The impact of round window vs cochleostomy surgical approaches on interscalar excursions in the cochlea: Preliminary results from a flat‐panel computed tomography study

Abstract

ObjectiveTo evaluate incidence of interscalar excursions between round window (RW) and cochleostomy approaches for cochlear implant (CI) insertion.MethodsThis was a retrospective case-comparison. Flat-panel CT (FPCT) scans for 8 CI users with Med-El standard length electrode arrays were collected. Surgical technique was identified by a combination of operative notes and FPCT imaging. Four cochleae underwent round window insertion and 4 cochleae underwent cochleostomy approaches anterior and inferior to the round window.ResultsIn our pilot study, cochleostomy approaches were associated with a higher likelihood of interscalar excursion. Within the cochleostomy group, we found 29% of electrode contacts (14 of 48 electrodes) to be outside the scala tympani. On the other hand, 8.5% of the electrode contacts (4 of 47 electrodes) in the round window insertion group were extra-scalar to the scala tympani. These displacements occurred at a mean angle of occurrence of 364° ± 133°, near the apex of the cochlea. Round window electrode displacements tend to localize at angle of occurrences of 400° or greater. Cochleostomy electrodes occurred at an angle of occurrence of 19°–490°.ConclusionsCurrently, the optimal surgical approach for standard CI electrode insertion is highly debated, to a certain extent due to a lack of post-operative assessment of intracochlear electrode contact. Based on our preliminary findings, cochleostomy approach is associated with an increased likelihood of interscalar excursions, and these findings should be further evaluated with future prospective studies.

Transduction Efficiency and Immunogenicity of Viral Vectors for Cochlear Gene Therapy: A Systematic Review of Preclinical Animal Studies

“…Cochleostomy can be used for both delivery in endolymph or perilymph and shows transduction patterns similar to the RWM. However, several studies have indicated that the risk of surgical trauma is slightly increased in cochleostomy compared to RWM (Chien et al, 2015 ; Jiam and Limb, 2016 ). Cochleostomy resulted in successful transgene expression in HCs, SCs and SGNs.…”

A maradványhallás megőrzésének lehetőségei cochlearis implantáció során Nucleus CI532 Slim Modiolar elektródasorral

“…Az elektródaprofilok modiolustól való távolságuk alapján (A) perimodiolaris, (B) mid-scala, (C) "lateral-wall" típusba sorolhatók. A jelen cikk tárgyát képező Nucleus CI532-es elektróda a perimodiolaris csoport tagja [11]. A csont szükséges mértékű elfúrásához minden esetben 1 mm átmérőjű gyémántfúrót használunk lassú fordulatszámon, ezzel elkerülve a fúrás során keletkező hang-és hőártalmat [13,14].…”

“…A hallási teljesítmény maximalizálása ugyanis a beillesztési trauma minimalizálásától függ [8]. Cochlearis implantáció során károsodhatnak az endocochlearis struktúrák, melyek azonnali vagy akár késői posztoperatív residualishallás-romlás forrásai lehetnek [9][10][11]. Az elektródasor bevezetése során esetlegesen kialakuló belsőfül-trauma az eredete alapján, sebészi szempontból, két csoportba sorolható.…”

Real-Time Data-Driven Approach for Prediction and Correction of Electrode Array Trajectory in Cochlear Implantation

“…The process of atraumatic insertion possesses several challenges: the size of cochlea/ST, position of facial nerve with respect to cochlea opening, the insertion axis, and associated trajectory and inconsistency of mental representation of insertion axis among surgeons. Preserving the internal tissue structures during insertion, such as basilar membrane, osseous lamina, and spiral ligament, are fundamentally important for better hearing perception post-surgery [6,7]. Translocation of EA from ST to scala media (SM) or scala vestibuli (SV) is a major cause of residual hearing loss that can to lead poor CI performance throughout a patient's life [8].…”