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Conditions of the External Ear
Published in R James A England, Eamon Shamil, Rajeev Mathew, Manohar Bance, Pavol Surda, Jemy Jose, Omar Hilmi, Adam J Donne, Scott-Brown's Essential Otorhinolaryngology, 2022
Ayeshah Abdul-Hamid, Samuel MacKeith
Solid atresia consists of a continuous block of fibrosis from the TM. Membranous atresia is typified by a fibrous tissue that has a covering of canal skin on both sides, separating the ear canal into two segments. The medial segment inevitably collects keratin, which may become erosive. Stenosis may also cause this. Atresia may be caused by the following processes: InflammationChronic OEChronic otitis mediaTraumaBurnsSurgery especially involving a meatal approach
How to dissect the plane between the scar of a laminectomy defect in the posterior thoracic and lumbar spine
Published in Gregory D. Schroeder, Ali A. Baaj, Alexander R. Vaccaro, Revision Spine Surgery, 2019
Nickul S. Jain, Raymond J. Hah
Magnetic resonance imaging (MRI), with and without IV contrast, is critical to determine areas of compression of neural elements. The addition of gadolinium can help distinguish peridural fibrosis from recurrent disc herniation or residual stenosis. Additionally, MRI will show an asymptomatic contained pseudomeningocele, which may need to be avoided or addressed. MRI imaging must also be carefully examined to determine the site of stenosis: central, lateral recess, or foraminal. Examination of the residual bony anatomy (both normal and previously altered) to establish how much additional bony resection may be required. This distinction will allow an appropriate surgical plan to maximize chances of success. MRI will show the transition zone between native and previously operated anatomy in order to find a safe entry point for dissection (Figure 3.1). In patients with previous instrumentation, visualization of neural elements is obscured due to artifacts. In these situations, computed tomography (CT) myelogram can be useful.
Otorhinolaryngology
Published in Stephan Strobel, Lewis Spitz, Stephen D. Marks, Great Ormond Street Handbook of Paediatrics, 2019
Chris Jephson, C. Martin Bailey
Treatment depends upon the grade of stenosis and may include endoscopic or open surgery. For the failed neonatal extubation, a cricoid split procedure may be suitable. Grade I stenosis may need no treatment if symptoms are mild. More severe grades may require laryngotracheal reconstruction using a costal cartilage graft (with or without a covering tracheostomy).
Modelling and simulation of fluid flow through stenosis and aneurysm blood vessel: a computational hemodynamic analysis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
J. V. Ramana Reddy, Hojin Ha, S. Sundar
In the present study, the stenosis is assumed to be mild. Therefore, the parameters associated with the mild stenosis i.e., l, the model behaves as a Newtonian model. The γ, and the subscript T and C is corresponding to the coefficient of thermal expansion due to temperature and concentration, respectively. The expression to compute the Brownian motion parameter and thermophoresis parameter are
Balloon-mounted versus self-expanding stents for symptomatic intracranial vertebrobasilar artery stenosis combined with poor collaterals
Published in Neurological Research, 2019
Yong Zhang, Gary B. Rajah, Peng Liu, Yujie Sun, Tonghui Liu, Xin Li, Zhongrong Miao, Guangwen Li
This study was a retrospective single-arm registry analysis of a prospectively maintained stroke database from 20 participating stroke centers in China. This study included all consecutive patients with intracranial vertebrobasilar artery atherosclerotic stenosis who were treated by balloon-mounted stents or balloon plus self-expanding stents from September 2013 until January 2015. All the participating stroke centers were required to obtain local institution review board or ethics committee approval in accordance with the Health Insurance Portability and Accountability Privacy Act. Written and verbal informed consent was obtained from patients according to the Helsinki Declaration. The diagnosis of stenosis was confirmed by at least one imaging modality, including computer tomography angiography (CTA) or magnetic resonance angiography (MRA) and further validated by digital subtraction angiography (DSA). The therapy was decided by a central adjudication committee composed of designated neurologists, neurosurgeons and radiologists. The conduction, safety and efficacy of the study were monitored by an independent Data and Safety Monitoring Board.
Barotrauma after liquid nitrogen ingestion: a case report and literature review
Published in Postgraduate Medicine, 2018
Yuemei Zheng, Xiaoxia Yang, Xinli Ni
In these clinical cases, the patients rarely had cold-induced injuries to the mouth, oropharynx, upper airway, or esophagus. Medical specialists should be aware of these special injury features of swallowing a beverage containing liquid nitrogen. The lack of injuries to these sites is attributed to the Leidenfrost effect [2,3], in which a liquid encountering a temperature significantly higher than its boiling point generates an insulating vapor layer that slows thermal transfer. This mechanism is seen when water thrown into a very hot frying pan creates dancing droplets that skitter about instead of boiling. The liquid nitrogen in the present case evaporated rapidly, creating a layer of high-pressure gaseous insulation entrapping the cold inside, thus protecting the surrounding tissue from cold injury. This explains why the patient had only a small area of mucosal injury. Nevertheless, inhalation of liquid nitrogen gas can lead to mucosal injury in the upper airway, oropharynx, or hypopharynx with a risk of delayed perforation at these sites. Stenosis and infection of the injured sites are two potential complications. Furthermore, the gas absorbed from the tissue may replace oxygen in the bloodstream and cause asphyxia-induced neurologic symptoms and death [4,5].