Differences in Flexible and Rigid Bronchoscopy for Assessment of Tracheomalacia.

OBJECTIVES/HYPOTHESIS: Both flexible and rigid bronchoscopy can be used to assess tracheomalacia; however, there is limited evidence comparing the two techniques. The objective of this study was to compare flexible and rigid bronchoscopy for evaluating the location and severity of tracheomalacia in children. STUDY DESIGN: Retrospective case series. METHODS: This was a retrospective study of children with both flexible and rigid bronchoscopy under the same sedation. All bronchoscopies were reviewed by three bronchoscopists for the location and severity of tracheomalacia. The location of collapse was defined as upper, middle, or lower trachea, and the severity of collapse was defined as none (0%-25% collapse), mild/moderate (26%-75% collapse), and severe (>75% collapse). RESULTS: Twenty-one patients were recruited for this study with a variety of neonatal respiratory diseases. There was 94% agreement (κ = 0.64) for assessment of tracheomalacia in the upper trachea. However, agreement was only 75% (κ = 0.50) in the middle trachea and 76% (κ = 0.52) in the lower trachea. In the subset of patients without tracheostomy, agreement improved to 100%, 88%, and 82% for the upper, middle, and lower trachea, respectively. There was poor correlation for tracheomalacia severity in the middle trachea (ρ = 0.30, P = .2) and moderate in the lower trachea (ρ = 0.63, P = .002). CONCLUSIONS: Although there is moderate agreement between flexible and rigid bronchoscopy for evaluating the presence of tracheomalacia, there can be differences in the two techniques, particularly when assessing severity of airway collapse. Future studies will be needed to understand factors that result in the discordance of flexible and rigid bronchoscopy for assessing airway dynamics. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:201-204, 2021.

Two males with sick sinus syndrome in a family with 0.6 kb deletions involving major domains in MECP2.

Mutations in methyl-CpG-binding protein 2 (MECP2) in males can lead to various phenotypes, ranging from neonatal encephalopathy to intellectual disability. In this study, using Nord's method of next-generation sequencing in three siblings, we identified a 0.6 kb deletion involving the transcriptional repression domain (TRD). Two males and one female had intellectual disability and apnea, but none met the criteria of Rett syndrome. Both males had sick sinus syndrome and severe tracheomalacia that resulted in early death. The mother, with skewed X-inactivation, had no symptoms. Therefore, this mutation is pathological for both males and females, resulting in sick sinus syndrome and severe tracheomalacia with strong reproducibility in males. Deletions involving major domains in MECP2 can result in a severe phenotype, and deletion of the TRD domain can cause severe autonomic nervous system dysregulation in males in these cases.

Difficulty in tracheal extubation followed by tracheal collapse after balloon dilatation for tracheal stenosis therapy: A case report.

RATIONALE: Tracheobronchomalacia (TBM) refers to the weakening trachea or the trachea loss of structural integrity of airway cartilaginous structures. It causes tracheal stenosis, resulting in significantly high rates of mortality. Bronchoplasty by high-pressure balloon dilation under general anesthesia is a simple but effective and safe method to treat tracheobronchial stenosis. However, recurrent postoperative dyspnea after extubation due to tracheal collapse is still a challenge for anesthetists. PATIENT CONCERNS: A 52-year-old man weighing 72 kg was scheduled for balloon dilatation surgery under general anesthesia because of breathing difficulties caused by tracheal stenosis. His previous medical history included rheumatoid arthritis, obstructive sleep apnea syndrome (OSAS), chronic bronchitis and a history of tracheal intubation. Laryngeal computerized tomography confirmed the stenosis at the level of thyroid gland. DIAGNOSIS: The tracheal collapse after balloon dilatation for tracheal stenosis therapy. INTERVENTIONS: Postoperatively, the patient presented with more serious and repetitive symptoms of dyspnea after extubation when compared to that before treatment. So, we had to re-insert the laryngeal mask airway (LMA), and exclude some anesthesia-associated factors, such as laryngospasm, bronchospasm and so on. After a series of treatments, we ultimately found the cause in time (the airway collapsed), and succeeded in tracheal extubation after the stent was inserted. OUTCOMES: The patient recovered well and reported high satisfaction with anesthesia management. LESSONS: In such an emergency even, the anesthesiologist should take valuable treatments to ensure the patient's effective ventilation. If the anesthesia-related factors can be eliminated, tracheomalacia or airway collapse should be considered whenever dyspnea occurs in the patients who unexpectedly fail to be extubated.

Computational modeling of airway instability and collapse in tracheomalacia.

