Tracheal Portion Research Articles

Primary Tracheal Squamous Cells Carcinoma in a Dog

Primary tracheal neoplasms are uncommon and poorly documented in veterinary medicine, being most frequently reported in domestic cats. Squamous cell carcinoma (SCC) is a malignant neoplasm that originates from the stratified squamous epithelium, considered one of the most common skin neoplasms in dogs and cats. This paper aims to report the anatomopathological and immunohistochemical findings of a clinical case of primary SCC in the trachea of a female Schnauzer canine, attended at the Veterinary Hospital Luiz Quintiliano de Oliveira of the Faculty of Veterinary Medicine of Araçatuba (FMVA – UNESP), complaining of choking, coughing and dyspnea for 1 month. The tracheal portion affected by the neoplasm was sent to the Veterinary Pathology department of the FMVA after surgical excision. Fragments of the neoplasm were collected and fixed in 10% formaldehyde for further histopathological and immunohistochemical analysis. Microscopically, the neoplasm was well differentiated, being characterized by the presence of keratin pearls, low degree of pleomorphism and rare mitotic figures. In the immunohistochemical analysis, there was immunoexpression of anti-cytokeratin antibodies AE1AE3, 34BE12, CK14 and CK5/6, confirming the diagnosis of squamous cell carcinoma. In about 30% of the cells there was immunostaining for Ki67 antibodies, justifying the low mitotic index of tumor cells and the few images of mitosis seen. Due to the rare occurrence of primary tracheal SCC in dogs, the use of diversified diagnostic techniques is important in order to better understand the biological behavior of this neoplasm in unusual anatomical locations.

Ventilation Impairment During Anesthesia in Patients with Anterior Mediastinal Mass

Because of location, a mediastinal mass may cause complications such as a major airway obstruction, a superior vena caval obstruction, and cardiac compression during general anesthesia. The patient's condition need to be assessed by several methods to predict the risks associated with general anesthesia. The authors took computed tomographs for a preoperative evaluation of two patients with an anterior mediastinal mass, and the risk of perioperative complications was predicted by measuring the tracheal area. The patients were managed according to the preoperative evaluation but severe ventilation impairments were encountered during anesthesia. In one patient, stable ventilation could not be maintained until spontaneous breathing appeared. The operation was cancelled and the patient was brought into the ICU. In the other patient, a tracheal tube was inserted deeper in an attempt to pass the narrowed tracheal portion due to mediastinal tumor compression resulting in improved ventilation.

Inertial Deposition Effects: A Study of Aerosol Mechanics in the Trachea Using Laser Doppler Velocimetry and Fluorescent Dye

This study characterizes the axial velocity and axial turbulence intensity patterns noted in the tracheal portion of a cadaver-based throat model at two different steady flow rates (18.1 and 41.1 LPM.) This characterization was performed using Phase Doppler Interferometry (Laser Doppler Velocimetry). Deposition, as assessed qualitatively using fluorescent dye, is related to the position of the laryngeal jet within the trachea. The position of the jet is dependent on the downstream conditions of the model. It is proposed therefore that lung/airway conditions may have important effects on aerosol deposition within the throat. There is no correspondence noted between regions of high axial turbulence intensity and deposition.

Characterization of the laryngeal jet using phase Doppler interferometry.

The purpose of this study was to characterize the effects of the laryngeal jet on inhalation air flows in the trachea, and to extend these ideas to further an understanding of aerosol deposition in this region. Phase Doppler Interferometry was used to characterize axial velocity and turbulence intensity contours in the tracheal section of a cadaver-based larynx-trachea model. An array of 30 measurements was made at each of 6 downstream planes within the tracheal portion of the model (immediately downstream of the larynx, and at 0.5, 1, 2, 3, and 4 diameters further downstream). The flow was characterized for steady state flow at three Reynolds numbers (1250, 1700, and 2800). The Re = 1250 case approximates the inhalation of a 6-year-old child. Reverse flows with significant velocities were noted in the anterior trachea within one diameter downstream of the larynx, for all three flow cases. The cross sectional area of the reverse flow regions was larger for the lower Reynolds number cases. These reverse flows are a consequence of the nearly triangular shape of the lumen between the vocal folds in the larynx and constitute a potential deposition mechanism. High levels of axial turbulence intensity were noted near the anterior/left tracheal walls within one diameter downstream of the larynx. This indicates the potential for deposition due to turbulence in this region. Turbulence levels were still significant after four downstream diameters, indicating the potential for turbulent deposition at positions further downstream, including the bronchial tree where passage diameters are smaller. Contrary to expectations, turbulence levels were approximately 20% higher for the Re = 1250 case compared to the Re = 2800 at the furthest downstream locations (with 99% confidence). This is likely due to the complex nature of the confined jet flow.

