The role of cochlear implant positioning on MR imaging quality: a preclinical in vivo study with a novel implant magnet system.

PURPOSES: To investigate the effects for Ultra 3D cochlear implant (CI) positioning on MR imaging quality, looking at a comprehensive description of intracranial structures in cases of unilateral and bilateral CI placement. METHODS: Four CI angular positions (90°, 120°, 135° and 160°) at 9 cm distance from the outer-ear canal were explored. The 1.5 T MRI assessment included our institutional protocol for the investigation of brain pathologies without gadolinium application. Three investigators (two experienced neuroradiologists and one experienced otoneurosurgeon) independently evaluated the MR findings. A 4-point scale was adopted to describe 14 intracranial structures and to determine which CI positioning allowed the best image quality score and how bilateral CI placement modified MRI scan visibility. RESULTS: A high positive correlation was found between the three blinded observers. Structures situated contralateral from the CI showed high-quality values in all four placements. Structures situated ipsilaterally provided results suitable for diagnostic purposes for at least one position. At 90°, artifacts mainly involved brain structures located cranially and anteriorly (e.g., temporal lobe); on the contrary, at 160°, artifacts mostly influenced the posterior fossa structures (e.g., occipital lobe). For the bilateral CI condition, MR imaging examination revealed additional artifacts involving all structures located close to either CI, where there was a signal void/distortion area. CONCLUSIONS: Suitable unilateral CI positioning can allow the visualization of intracranial structures with sufficient visibility for diagnostic purposes. Bilateral CI positioning significantly deteriorates the anatomical visibility. CI positioning might play a crucial role for patients who need post-operative MRI surveillance.

Retrosigmoidal placement of an active transcutaneous bone conduction implant: surgical and audiological perspectives in a multicentre study.

INTRODUCTION: The retrosigmoidal (RS) placement of the Bonebridge system (BB) has been advocated for cases of unfavourable anatomical or clinical conditions which contraindicate transmastoid-presigmoidal positioning. However, these disadvantageous conditions, combined with the considerable dimensions of the implant, may represent a challenge, especially for surgeons with no skull base experience. Moreover, the literature reports only limited experience concerning RS implantation of the BB system. METHODS: A multicentre, retrospective study was conducted to analyse the surgical and functional outcomes of a wide population of patients undergoing RS placement of the BB system by means of a surgical technique specifically developed to overcome the intraoperative issues related to this surgery. Twenty patients with conductive or mixed hearing loss and single sided deafness were submitted to RS implantation of the BB system. RESULTS: Audiological assessment concerning the measurement of the functional and effective gain by pure-tone audiometry (28 dB HL and -12.25 dB HL, respectively) and speech audiometry (24.7 dB HL and -21 dB HL, respectively) was conducted. A high overall subjective improvement of quality of life was recorded with the Glasgow Benefit Inventory questionnaire. No major complications, such as device extrusions or other conditions requiring revision surgery, were reported during the follow-up period (median: 42 months). CONCLUSIONS: In our study, which has one of the largest cohort of patients reported in the literature, RS placement of the BB system was safe and effective. Our functional results showed comparable hearing outcomes with presigmoidal placement. The effective gain, rarely investigated in this field, may be the object of further research to improve our understanding of bone conduction mechanisms exploited by bone conduction hearing implants.

Surgical tracheotomy in COVID-19 patients: an Italian single centre experience.

PURPOSE: Coronavirus infection disease 2019 (COVID-19) causes in 10% of patients a severe respiratory distress syndrome managed with invasive mechanical ventilation (IMV), sometimes difficult to wean. The role of tracheotomy is debated for the possible risks for patients and staff. We are going to describe here our experience with surgical tracheotomy in COVID-19 positive patients. METHODS: We enrolled all intensive care unit (ICU) patients requiring longer than 10 days of IMV. Demographic, clinical, respiratory, complications, and outcomes data were collected, in a particular length of weaning from sedation and IMV, in-ICU and in-hospital mortality rate. All healthcare operators involved were tested for SARS-CoV2 by pharyngeal swab and blood test (antibody test). RESULTS: 13 out of 68 ICU patients (19.1%) underwent surgical tracheotomy after a median intubation period of 14 days. The mean age was 60 (56-65) years. 85% were male patients. Postoperative mild bleeding was seen in 30.7%, pneumothorax in 7.7%. Mean weaning from sedation required 3 days, 19 days from IMV. In-ICU and in-hospital COVID-infection-related mortality was 23.1% and 30.7%, respectively. None of the healthcare operators was found SARS-CoV2 positive during the period of the study. CONCLUSIONS: In COVID-19 pandemic surgical tracheotomy enables to wean from sedation and subsequently from IMV in a safe way for both patients and personnel.

MRI-induced artifact by a cochlear implant with a novel magnet system: an experimental cadaver study.

PURPOSES: To primarily evaluate MRI-induced effects for Ultra 3D cochlear implantation in human cadavers in terms of artifact generation and MR image quality. METHODS: Three human cadaveric heads were submitted to imaging after unilateral and bilateral cochlear implantation. The 1.5 T MR examination protocol was chosen in accordance with our institutional protocol for the assessment of brain pathology. The maximal signal void size was measured according to each sequence and plane. Two experienced neuro-radiologists and one experienced otoneurosurgeon independently evaluated the MR image quality findings. A 4-point scale was used to describe the diagnostic usefulness of 14 brain structures. RESULTS: Shape and size of the artifacts were found to be highly related to MRI sequences and acquisition planes. MRI sequences and processing algorithms affected the ability to assess anatomical visibility. Image quality appeared either high or assessable for diagnostic purposes in 9 out of 14 of the ipsilateral structures, in at least one plane. Anatomical structures contralateral to the cochlear implant were highly visible in all conditions. Artifact intrusion clearly improved after application of metal artifact-reduction techniques. In the case of bilateral cochlear implant, a mutual interaction between the two implant magnets produced an additional artifact. CONCLUSIONS: We performed the first cadaver study aimed at systematically evaluating the MRI-induced artifacts produced by a cochlear implant with a novel four bar magnet system. Specific brain structures can be assessable for diagnostic purposes under 1.5 T MRI, with the cochlear implant magnet in place.

