title: Insertion trauma of a cochlear implant electrode array with Nitinol inlay.
abstract: The integration of a shape memory actuator is a potential mechanism to achieve a consistent perimodiolar position after electrode insertion during cochlear implant surgery. After warming up, and therefore activation of the shape memory effect, the electrode array will change from a straight configuration into a spiral shaped one leading to a final position close to the modiolus. The aim of this study was to investigate whether the integration of an additional thin wire (referred to as an "inlay") made of Nitinol, a well-established shape memory alloy, in a conventional hearing preservation electrode array will affect the insertion behaviour in terms of increased risk of insertion trauma. Six conventional Hybrid-L electrode arrays (Cochlear Ltd., Sydney, Australia) were modified to incorporate a wire inlay made of Nitinol. The diameter of the wires was 100 µm with a tapered tip region. Electrodes were inserted into human temporal bone specimens using a standard surgical approach. After insertion and embedding in epoxy resin, histological sections were prepared to evaluate insertion trauma. Insertion was straightforward and no difficulties were observed. The addition of a shape memory wire, thin but also strong enough to curl the electrode array, does not result in histologically detectable insertion trauma. Atraumatic insertion seems possible.
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany. rau.thomas@mh-hannover.de.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Rau
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Lenka
authors.initials: L
authors.lastname: Harbach
authors.affiliation: Cochlear Limited, 1 University Avenue, Macquarie University, Sydney, NSW, 2109, Australia.
authors.forename: Nick
authors.initials: N
authors.lastname: Pawsey
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Marcel
authors.initials: M
authors.lastname: Kluge
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Erfurt
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.|Cluster of Excellence Hearing4all, Hannover Medical School, Hannover, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenarz
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.|Cluster of Excellence Hearing4all, Hannover Medical School, Hannover, Germany.
authors.forename: Omid
authors.initials: O
authors.lastname: Majdani
mesh_terms: D000497:Alloys; D002102:Cadaver; D019929:Cochlear Implantation / Q000009:adverse effects / Q000379:methods*; D003054:Cochlear Implants; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology / Q000517:prevention & control; D011474:Prosthesis Design; D013701:Temporal Bone / Q000601:surgery*
chemical_list: D000497:Alloys; C013616:nitinol
keywords: Cochlear implant; Insertion study; Nitinol; Perimodiolar; Shape memory; Temporal bone; Trauma