Pathophysiology of Postoperative Hearing Disorders after Vestibular Schwannoma Resection: Insights from Auditory Brainstem Response and Otoacoustic Emissions.

Background: In order to better understand the pathophysiology of surgically induced hearing loss after vestibular schwannoma (VS) surgery, we postoperatively analyzed the hearing status in a series of patients where hearing was at least partially preserved. Methods: Hearing was assessed through tonal audiometry, speech discrimination score, maximum word recognition score (dissyllabic word lists-MaxIS), otoacoustic emissions (OAEs), and auditory brainstem response (ABR). The magnetic resonance imaging (MRI) tumor characterization was also noted. Results: In a series of 24 patients operated on for VS over 5 years, depending on the results of this triple hearing exploration, we could identify, after surgery, patients with either a myelin alteration or partial damage to the acoustic fibers, others with a likely partial cochlear ischemia, and some with partial cochlear nerve ischemia. One case with persisting OAEs and no preoperative ABR recovered hearing and ABR after surgery. Long follow-up (73 ± 57 months) revealed a mean hearing loss of 30 ± 20 dB with a drastic drop of MaxIS. MRI revealed only 25% of fundus invasion. Conclusion: a precise analysis of hearing function, not only with classic audiometry but also with ABR and OEAs, allows for a better understanding of hearing damage in VS surgery.

Early detection of pharyngocutaneous fistulae after total laryngectomy by cytokine in drainage: A pilot study (DEFILAC).

BACKGROUND: The determination of cytokines in the postoperative drainage (POD) fluid could be a method for early detection of the development of a pharyngocutaneous fistula (PCF). MATERIALS AND METHODS: We conducted a prospective two-center study involving 28 patients. PODs were collected on Day 1 (D1) and Day 2 (D2) postoperatively for determination of a cytokine panel and cytobacteriological examination. RESULTS: Eleven (39%) patients presented with PCF on average 13 ± 5.5 days after surgery. Patients with PCF had higher IL-10 (121 vs. 40.3, p = 0.04, effect size (ES) = 0.98 [0.16, 1.79]) and TNFα level (21.2 vs. 2.2, p = 0.02, ES = 0.83 [0.03, 1.63]) on D2. An IL-10 threshold of 72 pg/mL on D2 was diagnostic of the occurrence of PCF with a sensibility of 70%, specificity of 88%. CONCLUSION: The determination of cytokines in POD fluid on D2 is a reliable tool for predicting the development of a PCF after total laryngectomy.

Robotized Cochlear Implantation under Fluoroscopy: A Preliminary Series.

It is known that visual feedback by fluoroscopy can detect electrode array (EA) misrouting within the cochlea while robotized EA-insertion (rob-EAI) permits atraumatic cochlear implantation. We report here our unique experience of both fluoroscopy feedback and rob-EAI in cochlear implant surgery. We retrospectively analyzed a cohort of consecutive patients implanted from November 2021−October 2022 using rob-EAI, with the RobOtol®, to determine the quality of EA-insertion and the additional time required. Twenty-three patients (10 females, 61+/−19 yo) were tentatively implanted using robot assistance, with a rob-EAI speed < 1 mm/s. Only three cases required a successful revised insertion by hand. Under fluoroscopy (n = 11), it was possible to achieve a remote rob-EAI (n = 8), as the surgeon was outside the operative room, behind an anti-radiation screen. No scala translocation occurred. The additional operative time due to robot use was 18+/−7 min with about 4 min more for remote rob-EAI. Basal cochlear turn fibrosis precluded rob-EAI. In conclusion, Rob-EAI can be performed in almost all cases with a low risk of scala translocation, except in the case of partial cochlear obstruction such as fibrosis. Fluoroscopy also permits remote rob-EAI.

Fluoroscopy guided electrode-array insertion for cochlear implantation with straight electrode-arrays: a valuable tool in most cases.

