Tracheal Schwannoma Presenting as Subcutaneous Emphysema and Pneumomediastinum.

Primary tracheal schwannomas are rare benign tumours. This is a case report, and therefore, no specific methods or results are applicable. We here report a case of a tracheal schwannoma in an early adolescent girl presenting with subcutaneous emphysema and symptoms of airway obstruction. Tracheal resection and reconstruction by primary anastomosis were performed. Pathology confirmed the diagnosis of tracheal schwannoma. This is an unusual life-threatening presentation of a benign rare tracheal tumour with a challenging approach to management.

Double lumen endobronchial tube intubation: lessons learned from anatomy.

BACKGROUND: Double lumen endobronchial tubes (DLTs) are frequently used to employ single lung ventilation strategies during thoracic surgical procedures. Placement of these tubes can be challenging even for experienced clinicians. We hypothesized that airway anatomy, particularly of the glottis and proximal trachea, significantly impacts the ease or difficulty in placement of these tubes. METHODS: Images from 24 randomly selected Positron Emission Tomography - Computed Tomography (PET-CT) scans were evaluated for several anatomic aspects of the upper airway, including size and angulation of the glottis and proximal tracheal using calibrated CT measurements and an online digital protractor. The anatomic issues identified were confirmed in cadaveric anatomic models. RESULTS: Proximal tracheal diameter measurements in PET-CT scans demonstrated a mean ± standard deviation of 20.4 ± 2.5 mm in 12 males and 15.5 ± 0.98 mm in 12 females (p < 0.001), and both were large enough to accommodate 39 French and 37 French DLTs in males and females, respectively. Subsequent measurements of the posterior angulation of the proximal trachea revealed a mean angle of 40.8 ± 5.7 degrees with no sex differences. By combining the 24 individual posterior tracheal angles with the 16 angled distal tip measurements DLTs (mean angle 24.9 ± 2.1 degrees), we created a series of 384 patient intubation angle scenarios. This data clearly showed that DLT rotation to a full 180 degrees decreased the mean intubation angle between the DLT and the proximal trachea from a mean of 66.6 ± 5.9 to only 15.8 ± 5.9 degrees. CONCLUSIONS: Rotation of DLTs a full 180 instead of the recommended 90 degrees facilitates DLT intubations.

Benign cervical schwannoma with tracheal invasion.

Schwannomas commonly develop in the cervical region, 25% - 45% of cases are diagnosed in this anatomical region. Tracheal neurogenic tumors are exceedingly rare and can be misdiagnosed as invasive thyroid carcinomas or other infiltrating malignancies when present at the level of the thyroid gland. Here, we present a case of synchronous benign cervical schwannoma with tracheal invasion and papillary thyroid carcinoma in a patient who was initially hospitalized for COVID-19. The patient presented with dyspnea that was later found to be caused by tracheal extension of a cervical tumor. Surgical excision was performed, and the surgical team proceeded with segmental tracheal resection, removal of the cervical mass, and total thyroidectomy. The specimen was sent for pathological analysis, which revealed synchronous findings of a benign cervical schwannoma with tracheal invasion and papillary thyroid carcinoma. The literature on this subject, together with the present case report, suggests that neurogenic tumors should be included in the differential diagnosis of obstructing tracheal cervical masses. Surgical excision is the first-line of treatment for benign cervical schwannomas.

Determining optimal cuff volume for cuffed endotracheal tubes commonly used in pediatric patients: A prospective observational study.

