Intraoperative CT-guided cochlear implantation in congenital ear deformity

Intraoperative Handheld Digital X-ray for Assessment of Intracochlear Positioning of Electrode Arrays in Recipients of Cochlear Implants

Objectives: This study aims to evaluate the practicality of handheld digital X-ray in determining the position of the electrode array following Cochlear implantation (CI). Methods: A retrospective study was conducted involving 11 patients (12 ears) who underwent intraoperative imaging via handheld X-ray (MINE ALNU®, OTOM, Gwangju, South Korea) post-CI between December 2021 and January 2023. Immediate confirmation of the correct electrode array placement in the cochlea was achieved, with subsequent comparisons made to C-arm image and postoperative transorbital view X-ray. Results: Rapid intraoperative imaging was achieved in all instances. The electrode types used included 9 Nucleus slim modiolar electrodes, 1 Nucleus contour electrode, and 2 Medel flex26 electrodes. A malpositioned electrode array was detected in one patient. The handheld digital X-ray also adeptly visualized the electrodes implanted in pediatric patients. Conclusions: The use of intraoperative handheld digital X-ray using MINE ALNU® proves to be a safe, efficient, straightforward, and reliable method for immediate identification of an inserted electrode array. It has potential to replace the traditional C-arm X-ray for verifying electrode positioning in the operating room.

Sequential Bilateral Cochlear Implantation in a Child with Severe External, Middle, and Inner Ear Malformations: Surgical Considerations and Practical Aspects

Cochlear implantation (CI) is a safe and beneficial surgery for children with congenital inner ear malformations, with the exception of cochlear nerve aplasia. The combination of microtia with middle and inner ear abnormalities is extremely uncommon and sufficiently severe to make a surgical approach to the cochlea difficult. We report herein the case of a 2-year-old girl who presented with profound bilateral sensorineural hearing loss, congenital aural atresia, microtia, and inner ear malformations. High-resolution computed tomography revealed poor development of the bilateral middle ear spaces, absence of the incus and stapes, aberrant courses of facial nerves, aplastic lateral semicircular canals, and covered round windows. With intraoperative imaging assistance, sequential bilateral CI was performed using a transmastoid approach with no complication. We propose that CI is feasible in patients with severe external and middle ear malformations. However, major malformations increase the risk of complications. As the facial nerve and cochlea are difficult to locate due to the lack of important anatomical landmarks, detailed planning and adequate preparation, including review of the preoperative imaging data, and the use of facial nerve monitoring and intraoperative imaging are very important. In addition, experienced surgeons should perform CI to ensure the success of the operation.

Utility of intraoperative computed tomography for cochlear implantation in patients with difficult anatomy

OBJECTIVE AND IMPORTANCE

To describe cases that illustrate the utility of intraoperative computed tomography (CT) in cochlear implantation of patients with difficult temporal bone anatomy.

CLINICAL PRESENTATION

A 2-year-old male with congenital X-linked stapes gusher syndrome and a 2-year-old female with enlarged vestibular aqueduct underwent successful cochlear implantation with the help of intraoperative CT. In the latter case, the initial intraoperative C-arm fluoroscopy suggested malposition of the electrode, however, was not able to provide details for adjustments. In both cases, intraoperative CT changed the insertion technique of the operating surgeon and allowed for improved electrode positioning. A 47-year-old female with polyostotic fibrous dysplasia and a 55-year-old male with post-meningitis near-total cochlear obliteration underwent successful cochlear implantation with confirmation of electrode position with intraoperative CT. In the former case, the image-guided navigation system was also implemented. Finally, a 72-year-old female underwent cochlear implantation during which intraoperative C-arm fluoroscopy suggested intra-cochlear insertion. However, postoperative CT showed the electrode extending into the internal auditory canal (IAC), illustrating the limitations of C-arm fluoroscopy.

INTERVENTION

Intraoperative CT imaging and image-guided navigation system.

CONCLUSION

When faced with challenging temporal bone anatomy, intraoperative CT can provide critical details of the patient's microanatomy that allows for improved localization of the electrode and adjustments in operative techniques for successful cochlear implantation.

Cochlear Implantation in Inner Ear Malformations: Systematic Review of Speech Perception Outcomes and Intraoperative Findings

Objective

(1) To analyze reported speech perception outcomes in patients with inner ear malformations who undergo cochlear implantation, (2) to review the surgical complications and findings, and (3) to compare the 2 classification systems of Jackler and Sennaroglu.

Data Sources

PubMed, Scopus (including Embase), Medline, and CINAHL Plus.