喉頭麻ひの病態生理 特に声帯位について

Twenty four cases of unilateral laryngeal paralysis were examined by contrast laryngography. The characteristic feature of the laryngeal paralysis in these contrast laryngogram was that the vocal fold on the affected side was fixed in the half adducted position during respiration. This corresponded to the laryngoscopic view of the vocal fold fixed at the intermediate position. During phonation, the larynx was seen to be elevated, and the shape of the laryngeal cavity changed. However, the tracheal portion of the vocal tract did not change on the contrast laryngogram. When the contrast laryngograms taken during respiration and phonation were superimposed at the unchanging tracheal portion, the movement of the vocal folds could be measured and quantified. The vocal fold on the affected side was slightly adducted during phonation in 10 out of the 24 cases of unilateral paralysis, and abducted in 2 cases (paradoxical movement due to misdirected regeneration of the recurrent laryngeal nerve) and fixed in the rest 12 cases. The position of the vocal fold on the affected side during phonation was related to its mobility. When it was slightly adducted, it seemed to be fixed at the paramedian position in the laryngoscopic examination. When it was not adducted, it was fixed at the intermediate position.

Demonstration of the release of an epithelium-derived inhibitory factor from a novel preparation of guinea-pig trachea

Using a novel preparation of guinea-pig trachea, direct evidence was obtained for the release of an epithelium-derived inhibitory factor modulating contractions elicited by antigen. Thus, epithelium removal produced a 6.1-fold leftward shift in ovalbumin concentration-response curves in tracheal strips from ovalbumin-sensitized guinea-pigs. This increase in sensitivity to ovalbumin was not evident when a tracheal portion containing epithelium was positioned in close proximity to the tissue from which tension was recorded.

An X-ray Study on the Level of the Vocal Fold During Phonation

In the laryngograms taken during phonation and respiration, the figure of the tracheal portion itself remains unchanged. When both laryngeal figures are superimposed at the tracheal portion, movement of the vocal fold in the laryngeal cavity can be quantitatively mesured. This method was applied to the observation of the level of the glottis during phonation. The larynx is elevated during phonation, but the vocal fold moves downward in the laryngeal cavity. Therefore, the vertical movement of the vocal fold is radiographically considered in two ways; movement relative to the surrouding tissue and absolute movement in the laryngeal cavity. The latter movement was discussed in this study.1) The level of the glottis during phonation is 3mm to 4mm lower than during respiration.2) In male subjects, the higher the pitch ascends, the lower the glottis descends in the same register. In female cases, the same phenomenon is found only in the range of low voice.3) At the same pitch, the level of the glottis during phonation of chest voice is lower than that of head voice.

Functional Test of the Larynx by the Superimposing Method of Laryngograms

Both laryngograms during phonation and inspiration illustrate the same figure at the portion of the trachea. When both laryngeal figures are superimposed at the tracheal portion, movement of the vocal fold is to be quantitatively measured in two dimensions, horizontally and vertically. This method was applicated to cases of the recurrent laryngeal nerve paralysis and the laryngeal carcinoma. In the former, it was clarified that the paralysed vocal fold slightly adducts during phonation especially in all cases it shows no atrophy. In the latter, the invasion of carcinoma into the vocal muscle was more exactly diagnosed by the extent of adduction of the diseased vocal fold.