Lung underdevelopment or hypoplasia
Introduction
Introduction to lung non-development or hypoplasia Congenital lung non-development and pulmonary hypoplasia are caused by impaired lung bud development during embryonic development. The incidence rate is low, and many of them were found at autopsy. This year, due to radiation and CT, MRI and other technologies, the diagnosis rate of this disease has been significantly improved. basic knowledge The proportion of illness: 0.001% Susceptible people: more common in the embryonic period Mode of infection: non-infectious Complications: chronic bronchitis, bronchiectasis
Cause
Lung non-development or hypoplasia
(1) Causes of the disease
Pulmonary bud development at a certain stage during embryonic development leads to lung non-development and lung hypoplasia, most of which are concurrent with other developmental defects, more common with tracheal, bronchial and pulmonary dysplasia and absence, spinal dysplasia, and The abdominal organs enter the pleural cavity through the thoracic and peritoneum. These deformities compete with the lungs for the pleural space. 50% to 80% of infants with congenital diaphragmatic hernia die from pulmonary failure, mainly due to congenital pulmonary hypoplasia.
(two) pathogenesis
Lung non-development or lung hypoplasia can be divided into the following pathological types:
1. Lung dysplasia is a developmental disorder of the lung parenchyma. Common types include undeveloped lung tissue with congenital diaphragmatic hernia, absent pulmonary artery, and spherical lung with bronchial malformation.
2. The absence of a lobe or a leaf is absent, usually the right middle lobe and the right lower lobe are absent, the mediastinum is displaced to the affected side, and the remaining lungs of the affected side are combined with other malformations.
3. Unilateral lung deficiency, such as due to one side of the lung bud development disorder, can be bronchial atresia, no lung tissue and pulmonary vessels at the distal end; another part of the manifestations of bronchoconstriction and emphysema of the distal lung tissue, due to gas The lateral bronchus enters the lung tissue lacking pulmonary blood vessels and the main bronchus is absent. The secondary lung is absent. The left side is significantly more than the right side. Because the residual lung ventilation can not be compensated, the child mostly died in infancy. A few still live to be over 60 years old without obvious clinical symptoms.
4. Lung lung deficiency, such as embryonic lung buds are not developed, the incidence is rare, the fetus is more complicated with the heart and other organ deformities, most of them die abortion in the uterine cavity, a few may have respiratory struggle after birth, can not sustain life.
Prevention
Lung development or hypoplasia prevention
There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.
Complication
Lung non-development or hypoplasia complications Complications chronic bronchitis bronchiectasis
Survivors often have poor growth and development, leaving chronic asthma, pulmonary fibrosis, pulmonary dysfunction, pulmonary heart disease and neurological complications such as mental retardation and cerebral palsy.
During the developmental period of mental retardation, the general intellectual function is significantly lower than the same age level, and the same amount is accompanied by a group of diseases with adaptive behavioral defects. IQ (IQ) is lower than the population mean of 2.0 standard deviation (the IQ of the population is set at 100, the IQ value of a standard deviation is 15), and the general IQ below 70 (or 75) is that the intelligence is significantly lower than the average.
Symptom
Lung non-development or hypoplasia symptoms Common symptoms Thoracic deformity Breath sounds rough hemoptysis Breathing sounds weakened vocal dyspnea
Recurrent respiratory infections are the main cause of treatment. Patients with unilateral pulmonary hypoplasia often have mild dyspnea, poor physical strength and endurance. Some patients may have hemoptysis due to collateral circulation from the systemic circulation. Patients with respiratory tract infections have increased difficulty in breathing and cyanosis. Thick breath sounds, growth retardation, accompanied by heart, bone or other organ deformities, may have corresponding symptoms, the patient's thorax is often without deformity, bilateral symmetry or near symmetry, weak respiratory motion on the affected side, weakened breath sounds Or disappear, percussion can be real or over-sound, no specificity, often associated with chest deformity, the patient has fewer symptoms, the patient has less clinical symptoms, and the patient has only reduced respiratory sounds on the affected side. It is extremely easy to miss the examination without X-ray examination. If the above-mentioned type is accompanied by a lung infection, the breathing sound may be rough and arpeggio.
Recurrent respiratory infections of unknown origin should consider whether there is congenital pulmonary hypoplasia. The diagnosis must be very careful. X-ray examination is the first choice. The bronchography or pulmonary perfusion scan can not confirm the cause.
Examine
Examination of lung non-development or hypoplasia
1. X-ray examination of one side of the lung is not developed on the X-ray chest radiograph, the density of the chest cavity is uniform and dense, and there is a lack of inflated lung tissue and traces of bronchial shadow and vascular texture. The heart and mediastinum are moved to the affected side. The lateral sacral surface is unclear, and the contralateral normal lungs have different degrees of compensatory emphysema, so that the transverse sputum is lowered, the sacral surface is flattened, and the over-expanded lung can form a mediastinum, if at the same time, the spine is half. Vertebral malformation is very helpful for diagnosis. Another part of lung hypoplasia can show lung tissue aeration on chest X-ray, but the lung texture is sparse. In contrast, it is sometimes mistaken for contralateral bronchial inflammation or bronchiectasis. pay attention.
2. Bronchography can show the absence of the main bronchus on the affected side, the trachea seems to be directly connected to the other main bronchus, or the main bronchus is dysplastic, or the number of bronchial branches is sparse. Pulmonary angiography can be seen in the pulmonary artery trunk of the affected side. Dysplasia or lack of help helps to determine the diagnosis.
3. Pulmonary arterial perfusion scan of the affected side showed a reduction or significant reduction in pulmonary blood flow.
Diagnosis
Diagnosis and identification of lung non-development or hypoplasia
1. Bronchiectasis shows an increase in the transparency of lung tissue in the X-ray chest radiograph, the lung texture is sparse, and it is easy to be confused with the lobular hypoplasia. The bronchography can confirm the diagnosis.
2. Ordinary bronchial inflammation and pulmonary hypoplasia combined with pulmonary infection identification X-ray examination is not easy to identify, feasible pulmonary angiography.
