Accessing the stapedius muscle via novel surgical retrofacial approach during cochlear implantation surgery: Intraoperative results on feasibility and safety.

Human stapedius muscle (SM) can be directly and safely accessed via retrofacial approach, opening new approaches to directly measure the electrically evoked stapedius reflex threshold (eSRT). The measurement of the SM activity via direct surgical access represents a potential tool for objective eSRT fitting of cochlear implants (CI), increasing the benefit experienced by the CI users and leading to new perspectives in the development of smart implantable neurostimulators. 3D middle-ear reconstructions created after manual segmentation and related SM accessibility metrics were evaluated before the CI surgery for 16 candidates with assessed stapedius reflex. Retrofacial approach to access the SM was performed after facial recess exposure. In cases of poor exposition of SM, the access was performed anteriorly to the FN via drilling of the pyramidal eminence (PE). The total access rate of the SM via both the retrofacial and anterior approach of the FN was 100%. In 81.2% of cases (13/16), the retrofacial approach allowed to access the SM on previously categorized well exposed (8/8), partially exposed (4/5), and wholly concealed (1/3) SM with respect to FN. Following intraoperative evaluation in the remaining 18.8% (3/16), the SM was accessed anteriorly via drilling of the PE. Exposure of SM with respect to the FN and the sigmoid sinus's prominence was a predictor for the suitable surgical approach. The retrofacial approach offers feasible and reproducible access to the SM belly, opening direct access to electromyographic sensing of the eSRT. Surgical planner tools can quantitatively assist pre-surgical assessment.

Neuroprotective Effects of the Inert Gas Argon on Experimental Traumatic Brain Injury In Vivo with the Controlled Cortical Impact Model in Mice.

Argon has shown neuroprotective effects after traumatic brain injury (TBI) and cerebral ischemia in vitro and in focal cerebral ischemia in vivo. The purpose of this study is to show whether argon beneficially impacts brain contusion volume (BCV) as the primary outcome parameter, as well as secondary outcome parameters, such as brain edema, intracranial pressure (ICP), neurological outcome, and cerebral blood flow (CBF) in an in-vivo model. Subjects were randomly assigned to either argon treatment or room air. After applying controlled cortical impact (CCI) onto the dura with 8 m/s (displacement 1 mm, impact duration 150 ms), treatment was administered by a recovery chamber with 25%, 50%, or 75% argon and the rest being oxygen for 4 h after trauma. Two control groups received room air for 15 min and 24 h, respectively. Neurological testing and ICP measurements were performed 24 h after trauma, and brains were removed to measure secondary brain damage. The primary outcome parameter, BCV, and the secondary outcome parameter, brain edema, were not significantly reduced by argon treatment at any concentration. There was a highly significant decrease in ICP at 50% argon (p = 0.001), and significant neurological improvement (beamwalk missteps) at 25% and 50% argon (p = 0.01; p = 0.049 respectively) compared to control.

Accessing the Stapedius Muscle Via Novel Surgical Retrofacial Approach: A Cadaveric Feasibility Study.

HYPOTHESIS: Despite the complete embodiment of the stapedius muscle (SM) into the pyramidal eminence, it is possible to safely gain access to the SM belly via a retrofacial approach. This presents a novel approach to directly measure the electrically evoked stapedius reflex threshold (eSRT). BACKGROUND: Objective fitting of maximum comfortable loudness levels for cochlear implant users can improve the benefit introduced by the device. Sensing SM activity via direct surgical access represents a potential tool for objective eSRT fitting. METHODS: Eighteen human temporal bones (TBs) were used. Micro-computed tomography was performed for six TBs. Standard computed tomography for six TBs. Manual 3D-segmentation of the relevant middle and inner ear anatomy was performed on 12 TBs. Mastoidectomy and posterior tympanotomy allowed the access to middle ear of all 18 the TBs. Once identified the mastoidal segment of the facial nerve (FN), the retrofacial access to the SM was drilled. RESULTS: The total access rate was 72.2%. Only in the first three cases the posterior semi-circular canal was hit. The SM access was identified posterior to the FN at a 4 ±â€Š0.78 mm distance from the stapes' head, almost halfway to the chorda tympani's branching point along the FN direction. The drilling depth to access the SM posterior to the external surface of FN on average was 2 ±â€Š0.30 mm. The exposure took on average of 5 to 8 minutes. CONCLUSIONS: The retrofacial approach seems to offer a feasible and reproducible access to the SM belly opening an avenue to electromyographic sensing of eSRT.

Immediate effects of COVID-19 on the global dairy sector.

CONTEXT: The emergence and rapid spread of the coronavirus disease (COVID-19) has posed an unprecedented threat to both societies and economies. The dairy sector is an example of the challenges that food supply chains have faced due to the pandemic. OBJECTIVE: This study aims to provide primary evidence of the immediate effects of COVID-19 on the global dairy sector, particularly focusing on the outcome of the implemented response mechanisms, and the potential medium and long-term implications of the pandemic on the sector. METHODS: We employed a longitudinal qualitative analysis framework that combines the use of questionnaires, media-search, focus-group discussions, semi-structured interviews, and secondary evidence reviews. Information was gathered at two points in time: three months after the beginning of the outbreak and one year later. We applied this framework in five different geographical regions: Africa, Asia, Europe, Latin America, and North America. RESULTS AND CONCLUSIONS: Our study indicates that the pandemic has been perceived as a series of episodes affecting the sector from both demand and supply sides. These waves have impacted the sector differently depending on regions and countries' trade profiles, relative resource scarcity, per capita income, and market structure. Although in one year the sector has mostly recovered from the shock, the analysis concludes that the pandemic has accelerated on-going structural changes taking place in the dairy sector. SIGNIFICANCE: The study expands existing knowledge about the effects of the pandemic on the dairy sector and adds to the newly evolving literature about the medium and long-term effects of the COVID-19 on food systems across the globe. Despite the preliminary nature of the results, they provide important insights to inform sectorial policy discussions.