OBJECTIVES: To determine an optimal cuff inflation volume to achieve safe cuff pressure (20-25 cmH2O) in cuffed endotracheal tubes (ETTs) with an inner diameter of 4.5, 5.0, and 5.5 mm, which are commonly used in pediatric anaesthesia clinical practice and to create a formula to determine the optimal cuff volume. METHODS: This study was carried out between February and June 2021 in Ankara City Hospital, Ankara, Turkey. A total of 127 pediatric patients who were intubated with 4.5, 5.0 and 5.5 numbered cuffed ETTs were included in this study. The same brand of cuffed ETT was used for each patient. The diameter of the subglottic transverse airway was measured by ultrasound for selecting the appropriate tube. Cuff pressure was measured with a cuff manometer to ensure optimum cuff pressure (20-25 cmH2O). RESULTS: We found out that the mean ideal cuff volume inflated for 4.5 size tube was 1.7±0.3 ml, 1.9±0.3 ml for 5.0 size tube, and 2.1±0.3 ml for 5.5 size tube. Additionally we developed the "endotracheal cuff volume (ml) = 1,027 x height (m) + 0,104 x subglottic transverse diameter (mm) - 0,0191" formula to predict the most suitable inflation volume for ETT cuffs. CONCLUSION: In this study, we suggested the optimal cuff volume to inflate the cuffs of ETTs 4.5, 5.0, and 5.5, which are frequently used in pediatric anaesthesia practice, in the appropriate cuff pressure range.ClinicalTrials.gov ref. no.: NCT04948359.

Laryngotracheoesophageal Cleft Type IV in a Preterm Neonate. A Case Report and Literature Review.

We present a case of a preterm neonate with a type IV laryngo-tracheo-oesophageal cleft, an uncommon congenital malformation, resulting from the failure of separation of the trachea and the oesophagus during fetal development, often associated with other deformities as well. Data in the literature shows that the long-term morbidity from the entity has declined over the last decades, even though prognosis remains unfavourable for types III and IV. This report emphasizes the complex issues neonatologists are faced with, when treating neonates with this rare disorder in the first days of life, what will raise suspicion of this rare medical entity, and that direct laryngoscopy/bronchoscopy finally depicts the exact extension of the medical condition. At the same time extensive evaluation for coexisting congenital anomalies should be performed. For all the above reasons, these neonates should be treated in specialized tertiary pediatric centers for multidisciplinary prompt management, which may improve, the outcome.

Dynamic airway computed tomography and flexible bronchoscopy for diagnosis of tracheomalacia in children: A comparison study.

INTRODUCTION: Tracheomalacia (TM) is an important cause of respiratory morbidity. Dynamic flexible bronchoscopy is considered the gold standard for diagnosis. Dynamic airway computed tomography (DACT) is a low radiation, noninvasive diagnostic tool utilizing images obtained continuously over several respiratory cycles. We aimed to assess the accuracy of DACT in TM diagnosis. METHODS: Retrospective analysis of all patients who underwent both DACT and flexible bronchoscopy within 6 months. Airway anterior-posterior (AP) diameter was measured on multiplanar reconstructions CT in both the inspiratory and expiratory phases. Using still images from the bronchoscopy videos, the AP diameter of the trachea was measured at points of maximal and minimal diameter during tidal breathing. Degree of TM on both DACT and flexible bronchoscopy were graded using a scaling system of 50%-74%, 75%-89%, and 90%-100% as described by the European Respiratory Society. RESULTS: Twenty-four patients met inclusion criteria with an average time of 19.5 days between CT and bronchoscopy. The specificity and sensitivity of DACT for the overall diagnosis of TM was 100% and 68%, respectively, with a positive predictive value of 100% and a negative predictive value of 62%. There was a strong positive correlation between DACT and flexible bronchoscopy in the measurement of tracheal AP diameter changes (ρ = 0.773, R2 0.597, p = 0.00001). Mean effective radiation dose for DACT was 0.1 mSv. CONCLUSION: Ultralow dose DACT has excellent specificity and positive predictive value for both detection of TM and categorizing severity of tracheal collapse but is not sufficiently sensitive to rule it out.

Preoperative point-of-care neck ultrasound: beyond the airway.

