Tracheal and bronchial developmental disorders

Introduction to tracheal and bronchial developmental disorders The normal trachea is arranged horizontally from the throat to the bulge with 22 C-shaped cartilage rings. The opening of the cartilage ring is on the dorsal side. Even in the normal trachea, there are quantitative variations or Y-shaped cartilage rings. Because the incidence of trachea and bronchial malformation is low, some malformations are abnormalities of tracheal cartilage, which are often missed in routine examinations, and special examination methods are not widely used, so it is very rare and difficult to classify. basic knowledge The proportion of illness: 0.0035% Susceptible people: children Mode of infection: non-infectious Complications: tracheoesophageal fistula

Causes of tracheal and bronchial developmental disorders

(1) Causes of the disease

Common causes are embryonic stage due to a certain cause of trachea, bronchial development, or the development of the foregut into the trachea and esophagus, abnormalities in the origin of large bronchioles above the leaves can form different types and degrees of deformity.

(two) pathogenesis

The trachea and bronchus are not developed to form a lung deficiency. They may be bilateral, unilateral or one-leaf. At the 4th and 5th week of the embryo, the foregut is divided into two parts, that is, the digestive part on the dorsal side develops into an esophagus; The respiratory part located in the ventral side develops into the laryngotracheal tube, and the foregut develops into the trachea and esophagus. The ventral or dorsal displacement of the foregut causes the trachea, bronchial atresia or tracheoesophageal fistula to appear at birth. Fatal respiratory distress, 84% with other malformations, including: other bronchopulmonary malformations, cardiac malformations, vertebral malformations and gastrointestinal malformations, cervical or thoracic tracheal developmental disorders, terminal blind ends, or undeveloped lungs Tissue, forming a bronchial-like diverticulum. If the bronchus is connected to the normal lung segment or the lung lobes, it is called the tracheal bronchus. The lung tissue connected to the parabronchial tube is called the accessory lung. The accessory lung has the normal pulmonary artery and Intravenous supply, blind bronchus: refers to a tracheal-like blind process through the tracheal wall, the end of which ends in the lung parenchyma, forming a tracheal without respiratory function, the lesion remains the trachea Diverticulum.

Tracheal and bronchial developmental disorder prevention

Tracheal bronchial atresia for tracheal or bronchial angioplasty, the child still can not survive long-term after surgery, but there are reports of successful surgery. Patients with simple trachea and bronchial esophagus have a good prognosis, and the survival rate can reach 68%. However, patients with combined esophageal atresia have a poor prognosis, and the recurrence rate of postoperative esophageal bronchospasm is 3% to 22%. The prognosis of tracheal diverticulum and bronchial abnormal origin combined with infection surgery is better.

Tracheal and bronchial developmental complications Complications of tracheoesophageal fistula

Often accompanied by other malformations: tracheoesophageal fistula and abnormalities in the heart and genitourinary system.

Symptoms of tracheal and bronchial developmental disorders Common symptoms, pronunciation disorder, pulmonary infection, cyst, shortness of breath, difficulty breathing

The clinical manifestations of different malformations are not the same. Common malformations are:

1. Trachea, bronchial atresia are very rare, often accompanied by other malformations: tracheoesophageal fistula and heart, abnormalities of the genitourinary system, Floyd et al. divided these malformations into three subtypes, type I: 10%, Including the tracheal part of the atresia, the distal trachea is a short segment of the normal trachea connected to the anterior wall of the esophagus; type II: 59%, complete trachea is not developed, the bronchi and carina are normal, the carina is connected with the esophagus; type III: accounted for 31 %, the trachea is completely undeveloped, and the bronchus originates from the esophagus. It has been reported that according to the diseased trachea, the degree of bronchial development, and the presence or absence of esophageal tracheal fistula, there are 7 types (Fig. 1). The four common types are listed. The most common type is The trachea is completely missing between the larynx and the esophagus, which accounts for about 50% of the type, and only 5% to 10% of other types.

Congenital bronchial atresia or stenosis may involve the lobes of the leaves, segments or sub-segments, which occur at or near the proximal end, and the posterior bronchus of the left upper lobe is most common. The lesion is segmental, and the bronchial tree outside the lesion, Whether it is the distal or proximal bronchus, the morphology and structure are normal or close to normal, the typical manifestations are: 1 or more bronchial mucus, and dilatation (mucus cyst), in most cases, the resected specimen shows far, The proximal bronchus is not connected, and occasionally the sputum or fibrous cord is separated.

The average age of diagnosis of congenital bronchial stenosis or atresia is 17 years old, nearly 2/3 is male, usually asymptomatic, about 20% of patients have a history of recurrent pulmonary infection, and larger tracheal stenosis often occurs in infancy It is manifested as respiratory distress, wheezing or recurrent pneumonia. The child is often premature or immature. After birth, there is cyanosis and no crying. The tracheal intubation can not reach the vocal cords. The esophagus can temporarily improve the ventilation. ,

2. Bronchoconstriction is a rare congenital bronchial stenosis. The most common bronchial stenosis is secondary right main bronchial stenosis. It is an incorrect or frequent sucking during long-term mechanical assisted ventilation in infants, causing inflammation changes and granulation tissue in the main The bronchial opening is caused by accumulation, and the clinical manifestation is difficulty in breathing. If the tracheal stenosis is combined, there may be a dysphonic disorder, and the body may have wheezing.

3. Tracheal diverticulum congenital trachea, bronchospasm is relatively common, the most common tracheal diverticulum, may be derived from the diagnosis and treatment of the same tracheal diverticulum (Figure 2).

