Correlation Between NRT and Radiological Measurements in Detection of Position of the Electrode Inside the Cochlea.

Cochlear Function Disorder Clinical Trial

Official title:

Correlation Between the Neural Response Telemetry (NRT) and Radiological Measurements in Detection of Position of the Electrode Inside the Cochlea

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT03306108
• Other study ID #: NRT in Cochlear implantation
• Status: Not yet recruiting
• Phase: N/A
• First received: September 8, 2017
• Last updated: October 9, 2017
• Start date: October 30, 2017
• Est. completion date: November 2018

Study information

• Verified date: September 2017
• Source: Assiut University
• Contact: Samah Hamdy, residant
• Phone: 01067989166
• Email: Samahhamdy92[@]gmail.com
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

The study will be conducted as Prospective study including 50 patients (aged <6years ) at Otorhinolaryngology department, Assuit University Hospital (aged <6years ) who will undergo cochlear implantation. All subjects will undergo implantation with Medel sonata flex 28 or standard electrodes with a standard surgical procedure. The standard surgical procedure will include extended end aural approach ,posterior tympanotomy and a round window insertion.The results of immediate postoperative Neural Response Telemetry (NRT) measurements & postoperative CT imaging will be obtained.

Each patient will be subjected to the following scheme:

• immediate postoperative Neural Response Telemetry (NRT) measurements

• postoperative CT imaging

• Data obtained from both measurements will be used to determine the intra cochlear electrode position then both data will be correlated.

Description:

Cochlear implantation (CI) is a worldwide accepted and effective surgical procedure for patients with profound sensory neural hearing loss to gain near normal hearing.1 The position of electrode inside the cochlea affects the outcomes. Full insertion of the CI electrode array and insertion in scala tympani usually has optimal results and better words recognition.2 Translocation of electrode array from scala tympani to scala vestibule or outword migration of electrode array may result in poor response.2 There are many intraoperative and post operative techniques to determine the position of electrode array inside the cochlea, some are radiological as transorbital view plan x-ray or computed tomography or 3D rotational x ray and others are electrophysiological measurements.3 Although the accuracy of the radiological techinques they are time and cost consuming1. The electrically evoked cochlear action potential (ECAP) threshold is dependent on the distance between the electrodes and the spiral ganglion cells. The neural response telemetry-ratio (NRT-ratio) is one of the electrophysiological measurments techniques and it is based on each individual electrode's ECAP threshold and can identify the intracochlear electrode array position 4. According to a study done by Philipp Mittmann in 2015, a NRT-ratio above 1.05 indicates an electrode translocation from scala tympani to scala vestibuli and a NRT-ratio below 1.05 shows correlation to a pure scala tympani placement5, but another study found variation of the NRT-ratio in a group of patients with an electrode placement within scala tympani.6

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 50
• Est. completion date: November 2018
• Est. primary completion date: October 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 2 Years to 6 Years

Eligibility

Inclusion Criteria:

• patients aged < 6years who will undergo cochlear implantation

Exclusion Criteria:

• Revision cochlear implantation.

• incomplete post-operative electrophysiological measurements.

• unfit patients for surgery

Related Conditions & MeSH terms

• Cochlear Function Disorder
• Hearing Loss, Sensorineural

Intervention

Device:
• NRT
NRTratio is based on each individual electrode's ECAP threshold and can identify the intracochlear electrode array position in perimodiolar electrodes. The NRT-ratio showed a good reliability for the determination of the intracochlear electrode array position compared to the radiologic control intraoperatively Calculation of the NRT-ratio is done by dividing the arithmetic average of the t-NRT values from the apical electrodes 16 to 18 divided by the arithmetic average of the basal t-NRT from electrodes 5 to 7. With a NRT-ratio above 1.05, a high chance of a scalar change was rather likely, and a NRT-ratio below 1.05 was associated with a high chance of an electrode array position within the scala tympani.

Locations

Country	Name	City	State
Egypt	Assiut University Hospital	Assiut

Sponsors (1)

Lead Sponsor	Collaborator
Assiut University

Country where clinical trial is conducted

Egypt, 

References & Publications (3)

Lathuillière M, Merklen F, Piron JP, Sicard M, Villemus F, Menjot de Champfleur N, Venail F, Uziel A, Mondain M. Cone-beam computed tomography in children with cochlear implants: The effect of electrode array position on ECAP. Int J Pediatr Otorhinolaryngol. 2017 Jan;92:27-31. doi: 10.1016/j.ijporl.2016.10.033. Epub 2016 Oct 31. — View Citation

Mittmann P, Todt I, Ernst A, Rademacher G, Mutze S, Göricke S, Schlamann M, Lang S, Arweiler-Harbeck D, Christov F. Radiological and NRT-Ratio-Based Estimation of Slim Straight Cochlear Implant Electrode Positions: A Multicenter Study. Ann Otol Rhinol Laryngol. 2017 Jan;126(1):73-78. Epub 2016 Oct 25. — View Citation

Mittmann P, Todt I, Ernst A, Rademacher G, Mutze S, Göricke S, Schlamann M, Ramalingam R, Lang S, Christov F, Arweiler-Harbeck D. Electrophysiological detection of scalar changing perimodiolar cochlear electrode arrays: a long term follow-up study. Eur Arch Otorhinolaryngol. 2016 Dec;273(12):4251-4256. doi: 10.1007/s00405-016-4175-2. Epub 2016 Jun 28. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Value of Neural Response Telemetry (NRT) & Radiological measurments in evaluation of cochlear implant electrode positions	The study will be conducted as Prospective study including 50 patients (aged <6years ) at Otorhinolaryngology department, Assuit University Hospital (aged <6years ) who will undergo cochlear implantation. All subjects will undergo implantation with Medel sonata flex 28 or standard electrodes with a standard surgical procedure. The standard surgical procedure will include extended end aural approach ,posterior tympanotomy and a round window insertion.The results of immediate postoperative Neural Response Telemetry (NRT) measurements & postoperative CT imaging will be obtained.; Each patient will be subjected to the following scheme: immediate postoperative Neural Response Telemetry (NRT) measurements; postoperative CT imaging; Data obtained from both measurements will be used to determine the intra cochlear electrode position then both data will be correlated.	Baseline