Surgical outcomes of simultaneous cochlear implantation with subtotal petrosectomy

Cochlear implant positioning: development and validation of an automatic method using computed tomography image analysis

The aim of this study was to preoperatively asses the feasibility of drilling a bony recess for the fixation of a cochlear implant in the temporal bone. Even though complications are rare with cochlear implantations, drilling at the site of implantation have resulted in hematoma or cerebrospinal fluid leakage. Mainly in cases with a reduced temporal bone thickness, the risk for complications has increased, such as in paediatric patients.

Methods

An in-house designed semi-automatic algorithm was developed to analyse a 3D model of the skull. The feasibility of drilling the recess was determined by a gradient descent method to search for the thickest part of the temporal bone. Feasibility was determined by the residual bone thickness which was calculated after a simulated drilling of the recess at the thickest position. An initial validation of the algorithm was performed by measuring the accuracy of the algorithm on five 3D models with known thickest locations for the recess. The accuracy was determined by a part comparison between the known position and algorithm provided position.

Results

In four of the five validation models a standard deviation for accuracy below the predetermined cut-off value of 4.2 mm was achieved between the actual thickest position and the position determined by the algorithm. Furthermore, the residual thickness calculated by the algorithm showed a high agreement (max. 0.02 mm difference) with the actual thickness.

Conclusion

With the developed algorithm, a semi-automatic method was created to analyse the temporal bone thickness within a specified region of interest on the skull. Thereby, providing indications for surgical feasibility, potential risks for anatomical structures and impact on procedure time of cochlear implantation. This method could be a valuable research tool to objectively assess feasibility of drilling a recess in patients with thin temporal bones preoperatively.

A monocenter, patient-blinded, randomized, parallel-group, non-inferiority study to compare cochlear implant receiver/stimulator device fixation techniques (COMFIT) with and without drilling in adults eligible for primary cochlear implantation

BACKGROUND

During the cochlear implantation procedure, the receiver/stimulator (R/S) part of the implant is fixated to prevent postoperative device migration, which could have an adverse effect on the position of the electrode array in the cochlea. We aim to compare the migration rates of two fixation techniques, the bony recess versus the subperiosteal tight pocket without bony sutures.

METHODS AND ANALYSIS

This single-blind randomized controlled trial will recruit a total of 112 primary cochlear implantation adult patients, eligible for implantation according to the current standard of practice. Randomization will be performed by an electronic data capture system Castor EDC, with participants block randomized to either bony recess or standard subperiosteal tight pocket in a 1:1 ratio, stratified by age. The primary outcome of this study is the R/S device migration rate; secondary outcomes include patient-experienced burden using the validated COMPASS questionnaire, electrode migration rate, electrode impedance values, speech perception scores, correlation between R/S migration, electrode array migration and patient complaints, assessment of complication rates, and validation of an implant position measurement method. Data will be collected at baseline, 1 week, 4 weeks, 8 weeks, 3 months, and 12 months after surgery. All data analyses will be conducted according to the intention-to-treat principle.

DISCUSSION

Cochlear implantation by means of creating a tight subperiosteal pocket without drilling a bony seat is a minimally invasive fixation technique with many advantages. However, the safety of this technique has not yet been proven with certainty. This is the first randomized controlled trial that directly compares the minimally invasive technique with the conventional method of drilling a bony seat.

TRIAL REGISTRATION

Netherlands Trial Register NL9698. Registered on 31 August 2021.

Current trends on subtotal petrosectomy with cochlear implantation in recalcitrant chronic middle ear disorders

Objective

To establish the safety and effectiveness of subtotal petrosectomy with cochlear implantation in patients affected by chronic middle ear disorders to refractory to previous surgical treatments.

Methods

A multicentre, retrospective study was conducted on patients affected by recalcitrant chronic middle ear disorders who underwent cochlear implantation in combination with subtotal petrosectomy. Patients' details were collected from databases of 11 Italian tertiary referral centres. Additionally, a review of the most updated literature was carried out.

Results

55 patients were included with a mean follow-up time of 44 months. Cholesteatoma was the most common middle ear recurrent pathology and 50.9% of patients had an open cavity. 80% of patients underwent a single stage surgery. One case of explantation for device failure was reported among the 7 patients with post-operative complications.

Conclusions

Subtotal petrosectomy with cochlear implantation is a benchmark for management of patients with recalcitrant chronic middle ear disorders. A single stage procedure is the most recommended strategy. Optimal follow-up is still debated. Further studies are required to investigate the role of this surgery in paediatric patients.

Subtotal Petrosectomy and Cochlear Implantation in Children With Chronic Suppurative Otitis Media: A Single Institutional Experience

BACKGROUND AND OBJECTIVES

Chronic suppurative otitis media (CSOM) with or without cholesteatoma is a frequent chronic inflammatory condition in children, which may lead to severe hearing loss that affects speech development. Treatment of recurrent CSOM associated with unserviceable hearing requires a specialized approach with regard to disease eradication and hearing rehabilitation. In this study, we investigated the advantages of subtotal petrosectomy (SP) combined with cochlear implantation (CI) in children with CSOM associated with unserviceable hearing and describe our experience with regard to the efficacy of this method, together with a literature review.

SUBJECTS AND METHODS

SP with sequential or simultaneous CI was performed in three children (four ears), and postoperative audiometric data were recorded.

RESULTS

The study included two male and one female patient. Mean age at the time of SP was 10.75 years (7-13 years). Sequential implantation was performed in three ears. Facial nerve palsy occurred after SP in one patient. The latest word recognition scores of Cases 1, 2, and 3 were 80% (at 60 dB), 75% (at 60 dB), and 70% (at 50 dB) and 90% (at 50 dB), respectively.

CONCLUSIONS

SP with CI may be safe and reliable in children with CSOM associated with unserviceable hearing.

Subtotal Petrosectomy (SP) in Cochlear Implantation (CI): A Report of 92 Cases

In most cases, cochlear implantation is a straightforward procedure. Nevertheless, there are clinical situations in which the presence of the middle ear may compromise access and/or the outcome in terms of complications. This article includes a series of patients for whom we eliminated the middle ear to facilitate placement of the electrode array of the implant and/or reduce potential complications. A total of 92 cases in 83 patients, managed by the senior author, are included in this series. Different indications are outlined that justify associating a subtotal petrosectomy technique with cochlear implantation. The steps of the technique are described. We include complications from this series that compare favorably with standard techniques.