Cicatricial and expiratory tracheal stenosis
The trachea is a cartilaginous tubular organ through which air is inhaled and exhaled. It is located below the larynx and passes into the main bronchi. Narrowing (stenosis) of the trachea can develop with cicatricial changes in the tracheal wall, with neoplasms of the thyroid gland, compression of the trachea from the outside, with tumors of the meeting. Cicatricial and expiratory tracheal stenosis is distinguished.
Cicatricial tracheal stenosis
It is characterized by the replacement of tracheal wall structures with scar tissue, as well as loss of tracheal skeleton. The most common cause of this disease is prolonged pressure exerted on the wall of the trachea by the cuff of an endotracheal tube or tracheostomy cannula during prolonged mechanical ventilation. All this leads to impaired blood circulation in the tissues and, accordingly, to the growth of granulations. If the trachea is damaged, a purulent-necrotic process may develop.
It is the inflammatory process that plays an essential role in the development of tracheal stenosis. In rare cases, its cause cannot be determined, and then it is classified as idiopathic. Usually stenosis of this etiology develops in middle-aged women. A dense keloid scar is 1-3 cm long and is located in the adventitia (upper membrane) of the upper third of the trachea.
The most complete classification of cicatricial tracheal stenosis was proposed by Doctor of Medical Sciences, Professor V. D. Parshin, according to which stenoses are divided:
1. By localization. They can develop in the larynx with damage to the vocal folds and subglottic region, in the cervical trachea, in the upper thoracic, middle thoracic and supra-bifurcated trachea. These can be combined lesions.
2. By etiology. Stenoses can be idiopathic, post-tracheostomy, post-traumatic, and post-intubation.
3. By prevalence. There are limited stenoses (up to 2 cm long) and extended (over 2 cm).
4. By the degree of narrowing. 1 degree of stenosis - narrowing of the lumen of the trachea by 1/3 of the airway diameter, 2 degree - narrowing from 1/3 to 2/3 of the diameter, 3 degree - narrowing by more than 2/3 of the diameter.
5. Anatomical form of the lesion. It can be circular narrowing, narrowing of the anterolateral walls, atresia.
6. According to the condition of the tracheal walls. Stenosis with and without tracheomalacia is distinguished. Tracheomalacia is an underdevelopment of the cartilaginous skeleton and muscle tissue of the trachea.
7. By the presence of a tracheostomy. A tracheostomy is an artificial opening inserted into the outer region of the neck for a person to breathe.
Expiratory tracheal stenosis
Functional narrowing of the trachea and main bronchi is called expiratory stenosis. It is characterized by excessive immersion of the atonic membranous film into the lumen of the trachea during exhalation and coughing. The main bronchi are often affected. Distinguish between primary and secondary expiratory narrowing (stenosis) of the trachea. Primary expiratory stenosis is the result of damage to the nerve elements of the tracheal wall by viruses or bacterial toxins in acute respiratory infections (acute respiratory diseases), influenza. Secondary stenosis develops with pulmonary emphysema.
Most often, the disease is observed equally often in both men and women after 30 years. Clinically, it manifests itself as shortness of breath, dry barking, rattling or "pipe" cough, attacks of suffocation. Sometimes a coughing fit may be accompanied by dizziness or vomiting. Asthma attacks can lead to fainting, and shortness of breath is poorly controlled by bronchodilators.
If tracheal stenosis (tracheostenosis) occurs in the antenatal period, then it can be:
· Compression, i.e. due to pressure on the trachea of an overgrown thyroid gland, mediastinal tumor or congenital cyst;
· Obturating, i.e. arising in the presence of any obstacle inside the trachea itself. This is possible with the pathological development of cartilage, as a result of which part of the trachea takes the form of a narrow tube without a membranous wall.
Diagnosis of tracheal stenosis
According to clinical manifestations, 3 stages of tracheal stenosis are distinguished:
1. Compensated stenosis - most often there are no symptoms. The inner diameter of the trachea is 0.6 cm or more.
2. Subcompensated stenosis - its symptoms are shortness of breath, cough, cyanosis, stridor, impaired ventilation and hemodynamic disorder even with little physical exertion. The inner diameter of the trachea in this case is 0.3-05 cm.
3. Decompensated stenosis - it is characterized by infectious complications, impaired breathing and hemodynamics of the patient in a calm state. The inner diameter of the trachea is only 0.3 cm or less.
With tracheal stenosis, the patient's head is usually tilted forward, the larynx is motionless (even with increased breathing), the voice does not change or changes slightly.
In the diagnosis of tracheal stenosis, mainly endoscopic and X-ray examinations are used. The degree of patency of the trachea is determined according to the indications of pneumotachography. Often, shortness of breath and cough observed in a patient are associated with lung disease, due to which, in many cases, tracheal stenosis is diagnosed in a later period.
Treatment of cicatricial and expiratory tracheal stenosis
Treatment of cicatricial stenosis includes endoscopic (through a bronchoscope) and open surgery to expand and restore the lumen of the trachea. Endoscopy removes scar tissue and passes a conical or cylindrical dilator (dilator) through the narrowed trachea. A stable positive effect after such treatment is observed in most patients with tracheal stenosis. In case of relapse of the disease, the patient is given an endoprosthesis for a long time or open surgery is performed.
Endoscopy and conservative treatment are used to treat expiratory tracheal stenosis. To alleviate the condition of patients, reduce coughing and facilitate breathing, they are advised not to pills (they are ineffective), but to exercise delayed exhalation with artificial resistance. The exhalation is carried out with closed lips or through a narrow tube. In the early stages, expiratory stenosis can often be eliminated by intensive treatment of tracheobronchitis.
A new method for treating expiratory stenosis of the trachea and main bronchi is the introduction of a sclerosing mixture into the retrotracheal space. This operation is performed during bronchoscopy under local or general anesthesia. A lasting positive effect is achieved in most cases of primary expiratory stenosis and in half of cases of secondary stenosis. Open surgery for expiratory tracheal stenosis is rarely used.
Article author: Mochalov Pavel Alexandrovich | d. m. n. therapist
Education: Moscow Medical Institute. IM Sechenov, specialty - "General Medicine" in 1991, in 1993 "Occupational Diseases", in 1996 "Therapy".