The tracheal diverticulum is located on the right side of the trachea 1 to 3 cm trachea, often single, asymptomatic, can retain foreign bodies, more in the operation, bronchial examination or autopsy accidental discovery, bronchoscopy can be diagnosed, no special treatment, no symptoms May cause recurrent pneumonia, wheezing or neonatal respiratory distress due to parabronchial stenosis or other lung malformations.

4. Abnormalities of bronchial origin The origin of bronchial abnormalities refers to abnormalities of the origin of large bronchioles above the leaves. It is extremely rare, and the bronchial origin of the lungs or segments is abnormal. It is more common and is considered as anatomic variation. It should be noted during bronchoscopy and surgery. No other Clinical significance (Figure 3).

There are 4 kinds of main bronchial abnormalities: 1 more than 1 (occasionally no) lobes of the lung lobe or segment, such as double right upper lobe bronchus; 2 ipsilateral ectopic bronchus: abnormal origin of leaf bronchus, the most common is the right upper lobe bronchus originating from the trachea, forming Tracheal trigeminal branch, called the upper bronchial artery; 3 ectopic bronchial bronchi: this type of bronchial bifurcation and lung lobular ectopic to the contralateral lung, such as: the lower right or middle bronchus across the mediastinum originates from the left main bronchus , called bronchial bridge, can be a single deformity, but also can coexist with heart, spleen and other deformities, such as: bronchial bridge can be accompanied by left pulmonary artery suspension and tracheal stenosis; 4 extra bronchial: it usually starts from the right main bronchus or the middle The lower wall of the dry bronchus.

Abnormalities of bronchial abnormalities and abnormal branches are often asymptomatic and have no obvious clinical significance, but occasionally secondary recurrent pulmonary infections, etc.

Esophageal angiography can be seen in part of the lung tissue through the bronchial structure and esophageal traffic, the abnormal origin of the lobes or segments of the esophagus (the esophagus bronchus) can be the right or left lung, but also the upper or lower lobe, to the affected lobe There are various conditions of blood supply, some of the lungs are normal lung blood supply, while others are for systemic blood supply, leaf type and intralobular lung isolation (defined as abnormal blood supply and no bronchial traffic) with esophagus or Other foregut-derived organ traffic, therefore often causes confusion in the definition of nouns, so some of these malformations are referred to as congenital bronchopulmonary anterior intestinal malformations.

5. Trachea, bronchial esophageal fistula accounted for 1/800 to 1/5000 of the born baby, simple tracheal esophageal fistula is rare, accounting for about 4% of tracheal and esophageal malformations, and tracheal esophageal fistula with esophageal atresia is more common, about Accounted for 88% of tracheal and esophageal malformations.

Divided into 5 main types (Figure 4): 1 short closed esophagus, distal esophagus from the lower trachea, this type is the most common, accounting for more than 80%; 2 esophageal atresia without tracheoesophageal fistula, this type of trachea development is normal 3, there is esophageal tracheal fistula, and no esophageal atresia; 4 esophageal atresia, with closed mouth esophageal tracheal fistula; 5 esophageal atresia, with trachea and atresia and anal esophageal fistula.

Bronchial esophageal fistula formed between the esophagus and the right main bronchus is rare, and it is also divided into two types of clinical pathology: with or without esophageal atresia, the former is the blind end, is the most common type.

Low birth weight is a high risk factor for this disease. 70% are found in low birth weight children at birth. Most of them are premature because of other diseases. Males are slightly more than females. After birth, they can have excessive saliva, white foam, etc. , vomiting, difficulty breathing, cyanosis, etc., after the cessation of eating, the above performance is significantly reduced, such as treatment is not timely, infants and young children may cause aspiration pneumonia due to oral secretions, eating or reflux of stomach contents, fever, shortness of breath, dehydration, etc. In severe cases, death may occur due to pulmonary complications. If the term infant is simple, 100% can survive.

Tracheal and bronchial developmental disorders

1. X-ray examination of children with tracheobronchial atresia X-ray chest showed: close to the hilar, and the tip of the triangle-like lesion area pointing to the hilar, showing a high translucent and linear, oval, branched mucinous cystic manifestations The surrounding normal lung parenchyma and mediastinum will be compressed, displaced, abnormal bronchial origin, stenosis and tracheal diverticulum in children with X-ray manifestations of chronic lung infection or emphysema signs, tracheal esophageal fistula can also see gastric or intestinal gas cut back.

2. CT examination can show the characteristics of central cystic mucinous cyst of bronchial atresia, in order to identify bronchogenic cysts or lobular emphysema. Three reconstruction CT examination is the best means to confirm the extent and extent of bronchial stenosis, for trachea In the diverticulum, CT can diagnose the para-bronchus, and the coronal CT can better diagnose the para-bronchus without bronchography.

3. Bronchoscopy can directly see the diverticulum in the tracheal diverticulum, and can understand the number and size of the diverticulum; tracheoesophageal fistula can see the fistula, bronchoscopy can be seen in different types of major bronchiole origin.

4. Contrast examination has statistical data on the origin of bronchial abnormalities for bronchography, 7/1500 can be seen in the left posterior segment from the left main bronchus, 4/7 of which have tracheal obstruction, tracheal diverticulum can be seen by tracheal angiography, and the trachea is evaluated. Bronchial tree, tracheal esophageal fistula angiography method is to first place the stomach tube, more than 10 ~ 12cm encountered resistance, then injected with lipiodol, angiography, you can confirm the diagnosis.

Diagnosis and identification of tracheal and bronchial developmental disorders

According to the symptoms of respiratory distress and recurrent pneumonia in infants and young children, combined with X-ray, angiography and CT examination, early diagnosis of tracheobronchial developmental disorders has no difficulty.

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