Military knife syndrome

　　The cause of military knife syndrome is still unclear, but most scholars believe it is related to abnormal development of the lung during embryonic period. Pathogenesis: During the formation of lung buds, lung vessels displace, vascular drainage is malformed, which may be due to the residual connection between the embryonic venous plexus, large venous system, and umbilical yolk vein system.

　　Military knife syndrome often recurs with right lung infection. The clinical manifestations of right lung infection caused by different bacterial infections vary greatly, common symptoms include fever, cough, expectoration, accompanied or not accompanied by chest pain; severe cases may have difficulty breathing and increased respiratory rate. After the patient reaches adulthood, a right lung resection is performed, and the symptoms generally improve, without other complications.

　　Patients with different degrees of respiratory distress, which worsens during exercise, can have recurrent right lung infections, symptoms such as cough, hemoptysis, fever, and can also have chronic cough, asthma, dizziness, cyanosis. Some may have lifelong symptoms. The onset age varies, most common between 10-20 years old, with a male-to-female ratio of 1:2, and some cases have developmental abnormalities.

　　The etiology of knife syndrome is not yet clear, and it may be related to environmental factors, genetic factors, dietary factors, and emotional and nutritional factors during pregnancy. Therefore, it is not possible to prevent the disease directly by targeting the etiology. Early detection, early diagnosis, and early treatment are of great significance for indirect prevention of the disease, and can also reduce the occurrence of infection complications. For patients with existing infections, antibiotic treatment should be used as soon as possible.

　　The diagnosis of knife syndrome relies on auxiliary examinations, and the commonly used examinations in clinical practice are as follows:
　　1. X-ray examination
　　It can be seen that there is a curved sword-like shadow along the right heart margin, and there is an image of incomplete development of the right lung when the heart shifts to the right.
　　2. Bronchography and bronchoscopy
　　There may be incomplete development of the right lung and abnormal bronchial branches, narrowing and obstruction of the terminal bronchioles.
　　3. Cardiac catheterization
　　It can be seen that the right atrium has more oxygen content than the surrounding venous blood, and sometimes the catheter is directly inserted into the pulmonary vein.
　　4. Angiography
　　It can be seen that the right pulmonary artery is narrowed, and there may be a situation where arteries of the systemic circulation enter the right lung.

　　The diet of knife syndrome patients should be light, with an emphasis on vegetables and fruits, a reasonable diet, and sufficient nutrition. It is also necessary to avoid eating cold, spicy, and刺激性 food, and to avoid overeating and overdrinking. It is necessary to prevent colds and avoid catching a cold in daily life. Pay attention to frequently turning over and patting the back to promote sputum excretion and reduce the place for bacterial growth.

　　Mild cases of knife syndrome do not require special treatment. Recurrent acute and chronic pulmonary infections require active anti-infection treatment. For those diagnosed clearly, with obvious symptoms, and have already reached adulthood, right pulmonary lobectomy, right pulmonary vein to left atrium transfer surgery, right pulmonary vein to right atrium transfer surgery, or abnormal vein ligation surgery can be performed.