Feasibility of 3D printed salivary duct models for sialendoscopic skills training: preliminary report.

PURPOSES: To explore the feasibility of 3D printed salivary duct models for the sialendoscopic skills training. METHODS: Healthy volunteers and patients affected by obstructive salivary gland disorders were submitted to 3 Tesla MR sialography. The MR data underwent an image segmentation process to produce the 3D printed salivary duct prototypes. Sialendoscopies were carried out by three groups of investigators with different levels of endoscopic experience. Realism, usefulness of the training process and potential advantages of the 3D printed models in the preoperative surgical planning were evaluated by means of a specific survey. RESULTS: Four cases were included in our study: one healthy parotid, one submandibular gland, one case of lithiasis and one of stenosis involving the parotid gland. In all cases, the three groups of investigators successfully explored the salivary ducts up to the tertiary branches, detected the cause of obstruction and correctly treated it. Seven untoward events occurred during the operative sialendoscopies. Overall, the questionnaire score was about 79.3%, reflecting a positive impression regarding the models on behalf of all the investigators. CONCLUSIONS: 3D printed salivary duct models resulted feasible for the sialendoscopic skills training. The opportunity to reproduce the patient-specific anatomy may add further information useful in the preoperative decision making. These positive results should be verified by further researches and experiences.

Gradenigo's syndrome with abscess of the petrous apex in pediatric patients: what is the best treatment?

BACKGROUND: Gradenigo's syndrome is defined by the classic clinical triad of ear discharge, trigeminal pain, and abducens nerve palsy. It has become a very rare nosological entity after the introduction of antibiotics, so that has been defined as the "forgotten syndrome." However, the underlying pathological process (apical petrositis) still represents a life-threatening condition that shall be immediately recognized in order to address the patient to the proper therapy. The therapy itself may be an argument of discussion: on a historical background ruled by surgery, reports of successful conservative antibiotic treatment have risen in recent years. METHODS AND RESULTS: We reported a case of Gradenigo's syndrome in a child with an abscess of the left petrous apex and initial involvement of the carotid artery. After multidisciplinary evaluation, we decided to encourage conservative treatment, until complete regression was observed. DISCUSSION: The available literature of the last 10 years was reviewed, with particular attention to the presence of an apical abscess and the therapeutic approach. The principles of management with regard to conservative therapy versus surgical indications are therefore examined and discussed.

"Emergency" Cochlear Implantation in Labyrinthitis Ossificans Secondary to Polyarteritis Nodosa: How to Face a Rare Entity.

Polyarteritis nodosa (PAN) is a systemic vasculitis affecting the small- and medium-sized arteries that may present with hearing impairment. In rare cases, PAN may be associated with progressive labyrinthitis ossificans (LO), an otologic emergency requiring early cochlear implantation (CI) to restore hearing before the complete, irreversible cochlear ossification. We report the first case in the literature of a patient affected by PAN with bilateral sudden sensorineural hearing loss and rapid LO who underwent "emergency" bilateral simultaneous CI. This case report emphasizes the importance of an early audiological evaluation in patients with PAN when LO is suspected. Multidisciplinary approach is mandatory when facing organ-specific manifestations in patients with PAN. Detailed discussion is provided with particular regard to clinical and radiological presentation as well as CI outcomes in such a rare and challenging case.

Translabyrinthine vestibular neurectomy and simultaneous cochlear implant for Ménière's disease.

BACKGROUND: Surgical management of Ménière's disease (MD) is recommended in case of medical and intratympanic treatment failures. Translabyrinthine vestibular nerve section has been considered the gold standard for denervation procedures in order to control vertigo attacks, although at the cost of sacrificing residual hearing. To the best of our knowledge, no work has been published with regard to a group of patients submitted to translabyrinthine vestibular neurectomy and simultaneous cochlear implant for MD. The aim of the present study was to assess the effectiveness of translabyrinthine vestibular nerve section and simultaneous cochlear implant in a prospective study. METHODS: All adult patients (over 18 years of age) with a diagnosis of intractable unilateral definite MD and useless residual hearing function were enrolled after medical and intratympanic treatment failures. Pre- and postoperative otoneurological evaluation concerned: frequency of vertigo attacks, head impulse test and caloric testing, pure tone average and speech perception audiometry in quiet conditions, tinnitus handicap inventory test, functional level scale and rate of vertigo control, dizziness handicap inventory test, and MD patient-oriented severity index. At least 6 months of follow-up were needed to be enrolled in the study. RESULTS: Four patients were included in the study. Translabyrinthine vestibular nerve section and simultaneous cochlear implant seemed to considerably improve the disabling effects of MD, achieving a good control of vestibular symptoms (mean pre/postoperative vertigo attacks per month: 16.5/0), resolving hearing loss (mean pre/postoperative pure tone average in the affected ear: 86.2/32.5 dB), improving the tinnitus (mean pre/postoperative tinnitus handicap inventory test: 77.2/6), and finally increasing the overall quality-of-life parameters. CONCLUSIONS: In our preliminary report, translabyrinthine vestibular nerve section and simultaneous cochlear implant showed encouraging results in order to definitively control both vestibular and cochlear symptoms during the same therapeutic procedure.