Tuesday, April 2, 2013

Williams– Campbell Syndrome (Generalized Congenital Bronchiectasis)

In 1960, Williams and Campbell have described the clinic and radiological picture of peculiar generalized bronchiectasis due to congenital hypoplasia of the bronchial branches. Due to the structural deficiency in patients with bronchial tree during inspiration there is arising pathological balloon expansion of subsegmental bronchi, falling on the exhale.

                  Bronchiectasis are the pathologically enlarged sections of the bronchi, in the mucous membrane of which chronic inflammation develops, usually with purulent exudation and sclerotic changes in the peribronchial tissues.
                    
                  Syndrome is based on genetically inferiority of bronchial wall due to the bronchial cartilage defect. It arises under the influence of various pathological processes on formation of lungs in the embryonic period.
                    The morphological defect is associated with segmental and subsegmental bronchi, most of the lower lobes. As with lobar emphysema, lung tissue is air. Therefore it is believed that these two diseases occur as a result of one and the same process. It occurs with a frequency of 1:100 000.
         The clinical picture is the bronchial obstruction and bronchopulmonary infection. Usually in the first year of life an acute pneumonia occurs, and then eventually a chronic bronchopulmonary process is formed. Objectively chest is like hump.The cough is resistant with shortness of breath. At percussion of the lungs there is bandbox sound, at auscultation– dry and moist rales of various sizes. Phalanges and nails become "drumsticks", "hour-glass", a violation of external respiration is present.
                Radiological findings in the lungs are increased pulmonary pattern, the phenomenon of emphysema. At bronchography there are determined generalize bronchiectasis with balloon expansion during inspiration and collapse (by closing the walls) during expiration.


The scheme of the diameter changes of the bronchi at Williams - Campbell syndrome on inhalation (a) and expiration (b).


                         
Bronchogram of the left lung of the child with the Williams-Campbell syndrome.

            Prognosis is poor. Progression of syndrome leads to cardiopulmonary failure, which is the cause of death.
            Treatment is conservative.

                          Congenital lobar emphysema
         Congenital lobar emphysema (congenital localized emphysema, gigantic emphysema, tense emphysema) is characterized by stretching of the parenchyma of the lung lobe or a segment with manifestation mainly in early childhood. This anomaly is rare, but late diagnosis quickly leads to death of newborns.
          This disease is characterized by narrowing of the bronchus, it aplasia, dysplasia, and hypertrophy of the mucosa with the formation of folds, which act as valves. Amount of air, which gets into the lungs is more than that which gets out (valve mechanism).
             Massive overinflation of one or more lung lobes occurs postnatally in congenital lobar emphysema. Causes include intrinsic absence or abnormality (bronchomalacia) of cartilaginous rings or external compression by a large pulmonary artery. (Compression of the cartilage usually leads to malacia.) Hyperexpansion of a pulmonary lobe is present after birth when, with negative inspiratory pressure, air can enter the lung. However, the air cannot exit easily because positive pressure causes the softened airway to collapse. The remaining normal lung is then compressed.
             Causes of congenital lobar emphysema include bronchial cartilage deficiency, extrinsic compression by a bronchogenic cyst, a large pulmonary artery, or mucus plugs. Lobar overdistention and airtrapping lead to compressive changes in the rest of the lung.
                                                 
                   Congenital lobar emphysema primarily involves the upper lobes. The left upper lobe is involved in 41% of patients; the right middle lobe, in 34%; and the right upper lobe, in 21%. Involvement of the lower lobes is rare, occurring in fewer than 5% of patients. Congenital cardiac anomalies may be present in as many as 10% of patients. Lesions most commonly occur in whites, in male individuals (male-to-female ratio, 3:1), and in young infants.

                                                     Clinic
                          Most patients with congenital lobar emphysema present before 6 months of life. Neonates may present with mild-to-moderate respiratory distress. Mediastinal shift may be present, with hyperresonance and decreased breath sounds on the involved side. Infants present with cough, wheezing, respiratory distress, and cyanosis. Older children may present with recurrent chest infections. On images obtained in neonates, the affected lobe may be slightly opacified, rather than lucent, because it is still filled with fluid. Associated cardiac anomalies occur in as many as 10% of patients.
            The most severe condition is in children in the first days of life. In newborns there are increasing dyspnea, cyanosis, convulsions, loss of consciousness. One half of the thorax is protuberant. Here there is bandbox percussion sound. Breathing is weakened or absent on auscultation. Radiologically hyper aeration of one lung, mediastinum and heart are displaced in the opposite side. Lung pattern is scanty or absent. The diaphragm is flat, excursion of it is limited, possible mediastinal hernia.





                          

Congenital lobar emphysema on the right side of the chest in a neonate. There is  marked lucent hyperexpansion in the middle lobe of the right lung; this finding is consistent with lobar emphysema. The possibility of tension pneumothorax is unlikely because lung markings are seen in this region, with splaying of the pulmonary vessels. Compressive atelectasis is present in the left upper and right lower areas of the lungs. The mediastinum and heart are shifted to the left. The osseous structures are intact.

                        

                  Congenital lobar emphysema. Lateral view in the same patient.  

                        

                                            Congenital left side lobar emphysema.


               

                  Review chest X-ray of the child with congenital emphysema of the upper lobe of left lung: pulmonary tissue of upper lobe of left lung is increased lucent, in the lower areas - reduced by compression of the lower lobe, the mediastinum is shifted to the right.

                  
                   The mediastinum is flat and shifted to the right.

               The differential diagnosis is carried out with pneumothorax, cysts, diaphragmatic hernia, hypoplasia and aspiration syndrome.
               Prognosis is poor. Children are dying too early. In milder forms the flow can be subacute and chronic. Children are retard in physical development, constantly cough and shortness of breath are observed. There are described cases of the disease with little emphysema diagnosed by chance.
              Treatment. Surgical treatment is needed in the "stress syndrome", which develops due to compression of the mediastinum. Milder forms are treated conservatively.
               Progressive airtrapping leads to respiratory and circulatory compromise in infancy. Emergency lobectomy may be required. A patient with respiratory distress whose chest radiograph reveals a hyperlucency on one side and mediastinal shift usually has a tension pneumothorax. However, one must consider congenital lobar emphysema, especially in the newborn. The diagnosis can usually be determined by looking at the edges of the hyperlucent area. In pneumothorax, the edges are convex and outline the chest wall, whereas in congenital lobar emphysema, they are concave and outline the cystic structure of an overexpanded lobe.
                Placing a chest tube in the hyperlucent airspace of congenital lobar emphysema decreases ventilation as air takes the path of least resistance out the chest tube from the bronchus rather than expanding the stiff infant lung in the remaining lobes. Prompt thoracotomy relieves the pressure inside a hyperexpanded lobe and allows the other compressed areas to ventilate. This overexpansion often stretches and dissects the bronchi and vessels, facilitating lobectomy. In cases that are detected early or surgically treated because of radiographic findings and not because of symptoms, the abnormal lobe may be difficult to identify during surgery. Therefore, in these cases, radiographs and CT scans must be carefully reviewed preoperatively.

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