PURPOSE: A preoperative point-of-care neck ultrasound, carried out during preoperative airway evaluation by extending the scans to the regions close to the larynx and trachea, can allow for the rapid identification of unknown pathologies or abnormalities in a cost-effective and non-invasive manner. This prospective, observational study examines a series of ultrasound findings in structures close to the airway, made through preoperative point-of-care neck ultrasound in a cohort of 230 patients. METHODS: We conducted a prospective observational study, enrolling 230 adult patients selected for elective abdominal surgery. The primary goal was to verify the predictive role of airway ultrasound in identifying difficult airways, while the secondary goal was to evaluate structures close to the airway such as jugular veins, carotid arteries, thyroid gland and soft tissues. RESULTS: Overall, preoperative point-of-care neck ultrasound proved to be an effective and reliable method of obtaining details about local or systemic pathologies, which could affect perioperative care. For example, the exam consistently revealed the presence of carotid plaques or venous congestion, which could be used to best determine the patient's cardiovascular risk or to instigate further investigations. It also allowed for more accurate central venous catheter placement planning and better airway management and it warned about possible thyroid or neoplastic pathologies that would have otherwise remained unknown. In some cases, information from preoperative point-of-care neck ultrasound has even led to modifications in perioperative therapy. CONCLUSION: Preoperative point-of-care neck ultrasound is fast, inexpensive, and non-invasive, and it can be easily performed by a properly trained professional during the preoperative airway ultrasound evaluation. It can be considered as a new preoperative assessment tool.

Co-axial Endotracheal Tube Technique for Achieving One Lung Ventilation in a Toddler With a Space Occupying Malignant Tumor of the Right Lung.

Achieving one-lung ventilation in pediatrics is often challenging. In caring for these patients, the anesthesiologist must consider the child's age and size, underlying tracheobronchial anatomy, equipment availability, urgency of procedure, and as well as the experience level of the anesthesiologist. This report describes a "tube-inside-tube" technique that was adopted for providing one-lung ventilation in a toddler. The method described here involved railroading a smaller endotracheal tube over a flexible intubation video endoscope into the left mainstem bronchus coaxially through a larger endotracheal tube placed in the trachea. The technique achieved effective left-lung ventilation and isolation of the operative right lung during surgical resection of a malignant mesenchymal tumor. On completion of the procedure, double-lung ventilation could be established through the endotracheal tube in the trachea after the retraction of the video endobronchial tube.

Bronchial tree of the human embryo: Examination based on a mammalian model.

The symmetry of the right and left bronchi, proposed in a previous comparative anatomical study as the basic model of the mammalian bronchial tree, was examined to determine if it applied to the embryonic human bronchial tree. Imaging data of 41 human embryo specimens at Carnegie stages (CS) 16-23 (equivalent to 6-8 weeks after fertilization) belonging to the Kyoto collection were obtained using phase-contrast X-ray computed tomography. Three-dimensional bronchial trees were then reconstructed from these images. Bronchi branching from both main bronchi were labeled as dorsal, ventral, medial, or lateral systems based on the branching position with numbering starting cranially. The length from the tracheal bifurcation to the branching point of the labeled bronchus was measured, and the right-to-left ratio of the same labeled bronchus in both lungs was calculated. In both lungs, the human embryonic bronchial tree showed symmetry with an alternating pattern of dorsal and lateral systems up to segmental bronchus B9 as the basic shape, with a more peripheral variation. This pattern is similar to that described in adult human lungs. Bronchial length increased with the CS in all labeled bronchi, whereas the right-to-left ratio was constant at approximately 1.0. The data demonstrated that the prototype of the human adult bronchial branching structure is formed and maintained in the embryonic stage. The morphology and branching position of all lobar bronchi and B6, B8, B9, and the subsegmental bronchus of B10 may be genetically determined. On the other hand, no common structures between individual embryos were found in the peripheral branches after the subsegmental bronchus of B10, suggesting that branch formation in this region is influenced more by environmental factors than by genetic factors.

Lower airway ultrasonographic, endoscopic, and cytological changes in horses undergoing inhalation anesthesia with controlled ventilation for minor elective surgeries.

