scholarly journals Hydraulic insertions of cochlear implant electrode arrays into the human cadaver cochlea: preliminary findings

Author(s):  
M. Geraldine ◽  
Thomas Lenarz ◽  
Thomas S. Rau

Abstract Objectives (1) To evaluate the feasibility of a non-invasive, novel, simple insertion tool to perform automated, slow insertions of cochlear implant electrode arrays (EA) into a human cadaver cochlea; (2) to estimate the handling time required by our tool. Methods Basic science study conducted in an experimental OR. Two previously anonymized human cadaver heads, three commercially available EAs, and our novel insertion tool were used for the experiments. Our tool operates as a hydraulic actuator that delivers an EA at continuous velocities slower than manually feasible. Intervention(s): the human cadaver heads were prepared with a round-window approach for CI surgery in a standard fashion. Twelve EA insertion trials using our tool involved: non-invasive fixation of the tool to the head; directing the tool to the round window and EA mounting onto the tool; automated EA insertion at approximately 0.1 mm/s driven by hydraulic actuation. Outcome measurement(s): handling time of the tool; post-insertion cone-beam CT scans to provide intracochlear evaluation of the EA insertions. Results Our insertion tool successfully inserted an EA into the human cadaver cochlea (n = 12) while being attached to the human cadaver head in a non-invasive fashion. Median time to set up the tool was 8.8 (7.2–9.4) min. Conclusion The first insertions into the human cochlea using our novel, simple insertion tool were successful without the need for invasive fixation. The tool requires < 10 min to set up, which is clinically acceptable. Future assessment of intracochlear trauma is needed to support its safety profile for clinical translation.

2014 ◽  
Vol 8 (4) ◽  
Author(s):  
Lisandro Leon ◽  
Matt S. Cavilla ◽  
Michael B. Doran ◽  
Frank M. Warren ◽  
Jake J. Abbott

Experiments with scala-tympani (ST) phantoms are used to evaluate new electrode arrays and cochlear-implant insertion techniques. To date, phantoms have not accounted for clinical orientations and geometric differences between round-window (RW) insertions and anteroinferior cochleostomy insertions. For improved assessments of insertion experiments, we present a scala-tympani phantom that offers three distinct benefits over previous phantoms: it mimics the standard otologic position, it accommodates for both round-window and anteroinferior cochleostomy insertions, and it incorporates a visual coordinate system based on industry consensus making standardized angular measurements possible.


2010 ◽  
Vol 130 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Omid Majdani ◽  
Daniel Schurzig ◽  
Andreas Hussong ◽  
Thomas Rau ◽  
Justin Wittkopf ◽  
...  

2009 ◽  
pp. 1-6 ◽  
Author(s):  
Omid Majdani ◽  
Daniel Schurzig ◽  
Andreas Hussong ◽  
Thomas Rau ◽  
Justin Wittkopf ◽  
...  

2020 ◽  
Vol 15 (11) ◽  
pp. 1931-1939
Author(s):  
Thomas S. Rau ◽  
M. Geraldine Zuniga ◽  
Rolf Salcher ◽  
Thomas Lenarz

Abstract Purpose Automated insertion of electrode arrays (EA) in cochlear implant surgery is presumed to be less traumatic than manual insertions, but no tool is widely available in the operating room. We sought (1) to design and create a simple tool able to automate the EA insertion process; and (2) to perform preliminary evaluations of the designed prototype. Methods A first prototype of a tool with maximum simplicity was designed and fabricated to take advantage of hydraulic actuation. The prototype facilitates automated forward motion using a syringe connected to an infusion pump. Initial prototype evaluation included: (1) testing of forward motion at different velocities (2) EA insertion trials into an artificial cochlear model with force recordings, and (3) evaluation of device handling, fixation and positioning using cadaver head specimens and a surgical retractor. Alignment of the tool was explored with CT imaging. Results In this initial phase, the prototype demonstrated easy assembly and ability to respond to hydraulic actuation driven by an infusion pump at different velocities. EA insertions at an ultra-slow velocity of 0.03 mm/s revealed smooth force profiles with mean maximum force of 0.060 N ± 0.007 N. Device positioning with an appropriate insertion axis into the cochlea was deemed feasible and easy to achieve. Conclusions Initial testing of our hydraulic insertion tool did not reveal any serious complications that contradict the initially defined design specifications. Further meticulous testing is needed to determine the safety of the device, its reliability and clinical applicability.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Graziela de Souza Queiroz Martins ◽  
Rubens Vuono Brito Neto ◽  
Robinson Koji Tsuji ◽  
Eloisa Maria Mello Santiago Gebrim ◽  
Ricardo Ferreira Bento

Hypothesis. This study aimed to evaluate whether there is a difference in the degree of intracochlear trauma when the cochlear implant electrode arrays is inserted through different quadrants of the round window membrane.Background. The benefits of residual hearing preservation in cochlear implant recipients have promoted the development of atraumatic surgeries. Minimal trauma during electrode insertion is crucial for residual hearing preservation.Methods. In total, 25 fresh human temporal bones were subjected to mastoidectomy and posterior tympanotomy. The cochlear implant electrode array was inserted through the anterosuperior quadrant of the round window membrane in 50% of the bones and through the anteroinferior quadrant in the remaining 50%. The temporal bones were dehydrated, embedded in epoxy, serially polished, stained, viewed through a stereomicroscope, and photographed with the electrode arraysin situ. The resulting images were analyzed for signs of intracochlear trauma.Results. Histological examinations revealed varying degrees of damage to the intracochlear structures, although the incidence and severity of intracochlear trauma were not influenced by the quadrant of insertion.Conclusions. The incidence and severity of intracochlear trauma were similar in all samples, irrespective of electrode array insertion through the anterosuperior or anteroinferior quadrant of the round window membrane.


2021 ◽  
pp. 014556132199018
Author(s):  
Murat Koc ◽  
Abdullah Dalgic ◽  
Mehmet Ziya Ozuer

Objective: To investigate the effects of the mechanical trauma to the round window, a model electrode inserted into the scala tympani on the cochlear reserve, and the efficacy of topical steroids in preventing hearing loss. Materials and Methods: 21 male Wistar Albino rats were equally categorized into three groups. In all groups an initial mechanical injury to round window was created. Only subsequent dexamethasone injection was administrated into the cochlea in the subjects of group 2 while a multichannel cochlear implant guide inserted into the cochlea prior to dexamethasone administration for group 3. Distortion product otoacoustic emissions (DPOAEs) were obtained prior to and immediately after the surgical injury, eventually on postoperative seventh day (d 7). Mean signal/noise ratios (S/Ns) obtained at 2000, 3000, and 4000 Hz were calculated. Data sets were compared with non-parametric statistical tests. Results: The early intraoperative mean S/Ns were significantly less than preoperative measurements for group 1 and 2; however, preoperative and postoperative d 7 average S/Ns did not differ. There was statistically significant difference between preoperative, intraoperative and postoperative d 7 average S/Ns for group 3. Conclusion: We observed that hearing was restored approximately to the preoperative levels following early postoperative repair. However, an electrode insertion into the cochlea via round window subsequent to mechanical trauma seems to cause a progressive hearing loss. Therefore, a special care must be taken to avoid the injury to the round window membrane in the course of the placement of a cochlear implant electrode and surgery for the chronic otitis media.


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