Review Methods

Fifty-nine articles were included that contained speech perception and/or intraoperative data. Cases were differentiated depending on whether the Jackler or Sennaroglu malformation classification was used. A meta-analysis of proportions examined incidences of complete insertion, gusher, and facial nerve aberrancy. For speech perception data, weighted means and standard deviations were calculated for all malformations for short-, medium-, and long-term follow-up. Speech tests were grouped into 3 categories—closed-set words, open-set words, and open-set sentences—and then compared through a comparison-of-means t test.

Results

Complete insertion was seen in 81.8% of all inner ear malformations (95% CI: 72.6-89.5); gusher was reported in 39.1% of cases (95% CI: 30.3-48.2); and facial nerve anomalies were encountered in 34.4% (95% CI: 20.1-50.3). Significant improvements in average performance were seen for closed- and open-set tests across all malformation types at 12 months postoperatively.

Conclusions

Cochlear implantation outcomes are favorable for those with inner ear malformations from a surgical and speech outcome standpoint. Accurate classification of anatomic malformations, as well as standardization of postimplantation speech outcomes, is necessary to improve understanding of the impact of implantation in this difficult patient population.

Intra-operative skull X-ray for misdirection of the cochlear implant array into the vestibular labyrinth

OBJECTIVES

This paper reports five cases of aberrant cochlear implant electrode array insertion into the vestibular labyrinth. A review of the literature was conducted in order to clarify reasonable preventive and detection strategies and endorse the routine use of intra-operative plain skull X-ray.

METHODS

The study entailed a clinical case series and literature review. The setting was a tertiary academic referral centre. The following data were evaluated: pre-operative temporal bone computed tomography, operative reports, intra-operative imaging, neural response telemetry/imaging and post-operative imaging.

RESULTS

There were no consistent pre-operative risk factors found on computed tomography scans and no reliable intra-operative signs of electrode array misdirection. All misdirections in our case series, and those in the literature, were easily detectable on intra-operative plain film X-ray.

CONCLUSION

These reported cases demonstrate implant misdirection without the surgeon's awareness. Aberrant insertion cannot be anticipated, and neural response telemetry/imaging is not a reliable indicator of misdirection. Routine intra-operative anteroposterior plain X-ray of the head is a reliable indicator of misdirection, and is fast and relatively inexpensive.

Size of the semicircular canals measured by multidetector computed tomography in different age groups

PURPOSE

The purpose of the study was to obtain reference values for the sizes of the semicircular canals (SCCs) on multidetector computed tomographic (CT) images in different age groups.

METHODS

Computed tomographic images of the temporal bone of 210 patients, a total of 420 ears without inner ear pathology, have been evaluated. These patients were divided into 4 groups by age: young children (<7 years), older children and adolescents (8-17 years), adults (18-59 years), and the elderly patients (>60 years). The inner diameter, maximum height, and width of the SCCs were measured.

RESULTS

There was no significant difference in the size of SCC among the 4 age groups. The inner diameter measurements of the anterior SCC, lateral SCC, and posterior SCC were 0.101 ± 0.016, 0.135 ± 0.033, and 0.124 ± 0.021 cm, respectively. The height measurements of the anterior SCC, lateral SCC, and posterior SCC were 0.535 ± 0.086, 0.349 ± 0.090, and 0.490 ± 0.109 cm, respectively. The width measurements of the anterior SCC, lateral SCC, and posterior SCC were 0.567 ± 0.080, 0.302 ± 0.082, and 0.472 ± 0.099 cm, respectively.

CONCLUSIONS

The size of SCCs remains constant from children to the elderly people, unlike the other human organs. The reference values provided by multidetector CT can serve as an aid for the interpretation of CT images.

Surgery of the ear and the lateral skull base: pitfalls and complications

Surgery of the ear and the lateral skull base is a fascinating, yet challenging field in otorhinolaryngology. A thorough knowledge of the associated complications and pitfalls is indispensable for the surgeon, not only to provide the best possible care to his patients, but also to further improve his surgical skills. Following a summary about general aspects in pre-, intra-and postoperative care of patients with disorders of the ear/lateral skull base, this article covers the most common pitfalls and complications in stapes surgery, cochlear implantation and surgery of vestibular schwannomas and jugulotympanal paragangliomas. Based on these exemplary procedures, basic "dos and don'ts" of skull base surgery are explained, which the reader can easily transfer to other disorders. Special emphasis is laid on functional aspects, such as hearing, balance and facial nerve function. Furthermore, the topics of infection, bleeding, skull base defects, quality of life and indication for revision surgery are discussed. An open communication about complications and pitfalls in ear/lateral skull base surgery among surgeons is a prerequisite for the further advancement of this fascinating field in ENT surgery. This article is meant to be a contribution to this process.