Effects of general anesthesia with controlled ventilation on the respiratory system have had limited evaluation in horses. A prospective observational study was performed with eleven client-owned horses undergoing elective surgery. Physical examination, auscultation with a rebreathing bag, complete blood cell count, lung ultrasound imaging, tracheal endoscopy imaging and transendoscopic tracheal wash were conducted before and 24 hours after anesthesia. Lung ultrasound imaging was also repeated just after recovery. A significant increase in blood neutrophil count between pre- and post-anesthesia (P=0.004) was observed. There was an increase in ultrasonographic score of the lungs at recovery (left P=0.007, right P=0.017). The score of the dependent lung was higher than the independent lung at recovery time (P=0.026) but no difference was observed 24 hours after anesthesia. The tracheal mucus score was higher after anesthesia (P=0.001); severe local inflammation was present in several horses at the site of endotracheal tube cuff. Neutrophil count was significantly higher on tracheal wash fluid cytology after anesthesia (P=0.016), without any significant changes on bacterial load. Increased tracheal mucus score and neutrophil count in tracheal wash samples were observed after general anesthesia in healthy horses without clinical evidence of pneumonia (fever, cough). Tracheal inflammation secondary to endotracheal intubation and cuff inflation was, therefore, suspected. Elective surgery without complications can induce inflammation of the trachea and changes in ultrasound images of the lungs in healthy horses and should be considered when evaluating respiratory system after a general anesthesia.

Radiographic and computed tomographic evaluation of tracheal diameter and length in kittens.

OBJECTIVE: To measure the tracheal diameter and length in kittens using radiography and CT and to evaluate the concordance between measurements obtained with these 2 modalities. ANIMALS: 15 kittens with an estimated age of 12 weeks and mean body weight of 1.49 kg. METHODS: Radiographic and CT images were retrospectively evaluated to measure tracheal lengths and diameters. Tracheal diameters were measured at 5 different sites (A [at the level of the C2-3 intervertebral disk space], B [at the level of the C4-5 intervertebral disk space], C [at the cranial end of the manubrium sterni], D [at the level of the second rib], and E [1 cm cranial to the carina]) along the trachea. The cross-sectional area and transverse and vertical diameter ratios were calculated for each measurement site. RESULTS: The cross-sectional area was largest at site A and decreased from site C to site E. Based on the vertical diameter ratio, the tracheal shape was most circular at sites A and E, whereas from sites B to D, it was elliptical. The vertical diameters of the trachea on radiography and CT did not differ statistically significantly. However, the tracheal length measured on radiography was approximately 6 mm longer than that measured on CT (P < .05). CLINICAL RELEVANCE: Using the first rib as an anatomical reference, the placement of a cuffed endotracheal tube is recommended in kittens. In emergency situations, regression equations based on body weight may be helpful in predicting tracheal diameters.

The accuracy of the ultrasound measured transverse cricoid diameter and the epiphyseal transverse diameter of the distal radius in predicting the pediatric endotracheal tube size.

BACKGROUND: In everyday pediatric anesthesia practice, clinicians frequently exchange an already inserted endotracheal tube because of a leak or resistance causing significant morbidity. We investigated the accuracy of two ultrasound measurements; the transverse cricoid diameter and epiphyseal diameter of the distal radius in the prediction of endotracheal tube size that best fits in children compared to age-based formulas. PATIENTS: One hundred children (1-6 years) who underwent elective surgery with endotracheal tube whether cuffed (n = 50) or uncuffed (n = 50) were enrolled. The primary endpoint was the agreement between the reference tube size for which its outer diameter was selected based on transverse cricoid diameter and the final best-fit-ETT. The Correlation and Bland Altman agreement tests were conducted between best-fit-ETT outer diameter and ultrasound-measured outer diameter, and between best-fit-ETT inner diameter and inner diameter calculated by age-based formulas. RESULTS: The agreement rate between transverse cricoid diameter-based endotracheal tube size and best-fit-ETT size was 88% in cuffed group compared to 90% in uncuffed group. A significant positive correlation was reported between the outer diameter of best-fit-ETT and the outer diameter measured by the two ultrasound methods. A lower degree of positive correlation was reported between the inner diameter of best-fit-ETT, and the inner diameter calculated by age-based formulas. Bland Altman's analysis showed agreement between best-fit-ETT outer diameter and epiphyseal diameter of the distal radius in both groups and with transverse cricoid diameter in the cuffed group, with no agreement with age-based formulas in either group. CONCLUSIONS: Both transverse cricoid diameter and epiphyseal diameter of the distal radius are reliable predictors of the size of best-fit-ETT pediatric endotracheal tube compared to age-based formulas. To save time and effort, we recommend the US measurement of the epiphyseal diameter of distal radius in the preoperative visit and documenting the predicted tube size with the preoperative assessments.

