Saber syndrome, or pulmonary hypoplasia syndrome, also known as scimitar syndrome, was first proposed by Neil et al. (1960). The syndrome is a congenital vascular malformation, a type of pulmonary venous malformation drainage (subcardiac type), characterized by the opening of the right pulmonary vein to the inferior vena cava. It is a group of signs due to partial abnormalities of pulmonary venous return, and its main features are: hypoplasia of the right lung; scimitar-shaped shadows along the right heart margin on X-ray due to the malformed veins; and displacement of the heart to the right, approximating a right-sided heart.
The cause of this syndrome remains unclear, but most scholars believe it is related to abnormal development of the lungs during the embryonic period. The mechanism of pathogenesis is the displacement of the pulmonary vessels during the formation of the pulmonary buds and the malformation of the vascular drainage, which may be due to the remnants of the embryonic venous plexus, the large venous system, and the connecting branches between the umbilical yolk vein system. The rightward shift of the heart is associated with pulmonary volume reduction strain and is a secondary change.
The differential diagnosis should be clinically differentiated from pulmonary infections and pneumonia.
I. Special examination.
1, X-ray examination: scimitar-shaped shadow along the right heart margin is seen, and images of right lung hypoplasia are seen when the heart is shifted to the right.
2. Bronchography and bronchoscopy: right lung hypoplasia and bronchial branch abnormalities, stenosis and obstruction of the terminal fine bronchi may be present.
3.Cardiac catheterization: the right atrium is seen to have increased oxygen content compared to the surrounding venous blood. Sometimes the catheter is inserted directly into the pulmonary vein.
4.Angiography: thinning of the right pulmonary artery is seen, and there may be arteries of the body circulation system into the right lung.
II. Clinical manifestations and diagnosis
1.Symptoms
Different degrees of dyspnea, aggravated by activity, may have repeated episodes of right lung infection, cough, hemoptysis, fever and other symptoms. There can also be chronic cough, asthma, vertigo, and cyanosis. Some are asymptomatic for life. The age of onset varies. Some cases have developmental abnormalities.
2.Signs
The heart murmur can be heard in the second intercostal space at the left edge of the sternum, and the right lung breath sounds are low. The heart and lungs may also be free of abnormal signs. If the heart murmur is widespread, the possibility of other congenital heart disease should be noted.
The diagnosis can be made based on clinical manifestations and ancillary tests, and can be clinically classified as type I: those with right lung hypoplasia and blood supply to the right lung from the body circulatory system. Type II: those with right lung hypoplasia only and no blood supply to the right lung from the body circulatory system. Type III: Those who do not have complications of the above two types of malformations.
III. Treatment and prognosis
(A) Treatment
1.General treatment for those with mild symptoms, no special treatment.
2.Anti-infection recurrent acute and chronic intrapulmonary infections must be treated with active anti-infection therapy.
3, surgical treatment is not suitable for all cases. For those with clear diagnosis, obvious symptoms and adult, right pneumonectomy, right pulmonary vein to left atrium transfer, right pulmonary vein to right atrium transfer or abnormal vein ligation can be done.
(B) Prognosis
1.For those with clear diagnosis and obvious symptoms and who have reached adulthood, right pneumonectomy can be done after good.
2, complications complicating right lung infection.
3, prevention usually need to prevent cold, avoid cold.