PURPOSE: To highlight the advantages of real time fluoroscopy guided electrode-array (EA) insertion (FGI) during cochlear implants surgery. METHODS: All surgical procedures were performed in a dedicated operating room equipped with a robotic C-arm cone beam device, allowing for intraoperative real time 2D FGI and postoperative 3D imaging. Only straight EAs were used. Patients were sorted out in three groups: ANAT, with anatomical concerns; HP, with residual hearing; NPR: patients with no particular reason for FGI. In all cases the angle of EA-insertion was measured. In the HP group pre and postoperative hearing were compared. The radiation delivered to the patient was recorded. RESULTS: Fifty-three cochlear implantation procedures were achieved under fluoroscopy in 50 patients from November 2015 to January 2020 (HP group: n = 10; ANAT group: n = 13; NPR group: n = 27). In the ANAT group, FGI proved to be helpful in 8 cases (61.5%), successfully guiding the surgeon during EA -insertion. On average, the angle of insertion was at 424° ± 55°. In the HP group, a controlled smooth EA-insertion was carried out in all cases but one. The targeted 360° angle of insertion was always reached. Hearing preservation was possible with an eventual average drop of 30 ± 1.5 dB. In the NPR group, FGI helped control the quality of insertion in all cases and appeared very informative in five (17.8%): one EA-misrouting, three stuck EAs, and one case with hidden electrodes out of the cochlea in revision surgery. Final 3D cone beam CT scan double-checked the EA position in all adults. The radiation dose was equivalent to a bit less than four digital subtract radiographs. CONCLUSION: The FGI is a very useful adjunct in cochlear implantation in all cases of expected surgical pitfalls, in patients with residual hearing, and even in case without preoperative particular reason, with low irradiation.

Pathogenesis of chronic rhinosinusitis with nasal polyps: role of IL-6 in airway epithelial cell dysfunction.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by an alteration in airway epithelial cell functions including barrier function, wound repair mechanisms, mucociliary clearance. The mechanisms leading to epithelial cell dysfunction in nasal polyps (NPs) remain poorly understood. Our hypothesis was that among the inflammatory cytokines involved in NPs, IL-6 could alter epithelial repair mechanisms and mucociliary clearance. The aim of this study was to evaluate the in vitro effects of IL-6 on epithelial repair mechanisms in a wound repair model and on ciliary beating in primary cultures of Human Nasal Epithelial Cells (HNEC). METHODS: Primary cultures of HNEC taken from 38 patients during surgical procedures for CRSwNP were used in an in vitro model of wound healing. Effects of increasing concentrations of IL-6 (1 ng/mL, 10 ng/mL, and 100 ng/mL) and other ILs (IL-5, IL-9, IL-10) on wound closure kinetics were compared to cultures without IL-modulation. After wound closure, the differentiation process was characterized under basal conditions and after IL supplementation using cytokeratin-14, MUC5AC, and ßIV tubulin as immunomarkers of basal, mucus, and ciliated cells, respectively. The ciliated edges of primary cultures were analyzed on IL-6 modulation by digital high-speed video-microscopy to measure: ciliary beating frequency (CBF), ciliary length, relative ciliary density, metachronal wavelength and the ciliary beating efficiency index. RESULTS: Our results showed that: (i) IL-6 accelerated airway wound repair in vitro, with a dose-response effect whereas no effect was observed after other ILs-stimulation. After 24 h, 79% of wounded wells with IL6-100 were fully repaired, vs 46% in the IL6-10 group, 28% in the IL6-1 group and 15% in the control group; (ii) specific migration analyses of closed wound at late repair stage (Day 12) showed IL-6 had the highest migration compared with other ILs (iii) The study of the IL-6 effect on ciliary function showed that CBF and metachronal wave increased but without significant modifications of ciliary density, length of cilia and efficiency index. CONCLUSION: The up-regulated epithelial cell proliferation observed in polyps could be induced by IL-6 in the case of prior epithelial damage. IL-6 could be a major cytokine in NP physiopathology.