151 out of 153 patients. In 18% of the patients the RWM was difficult to visualize. All these patients had at least one intraoperative event. The chorda tympani nerve (CTN) or posterior canal wall was affected in 8% of the 153 patients and the fallopian canal in 6%. These patients had a facial-chorda tympani nerve distance on the CT scan that was considerably smaller than normal patients (1.5 mm vs 2.3 mm). In addition, a prediction line towards the anterolateral side of the RWM was found to be more prevalent in these patients’ CT scans (sensitivity 81%, specificity 63%). Conclusion The RW approach is feasible in almost all patients undergoing CI surgery. Difficult visualisation of the RWM seems to lead to at least one intraoperative event. Radiological measures showed that these patients had a smaller facial recess and a more anteriorly placed facial nerve, which can be used to better plan a safe insertion approach.

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“…The electrodes of all patients in this study were inserted through the round window approach. The difficulty of electrode implantation through the round window is dependent on the patient’s anatomy; a larger angle between the line connecting the leading edge of the facial nerve to the midpoint of the round window and the median sagittal line, which can be measured in preoperative CT scans, is associated with a greater difficulty in round window implantation [ 17 ]. Poor mastoid aeration and lower position of the tegmen are also associated with higher difficulty in accessing the round window [ 18 ].…”

Section: Discussionmentioning

confidence: 99%

New hybrid multiplanar cone beam computed tomography-laser-fluoroscopic-guided approach in cochlear implant surgery

et al. 2022

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Purpose Cochlea implant surgery with proper positioning of the cochlear electrode can be challenging. Intraoperative real-time hybrid laser-fluoroscopic-guided navigation based on a multiplanar cone beam computed tomography (CBCT) dataset opens up the opportunity to immediate radiological control of primary electrode misalignments and offering new insights into the cochlea electrode insertion routes and favorable cochlear implant-insertion angle. Methods In this retrospective study, 50 cases (29 males, 18 females) of conventional electrode implantation (without intraoperative image control; group A) and nine cases (7 males, 2 females) of CBCT-laser-fluoroscopic-guided surgery (group B) were included in the present study. CBCT-laser-guided surgery under real-time fluoroscopic control was conducted using an intraoperative C-arm CBCT. All patients received preoperative cross-sectional imaging (CT and MRI), in which cochlear malformation could be excluded. Postoperatively, we looked for electrode misplacements. Results In group A, electrode misalignment was detected postoperatively in 14 of 50 cases (28.0%). In group B, primary electrode misalignment was detected intraoperatively in two patients (22.2%). In both patients, the misalignments were corrected in the same session. The comparison of cochlear insertion angles showed significant differences. Group A: 47.5 ± 2.6° (actual conventional surgery) vs 17.6 ± 2.8° (theoretical CBCT-laser-fluoroscopic-guided surgery) P < 0.001. Group A vs group B: 47.5 ± 2.6° (actual conventional surgery; Group A) vs 17.9 ± 2.5° (actual CBCT-laser-fluoroscopic-guided surgery; Group B) P < 0.001. Conclusion We consider that an intraoperative hybrid CBCT-laser-fluoroscopic-controlled approach in cochlear implant surgery using a C-arm CT can be beneficial, because electrode misalignments can be reduced and if it does occur, remedied in the same surgical session.

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Preoperative evaluation of cochlear implantation through the round window membrane in the facial recess using high-resolution computed tomography

Cited by 16 publications

References 13 publications

Structure and hearing preservation in cochlear implant surgery

Structure and hearing preservation in cochlear implant surgery

Radiological and surgical aspects of round window visibility during cochlear implantation: a retrospective analysis

New hybrid multiplanar cone beam computed tomography-laser-fluoroscopic-guided approach in cochlear implant surgery

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