Radiological and Anatomical Evaluation of the Tracheal Morphology and Morphometry in Turkish Adults / Evaluación Radiológica y Anatómica de la Morfología y Morfometría Traqueal en Adultos Turcos

SUMMARY: The trachea is a tubular organ lying between larynx and lungs containing smooth muscle, membranes, and cartilage. This paper evaluated the dimessions of the trachea and main bronchi morphometry in healthy adults using Computed Tomography. This retrospective observational study was performed with 170 healthy adult subjects (89 females, 52.35 %; 81 males,47.65 %). The length of the trachea, the anteroposterior and transverse diameter of the trachea and the right and left main bronchi were measured. From these measurements, the trachea shape were calculated and four types of trachea were identified as circular, oval, horseshoe-shaped, and rectangular. All measurements were significantly higher in males than females (excluding tracheal bifurcation angle). According to the value obtained by dividing the anteroposterior by the width of the trachea, tracheal shapes are considered; the circular shape was seen 104 subjects (61.2 %), followed by oval type (34 subjects), horseshoe type (24 subjects) and rectangular type. (8 subjects). Also, the most frequently seen was circular type in both females and males. Hovewer, there was no significant difference between sex in terms of trachea shape. Additionally, a striking finding was that trachea morphometry and morphology showed the significance according to age dependent changes. Trachea measurements were affected several reasons such as used methods, age, sex, or race. This study has many clinical importance as it may reduce the risk of accidental damage to these area by clinicians such as cardiothoracic surgeons, anesthetist, or radiologist.

La tráquea es un órgano tubular que se encuentra entre la laringe y los pulmones y que contiene músculo liso, membranas y cartílago. Este trabajo evaluó las dimensiones de la tráquea y la morfometría de los bronquios principales en adultos sanos mediante Tomografía Computarizada. Este estudio observacional retrospectivo se realizó con 170 sujetos adultos sanos (89 mujeres, 52,35 %; 81 hombres, 47,65 %). Se midió la longitud de la tráquea, el diámetro anteroposterior y transversal de la tráquea y los bronquios principales derecho e izquierdo. A partir de estas mediciones, se calculó la forma de la tráquea y se identificaron cuatro tipos de tráquea: circular, ovalada, en forma de herradura y rectangular. Todas las mediciones fueron significativamente mayores en hombres que en mujeres (excluyendo el ángulo de bifurcación traqueal). Según el valor que se obtiene al dividir el anteroposterior por el ancho de la tráquea, se consideran las formas traqueales; la forma circular fue observada en 104 sujetos (61,2 %), seguida del tipo ovalado (34 sujetos), tipo herradura (24 sujetos) y tipo rectangular (8 sujetos). Además, el tipo más frecuente fue el circular tanto en mujeres como en hombres. Sin embargo, no hubo diferencias significativas entre sexos en términos de forma de la tráquea. Además, un hallazgo sorprendente fue que la morfometría y la morfología de la tráquea mostraron importancia según los cambios dependientes de la edad. Las mediciones morfométricas de la tráquea se vieron afectadas por varios motivos, como los métodos utilizados, la edad, el sexo o la raza. Este estudio tiene importancia clínica ya que puede reducir el riesgo de daño accidental por parte de médicos como cirujanos cardiotorácicos, anestesistas o radiólogos.

Challenging management of an enlarged tracheoesophageal fistula in an irradiated patient.

Speech restoration after total laryngectomy may be achieved in different ways, the gold standard being tracheoesophageal puncture (TPE) with the positioning of a speech prosthesis. TPE is not immune to complications, the most common of which being leakage through or around the prosthesis. When dealing with an enlarged tracheoesophageal fistula, the management can be either conservative or surgical. In the following case report, we present a particularly challenging case, in which every conservative strategies failed and a major surgery was required to close the fistula.