BACKGROUND: Tracheomalacia (TM) is a condition of excessive tracheal collapse during exhalation. Both acquired and congenital forms of TM are believed to result from morphological changes in cartilaginous, fibrous and/or smooth muscle tissues reducing airway mechanical properties to a degree that precipitates collapse. However, neither the specific amount of mechanical property reduction nor the malacic segment lengths leading to life threatening airway collapse in TM are known. Furthermore, the specific mechanism of collapse is still debated. METHODS: Computational nonlinear finite element models were developed to determine the effect of malacic segment length, tracheal diameter, and reduction in tissue nonlinear elastic properties on the risk for and mechanism of airway collapse. Cartilage, fibrous tissue, and smooth muscle nonlinear elastic properties were fit to experimental data from preterm lambs from the literature. These elastic properties were systematically reduced in the model to simulate TM. RESULTS: An intriguing finding was that sudden mechanical instability leading to complete airway collapse occurred in airways when even a 1 cm segment of cartilage and fibrous tissue properties had a critical reduction in material properties. In general, increased tracheal diameter, increased malacic segment length coupled with decreased nonlinear anterior cartilage/fibrous tissue nonlinear mechanical properties increased the risk of sudden airway collapse from snap through instability. CONCLUSION: Modeling results support snap through instability as the mechanism for life threatening tracheomalacia specifically when cartilage ring nonlinear properties are reduced to a range between fibrous tissue nonlinear elastic properties (for larger diameter airways > 10 mm) to mucosa properties (for smaller diameter airways < 6 mm). Although reducing posterior tracheal smooth muscle properties to mucosa properties decreased exhalation area, no sudden instability leading to collapse was seen in these models.

Use of a Nitinol Wire Stent for Management of Severe Tracheal Stenosis in an Eclectus Parrot (Eclectus roratus).

A 25-year-old, female eclectus parrot (Eclectus roratus) presented for dyspnea 3 weeks after anesthesia and surgery for egg yolk coelomitis. Radiography, computed tomography, and tracheoscopy revealed multiple tracheal strictures spanning a length of 2.6 cm in the mid to distal trachea. Histopathologic examination revealed mild fibrosis, inflammation, and hyperplasia consistent with acquired tracheal strictures. Tracheal resection was not considered possible because of the length of the affected trachea. The strictures were resected endoscopically, and repeated balloon dilation under fluoroscopic guidance over the course of 10 months resulted in immediate but unsustained improvement. Computed tomography was used to measure the stenotic area. A 4 × 36-mm, custom-made, nitinol wire stent was inserted into the trachea under fluoroscopic guidance. After stent placement, intermittent episodes of mild to moderate dyspnea continued, and these responded to nebulization with a combination of saline, acetylcysteine, and dexamethasone. Multiple attempts to wean the patient off nebulization therapy and to switch to a corticosteroid-free combination were unsuccessful. The parrot eventually developed complications, was euthanatized, and necropsy was performed. Histologically, the tracheal mucosa had widespread erosion to ulceration, with accumulation of intraluminal exudate and bacteria, severe degeneration of skeletal muscle and tracheal rings, prominent fibrosis, and mild to moderate, submucosal inflammation. Clinicopathologic findings in this case suggested tracheomalacia, which has not been previously described in birds. Custom-made tracheal stents can be used for severe tracheal stenosis in birds when tracheal resection and anastomosis is not possible. Complications of tracheal stent placement in birds may include tracheitis and tracheomalacia. To our knowledge, this is the first report of tracheal stent placement in an avian species.

Diagnosis and conservative management of late tracheotomy complications in chronic ventilator-dependent patients.

BACKGROUND: Complications associated with long-term tracheotomy are obstruction of the distal end of the tube by granulation tissue and tracheomalacia. These complications have traditionally been surgically treated. METHODS: Prospective study in a chronic ventilator-dependent division, including 234 consecutive patients with tracheotomy and mechanical ventilation. Endoscopic evaluation was performed in patients in whom there was respiratory distress with difficulty in passing a suction catheter through the tube, and/or increased inspiratory resistance and increased peak inspiratory pressure. RESULTS: Nineteen patients were diagnosed with granulation or tracheomalacia. Two patients were treated by surgical removal of the obstructing tissue. Nonsurgical patients were conservatively managed with symptoms' resolution by bypassing the pathology with a longer tube than the previous one or by an adjustable flange tube under endoscopic visualization, with a median symptom-free period of 433 days (range, 55-1230 days). CONCLUSION: In nonsurgical candidates, insertion of a longer tube is a conservative and feasible long-term treatment.

What's in a name? Expiratory tracheal narrowing in adults explained.

Tracheomalacia, tracheobronchomalacia, and excessive dynamic airway collapse are all terms used to describe tracheal narrowing in expiration. The first two describe luminal reduction from cartilage softening and the latter refers to luminal reduction from exaggerated posterior membrane movement. Expiratory tracheal narrowing is a frequent occurrence that can cause symptoms of airway obstruction, such as dyspnoea, wheeze, and exercise intolerance. The accurate diagnosis and quantification of expiratory tracheal narrowing has important aetiological, therapeutic, and prognostic implications. The reference standard for diagnosis has traditionally been bronchoscopy; however, this method has significant limitations. Expiratory tracheal disorders are readily detected by four-dimensional dynamic volume multidetector computed tomography (4D-CT), an emerging, non-invasive method that will potentially enable detection and quantification of these conditions. This review discusses the morphological forms of expiratory tracheal narrowing and demonstrates the utility of 4D-CT in the diagnosis, quantification, and treatment of these important conditions.

Malacia, inflammation and bronchoalveolar lavage culture in children with persistent respiratory symptoms.

In children with persistent respiratory symptoms despite regular anti-asthma inhalation treatment, diagnostic investigations to exclude underlying disease are warranted. 124 children were prospectively enrolled, and 24-h oesophageal pH measurement and fibreoptic bronchoscopy with bronchoalveolar lavage (BAL) were performed. BAL fluid (BALF) was processed for neutrophil counting and bacterial culture. Inflammation of the respiratory mucosa was assessed. A structural abnormality of the central airways was found in 47% of subjects (40% females). In 19% of subjects, neither anatomical anomalies nor inflamed respiratory mucosa were observed, whereas in 64%, definite macroscopic mucosal inflammation was observed. Inflammation of the respiratory mucosa was associated with a significantly higher percentage of neutrophils in the BALF: median (interquartile range) 48 (14-82)% compared with 7 (0-16)% (p<0.025). A positive BALF culture was found in 62% of the infants with mucosal inflammation compared with 25% in the group without inflammation (p<0.016). 56% of the BALF samples were positive for bacterial culture. In children with persistent respiratory symptoms, nearly half have anatomical anomalies of the central airways. In 62% of the children with mucosal inflammation, a positive BAL culture and a significantly higher percentage of BALF neutrophils were detected.

Tracheomalacia after reoperation for an adenomatous goiter located in a unique position.

Tracheomalacia after thyroidectomy is a life-threatening situation. However, it is difficult to predict postoperative tracheal obstruction with certainty. A case of a 74-year-old woman with a long-standing adenomatous goiter (98 g) is reported. She had undergone partial right lobe thyroidectomy 54 years earlier. After total thyroidectomy, she was reintubated and required a tracheostomy because of tracheomalacia. The right residual thyroid tumor weighed only 5 g, but it extended to the retrotracheal space. Because the right lobe had stretched the membranous wall of the trachea over a long period of time, the tracheal lumen was thought to have collapsed because of loss of the foundation of the tracheal cartilage (the residual right lobe) along with the supportive surrounding tissue (the left lobe) after surgery. The present case suggests that the occurrence of tracheomalacia could be attributed to reoperation and retrotracheal extension. Thus far, six preoperative predictive factors for the development of severe postoperative respiratory obstruction have been reported: goiter for more than 5 years, preoperative recurrent laryngeal nerve palsy, significant tracheal narrowing and/or deviation, retrosternal extension, difficult endotracheal intubation, and thyroid cancer. Two more factors, reoperation and retrotracheal extension of tumor, may also be risks for airway obstruction after thyroidectomy.

[Retrotracheal left pulmonary artery: case report with an embryologic and anatomic update]. / Artère pulmonaire gauche rétrotrachéale : mise au point embryologique et anatomique.

The accidental discovery of a retrotracheal left pulmonary artery in a 4-month-old infant encouraged us to review the various embryologic theories concerning this very rare anomaly and perform an anatomic update in order to better define surgical treatment. Nathan underwent surgery for a bilateral inguinal hernia at the age of 4 months. The postoperative period was marked by malaise associated with dyspnoea, stridor, tachycardia and sweating. A X-ray of the thorax, oesophageal transit and angio scan presented an intertracheo-oesophageal left pulmonary artery and a reimplantation of the left pulmonary artery was successfully performed. A retrotracheal left pulmonary artery is a very rare malformation. From development of pulmonary vascularisation, three embryologic theories have been advanced to explain this anomaly. From an anatomic point of view, Landing et al. proposed in 1982 a classification system of retrotracheal left pulmonary artery. Today, current radiological techniques not only provide a precise diagnosis but also make it possible to define appropriate care for the different types of this malformation.

Utility of virtual bronchoscopy in congenital tracheomalacia.

Utility of virtual bronchoscopy was evaluated in a case of congenital tracheomalacia by comparing virtual bronchoscopic images with those of fiberoptic bronchoscopy. Results indicate that virtual bronchoscopy is useful in diagnosing stationary lesions. However, its diagnostic value is inferior to that of fiberoptic bronchoscopy for mobile lesions, in that virtual bronchoscopy does not permit dynamic images. We recommend that the institutions, where fiberoptic bronchoscopy is available, should perform virtual bronchoscopy in parallel to explore its utility.